US3700837A

US3700837A - Adjustable timer cam assembly spring biased by contacts for normal engagement with synchronous motor driven gear

Info

Publication number: US3700837A
Application number: US159615A
Authority: US
Inventors: Karl J Schulze-Berge
Original assignee: AMF Inc
Current assignee: Paragon Electric Co Inc
Priority date: 1971-07-06
Filing date: 1971-07-06
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24
Also published as: CA942363A

Abstract

A time switch having a rotor of unitary construction mounted at its ends in slots and having a meshed gear connection with drive means. Switch means providing a biasing force to said rotor for maintaining the meshed gear connection and said rotor being adapted for manual rotation relative to said drive means and against the biasing force causing its ends to move in said slots and said gears providing the drive connection to move out of mesh.

Description

United States Patent 151 3,700,837 Schulze-Berge 1 Oct. 24, 197 2 {54] ADJUSTABLE TIMER CAM ASSEMBLY [56] References Cited sPRING BIASED BY CONTACTS EoR NORMAL ENGAGEMENT WITH UNTED STATES PATENTS SYNCHRONOUS MOTOR DRIVEN 3,260,807 7/ 1966 Rulseh et al. ..200/ 38 FE GEAR 3,500,005 3/1970 Brown ..200/38 B lnventor: Karl J. Schulu-Berge, Manitowoc,

Wis.

Assignee: AMF Incorporated Filed: July 6, 1971 Appl. No.: 159,615

US. Cl. ..200/38 R, 200/1 A, ZOO/38 A, 200/38 BA Int. Cl. ..H0lh 43/10 Field of Search ..200/38, 17 R, 18, 166 J, l A

Primary Examiner-J. R. Scott Attorney-George W. Price et a].

[57] ABSTRACT A time switch having a rotor of unitary construction mounted at its ends in slots and having a meshed gear connection with drive means. Switch means providing a biasing force to said rotor for maintaining the meshed gear connection and said rotor being adapted for manual rotation relative to said drive means and against the biasing force causing its ends to move in said slots and said gears providing the drive connection to move out of mesh.

8 Claims, 3 Drawing Figures PATENTEU 24 I97? 3. 700 83 T [NVENTOR KARL J. .SCHULZEERGE AGENT ADJUSTABLE TIMER CAM ASSEMBLY SPRING BIASED BY CONTACTS FOR NORMAL ENGAGEMENT WITH SYNCHRONOUS MOTOR DRIVEN GEAR This invention relates generally to electric circuit controls and more specifically to a time switch therefor which has a fixed repetative cycle for timed opening and closing at least one pair of switch contacts.

Time switches of this general type, as shown in US. Pat. No. 3,391,258 granted to RR. Virnoche, .lr., and assigned to the same assignee as is the present application, are particularly adapted for use as refrigerator controls. It should be understood, however, there is no intent to limit the present invention to such a single envlronment.

The construction of this type of a time switch is relatively uncomplicated. A switch operating cam is provided with a gear which is driven by the output gear of a synchronous motor. In normal use, the time switch will startto operate when its motor is energized, and will continue to repetatively operate in accordance with its time cycle.

However, such time switches must be capable of being manually set which requires rotatably repositioning the cam. Since the type of synchronous motor used to drive the cam normally is provided with a high ratio step-down gear train, the motor output gear cannot be manually rotated and a one way clutch connection between the cam and its drive gear is therefore required. It has been found that this construction adds substantially to the cost of material and labor.

Accordingly, an object of the present invention is to provide an improved construction for time switches of the type described.

Another object of the present invention is to reduce the number of parts and to improve the reliability of the foregoing time switches.

' The present invention contemplates a time switch having a motor driven unitary rotor mounted at its ends in slots. The rotor has a switch means actuating cam and a drive gear releasably retained in mesh with a motor output gear by a spring bias provided by the switch means.

The foregoing and other objects and advantages will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompanying drawings wherein one embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only, and are not to be construed as defining the limits of the invention.

FIG. 1 is a elevational view of a time switch made in accordance with the present invention, with most of the cover broken away to expose the internal operating mechanism thereof;

FIG. 2 is a view similar to FIG. 1 with the terminal end of the time switch removed and the drive connection between the motor and rotor disengaged; and

FIG. 3 is an end elevational view of the time switch of FIG. 1 with a portion of the case broken away.

Referring now to the drawings, a time switch made in accordance with the present invention is provided with a case having a side wall 11 and a continuous peripheral wall or flange l3 defining a switch chamber with an open side closed by a cover 15. A portion 14 of the peripheral flange 13 at one end of the case 10 is of a slotted double wall configuration. The wall 11 and cover 15 are provided with axially aligned

slots

12 and 16, respectively, disposed toward the other end of the case 10 opposite from the double walled flange portion 14.

A synchronous motor 18 is mounted on the outside of the case 10 and has an output shaft and gear arrangement 19 which extends into the switch chamber through an opening in the wall 1 1.

The time switch is provided with switch means 20 comprising three spring contact arms 21, 22-and 23 each having a terminal end portion which extends through one of the slots of the double walled flange portion 14, and is supported thereby. A spacer 24 is provided at the other end of the switch means 20 to limit the minimum closure between the free contact ends of the two

outer arms

21 and 23. The common contact arm 22 is disposed between and is longer at its free contact end than the

arms

21 and 23.

The rotor 30 of the time switch has three distinct portions, namely, a single lobe cam 31 for actuating the switch means 20, a shaft 32 mounted at its ends in the

slots

12 and 16, and a gear 33 which meshes with the output gear 19 to provide a rotor driving connection. While the cam 31 and gear 33 may be made as separate parts and fixedly mounted on the shaft 32, the rotor 30 preferably may be molded as a single piece.

The mesh of

gears

19 and 33 and the contact area between the cam 31 and the spring contact blade 21 or

blades

21 and 22 are substantially diametrically opposite to one another or on opposite sides of the axis of the rotor 30. All of the

blades

21, 22 and 23 of the switch means 20 are always deflected out of their normal planes and exert a biasing force urging the gear 33 into mesh with gear 19 and the ends of the shaft 32 toward the upper ends of the

slots

12 and 16, as shown in FIG. 1.

Manual rotation of the rotor 30, in a clockwise direction as viewed in FIGS. 1 and 2, against a nonrotating or a slowly rotating motor output gear 19 urges the ends of the shaft 32 toward the other or lower ends of the

slots

12 and 16, against the bias of the spring means 20, causing the gear 33 to move out of mesh with the gear 19, as shown in FIG. 2. It should be noted that the

slots

12 and 16 must be sufficiently long so as not to limit the movement of the ends of the shaft 32.

It is preferred to have both shaft ends 32 movable in slots as is hereinbefore described. However, where the distance between the wall 11 and the cover 15 is sufficient to permit disengagement of the

gears

19 and 33 by cocking of the rotor 30, one of the

slots

12 or 16 may be merely a circular opening. Preferably in the present construction as shown in the drawings, the opening 12 in the wall 11 which is closer to the gear 33 would be elongated to form a slot while the opening 16 in the cover 15 would be circular.

Although but a single embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

I claim:

1. In a time switch, the combination comprising:

a pair of spaced wall portions each having an opening generally corresponding to the opening of the other wall portion;

at least one of said openings being elongated to form a slot;

a rotor disposed between said wall portions and having a drive gear, a cam, and shaft portions at its ends rotatably disposed in said openings;

drive means including an output gear in mesh with said drive gear for rotatably driving said rotor;

switch means engaging said cam on the side of said rotor opposite from said output gear and being actuated by said cam as it rotates;

said switch means providing a biasing force on said rotor urging said drive gear into mesh with said output gear and said shaft portions toward corresponding sides of said openings; and

said rotor being adapted to be manually rotated relative to said output gear and against the bias of said switch means causing one of said shaft portions to move along the length of said slot and said drive gear to move out of mesh with said output gear.

2. The time switch in accordance with claim 1, and

both of said openings being elongated to form slots thereby permitting both of said shaft portions to move along the lengths of said slots when said drive gear moves out of mesh with said output gear.

3. The time switch in accordance with claim 1, and

said switch means comprising:

a plurality of spring contact arms each having a supported terminal end and a free contact end; and

the free contact end of at least one of said spring contact arms engaging said cam and said arm being deflected out of its normal plane for providing the biasing force to said rotor.

5. The time switch in accordance with claim 4, and

all of said spring contact arms being deflected out of their normal planes for providing the biasing force to said rotor.

6. The time switch in accordance with claim 1, and

said rotor being of a unitary construction.

7. The time switch in accordance with claim 6, and

said switch means comprising:

8. The time switch in accordance with claim 7, and

Claims

1. In a time switch, the combination comprising: a pair of spaced wall portions each having an opening generally corresponding to the opening of the other wall portion; at least one of said openings being elongated to form a slot; a rotor disposed between said wall portions and having a drive gear, a cam, and shaft portions at its ends rotatably disposed in said openings; drive means including an output gear in mesh with said drive gear for rotatably driving said rotor; switch means engaging said cam on the side of said rotor opposite from said output gear and being actuated by said cam as it rotates; said switch means providing a biasing force on said rotor urging said drive gear into mesh with said output gear and said shaft portions toward corresponding sides of said openings; and said rotor being adapted to be manually rotated relative to said output gear and against the bias of said switch means causing one of said shaft portions to move along the length of said slot and said drive gear to move out of mesh with said output gear.

2. The time switch in accordance with claim 1, and both of said openings being elongated to form slots thereby permitting both of said shaft portions to move along the lengths of said slots when said drive gear moves out of mesh with said output gear.

3. The time switch in accordance with claim 1, and said cam and drive gear being fixedly mounted on said shaft portion of said rotor.

4. The time switch in accordance with claim 3, and said switch means comprising: a plurality of spring contact arms each having a supported terminal end and a free contact end; and the free contact end of at least one of said spring contact arms engaging said cam and said arm being deflected out of its normal plane for providing the biasing force to said rotor.

5. The time switch in accordance with claim 4, and all of said spring contact arms being deflected out of their normal planes for providing the biasing force to said rotor.

6. The time switch in accordance with claim 1, and said rotor being of a unitary construction.

7. The time switch in accordance with claim 6, and said switch means comprising: a plurality of spring contact arms each having a supported terminal end and a free contact end; and the free contact end of at least one of said spring contact arms engaging said cam and said arm being deflected out of its normal plane for providing the biasing force to said rotor.

8. The time switch in accordance with claim 7, and all of said spring contact arms being deflected out of their normal planes for providing the biasing force to said rotor.