US2382996A - Combination contact and terminal for electric switches - Google Patents

Description

Aug. 2.1, 1945. E. N* JAcoBl 2,382,996

COMBINATION CONTACT AND TERMINAL FOR ELECTRIC `SWITCHFS Filed July 19, 1944 Ill Patented Aug. 2l, 1945 PATENT t oFFlcE COMBINATION CONTACT AND TERMINAL FOR ELECTRIC SWITCHES Edward N. Jacobi, Milwaukee, Wis., assis-nor to Briggs 8a Stratton Corporation, Milwaukee, Wis., a corporation of Delaware Application July 19, 1944, Serial No. 545,627

Claims.

This invention `relates to electric switches and refers particularly to small automotive switches which are generally, though not necessarily, actuated by key controlled lock mechanisms. Switches of this type are illustrated in Patents Nos. 1,842,451 and 1,912,982, issued to E. N. Jacobi. January 26, .1932 and June 6, i933, respectively.

While the invention broadly concerns switches 'of this type, it has particularreference to the wire terminals andstationary contacts thereof. One of the features of these switches is that the switch mechanism is 'mountedin the inner end portion .of a cylindrical lock body or casing adapted to besecured to a panel by a clamping nut threaded .and the ,attachment of the wires still lie fully -within the circumference of the lock body or casing so that the clamping nut may be freely applied or removed .after the .wires have been secured in position. This, of course, is a decided advantage vin that it facilitates the installation of the switches. `B y virtue of `this construction the vattachment of the wires may be effected under circumstances considerably more convenient than if they had to'be connected after the switch was mounted in its position of use. I

Another object of this invention is to provide a wire terminal .of the character described which not only provides .animproved manner of secur- -ing the wire leads to the stationary contact members of the switch, but also serves to secure the stationary contacts in position on the terminal In view of the relatively small size of switches of `this ,type and the consequently small travel of the movable contactor the heads of the stationary contact members must necessarily be small to insure the proper electrical clearance. Still .these contact members should have enlarged heads to hold the members against being pulled out of the terminal head. As a result, the Shanks of the stationary contact members, which protrude through the terminal head, are of limited diam- (ci. zoo-iss) ent invention to obviate this disadvantage through the provision of means not limited by the diameter of the head on the contact member for gripping the wire. s 5 With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly stood that such changes in the precise embodiment of the hereindlsclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised foi-,the practical application of the principles thereof, and in which:

Figure 1 is a side4 view of an electric switch embodying this invention, a part thereof being broken away and in section;

Figure 2. is an exploded perspective view illustrating the various parts of the combination stationary contact and wire terminal;

Figure 3 `isi-an enlarged longitudinal sectional view through the terminal illustrating the same in its completely assembled state; and

Figure 4 is a view illustrating the manner in which the terminals are clinched to effect permanent securement of the contacts and wires.

Referring now particularly'to the accompanying drawing in which like numerals indicate like parts, the numeral i designates the casing or body oi a lock switch within which the switch mechanism indicated generally by the numeral 6 is mounted to be `actuated by a rotatable tumbler controlled cylinder 'i upon the insertion of a proper key 8.

The front end 0 of the casing is'i'langed to pro- 40 videa' shoulder which bears against the front face of the mounting panel (not shown) and thus f cooperates with a clamping nut Iii to mount the casing or body on the panel. The nut I0 is adapted to be passed over the inner rear end cf the casing or body.

The switch mechanism comprises a movable contactor Il connected with the lock cylinder 'l in any conventional manner to be rotated to and from a position bridging a pair of stationary contacts i2. The stationary contacts are mounted on an insulated terminal head i3 which is secured in and closes the open rear end of the casing or body.

The two stationary contacts, which are ideneter. It is therefore another object of the prestical, are provided by the heads I4 of headed cydeflned by the appended claims, it being underlindrical pins or contact members I5. The shank of each of these members is tubular and projects through a hole I 6 in the terminal head. 'Ihe inner end of this hole is counterbored to receive the head I 4 so that the contact surface rises but slightly above the inner face of the terminal head. The heads I4 also secure the pins or contact members I5 against being pulled out of the terminal head.

Telescoped over the tubular shank of each of the pins or contact members I5 is a sleeve I1. One end of this sleeve bears rrly against the outer face of the insulated terminal head and its opposite end portion projects a substantial distance beyond the pin or contact member I 5. Inserted into each assembled sleeve and pin is an insulated wire I8, the insulation having been removed from the extreme end portion of the wire which enters the tubular shank of the pin or contact member I5, while the insulation extends into the sleeve I1.

Sleeve I I may be counterbored to a larger diameter in order to take thicker insulation diameter of Wire I8. Sleeve I'I may also be reduced by turning to a smaller diameter at the neck 20, so that the metal at this point may be corrugated properly to produce a rm clinch and an A intimate Contact with the wire.

The assembled sleeves, pins and wires are transversely deformed by being clinched between complementary dies I9 of an arbor press, as shown in Figure 4. In this manner a localized portion 20 of each terminal assembly is deformed from its normal round transverse shape into an oval shape thus effecting a mutual interlocking relationship which iirmly locks the parts together and secures the contact members or pins 5 in position on the terminal head.

In the clinching operation caremust be taken that the sleeve bears solidly against the terminal head, and to insurev a solid grip the ends of the sleeves are preferably beveled to provide sharp edges whichrbite into the terminal head during the clinching operation. The outer ends of the contact members or pins I5 are also preferably beveled to provide sharp edges to bite into the ends of the insulation on the wires.

The outermost ends of the sleeves, which are also beveled and have sharp edges, are clinched inwardly around their entire perimeters as at 2| to grip the insulation and hold the same against shifting.

From the foregoing description, taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art that this invention provides a simple but highly effective terminal construction for small electric switches and that it provides a strong, solid connection between the wire and stationary contact of the switch without in anywise interfering with the passage of the clamping nut onto and oil' of the casing or body. Thus it is possible to attach adequate lengths of wire to the switch at the factory and thereby eliminate the difculties attending the attachment of wires after a switch of this type is mounted in place.

What I claim as my invention is:

1. A combination contact and wire terminal for electric switches comprising: an insulated terminal head having a hole therethrough; a headed contact member having an elongated tubular shank received in the hole and projecting beyond the terminal head to provide a wire terminal, the head on the Contact member holding said Contact member against being pulled through the terminal head; a wire lead having its end portion received in the tubular shank; a sleeve fitted over the shank of the contact member and bearing iirmly against the insulated terminal` head; and said sleeve and tubular shank being transversely clinched to the extent that the wire within the shank of the contact is deformed and secured to the contact member.

2. In an electric switch: an insulated terminal head having a hole therethrough; a contact member having a tubular shank projecting through said hole; means for limiting endwise movement of the contact member in one direction; a wire lead having its end received in the tubular shank; and a sleeve iitted over the shank of the contact member and bearing rmly against the terminal head; said sleeve, shank and wire being transversely clinched into a deformed cross sectional shape whereby said parts are iirmly secured against movement with respect to each other with the sleeve bearing against the terminal head to secure the contact member in place, and a good electrical connection is established between the contact member and the wire.

3. In an electrical switch: an insulated terminal head having a hole therethrough with a counterbore opening to one face; a headed contact member having a ltubular cylindrical shank projecting through said hole with its head disposed in the counterbore; a metal sleeve telescoped over the tubular shank of the contact member and bearing rmly against the insulated head; and a. wire having its end portion received in the tubular shank, said sleeve, tubular shank and wire having portions thereof transversely deformed into interiitting, substantially oval shaped sections so that said parts are secured against relative movement and the contact member is held assembled with the terminal head.

4; In an electric switch: a substantially cylindrical body within which the switch mechanism is located, said body having an externally threaded portion and a shoulder; a clamping nut passed over the inner end of the body and threaded on said threaded portion to cooperate with the shoulder in mounting the switch on a panel; an insulated terminal head closing the inner end of the body, said terminal head having spaced holes therethrough; stationary contact members having tubular shanks projecting through said holes but with all parts thereof lying well within the circumference of the cylindrical body; means to prevent pulling the contact members out through said holes, the inner ends of the contact members providing the stationary contacts of the switch; wire leads having bare end portions received in the tubular shanks of the stationary contact members; and sleeves telescoped over said shanks of the contact members and bearing rmly against the outer face of the terminal head, said sleeves, tubular shanks and wires having portions thereof transversely clinched into mutually interlocking condition to secure said parts together and iix the contact members to the terminal head with all portions of the assemblies lying well within the circumference of the switch body so that the nut may be applied and removed after the wires are secured in place.

5. A combination stationary contact and terminal comprising: an insulated terminal head having a hole therethrough; a tubular pin member received in the hole; ahead on one end of said pin member engaging the terminal head at one side thereof to limit movement of the pin member axially in o'ne direction; a metal sleeve telescope onto the tubular pin member with one end bearing firmly against the other side 01' the insulated head and its other end portion projecting beyond the pin member; an insulated Wire having a bared end portion disposed within the tubular pin member with its insulation entering the metal sleeve; said sleeve. tubular pin member and wire being transversely deformed at a. localized area to clinch said parts into mutually interlocking relationship and secure the pin member to the terminal head, and the outer extremity of the sleeve being clinched inwardb1 to grip the insulation of the wire.

EDWARD N. JACOBI.

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