CA1229639A - Programmer/timer for appliances - Google Patents
Programmer/timer for appliancesInfo
- Publication number
- CA1229639A CA1229639A CA000425870A CA425870A CA1229639A CA 1229639 A CA1229639 A CA 1229639A CA 000425870 A CA000425870 A CA 000425870A CA 425870 A CA425870 A CA 425870A CA 1229639 A CA1229639 A CA 1229639A
- Authority
- CA
- Canada
- Prior art keywords
- cam
- ratchet
- pawl
- eccentric
- rotation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H43/00—Time or time-programme switches providing a choice of time-intervals for executing one or more switching actions and automatically terminating their operations after the programme is completed
- H01H43/10—Time or time-programme switches providing a choice of time-intervals for executing one or more switching actions and automatically terminating their operations after the programme is completed with timing of actuation of contacts due to a part rotating at substantially constant speed
- H01H43/101—Driving mechanisms
- H01H43/102—Driving mechanisms using a pawl and ratchet wheel mechanism
Abstract
A B S T R A C T
A programmer timer (10) having motor driven cams (61, 64, 62, 66) for operating electrical switching mechanisms (102, 116, 144, 138, 126). The motor comprises a pair of spaced stator plates (24, 26) with a coil (34) and permanent magnet rotor (36) therebetween, received in a walled chamber (28) in the timer housing. Motor reduction gears (44) drive a shaft (48) for driving the ratchet wheels (72, 68) and rotary cams. The motor, gear train cams and electrical switching mechanisms are contained in a single integral housing (12). Separate concentric fast and slow ratchet wheels (72, 68) are driven by a single eccentric driven pawl (74). The center of rotation of the eccentric is positioned so that drive pawl contacts the ratchet wheel at an angle at least 10°
greater than a tangent at the contact point, for all eccentric positions, to provide ratchet wheel advance in the event of reverse rotation of the eccentric. A
bifurcated anti-reverse pawl (84) is biased against the fast and slow ratchet wheels by a spring arm (88) integral therewith. The center of rotation of the eccentric is spaced from the fast and slow ratchet wheel centers and optionally has a sub-interval cam (148) provided thereon for affecting switching. The anti-reverse pawl may optionally be pivoted about the center of rotation of the drive eccentric. The motor stator plates optionally include integrally therewith a striker arm (178, 180) and anvil (176) for cam controlled operation of a buzzer. The ratchet drive pawl alternatively is biased by a spring arm (154) formed integrallay therewith. The ratchet wheel may also optionally employ wiper contacts (200) for contacting a stationary printed circuit board.
A programmer timer (10) having motor driven cams (61, 64, 62, 66) for operating electrical switching mechanisms (102, 116, 144, 138, 126). The motor comprises a pair of spaced stator plates (24, 26) with a coil (34) and permanent magnet rotor (36) therebetween, received in a walled chamber (28) in the timer housing. Motor reduction gears (44) drive a shaft (48) for driving the ratchet wheels (72, 68) and rotary cams. The motor, gear train cams and electrical switching mechanisms are contained in a single integral housing (12). Separate concentric fast and slow ratchet wheels (72, 68) are driven by a single eccentric driven pawl (74). The center of rotation of the eccentric is positioned so that drive pawl contacts the ratchet wheel at an angle at least 10°
greater than a tangent at the contact point, for all eccentric positions, to provide ratchet wheel advance in the event of reverse rotation of the eccentric. A
bifurcated anti-reverse pawl (84) is biased against the fast and slow ratchet wheels by a spring arm (88) integral therewith. The center of rotation of the eccentric is spaced from the fast and slow ratchet wheel centers and optionally has a sub-interval cam (148) provided thereon for affecting switching. The anti-reverse pawl may optionally be pivoted about the center of rotation of the drive eccentric. The motor stator plates optionally include integrally therewith a striker arm (178, 180) and anvil (176) for cam controlled operation of a buzzer. The ratchet drive pawl alternatively is biased by a spring arm (154) formed integrallay therewith. The ratchet wheel may also optionally employ wiper contacts (200) for contacting a stationary printed circuit board.
Description
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Background of the Invention The present invention relates to programmer timers for appliances such as dishwashers, clothes washers, and clothes driers. Appliances of this type commonly utilize a synchronous timing motor to drive a cam mechanism for actuating a plurality of cam follower t actuated switches for making and breaking individual electrical circuits for various control functions of the appliance Programmer timers of this type operate to control the appliance function in timed sequence and duration for providing a preselected program cycle of appliance operation It is known to provide appliance programmer timers having a plurality of rotary cams mounted for rotation about a common axis with the cam being rotationally advanced by a stepping mechanism. In programmer/timers of this known type, ratchet wheels are provided for advancing the rotary cams and a motor driven oscillating paw engages the ratchet wheel for step-by-step advancement of the I The advance paw may be driven by a rotating eccentric or crankshaft attached to a suitable gear reduction mechanism driven by the synchronous -timing motor.
Renown programmer/timers employing a synchronous timing motor have employed a ratchet mechanism in the synchronous motor to prevent reverse rotation startup of the motor which is an inherent feature of a synchronous motor. This ~ntireverse feature in the motor ha been necessitated in order to prevent reverse rotation of the drive mechanism for the ratchet advance paw. Where the ratchet advance paw is driven by a rotating crank or I
eccentric, reverse rotation of the eccentric has caused the drive paw to "kick outyell or disengage from the ratchet teeth and thereby malfunction in advancing the cam.
In programmer/timers for appliances, it is known to provide axially adjacent ratchet wheels having different pitch diameters for the peripheral teeth thereof but utilize the same pitch for the teeth of both wheels in order that a inlay drive paw may actuate both ratchet wheels. It is Allah known to provide an intermittent series of deeper notches on one ratchet wheel to permit the drove paw to periodically advance the first and second ratchet wheels together for a single step. This arrangement provides for faster advancement of the cam attached to the ratchet having the greater tooth pitch diameter than the cam attached to the second ratchet wheel.
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Moreover, it has been desired to provide a programmer timer having a convenient low cost means for providing actuation of a separate cam follower at sub-intervals of advancement ox the main ratchet wheel.
Sub-interval cam follower actuation may then be employed to modify the actuation of a set of contacts actuated by either the fast or slow cam wheel or to actuate a separate set of electrical contacts.
Appliance programmer/timers have heretofore employed a separate timing motor attached to a housing which contained the escapement, cams, cam followers and electrical contacts. the gear reduction mechanism for driving the escapement has heretofore usually been incorporated in the separate motor housing. This ~9~3~
arrangement permits separate assembly of the motor and timer mechanism; however, such an arrangement has the disadvantage of increased cost associated with separate housings for -the motor and the timer mechanism.
Thus, it has been desired to provide an appliance programmer timer having a synchronous motor driven cam advance mechanism which eliminates the need for an anti-reverse directional ratchet mechanism on the timing motor and accom-mediates rotation of the timing motor in either direction without malfunction of the escapement. It has further been desired to provide a low cost programmer timer with the motor and timer assembled as a unit in an integral housing thereby eliminating the need for separate motor and timer housings. It has further been desired to provide a simple and low cost programmer timer having a sub-interval timed electrical switching function with relation to the timing interval employed for the main switching sequence.
According to the present invention there is provided a device for electrical switching in timed sequence.
According to one aspect of the invention the device includes a primary and secondary cam means rotatable mounted on a housing about respectively first and second spaced centers of rotation. An electrical switch means is provided which includes primary cam follower means responsive to movement of the primary cam means for affecting electrical switching of contacts in accordance with a first programmed sequence. A secondary cam follower means is responsive to the second cam means for alternating the electrical switching in accordance with a second programmed sequence. A ratchet and paw means is operative to cause rotation of the primary cam means and includes a ratchet wheel rotatable about the first center and a drive paw orbital about the second center.
Drive means is rotatable about the second center to cause the paw to index the ratchet.
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~;29639 According to another aspect of the present invention, there is provided primary cam means including a ratchet wheel rotatable mounted on a housing with a primary cam follower means responsive to movement of the cam means and operative for effecting movement of one of a first set of electrical contacts. Drive means is provided for advancing the cam means, the drive means including a drive paw pivot ably mounted on the housing about a point spaced from the center of rotation of the cam means, the paw means contacting the ratchet wheel. The drive means further has eccentric means rotatable for driving the paw and sub-interval cam means mounted on the housing means for rotation about a common center with the eccentric means. Motor means is operative to rotate the sub-interval cam means and the eccentric means for effecting movement of the paw for advancing the ratchet wheel. A second cam follower means is operative in response to rotation of the sub-interval cam means to effect sub-interval movement of one of the set of electrical contacts.
The present invention may be used as an appliance programmer timer.
The programmer timer according to a specific embodiment of the present invention employs a unique integral timer-motor housing wherein the motor comprises a pair of spaced parallel stators plates received in a walled cavity in the housing and registered for alignment therein with the motor coil and rotor disposed between the parallel stators plates. The present invention employs the motor described in cop ending Canadian application Serial No. 401,872 filed April 28, 1982 (now abandoned) entitled "Synchronous Motor"
and assigned to the assignee of the present invention. The housing in one embodiment of this arrangement has a deck, or wall, portion separating the motor from the gear reduction, cams, escapement, cam followers and electrical contacts.
The arrangement thus permits assembly of the motor on one side of the housing and assembly of the escapement, cams mob`\
~9~39 and contacts on the other side of the housing to thereby provide a unified assembly of the programmer timer and minimize manufacturing costs. An alternative embodiment of the integral housing for the motor and timer permits the motor, cams, contacts and escapement to be assembled from one side of the housing.
More specifically, the cam advance escapement in the present invention may employ an eccentric driven paw which engages the ratchet wheel or wheels such that the direction of motion of the paw forms an angle with the tangent to the ratchet, at the point of contact, of not less than 10. This arrangement of the paw and ratchet permits the paw to advance the ratchet wheel normally even if the eccentric paw drive mechanism is rotated in a reverse manner by synchronous timing motor.
The present invention thus provides a unique and low cost programmer timer having a novel means for providing timed interval switching functions and sub-interval switching functions and accommodates forward and reverse rotation of a synchronous timing motor without malfunction. The present invention also employs a unique arrangement for the synchronous timing motor and timer housing to permit assembly of the motor and timer mechanism in a unified housing arrangement.
The cam advance mechanism of the present invention may employ a unique anti-reverse paw biased against the cam advance ratchet by an integral spring finger. The present invention optionally employs a unique integral spring-ratchet paw for preventing the operator from manually reversing the cam and advance ratchet during program selection. The escapement of the present invention optionally employs a ratchet advance paw having an integral spring finger for biasing the paw against the ratchet. Another optional feature provides a unique alarm buzzer formed integrally with the motor stators plates.
~2~39 A Brief Description of the Drawings FIGURE 1 is a plan view of the programmer/timer of the present invention with the housing cover removed for purposes of illustration;
FIGURE 2 is a section view taken along section-indicating lines 2-2 of Figure l;
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FIGURE 3 is a view taken along section-indicating lines 3-3 of Figure 1;
FIGURE 4 is a section view taken along section indicating lines 4-4 of Figure and shows the . motor and gear reduction installed in the integral housing; 4 .
FIG S is a portion of a view similar to Figure 1 and shows an alternate embodiment of the escapement;
FIGURE 6 is a portion of a view similar to Figure 1 and shows another emdobiment of the escapement;
FIGURE 7 is a portion of a view taken along section indicting lines 7-7 of Figure 4 and shows the optional buzzer;
FIGURE 8 is a partial view taken along.
section-indicating lines 8-8 of Figure 7;
FIRE 9 is a partial view taken along section-indicating lines 9-9 of Figure 8;
FIRE 10 is a partial view similar to Figure 4 and illustrates an alternate embodiment employing a stationary printed circuit board having rotating wipers for auxiliary switching functions and an alternate housing arrangement for the motor and timer mechanism;
Figure 11 is a partial view taken along section indicating lines 11-11 ox Figure 10;
Phony 12 is a partial plan view taken along section-indicating lines 12-12 of Figure 10 illustrating an optional push-to Start switch feature;
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FIGURE 13 is a partial view taken along section indicating lines 13-13 of Figure 12;
FIGURE 14, which appears on the same sheet of drawings as Figure 9, is a partial section view taken along section-indicating lines 14-14 of Figure 1; and FIGURE 15 is a portion of a plan view of an alternate arrangement of the embodiment of Figure 1.
Detailed Description:
Referring now to Figures 1, 2, 3 and 4, the programmer timer of the present invention is indicated generally at 10 as having a housing 12 having formed integrally therewith (see 4) a timer cavity 14 and a motor cavity 16 which are separated by a dividing wall portion 18. The timer cavity 14 has a cover plate 20 received there over and retained by a suitable means, such as snap locks 22, formed integrally with the housing 12. The timer cavity 14 is shown in plan view in Figure 1 with the cover plate 20 omitted for clarity.
The motor cavity 16 has received therein a pair of spaced motor stators plates 24, 26 which are registered against the inner periphery of the cavity wall 28 and received over a plurality of shouldered posts shown typically at 30. The stators plates are retained thereon by suitable fasteners such as clips 32. A motor coil assembly, indicated generally at 34, is received between the stators plates in side-by-side relationship with a permanent magnet rotor assembly, indicated generally at 36, having axle pin 38 journal Ed at its upper end in housing wall 18 and in stators plate 26 at its lower end. A plurality of interdigitated stators poles 40 are formed mob ~.~2~63~
integrally in the stators plates and surround the rotor assembly. A suitable ferromagnetic core 42 is provided for completing the flux path between the stators plates to permit synchronous operation of the motor.
Stators plate 24 is spaced from the housing wall 18 by an amount suitable to permit the incorporation of a gear train, indicated generally at 44, which is driven by rotor pinion 46 which extends through an aperture in stators plate 24 and is attached to the rotor 36. The output of the gear train 44 is through shaft 48 journal Ed for rotation on a post 50 formed on the housing wall 18 which post So extends upward into timer cavity 14. Shaft 48 has an eccentric 52 provided thereon and has its upper end journal Ed for rotation in aperture 54 provided in the housing cover 20.
A timer cam wheel 56 is received in timer cavity 14 and has a stub shaft 58 journal Ed in an aperture formed in housing wall 18 and spaced from the center of rotation of shaft 48. Wheel 56 also has a shaft 60 extending therefrom in direction opposite stub shaft 58 and through an aperture in housing cover 20. Shaft 60 is adapted for manual rotation by the appliance operator for suitable cycle program selection. In the presently preferred practice wheel 56 has a plurality of peripheral cam tracks 61, 64 and 66 provided thereon and has concentric therewith and axially adjacent a toothed ratchet surface 68 provided about the periphery thereof.
A second ratchet wheel 70 is received over shaft 60 for free rotation with respect to wheel 56 and wheel 70 also has a toothed ratchet surface 72 provided about the periphery thereof.
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g Eccentric 52 has one end of a drive paw 74 received there over for reciprocal (orbital) movement thereof upon rotation of shaft 48. The free end of paw 74 has a ratchet engaging tooth 76 provided thereon which tooth is sufficient in width to engage both ratchet 68 and ratchet 72.
Referring in particular to Figure 1, the teeth of ratchet 72 has a pitch diameter slightly larger than ratchet 68. In the presently preferred practice ratchet 72 intermittently contains a deep notch 78 at a desired interval, or multiple of teeth, such that upon the paw tooth 76 engaging the deep notch, paw 74 drops to a position whereupon the ratchet tooth 76 engages simultaneous lye ratchet 72 and ratchet 68 to thereby index both ratchet wheels together for a single stroke. Thus, the single paw 74 provides continuous indexing of wheel 70 and intermittent indexing of wheel 56, dependent upon the number and spacing of deep notches provided in ratchet 72.
With continuing reference to Figure 1, gear box output shaft 48 rotates about a center of rotation nay and eccentric 52 is eccentric to point "An. In the presently preferred practice, the eccentric drive surface 52 is formed by a circular surface on shaft 48 having a center of rotation I displaced from shaft center "A" by an amount equal to the dimension "By. The indexing mechanism thus yields a longitudinal stroke for paw 74 equal to twice the amount of By In order for the drive paw 74 to function properly, irrespective of the direction of rotation of eccentric 52, it is necessary that the angle of contact of Z2963~
drive paw 74 with the ratchets 72, 68 be greater than a tangent angle to the ratchet at the point of contact of paw tooth 76. This is illustrated in Figure 1 wherein a line through the center of excursion "C" of eccentric 52 is shown to make an angle 0 with the tangent to the ratchet at the point of contact of paw tooth 76.
In order to prevent paw tooth 76 from disengaging or kicking out" of the teeth of the ratchet, for all positions of center of excursion I of eccentric 52, it is necessary that the angle 0 be approximately 10 degrees or greater. This means that for all positions of center of excursion "C" as eccentric 52 rotates either clockwise or counterclockwise, a line through center "C"
and the point of contact of paw tooth 76 with the ratchet must make an angle of at least 100 degrees with a radius to the ratchet at the point of tooth contact. The "bite"
of paw tooth 76 is maximized when the driving stroke occurs with center of excursion "C" of eccentric 52 above the center of rotation AYE of shaft 48, as viewed in Figure 1.
The arrangement for the indexing mechanism shown in Figure 1 gives the paw tooth 76 sufficient "bite" on the ratchet teeth to prevent malfunction of paw 74 in the event of counterclockwise rotation of eccentric 52, it being understood that in normal operation eccentric 52 rotates in a clockwise direction as viewed in Figure 1 in order to maximize the "bite" of the paw tooth 76.
Referring now to Figures 1 and 2, an anti reverse paw having hub 80 is pivotal received over a mounting post 82 extending from the wall 18 of the timer housing.
Paw 80 has a pair of generally parallel spaced fingers ;39 84, 86 extending from the hub thereof with paw 84 contacting a larger diameter ratchet 72 and finger 86 contacting smaller ratchet 68 such that any attempt to rotate the ratchets counterclockwise as shown in Figure 1 would be resisted by the "bite of the fingers 84, 86 sufficient to prevent counterclockwise rotation of the ratchet Paw 80 has a third finger 88 formed integrally with the hub 80 and extending rightwardly in Figure 1 which registers against a shouldered portion 90 provided integrally in the housing wall 18. In the presently preferred practice, the paw finger 88 is formed of resilient material such that it comprises a spring reloaded against lug 90 to provide torque on paw hub 80 to thereby bias the paw fingers 84, 86 into contact with ratchets 68, 72. It will be understood however to those skilled in the art that although paw finger 88 is formed of rigid material in the embodiment described, fingers 84, 86 may alternatively be formed of resilient material to thereby provide a reload of the fingers against the ratchet teeth.
Alternatively, as will hereinafter be described, anti reverse paw 80 may be pivotal mounted about the center of rotation "A" of drive shaft 48 to give the anti reverse paw and the main drive paw 74 a common reference point for attacking the ratchet teeth.
Functionally, this alternate arrangement facilitates varying the stroke of the advance paw 74 and yet permits the anti reverse paw to properly engage the ratchet teeth irrespective of the stroke of the advance paw.
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Referring again to Figure 1, the slower or main ratchet 68 can optionally have a raised tooth portion 92 having the same tooth pitch and pitch diameter as the teeth of ratchet 72 such that, at a selected position on the program cam wheel 56, the drive paw tooth 76 engages raised tooth 92 to provide a single one-step advance of the wheel 56 at a position separate from the deep notches 78.
Referring now to Figures 1, 3 and 4, the main or slow ratchet wheel 56 has the cam track 61 thereof engaged by a cam follower 94 having a cam engaging tooth 96 and being pivotal mounted about a post 98 extending upwardly from the wall 18 of the timer housing. Track 62 of the cam wheel 56 is engaged by cam follower 100 having a cam engaging tooth 102 with the follower 100 pivoted about post 82 (see also Fig. 2). Cam track 64 is engaged by tooth 104 provided in cam follower 106 pivotal received over post 980 Cam track 66 is engaged by tooth 108 of cam follower 110 which is pivotal mounted about post 82 tree Fig. 2).
Cam follower 94 has formed integrally therewith a lug 112 operative to contact for movement an electrical switch contact arm 114 having a movable contact 116 provided thereon for alternately making and breaking a circuit with stationary contacts 118, 120.
Cam follower 100 has a lug 122 extending integrally therefrom which Contacts a movable electrical switch arm 124 having a movable contact 126 provided thereon. Lug 122 is operative upon movement of the follower 100 to move contact 126 alternately between stationary contacts 128, 130 for` making and breaking 963~
electrical contact there between as desired for the appliance cycle program.
Cam follower 106 has a lug 132 extending integrally therefrom which upon motion of follower 106 contacts a movable contact arm 134 having a movable contact 136 provided thereon for making and breaking electrical contact wit a stationary contact 138.
Cam follower 110 has an integral lug 140 extending therefrom operative to contact a movable switch arm 142 having a movable contact 144 provided thereon for making and breaking an electrical circuit with stationary contact 146.
The programmer/timer of the present invention thus provides in the embodiment of Figures 1 and 4 a fast and slow ratchet operative to drive a main cam wheel 56 and a secondary cam surface 70 (see Fig. 4) attached to the fast ratchet 72. In the embodiment of Figure 1, cam follower tooth 102 on cam follower 100 has sufficient width to ride the track of cam 70 on the fast ratchet wheel so as to be responsive to notches thereon for permitting contact of movable electrical contact 126 with stationary contact 130 as required by the appliance cycle program.
To will be understood to those skilled in the art however, that as between cam track 70 and cam track 62, the sequence of events and positioning contact 126 by contact of the cam follower lug 122 with arm 124 may vary as desired to provide numerous combinations. For example, movable contact 126 may generally be positioned intermediate contacts 128 and 130 by cam track 62 and it operative thereby to intermediately make contact with stationary contact 130; and, responsive to cam track 70 on the fast ratchet wheel to make contact with contact 128 or to periodically make a circuit with stationary contact 130.
Alternatively, cam track 70 may be employed to make a circuit with stationary contact 130 and cam 62 may be employed only to make and break a circuit with contact 128. The particular choice of sequencing of contacts 126, 128 and 130 responsive to cam tracks 62 and 70 will be governed by the requirements of the program cycle of the particular appliance.
Referring now to Figure 5, an alternate embodiment, indicated generally at 10', of the timer of Figure 1 it shown wherein the shaft 48 about which eccentric: 52 rotates, has an auxiliary cam track 148 provided thereon for rotation with shaft 48 about point "A. A drive paw 150 has one end thereof received over eccentric 52 for orbital movement therewith and has a drive tooth 152 formed integrally therewith for engaging the ratchet on wheel 56. Pal 150 has formed integrally therewith a resilient spring member 154 which extends from the pivot center nay in a direction opposite of paw 150;
and, finger 154 is registered against a lug 156 provided integrally from housing wall 18. The finger 154 is reloaded by an amount to sufficient provide the necessary bias to maintain the drive paw tooth 152 in engagement with the ratchet.
cam follower 158 it pivotal mounted about a post 160 extend no from the housing wall 18. Cam follower 158 has a portion extending from post 160 in a direction ~2~3~
opposite the cam track 148 which portion has a lug 162 formed thereon for contacting the movable contact arm 124. In operation, as drive shaft 48 rotates, cam track 148 causes cam follower 158 to pivot which in turn causes lug 162 to move the contact 126 toward and away from stationary contact 130. The cam track 148 thus operates as a sub interval cam for movement of the movable electrical contact 1~6 with respect to the main interval operation of contact 126 by cam follower lug 122.
Referring now to Figure 6, another alternate arrangement of the timer of Figure 1 is indicated generally at 10" wherein a main drive paw 164 is pivotal received over eccentric 52 which is driven by shaft 48 by rotation about pivot center "A" for orbital movement of the paw 164. Integral drive tooth 166 on paw 164 contacts the ratchet on wheel 56 for causing indexed movement thereon. Shalt 48 also has auxiliary cam 148 provided thereon for movement of cam follower 158 for effecting subinter~al movement of contact 126 in similar fashion to the embodiment of Figure 5.
In the embodiment of Figure 6, the main drive paw 164 preferably has an integral spring finger 168 extending outwardly from the end of drive paw 164 containing ratchet contacting tooth 166. spring finger 168 is registered against a stationary lug 170 extending from the wall 118 of the timer housing. The spring finger 168 is reloaded by a desired amount to provide suitable bias of the paw tooth 166 into contact with the ratchet wheel.
Referring again to Figure 1, a still further alternate embodiment of the stepping mechanism of the Lowe present invention is illustrated wherein the drive paw 74 has an arm portion 172 extending therefrom in a direction angularly spaced from arm 74 with one end of a reload spring 174 connected thereto. The opposite end of spring 174 is anchored to a stationary post 176 extending from the wall 18 of the timer housing such that spring 174 is tensioned to provide a reload of paw arm tooth 76 against the ratchet on wheel 56.
Referring now to Figures 7, B and 9, an optional buzzer is illustrated as formed integrally with the motor stators plates in the timer construction of the present invention.
As illustrated in Figure 7 the outer stators plate 26 has formed integrally with one edge thereof an anvil 176; and, as shown in Figure 8 a striker arm 178 is formed integrally with one edge of the opposite stators plate 24, with the striker 176 extending in the free position in spaced parallel arrangement with striker 178.
The striker arm 178 has a cam follower portion 180 formed preferably integrally therewith and extending therefrom through an aperture 182 formed in the wall 18 of the timer housing. The cam follower portion 180 makes contact with one of the cam tracks on main cam wheel 56 as for example, cam track 66.
In operation, when the cam track 66 releases cam follower 180 from a position biased away from anvil 176, the alternating current excitation of the magnetic yield in Syria plates 24, 26 causes the striker arm 178 to vibrate against anvil 176 thereby giving an audible alarm.
~zc~3g Referring now to Figure 10, an alternate embodiment of the timer of Figure 1 is indicated generally at 190 as having a unitary housing 192 having a deep-well configuration with wall 194 about the periphery thereof and open to one side. Motor plates 24, 26 are received therein in spaced parallel arrangement, with the rotor assembly indicated generally at 36 and coil assembly indicated generally at 34 received therebetwèen with the stators plates received over posts shown typically at 193 and retained thereon by clips 32.
In the embodiment of Figure 10, the gear train indicated generally at 196 is assembled into the housing 192 from the opened side thereof, the motor stators plates, rotor and coil are assembled therein and the fast ratchet wheel 197 and slow or ratchet and wheel 195 containing the four main cam tracks are then assembled into the housing in side-by-side arrangement with the motor stators plates as shown in Figure 10.
The escapement mechanism and contact arms are also assembled into the housing 192 from the open side thereof and a cover plate 198 is then secured there over.
referring now to Figures 10 and 11, the main cam wheel has a plurality of rotating wiper arms 200 secured thereto by suitable fasteners such as rivets 202 and the wiper arms contact a stationary printed circuit board 204 secured to the inside of cover plate 198. Thus the embodiment of Figure 10 employs additional switching functions on the same cam wheel by incorporating rotating wipers for switching between contacts provided on a stationary printed circuit board. It will be understood however that alternatively, the printed circuit board 204 9~3~31 may be secured to the rotating cam wheel l9S and the wipers 200 may be secured in a stationary manner to the inside of housing cover plate 198.
Referring now to Figures 10, I and 13, the push-to-start feature of the timer 190 is illustrated wherein the main shaft 206 for cam wheel 195 may be pushed axially by the appliance operator from the position shown in solid outline in Figures 10 and 13 to the position shown therein in dashed outline. The shaft 206 has a circular cam surface 208 provided thereon adjacent the end nearest the wall 192 of the housing and a slid able cam follower 210 is engaged by the cam surface 208. A movable contact arm 212 having a movable electrical contact 214 thereon registers against cam follower 210 and has the stationary end thereof connected to an electrical connecting terminal 216 which extends to the exterior of the housing.
A stationary electrical contact 218 is attached to one end of an electrical collecting terminal 220 which also extends through the wall 192 of the housing for external attachment thereto. In operation, as the shaft 206 is moved axially by the operator to the position indicated in dashed outline, cam surface 208 moves follower 210 which causes arm 212 to move stationary contact 214 to make electrical connection with contact 218 Jo complete the circuit to the power source for energizing machine operation.
By pushing the shaft 206 tube appliance operator can complete the line power circuit irrespective of the position of the rotary cam wheel 195. Thus, the timer motor may be energized irrespective of the position of the ~963~
electrical switching contacts associated with the cam wheel 195 and the cam wheel 197.
The embodiment of Figure 10 permits assembly of the motor, gear train, stepping mechanism, rotary cams and ratchet wheels and cam followers and contacts all from one side of the timer housing without reversing the position of the timer housing during assembly. The additional advantage of the embodiment of Figure 10 is that the gear train 196 may be assembled in the housing without the power output shaft thereof extending through the wall of the housing. The embodiment of Figure 10 also eliminates the need for journaling one end of the output shaft in the cover of the timer housing as is the case in the embodiment of Figure 4.
Referring now to Figure 14, the arrangement of a typical contact arm with integral electrical connecting terminals is shown, wherein a an arm portion 222 see Fig.
1) has a folded double thickness portion 224 provided thereon and extending at right angles from portion 222.
The folded portion 224 extends through an aperture 226 provided in the wall 18 of the housing and is adapted for external electrical connection thereto. The folded portion 22~ of the arm 222 is received in a slot form by spaced guide surfaces 228, 230 formed integrally with a raised portion indicated generally at 232 provided in the timer housing. The arrangement of Figure 14 thus provides a unitary electrical connecting terminal and contact arm arrangement which is retained by simple sliding engagement with guide surfaces formed in the timer housing.
Referring now to Figure 15, an alternate arrangement of the embodiment of Figure 1 of the invention 1~29~39 is shown wherein the anti reverse member 222 is received on shaft 48 for pivotal movement about the center of rotation 'AYE of shaft I Member 22~ has a paw finger 224 which engages the ratchet 68 for preventing reverse rotation thereof by the appliance operator. Member 222 preferably has a resilient spring finger 226 provided integrally therewith which spring finger is registered against a lug 228 extending from the wall 18 of the housing. The spring finger 226 is reloaded to bias the paw 224 into engagement with the ratchet 68. The arrangement of Figure thus provides a common pivot reference for the main drive paw and the anti reverse member.
The present invention thus provides a unique appliance programmer-timer having a motor and cam driven electrical switching mechanism assembled in a unitary housing. The programmer-timer of the present invention employs a stepping mechanism for advancing the electrical switching cams. The stepping mechanism employs an eccentric-driven advancement paw for indexing a ratchet wherein the advancement paw will accommodate reverse rotation of the driving eccentric without malfunction of the advance mechanism. The timer of the present invention employs a unique anti reverse ratchet paw having an integral bias spring for preventing reverse rotation of the programming cam by the appliance operator. Optional features of the programmer-timer of the present invention include an auxiliary sub interval cam provided on the shaft driving the eccentric for the advance paw and an optional buzzer having a striker and anvil formed integrally with the motor stators plates. The present invention employs an optional drive paw having integral bias spring finger formed therewith. An optional rotating printed circuit board-wiper arrangement is provided for the cam wheels for additional switching functions.
~9639 -21- .
Although the invention has hereinabove been described in the presently preferred practice, it will be understood by those having skill in the art, that the invention is capable of modifications and variations all of which are deemed to be encompassed by the invention as defined by the following claims.
Background of the Invention The present invention relates to programmer timers for appliances such as dishwashers, clothes washers, and clothes driers. Appliances of this type commonly utilize a synchronous timing motor to drive a cam mechanism for actuating a plurality of cam follower t actuated switches for making and breaking individual electrical circuits for various control functions of the appliance Programmer timers of this type operate to control the appliance function in timed sequence and duration for providing a preselected program cycle of appliance operation It is known to provide appliance programmer timers having a plurality of rotary cams mounted for rotation about a common axis with the cam being rotationally advanced by a stepping mechanism. In programmer/timers of this known type, ratchet wheels are provided for advancing the rotary cams and a motor driven oscillating paw engages the ratchet wheel for step-by-step advancement of the I The advance paw may be driven by a rotating eccentric or crankshaft attached to a suitable gear reduction mechanism driven by the synchronous -timing motor.
Renown programmer/timers employing a synchronous timing motor have employed a ratchet mechanism in the synchronous motor to prevent reverse rotation startup of the motor which is an inherent feature of a synchronous motor. This ~ntireverse feature in the motor ha been necessitated in order to prevent reverse rotation of the drive mechanism for the ratchet advance paw. Where the ratchet advance paw is driven by a rotating crank or I
eccentric, reverse rotation of the eccentric has caused the drive paw to "kick outyell or disengage from the ratchet teeth and thereby malfunction in advancing the cam.
In programmer/timers for appliances, it is known to provide axially adjacent ratchet wheels having different pitch diameters for the peripheral teeth thereof but utilize the same pitch for the teeth of both wheels in order that a inlay drive paw may actuate both ratchet wheels. It is Allah known to provide an intermittent series of deeper notches on one ratchet wheel to permit the drove paw to periodically advance the first and second ratchet wheels together for a single step. This arrangement provides for faster advancement of the cam attached to the ratchet having the greater tooth pitch diameter than the cam attached to the second ratchet wheel.
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Moreover, it has been desired to provide a programmer timer having a convenient low cost means for providing actuation of a separate cam follower at sub-intervals of advancement ox the main ratchet wheel.
Sub-interval cam follower actuation may then be employed to modify the actuation of a set of contacts actuated by either the fast or slow cam wheel or to actuate a separate set of electrical contacts.
Appliance programmer/timers have heretofore employed a separate timing motor attached to a housing which contained the escapement, cams, cam followers and electrical contacts. the gear reduction mechanism for driving the escapement has heretofore usually been incorporated in the separate motor housing. This ~9~3~
arrangement permits separate assembly of the motor and timer mechanism; however, such an arrangement has the disadvantage of increased cost associated with separate housings for -the motor and the timer mechanism.
Thus, it has been desired to provide an appliance programmer timer having a synchronous motor driven cam advance mechanism which eliminates the need for an anti-reverse directional ratchet mechanism on the timing motor and accom-mediates rotation of the timing motor in either direction without malfunction of the escapement. It has further been desired to provide a low cost programmer timer with the motor and timer assembled as a unit in an integral housing thereby eliminating the need for separate motor and timer housings. It has further been desired to provide a simple and low cost programmer timer having a sub-interval timed electrical switching function with relation to the timing interval employed for the main switching sequence.
According to the present invention there is provided a device for electrical switching in timed sequence.
According to one aspect of the invention the device includes a primary and secondary cam means rotatable mounted on a housing about respectively first and second spaced centers of rotation. An electrical switch means is provided which includes primary cam follower means responsive to movement of the primary cam means for affecting electrical switching of contacts in accordance with a first programmed sequence. A secondary cam follower means is responsive to the second cam means for alternating the electrical switching in accordance with a second programmed sequence. A ratchet and paw means is operative to cause rotation of the primary cam means and includes a ratchet wheel rotatable about the first center and a drive paw orbital about the second center.
Drive means is rotatable about the second center to cause the paw to index the ratchet.
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~;29639 According to another aspect of the present invention, there is provided primary cam means including a ratchet wheel rotatable mounted on a housing with a primary cam follower means responsive to movement of the cam means and operative for effecting movement of one of a first set of electrical contacts. Drive means is provided for advancing the cam means, the drive means including a drive paw pivot ably mounted on the housing about a point spaced from the center of rotation of the cam means, the paw means contacting the ratchet wheel. The drive means further has eccentric means rotatable for driving the paw and sub-interval cam means mounted on the housing means for rotation about a common center with the eccentric means. Motor means is operative to rotate the sub-interval cam means and the eccentric means for effecting movement of the paw for advancing the ratchet wheel. A second cam follower means is operative in response to rotation of the sub-interval cam means to effect sub-interval movement of one of the set of electrical contacts.
The present invention may be used as an appliance programmer timer.
The programmer timer according to a specific embodiment of the present invention employs a unique integral timer-motor housing wherein the motor comprises a pair of spaced parallel stators plates received in a walled cavity in the housing and registered for alignment therein with the motor coil and rotor disposed between the parallel stators plates. The present invention employs the motor described in cop ending Canadian application Serial No. 401,872 filed April 28, 1982 (now abandoned) entitled "Synchronous Motor"
and assigned to the assignee of the present invention. The housing in one embodiment of this arrangement has a deck, or wall, portion separating the motor from the gear reduction, cams, escapement, cam followers and electrical contacts.
The arrangement thus permits assembly of the motor on one side of the housing and assembly of the escapement, cams mob`\
~9~39 and contacts on the other side of the housing to thereby provide a unified assembly of the programmer timer and minimize manufacturing costs. An alternative embodiment of the integral housing for the motor and timer permits the motor, cams, contacts and escapement to be assembled from one side of the housing.
More specifically, the cam advance escapement in the present invention may employ an eccentric driven paw which engages the ratchet wheel or wheels such that the direction of motion of the paw forms an angle with the tangent to the ratchet, at the point of contact, of not less than 10. This arrangement of the paw and ratchet permits the paw to advance the ratchet wheel normally even if the eccentric paw drive mechanism is rotated in a reverse manner by synchronous timing motor.
The present invention thus provides a unique and low cost programmer timer having a novel means for providing timed interval switching functions and sub-interval switching functions and accommodates forward and reverse rotation of a synchronous timing motor without malfunction. The present invention also employs a unique arrangement for the synchronous timing motor and timer housing to permit assembly of the motor and timer mechanism in a unified housing arrangement.
The cam advance mechanism of the present invention may employ a unique anti-reverse paw biased against the cam advance ratchet by an integral spring finger. The present invention optionally employs a unique integral spring-ratchet paw for preventing the operator from manually reversing the cam and advance ratchet during program selection. The escapement of the present invention optionally employs a ratchet advance paw having an integral spring finger for biasing the paw against the ratchet. Another optional feature provides a unique alarm buzzer formed integrally with the motor stators plates.
~2~39 A Brief Description of the Drawings FIGURE 1 is a plan view of the programmer/timer of the present invention with the housing cover removed for purposes of illustration;
FIGURE 2 is a section view taken along section-indicating lines 2-2 of Figure l;
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I
FIGURE 3 is a view taken along section-indicating lines 3-3 of Figure 1;
FIGURE 4 is a section view taken along section indicating lines 4-4 of Figure and shows the . motor and gear reduction installed in the integral housing; 4 .
FIG S is a portion of a view similar to Figure 1 and shows an alternate embodiment of the escapement;
FIGURE 6 is a portion of a view similar to Figure 1 and shows another emdobiment of the escapement;
FIGURE 7 is a portion of a view taken along section indicting lines 7-7 of Figure 4 and shows the optional buzzer;
FIGURE 8 is a partial view taken along.
section-indicating lines 8-8 of Figure 7;
FIRE 9 is a partial view taken along section-indicating lines 9-9 of Figure 8;
FIRE 10 is a partial view similar to Figure 4 and illustrates an alternate embodiment employing a stationary printed circuit board having rotating wipers for auxiliary switching functions and an alternate housing arrangement for the motor and timer mechanism;
Figure 11 is a partial view taken along section indicating lines 11-11 ox Figure 10;
Phony 12 is a partial plan view taken along section-indicating lines 12-12 of Figure 10 illustrating an optional push-to Start switch feature;
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FIGURE 13 is a partial view taken along section indicating lines 13-13 of Figure 12;
FIGURE 14, which appears on the same sheet of drawings as Figure 9, is a partial section view taken along section-indicating lines 14-14 of Figure 1; and FIGURE 15 is a portion of a plan view of an alternate arrangement of the embodiment of Figure 1.
Detailed Description:
Referring now to Figures 1, 2, 3 and 4, the programmer timer of the present invention is indicated generally at 10 as having a housing 12 having formed integrally therewith (see 4) a timer cavity 14 and a motor cavity 16 which are separated by a dividing wall portion 18. The timer cavity 14 has a cover plate 20 received there over and retained by a suitable means, such as snap locks 22, formed integrally with the housing 12. The timer cavity 14 is shown in plan view in Figure 1 with the cover plate 20 omitted for clarity.
The motor cavity 16 has received therein a pair of spaced motor stators plates 24, 26 which are registered against the inner periphery of the cavity wall 28 and received over a plurality of shouldered posts shown typically at 30. The stators plates are retained thereon by suitable fasteners such as clips 32. A motor coil assembly, indicated generally at 34, is received between the stators plates in side-by-side relationship with a permanent magnet rotor assembly, indicated generally at 36, having axle pin 38 journal Ed at its upper end in housing wall 18 and in stators plate 26 at its lower end. A plurality of interdigitated stators poles 40 are formed mob ~.~2~63~
integrally in the stators plates and surround the rotor assembly. A suitable ferromagnetic core 42 is provided for completing the flux path between the stators plates to permit synchronous operation of the motor.
Stators plate 24 is spaced from the housing wall 18 by an amount suitable to permit the incorporation of a gear train, indicated generally at 44, which is driven by rotor pinion 46 which extends through an aperture in stators plate 24 and is attached to the rotor 36. The output of the gear train 44 is through shaft 48 journal Ed for rotation on a post 50 formed on the housing wall 18 which post So extends upward into timer cavity 14. Shaft 48 has an eccentric 52 provided thereon and has its upper end journal Ed for rotation in aperture 54 provided in the housing cover 20.
A timer cam wheel 56 is received in timer cavity 14 and has a stub shaft 58 journal Ed in an aperture formed in housing wall 18 and spaced from the center of rotation of shaft 48. Wheel 56 also has a shaft 60 extending therefrom in direction opposite stub shaft 58 and through an aperture in housing cover 20. Shaft 60 is adapted for manual rotation by the appliance operator for suitable cycle program selection. In the presently preferred practice wheel 56 has a plurality of peripheral cam tracks 61, 64 and 66 provided thereon and has concentric therewith and axially adjacent a toothed ratchet surface 68 provided about the periphery thereof.
A second ratchet wheel 70 is received over shaft 60 for free rotation with respect to wheel 56 and wheel 70 also has a toothed ratchet surface 72 provided about the periphery thereof.
~L~2~63~
g Eccentric 52 has one end of a drive paw 74 received there over for reciprocal (orbital) movement thereof upon rotation of shaft 48. The free end of paw 74 has a ratchet engaging tooth 76 provided thereon which tooth is sufficient in width to engage both ratchet 68 and ratchet 72.
Referring in particular to Figure 1, the teeth of ratchet 72 has a pitch diameter slightly larger than ratchet 68. In the presently preferred practice ratchet 72 intermittently contains a deep notch 78 at a desired interval, or multiple of teeth, such that upon the paw tooth 76 engaging the deep notch, paw 74 drops to a position whereupon the ratchet tooth 76 engages simultaneous lye ratchet 72 and ratchet 68 to thereby index both ratchet wheels together for a single stroke. Thus, the single paw 74 provides continuous indexing of wheel 70 and intermittent indexing of wheel 56, dependent upon the number and spacing of deep notches provided in ratchet 72.
With continuing reference to Figure 1, gear box output shaft 48 rotates about a center of rotation nay and eccentric 52 is eccentric to point "An. In the presently preferred practice, the eccentric drive surface 52 is formed by a circular surface on shaft 48 having a center of rotation I displaced from shaft center "A" by an amount equal to the dimension "By. The indexing mechanism thus yields a longitudinal stroke for paw 74 equal to twice the amount of By In order for the drive paw 74 to function properly, irrespective of the direction of rotation of eccentric 52, it is necessary that the angle of contact of Z2963~
drive paw 74 with the ratchets 72, 68 be greater than a tangent angle to the ratchet at the point of contact of paw tooth 76. This is illustrated in Figure 1 wherein a line through the center of excursion "C" of eccentric 52 is shown to make an angle 0 with the tangent to the ratchet at the point of contact of paw tooth 76.
In order to prevent paw tooth 76 from disengaging or kicking out" of the teeth of the ratchet, for all positions of center of excursion I of eccentric 52, it is necessary that the angle 0 be approximately 10 degrees or greater. This means that for all positions of center of excursion "C" as eccentric 52 rotates either clockwise or counterclockwise, a line through center "C"
and the point of contact of paw tooth 76 with the ratchet must make an angle of at least 100 degrees with a radius to the ratchet at the point of tooth contact. The "bite"
of paw tooth 76 is maximized when the driving stroke occurs with center of excursion "C" of eccentric 52 above the center of rotation AYE of shaft 48, as viewed in Figure 1.
The arrangement for the indexing mechanism shown in Figure 1 gives the paw tooth 76 sufficient "bite" on the ratchet teeth to prevent malfunction of paw 74 in the event of counterclockwise rotation of eccentric 52, it being understood that in normal operation eccentric 52 rotates in a clockwise direction as viewed in Figure 1 in order to maximize the "bite" of the paw tooth 76.
Referring now to Figures 1 and 2, an anti reverse paw having hub 80 is pivotal received over a mounting post 82 extending from the wall 18 of the timer housing.
Paw 80 has a pair of generally parallel spaced fingers ;39 84, 86 extending from the hub thereof with paw 84 contacting a larger diameter ratchet 72 and finger 86 contacting smaller ratchet 68 such that any attempt to rotate the ratchets counterclockwise as shown in Figure 1 would be resisted by the "bite of the fingers 84, 86 sufficient to prevent counterclockwise rotation of the ratchet Paw 80 has a third finger 88 formed integrally with the hub 80 and extending rightwardly in Figure 1 which registers against a shouldered portion 90 provided integrally in the housing wall 18. In the presently preferred practice, the paw finger 88 is formed of resilient material such that it comprises a spring reloaded against lug 90 to provide torque on paw hub 80 to thereby bias the paw fingers 84, 86 into contact with ratchets 68, 72. It will be understood however to those skilled in the art that although paw finger 88 is formed of rigid material in the embodiment described, fingers 84, 86 may alternatively be formed of resilient material to thereby provide a reload of the fingers against the ratchet teeth.
Alternatively, as will hereinafter be described, anti reverse paw 80 may be pivotal mounted about the center of rotation "A" of drive shaft 48 to give the anti reverse paw and the main drive paw 74 a common reference point for attacking the ratchet teeth.
Functionally, this alternate arrangement facilitates varying the stroke of the advance paw 74 and yet permits the anti reverse paw to properly engage the ratchet teeth irrespective of the stroke of the advance paw.
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Referring again to Figure 1, the slower or main ratchet 68 can optionally have a raised tooth portion 92 having the same tooth pitch and pitch diameter as the teeth of ratchet 72 such that, at a selected position on the program cam wheel 56, the drive paw tooth 76 engages raised tooth 92 to provide a single one-step advance of the wheel 56 at a position separate from the deep notches 78.
Referring now to Figures 1, 3 and 4, the main or slow ratchet wheel 56 has the cam track 61 thereof engaged by a cam follower 94 having a cam engaging tooth 96 and being pivotal mounted about a post 98 extending upwardly from the wall 18 of the timer housing. Track 62 of the cam wheel 56 is engaged by cam follower 100 having a cam engaging tooth 102 with the follower 100 pivoted about post 82 (see also Fig. 2). Cam track 64 is engaged by tooth 104 provided in cam follower 106 pivotal received over post 980 Cam track 66 is engaged by tooth 108 of cam follower 110 which is pivotal mounted about post 82 tree Fig. 2).
Cam follower 94 has formed integrally therewith a lug 112 operative to contact for movement an electrical switch contact arm 114 having a movable contact 116 provided thereon for alternately making and breaking a circuit with stationary contacts 118, 120.
Cam follower 100 has a lug 122 extending integrally therefrom which Contacts a movable electrical switch arm 124 having a movable contact 126 provided thereon. Lug 122 is operative upon movement of the follower 100 to move contact 126 alternately between stationary contacts 128, 130 for` making and breaking 963~
electrical contact there between as desired for the appliance cycle program.
Cam follower 106 has a lug 132 extending integrally therefrom which upon motion of follower 106 contacts a movable contact arm 134 having a movable contact 136 provided thereon for making and breaking electrical contact wit a stationary contact 138.
Cam follower 110 has an integral lug 140 extending therefrom operative to contact a movable switch arm 142 having a movable contact 144 provided thereon for making and breaking an electrical circuit with stationary contact 146.
The programmer/timer of the present invention thus provides in the embodiment of Figures 1 and 4 a fast and slow ratchet operative to drive a main cam wheel 56 and a secondary cam surface 70 (see Fig. 4) attached to the fast ratchet 72. In the embodiment of Figure 1, cam follower tooth 102 on cam follower 100 has sufficient width to ride the track of cam 70 on the fast ratchet wheel so as to be responsive to notches thereon for permitting contact of movable electrical contact 126 with stationary contact 130 as required by the appliance cycle program.
To will be understood to those skilled in the art however, that as between cam track 70 and cam track 62, the sequence of events and positioning contact 126 by contact of the cam follower lug 122 with arm 124 may vary as desired to provide numerous combinations. For example, movable contact 126 may generally be positioned intermediate contacts 128 and 130 by cam track 62 and it operative thereby to intermediately make contact with stationary contact 130; and, responsive to cam track 70 on the fast ratchet wheel to make contact with contact 128 or to periodically make a circuit with stationary contact 130.
Alternatively, cam track 70 may be employed to make a circuit with stationary contact 130 and cam 62 may be employed only to make and break a circuit with contact 128. The particular choice of sequencing of contacts 126, 128 and 130 responsive to cam tracks 62 and 70 will be governed by the requirements of the program cycle of the particular appliance.
Referring now to Figure 5, an alternate embodiment, indicated generally at 10', of the timer of Figure 1 it shown wherein the shaft 48 about which eccentric: 52 rotates, has an auxiliary cam track 148 provided thereon for rotation with shaft 48 about point "A. A drive paw 150 has one end thereof received over eccentric 52 for orbital movement therewith and has a drive tooth 152 formed integrally therewith for engaging the ratchet on wheel 56. Pal 150 has formed integrally therewith a resilient spring member 154 which extends from the pivot center nay in a direction opposite of paw 150;
and, finger 154 is registered against a lug 156 provided integrally from housing wall 18. The finger 154 is reloaded by an amount to sufficient provide the necessary bias to maintain the drive paw tooth 152 in engagement with the ratchet.
cam follower 158 it pivotal mounted about a post 160 extend no from the housing wall 18. Cam follower 158 has a portion extending from post 160 in a direction ~2~3~
opposite the cam track 148 which portion has a lug 162 formed thereon for contacting the movable contact arm 124. In operation, as drive shaft 48 rotates, cam track 148 causes cam follower 158 to pivot which in turn causes lug 162 to move the contact 126 toward and away from stationary contact 130. The cam track 148 thus operates as a sub interval cam for movement of the movable electrical contact 1~6 with respect to the main interval operation of contact 126 by cam follower lug 122.
Referring now to Figure 6, another alternate arrangement of the timer of Figure 1 is indicated generally at 10" wherein a main drive paw 164 is pivotal received over eccentric 52 which is driven by shaft 48 by rotation about pivot center "A" for orbital movement of the paw 164. Integral drive tooth 166 on paw 164 contacts the ratchet on wheel 56 for causing indexed movement thereon. Shalt 48 also has auxiliary cam 148 provided thereon for movement of cam follower 158 for effecting subinter~al movement of contact 126 in similar fashion to the embodiment of Figure 5.
In the embodiment of Figure 6, the main drive paw 164 preferably has an integral spring finger 168 extending outwardly from the end of drive paw 164 containing ratchet contacting tooth 166. spring finger 168 is registered against a stationary lug 170 extending from the wall 118 of the timer housing. The spring finger 168 is reloaded by a desired amount to provide suitable bias of the paw tooth 166 into contact with the ratchet wheel.
Referring again to Figure 1, a still further alternate embodiment of the stepping mechanism of the Lowe present invention is illustrated wherein the drive paw 74 has an arm portion 172 extending therefrom in a direction angularly spaced from arm 74 with one end of a reload spring 174 connected thereto. The opposite end of spring 174 is anchored to a stationary post 176 extending from the wall 18 of the timer housing such that spring 174 is tensioned to provide a reload of paw arm tooth 76 against the ratchet on wheel 56.
Referring now to Figures 7, B and 9, an optional buzzer is illustrated as formed integrally with the motor stators plates in the timer construction of the present invention.
As illustrated in Figure 7 the outer stators plate 26 has formed integrally with one edge thereof an anvil 176; and, as shown in Figure 8 a striker arm 178 is formed integrally with one edge of the opposite stators plate 24, with the striker 176 extending in the free position in spaced parallel arrangement with striker 178.
The striker arm 178 has a cam follower portion 180 formed preferably integrally therewith and extending therefrom through an aperture 182 formed in the wall 18 of the timer housing. The cam follower portion 180 makes contact with one of the cam tracks on main cam wheel 56 as for example, cam track 66.
In operation, when the cam track 66 releases cam follower 180 from a position biased away from anvil 176, the alternating current excitation of the magnetic yield in Syria plates 24, 26 causes the striker arm 178 to vibrate against anvil 176 thereby giving an audible alarm.
~zc~3g Referring now to Figure 10, an alternate embodiment of the timer of Figure 1 is indicated generally at 190 as having a unitary housing 192 having a deep-well configuration with wall 194 about the periphery thereof and open to one side. Motor plates 24, 26 are received therein in spaced parallel arrangement, with the rotor assembly indicated generally at 36 and coil assembly indicated generally at 34 received therebetwèen with the stators plates received over posts shown typically at 193 and retained thereon by clips 32.
In the embodiment of Figure 10, the gear train indicated generally at 196 is assembled into the housing 192 from the opened side thereof, the motor stators plates, rotor and coil are assembled therein and the fast ratchet wheel 197 and slow or ratchet and wheel 195 containing the four main cam tracks are then assembled into the housing in side-by-side arrangement with the motor stators plates as shown in Figure 10.
The escapement mechanism and contact arms are also assembled into the housing 192 from the open side thereof and a cover plate 198 is then secured there over.
referring now to Figures 10 and 11, the main cam wheel has a plurality of rotating wiper arms 200 secured thereto by suitable fasteners such as rivets 202 and the wiper arms contact a stationary printed circuit board 204 secured to the inside of cover plate 198. Thus the embodiment of Figure 10 employs additional switching functions on the same cam wheel by incorporating rotating wipers for switching between contacts provided on a stationary printed circuit board. It will be understood however that alternatively, the printed circuit board 204 9~3~31 may be secured to the rotating cam wheel l9S and the wipers 200 may be secured in a stationary manner to the inside of housing cover plate 198.
Referring now to Figures 10, I and 13, the push-to-start feature of the timer 190 is illustrated wherein the main shaft 206 for cam wheel 195 may be pushed axially by the appliance operator from the position shown in solid outline in Figures 10 and 13 to the position shown therein in dashed outline. The shaft 206 has a circular cam surface 208 provided thereon adjacent the end nearest the wall 192 of the housing and a slid able cam follower 210 is engaged by the cam surface 208. A movable contact arm 212 having a movable electrical contact 214 thereon registers against cam follower 210 and has the stationary end thereof connected to an electrical connecting terminal 216 which extends to the exterior of the housing.
A stationary electrical contact 218 is attached to one end of an electrical collecting terminal 220 which also extends through the wall 192 of the housing for external attachment thereto. In operation, as the shaft 206 is moved axially by the operator to the position indicated in dashed outline, cam surface 208 moves follower 210 which causes arm 212 to move stationary contact 214 to make electrical connection with contact 218 Jo complete the circuit to the power source for energizing machine operation.
By pushing the shaft 206 tube appliance operator can complete the line power circuit irrespective of the position of the rotary cam wheel 195. Thus, the timer motor may be energized irrespective of the position of the ~963~
electrical switching contacts associated with the cam wheel 195 and the cam wheel 197.
The embodiment of Figure 10 permits assembly of the motor, gear train, stepping mechanism, rotary cams and ratchet wheels and cam followers and contacts all from one side of the timer housing without reversing the position of the timer housing during assembly. The additional advantage of the embodiment of Figure 10 is that the gear train 196 may be assembled in the housing without the power output shaft thereof extending through the wall of the housing. The embodiment of Figure 10 also eliminates the need for journaling one end of the output shaft in the cover of the timer housing as is the case in the embodiment of Figure 4.
Referring now to Figure 14, the arrangement of a typical contact arm with integral electrical connecting terminals is shown, wherein a an arm portion 222 see Fig.
1) has a folded double thickness portion 224 provided thereon and extending at right angles from portion 222.
The folded portion 224 extends through an aperture 226 provided in the wall 18 of the housing and is adapted for external electrical connection thereto. The folded portion 22~ of the arm 222 is received in a slot form by spaced guide surfaces 228, 230 formed integrally with a raised portion indicated generally at 232 provided in the timer housing. The arrangement of Figure 14 thus provides a unitary electrical connecting terminal and contact arm arrangement which is retained by simple sliding engagement with guide surfaces formed in the timer housing.
Referring now to Figure 15, an alternate arrangement of the embodiment of Figure 1 of the invention 1~29~39 is shown wherein the anti reverse member 222 is received on shaft 48 for pivotal movement about the center of rotation 'AYE of shaft I Member 22~ has a paw finger 224 which engages the ratchet 68 for preventing reverse rotation thereof by the appliance operator. Member 222 preferably has a resilient spring finger 226 provided integrally therewith which spring finger is registered against a lug 228 extending from the wall 18 of the housing. The spring finger 226 is reloaded to bias the paw 224 into engagement with the ratchet 68. The arrangement of Figure thus provides a common pivot reference for the main drive paw and the anti reverse member.
The present invention thus provides a unique appliance programmer-timer having a motor and cam driven electrical switching mechanism assembled in a unitary housing. The programmer-timer of the present invention employs a stepping mechanism for advancing the electrical switching cams. The stepping mechanism employs an eccentric-driven advancement paw for indexing a ratchet wherein the advancement paw will accommodate reverse rotation of the driving eccentric without malfunction of the advance mechanism. The timer of the present invention employs a unique anti reverse ratchet paw having an integral bias spring for preventing reverse rotation of the programming cam by the appliance operator. Optional features of the programmer-timer of the present invention include an auxiliary sub interval cam provided on the shaft driving the eccentric for the advance paw and an optional buzzer having a striker and anvil formed integrally with the motor stators plates. The present invention employs an optional drive paw having integral bias spring finger formed therewith. An optional rotating printed circuit board-wiper arrangement is provided for the cam wheels for additional switching functions.
~9639 -21- .
Although the invention has hereinabove been described in the presently preferred practice, it will be understood by those having skill in the art, that the invention is capable of modifications and variations all of which are deemed to be encompassed by the invention as defined by the following claims.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A device for electrical switching in timed sequence comprising (a) a primary and secondary cam means rotatably mounted on a housing about respectively first and second spaced centers of rotation;
(b) electrical switch means including primary cam follower means responsive to movement of said primary cam means for effecting electrical switching of contacts in accordance with a first program sequence;
(c) secondary cam follower means responsive to said secon-dary cam means for altering said electrical switching in accor-dance with a second program sequence;
(d) ratchet and pawl means operative to cause rotation of said primary cam means and including a ratchet wheel rotatable about said first center and a drive pawl orbital about said second center; and (e) drive means rotatable about said second center to cause said pawl to index said ratchet.
(b) electrical switch means including primary cam follower means responsive to movement of said primary cam means for effecting electrical switching of contacts in accordance with a first program sequence;
(c) secondary cam follower means responsive to said secon-dary cam means for altering said electrical switching in accor-dance with a second program sequence;
(d) ratchet and pawl means operative to cause rotation of said primary cam means and including a ratchet wheel rotatable about said first center and a drive pawl orbital about said second center; and (e) drive means rotatable about said second center to cause said pawl to index said ratchet.
2. A device for switching in timed sequence comprising:
(a) primary cam means including a ratchet wheel rotatably mounted on a housing;
(b) primary cam follower means responsive to movement of said cam means and operative for effecting movement of one of a first set of electrical contacts;
(c) drive means for advancing said cam means, said drive means including:
(i) a drive pawl pivotally mounted on said housing about a point spaced from the center of rotation of said cam means, said pawl contacting said ratchet wheel;
(ii) eccentric means rotatable for driving said pawl;
(iii) sub-interval cam means mounted on said housing means for rotation about a common center with said eccentric means;
(iv) motor means operative to rotate said sub-interval cam means and said eccentric means for effecting movement of said pawl for advancing said ratchet wheel;
(d) secondary cam follower means operative in response to rotation of said sub-interval cam means to effect sub-interval movement of one of said set of electricl contacts.
(a) primary cam means including a ratchet wheel rotatably mounted on a housing;
(b) primary cam follower means responsive to movement of said cam means and operative for effecting movement of one of a first set of electrical contacts;
(c) drive means for advancing said cam means, said drive means including:
(i) a drive pawl pivotally mounted on said housing about a point spaced from the center of rotation of said cam means, said pawl contacting said ratchet wheel;
(ii) eccentric means rotatable for driving said pawl;
(iii) sub-interval cam means mounted on said housing means for rotation about a common center with said eccentric means;
(iv) motor means operative to rotate said sub-interval cam means and said eccentric means for effecting movement of said pawl for advancing said ratchet wheel;
(d) secondary cam follower means operative in response to rotation of said sub-interval cam means to effect sub-interval movement of one of said set of electricl contacts.
3. The device defined in claim 2, wherein:
(a) said primary cam follower means is operative to effect movement of one of a first set of electrical contacts; and (b) said secondary cam follower means is operative to effect movement of one of a second set of electrical contacts.
(a) said primary cam follower means is operative to effect movement of one of a first set of electrical contacts; and (b) said secondary cam follower means is operative to effect movement of one of a second set of electrical contacts.
4. The device defined in claim 2, wherein, said secondary cam follower means is operative to effect sub-interval opening and closing of said set of contacts and said primary cam follower means is operative to prevent movement of said contacts by said sub-interval cam follower means during a primary interval.
5. The device defined in claim 1, wherein said pawl makes an angle less than ten (10) degrees above the tangent to the ratchet point of contact by the pawl.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/367,867 US4577179A (en) | 1982-04-15 | 1982-04-15 | Programmer/timer for appliances |
| US367,867 | 1982-04-15 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1229639A true CA1229639A (en) | 1987-11-24 |
Family
ID=23448965
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000425870A Expired CA1229639A (en) | 1982-04-15 | 1983-04-14 | Programmer/timer for appliances |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4577179A (en) |
| EP (1) | EP0092374B1 (en) |
| CA (1) | CA1229639A (en) |
| DE (1) | DE3379005D1 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4678930A (en) * | 1986-02-05 | 1987-07-07 | Eaton Corporation | Microwave oven timer |
| US4755635A (en) * | 1987-05-29 | 1988-07-05 | Eaton Corporation | Electrical programmer |
| US5042311A (en) * | 1988-06-06 | 1991-08-27 | Eaton Corporation | Secondary timer for program timer |
| FR2677805B1 (en) * | 1991-06-14 | 1993-09-17 | Sextant Avionique | SWITCHING DEVICE FOR ELECTRODOMESTIC APPARATUS PROGRAMMER. |
| BR9504997A (en) * | 1995-11-23 | 1997-03-04 | Elsys Equipamentos De Seguranc | Timer |
| US5736699A (en) * | 1996-05-03 | 1998-04-07 | Eaton Corporation | Elecro-mechanical programmer/timer |
| US5889244A (en) * | 1997-04-10 | 1999-03-30 | General Electric Company | Dishwasher sequence switch unit |
| US6486416B2 (en) | 1997-10-10 | 2002-11-26 | Emerson Electric Co. | Appliance timer having an auxiliary switching assembly |
| US5929403A (en) * | 1997-11-25 | 1999-07-27 | Emerson Electric Co. | Appliance timer having a maskable double throw subinterval mechanism |
| US6797897B2 (en) * | 1999-08-02 | 2004-09-28 | France/Scott Fetzer Company | Timer |
| ES2160554B1 (en) * | 2000-04-19 | 2002-09-01 | Fagor S Coop | ELECTRONIC PROGRAM SELECTOR FOR A WASHER. |
| US6844513B2 (en) | 2001-12-21 | 2005-01-18 | Emerson Electric Co. | Appliance timer |
| TWM256434U (en) * | 2004-03-05 | 2005-02-01 | Nien Made Entpr Co Ltd | Curtain Venetian blinds |
| US8119941B2 (en) * | 2006-07-21 | 2012-02-21 | Nidec Motor Corporation | Appliance timer |
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| US3650157A (en) * | 1959-03-16 | 1972-03-21 | Controls Co Of America | Timer |
| US3033999A (en) * | 1959-03-16 | 1962-05-08 | Controls Co Of America | Timer and timer positioning means |
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| NL294083A (en) * | 1962-06-16 | |||
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| US3262110A (en) * | 1963-08-12 | 1966-07-19 | Int Register Co | Electric timer provided with buzzer construction |
| US3248867A (en) * | 1963-11-07 | 1966-05-03 | Sunbeam Corp | Clock motor and movement |
| US3395585A (en) * | 1965-10-24 | 1968-08-06 | Controls Co Of America | Timer indexing mechanism |
| US3440813A (en) * | 1967-04-28 | 1969-04-29 | Gen Time Corp | Electromagnetic vibrator |
| US3540029A (en) * | 1967-12-14 | 1970-11-10 | Intern Register Co | Appliance timer with buzzer control |
| FR1565107A (en) * | 1968-01-19 | 1969-04-25 | ||
| DE1710541B2 (en) * | 1968-03-09 | 1972-08-03 | Holzer Patent Ag, Zug (Schweiz) | CONTROL FOR AUTOMATIC WASHING MACHINES AND THE LIKE |
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| US3664198A (en) * | 1970-06-29 | 1972-05-23 | Mallory & Co Inc P R | Drive means with variable outputs |
| DE2040464C3 (en) * | 1970-08-14 | 1980-05-14 | Ako-Werke Gmbh & Co, 7988 Wangen | Program controller for washing machines |
| US3737598A (en) * | 1971-03-04 | 1973-06-05 | Rythm Watch Co Ltd | Timing switch mechanism with manual adjustable cam |
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| GB1468863A (en) * | 1974-08-09 | 1977-03-30 | ||
| US3914951A (en) * | 1974-08-14 | 1975-10-28 | Gen Motors Corp | Defrost timer for indicating refrigerator warranty |
| US4179945A (en) * | 1978-09-05 | 1979-12-25 | The Singer Company | Variable step size impulse drive |
| US4250420A (en) * | 1979-06-05 | 1981-02-10 | Emhart Industries, Inc. | Sandwich structure for a combination motor and gear train with a timing mechanism |
| US4467664A (en) * | 1981-09-28 | 1984-08-28 | The Singer Company | Timer drive mechanism |
-
1982
- 1982-04-15 US US06/367,867 patent/US4577179A/en not_active Expired - Fee Related
-
1983
- 1983-04-13 DE DE8383302089T patent/DE3379005D1/en not_active Expired
- 1983-04-13 EP EP83302089A patent/EP0092374B1/en not_active Expired
- 1983-04-14 CA CA000425870A patent/CA1229639A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0092374A3 (en) | 1985-12-18 |
| US4577179A (en) | 1986-03-18 |
| DE3379005D1 (en) | 1989-02-23 |
| EP0092374A2 (en) | 1983-10-26 |
| EP0092374B1 (en) | 1989-01-18 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |