US1209626A - Current connection for electric lamps. - Google Patents

Description

H. R. SARGENT. CURRENT CONNEC'HON FOR ELECTRIC LAMPS.

APPLICATION FILED DEC.26. I914.

Patented Dec. 19, 1916.

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HDWARD R. SARGENT, 01F SCHENEGTADY NEW YORK, ASSIGNOR TO ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CURRENT GONNEC'IION FUR ELECTRIC LAMPS.

Specification of Letters Iatent.

Patented lice. l9, rare.

Application filed. December 26, 1914:. Serial No. 879,030.

To all whom it may concern:

Be it known that I, Howann It. SAnonn'r, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Current Connections for Electric Lamps, of which the following is a specification.

My invention relates to current connections such as are used for electric lamps and the like, and it includes both bases or plugs and corresponding sockets or receptacles that are especially suitable for the mounting and electrical connection of such lamps, though also applicable and adaptable to other uses.

The invention is more particularly concerned with the transmission of such relatively heavy currents as are required by high candle power tungsten filament incandescent lamps containing nitrogen or other gas or vapor and operating at very high efficiency. it is important that when such a lamp is inserted in a socket or receptacle each of the connections necessary to complete its circuit should. be made with good contact over ample area, in order that the parts shall not be liable to injurious or dangerous overheating, and also for other reasons; How this and other requirements may be met and various advantages obtained through my invention will appear from the following discussion and from the detailed description of particular enibodiments hereinafter, while its scope will be indicated in my claims.

In accordance with my invention, I secure good contact and current carrying capacity by providing the base or plug device with terminals having coacting screw threaded contact surfaces and providing the socket or receptacle device with terminals having correspondingscrew threaded contact surfaces, sothat each of the connections necessary to complete the circuit is a screw thread connection. lhe terminals of these'connection devices can e constructed and arranged in a great variety. of ways, of which only a few are herein specifically illustrated or referred to.

In the accompanying drawings, Figure 1 is a sectional view illustrating a very simple lamp base and socket construction em bodying my invention. Fig. 2 is a fragmentary view, partly in section, showing a lamp with a diiierent type of base also can 'screw shell terminals 12 and 13 also While accurate workmanship and. the or As shown in Fig. 1, the terminals of the lamp base 1 consist of two electrically separate screw threadedshells :2 and 3 of diflei ent diameters or sizes, arranged coarlally one within the other and mechanically united by a body of insulating material 'For the sake of a large cavity for the end ofa high power lamp, the base 1 is pro vided with an ordinary enlarged and insulated skirt 5. The current leads 6 and I of thejlamp are soldered to the terminals 2 and 3 in very much the usual way.

The socket or receptacle 1.1 which receives the base 1 comprises electrically separate ranged coanially one within the other, the

' former being of such diameter that the large base terminal 2 will screw into it easily but snugly, and the latter being similarly adapt ed to screw into the small base terminal.

The terminals 12 and 13 are secured to an insulating body structure 14 by screws l5 and a bolt 16, this bolt 16 and two of the screws 1.5 serving as parts of their current connections. terial of the body structure 1i forms a casing about the terminals 12 and 13 and also forms a stud 17 for mounting the small ter-- minal 13. Though. the external and nal screw threaded contact surfaces of cl base terminals 2 and 3 which coact in ustablishing electrical connections are oi dii? ferent diameters, they may be oi subs ...itially the same pitch, and the like applies to the corresponding screw threaded con tact surfaces of the socket terminals 12 and 13:

The socket terminals 12 and 13 are so arranged that-When the base i is inserted in intoconcurrent threaded engagement with both of them, first engaging the latter a little in advance of the former, howe er.

nar s rin iness oi the metal will. result in As shown, the insulating niatill contact between the threads of each of the base terminals 2 and 3 and those of the corresponding socket terminals 12 and 13, such contact can be insured by allowing considerable backlash or play in the threads and making those of the terminals 2 and 12 of Very slightly different pitch from those of the terminals 3 and 13, so that the base 1 can be screwed far enough into the socket 11 before jamming occurs.

Referring, now, to Fig. 2, it will be seen that the base 31 here shown differs from the base of Fig. 1 in that its coaxial electrically separate screw shell terminals 32 and 33 are arranged endwise and that the screw threaded contact surfaces of both are external. Preferably the pitch of the screw threads of the large terminal 32 is greater than that of the threads of the small terminal 3.3, for reasons which will appear 7 hereinafter. The terminal 32 may be ofthe same size as the screw shell of the base commercially known as the Mogul, and the terminal 33 of the size of the screw shell of the ordinary medium base, and the insulating material 34 may unite them mechanically to one another and to the enlarged skirt 35 in the manner illustrated in U. S. Patent No. 775,689 to Swan, granted Nov. 22, 1904. As shown, the terminal shell 33 is not made'as a closed cap like the terminal 3 of Fig. 1, but with an open lower end from which the insulation 34 projects enough to insure against the production of a short circuit if an ignorant person should screw the lamp into an ordinary medium screw socket.

Referring to Fig. 3, it will be seen that the socket or receptacle device 41 for the base or plug device 31 has screw shell terminals 42 and 43 which are arranged one within the other with their coacting internal differentially screw threaded contact surfaces coaxial and are movable relatively to one another when engaging the corresponding base terminals 32 and 33. The terminals 42 and 43 are mounted on a body structure 44 of porcelain, bisque, or other insulating material which forms a casing about them, the large terminal 42 being fixedly secured by screws 45, while the small terminal 43 is spring mounted so as to be resiliently yielding in an axial direction. As shown, the termlnal shell 43 is in the form of a cup with an angular hole in its bottom, and it is externally insulated by cap-like shell 46 of fiber, poreelain,'bisque, or other insulating material. For mounting the movable or loose terminal 43 with its insulating covering 46 is employed a stud 47 (see Fig. 4) formed of sheet metal suitably punched, bent, and riveted, etc. The head of this stud 47 lies at the bottom of the terminal 43 and may be soldered or otherwise fastened to it, and its angular an inclosing cup or yoke-like shank 48 extends through angular holes in the parts 43 and 46 and through a similar hole at the bottom of a circular recess in the bottom portion of the body structure 44. A heavy helical compression spring 49 in this recess around the shank 48 urges the terminal 43 with its associated parts outtends, while its inward movement is limited by the body structure 44 itself.

Referring to Figs. 3, 5, and 6, it will be seen that the insulating body structure 44 is. provided with a pair of lugs or feet 51 pierced to receive screws for securing the socket in position, and also with lugs 52 that carry binding posts 53, 54, for the connection of the current supply wires. From the binding post 53 electrical connection to the terminal 42 is through two screws 55, a metal piece 56 in. a recessat the bottom of the body structure 44, and two of the screws 45; from the binding post 54 it is through two screws 57, a metal piece 58 with which they engage, and a flexible laminated lead 59 composed of a number of thin copper strips soldered to said piece 58 and clamped to the shank 48 by the piece 50.

It will be seen that the movable or floating terminal 43 with its associated parts is restrained or prevented from turning rela tively to the terminal 42 and its associated body structure 44 by the engagement of the shank 48 with the said body structure, and that axial movement or displacement of said terminal 43 from the position shown (which is its normal one) is yieldingly resisted by the spring means '49. When the base 31 is inserted in the socket 41 and turned clockwise, it comes into concurrent threaded engagement with both of the socket terminals 42 and 43; but the socket parts are preferably so proportioned and arranged that meshing and engagement occur between the terminals 32 and 42 sooner than between the terminals 33 and 43, because with this action any failure of the terminals 33 and 43 to mesh when they first come in contact (owing to defective workmanship or error in assembling the parts) will not cause a jamming, but merely result in the loose or floating terminal 43 being forced inward rather rapidly by further turning of the base until the terminal 33 does mesh and engage with it properly. Once the terminals 32 and 42 and 33 and 43 are in threaded engagement further turning of the base 31 will force the loose terminal 43 slowly inward at a rate depending on how much less its pitch is than that ofthe terminal 42, and the resulting progressive compression of the spring 49 will terminals will insure good contact pressure over a good area. The spring 49 can, however, be dispensed with or made too weak to produce such pressure and good result obtained if the base 31 is simply screwed into the socket 41 until the fioatingsocket terminal 43 is firmly jammed or wedged at the inner limit of its movement, the parts being, of course, so designed that such jamming will occur before the base'terminal 33 bottoms in the socket terminal 43. practicable to block .or entirely do away with movement of the socket terminal 43 if the difi'erence of'pitch between the terminals 32 and 42 on the one hand and the terminals 33 and 43 on the other is made small and the backlash or play between base and socket 33 will not mesh and engage with the movable socket terminal 43 when it first encounters it, but. only after it has forced it inward a certain distance against the resistance of a fairly stiff, strong spring 49.

WVhile I have, in accordance-with require-v ments of the patent statutes, shown and described the best form of embodiment of the invention known to me, I do not'desire to restrict'myself thereto; moreover, I hereby wish to disclaim inventorship of the rela- It is also tively movable or floating terminal and the differential threading of terminals, the same being the inventions respectively of Frederick H. Weston and John A. Orange.

What I claim as new and desire to secure by Letters Patent of the United. States is 1. A high current lamp connection comprising a socket or receptacle device having electrically separate terminals with coacting screw threaded contact surfaces of different diameters and a base or plug device for said socket having terminals with corresponding screw threaded. contact surfaces.

2. A high current lamp connection device comprising electrically. separate terminals with coacting screw threaded contact surfaces of different diameters for concurrent threaded engagement with threaded terminals of a corresponding connection device.

3. A high current socket or receptacle comprising electrically separate terminals with coaxial coacting screw threaded contact surfaces of different diameters for concurrent threaded engagement with threaded terminals of a corresponding base.

4. A high current base comprising electrically separate terminals with coaxial coacting external screw threaded contact surfaces of different diameters for concurrent threaded engagement with terminals of a corresponding socket.

5. A high current base comprising in one unitary structure terminals for'the lamp circuit having coacting screw threaded contact surfaces and a body of insulating material serving to unite said terminals mechanically while separating them electrically said base having a cavity for the end of the lamp.

In witness whereof, I have hereunto set my hand this 24th day of December, 1914.

HOWARD R. SARGENT.

'lVitnesses:

BENJAMIN B. HULL, IIELEN Onrono.

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