US3073923A - Electric snap-action switch - Google Patents

Description

Jan. 15, 1963 F. N. ANDERSON EIAL ELECTRIC SNAP-ACTION SWITCH Filed Aug. 20, 1959 INVENTORC [1. 69/2 3 da 4 AME you States Our invention relates to a new and useful improvement in an electric snap-action switch and more particularly to a type of snap-action switch in which a quick and positive snap-action of the switch blade is attained.

The principal object of our invention is in the provision in a switch of this character which permits a rockingwiping break action of contacts.

Another object of our invention is in the provision in a switch of this character of a cantilever contact bearing switch blade which permits a rocking-wiping break between contacts.

A further object of our invention is in the provision in a switch of this character of a breaking action whereby the switch contacts are self-cleaning.

Still a further object of our invention is in the provision in a device of this character of an arrangement of parts whereby they may be housed within a compact compartment without the necessity of rivets or screws.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

FIG. 1 is a perspective view of our improved snapaction switch;

FIG. 2 is a side elevation, sectional detailed view taken on line 22 of FIG. 1;

FIG. 3 is a side elevation, sectional detailed view similar to FIG. 2 but showing the parts in actuated position; and

FIG. 4 is an exploded view of the parts of our invention.

Our invention relates to an improved snap-action switch comprising a housing 10. The housing includes complementary sections 11 and 12 adapted to be mounted together in facial abutment as seen in FIG. 1. Each side wall 13 and 14 of the respective sections 11 and 12 is provided with complementary cavities. One of such cavities is shown at 15 formed in the wall 14 of the section 12, FIGS. 2 and 3. It should be noted that the cavity formed in the wall 13 of the section 11 is identical to the cavity 15 as shown.

The end walls 17 and 16 of each of the sections 11 and 12 have formed therein horizontally aligned slots 18 and 19. Inserted into the slot '18 is a terminal plate 20. This plate 20 adjacent its inner end is provided with laterally extending lugs 21 and 22. These lugs 21 and 22 are adapted to be positioned in horizontally aligned grooves formed in the inner opposite faces of the side walls 13 and 14. One of such grooves 23 is shown in the side wall 14 in FIG. 4. Into this groove 23 will be positioned the lug 21 of plate 20, while the lug 22 will be positioned in a like groove formed in wall 13 (not shown).

A second terminal plate 24 is adapted to be positioned in slot 19. This plate 24 like plate 20 is provided with laterally extending lugs 25 and 26. When the plate 24 is properly mounted in slot 19 the lug 25 will sit in a groove 27 formed in the inner face of wall 14. Lug 26 of plate 24 will likewise sit in a corresponding groove (not shown) formed in the opposite inner face of the wall 13.

A base terminal plate 28 is positioned in confronting ice slots formed in the opposite sectioned end wall of the housing 10. One of such slots is shown as at 29. The base terminal plate 28 is provided with laterally extended positioning lugs 30 and 31. The lugs 30 and 31 are insertable into grooves formed in opposite inner faces of the side walls 14 and 15. One of such grooves 32 is shown in FIG. 4.

The base terminal plate 28 provides a pair of spaced apart vertically extending fingers 33 and 34. When the base terminal plate 28 is positioned in the housing 10 by reason of the lugs 30 and 31 the fingers 33 and 34 will be in a preselected relationship with respect to the terminal plates 20 and 24. One side of each of the fingers 33 and 34 are V-notched as at 35.

Into the V-notches 35 is adapted to be seated the tapered bifurcated ends 36 and 37 of a switch blade 38. This switch blade 38 has a slot 39 formed therein extending transversely to the longitudinal length of the blade. Under such construction the blade is of a cantilever type having a contact carrying member 40 at one end thereof. The width, thickness and material of the switch blade 38 are such that the cantilever portion thereof flexes within its elastic limit when under the force loads produced by the associated parts within the switch.

A coil spring 41 is connected as at 42 to the blade 38. This spring 41 projects between the fingers 33 and 34 and is connected at its opposite end to a lug 42 struck from the base terminal plate 28.

As viewed in FIG. 2 the lug 42 lies in a higher horizontal plane than does the junction of the ends 36 and 37 of the blade 38 with the fingers 33 and 34. Under such an arrangement the spring 41 will normally cause the switch blade 38 to assume the position shown in FIG. 2, where one of the contacts of the member 40 will be in engagement with the contact of the terminal plate.

-A switch actuator is shown at 43. The actuator 43 comprises an exposed circular body portion 44 which normally projects upwardly from the housing 10 through a suitable opening 45. The actuator 43 has an elongated rectangular shaped lower body portion 46 which is of a longitudinal length slightly greater than the distance between the inner confronting faces of sides 13 and 14 and the housing 10. To position the lower body portion 46 in the housing 10 the ends of such lower body portion 46 are adapted to be slidably contained in opposite vertical recesses formed in the inner faces of the side walls 13 and 14. One of such recesses 47 is shown in FIGS. 2, 3 and 4.

Referring to FIG. 1 there is shown a pivotal lever 48. This lever is adapted to be yieldably depressed so as to slidably move the switch actuator 43 to operate the snapaction switch as will be hereinafter explained. This lever 48 is formed from a resilient material and is substantially Z-shaped as shown. One depending leg 49 of the lever 48 is provided with a portion 56 struck outwardly therefrom. The leg 49 is adapted to sit in a slot 51 formed in the top walls of each of the sections 12 and 13. When the leg 48 is so positioned in the slot 51 the portion 50 will frictionally engage a shoulder 52 extending transversely to the longitudinal length of the slot 51. Thus it is shown that we have provided a simple yet effective means for pivotly connecting the lever 48 to the housing 10.

The opposite end of the lever 43 provides two laterally extending ears 53 and 54 between which a suitable roller 55 or the like is mounted.

The underside of the medial portion of the lever 48 engages the exposed circular body portion 44 of the switch actuator 43 so that when the lever is yieldably depressed it will slidably move the switch actuator 43 3 through the housing for a purpose hereinafter made apparent.

The actuator 43 will rest on the spring 41 when it is in its normal inactive position. When the actuator 43 is depressed, it will bear against and distort the spring 41. By such distortion the tension centerline of the spring 41 is moved downwardly below the axis of the switch .blade 38. In such new distorted position the tension of the spring 41 has been increased and has a directional pull upon the switch blade 38, which is opposite to its normal directional pull and results in a downward snap movement of the switch blade 38 about its pivotal connection to the fingers 33 and 34. When the depressive force of the actuator 43 is released the spring 41 will move up wardly under the influence of the flexural forces inherent therein until it passes its coplanar position with respect to the longitudinal plane of the switch blade 38. Thus, the switch blade 38 will again be pivoted about its connection with fingers 33 and 34 to its normal position shown in FIG. 2, where the spring 41 is under its minimum tension.

It should be noted, however, that by the specific construction of the switch blade 38 there is a flexing cantilever action in both the longitudinal and transversal axes of the thin contact bearing member 40. The resultant of said two actions produces a wiping and torsional breaking action between mating contacts. Such action aids the breaking of welds and promotes a fast and positive break between such mating contacts. This cantilever movement will also result in a self-cleaning action between the contacts as they are forced to make and break. It should be noted that the rectangular shaped body portion 46 of the actuator 43 prevents such actuator 43 from being displaced with respect to the housing 10.

While we have illustrated and described the preferred form of construction for carrying our invention into effect, this is capable of variation and modification without departing from the spirit of the invention. We, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail ourselves of such variations and modifications as come within the scope of the appended claim.

Having thus described our invention, what we claim as new and desire to protect by Letters Patent is:

A snap action switch comprising a) a housing providing an interior cavity,

(b) a pair of contact bearing terminal plates extending through slots formed in one end wall of said housing and into said cavity,

(0) a terminal plate extending in a slot formed in the opposite end Wall of the housing into said cavity,

(d) said terminal plate at its interior end portion providing spaced apart parallelly extending arms extending at right angles with respect to said terminal plate and in spaced parallel relation with respect to the opposite side walls of said housing,

(e) a pivotable cantilever switch blade positioned within said cavity and having one end in contact with said spaced apart arms of said terminal plate and its opposite free end in engagement with one of the contacts of said contact terminal plates,

(f) a lug formed on said terminal plate in spaced relation with respect to said arms,

(g) a spring member extending between said arms and having one end connected to said lug and its opposite end connected to said switch blade,

(11) an actuator substantially rectangular in cross section within said housing extending between and in contact with the side walls thereof and transversely of said spring member,

(i) actuator guide slots formed in the vertical side walls of said housing for slidably receiving the opposite edge portions of said rectangular shaped actuator for guiding the reciprocal vertical movement thereof,

(1') an opening formed in the top wall of said housing in vertical alignment with said guide slots formed in the side walls of said housing and through which a reduced circular head of said actuator extends,

(1:) said actuator extending across and in contact with said spring member adjacent the point where said spring extends between said arms of said terminal plate so that when said actuator is moved in a guided path through said guide slots toward said spring member the same will compress said switch blade to effect a snap action movement of the cantilevered end thereof into and from engagement with the contacts provided by said contact bearing terminal plates,

(1) and a pair of locating slots formed in the side walls of said housing beneath and in vertical alignment with said actuator guide slots adapted to receive positioning elements laterally extending from opposite side edges of said terminal plate adjacent the base of the vertically extending parallel spaced arms for positioning said terminal member so that said arms thereof extend in a juxtaposed vertical plane with respect to the guided path of movement of said actuator.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Australia Aug. 10, 1959 Germany May 9, 1957 France May 25, 1959

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