US3275768A - Snap-action electric switch - Google Patents

Description

Sept. 27, 1966 K. J. BATCHELLER SNAP-ACTION ELECTRIC SWITCH Filed April 15, 1964 A V a.

INVENTOR KENT J. BATCHELLER ATTORNEYS III A United States Patent Office Patented Sept. 27, 1966 3,275,768 SNAP-ACTION ELECTRIC SWITCH Kent J. Batcheller, 30 Brush Hill Road, Newton, Mass. Filed Apr. 13, 1964, Ser. No. 359,123 1 Claim. '(Cl. 200-76) This invention relates to an electric switch designed to carry relatively heavy currents and to have a fast make and break. It is also an object of the invention to provide a switch structure consisting of simple parts which can quickly and easily be assembled. The switch hereinafter described is of the push-pull type having a plunger which is pushed to open the switch and is pulled to close the switch, there being a spring toggle connection between the plunger and a contact blade which acts to snap the blade quickly to or from contact -with a pair of fixed terminals.

For a more complete understanding of the invention, reference may be had to the following description thereof, and to the drawings, of which FIGURE 1 is a perspective view of an embodiment of the invention, the structure being shown with a body or casing of transparent material so that the inner parts are visible;

FIGURE 2 is an elevational view of the same, the parts being in open-switch position;

FIGURE 3 is an exploded perspective view of the same, showing the individual parts; and

FIGURE 4 is a section, on an enlarged scale, taken on the line 44 of FIGURE 2.

The switch illustrated in FIGURES 1-4 comprises a housing or body consisting of two identically formed members which are of insulating material, preferably a molded therrno-setting synthetic resin such as Bakelite. As shown in FIGURE 3, each member 10 is generally rectangular in shape and is provided with a recess 12, the two recesses constituting a hollow or cavity when two of the members are put together face to face. The bottoms of these cavities are parallel inner Walls of the hollow which confine and guide a U-shaped yoke 14, this yoke being adapted to move up and down for the operation of the switch as hereinafter described. The U-shaped yoke has a horizontal base 16 and two vertical arms 18. For convenience of description, the switch structure is described in the following specification and in the claims as being in the upright position shown in FIGURES 1 and 2, but it is evident that it can be used in any position. Extending horizontally across the inner wall of each arm 18 is a groove 20 adapted to receive an end of a leaf spring 22 as hereinafter described. The base 16 of the yoke is longitudinally slotted from the a bottom up as at 24 to receive a planar contact blade 26 which is rockably retained in the slot 24 by a pin 28 which passes through :a hole 30 in the base 16 and 'a hole 32 in the blade 26.

The top of each body member 10 is notched as at 34, these notches forming a rectangular passage when the two body members 10 are secured together. In this passage is slidably fitted a flat portion 36 of a push rod 38, the fiat portion preventing the push rod from turning on its own axis. Two terminal members 40 extend through and are fixed in the bottom of the body, each member 10 having shallow recesses 41 in which the terminal members 40 fit. As shown, the upper end portion of each terminal member 40 is bifurcated to form two contact elements 42 which are inclined in opposite directions to make acute angles with a vertical plane. The contact blade 26 has downwardly projecting elements 44 at each end thereof which are similarly inclined from the vertical to engage the inclined end portions 42 of the terminal members 40. The lower ends of the terminal members 40 which are outside of the body may be provided with the customary screws 46 by which wires can be attached to the terminal members.

The push rod 38 is provided with lateral notches or grooves 48 on opposite sides thereof at its lower end. An end of each of the two leaf springs 22 engages in one of these grooves 48. The leaf springs 22 are made of short strips of spring steel which are suitably tempered. Each spring when unstressed is in the form of a V, the legs of which make an angle of or degrees with each other. The extremities of these legs are bent outwardly to form lips 50 for engagement in the grooves 20 in the yoke 14, and the grooves 48 at the lower end of the push rod 38, this being indicated in FIGURE 2. The dimensions of the yoke 14 and springs 22 are such that the springs must be distorted or sprung to a shape somewhat as illustrated in FIGURE 2, the legs of the V then making an angle of about 45 degrees with each other. FIGURE 2 shows the position of the parts when the switch is open, that is, when the yoke and the contact blade carried thereby is in its elevated position.

At this time the push rod is in its lowermost position. To close the switch, the push rod is pulled up as indicated in FIGURE 1. When it has been pulled part way up, the springs 22 snap it strongly the rest of the way up, and at the same time snap the yoke down to its lowermost position, as indicated in FIGURE 1, in which position the tongues 44 of the contact blade are in engagement with the tongues 42 of the terminal members 40. Since the contact blade is rockable about the pin 28, it automatically equalizes the pressure between its several tongues 44 and the opposing tongues 42. In like manner when the push rod is moved downward, the springs 22 snap the push rod through the latter part of its downward movement and at the same time snap the yoke and contact blade upward so that the latter is quickly separated from the terminal members 40.

To hold the body members together in assembled relation, any suitable fasteners such as hollow rivets 52 may be employed. A cover member 54 may also be employed to extend over the top of the body and down on the faces of the body members 10 a sufficient distance to accommodate the upper rivets 52. A throat 56 is secured to the cover member 54 to accommodate the push rod 38 which has a sliding fit therethrough. A finger piece or handle 58 is screw threaded or otherwise fastened to the upper end of the push rod 38 to facilitate the manipulation thereof.

A valuable feature of the construction hereinbefore described is that it is capable of quick and easy assembling. The inner walls of the hollow or cavity 12 confine and guide the movements of the yoke 14 and also keep the springs 22 in place. The push rod, springs, yoke, contact blade and terminal members can quickly and easily be assembled on one of the body members 10. The other body member is simply placed on top and a cover member 54 is moved down over the end of the push rod 38 to embrace the upper parts of the body members 10. This holds the assembled switch in assembled condition until the rivets 52 are inserted and secured:

The finger piece 58 is then mounted on the outer end of the push rod 38, completing the assembling of the switch.

I claim A snap-action electric switch comprising a hollow body consisting of two members of insulating material fastened together, a push rod extending slidably through the topof said body, two terminal members extending throughand fixed in the bottom of said body, a planar contact blade in said body movable in its own plane downinto contact with said terminal members and up out of contact with said terminal members, and means responsive to a downward movement of said push rod to raise said contact blade out of contact with said terminal members and responsive to an upward movement of said push rod to move said contact blade down into contact with said terminal members, said means comprising a spring toggle mechanism operatively connecting said push rod and said contact blade, said contact blade being. mounted for limited rocking movement in its own plane for balanced 1 engagement with the two said terminal members.

References Citedrby theExaminer UNITED STATES PATENTS 1,790,974 2/1931 Cox 200-76 1,893,027 1/1933 Helsel 200-164 X 2,384,412 9/1945 Woods 200-76 10 3,017,471. 1/1962 Karch 200 -76 FOREIGN PATENTS 560,352" 9/1957 Belgium,

15 ROBERT K. SCI-IAEFER, Primary Examiner.

KATHLEEN H. CLAFFY, ROBERT S.: MACON;

Examiners.

W. C. GARVERT, Assistant Examiner,

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