US1878387A - Electric lamp socket - Google Patents

Description

Sept. 20, 1932. G. H. E'LWELL ELECTRIC LAMP SOCKET Filed Oct. 10. 1927 Patented Sept. 20, I932 UNITED STATES enonen HENRY ELWELL, on NEW HAVEN, CONNECTICUT, AssIeNon To THE ennis'r MANUFACTURING COMPANY, on NEW HAVE CONNECTICUT, a eonrona'rIo or CONNECTICUT ELECTRIC LAMP sooner Application filed October 10, 1927. Serial 110.225.192. I I

The. invention relates to improvements in electric lamp sockets adaptedto receive an incandescent lamp bulb and to lock the same therein against theft. The art discloses variedforms of theft proof electric lamp sockets of which many require some special constructionof the metal base of the lamp bulb, or the breaking of the lamprbulb upon its removal, but "the invention herein disclosed adapts the improved lamp socket to receive and to locktherein the ordinary incandescent lamp bulb releasable .only under certain conditions. The applicant is also aware that improvements in the art have already extended to electric lamp sockets of this character which include either a rotatable screw-shell adapted to be locked against rotation upon the authorized placing and removal of the lampjbulb, or a locking band or cover with an inturned flange to lockingly engage with the annular edge of the metal base of the lamp bulb. The rotatable screw-shell'and the locking band both have their advantages, and it is the intention of this invention to. so employ principles suggested, perhaps, by each in the new construction of a novel theftproof electric lamp socket that will further develop the art in that direction, and therefore the objects of the invention are to provide an'electric lamp socket carrying a rotatable member adapted to lockingly engage the annular edge of the metal base of an ordinary electric lamp bulb and rotat'etherewith until the bulb is fully in place within the screw-shell contact and then automatically become locked against reversed rotation; and to provide for the removal of the bulb only when the electric circuit embracing the particular fixture is opened by means of the throwing off the circuit switch.

The following is the description of an embodiment of the invention the construction of which may be varied within the scope of what may hereinafter be claimed without a departing from the spirit or modifying any of'the advantages of the invention. Reference being hadto the accompanying drawing one sheet) the Figure 1 is an upright elevation of an improved-socket without a casing,but witha metal base of an electric lamp bulbi'lo'cked thereto; Figure 2 is "a v similaru'priglrtelevation butin a different rotary position and including the. insulation" lining illustrated incross-section; Figured is an upright elevation ofthe'screw-shell'and rotatable memberin. assoclated relatlon; and

Figure 4 is a cross-sectional view of the socket at the line 44 p of Figure 1',' 1ll ustrat1 'ng the rotatable member unlocking means.

Referring more particularly'to the drawing, in which similar parts are similarly numbered', thescrew-shell 1 is fixed to the 'body of insulationQ in any desired manner;- The rotatable locking member Sis ofsuch'screwshell'formation as to ads; t it for meshins its rolled-in thread with the exterior presentation of the rolled-in thread of the screw-shell j 1, as bestillustrated byfFigure 3. The inner extremity of the rotatable locking member 3 is provided with an unthreaded annular portion 4 carrying the spring arm 5 inwardly"- presenting the catch 6 for locking engagement wlth an edge 7 bounding an openlng -8 in an unthreaded portion 9 of the sorew shell 1. This opening 8 ordinarily exists in screw a shell formation already known to the art, but if desired a special opening8inay be provided for the purpose above explained.- The outer extremity of the rotatable lockingmem ber 3 is so constructed as-to' assume the'form 0f a-series of spring arms, preferably more than two, each arm presenting an inturned flange portion 10, as best illustrated by Figi ure 3, for locking engagement with the annular edge 11 of the metal base 12 of anordinary incandescent lamp, asillustrated inFig I ures 1 and 2. The unthreaded portion'4 of the rotatable memberis provided, substantially diametrically opposite the catch 6 and the edge 7 in'locked relation, with a small elongated perforation 13; A similar perforation in the unthreaded portion 9 of the screw-shell is made unnecessary bythe usual opening therein corresponding with and located opposite the opening 8 and extending sufliciently tobe used as illustrated by Fig 'ure '4 and as later explained The floor 14 of the lamp receiving socket to whichthe shell 1 is rigidlysecured'isiprovidedwithithe guide 1.5 to positively direct the course of a needle 16 inserted within the perforation 18, and a convenient way in which to construct this guide is by rolling it up out of the screw-shell bottom as illustrated by Figure 4. The course of the needle 16 as directed by the guide 15,'an integralpart of the screw-shell 1, insuresthe "engagement of the needle with the contact 17 an integral part of the switch.

contact bar 21 depending therefrom, the otherswitch bar 19"depe'nding fromthe cen-' ter 'cohta'ct"20 andbeingparallel-to and in spaced relation with the switch contact bar 21, as illustrated in dotted line by the Figure 1, and the catch 6 inlocked postion.. It is obvious that when the rotatable member 3 is 1'0- tated upon the screw-shell to a degree greater than-is illustrated by'TFigure 3 the lamp bulb.

maybe insertedtherein so that the 'inturned flange portion '10: mayengage the edge '11 of; the 'metallamp g'bZtSQ 1-2. ,The bulb may be screwedintoythe screw-shell as the rotatable member; is turnedtherewith first by the hand andathen'icarried by th'e gripfl'ofv the spring arms around-the annular edgev 11 until the lamp is electrically connected and the spring catch 6 falls over the edge-7;;as' illustrated by Figure 1; V The lamp 1 bulb? thereby becomes automatically locked within the electric lamp socket for any attemptedunauthorized removal thereof is-pre'vented by the flange por-.

tions '10 blockin'gthe displacement of the annularedge-l ltof the lamp base'andithe inability of the rotatable.lockingmember 3 to turn with the bulb byreason? ofvits locked condi-' tion with the screw-shell as above explained. Anyfimanipulation ofuthe flanges in an attempt to release the lamp bulb is frustrated by the fact that these spring arms 5 are protected by the snu girelatio'n thereto of the inshlationsleeve-18-illustrated by the Figure 2, associated: with the electric lamp socket in a manner well-known to'the art}; The electric circuit" switch, controlling the fixtures from thecatch-6,enabling the pushing of the spring arm- 5" sufliciently' to disengage the catch 6 from the edge 7 while a reversed rotation of the lamp bulb carrying the rotatable member thus freed is. then limited only by the needle 16 within the elongated perforation 13. The needle mayiimmediately' be withdrawn; for the continued -rotati"on ofthe lamp bulb carries th'e rotatable member 3- With its catch 6,

thef latteri immediately" riding out of the plane of the opening-8. With "the switch boardi locked up within an enclosure or lo- ,catedfzin menu-0a place'iand therefore not readilyaccessible to the unauthorized person it makes it difficult, if not impossible, for an electric lamp bulb to be wrongfully removed; for any attempt to remove a lamp bulb locked within this improved socket without first having thrown off the general switch would endangerthe manipulator should'hethrust a needle into the perforation 13 while'the'screwshell and the center lamp contact are electri cally alive. By providin with which to release" the catch j 6, substitute of insulation material, such'as a toothpick, can'be -e'mployed to defeat the purpose of this' invention.

What'I claimi's:' 1.;An electric lamp socket comprisingt a a h id 15 or. the entrance therein of a fragile steel needle screw-shellto receive the. threaded base ofa lamp, a second-screw shell threaded upon said first shelland 'carrying'flanged portions for holding. engagements with an annularedge of the threaded base, and means providedby reverse rotationq both shells toflock the shells against relative I 2; An electric lamp .socket comprising, a

screw-"shelllto receive the threaded base of a lamp,-said shellhaving an opening-in its cylindrical wall,v and a second screw-shell with an annular edge o-ftthe lamp base, and'a threaded uponvthe firsti-shell and carrying flanged portions for holding(engagements.

catchnmember. carried by thesecond shell for f engagement within the opening to: lock the shells'against reverse rotation.

3. An electric lamp socket comprising a 7' screw-shellto receiveithe threaded base. of a lamp,-said shell havingoppositely positioned openings' in its cylindrical wall, a second screw-shellthreaded uponthe first shellx and t carrying 'flanged'portions for holding engagements with an annular edge ofthe lamp,

base,- a catch memberpcarried by the second shell-for engagement within one of the openingstolocktheshells against'relativereverse :rotation, and; means provided vby the socketto safely dislodgewthe catch member electric-current cut off. i

4. electric lamp socket comprising a screw shell for'rec'eiving the threaded metal 1 base-ofza lamp-ya sleeve of insulation surv from its locking' engagement only with the rounding said-screw-shell', the screw-shell having oppositely positioned openings in its cylindrical wall; contacts within tl'lB Sl'l8ll I and insulated one from the other and from the shell, each contact having afixed depending switchbar; a guide having apassage therethroughprovidedfbythe shell,-the passage beingzaligned with one-of the contacts; a

second screw-shell threaded' upon the first shell, the secondshell having an elongated opening in its cylindrical 'with a screw-shellopening; flanged portions wall toregister I integrally provided by the second shellforholding engagements'with an annular edge I Of an inserted metal baseof a lamp, thesleeve it? i of insulation co-operating to maintain the holding engagements; a catch member carried by the second shell for engagement within one of the openings of the first shell to lock the shells against relative reverse rotation; and means to safely dislodge the catch from its engagement with the opening only with the electric current cut oil, said means comprising a fragile needle adapted for entrance within openings of the second and first shells and into the guide passage to bethereby directed to and contacted with one of the contacts to establish between the shells and such contact a short circuit, the shells and such contact being Within the electrical circuit.

GEORGE HENRY ELWELL.

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