CA1217548A - Trigger switch circuit for solenoid-actuated electric hand tool - Google Patents
Trigger switch circuit for solenoid-actuated electric hand toolInfo
- Publication number
- CA1217548A CA1217548A CA000469771A CA469771A CA1217548A CA 1217548 A CA1217548 A CA 1217548A CA 000469771 A CA000469771 A CA 000469771A CA 469771 A CA469771 A CA 469771A CA 1217548 A CA1217548 A CA 1217548A
- Authority
- CA
- Canada
- Prior art keywords
- switch
- trigger
- circuit
- actuated
- trigger switch
- 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
- 230000007797 corrosion Effects 0.000 claims abstract description 11
- 238000005260 corrosion Methods 0.000 claims abstract description 11
- 230000007246 mechanism Effects 0.000 claims description 8
- 230000006872 improvement Effects 0.000 claims description 2
- 229910000881 Cu alloy Inorganic materials 0.000 abstract description 2
- 230000004044 response Effects 0.000 abstract description 2
- 241000282320 Panthera leo Species 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 230000001960 triggered effect Effects 0.000 description 2
- 238000010626 work up procedure Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- -1 wall board Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/72—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region
- H03K17/73—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region for dc voltages or currents
- H03K17/731—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region for dc voltages or currents with inductive load
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/02—Bases, casings, or covers
- H01H9/06—Casing of switch constituted by a handle serving a purpose other than the actuation of the switch, e.g. by the handle of a vacuum cleaner
Landscapes
- Portable Nailing Machines And Staplers (AREA)
- Push-Button Switches (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An electrically powered hand tool, such as a staple gun, can employ an electrical driver, such as a solenoid, which is actuated by a trigger circuit in response to depres-sion of a trigger on the handle of the device. The trigger circuit can include a circuit board dimensioned to fit into the handle of the staple gun, and having AC input leads. A
circuit formed of conventional electronic components delivers a burst of power to output leads which are in turn connected to a driver solenoid. This circuit is actuated to deliver the power burst by opening of a switch formed of two switch members:
one switch member has a first flexible resilient conductive leaf formed, e.g., of an alloy of copper, extending beyond an edge of the board; the other member has a flexible resilient leaf with a bent-in pointed end contacting a side of the first blade. These blades are biased against each other to form a normally-closed switch. When the first blade is moved in one direction, the switch opens. When the first blade returns in the other direction to close the switch, the pointed end of the other resilient leaf or blade scratches off corrosion at the contact area of the two members. This permits low current (1 ma) to be used as a control current through the switch.
An electrically powered hand tool, such as a staple gun, can employ an electrical driver, such as a solenoid, which is actuated by a trigger circuit in response to depres-sion of a trigger on the handle of the device. The trigger circuit can include a circuit board dimensioned to fit into the handle of the staple gun, and having AC input leads. A
circuit formed of conventional electronic components delivers a burst of power to output leads which are in turn connected to a driver solenoid. This circuit is actuated to deliver the power burst by opening of a switch formed of two switch members:
one switch member has a first flexible resilient conductive leaf formed, e.g., of an alloy of copper, extending beyond an edge of the board; the other member has a flexible resilient leaf with a bent-in pointed end contacting a side of the first blade. These blades are biased against each other to form a normally-closed switch. When the first blade is moved in one direction, the switch opens. When the first blade returns in the other direction to close the switch, the pointed end of the other resilient leaf or blade scratches off corrosion at the contact area of the two members. This permits low current (1 ma) to be used as a control current through the switch.
Description
7~;48 This invention relates to -trigger switch mechanisms for electrical apparatus, especially electrical hand tools, such as electric staple guns. More specifically, this invent lion is directed to a trigger switch mechanism for use in an electronically-controlled electric hand tool.
In state-of-the-art and previous electric staple guns, and in other similar electric hand tools, a micro switch is actuated by the hand tool's trigger to close or open in response to depression or release of the trigger.
O In the case of an electric stapler, it is conventional to use this micro switch to control the burst of power supplied to the driving solenoid of the stapler. For each depression of the manual trigger, the stapler delivers or "shoots" a single staple and drives the same into wood, wall board, fabric, or other workups. Normally, an electronic circuit, based on the silicon controlled rectifier (SIR) is employed and a small control current is fed through the micro switch to control the rather large burst of power that is delivered to the solenoid.
In the conventional electric staple gun circuit, the JO micro switch is of the normally open type, and the shot of power is delivered by the electronic circuit upon closing of the micro switch. Normally/ the working current or control current passing through the micro switch is on the order of only a few milliamps, perhaps even less than one milliamp.
These micro switches are susceptible to moisture problems, and can wear out or corrode after a period of use. If higher currents were used, the corrosion would not be a problem, as the current passing through the switch would "burn off" any corrosion. However, where low current is used, as it is here, the contacts in the micro switch do not remain clean.
~!~
Z175~8 As a result, in the conventional electric staple gun it is quite common that after only a few weeks or months corrosion in the switch will cause the trigger circuit to misoperate.
Accordingly, it is a principal object of this invent lion to avoid these problems of the prior art.
It is a more specific object of this invention to provide a trigger switch in which the problem of corrosion at low operating currents is avoided, because the corrosion is removed by mechanical actuation of the switch members.
O It is still another object of this invention to provide a trigger switch mechanism which is suitable to be used for actuation of an electric hand tool, and which can be configured as a normally closed, rather than normally open switch, so that the electronic circuitry for powering the sole-nod can be triggered much more reliably.
In accordance with an aspect of this invention, a trigger switch circuit is provided for an electric hand tool, such as a solenoid-driven power stapler, of the type having a casing, a manually actuated trigger situated in the casing, O and electric driving means, such as a solenoid, within the casing. The trigger switch circuit comprises input leads to be coupled to a source of AC power, a mechanical switch actual ted by the trigger, and electronic circuit means coupled to the input leads, to the switch, and to the electrical driving means for providing a burst of power to the latter when the switch is actuated by the trigger. The electronic circuitry provides a small control current through the switch to control the power burst to the solenoid.
With the improvement of this invention, the circuitry O is operative to be actuated by opening of the switch to deliver 1~:175g8 the power burst. Accordingly, the switch is formed of a first and a second conductive member, the first member having a first flexible resilient conductive leaf fixed at one end and extending at another free end thereof to be urged by the trig--~,~ ., germ The second member ho a second resilient conductive leaf fixed at one end and with Anton member at a free end thereof with a terminus (i.e., point) contacting a side of the first flexible resilient conductive leaf. With this arrangement, when the first conductive member is moved in one direction by actuation of the manual trigger, the switch opens, and when the trigger releases the first conductive member, the resin-fence of the first conductive leaf moves the latter in the opposite direction and brings the two members back into elect tribal contact to close the switch. The flexing of the first and second leaves moves the terminus of the bent-in member along the side of the first conductive leaf to scratch away corrosion thereon.
Preferably, the circuitry includes electronic come pennants mounted on a printed circuit board, and a first and second switch members are mounted at their fixed ends onto the printed circuit board, with at least the free end of the first flexible conductive leaf protruding beyond the edge of the printed circuit board.
The above and many objects, features, and advantages of this invention will be more fully understood from the en-suing detailed description of a preferred embodiment thereof, which is to be considered in connection with the accompanying drawings, in which Figure 1 is a perspective view of a power staple gun incorporating a trigger switch circuit embodying the present invention;
, ~2175g8 ' Figure 2 is a cross sectional view of the staple gun of Figure 1, showing a printed circuit board featuring the particular switch mechanism according to the embodiment of this invention;
Figures 3, and 4 are front and side elevation Al views, respectively, of the circuit board shown in Figure 2;
and Figure 5 is a schematic circuit diagram of the elect ironic circuitry of the preferred embodiment of this invention.
With reference to the drawings, and initially to Figure 1 thereof, a power staple gun 10 is shown to have a plastic housing assembly 12 including a drip portion 14 in which a finger-actuated trigger 16 is reposed, and a head 18 for housing a solenoid driver mechanism, to be described herein-after.
A staple magazine 20 is fastened to the housing 12, and a cord set 22 extends from one end of the grip portion 14.
A workman can pick up and manipulate the gun 10 by means of the grip portion 14, and depress the trigger 16 one finger. When the operator depresses the trigger 16, the sole-nod driver mechanism within the head 18 drives one staple S
out from the end of the magazine 20, as shown in Figure 1.
As is perhaps better shown in cross section in Figure 2, the staple gun 10 has an electromagnetic drive assembly 24, comprising an upper bumper 26, a plunger 28 to which is connected a flat knife 30, and a solenoid coil asset-by 32 for pulling the plunger 28 downward when current is applied thereto. A return spring 34 biases the plunger up-wards against the upper bumper 26.
A lower bumper 36 is held in a bumper retainer 38 do ' t' I, . .
lZ175~
serves to guide the path of the knife 30 and also limits the downward movement of the plunger 28. A knife backup plate 40, shown in ghost lines, guides the knife 30 to the top of a staple S situated at the end of the magazine 20, so that when the drive assembly 24 is actuated, the plate guides the knife 30, and the latter comes down sharply against the staple S to drive it from the magazine 20 into a workups.
Also shown within the grip portion 14 of the housing 12 is a solid-state trigger switch circuit 42 formed of elect tribal components situated on a printed circuit board 44.
A trigger switch assembly 46 is mounted on this board, and is actuated by an arm or protuberance 16' of the trigger 16.
As shown also in Figures 3 and 4, the circuitry on this board includes a pair of leads Lo and Lo connected to the cord set 22, and another pair of leads Lo and Lo coupled to the solenoid coil assembly 32. On the printed circuit board 44 there are also disposed conventional electronics components which are connected to the leads Ll-L4 and to the trigger switch 46. This circuitry provides a small control current to the latter, and provides a burst of power to the solenoid coil assembly 32 when the trigger switch 46 is opened.
The switch 46 is formed of first and second switch members 50 and 52, each having a spade portion at one end anchored onto the printed circuit board 44. The switch member 50 has a first flexible resilient conductive leaf or blade 54 formed, for example, ox a copper alloy, with a free end thereof extending over an edge of the printed circuit board 44 to be engaged by the trigger protuberance 16'. The other switch member 52 has a flexible resilient leaf or blade 56 5~8 with its free end arranged as a bent-in pointed member 58.
A sharp point on the pointed member 58 contacts a side of the blade or leaf 54. These leaves 54 and 56 are arranged goner-ally parallel to each other and biased against each other so that the switch 46 is normally closed.
When the lead 54 is moved in the direction of the arrow 60, by urging of the trigger protuberance 16', the switch 46 opens.
However, when the protuberance 16' releases the flexible blade or leaf 54, the resilience of the latter urges the flexible leaf 54 back against the bent-in pointed member 58 to close the switch.
The problem of corrosion at low operating current is avoided by operation of the blades or leaves 54 and 56. That is/ when these blades or leaves 54 and 56 flex closed upon movement in the direction opposite to the arrow 60, the point of the bent-in pointed member 58 moves along the surface of the side of the leaf or blade 54, so that the usual thin layer of corrosion is scratched away from the contact area of the leaf or blade 54.
Also, because the switch 46 is configured as a nor-molly closed, rather than normally open switch, the circuit 42 is triggered much more reliably.
In this embodiment, the printed circuit board 44 has one chamfered corner, to define one angled edge of the board 44. Preferably, the trigger switch 46 has at least the flex-isle leaf 54 extending over this angled edge of the printed circuit board 44.
A favorable embodiment of the circuit 42 is shown schematically in Figure 5. Here, leads Lo and Lo, which have white and black insulation, respectively, and which are ~17548 coupled to the cord set 22, are bridged by a voltage divider arrangement of resistors Al and R2, having nominal values, e.g., of 100 K and 5.6 K, respectively. The lead Lo is con-netted through a fuse Fly to the lead Lo, and thence to the solenoid assembly 32. The lead Lo is also connected through a resistor R3, having a nominal value of 180 K, to a integrated-circuit SIR driver circuit Us, and also to one terminal of the trigger switch 46/ another terminal of which is connected to the lead Lo. A low-voltage power supply is formed of a diode I Do coupled to the junction of the resistors Al and R2, and a capacitor Of, having a nominal value of 33 micro farads, and 10 volts working voltage. This arrangement provides a DC voltage of about 4.5 volts to a power supply terminal of the driver circuit Us. A ground terminal of the circuit Us is connected to the lead Lo.
A silicon controlled rectifier (SIR) Al has an anode connected through the lead Lo to the solenoid assembly I a cathode connected to the lead Lo, and a grate connected to a control output of the SIR driver circuit Us. A relaxation I circuit formed of a resistor R4, having a nominal value of 22 ohms, connected in series with a capacitor C2, having a nominal value of 0.1 micro farads, at 250 volts, bridges the anode and cathode of the SIR Al The SIR driver circuit Us actuates the SIR Al when the switch 46 is opened, so that the opening of the switch 36 results in the delivery of a burst of power, through the leads Lo and Lo, to the solenoid assembly 32.
While a trigger switch circuit for an electric hand tool has been described in detail hereinabove with reference to a single specific embodiment, it should be understood that the aye invention is not limited to that one embodiment, and that many modifications and variations thereof will become apparent to those of skill in the art without departure from the scope and spirit of this invention, as defined in the appended claims.
In state-of-the-art and previous electric staple guns, and in other similar electric hand tools, a micro switch is actuated by the hand tool's trigger to close or open in response to depression or release of the trigger.
O In the case of an electric stapler, it is conventional to use this micro switch to control the burst of power supplied to the driving solenoid of the stapler. For each depression of the manual trigger, the stapler delivers or "shoots" a single staple and drives the same into wood, wall board, fabric, or other workups. Normally, an electronic circuit, based on the silicon controlled rectifier (SIR) is employed and a small control current is fed through the micro switch to control the rather large burst of power that is delivered to the solenoid.
In the conventional electric staple gun circuit, the JO micro switch is of the normally open type, and the shot of power is delivered by the electronic circuit upon closing of the micro switch. Normally/ the working current or control current passing through the micro switch is on the order of only a few milliamps, perhaps even less than one milliamp.
These micro switches are susceptible to moisture problems, and can wear out or corrode after a period of use. If higher currents were used, the corrosion would not be a problem, as the current passing through the switch would "burn off" any corrosion. However, where low current is used, as it is here, the contacts in the micro switch do not remain clean.
~!~
Z175~8 As a result, in the conventional electric staple gun it is quite common that after only a few weeks or months corrosion in the switch will cause the trigger circuit to misoperate.
Accordingly, it is a principal object of this invent lion to avoid these problems of the prior art.
It is a more specific object of this invention to provide a trigger switch in which the problem of corrosion at low operating currents is avoided, because the corrosion is removed by mechanical actuation of the switch members.
O It is still another object of this invention to provide a trigger switch mechanism which is suitable to be used for actuation of an electric hand tool, and which can be configured as a normally closed, rather than normally open switch, so that the electronic circuitry for powering the sole-nod can be triggered much more reliably.
In accordance with an aspect of this invention, a trigger switch circuit is provided for an electric hand tool, such as a solenoid-driven power stapler, of the type having a casing, a manually actuated trigger situated in the casing, O and electric driving means, such as a solenoid, within the casing. The trigger switch circuit comprises input leads to be coupled to a source of AC power, a mechanical switch actual ted by the trigger, and electronic circuit means coupled to the input leads, to the switch, and to the electrical driving means for providing a burst of power to the latter when the switch is actuated by the trigger. The electronic circuitry provides a small control current through the switch to control the power burst to the solenoid.
With the improvement of this invention, the circuitry O is operative to be actuated by opening of the switch to deliver 1~:175g8 the power burst. Accordingly, the switch is formed of a first and a second conductive member, the first member having a first flexible resilient conductive leaf fixed at one end and extending at another free end thereof to be urged by the trig--~,~ ., germ The second member ho a second resilient conductive leaf fixed at one end and with Anton member at a free end thereof with a terminus (i.e., point) contacting a side of the first flexible resilient conductive leaf. With this arrangement, when the first conductive member is moved in one direction by actuation of the manual trigger, the switch opens, and when the trigger releases the first conductive member, the resin-fence of the first conductive leaf moves the latter in the opposite direction and brings the two members back into elect tribal contact to close the switch. The flexing of the first and second leaves moves the terminus of the bent-in member along the side of the first conductive leaf to scratch away corrosion thereon.
Preferably, the circuitry includes electronic come pennants mounted on a printed circuit board, and a first and second switch members are mounted at their fixed ends onto the printed circuit board, with at least the free end of the first flexible conductive leaf protruding beyond the edge of the printed circuit board.
The above and many objects, features, and advantages of this invention will be more fully understood from the en-suing detailed description of a preferred embodiment thereof, which is to be considered in connection with the accompanying drawings, in which Figure 1 is a perspective view of a power staple gun incorporating a trigger switch circuit embodying the present invention;
, ~2175g8 ' Figure 2 is a cross sectional view of the staple gun of Figure 1, showing a printed circuit board featuring the particular switch mechanism according to the embodiment of this invention;
Figures 3, and 4 are front and side elevation Al views, respectively, of the circuit board shown in Figure 2;
and Figure 5 is a schematic circuit diagram of the elect ironic circuitry of the preferred embodiment of this invention.
With reference to the drawings, and initially to Figure 1 thereof, a power staple gun 10 is shown to have a plastic housing assembly 12 including a drip portion 14 in which a finger-actuated trigger 16 is reposed, and a head 18 for housing a solenoid driver mechanism, to be described herein-after.
A staple magazine 20 is fastened to the housing 12, and a cord set 22 extends from one end of the grip portion 14.
A workman can pick up and manipulate the gun 10 by means of the grip portion 14, and depress the trigger 16 one finger. When the operator depresses the trigger 16, the sole-nod driver mechanism within the head 18 drives one staple S
out from the end of the magazine 20, as shown in Figure 1.
As is perhaps better shown in cross section in Figure 2, the staple gun 10 has an electromagnetic drive assembly 24, comprising an upper bumper 26, a plunger 28 to which is connected a flat knife 30, and a solenoid coil asset-by 32 for pulling the plunger 28 downward when current is applied thereto. A return spring 34 biases the plunger up-wards against the upper bumper 26.
A lower bumper 36 is held in a bumper retainer 38 do ' t' I, . .
lZ175~
serves to guide the path of the knife 30 and also limits the downward movement of the plunger 28. A knife backup plate 40, shown in ghost lines, guides the knife 30 to the top of a staple S situated at the end of the magazine 20, so that when the drive assembly 24 is actuated, the plate guides the knife 30, and the latter comes down sharply against the staple S to drive it from the magazine 20 into a workups.
Also shown within the grip portion 14 of the housing 12 is a solid-state trigger switch circuit 42 formed of elect tribal components situated on a printed circuit board 44.
A trigger switch assembly 46 is mounted on this board, and is actuated by an arm or protuberance 16' of the trigger 16.
As shown also in Figures 3 and 4, the circuitry on this board includes a pair of leads Lo and Lo connected to the cord set 22, and another pair of leads Lo and Lo coupled to the solenoid coil assembly 32. On the printed circuit board 44 there are also disposed conventional electronics components which are connected to the leads Ll-L4 and to the trigger switch 46. This circuitry provides a small control current to the latter, and provides a burst of power to the solenoid coil assembly 32 when the trigger switch 46 is opened.
The switch 46 is formed of first and second switch members 50 and 52, each having a spade portion at one end anchored onto the printed circuit board 44. The switch member 50 has a first flexible resilient conductive leaf or blade 54 formed, for example, ox a copper alloy, with a free end thereof extending over an edge of the printed circuit board 44 to be engaged by the trigger protuberance 16'. The other switch member 52 has a flexible resilient leaf or blade 56 5~8 with its free end arranged as a bent-in pointed member 58.
A sharp point on the pointed member 58 contacts a side of the blade or leaf 54. These leaves 54 and 56 are arranged goner-ally parallel to each other and biased against each other so that the switch 46 is normally closed.
When the lead 54 is moved in the direction of the arrow 60, by urging of the trigger protuberance 16', the switch 46 opens.
However, when the protuberance 16' releases the flexible blade or leaf 54, the resilience of the latter urges the flexible leaf 54 back against the bent-in pointed member 58 to close the switch.
The problem of corrosion at low operating current is avoided by operation of the blades or leaves 54 and 56. That is/ when these blades or leaves 54 and 56 flex closed upon movement in the direction opposite to the arrow 60, the point of the bent-in pointed member 58 moves along the surface of the side of the leaf or blade 54, so that the usual thin layer of corrosion is scratched away from the contact area of the leaf or blade 54.
Also, because the switch 46 is configured as a nor-molly closed, rather than normally open switch, the circuit 42 is triggered much more reliably.
In this embodiment, the printed circuit board 44 has one chamfered corner, to define one angled edge of the board 44. Preferably, the trigger switch 46 has at least the flex-isle leaf 54 extending over this angled edge of the printed circuit board 44.
A favorable embodiment of the circuit 42 is shown schematically in Figure 5. Here, leads Lo and Lo, which have white and black insulation, respectively, and which are ~17548 coupled to the cord set 22, are bridged by a voltage divider arrangement of resistors Al and R2, having nominal values, e.g., of 100 K and 5.6 K, respectively. The lead Lo is con-netted through a fuse Fly to the lead Lo, and thence to the solenoid assembly 32. The lead Lo is also connected through a resistor R3, having a nominal value of 180 K, to a integrated-circuit SIR driver circuit Us, and also to one terminal of the trigger switch 46/ another terminal of which is connected to the lead Lo. A low-voltage power supply is formed of a diode I Do coupled to the junction of the resistors Al and R2, and a capacitor Of, having a nominal value of 33 micro farads, and 10 volts working voltage. This arrangement provides a DC voltage of about 4.5 volts to a power supply terminal of the driver circuit Us. A ground terminal of the circuit Us is connected to the lead Lo.
A silicon controlled rectifier (SIR) Al has an anode connected through the lead Lo to the solenoid assembly I a cathode connected to the lead Lo, and a grate connected to a control output of the SIR driver circuit Us. A relaxation I circuit formed of a resistor R4, having a nominal value of 22 ohms, connected in series with a capacitor C2, having a nominal value of 0.1 micro farads, at 250 volts, bridges the anode and cathode of the SIR Al The SIR driver circuit Us actuates the SIR Al when the switch 46 is opened, so that the opening of the switch 36 results in the delivery of a burst of power, through the leads Lo and Lo, to the solenoid assembly 32.
While a trigger switch circuit for an electric hand tool has been described in detail hereinabove with reference to a single specific embodiment, it should be understood that the aye invention is not limited to that one embodiment, and that many modifications and variations thereof will become apparent to those of skill in the art without departure from the scope and spirit of this invention, as defined in the appended claims.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a trigger switch circuit for an electric hand tool of the type having a casing, a manually actuated trigger, and electrical driving means, the circuit comprising input leads to be coupled to a source of AC power, a mechanical switch actuated by said trigger, and electronic circuit means coupled to said input leads, said switch, and said electrical driving means for providing a burst of power to the latter when said switch is actuated by said trigger, the circuit means providing a small control current through said switch to control the power burst to said driving means; the improvement wherein said circuit means is operative to be actuated by open-ing of said switch to deliver said power burst; and said switch is formed of a first and a second conductive member, the first member having a first flexible resilient conductive leaf fixed at one end and extending at another, free end thereof to be urged by said trigger; said second member including a second resilient conductive leaf fixed at one end and having a bent-in member at a free end thereof with a terminus contacting a side of the first flexible resilient conductive leaf, whereby when the first conductive member is moved in one direction by actua-tion of said trigger, the switch opens, and when the trigger releases the first conductive member, the resilience of the first conductive leaf moves the latter in the opposite direction and brings the two members back into contact to close the switch, and the flexing of the first and second leaves moves the ter-minus of said bent-in member along the side of the first con-ductive leaf to scratch away corrosion thereon.
2. Trigger switch circuit according to claim 1, wherein said circuit means includes electronics components mounted on a printed circuit board, and said first and second switch members are mounted at said one ends thereof onto said printed circuit board.
3. Trigger switch circuit according to claim 2, wherein said first and second conductive leaves are disposed generally parallel to one another.
4. Trigger switch circuit according to claim 2, wherein said free end of said first flexible conductive leaf protrudes beyond an edge of said printed circuit board.
5. Trigger switch circuit according to claim 2, wherein said bent-in member has a point as its terminus, with said point being operative to scratch away corrosion from an area of contact between said first and second members.
6. Trigger switch circuit according to claim 1, wherein said circuit means provides a control current to said switch of not more than substantially five milliamps.
7. Trigger switch circuit according to claim 6, wherein said circuit means provides a control current of less than about one milliamp.
8. Trigger switch mechanism according to claim 1, where-in said electrical driving means includes a solenoid and asso-ciated plunger means.
9. Trigger switch mechanism according to claim 1, wherein said electric hand tool is an electric staple gun.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US58473584A | 1984-02-29 | 1984-02-29 | |
| US584,735 | 1984-02-29 | ||
| US06/600,398 US4556803A (en) | 1984-02-29 | 1984-04-16 | Trigger switch circuit for solenoid-actuated electric hand tool |
| US600,398 | 1984-04-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1217548A true CA1217548A (en) | 1987-02-03 |
Family
ID=27079188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000469771A Expired CA1217548A (en) | 1984-02-29 | 1984-12-11 | Trigger switch circuit for solenoid-actuated electric hand tool |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4556803A (en) |
| CA (1) | CA1217548A (en) |
| DE (1) | DE3436416C2 (en) |
| NL (1) | NL192158C (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4679719A (en) * | 1985-12-27 | 1987-07-14 | Senco Products, Inc. | Electronic control for a pneumatic fastener driving tool |
| DE4038786A1 (en) * | 1990-12-05 | 1992-06-11 | Bsg Schalttechnik | DEVICE FOR CONTROLLING OR REGULATING DEVICES SUPPLIED BY BATTERIES |
| CA2179524A1 (en) * | 1994-10-21 | 1996-05-02 | Charles J. Moorman | Pneumatic fastener driving tool and an electronic control system therefor |
| JP3287172B2 (en) * | 1995-04-05 | 2002-05-27 | マックス株式会社 | Nailer trigger device |
| US6012622A (en) * | 1998-04-20 | 2000-01-11 | Illinois Tool Works Inc. | Fastener driving tool for trim applications |
| EP1324861A1 (en) | 2000-08-25 | 2003-07-09 | Senco Products, Inc | Impact device |
| US7866521B2 (en) * | 2004-12-03 | 2011-01-11 | Black & Decker Inc. | Magazine for wired-collated fasteners with automatic loading |
| US7414337B2 (en) * | 2005-03-14 | 2008-08-19 | Black & Decker Inc. | Scrubber |
| US20060293711A1 (en) * | 2005-06-23 | 2006-12-28 | Activator Methods International, Ltd. | Portable chiropractic adjustor |
| US8225978B2 (en) | 2007-02-01 | 2012-07-24 | Black & Decker Inc. | Multistage solenoid fastening tool with decreased energy consumption and increased driving force |
| US7537145B2 (en) * | 2007-02-01 | 2009-05-26 | Black & Decker Inc. | Multistage solenoid fastening device |
| CN106825367B (en) * | 2016-12-30 | 2019-02-22 | 东莞产权交易中心 | A kind of cup-shaped hammper |
| EP3578306A1 (en) * | 2018-06-06 | 2019-12-11 | HILTI Aktiengesellschaft | Setting device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3346163A (en) * | 1965-10-22 | 1967-10-10 | Fed Tool Engineering Co | Automatic electric stapler |
| CH484503A (en) * | 1967-06-19 | 1970-01-15 | Polycontact Ag | Snap-action switch for switching low electrical voltages and / or currents |
| GB1294655A (en) * | 1968-10-21 | 1972-11-01 | Plessey Co Ltd | Improvements relating to electric ignition devices |
| US3589587A (en) * | 1969-04-16 | 1971-06-29 | Allan Finishing Corp | Electrically operated staplers |
| DE2226788C2 (en) * | 1971-08-20 | 1974-05-22 | Erwin Mueller Kg, Metallwarenfabrik, 4450 Lingen | Nailer with a driving ram driven by the armature of an electromagnet |
| JPS5761480A (en) * | 1980-09-26 | 1982-04-13 | Hitachi Koki Kk | Motor tool |
-
1984
- 1984-04-16 US US06/600,398 patent/US4556803A/en not_active Expired - Fee Related
- 1984-10-04 DE DE19843436416 patent/DE3436416C2/en not_active Expired - Fee Related
- 1984-10-16 NL NL8403155A patent/NL192158C/en not_active IP Right Cessation
- 1984-12-11 CA CA000469771A patent/CA1217548A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3436416C2 (en) | 1995-11-23 |
| NL8403155A (en) | 1985-09-16 |
| NL192158C (en) | 1997-02-04 |
| DE3436416A1 (en) | 1985-08-29 |
| US4556803A (en) | 1985-12-03 |
| NL192158B (en) | 1996-10-01 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |