US3098905A

US3098905A - Snap-action switch

Info

Publication number: US3098905A
Application number: US146608A
Authority: US
Inventors: Fred N Anderson
Original assignee: Cherry Electrical Products Corp
Current assignee: Cherry Corp
Priority date: 1961-10-20
Filing date: 1961-10-20
Publication date: 1963-07-23
Anticipated expiration: 1980-07-23
Also published as: GB975732A; NL283734A; DE1246083B; NL125735C

Description

July 23, 1963 F. N. ANDERSQN SNAP-ACTION SWITCH Filed 001:. 20, 1961 INVENTOR. i250 M/YIVDEKSO/V 3,@8,% Patented July 23, 1963 33%,965 SNAP-ACTEGN SWITCH Fred N. Anderson, Highland Park, llh, assignor to Cherry Electrical Products Corps, Highland Park, 1th, a corporation of Illinois Filed Get. 20, 1961, Ser. No. 146,6tl8 4 Qlairns. (Ci. zoo-s7 My invention relates to a new and useful improvement in a snap action switch and more particularly to a. switch having a movable blade that by means of an over-centering device is moved with a snap action into and out of circuit making contact.

A particular object of my invention is in the provision in a snap action switch of this character of an actuator that has a positive path to travel, and which engages a tension member at a point immediately adjacent to the pivotal connection of the movable switch blade and its supporting member.

A further object of this invention is in the provision in a snap action switch of this character of a movable switch blade that is formed so as to provide a greater contact area with its terminal pivot post thus assuring a greater current conductive connection therewith.

A still further object Of this invention is in the provision in a snap action switch of this character of a movable blade tensioning member in the form of a coil spring, wherein the coils of such spring are disposed entirely to one side of the terminal pivot post, with the coils of the spring in the path of the switch actuator. The coil spring, as a tensioning member for the movable blade, is provided with an elongated neck terminating into a hook which by the construction of the movable blade has a positive connection therewith.

Another important object of my invention is in the provision in a switch of this character of an arrangement of parts which properly locate the tension member in a pre-determined position with respect to the movable switch blade and the switch blade actuator.

Yet another object of my invention is in the provision in a switch of this character of a cantilever movable switch blade that will move relative to -a stationary contact with a rocking motion which will effect a wiping action between electrical contacts.

Yet another object of my invention is in the provision in a switch of this character of an arrangement of parts that is economical in manufacture, simple in assembling, and positive in its operation.

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 my improved snap action switch.

FIG. 2 is a side elevational view of my switch with the cover removed.

'FIG. 3 is a side elevational view of the interior surface of the cover for the snap action switch.

FIG. 4 is aside elevational view of my switch showing the parts thereof in an actuated position.

FIG. 5 is a perspective view of the internal parts of my improved snap action switch.

FIG. 6 is a detailed sectional view taken on line 2-2 of FIG. 2, and

FIG. 7 is a fragmentary perspective view of a portion of the cover.

This application is a continuation-impart of and constitutes an improvement upon the snap action switch shown, described, and claimed in my co-pending application Serial No. 125,776, dated July 21, 1961.

My improved snap action switch includes a housing generally shown as at 10. This housing is provided with a complementary side cover 11 Within the housing 10 there is a hollowed out cavity generally indicated as at 12. The side cover 11 is provided with a complementary partial cavity indicated as at 13. Correctly positioned within the cavities Hand 13 of the housing to and cover 11 is the switch mechanism of this invention.

The switch mechanism includes a pair of spaced apart fixed contact bearing

terminals

14 and 14. These

terminals

14 and 14 extend through slots formed in the end wall 15 of the housing 10. Each of the terminals 14 and 14' have their corresponding opposite edges notched as at 16 and 17 as viewed in FIG. 5. The notches formed in the one corresponding edge of each of the terminals 14- and 14 fit into the slots formed in the end wall 15 of the housing 10. The notches 17 formed in the corresponding opposite edges of the terminals 14 and 14' receive the end wall 18 of the cover 11. The ends of the

terminals

14 and 14 which are positioned within the

cavities

12 and 13 of the body 10 and cover 11 are generally T-shaped as at 19. The T-shaped ends 19 of the terminals 14 and :14 providing laterally extending lugs 19 which fit into horizontally aligned recesses 2i and 21 formed in the walls of the

cavities

12 and 13, respectively. It is thus readily seen that between the T-shaped ends 19 and the side notches 16 and 17 the terminals 14 and 14' will be correctly positioned within the switch casing.

Each of the terminals 14 and 14' provide spaced apart confronting contacts 22 and 23. A terminal pivot post 24 is provided as part of the switch mechanism and it extends into the cavity 12 of the housing 10 through the bottom wall 25 thereof. The terminal pivot post 24, like the

terminals

14 and 14 has its opposite edges notched as at 26 and 27, with the notch 26 positioned in a slot 28 formed in the bottom wall 25' of the housing 10, and the notch 27 formed to receive the bottom wall 29 of the cover 11.

The inner confronting walls of the

cavities

12 and 13 are each provided with aligned recesses 311 and 31 which are adapted to receive oppositely extending lugs 32 carried by the terminal pivot post 24, only one of such lugs 32 being shown. The end of the terminal pivot post 24 which is positioned within the casing of the switch is bifurcated to provide spaced apart

pivot post arms

33 and 34. One face as well as opposite corresponding edges of each of the

posts

33 and 34 are provided with V-notches 35 as seen in FIG. 5.

Formed from a spring material is a substantially flat switch blade 36. The body of the switch Iblade 36 is divided into equal portions by a partially extending narrow slot 37. The free ends of these equal portions of the isody of the switch blade 36 are provided with corresponding shoulders 38. The arrangement is such that the shoulders 38 as well as the ends 39 of the equal portions of the body of the movable switch blade 36 on either side of the slot 37 are positioned into pivotal contact with the V-notches 35 formed in the faces and opposite sides of the

pivot posts

33 and 34.

The switch blade 36 has formed therein a diagonal slot 40 which extends from one longitudinal edge of the blade 36 in the direction of and terminates short of the slot 37. However, the slot 40 terminates at a point adjacent to and in the plane of the slot 37. By the slot 40 a cantilever type blade is formed which has a resilient end 41 which carries thereon a contact 42. The switch blade 36 is held in contact with the pivot posts 33' and 34- under tension by a tension member in the form of a coil spring 43. One end of the coil spring provides an elongated neck 44 which terminates into a book 45 which extends through and is in contact with the base of the diagonal slot 40. The opposite end of the coil spring 43 provides a reversely formed hook member 46 which is adapted to be hooked upon a spring pin 47. It should be noted that when the heretofore described parts are assembled within the casing of the switch the convolutions of the coil spring lie entirely to one side of the

pivot posts

33 and 34 directly in line of a switch actuator 48. The long neck A- of the tension member 43 extends between the

pivot posts

33 and 34 and lies freely within the confines of the slot 37 formed in the blade 36.

The opposite end wall 49 of the body It} is provided with a notched out portion which is of a depth less than the cavity 12 formed in the body It). The base of the notched-out portion 50 is provided with a circular pit 51 in which is seated one end of the spring pin 47. The cover 11 adjacent one end 52 thereof is provided with a corresponding aligned recess 53 into which freely projects the opposite end of the spring pin 47 when the cover 11 is mounted on the body It) as shown in FIG. 1.

The end 52 of the cover 11 provides a lateral extension 54 which provides a rear wall for the notched-out portion 50 of the end wall 49 of the body It) when the cover is mounted thereon. The cover 11 adjacent the recess 53 inwardly of the lateral extension 54 is provided with spaced apart bosses 55. These bosses 55 project inwardly of the notched-out portion 5t) and lie above and below the spring pin 47 and maintain the hook 46 of the tension member 43 on the spring pin 47.

The cover 11 on its inner face adjacent the bosses 55 provides an elongated extending lug 56. This lug 56 is adapted to lie against one side of the coils of the tension member 43 so as to maintain the same in a predetermined position within the casing of the switch. The lug 56 is elongated so that it will always have a surface in abutment with the coils of the spring even as the same is moved by the actuator 48 into the position shown in FIG. 4.

The body in the top wall thereof is provided with a passage 5*? which communicates with the cavity 12. Within the passage 57 is slidably projected the stem portion 58 of the switch actuator 48. The actuator 43 is formed in a substantially L-shape with the lower corner thereof notched out as at 59, and with a portion 60 of the base leg thereof extending in a depending plane with respect thereto.

A laterally extending guide 61 is carried by the depending portion 60 as seen in FIG. 5. This guide 61 is adapted to ride in a groove 62. formed in the side wall of the body *10. The L-shaped actuator 58 provides a shoulder 63 which in normal position is in contact with a portion of the top wall '64 of the body '10 which defines the cavity =12. This shoulder 63 prevents outward movement of the actuator 4-8 from within the cavity 12 of the body 10.

By reason of the actuator 48 being L-shaped, an offset foot portion 65 thereof, will engage the tension spring 43 at a point adjacent the bifurcated ends of the pivot posts 33 and 34 as seen in FIGS. 2 and 4, and thus be laterally distant from the long axis of movement of such actuator, for a purpose hereinafter explained.

When the actuator 48 moves inwardly of the body 10 in its controlled path, it will depress the tension member 43 below the point of pivotal connection between the blade 36 and the pivot posts 33 and 34, creating increased tension in the blade 36 causing the same to move with a snap action into the position shown in FIG. 4 where the contact 42 of the blade 36 engages contact 23 of the fixed terminal member 14. As the blade 35 is of a cantilever configuration the contact 42. will actually rock on the contact 22. before the blade 36 moves with a snap action into its actuated position.

A positive action of the blade 36 results from the fact that the tension member 43 is actuated through the pressure of the foot 65 of the switch actuator 48 engaging a portion of the tension member 43 at a point as close as possible to the pivotal connection of the blade 36 with the pivot posts 33 and 34, thus reducing the amount of deformation of the spring necessary to actuate the blade. This also has a direct bearing on the amount of external pressure required to cause movement of the actuator relative to the spring.

In FIG. 3 it will be noted that adjacent the corner of the cover 11 defined by the

walls

18 and 29 thereof there is formed on the exposed surface a laterally extending rib: -66. This rib 65 is adapted to sit in a mar- 'ginal channel 67 formed in the confronting exposed surface of the body 1h. The marginal rib 6:5 is interrupted by a passage 68 which receives the notched out portion 17 of the fixed terminal 14 when the cover is mounted in a closing position upon the body 10.

From the foregoing construction it is apparent that I provided a movable switch blade 36 which has a greater area of current conductive contact with the pivot post

arms

33 and 34 of the fixed terminal 24. This by reason of the requirement of only a very narrow slot 37 formed in the blade 36 in which is positioned the thin elongated neck 4 of the tension member 4-3. This neck 44 also permits the pivot post

arms

33 and 34 to be of a size presenting a greater pivotal contact area with the movable blade 36. The diagonal slot 44 assures proper positioning of the hook 45 of the tension member 43 to the blade 36 as well as forming a cantilever end 41 for the movable blade.

By incorporating confronting and cooperating connecting parts on the body 10 and cover II, -I have provided a switch casing in which the switch mechanism may be readily and simply assembled. By reversing the hook members 45 and 46 of the tensioning member 43, I have provided a pivoting connection between the blade 36 and the tensioning member 43 which increases the life of the tensioning member 43 and prevents the same from transmitting a bending motion on to either end of the tension member as.

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

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

1. A snap-action switch housing, having a body normally open at one side and a cover therefor, with said body and cover providing an interior cavity containing a snap-acting mechanism including (a) an elongated coil spring,

(b) said coil spring having one end connected to a movable switch blade and its opposite end attached to a supporting means carried by said housing,

(6) a supporting means extending transversely between said body and said cover and upon which one end of said coil spring is hooked,

(d) said housing providing a compartment for said supporting means,

(e) said compartment comprising a notched-out opening formed in one end wall of said body of a depth less than said cavity formed therein,

(f) and means carried by a corresponding end wall of said cover for closing said notched-out opening and for positioning the hooked end of said coil spring upon said supporting means for maintaining said coil spring in a predetermined longitudinal plane with respect to the movable switch blade.

2. A snap-action switch housing as defined by claim 1 wherein said means for closing said notched-out opening comprises laterally extending projections integrally formed on said cover for insertion into said notched-out opening on three sides of said supporting means for maintaining said coil spring thereon.

3. A snap-action switch housing as defined by claim 1 wherein said supporting means comprises a pin projecting laterally with respect to said body and said cover and upon which is hooked one end of said coil spring, one end of said pin centered in said compartment provided by said body and having its opposite end positioned centrally with respect to said closing means provided by said cover.

4. A snap-action switch housing, having a body normally open at one side and a cover therefor, with said body and cover providing an interior cavity containing a snap-acting mechanism including (a) an elongated coil spring,

(b) said coil spring having one end connected to a movable switch blade and its opposite end attached to a pin carried by said housing,

(0) a pin extending transversely between said body and said cover and upon which one end of said coil spring is hooked,

(d) said housing providing a compartment for said pin,

(f) and means carried by a corresponding end wall of said cover for closing said notched-out opening and for positioning the hooked end of said coil spring upon said pin for maintaining said coil spring in a predetermined longitudinal plane with respect to the movable switch blade,

(g) said closing means comprising laterally extending projections integrally formed on said cover for insertion into said notched-out opening on three sides of said pin for maintaining said coil spring thereon.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

1. A SNAP-ACTION SWITCH HOUSING, HAVING A BODY NORMALLY OPEN AT ONE SIDE AND A COVER THEREOF, WITH SAID BODY AND COVER PROVIDING AN INTERIOR CAVITY CONTAINING A SNAP-ACTING MECHANISM INCLUDING (A) AN ELONGATED COIL SPRING, (B) SAID COIL SPRING HAVING ONE END CONNECTED TO A MOVABLE SWITCH BLADE AND ITS OPPOSITE END ATTACHED TO A SUPPORTING MEANS CARRIED BY SAID HOUSING, (C) A SUPPORTING MEANS EXTENDING TRANSVERSELY BETWEEN SAID BODY AND SAID COVER AND UPON WHICH ONE END OF SAID COIL SPRING IS HOOKED, (D) SAID HOUSING PROVIDING A COMPARTMENT FOR SAID SUPPORTING MEANS, (E) SAID COMPARTMENT COMPRISING A NOTCHED-OUT OPENING FORMED IN ONE END WALL OF SAID BODY OF A DEPTH LESS THAN SAID CAVITY FORMED THEREIN, (F) AND MEANS CARRIED BY A CORRESPONDING END WALL OF SAID COVER FOR CLOSING SAID NOTCHED-OUT OPENING AND FOR POSITIONING THE HOOKED END OF SAID COIL SPRING UPON SAID SUPPORTING MEANS FOR MAINTAINING SAID COIL SPRING IN A PREDETERMINED LONGITUDINAL PLANE WITH RESPECT TO THE MOVABLE SWITCH BLADE.