US2796497A - Electric switch with terminal assembly especially adapted for connection to printed circuits - Google Patents

Description

111118 1957 w. A. BARDEN 2,796,497

ELECTRIC SWITCH WITH TERMINAL ASSEMBLY ESPECIALLY ADAPTED FOR CONNECTION TO PRINTED CIRCUITS Filed March 14, 1956 United States Patent Wayne A. Barden, Elkhart, Ind., assignor to Chicago Telephone Supply Corporation, Elkhart, Ind a corporation of Indiana Application March 14, 1956, Serial No. 571,479

4 Claims. (Cl.- 200-166) This invention relates to electric switches of the type used in radio and television receivers and generally mounted on the back of a variable resistor to be operable by the control shaft of the resistor, as in the combination control of the copending application Serial No. 403,401, filed January 11, 1954, by Mervin B. Arisman, to which the present invention is closely related.

The object of the invention is to provide a simple, inexpensive way of adapting such a switch for convenient connection into a printed circuit.

A more specific object of the invention is to provide an inexpensive terminal assembly securable to the back of the switch, which not only adapts the switch to easy and quick connection into a printed circuit, without necessitating any change in the switch from the design and construction found desirable through years of experience, but in addition is so constructed that it suitably insulates the terminals by which the switch is connected in the printed circuit from the metal cover or housing of the switch.

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 defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

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

Figure 1 is a side view of a combination resistor and switch of the type to which this invention pertains equipped with the terminal assembly of this invention and mounted on a printed circuit panel;

Figure 2 is a perspective view of the terminal assembly per se; and

Figure 3 is a rear view of the switch with the terminal assembly mounted thereon and as in Figure 1, showing the switch mounted on the printed circuit panel.

Referring now particularly to the accompanying drawing, the numeral 5 designates generally a combination control consisting of a variable resistor 6 and an electric switch 7 arranged in tandem with the switch mounted on the back of the resistor so that both components are operable by a common control shaft 8. The control is adapted to be mounted upon a supporting panel 9 on which the various circuit leads 10 are printed. The mounting of the control upon the panel 9 is eifected by means of a bracket 11 fixed to the front of the resistor 6 and provided with spaced apart legs 12 which embrace the control and have a plug in or snap in engagement with the panel 9. The copending application, Serial No. 403,401, filed January 11, 1954, by Mervin B. Arisman, describes this mounting bracket in greater detail. It should be noted that in the mounting of the control the tion of the terminal members.

terminals 13 (only two of which are shown), of the variable resistor protrude through the mounting panel 9 to be connected to their respective leads of the printed circuit.

The instrumentalities of the resistor and also of the switch form no part of this invention and therefore have not been illustrated. It is suflicient to observe that the switch is contained within a housing comprising a flat end wall 14 of insulating material and a cylindrical metal side wall 15 having an inturned flange 16 overlying the outer rear face of the end wall 14. The stationary contacts 17 of the switch are mounted on the inner face of the end wall 14 and have terminal extensions 13 projecting rearwardly through and beyond the end wall 14. The switch may be of the type forming the subject matter of Patent No. 2,660,634, issued November24, 1953, and if it is of the double pole single throw type, there are of course, four stationary switch contacts, and hence four terminal extensions 18.

Flatwise overlying the rear end wall 14 is the terminal assembly of this invention indicated generally by the numeral 19. This terminal assembly comprises a plate of insulating material 20 of a size to cover the entire rear face of the switch and preferably has an inverted U shape so as to have a round upper end and a straight bottom edge 21. The height of the plate is approximately one and one-half times the diameter of the switch housing and its width is substantially equal to the diameter of the switch housing.

The plate 20 is relatively thin and flexible and has a row of oblong holes 22 along its bottom edge 21 equispaced from one another and from the edge 21; and that part of the plate which overlies the rear of the switch has a series of slots or holes 23 through which the terminal extensions 18 pass. The holes 22 and 23 are paired, and since there are four terminal extensions, there are four pair of holes. For each pair there is a terminal member 24 stamped from sheet metal. Two of these terminal members are short and two are long. Each has a head 25 and a stem 26, the ends of which are narrower than the rest of the stem to provide prongs 27.

These terminal members overlie the rear surface of the plate with their heads surrounding the holes 23 and their stems passing through the oblong holes 22. The heads of the terminal members have holes 25 which register with the holes 23 and have the terminal extensions received therein. Soldered connections 28 secure the terminal members to the extensions and thereby hold the terminal assembly to the switch with the insulating plate interposed between the terminal members and the inturned flange of the metal side wall. Those portions of the stems of the terminal members which lie at the inner face of the plate because of the passage of the stems through the holes 22, are far enough from the side of the switch housing to assure adequate electrical clearance, and to make certain of this condition the two middle holes 22 are shorter than the outer holes.

The projection of the stems 26 through the holes 22 flexes the insulating plate slightly and in so doing achieves a secure connection between the stem and the plate to assure good support for the prongs 27 which project beyond the bottom edge 21 of the plate to enter holes in the printed circuit panel 9 when the switch is mounted thereon.

Attention is directed to the roughly P-shaped forma- This gives the individual terminal members adequate area at their head portions 'which are soldered to the terminal extensions and still enables maintaining sufiicient electrical clearance between adjacent terminal members by having the heads of the shorter middle members embraced by the longer outer members. This shape also permits the terminal members to be formed as identical stampings one for the outer members and one for the middle members.

From the foregoing description taken in connection with the accompanying drawing it will be readily'apparent to those skilled in this art that this invention provides a very inexpensive but entirely practicable man- 'ner of connecting an electric switch of the type used in radio and television receivers into a printed circuit, and that its adaptation to this new technique involves no departure from well established design principles for switches of the type here under consideration.

What I claim as my invention is:

1. An electric switch having a housing comprising a flat end wall of insulating material and a metal side wall provided with an inturned flange overlying the outer face of the marginal portion of the end wall, and having contacts mounted on the inner face of the end wall with terminal extensions projecting through the end wall, characterized by a terminal assembly to facilitate connecting the switch into a circuit printed on a mounting panel, said terminal assembly comprising: a plate of insulating material flatwise overlying the outer face of said end wall and the inturned flange with a portion of the plate projecting beyond the side wall of the switch housing and terminating in an edge which edge is remote from the side wall and contiguous to the surface of the printed circuit panel when the switch is in position thereon, said plate having holes in line with the terminal extensions of the contacts and through which said extensions pass and having a row of other holes adjacent to I said edge of the plate; a flat stamped sheet metal terminal member for each of said terminal extensions, each having a head portion overlying the outer face of the plate and provided with a hole through which the terminal extension passes and a stem portion passing through one of said row of holes and overlying the inner face of the plate; a soldered connection between each terminal extension and the head portion of the adjacent terminal member; and prongs on the ends of the stem portions of the terminal members parallel with one another and projecting beyond said edge of the plate to protrude into holes in the mounting panel when the switch is mounted on the plate with said edge contiguous thereto. a

2. The structure of claim 1 further characterized by the fact that the holes in the plate through which the stem portions of the terminal members pass are elongated in the direction of the stem portions, and by the fact that the plate is flexed crosswise of the elongated holes so that the tension due to its flexure causes the ends of the holes to grip the stem portions.

3. Thestructure of claim 2 further characterized by the fact that the terminal members are flat throughout their entire extent.

4. The structure of claim 3 further characterized by the fact that there are four terminal members, all of which are roughly P shaped in formation, with two identical short members and two identical long members, the long terminal members being spaced apart on the plate and having their head portions facing one another, and the short terminal members lying between the stem portions of the long terminal members and having their head portions facing away from one another.

References Cited in the file of this patent UNITED STATES PATENTS 1,362,553 Bagge Dec. 14, 1920 1,784,290 Jacobi Dec. 9, 1930 2,474,988 Sargrove July 5, 1949 2,492,236 Mydlil Dec. 27, 1949 OTHER REFERENCES Electronics Magazine, March 1954, page 108.

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