(No Model.)
`
`No. 438,310.
`
`T. A. EDISON.
`LAMP BASE.
`‘ Patented 001;. 14, 1890.
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`Page 1
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`POLYGROUP EX. 1038
`POLYGROUP V. WILLIS
`
`

`
`UNITED STATES ATENT OFFICE.
`
`THOMAS A. EDISON, OF ORANGE, NEIV JERSEY.
`
`LAM P-BASE. '
`
`SPECIFICATION forming part of Letters Patent No. 438,310, dated October 14, 1890.
`Application filed May 5, 1890. Serial No. 350.611- (No model.)
`I
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`10
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`To all whom it may concern:
`Be it known that I, THOMAS A. EDISON, of
`Orange, in the county of Essex and State of
`New Jersey, a citizen of the United States,
`have invented a new and Improved Lamp
`Base, (Case No. 856,) of which the following
`is a speci?cation.
`My object is to adapt my incandescent
`electric lamps for use not only with the socket
`ordinarily employed in my systems of elec
`tric lighting, but also with sockets employed
`in other electric-lighting systems. This in
`. terchangeable feature is frequently of great
`value-for example, when a building has
`been wired and. equipped by one lighting
`company and for some reason it is desired to
`substitute my lamps. In this case with the
`interchangeable terminals the ordinary sock
`ets may be left in place and used in connec
`tion with the substituted lamps.
`My invention consists in the construction
`and arrangement of devices for accomplish
`ing the above-named object, hereinafter de
`scribed and claimed.
`In the accompanying drawings, which illus—
`trate my invention, Figure 1 is a side view of
`one of my incandescent lamps with the im
`proved terminal attached. Fig. 2 is a plan
`view of the same with the plug removed.
`Fig. 3 is a central cross-section through the
`base of the lamp. Fig. 4. shows two terminals
`of different forms detached from the lamps.
`Fig. 5 is an insulating-ring, which will be
`hereinafter described. Fig. 6 gives two views,
`a central section and a plan, respectively, of
`an Edison socket of the simplest form. Fig.
`7 shows two similar views of the essential
`features of a W'estinghouse socket, and Fig.
`8 two similar views of the essential features
`of a Thomson-Houston socket.
`In my lamp, as is well known, the base
`consists of a metal sleeve or ring 1, connected
`to one end of the incandescing ?lament, and
`a central terminal insulated from the sleeve‘ '
`and connected to the other end of the ?la
`ment. At the outer end the sleeve is bent
`over, as indicated at 1’. In the present in
`vention the second terminal consists of a
`metal ring or ?lament terminal 2, preferably
`constructed with an internal screw-thread
`and having a ?ange 3. The ringis forced into
`an insulatingewasher 4, and said washer and
`
`40
`
`ring are supported and held in place in the
`completed lamp by plaster-of-paris or other
`suitable material, as indicated at 5. In the
`55
`outer periphery of the washer are made one
`or more notches ll’. When the plaster-of
`paris is placed as shown, it enters these
`notches and prevents the washer from turn
`ing. 6 and 6’ indicate two plugs or extension
`terminals adapted to ?t into the central ring
`2. The form of plug indicated at 6 is shown
`inserted in the ring in Fig. 1. This adapts
`the lamp for use with the ordinary Edison
`
`socket.
`
`,
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`65
`
`Referring to Fig. 6, it will be seen that'if
`the base of the lamp be screwed into the
`socket the sleeve 1 would form electrical con
`tact with the socket-sleeve 7, connected to one
`wire of the circuit, while the plug or termi
`nal 6 would make end contact with the screw
`8, connected to the other wire of the circuit.
`Suppose now it were desired to use the lamp
`illustrated in Fig. 1 in a building which had
`been wired and equipped with the Westing
`house system. The sockets would be of sub
`stantially the construction shown in Fig. 7,
`one terminal of the circuit being connected
`to the central spring-arms 9 and the other
`terminal of the circuit to the spring-arms 10.
`The terminal 6 should be removed and the
`terminal 6’ put in its place. Then the lamp
`could be pushed directly into the socket in
`stead of being screwed in, as in the case of
`the socket illustrated in Fig. 6, the central
`pin or terminal passing between the spring
`arms 9, and the curved ends of the springs
`10 snapping over the bead 11 on the lamp
`base, thus completing the circuit-connection
`through the lamp.
`_
`Suppose now it were desired to use the lamp
`in connection with the Thomson-Houston
`socket, such as illustrated in Fig. 8. The
`socket would be provided with aring terminal
`12, connected to one wire of the circuit, and
`95
`a central screw=threaded terminal 13, con
`nected to the other wire of the circuit, and
`the shell 14 would be of suf?cient size to 'al—
`low the base of the lamp to be easilyinserted.
`In this case it would be necessary to remove
`the central plug from the ring 2 ofthe lamp.
`When the lamp is then put in place, the over
`turned ?ange 1’ rests on the ring terminal 12
`and the ring 2 screws onto the terminal 13,
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`too
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`438,310
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`thus completing the circuit. When the lamp
`is used with this form of socket, it is found
`desirable to place an insulating-ring around
`the neck of the lamp—for example, just above
`the bead 11, as indicated at 15. This insu
`lating-ring is preferably broken at one point,
`as indicated. in Fig. 5, so that it can be read
`ily sprung over the bead on the lamp-base.
`This insulating-ring serves to prevent elec
`trical contact between the sleeve of the socket
`and the ring terminal 1 of the lamp, and thus
`prevents danger of a short circuit, which
`would occur if the shank of the switch-han
`dle on the socket should electrically connect
`the sleeve of the socket when it was in con
`tact with ring 1 with the circuit-wire, which
`is connected to the central terminal of the
`lamp. ,
`-
`
`10
`
`By the simple device described, consisting
`of a screw-threaded terminal 2 and the two
`plugs of slightly differing shape, I am thus
`enabled at a tri?ing expense to construct
`lamps which may be used at will with either
`of the three leading forms of electric-lamp
`sockets, and it is evident that this is a very
`useful and desirable feature.
`I am aware that lamps which are adapted
`to be used with two sockets of different make
`by means of an intermediate connect-ing
`sleeve have been proposed heretofore.
`Having thus described my invention, what
`' I claim is
`1. An incandescent-electric-lamp base hav
`-ing, in combination, an externally- screw
`threaded sleeve permanen tly connected to one
`35
`end of an incandescing ?lament and an inner
`terminal with a central bore insulated from
`the ?rst and connected to the other end of the
`?lament, substantially as described.
`2. An incandescent-electric-lamp base hav
`in g, in combination, an externally- screw
`threaded sleeve permanently connected to one
`end of an incandescing ?lament, an inner ter
`minal with a central bore insulated from the
`?rst and connected to the other end of the
`?lament, and a removable plug or extension
`terminal in said central terminal, substan
`tially as described.
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`20
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`25
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`45
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`55
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`6.5
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`3. The combination, with a socket consist
`in g of a sleeve with internal screw-thread
`connected to one wire of a circuit‘ and in the
`base of said socket a terminal connected to
`the other wire of the same circuit, of a lamp
`the base of which is provided with an exter
`nally-screw-threaded sleeve connected to one
`end of the ?lament, a terminal with a central
`bore permanently connected to the other end
`of the ?lament, and a removable plug therein
`co-operating with said socket-terminal, sub
`stantially as described.
`.
`4- An incandescent-lamp base forming an
`integral part of the lamp adapted for use in
`different sockets, consisting of a circumfer
`ential terminal co-operative with the corre
`sponding terminal in the socket, a centrally
`bored terminal, and a removable plug for said
`bore corresponding to the shape of the- sec
`ond socket terminal and co-operative‘ there-
`with, substantially as described.
`5. An incandescent-lamp base consisting of
`a ring terminal co-operative with a corre—
`sponding terminal‘ in a socket, an insulator
`around the ring terminal, a centrally-bored
`terminal, and a removable plug for said bore
`corresponding to the shape of the second
`socket terminal and co-operative therewith,
`substantially as described.
`6. The combination, in an incandescent
`lamp base, of a ring terminal 1, permanently
`connected to one end of the _?lament,insulat
`ing-washer 4, and ring terminal 2, held there~
`in and permanently connected to the other
`end of the ?lament, substantially as described.
`' 7. In an incandescent-lamp base, the com-~
`bination of the ring terminal 1, connected to
`one end of the ?lament, insulating-washer 4,
`provided with notches, the ring terminal being
`connected to the other end of' the ?lament,
`and the binding material 5, substantially as
`described.
`‘
`
`This speci?cation signed and witnessed this
`25th day of April, 1890.
`'
`THOS. A. EDISON.
`.
`
`‘Witnesses:
`HARRY F. MILLER,
`A. RAE.
`
`Page 3