US1054946A - Self-locking lamp-socket. - Google Patents

Description

W. A. STACEY.

SELF LOGKING LAMP SOCKET.

APPLIOATION FILED MAY 16. 1912.

1,054,946. Patented Mar; 4, 1913.

liYZ'VZZO/J Mammy,

" fl m M5? UNITED srATEs PATENT OFFICE.

WILLIAM .A. STACEY, OF CHICAGO, ILLINOIS.

SELF-LOCKING LAMP-SOCKET.

Specification of Letters Patent. Application filed May 16, 1912. Serial- NO. 697,703.

Patented Mar. 4, 1913.

To all whom it may concern:

Be it known thatI, WILLIAM A. Smear, a citizen of the United States, residing at Chicago, county of Cook, State of Illinois,

.have invented a certain new and-useful Improvement in Self-Locking Lamp-Sockets, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, ref erence being had to the accompanyin drawings, which form a part of the speci cation.

My invention relates to lamp sockets and I has for its object to produce a simple and tion of the casing being broken away at the base of thelamp;-Fig. 2 isaside view on a somewhat larger scale of the socket itself with the lamp removed, the casing being omitted; Fig. 3- is-a view similar to Fig. 2, showin a lamp screwed into the socket; Fig. 4 1s a section' through the lamp-receiving end of the socket, with thecasing in positiomand Fig. 5 is a. section on an enarged scale approximately on line of" viduality which it may be desired to give to Fig. 4.

Referrin to the drawing, 1 represents the insulating lock or base of a lamp socket,

this member having any usual or suitable construction. Connected with the member 1 i is a coiled spring 2 which forms the receiving member for the screw-threaded base. of a lamp. The spring is made of wire small enough to lie within the valleys of a thread on a lamp base the diameter of the wire being less than the pitch'of the thread. The spring. 2 is so formed that normally its coils tend to lie close together, making it necessary to place the spring under tension in order to separate the coils.- The result of this construction, assuming that one end of the springis fastenedto the member 1 and the other. end is: left free,- is that when a lamp is screwed into the socket, the' coils of the spring are spread so as to cause them to follow the threads on the lamp and the tension of the spring causes the coils to take a firm grip on the threads on the lamp. Consequently, when it is attempted to unscrew the lamp, the friction between the threads and the coils of the spring is suflicient to lock the two together so that a turning movement of the lamp causesthe coils of the springto become wrapped more tightly about the base of the lamp. Consequently, the lamp cannot again be unscrewed unless some means is; provided for holding the spring so that Its effective diameter cannot be decreased. I have provided means whereby thespring may be held against a wrapping movement around the base of the lamp when some one having a proper key or the like desires to remove the lamp. For this purpose I have turned up thefree end 3 of the spring so that it lies outside of the spring and transverse to its coils and have arranged-on the usual casing or housing 4.- a suitable adjustable stop which may be moved in in front of the upturned end so as to prevent motion thereof in the direction to cause the spring to wrap itself upon the base of the lamp when the lamp is unscrewed. In the arrangement shown, I have arranged on one side of the member 4.- a projecting sleeve or nipple 5 in which is fitted an insulating bushing 6 having at the center a metal sleeve 7 screw threaded interiorly. Screw-threaded into the sleeve 7 is a post or stud 8 having its outer end 9 shaped to receive a suitable key; the shape of the member 9 depending upon the degree of indithe key necessary to turn the post or'stud. The parts are so arranged thatin the normal position of rest of the spring,-that'is, 1

a position when there is no lamp in the socket,the upturned end 3 lies just at the side of the inner end of the post or stud so that when the post or stud isscrew ed in it forms a stop against which the upturned end will strike when the free end of the spring is carried in the direction to decrease the effective internal diameter of the spring,-that is, in the direction in which the free end of the spring is carried when the socket. I

The operation is as follows: Normally the post or stud is screwed out far enough to permit the free end of the spring to move it is attempted to unscrew a lamp fromi manner.

.struction in which a spring-like past the inner end of the post or stud. Then when a lamp is screwed into the socket, the coils of the spring take a tight grip thereon and, if it is attempted to'unscrew the lamp, the free end of the spring is carried around past the inner end of the post or studand the spring is wrapped tightly upon the base. of the lamp; in other words, the lamp is automatically locked to the socket by the mere act of screwing it into the socket. It

will thus be seen that it is possible'for anyone to screw a lamp into a socket, because no key or other tool is required for first placing the socket in the proper condition; but it some unauthorized person attempts to remove the lamp he Wlll find that it is securelylocked in place. In order to remove a lamp, some one having a proper key must screw the stud or post inwardly so as to make"it efiective as a stop for the free end of the spring, whereupon the lamp may be unscrewed as from any other socket. the lamp has been removed, the stud or post is screwed back to its original position and the socket is ready to receive another lamp and lock it in place. In order to make it more difficult to tamper with the socket so as to permitan unauthorized person to remove a. lamp, I prefer to make the screwthreads 10 between the sleeve 7 and the post 8 left handed so that the post must be turned in the opposite direction from that in which one would naturally turn it to screw it in.

The stationary end of the spring may be fixed to the insulating base in any suitable A very satisfactory arrangement, and one which requires existing devices, consists in providing the base 1 with a short screw-threaded shell 11,-this bein in fact a piece of the usual screw;threade socket or a similar piece;- screwing the inner end of the spring into the member 11 and then soldering it thereto. This arrangement permits standard terminals to be used and at the same time alines the spring and holds it firmly in place.

While I have illustrated the normal idle condition of the spring as that in which the coils touch each other, I do not desire to be limited to this particular arrangement because my invention contemplates any concoil is caused to take enough of a hold upon a member screwed into it to cause the coil to -wrap itself upon the member when it is atthe latter. Further- I have illustrated only one specific for efiecting the release of a lamp,

tempted to unscrew more, means but I do not desire to be limited to the particular structural details so illustrated. In

After but little change in otherwords, while I have illustrated and described in detail a single preferred embodiment of my invention, I do not desire to be limited to the specific details so illustrated and described; but intend to cover all forms and arrangements which come within the terms of the definitions of my invention constituting the appended claims.

I claim:

1. In a device of the character described, a supporting base, a helical coil secured at one end to said member and having its other end free, and a movable stop adapted to engage with said free end.

2. In a a support, a helix secured at one end to said support and comprising one or more turns adapted to engage in the valleys of a thread on a lamp, and adjustable holding means for the other end of the helix.

. 3. In a device of the character described,

device of the character described, 1

support and comprising one or more turns adapted to engage in the valleys of a thread on a lamp, and a movable holding device arranged to be moved into the free end of the helix.

4. In a device of the character described, a support,a helix secured at one end to said support and comprising a plurality of turns adapted to lie within the valleys of a thread on a lamp, the normal pitch of the helix being less than the pitch of said thread, the free end of the helix side and transverse to the coils, justable stop arranged to be moved into the path of said free end.

5. In a. device of the character described, asupport, a helix secured at one end to said support and comprising a plurality of turns adapted to lie within the valleys of a thread on a lamp, the normal pitch of the helix be ing less than the pitch of said thread, the free end of the helix being bent laterally beside andtransverse to the coils, a casing extending around the helix, and an adjustable stop carried by the casing in position to engage with said free end.

6. In a device of the character described, a support including a short screw-threaded sleeve, a helix having one or more of its turns fitting intothe threads in said sleeve at one end and having a tree portion comprising one or more turns projecting beyond the sleeve.

In testimony whereof, I sign this specification in the presence of two witnesses.

WILLIAM A. STACEY.

Witnesses:

WM. F. FREUDENREIGH, RUBY V. Burners...

engagement with being bent laterally beand an ad-

Images