US2447969A - Electric switch - Google Patents

Description

g- 1948. F. VON VOIGTLANDER 2,447,969

ELECTRIC SWITCH Filed Jan. 8, 1947 Patented Aug. 24, 1948 UNITED STATES PATENT O FF ICE.

I ELECTRIC SWITCH Frederick VonVoigtlander, Ann Arbor, Mich.. assignor, by mesne assignments, to Sperti Faraday Inez, a corporation of Ohio: 7 Appiication January 8, 194.7, Serial No. 720,801

This invention relates to features of simplicityand' economy in electric switch constructions, more particularly of the pushbutton type.

This invention has utility when incorporated in a unit adapted to be thrust into a cylindrical socket in thereby installing in a desired position for use. The unit main insulation bodyhas "a central'key socket for'the push element, at normally outward switch open position. a A drive screw assembles the push button element in the body with ahelical compression spring about the screw. A push on the button element or plunger closes the switch circuit at springarms from a pair'of spaced terminals. A yieldablefinger-carrying shell about the body holds the body in a mounting socket therefor. an insulation mounting and theshell areiassembled'by two-self-tapping screws thru the respective terminals. The inter-relation of these parts contributes to a sturdy, compact efiicient switch.

Referring to the drawings:

Fig. 1 is a plan view, with parts broken away, of an embodiment of the invention in a normally-open -type of push button switch, the broken away portion showing the keymeans for holding the button from turning or rotating relatively to the body;

Figrz isa sideview, with themajor portion in vertical section, showing the assembled parts and theswitch features in the normal or open switch position therefor;

Fig. 3 is a View in bottom plan of the push buttonswitch unit of Fig. 1, with one of the terminals removed, thereby to expose fully one of the spring arms of the switch;

Fig. 4 is another bottom plan View of the unit, with the spring arms, as well as the terminals, removed, and a portion of the insulation disk also omitted to expose the spring fingers of the friction lock or socket providing the holding means for locating the insulation body of the unit in installed position for use; and

Fig. 5 is a fragmentary bottom plan view of the main body or insulation housing of the device or unit.

A main member or plastic body I has a major cylindrical exterior portion 2, upward to a slight overhang 3, as a rim or flange. The rim 3 bounds a recess or concentric chamber 4 having a pair of diametrically disposed key lugs 5. The chamber 4 has a bottom 6 with a concentric, slightly greater depth portion I, to provide a seat for helical compression spring 8. The spring 8 is about a drive screw 9 which is freely slid- The terminals, arms,

. '4 claims. (01. 200-159) able thru an opening It] from the bottom of the chamber 4.

With a head H of the screw 9 seated against a central inward offset from a bottom face IZ of the body I-, it is-normally so retained by the action of the'spring 8, for the screw 9, as thru the spring 8, is drive anchoredln a central boss l3 depending from a push button I4, also preferably of plastic material. Before thrusting the screw it into an axial recess in the boss I3, an eyelet or sleeve I4 is press fitted thereabout as a reinforcement for the plastic element I4, Outside the region of the spring 8 inits contact with the underside of the'pushbutton I4, the button I4 has arc-shaped recesses or outwardly open grooves I5" adapted to have slide'register clearance about the key lugs 5 in push button-operation. Depressing of the button i4 against the action of the spring 8 is-limited by the lower or free ends of these inwardly arced or channel portions-I Estriking the bottom 6. g

j The'bottom I2- of the body I, besides thru the opening ID, has a pair of screw openings I6 (Fig. 5); Sielf tappingscrews II' thru terminals I8, spring arms I9, insulation disk 20, into the openings I6 in the body I thereby clamp inward over hang portions 2I- between the disk 2!] and the bottom I2. The lesser pitch for the screwsII,

than for the screw 9,'invo1ves less installingstrain upon the body I and is reliable for maintaining assembly. The overhangZI has clearance regions yieldable holding fingers 23 in partial seats 24 .of the body side 2 in their extent toward the rim 3.

The insulation disk 28 in its clamp direction toward the bottom face I2 of the body I, engages the rim 2I, but is spaced from the screws I 'I sufliciently to avoid current leakage to the fingers 23, affording the anchorage as thrust into a socket in locating the unit in position for use.

Primarily the unit comprises the plastic housing or body I and the plastic push button I4, each of insulation material. There is a third insulation element, the disk 20. The reinforcing sleeve or eyelet I4 in the spring chamber is not in circuit relation with the stem 9. This chamber above the floor I is a non-electric current region. While the stem 9 extends thru this floor, its electric current eiiective region is at its head II for current flow between the arms I9 of the respective terminals. The screws H which assemble the terminals I8 with the body I are clear 3 of the shell 2|, 23, for the rim 2| does not extend sufliciently inward under the disk to engage the screws I I.

The insulation disk 20 locates the spring arms I9 of the terminals in such proximity to the screw head II that the slide travel of the screw 9 thru the opening III contacts and slightly hows the spring arms I 9 and forms a short circuit bridge at the normal clearance before the stops I5 strike the bottom 4. The disk 29 has openings 26 for the self-tapping screws I1, and adjacent thereto openings 21 for key prongs 28 of the terminals I8 to anchor the terminals against turning as tothe body I. Completion of the anchoring is due to recesses 29 in the face I2 adjacent the openings I6. With the terminal I8 seated about the screw I1, against the spring arm I9, the terminal prong 28 enters the opening 21 in a recess or seat 29. Each of the spring arms I9 has an opening 30 for a selftapping screw II mounting the terminal I8 therewith, so that the key or prong 28 projects thru an opening 3I in the arm I9 to engage with a seat 29 in the face of the body I, completing the anchoring against turning as to the body I.

When formed of plastic, th molded plastic body I, is in association with the complementarily molded plastic plunger I3, I4, forming the major structure and all insulation material.

The unit is readily adapted to assembly line production. The several parts are nested. A press operation may thrust the main screw 9 into the assembly with the button head I4, prior to the placing of the terminals I8 with their spring arms I9, the clamp insulation disk 20 against the rim of the finger-shell 2|, 23, for the self-tapping screws IT to complete the unit.

What is claimed and it is desired to secure by Letters Patent is:

1. An electric switch insulation body adapted to be thrust into a socket to determine in-use location therefor, an insulation disk, said body being embraced by an annular series of yieldable frictional holding fingers, there being an inward overhang mounting rim for the fingers, a pair of switch terminals, and switch terminal mounting means clamping the disk and overhang with the body for directly assembling the fin ers with the body.

2. An electric switch insulation body, an annular series of relatively yieldable spring fingers embracing the body connected by a rim over an end of the body, an insulation disk against the rim, and holding means extending thru the disk and clear of the rim into the body for assembling the fingers with the body.

3. An electric switch insulation cup body having an outward annular rim, said cup interior having key configuration. electric switch terminals connected to the body bottom, an insulation plunger insertable in the cup of the body and having complementary key configuration to that of the cup for holding the plunger and body against relative rotation during relative reciprocation, and switch terminal closing means mounted on the plunger and spaced from the insulation key configurations.

4. An electric switch of the push button type embodying an insulation body with an open top and a wall extending therefrom to form a chamber with an inwardly extending bottom flange having an opening therethru concentric with the open top, said top having an outwardly extending integral flange parallel with the bottom flange and adapted to form a limit stop upon insertion of the body in a mounting opening therefor, an insulation push member closure for the open top, said member having an insulation extension boss into the chamber of less diameter than the closure, a switch-closing conductor head having an integral stem slidable thru the opening in the bottom flange and extending into the chamber to engage the extension 'b0ss,a compression helical spring embracing the boss and thereby insulation spaced from the stem, said spring in its extent between the chamber-exposed sides of the push member and bottom flange urging the head against the outside of the bottom flange, and independent oppositely directed conductor arms assembled with the body flange outwardly from the chamber, said arms being disposed normally clear of the head and approximately parallel to the bottom flange, whereby thrusting of the push member may mov the head to close a switch circuit between said arms.

FREDERICK VON VOIGTLANDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 534,547 Burchell Feb. 19, 1895 748,409 McLean Dec, 29, 1903 1,303,634 Cadieux May 13, 1919 1,699,491 Miller Jan. 15, 1929 1,944,522 Miller et a1. Jan. 23, 1934 2,423,387 Johnson July 1, 1947

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