US2776347A - Snap switch - Google Patents

Description

Jan. 1, 1957 A. A. ALLEN 2,776,347

SNAP SWITCH Filed June 16, 1955 j g4 INVENTOR.

ALAN/4. AME/v @j www United States Patent O SNAP SWITCH Alan A. Allen, Beverly Hills, Calif.

Application June 16, 1955, Serial No. 515,876 s claims. (ci. zoo- 67) This invention relates to a snap switch construction which uses a switch blade of resilient material and which isvpre-stressed in a manner to set up a deformation, creating one area of high sensitivity that, when subject to relatively small movement, will impart to another area of` the blade a rapid and relatively larger movement or displacement. ln a miniature snap switch of the above character, the blade may be in the nature of one-half inchlong and be made of flat spring stock some .002" to .004l thick. Although such blades may be initially placed under stress so as to have snap action, their action is not always uniform and, therefore, not wholly dependable. Blade chatter is frequent during action of the switch, as well as blade vibration. Also, the blade movement may be subject to high momentum forces which may materially aiect the action thereof. w

Accordingly, it is an object of the invention to provide, in a switch of the character referred to and having a stressedj switch blade, means to eliminate chatter and vibration of the blade and, thereby, provide for greater uniformity of the blade movement and improved control of said movement.

Another object of this invention is to provide a switch blade that is adapted to be transversely flexed to induce longitudinal lieXure and to so conne, restrict and/or control the action of said blade in the vicinity of such transverse ilexure as to largely eliminate blade chatter and vibration.

A further object of the invention is to impart a strong return force to the switch blade whereby positive return, after actuation, is assured under all conditions of operation, under both static and high momentum conditions.

As the following detailed description of the invention proceeds, the foregoing objects and other objects, features and advantages of the invention will become more clearly evident. Said description is based on the accompanying drawing of a preferred form of the invention and in which like numerals designate similar parts throughout the several views.

In the drawing:

Fig. 1 is a partial side elevational and partial longitudinal sectional view of a snap switch embodying the features of the present invention.

Fig. 2 is a plan view thereof with a portion removed to expose the interior construction.

Fig. 3 is a perspective view of a novel element that cooperates with the blade of said switch to control the action of the latter.

Fig. 4 is an enlarged fragmentary sectional view as taken on line 4 4 of Fig. l, the switch blade being shown in unactuated condition.

Fig. 5 is a similar view showing the actuated condition of the blade.

Referring to the drawing in greater detail, the switch comprises a two-part dielectric housing 5 formed as a base or body 6 and a cap or cover '7. Said base is provided with a platform 8, at one end, and with a support portion 9, at the opposite end.

Patented Jan. l, 1957 Platform 3 supports a switch blade 10 while the portion 9 carries a contact plate 11. Beneath plate 11, the housing base or body 6 mounts a second contact plate 12. A contact 13 on the free end of switch blade 10 normally is in electrical contact with plate 11, as shown, and may be moved into electrical contact with plate 12 when the blade is downwardly flexed.

The switch blade 10 is secured to platform 8 by the end 14 of a terminal 1S. Terminals 16 and 17, respectively, secure the contact plates 11 and 12 in place.

The housing cover or cap 7 is formed to have a socket 18 in which operates an actuator 19 for the spring base 10. Said actuator is provided with transversely spaced projections 20 that are spaced farther apart than the width of platform S (see Fig. 2) and are adapted to press against opposed lateral portions of the spring blade so as to ilex the same across the platformv 8.

Since the contact 13 holds the spring arms 21 of the blade 10 flexed toward each other, as shown in Fig. 2, said blade is stressed and hasvan upwardly eXcd normal position to bring the contact 13 into engagement with the under face of contact plate 11 as in Fig. l. When the actuator 19 is pressed, the resulting transverse ilexure of the blade across the platform 8 (Fig. 5) causes reverse longitudinal flexure of the blade to move the contact 13 into engagement with the upper face of contact plate 12. Also, since, heretofore, the blade was aflixed to its support at the eXtreme end remote from contact 13, the switch blade was prone to vibrate under certain conditions, as for instance shock. When shock is great enough, the blade may flutter and cause loss of electrical contact or even shift from one Contact to the other. Also, when actuated, the blade was subject to chatter to deleteriously affect the operation. `Further, dependence on uniform action could no-t be had under different conditions of use, ashereinbefore mentioned.

To obviate the above faults, the present switch structure provides a control eiement 22 that retains or restrains the spring blade so that the same may function uniformly. As shown, said element 22 is held in place by the reduced end 23 of terminal 15 and a head 2.4 on said end tightly afxes the same in position to overstand the portion of the switch blade that rests upon platform As can be seen from Figs. 4 and 5, the top of platform 8 is found to be transversely convex so as to provide said platform with longitudinal transversely spaced lands 3a lthat serve as supports for the blade part 21a between the head 24 and the bifurcation formed by the spring arms 21. Due to the mentioned upward flexure of blade arms 21, the blade part has a slight transverse flexure that is concave, as seen from above. lt is when this transverse flexure is reversed that the switch blade snaps into contact with plate 12.

Control element 22 has an elongated end 25 that eX- tends from a transverse bend 26 at an obtuse angle 27 with respect to lthe part 2S that is caught under the head 24. Said end 25 may be tapered to provide a point 29. It will be clear, therefore, since part 2S seeks a at position against the blade, the point 29 of angularly bent part 25 impinges on the blade part 21a between the lands 8a, as can be seen in Fig. 4. This tends to increase the transverse flexure of the blade and, thereby, materially reduce blade Hutter or chatter. The part of the blade engaged with table 30 remains substantially flat while the part 21at engaged with lands 8a assumes the exure indicated.

Also, since the impingernent of point 29 rmly holds the blade part against the platform lands Se, the free length of the blade is reduced. The same effects a further reduction or elimination of vibration and chatter.

When actuator 19 is depressed, as shown in Fig. 5, to reverse the transverse exure of blade part 21a and snap the button 13 to engage plate 12, the point 29 of element 22, being substantially immovable, prevents flexure of the middle portion of the blade part 21a. Thus, only the lateral edge portions 31 of part 21 can iiex.

Because of this resistance to transverse fleXure of the blade part between lands Se, a positive force is induced that is effective on said edge portions 31 to return them quickly to the condition of Fig. 4 upon release of actuator 19.

Since variations may be made in the present means that would fall within the scope of the invention, I Wish to reserve to myself all such variations and modifications that fall within the spirit and scope of the appended claims.

I claim:

l. In a snap switch provided with a switch blade having one end affixed to and supported on a platform and having a longitudinally flexible free end, said switch having an actuator to transversely flex a portion of the blade supported by said platform, the improvement that comprises a member in rm impingement with the blade between the points of transverse flexure, said member having a portion affixed with the blade to the platform and a bent portion having a corner edge in the mentioned impingement with the blade.

2. In a snap switch provided with a switch blade having one end aliixed to and supported on a platform and having a longitudinally flexible free end, said switch having an actuator to transversely flex a portion of the blade supported by said platform, the improvement that comprises a member in firm impingement with the blade between the points of transverse flexure, said platform being provided with longitudinal and transversely spaced lands, and the mentioned member impinging the blade on the portion between the lands.

3. In a snap switch provided with a switch blade having one end affixed to and supported on a platform and having a longitudinally flexible free end, said switch hav- Ving an actuator to transversely flex a portion of the blade supported by said platform, the improvement that comprises a member in firm impingement with the blade between the points of transverse flexure, said platform being provided with longitudinal and transversely spaced lands, and the mentioned member being provided with a pointed end bent to impinge on the portion 0f the blade between the lands.

4. In combination, a platform, a pre-stressed switch blade having one end supported by said platform and having an opposite free end, actuator means to transversely flex the blade across the platform and, thereby, longitudinally Hex the free end thereof, and a iiexurecontrolling element fastened to the platform-supported portion of the blade and in impingement with the blade at the point of transverse iiexure.

5. The combination according to claim 2: the exurecontrolling element being bent to form an obtuse included angle between its ends, and means to stress said element to flatten said angle and provide corner-edge impingement of said element with said blade.

6. In combination, a platform provided with a pair of longitudinal and transversely spaced lands, a prestressed switch blade having one end engaged with the lands of said platform and having an opposite free end, actuator means to engage said land-engaged portion of the blade outwardly of the lands to transversely fiex said one end of the blade and, thereby, longitudinally tiex the free end thereof, and a flexure-controlling element fastened to the platform-supported portion of the blade and provided with an end in firm impingement with the latter blade portion between the lands.

References Cited in the file of this patent UNITED STATES PATENTS 2,024,362 Hoopes Dec. 17, 1935 2,275,642 Nordberg Mar. 10, 1942 2,649,520 Hartz Aug. 18, 1953

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