US1118623A - Electric-lamp socket. - Google Patents

Description

R. B. BENJAMIN ELECTRIC LAMP SOCKET.

APPLICATION FILED JAN.

Patented Nov. 24, 1914.

* support is subject to. vibration.

OFFICE.

REUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS, ASSIGNOR T BENJAMIN ELECTRIC MFG. COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELECTRIC-LAMP SOCKET.

Specification of Letters Patent.

Patented Nov. 24, 1914.

Application filed January 31, 1912. Serial No. 674,537.

To all whom it may concern Be it known that I, REUBEN B. BENJAMIN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Electric-Lamp Sockets, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention pertains to electric lamp sockets such as are intended to be used on shipboard, on cars, on busy streets, in factories, and in other places where the socket The vibrations to which the socket is subjected when used in such places as those noted above, have the effect of shaking the lamp loose in the socket; and the frequent necessity of attending to sockets the lamps in which have thus become loose, has been the subject of much annoyance, especially in series systems, where more work than the mere tightening of the lamp must usually be done.

\Vith the above conditions in view, it is an object of my invention to provide a socket which will be convenient in use and which will be of such a nature that a lamp contained therein cannot be shaken loose by vibration.

It is a further object of my invention to produce a socket in which, while means are provided for preventing the lamp from being shaken loose, the lamp may be introduced and removed without the performance of other operations than the ordinary ones of screwing the lamp in or out.

My invention is described in the following specification and shown in the accompanying drawings, as applied to a lamp socket oi the type disclosed in my co-pending application Serial No. 590,502, filed November 3, 1910; it may be embodied in other devices, however, within the scope of the appended claims.

In the drawings: Figure 1 is an elevational view, in section, showing a lamp socket having my invention applied thereto; Fig. 2 is a plan of the lower base member; Fig. 3 is a sectional inverted plan, the section being taken on the line 3-3 of Fig. 1; and the parts being shown in the position which they assume when a lamp is being withdrawn from the socket; Fig. 4 is a similar view to Fig. 3, but showing the .position of the parts when a lamp is not present in the socket; and Fig. 5 is a detail perspective view of the threaded lamp-terminal-engaging contact.

Referring now to the drawings, 14; indicates a collar adapted to be secured to a conduit or the like and having external screw threads for receiving a bracket 21, which clamps a casing-shade 12 in position upon the collar, as shown. The bracket .21 carries a base consisting of an upper member 19 and a lower member 35, these parts being secured together and to the bracket by means of screws 37 which pass through the members 19 and 35 and enter the bracket. The upper member 19 carries, on the lower face thereof, a center contact 2i and a pair of binding terminals 31 and the latter being therefore accessible when the lower member is removed from the upper. The lower member 35 is formed with a central aperture 38 in which is contained a threaded sleeve which forms the outer lam 'i-terminal-engaging contact. The sleeve 30 is secured to the member by means of a rivet 43 passing through a lug extend ing laterally from the sleeve, and is provided with a contact member -11 which makes conneetion with the binding terminal 25 when the members 19 and are secured together. The parts above described are connected and arranged in a like manner to similar parts in the device described in my co-pending application Serial No. 590,502.

in this embodiment of my invention, the threaded contact 39 is cut away at its lower end throughout a portion of its circumference. the out being made along the line of the thread and leaving a lug 4-5 (Fig. 5), which acts as a guide for leading the threads oi. the lamp end into those of the contact 39. A spiral spring 46 is wrapped upon the threaded contact 39 in the thread groove thereof, the inner end 47 of the spring being held against movement by being bent outward so as to enter a recess 48 in the wall oi the aperture 38. The spring 46 follows the thread groove of the contact 39 and emerges therefrom at the outer cut-away portion of the contact. being carried, in' the embodiinent shown, beyond the contact for a distance of somewhat less than one turn, thus forming an extension 49. The extension as is of a reduced diameter, so that it will closely engage in the thread of the lamp end when a lamp is screwed into the socket. The end 50 of the extension 49 is bent outward as shown in Figs. 3 and 4 so as to enter a recess 51 formed in the wall of the aperture 38, the parts being of such dimen sions that the end 50 of extension lies adjacent to, but normally does not touch the wall of the recess (Fig. 4:).

The operation of the device is as follows: Vvhen a lamp is to be inserted into the socket, its end is pushed up against the outer end of the threaded contact 39, the extension 49 giving way and allowing the lug 45 to spring into the thread groove of the lamp end, whereby the lamp end is properly guided into the threaded contact 89. The lamp is then screwed up into the contact 39, the effect of such movement be ing that, owing to the frictional engagement of the extension 49 with the lamp end, the spring is unwound to a small extent, whereby the friction between the extension 49 of the spring and the lamp end is diminished. The lamp may thus be inserted into the socket with very little effort. The extension 49, bearing upon the lamp end, effectually prevents the lamp from being shaken loose in the socket by the effect of any vibrations to which the socket may be subjected. When, however, it is desired to remove the lamp, this may be effected by unscrewing it in the ordinary manner, the first effect of the unscrewing movement being that. the spring 46 is tightenedupon the threaded contact 89, and the extension 49 is tightened upon the lamp end. Tf the tightening of the spring end 49 upon the lamp end were permitted to continue, it would be difficult, if not impossible, to unscrew the lamp from the contact 39. Tt will be noted, however, that, as the spring tightens, the end 50 of the extension L9 moves in a contraclockwise direction. After the spring has tightened to a certain extent, the end 50 engages against the stop formed by the wall of the recess 51, and is thereby prevented from further movement. The extension 49 cannot thereafter contract about the lamp end and the lamp can therefore be unscrewed from the contact 39. It will be noted, therefore, that the stop formed by the wall of the recess 51 has the effect of limit ing the contraction of the extension 49 about the lamp end.

t will be seen that the above construction precludes any chance of the lamp becoming shaken loose in the socket; and does so while maintaining a simple and inexpensive construction. It is further to be noted that the lamp may be inserted into, and withdrawn from, the socket by the ordinary operations of screwing in and screwing out, and without any other operations being necessary.

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

1. Tu an electric lamp socket, the combination with a threaded lamp receiving shell, of a coiled spring wrapped about said shell and having a portion of its coil of reduced diameter and extendinginto said shell to closely engage the lamp when the lamp is screwed into said. shell.

2. Tn an electric lamp socket for the reception of lamps having threaded ends, the combination with a lamp receiving shell, of a coiled spring wrapped about said shell and having one end thereof of reduced diameter and extending into said shell to closely engage the lamp when the lamp is screwed into the shell, and a stop in a position to be engaged by the end of said spring after the lamp has been moved in adirection to withdraw the same from said device.

3. In an electric lamp socket forthe reception of lamps having threaded ends, the combination with a threaded lamp-receiving shell, of a coil spring wrapped about said shell and having the outer end thereof extending beyond the outer end of said shell, such extended end of said coil spring being of a reduced diameter, whereby the extended end of said coil spring is entered and closely engaged by thelamp end when a lamp is screwed into said shell.

4. Tn an electric lamp socket for the reception of lamps having threaded ends, the combination with a threaded lamp-receiving 10o shell having a guiding lug extending from the outer end thereof, of a coil spring wrapped about said shell and having the outer end thereof extending beyond the outer end of said shell, such. extended end of said coil spring being of a reduced diameter, whereby the extended end of said coil spring is entered and closely engaged by the lamp end when a lamp is screwed into said shell, and said lug guides said lamp end into said shell.

5'. Tn an electric lamp socket for the reception of lamps having threaded ends, the combination with a threaded lamp-receiving shell, of a coil spring wrapped about said shell and having the outer end thereof extending beyond the outer end of said shell, such extended end of said coil spring being of a reduced diameter, whereby the extended end of said coil spring is entered and closely engaged by the lamp end when a lamp is screwed into said shell, and means for engaging the outer' end of said coil ,spring after the lamp has been turned in a direction to unscrew it from said shell, whereby said engaging means limits the contraction of the extended end of said coil spring about the lamp end.

6. Tn an electric lamp socket for the reception of lamps having threaded ends, a

base having a chamber formed therein, a portion of said base being formed, within said chamber, with a stop, a center lampterminal-engaging contact disposed centrally with respect to said chamber, a threaded lamp receiving shell disposed in said chamber, a coil spring surrounding said shell and having the outer part thereof extending beyond the outer end of said shell and having the end thereof adjacent to, but out of engage ment with, said stop, such extended part of said coil spring being of a reduced diameter, whereby the extended part of said coil spring is entered and closely engaged by the lam end when a lamp is screwed into said shel, and said stop limits the contraction of such extended part about the lamp end during the removal of the lamp from the socket.

In witness whereof, I have hereunto subscribed my name in the presence of two Witnesses.

REUBEN B. BENJAMIN. Witnesses:

MABEL REYNOLDS, C. E. KANE.

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