US3410971A

US3410971A - Double throw, snap acting electric switch

Info

Publication number: US3410971A
Application number: US618033A
Authority: US
Inventors: Sandor Bela
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1967-02-23
Filing date: 1967-02-23
Publication date: 1968-11-12
Anticipated expiration: 1985-11-12

Description

Nov. 12, 1968 a. SANDOR DOUBLE THROW, SNAP ACTING ELECTRIC SWITCH Filed Feb. 23, 1967 1 \JVEN TOR 736/0 fawdor A 7'TOR/VEV United States Patent 3,410,971 DOUBLE THROW, SNAP ACTING ELECTRIC SWITCH Bela Sandor, Detroit, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 23, 1967, Ser. No. 618,033 3 Claims. (Cl. 200-67) ABSTRACT OF THE DISCLOSURE In a preferred form, the subject invention teaches a switch having a torsion spring centering means and a compression spring tending to separate a contact carrier from the actuator, the contact carrier having cam portions which serve to center the switch by virtue of the inclined portion of the cam engaging protruding fixed contacts in the switch body. When the actuator is pivoted, the contact carrier is driven along fixed contacts compressing the centering or compression spring with movable contacts carried by the contact carrier being snapped into engagement with the fixed contacts when the highest part of the cam is passed.

This invention relates to a double acting, snap action switch particularly adapted for use in the environment of an automobile acting as a window regulator switch therefor.

Window regulator switches of common design have strict operational requirements due to the environment in which they operate as Well as having very definite physical requirements in view of the high amperage load generally switched thereby. In addition, it is important that a .vehicle operator have a positive indication of when the switch is actuated in order to prevent overtravel of the switch actuator after the desired circuit is energized. The subject switch has a resilient member sealing the switching area of the switch from the elements thereby minimizing oxidation of the moving switch part due to exposure to the elements. A snap action is provided for contact engagement which has the dual purpose of very quickly switching high amperage circuits thereby minimizing material transfer of the contacts and, at the same time, positively indicating by feel to an operator that the switching has taken place.

It is an object of the present invention to provide an improved switch which is moisture-proof and which is adapted for operation as a power window regulator switch on a vehicle.

It is another object of the present invention to provide an improved electric switch which utilizes a cam formed on the contact carrier to give the switch a snap acting capability and which serves to positively center the contact carrier relative to fixed contacts under static conditions.

It is still another object of the present invention to provide an improved electric switch which utilizes a torsion spring for centering an actuator, said actuator including guide means engaging a free floating contact carrier to guarantee linear alignment between the contact carrier and the actuator, the actuator and the contact carrier being biased apart by a compression spring trapped therebetween.

Further objects and advantages of the present invention will be apparent from the following description, reference being bad to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIGURE 1 is a sectional view of the switch of the subject invention shown in a static position;

3,410,971 Patented Nov. 12, 1968 FIGURE 2 is a sectional view of the subject switch taken along line 2-2 of FIGURE 1;

FIGURE 3 is a sectional view of the subject switch in the plane of FIGURE 1 which illustrates the configuration of internal portions of the switch during a snap action movement of the contact carrier;

FIGURE 4 is a sectional view similar to that shown in FIGURE 3 which illustrates the interior portions of the subject switch in the configuration they assume when full contact of the switching contacts is realized;

FIGURE 5 is a perspective view of the actuator and contact carrier of the subject switch in interlocked disposition with the relative position of the parts being clearly illustrated.

Referring to FIGURE 1, an actuator 10 is disposed in opening 12 of switch body 14 and is pivotable about pivot pin 16. Pivot pin 16 is carried in a complementary shaped slot 18, better seen in FIGURE 2. Referring to FIGURE 1, switch body 14 has a plurality of walls, an outer wall 20 and an inner wall 22. It is clear from an examination of FIGURE 1 that inner wall 22 is shorter than outer wall 20 and outer wall 20 includes a curved extension 24. A plate 26 is snapped into operative disposition between an end of wall 22 and extension 24. No other fastening means are necessary.

The fixed contacts 28 are four in number and are symmetrically disposed in plate 26 relative to opening 12. Extensions 30 of fixed contacts 28 extend into compartment 32 which is sealed from opening 12 by resilient seal 34. Seal 34 resiliently engages the periphery of actuator 10 along surface 36 and includes beaded ends 38 trapped between portions of outer wall 20 and inner wall 22.

Contact carrier 40 carries contacts 42 which are spaced apart and electrically connected by conductor strip 44. Cam lobes 46 are formed near the lower edge of contact carrier 40, as viewed in FIGURE 1, and have an inclined surface engaging the inner edges of extension 30 of contacts 28. Compression spring 48 urges contact carrier 40 away from actuator 10 and serves to center contact carrier 40 between extensions 30. Torsion spring 50 is held against the underside of seal 34 by the urging of spring 48 acting through actuator 10.

Referring to FIGURE 5, the relative disposition of parts of contact carrier 40- and actuator 10 is clearly shown and it will be noted that extensions 52 of contact carrier 40 are slida'bly disposed between external projecting portions 54 of actuator 10. Therefore, contact carrier 40 is guided along a plane normal to the direction of pivotal movement of actuator 10 guaranteeing alignment of contacts 42 with the symmetrically disposed extensions 30 of contacts 28.

In operation, when it is desired to actuate electrical apparatus electrically connected to terminals or contacts 28, actuator 10 is pivoted either clockwise or counterclockwise around pivot pin '16, as viewed in FIGURE 1. For purposes of this explanation clockwise pivoting is chosen, it being understood that the operation of the subject switch is identical with the reverse pivoting of the actuator 10.

When actuator 10 is pivoted in a clockwise manner, the bottom edge of actuator 10 in the direction of rotation engages torsion spring 50 drawing one leg thereof from its seat against seal 34. At the same time, due to the interlocking of extensions 52 with projections 54, the contact carrier 40 follows the pivotal movement of actuator 10. As best seen in FIGURE 3, cam lobes 46 are driven up along the top edge of extension 30 compressing spring 48. When the highest point of cam lobe 46 is passed, there is sufficient relative movement possible between carrier 40 and actuator 10 to allow compression spring 48 to release its energy stored during the com pression and very quickly move contacts 42 toward extensions 30. With the snap action finally completed and the actuator in the extreme of movement, the switch parts assume a configuration as shown in FIGURE 4. It is understood that a pair of the contacts 28 on one side of the switch body are in one operative circuit that is controlled, for example, in an electric motor operating in one direction and the opposite pair of contacts 28 are disposed in another electrical circuit, such as the circuit allowing reverse rotation of a permanent magnet electric motor. Conductive strip 44, best seen in 'FIGURE 2, accomplishes the bridging between the spaced contacts 42 and the spaced extensions resulting in circuit continuity.

It is obivous that counterclockwise rotation of actuator 10 would accomplish a similar but opposite cycling of the subject switch with contact engagement coming in a similar fashion utilizing the other pair of extensions 30 resulting in a different electrical circuit being made continuous. It should also be noted that, as the contacts 42 are snapped into engagement with extensions 30, the contacts move from an initial contacting position illustrated in FIGURE 3 to a final rest position, as shown in FIGURE 4. A sliding of the contacts thereby takes place resulting in a wiping of the contacts and the cleaning of any oxidation that may have formed on the opposing surfaces. This, of course, guarantees good electrical conductivity after repeated operations over a long period. The snap action generated by the cooperation of compression spring 48 and the contact carrier allows a minimum of arcing in the energized circuit when the switch is operated in the environment of a vehicle window regulating system which may approach 30 amps.

While the embodiment of the present invention, as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is:

1. An electrical switch for use as a window regulator control in a motor vehicle, said switch comprising: a switch housing having a plurality of walls extending parallel to the longitudinal axis thereof, said plurality of walls being spaced apart with an inner wall being shorter than an outer wall with the outer wall having a portion projecting beyond the end of the inner wall; a plate snapped between said shorter inner wall and said extending portion of said outer wall to close one end of said switch body; actuator means having a plurality of outwardly extending pivot pins engaging complementary shaped depressions formed in the inner wall of said switch body to control pivotal movement of said actuator means, said actuator means substantially closing the end of said switch body opposite the end closed by said plate, a resilient sheet firmly engaging the outer periphery of said actuator means and interlocked between portions of said inner and outer wall of said switch body to elfectively seal the exterior of such switch from a compartment formed adjacent said plate; a torsion spring having ends engaging opposite Walls of said switch body with a side thereof bearing against said actuator means to urge said actuator means in a centered manner toward the opening said actuator means substantially fills; a contact carrier having a plurality of fixed contacts electrically bridged and carried near a center portion thereof and including outwardly extending members interlocking with portions of said actuator means to control relative movement between said actuator means and said contact carrier along a plane normal to the direction of actuator pivotal movement, said contact carrier including cam shaped portions formed on either side of said contact carrier carried contacts; fixed contacts symmetrically spaced apart and carried in said plate engaged by said cam portions formed on said contact carrier to center said contact carrier relative to said fixed contacts and said actuator means; and a compression spring compressibly carried between said actuator means and said contact carrier to center said actuator means relative to said fixed contacts during a static condition of said switch, said compression spring being compressed when said actuator mean is pivoted driving said contact carrier in the direction of pivotal movement carrying the cam portions along the surface of said fixed contacts for a predetermined distance and snapping said contacts carried by said contact carrier into sliding engagement with said fixed contacts as the actuator means reaches an extreme of pivotal movement.

2. An electric switch comprising: a switch housing means having an opening at one end, a plurality of spaced fixed contacts carried by said housing means and having end portions which project interiorly of the housing means, an actuator means extending through said opening and pivotally supported by said housing means for movement in opposite directions from a center position about an axis extending transversely of the housing means, a contact carrier slidably connected with said actuator means for linear movement relative thereto in a direction generally normal to said pivot axis, a compression spring having one end in abutting engagement with said actuator means and its other end in abutting engagement with said contact carrier for biasing the latter in a direction away from said pivot axis and into engagement with said end portions of said fixed contacts, said contact carrier having a plurality of spaced cam portions engageable with said fixed contacts when said actuator means is in its center position and having a bridge conductor disposed between said cam portions and which is engageable with first and second ones of said fixed contacts when said actuator is pivotally moved in first and second directions from its center position, respectively, and a second spring means cooperably engageable with said housing and said actuator means for biasing the latter toward its center position, said actuator means when moved in said first and second directions from its center position causing first and second ones of said cam portions to ride on said end portions of said first and second ones of said fixed contacts and thereby causing said contact carrier to be moved toward said pivot axis in opposition to the biasing force of said compression spring until said cam portions clear the innermost ends of said end portions whereupon said compression spring causes said contact carrier to be rapidly moved away from said pivot axis and said bridge conductor to engage said first and second ones of fixed contacts with a snap action, respectively.

3. An electric switch for controlling energization of either a first or second electric circuit means, said switch comprising: a switch housing having a base at one end and defining a central opening, first and second spaced pairs of fixed contacts carried by said base and having rounded end portions which project interiorly of said switch housing, a manually manipulatable actuator means extending through said opening and pivotally supported by said housing for movement in opposite directions from a center position about an axis extending transversely of the housing, a contact carrier made from an electrically insulated material and slidably connected with said actuator means for linear movement relative thereto in a direction generally normal to said pivot axis, a compression spring having one end in abutting engagement with said actuator means and its other end in abutting engagement with said contact carrier for biasing said contact carrier away from said pivot axis and toward said base, said contact carrier having first and second spaced pairs of projections extending toward said base and having tapered opposed sides and with one of said tapered sides of each of said first and second pairs of projections being in engagement with said first and second pairs of contacts when said actuator is in its center position, said contact carrier carrying a bridge conductor disposed between said first and second pairs of projections and with the bridge conductor being disengaged from both of said first and second pairs of fixed contacts when said actuator means is in its center position, and a torsion spring carried by said actuator and having its opposite ends in engagement with said housing for biasing said actuator means toward its center position, said actuator means when manually moved in first and second directions from its center position respectively causing said first and second projections to ride on said end portions of said first and second fixed contacts and with the end portions camming said contact carrier toward said pivot axis in opposition to the biasing force of said compression spring until said first and second cam portions clear the innermost ends of said end portions of said first and second fixed contacts whereupon said compression spring causes said contact carrier to be rapidly moved away from said pivot axis and said bridge conductor to engage said first and second fixed contacts with a snap action, said torsion spring returning said actuator means to its center position upon said actuator being released.

References Cited UNITED STATES PATENTS 2,565,863 8/1951 Linn 200'68 2,831,082 4/1958 Mason 200-68 3,222,467 12/ 1965 Meyer. 3,329,785 7/1967 Baer et a1. 200-68 FOREIGN PATENTS 568,686 1/ 1933 Germany.

OTHER REFERENCES Kohl, German application No. 1,012,353, published July 1957, 1 sheet drawing, 2 pp. spec. (copy ZOO-67A).

ROBERT K. SCHAEFER, Primary Examiner.

20 D. SMITH, Assistant Examiner.