Electric switch

Feb. 10, 1953

2,628,293

J. H. WILLIAMS ET AL

ELECTRIC SWITCH

Filed Jan. 9, 1952

<img file="US2628293A_D0001.tif" />

Patented Feb. 10, 1953

2,628,293

UNITED STATES PATENT OFFICE

2,628,293

ELECTRIC SWITCH

John. H. Williams, Barrington, and Edward J. Mastney, Berwyn, Ill., assignors to Oak Mfg. Co., a corporation of Illinois

Application January 9,1952, Serial No. 265,584

Claims. (Cl. 200—51.09) ear 25 to which may be anchored one end of coil spring 26.

Rigidly attached to stub shaft 24 is switch operating member 27 consisting of an irregularly5 shaped piece. Member 27 has ear 28 for supporting the hooked end 29 of coil spring 26. The other end of coil spring 26, indicated by numeral 31, is looped over ear 25 so that the coil spring biases part 27 to the position shown in Figure 1. 10 Member 27 has edge portion 32 termmating in tip portion 33 bearing against in~ide surface 34 of front portion 11 of the frame. It is understood that coil spring 39 presses member 27 so that tip 33 is in the position shown.

Part 13 of the frame is large enough to support stub shaft 24. As seen in Figures 2 and 4, member 27 is disposed between sides 12 and 13 of the frame. Thus, actuating portion 32 and tip portion 33 of member 27 comes behind slot 15 and is 20 normally engaged by prong 18 of the plug when inserted. Member 27 has concave part 35 adjacent to actuating portion 32 so that when prong 18 is inserted, the tip of the prong will ride along actuating part 32 of member 27, this 25 actuating part functioning as a cam surface and finally permits the tip of prong 18 to enter concave region 35 of member 27. In this position, as shown in Figure 3, member 27 has been turned again-t the bias of spring 30 counter-clockwise 30 through a predetermined angle, and member 27 and the prong will be stable.

Secured to stub shaft 24 is portion 37 of a rotary switch section generally indicated by numeral 38. Switch section 38 has stator 39 rigidly 35 secured to the frame as by staking ears 40 and 4 i extending from side 13 of the frame. Switch section 37 may be of any desired construction and is conveniently one section of switch as disclosed, for example, in Patent 2,186,949, issued on 40 January 16, 1940. Instead of one switch section, a plurality of sections may be provided.

The particular switching arrangement and contact arrangement in the switch section is not important, as far as this invention is con45 cerned. However, such switch sections have appreciable drag and thus the entire actuating mechanism for the switch presents a substantial load upon prong ! 8 of the plug. As is well known, most plugs have prongs 18 and 19 disposed in ₅₀ a rubber molding or in a suitable flexible mount so that some play of the prongs is permitted.

The tendency of one prong to move with respect to the other prong thus makes it difficult for a plug of this character to operate the mech55 anism so far described. In order to support prong 18 against displacement from the desired path of travel during switch operation, side 13 is punched out to provide strips 41 and 42 generally extending toward each other, as seen in Figure 2, but 6° having the opposing edges spaced from each other

This invention relates to an electric switch and particularly to a construction fol· operating a rotary switch through a predetermined angle of movement.

In certain types of apparatus, particularly portable radio receivers of the type adapted for operation either from a battery or from a power line, it is customary to provide a switch construction for changing from one type of operation to the other. Such receivers have a line cord terminating in a conventional two-prong plug which may be inserted into a conventional wall-type socket for connection to a 110 volt power line. When the receiver is to be used on battery, the line p’ug is inserted into a special receptacle by the receiver. This receptacle includes a switch which is operated by one of the prongs of the plug to change the internal circuits of the receiver so that battery operation is possible.

This invention provides a construction which is an improvement upon such switch mechanism.

In order that the invention may be understood, it will be explained in connection with the drawing wherein:

Figure 1 is a side elevation of a construction embodying the present invention, an operating plug being shown ready for insertion into the switch;

Figure 2 is a front view on line 2—2 of Figure 1;

Figure 3 is a side view similar to Figure 1 but showing the mechanism in a different position with the plug fully inserted;

Figure 4 is a top view along line 4—4 of Figure 3.

The construction embodying the present invention has frame generally indicated by numeral I0 and consisting of front portion 11 and side portions 12 and 13, respectively. Front portion 11 of the frame is provided with slots 15 and 16, these slots being transverse to the long dimension of front portion I ί and being spaced and dimensioned to accommodate prongs 18 and 19 of plug 20.

Slot 16 and prong 19 have no function as far as switch operation is concerned. It is understood that it is immaterial which particular prong of plug 20 is used, since the construction is not polarized. Thus, plug 29 may be turned around so that prong 19 simply refers to the lower· prong.

Slot 15 has the right portion thereof, as seen in Figure 2, enlarged to form a transverse slot 21, slots 15 and 2 i together forming a generally T-shaped composite slot.

Part 12 of the frame extends for a sufficient distance to provide part 23 for supporting one end of a short stub shaft 24 forming part of a rotary switch. Part 23 of the frame also has

2,628,293 rear surface of the front part of the frame, spring means for biasing said member so that the cam portion is at the rear surface of the front portion of said frame, said cam portion lying rearwardly in line with said slot, and spaced supporting members carried by one of said frame side portions, said supporting members extending rearwardly of the front frame portion and forming a channel which is a prolongation of said slot whereby a pronged member inserted into said slot to engage the cam portion for turning said member will have support, switching means having stationary and movable contact portions, means for securing the stationary contact portion to said frame and means for coupling said rotary member to said movable contact portion.

2. The structure according to claim 1, wherein said member has a cut-out adjacent the cam surface into which the prong end may rest when the 20 prong is fully inserted.

JOHN H. WILLIAMS.

EDWARD J. MASTNEY.

No references cited.

to provide a gap. The gap between supporting members 41 and 42 is substantially equal to the width of slot 15 and permits prong 18 to slide between these two supporting members.

As is evident from Figures 1 and 3, supporting 5 members 41 and 42 extend for a substantial distance along side 13 in back of front part I i of the frame so that the major portion of the length of prong 18 is supported against movement toward or away from prong 19. Thus the load upon 10 prong 18 will have no tendency to bend or damage the actuating prong of the plug upon insertion into the switch mechanism.

It is understood that the frame and the various parts thereof, such as the sides, spring and the 15 like, are made of steel or other sheet metal.