US2469274A

US2469274A - Electrical switch

Info

Publication number: US2469274A
Application number: US752033A
Authority: US
Inventors: Rein Charles
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-06-03
Filing date: 1947-06-03
Publication date: 1949-05-03
Anticipated expiration: 1966-05-03

Description

May 3, 1949. c. REIN 2,469,274

ELECTRICAL SWITCH Filed June 3, 1947 2 Sheets-Sheet 2 @www :1mm Ulli 66 ATTORNEYS WLM/EMM www Patented May 3, 1949 UNITED STATES PATENT oFFlcE ELECTRICAL swrrcn Charles Rein, Scarsdale, N. Y. k Application J une 3, 1947, Serial No. 752,033

7 Claims.

The present invention relates to electrical switches and, more particularly, to switches adapted to signal the closure thereof, such as by visual means.

A general object of the present invention is to provide such an electrical switrch which is of sturdy but simple construction, readily adapted to economical commercial production and which may be easily manipulated eiiciently to close or make an electrical circuit and, if desired, to connect thereto simultaneously another electrical circuit. f

A more specilc object of the present invention is to provide in such apparatus a manually-slidable means of certain unique construction which is adapted effectively .to close a main electrical circuit in the manner of a push button switch while being capable of being selectively latched in circuit-opening or break and circuit-closing or make positions, and which may be, if desired, utilized selectively to connect and disconnect to the main circuit an auxiliary electrical circuit with simultaneously closure and opening of the former. Y

Another object of the present invention is to provide such switch apparatus which includes signal means, such as a visual signal light, which maybe operated automatically, effectively to indicate when manipulation of a manually-slidable means is closing an electrical circuit.

A further object of the invention is to provide an embodiment of such switch structure which may be utilized as a gear shift grasp knob for an automobile to make readily accessible to the driver an easily manipulated, circuit-controlling switch for electrical operation of certain apparatus which is adapted to function normally in association with gear shifting procedures.

Still another object of the invention is the provision of a certain structural embodiment of the device which is readily constructed and permits efficient use and operation thereof.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts, which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in con- (Cl. 20o- 167) nection with the accompanying drawing, in which:

Fig. 1 is an elevational view from one side of a preferred unit embodiment of the present invention showing the same mounted upon certain manually-operated lever structure whereby the unit may serve as la grasp knob:

Fig. 2 is a view similar to Fig. 1 taken from the opposite side thereof;

Fig. 3 is an enlarged elevational section, with parts broken away, of the structure shown in Figs. 1 and 2, and taken substantially on line 3-3 of Fig. 4;

Fig. 4 is an enlarged top plan view, with parts broken away. of the structure shown in Figs. 1, 2 and 3; 1

Fig. 5 is a transverse sectional view taken substantially on line l-B of Fig. 3, with the lamp socket omitted; i

Fig. 6 is an exploded elevation of the structure shown in Figs. 3, 4 and 5;

Fig. 7 is a perspective view of certain relatively fixed contact structure of the apparatus shown in Figs. 3, 4, 5 and 6, before being distorted to give spring action;

Fig. 8 is a perspective view of certain slidable saddle contact structure of the apparatus shown in Figs. 3, 4 and 6, adapted to close the contacts of Fig. 7;

Fig. 9 is a perspective view of certain block structure adapted to operate the saddle contact structure fo Fig. 8; and

Fig. 10 is a simple circuit diagram of the apparatus of Figs. 1 to 6 inclusive, indicating one possible use of .that embodiment of the invention.

Prior to the present invention it has been proposed to provide grasp knobs for gear shift levers of automobiles with certain switch structures to permit manual control of certain electrical circuits, such as those designed for holding brakes applied; and to equip them with signal lights intended visually to indicate when those electrical circuits are open and closed. However, those structures in the main have been of such character as to make switch manipulations by certain drivers diflicult and evenfaulty while the drivers were occupied simultaneously with gear shifting procedures, a time when such switch manipulations are frequently desired. Further, the structural features of such apparatus were, in many cases, needlessly complex'a'nd unadapted to economical commercial production. These and other undesirable features are effectively minimized or substantially eliminated by the present invention.

Referring to the drawings like numerals identify similar parts throughout and, as will be seen therefrom, an embodiment of the invention comprises a base structure including a metallic sleeve or socket member I2 adapted to be press tted, threadably mounted or secured by a set screw I2 upon the end of a lever I4 which, if desired, and as shown, may be hollow in order to provide an internal passage for circuit wires of the switch unit; but of course, may be solid, in which case the circuit wires will be located externally thereof. For passage of circuit wires to the interior of the hollow lever I4, the latter may have a pair of holes I5, I5 in the side thereof substantially aligned with a pair of holes I5, Il in the side of the metallic socket or sleeve I2. Preferably, the far end of sleeve I2 is substantially closed by an end wall I1 to form a socket member thereof, with that end wall having a recess Il internally thereof. A projecting boss I9 is provided on the end wall |1 externally thereof, located substantially co-axially of the socket sleeve l2.

The base structure also includes a sleeve 20, preferably of suitable insulating material, such as a molded plastic, and provided intermediate its ends at 2| with a transversely extending partition to dene a socket 22 in which the metallic socket sleeve I2 is press fitted or otherwise secured. For this securement the end of the boss I9 beyond the partition 2| may, if desired, be equipped with suitable means to hold the metallic sleeve I2 in the socket 22 of the insulating sleeve 2li and such means may comprise a nut threadably engaged upon external threads on the end of boss I9 projecting beyond the partition 2|, or the boss may have that projecting end swelled or turned over to provide a motion-limiting shoulder, such as by spinning, peeping or the like.

AThe sleeve of insulating material has a socket 22 in the far end 24 thereof with its bottom defined by the partition 2|, and the boss i9 preferably extends from the latter co-axially into the bottom portion of that socket, as shown in Fig 3. The far end 24 of the insulating sleeve 2|) preferably has a circumferentially extending groove 25 in its end face, and a pair of

counterbored holes

25, 25 preferably extend longitudinally from the groove 25 to longitudinally extending,

external grooves

21, 21 each of which communicates with one of the holes I5 in the metallic socket 2| by means of a hole 28. so as to provide for passage of a pair of electrical conducting means from the circumferential groove 25 to the interior of the lever |4. As shown ln Fig. 2, and indicated in Figs. 4 and 5, the longitudinally extending

holes

26, 25 with their aligned

grooves

28, 25 in the insulating sleeve 20 are preferably circumferentially spaced apart by an appreciable radial angle.

In each of the longitudinally extending, counterbored holes 25 is mounted a plug jack female g or socket member 29 which has a shank portion 30 located in the smaller diameter portion of the counterbored hole. The far end 2| of shank 20 extends through a hole in and beyond a C-shaped or substantially semi-circular metallic terminal contact 22 and is riveted or peened over, as shown in Fig. 3, securely to hold the parts together and to anchor the terminal contact to the far end of the insulating sleeve. As will be seen from Figs. 4, 5 and '7, each of the two female or

socket members

29, 25 of the plug j ack structures anchors one of a pair of the

contact terminals

22, 22 in the groove 25 of the end 24 of insulating sleeve 25, with those contact terminals arranged in spaced apart opposed relation. Each C-shaped contact 22 has a pair of

ends

22 and 24, with the

ends

22, 22 anchored by the

female sockets

25, 25 to the insulating sleeve 20. Preferably, the

unanchored ends

24, 24 of the

terminal contacts

22, 22 are distorted outwardly out of the plane of the bottom face of the circumferential groove 25, as shown in Fig. 3, and natural resilience thereof spring-biases them to those positions so as to assure good electrical contact with a bridging member when moved inwardly to physical contact therewith. If desired, the unanchored end 24 of one of the contacts 22 may be distorted outwardly farther than the other to provide break of a. main circuit before disconnection of an auxiliary circuit from one side of the main circuit, as explained hereinafter. The pair of

contacts

22, 22 constitute relatively fixed, spaced apart, circuit terminals for a main electrical circuit, which may include a pair of flexible and insulated circuit wires 25. 25 each having fixed on the end thereof a male member 25 plugged into for electrical contact with one of a pair of female members 25 of the plug jacks, as shown in Fig. 3.

An elongated, substantially xed. guide member 21 is mounted in the socket 22 of insulating sleeve 20, preferably by being press fitted thereinto. Guide member 21 is preferably in the form of a cylindrical lamp socket sleeve of metallic material having good electrical conductivity and serves as one terminal of an auxiliary electrical circuit. For this purpose the outer end of the sleeve 21 is preferably provided with a pair of diametrically opposed keyhole slots 2l, 25 to receive a pair of diametrically opposed pins 25, l5 on the sides of a cylindrical base terminal 44 of an electric light bulb 4 I, which is adapted to serve as a signal lamp, as explained hereinafter. The cylindrical sleeve 21 circumambiently surrounds a terminal pin 42 which projects through an axial hole 22 in the boss Il, with a headed end 44 of the pin seated in the recess Il in the bottom of metallic socket sleeve I2, for good electrical contact therewith and for grounding connection of the auxiliary circuit. The terminal pin 42 has a contact head 45 on the far end thereof to make electrical contact with the central button terminal 45 of the lamp 4|, and a helical spring 41 preferably is arranged about the pin between its head 45 and the boss I5 to spring bias the pin outwardly while permitting sliding inward movement thereof in the hole 42 when the lamp is mounted into the socket sleeve 21, securely to hold the lamp in mounted position.

Preferably, the sleeve 20 of insulating material is circumferentially rabbeted on the external surface thereof at 42 to provide a seat for an end of a casing shell 45 telescoped over the far end 24 of that insulating sleeve. The casing shell 42 preferably has a portion thereof of light-transmitting character and, for this purpose, its outer end 5l preferably is closed of! by means of a cap 5I of transparent or translucent material, such as translucent plastic. The light-transmitting cap 5| preferably has a cylindrical portion 52 rabbeted to be received within and to provide a shoulder 52 to seat upon the far end of the casing shell 45. as shown in Fig. 3. It will be seen from Figs. 3 and 6 that the metallic socket sleeve I2, insulating sleeve 25, the lamp socket sleeve 21, the pin terminal 42 and the casing shell 4l are all preferably co-axially arranged with the casing shell, light-transmitting cap 5I and the in- 8 sulating sleeve 2l providing together a casing means for enclosure of the other parts, and with the casing shell spaced laterally outward away from the socket sleeve to provide a cylindrical space therebetween in` which the pair of

terminal contacts

32, 32 are arranged and mounted.

Circuit closure means or make-and-break mechanism is mounted within the casing means or interior of the casing shell 49 and, preferably. comprises a curved contact means or saddle 54 of metallic material' of good electrican conductivity. Preferably, as shown in Figs. 3, 4 and 6 and 8, the saddle 54 includes a curved base plate 55 slidably mounted upon the elongated, substantially fixed, guide member or lamp socket sleeve 31 for longitudinal reciprocative action or sliding motion, and also for the purpose of making electrical connection therebetween. The saddle 54 of the sliding contact means has, on the inward end thereof, a pair of :circumferentially spaced apart and substantially radially extending ears or

fingers

55, 55, and on its outward end a similar single ear or finger 51. The contact means also preferably includes a block 55, preferably of insulating material, such as molded plastic, seated upon and carried by the saddle 54 between the pair of

fingers

55, 55 and the single finger 51'. Preferably, the block 55 has on one end thereof a pair of radially spaced apart projections or lugs 59, 59 between which the finger 51 of the saddle 54 seats when the block is seated upon the saddle, to prevent relative rotation.

Preferably, saddle 54 is provided with a thru hole 50 and there is substantially aligned therewith an internally threaded hole 5I in block 58. The internaly threaded hole 5i in block 55 threadably engages the externally threaded shank 52 of manually-engageable means or manual button 53 for fixation to the block. The externally threaded shank 52 of button 53 is projected through a hole, preferably an elongated, longitudinally extending slot 54, in the side of the casing shell 49 from the exterior of that shell to the interior thereof for the threaded fixation to the block 58, so that the button may be slid or reciprocatcd longitudinally or axially of the unit construction for sliding motion of the saddle contact 54 along the socket sleeve 31 between two positions.

Preferably, automatic latch means are incorporated in the switch structure temporarily to hold the slidable contact means in either of its make and break positions. For this purpose there is preferably provided a spring-biased detent between the slidable contact means and the substantially fixed guide member 31 which constitutes the lamp socket. Preferably this detent means comprises a helical biasing spring 55, mounted in a bore 5'5 in the button shank 52 and a detent ball 51, located in the aligned holes 6U and 5|, respectively extending through the saddle 54 and the block 55. For cooperation withv` the detent ball 51 the elongated, substantially fixed, guide member or lamp socket sleeve 31 preferably is provided with a pair of longitudinally or axially spaced apart

notches

55 and 69 into which the spring-biased ball is adapted alternately to snap, temporarily to hold the contact means in either of its two positions. It will be understood however, that any well known automatic latch means or spring-biased detent means may be provided for or mounted between the contact means and the lamp socket sleeve to serve that purpose. Of course, although button 53 is shown to be made of insulating mate- 6 rial, such as molded plastic. it may be formed, if desired, of metallic material, with an insulating washer located between parts of the latch mechanism, such as between spring 55 and ball 51.

In use and operation of the embodiment of the invention shown by way of example in the drawings, the same may be employed as a grasp knob for the gear shift lever of an automobile, and mounted in the manner suggested in Figs. 1, 2 and 3, with one signal lamp terminal 45 grounded by means of pin 42 and metallic socket l2 to the usual metallic gear shift lever I4. 'I'he

electrical conductors

35, 35 may be connected into a main electrical circuit for switch control thereof, such as by connecting one of those conductors to the hot or positive side of the ignition system of the automobile, preferably at the ignition switch. The other electrical conductor 35 will then b e connected to the electrically operable device or accessory intended to be controlled by that switch, such as to one side of the electrical circuit of a solenoid valve in a brake holding device of the general type indicated in the Sacks et al. U. S. Patent No. 2,224,747 with the other side of the circuit of the latter grounded. The circuit of this accessory may be considered to be a main electrical circuit.

In operation of this preferred embodiment an auxiliary circuit is provided for particular use as a signalling means to indicate when this switch means is closing the main circuit. For this purpose the construction provides means for connecting the auxiliary circuit, comprising the signal lamp 4|, to the main circuit and thus to the positive or hot side of the ignition system simultaneously with closure of the main circuit. Since the contact saddle 54 is slidably mounted upon the lamp socket sleeve 31, serving as the positive side terminal of the auxiliary signaling circuit, electrical connection therebetween is had at all times. v

, If the control button 63 is slid or pushed longitudinally or axially inward toward lever I4 or down, as viewed in Fig. 3, the spring-biased detent ball 61 will be forced out of the notch 58 defining the break positions of the switch means to snap into the notch 59 defining the make position of the switch means. In the latter position the ears or

fingers

55, 56 on the contactsaddle 54 are brought into secure electrical contact with the spaced apart

terminal contacts

32, 32 connected into the main circuit and, as a result, the main circuit will be closed. Simultaneously with closure of the main circuit the contact saddle v54 makes electrical connection between that main circuit and the auxiliary signaling circuit via the lamp socket sleeve 31 and lamp base terminal 40, so as to connect that side of the auxiliary or signal lamp circuit to the hot side of the ignition circuit. Thus, the signal lamp 4| will be lighted to indicate closure of the main circuit at the

contacts

32, 32. When the control button 53 is then slid back to the break position, with the detent ball 51 snapped into the notch 58 the contact saddle 54 will be free from contact with the main

circuit terminal contacts

32, 32, as shown in Fig. 3, and with simultaneous disconnection of the auxiliary signaling circuit from the hot side of the ignition system. As a result, the light goes out to indicate that the main circuit has been broken at the

contacts

32, 32 therein.

The casing structure of the embodiment of the present invention, shown in the drawings, is of such shape and size as to provide a convenient and comfortable grasp knob for the gear shift lever. When so employed, the slidable or reciprocable control button 63 is conveniently accessible to the thumb of the automobile driver as he grasps the gear shift lever knob. This is desirable, since when the unit of the present invention is employed to control the circuit of a brake holder, the energlzation of the latter is usually desired when the automobile is being brought to a stop, while stopping and in starting up from a i'ull stop, which actions are usually attended by gear shifting.

It will be understood that although the device of the present invention is particularly adapted to such use in an automobile, it is not limited thereto since the main circuit to be closed by the switch means may be any electrical circuit, preferably low tension, adapted to switch closure, and the auxiliary circuit may be any electrical circuit to be associated with the particular main circuit with simultaneous connection of one side of the former to the latter upon closure oi the latter. Of course, for such other uses the auxiliary circuit may be a signaling circuit for visual indication of closure of the main circuit switch or it may be another type of auxiliary electrical circuit. It will thus be seen that the objects set forth above and those made apparent from the preceding description are eiilciently attained and since certain changes may be made in the above construction and diil'erent embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An electrical switch unit comprising, in combination; relatively fixed, spaced apart, main circuit terminal contacts for make and break of one side of a main circuit which may have its other side suitably and otherwise completed; an elongated, substantially nxed, electrically conducting member forming a terminal for one side of an auxiliary circuit which may have its other side suitably and otherwise connected to the completed side of the main circuit; a casing arranged circumambiently of said terminal member and spaced laterally therefrom; and longitudinally reciprocable contact means slidably mounted between said member and casing adapted in one position to bridge said relatively fixed contacts for main circuit make and simultaneously with contact of said auxiliary circuit terminal member to connect the latter to one side of the main circuit at the make-and-break contacts oi' the latter, said reciprocable contact means being adapted in anothemposition to disengage said make-and-break contacts for main circuit break and to disconnect from the latter said auxiliary circuit terminal member; whereby the main and auxiliary circuits may be closed and opened simultaneously.

2. An electrical switch unit comprising, in combination; a pair of relatively fixed, spaced apart, main circuit terminal contacts for make and break of one side of a main circuit which may have its other side suitably and otherwise completed; an elongated, substantially xed, electric lamp socket forming a terminal for one side of an auxiliary signal circuit which may have its other side suitably and otherwise connected to the cornpleted side of the main circuit; a casing shell arranged circumambiently of said socket and spaced laterally therefrom; and longitudinally reciprocable contact means slidably mounted between said socket and shell adapted in one position to bridge said relatively fixed contacts for main circuit make and simultaneously with contact of said socket to connect the latter to one side of the main circuit at the make-and-break contacts of the latter, said reciprocable contact means being adapted in a second position to disengage said make-and-break contacts to break the main circuit and to disconnect from the latter said socket: whereby a signal lamp in said socket may indicate closed and opened conditioning of the main circuit.

3. An electrical switch unit adapted to serve as a grasp knob for the end of a lever comprising, in combination; a metallic base structure serving as means to mount the unit on such lever and as a grounding connection; an elongated, metallic electric lamp socket sleeve: means supporting said lamp socket sleeve on and insulating it from said base structure; casing means arranged circumambiently of said lamp socket sleeve and spaced laterally therefrom, said casing means having a hole therein and having at least a portion of light-transmitting character; a pair of spaced apart, circuit terminal contacts mounted on and insulated from said base structure and arranged betweensaid socket sleeve and said casing means; longitudinally reciprocable contact means slidably mounted within said casing means upon said lamp socket sleeve adapted in a make position to bridge said circuit terminal contacts and simultaneously to connect said lamp socket sleeve thereto, said reciprocable contact means being adapted in another position of break to disconnect said lamp socket sleeve from said contacts and disconnect the latter from each other; and manually-engageable means mounted on said reciprocable contact means and projecting through the hole in the casing for external access to slide longitudinally of said casing contact means between its make and break positions.

4. An electrical switch unit adapted to serve as a grasp knob for the end of a lever comprising, in combination; a metallic base structure serving as means to mount the unit on such lever and as a grounding connection; an elongated, metallic electric lamp socket sleeve; means supporting said lamp socket sleeve on and insulating it from said base structure; casing means arranged circumambiently of said lamp socket sleeve and spaced laterally therefrom, said casing means having a hole therein and having at leastwa portion of light-transmitting character; a pair of spaced apart, circuit terminal contacts mounted on and insulated from said base structure and arranged between said lamp socket sleeve and said casing means; longitudinally reciprocable contact means slidably mounted within said casing means upon said lamp socket sleeve adapted in a make position to bridge said circuit terminal contacts and simultaneously to connect said lamp socket sleeve thereto, said reciprocable contact means being adapted in another position of break to disconnect said lamp socket sleeve from said contacts and disconnect the latter from each other; manually-engageable means mounted on said reciprocable contact means and projecting through the hole in the casing for external access to slide longitudinally of said casing said contact means between its make and break positions; and means automatically to latch said reciprocable contact means temporarily in either of its make and break positions.

5. An electrical switch unit adapted to serve as a grasp knob for the end of a lever comprising, in combination; a metallic base structure serving as means to mount the unit on such lever and as a grounding connection; an elongated, metallic electric lamp socket sleeve; means supporting said lamp socket sleeve on and insulating it from said base structure; casing means arranged circumambiently of said lamp socket sleeve and spaced laterally therefrom, said casing means having a longitudinally extending slot therein and having at least a portion of lighttransmitting character; a pair of spaced apart, circuit terminal contacts mounted on and insulated from said base structure and arranged between said lamp socket sleeve and said casing means; longitudinally reciprocable contact means slidably mounted within said casing means upon said lamp socket sleeve adapted in a make position to bridge said circuit terminal contacts and simultaneously to connect said socket sleeve thereto, said reciprocable contact means being adapted in another position of break to disconnect said lamp socket sleeve from said contacts and disconnect the latter from each other; manually-engageable means mounted on said reciprocable contact means and projecting through the slot in the casing for external access to slide v longitudinally of said casing said reciprocable contact means between its make and break positions; and spring-biased detent means mounted between said lamp socket sleeve and said reciprocable contact means temporarily to hold the latter relative to the former selectively in the circuit make a-nd break positions.

6. An electrical switch unit adapted to serve as a grasp knob for the end of a lever comprising, in combination; a metallic base structure serving as means to mount the unit on such lever and as a grounding connection; an elongated, metallic, electric lamp socket sleeve having a pair of longitudinally spaced notches in the exterior side thereof; means supporting said lamp socket sleeve on and insulating it from said base structure, casing means arranged circumambiently of said lamp socket sleeve and spaced laterally therefrom, said casing means having an elongated slot therein extending longitudinally thereof and having at least a portion of light-transmitting character; a pair of spaced apart, circuit terminal contacts mounted on and insulated from said base structure and arranged between said lamp socket sleeve and said casing means; longitudinally reciprocable contact means slidably mounted within said casing means upon said lamp socket sleeve adapted in a make position to bridge said circuit terminal contacts and simultaneously to connect said socket sleeve thereto, said reciprocable contact means being adapted in another position of break to disconnect said lamp socket sleeve from said contacts and disconnect the latter from each other, said reciprocable contact means having a hole extending transversely therethrough; a manual button mounted through the slot in said casing for sliding motion back and forth in the latter longitudinally thereof and fixed in the hole in said reciprocable contact means; and a spring.. biased detent in the contact means hole to coopcrate with the notches in said lamp socket sleeve temporarily to hold said reciprocable contact means selectively in the circuit make and break positions.

7. An electrical switch unit adapted to serve as a grasp knob for the end of a lever comprising, in combination; a metallic base structure serving as means to mount the unit on such lever and as a grounding connection; an elongated, metallic, electric lamp socket sleeve adapted to receive and retain the base of an electric lamp and to serve as one terminal connection therefor, said sleeve having a pair of longitudinally spaced apart notches in the exterior side thereof; means providing for electrical connection between the usual button terminal of an electric lamp within the socket and connected to said metallic base structure; means supporting said lamp socket sleeve on and insulating it from said base structure circumambiently of the button terminal connecting means; a cylindrical casing shell arranged substantially co-axially about said lamp socket sleeve and spaced laterally therefrom, said casing shell having a longitudinally extending slot in the side thereof opposite the notches in said lamp socket sleeve; a light-transmitting cap closing the end of said sleeve opposite the end mounted on said metallic base structure; a pair of spaced apart, circuit terminal contacts mounted on and insulated from said base structure and arranged between said lamp socket sleeve and said casing shell; a saddle of electrically conductive, metallic material slidably mounted on said lamp socket sleeve for motion longitudinally thereof and located within said shell adapted selectively to bridge said contacts for circuit make with simultaneous connection of said socket sleeve thereto when slid inwardly of said casing shell to one position and to disengage said contacts for circuit break and disconnect said lamp socket sleeve therefrom when slid outwardly in said shell to another position; a block of insulating material mounted on said saddle within said shell for sliding said saddle between its make and break positions and insulating it from said shell; said saddle and block having aligned holes extending transversely therethrough; a manual button extending through the slot in said shell from the exterior of the latter and secured in the hole in said block; a detent ball mounted in the aligned holes in said saddle and block for alternate engagement in the notches in said lamp socket sleeve; and a, biasing spring mounted between said button and said detent ball to bias the latter into notch engagement temporarily to hold said bridging saddle in either of its make and break positions.

CHARLES REIN.

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

UNITED STATES PATENTS Number- Name Date 1,935,467 Beer et al Nov. 14, 1933 2,263,754 Batcheller Nov. 25, 1941 2,347,874 Bluemle May 2, 1944 2,430,189 Schellman Nov. 4, 1947 FOREIGN PATENTS Number Country Date 423,957 Great Britain Feb. 12, 1935