IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS
Year: 1886

page_text: I FREDERIC SCHAEFER of the City of Boston in the State of Massachusetts,
United States of America, Electrician, do hereby declare the nature of my Inven-
tion for "IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS" and in what manner
the same is to be performed, to be particularly described and ascertained in
and by the following statement :—
This invention relates to incandescent electric lamps, and has for one of its
objects to improve the construction of the lamp-holder whereby a sure and reliable
contact is made between the terminal electrodes of the carbon filament and the
contact pieces secured to the insulating block or disk, and whereby the lamp is
prevented from being short circuited.
My invention also has for its object to provide the lamp-holder with a switch,
which shall be simple in construction yet sure and reliable in operation.
My invention still further has for its object to simplify the construction of the
lamp-holder so that a deranged lamp may be quickly replaced without necessitating
the removal of the holder from its fixture or support. Another feature of my
invention consists of a shade secured upon the lamp without necessitating the use
of additional means to keep it in place upon the lamp.
My invention consists essentially of a holder composed of a sleeve or case
provided at one end with a socket, preferably screw-threaded, and by which the
holder may be secured in any desired position, the socket being engaged with or
screwed upon a proper projection, an insulating block or disk provided with a slot,
and having contact pieces upon its upper and lower faces, said contact pieces on
the upper face of said block or disk being provided with out-turned flanges by
which to stop rotation of the lamp within its holder, a spring to act upon said
insulating block or disk to normally force the contact pieces upon said upper face
against the terminal electrodes of the carbon filament, herein shown as lugs pro-
jecting from the plaster-of-paris mold which encloses the neck of the lamp, said
mold being itself encircled by a band provided with projections co-operating with
slots and a groove in the sleeve or case, said projections, slots and groove acting
like a bayonet joint between the lamp and holder.
My invention consists also in combination with the slotted insulating block or
disk, having contact pieces above and below said slot, of a key having a collar
composed of metal and insulating material inserted in said slot, and co-operating
with said contact pieces, whereby the circuit of the lamp is completed when the
metal portion of said collar is in contact with the contact pieces above and below
said slot, and whereby said circuit is broken when said metal portion is not in
contact with said contact pieces.

page_text: "
My invention still further consists in a bulb, a mold to nord Bald DuTD, & Dan
surrounding said mold and provided at one end with a flange to form a seat for
a shade, and having pins or projections at or near its other end, combined with a
shade having a collar provided with grooves whereby said shade may be fitted to
its seat on said flange, and with a holder having a groove in which said pins are
rotated to fasten the lamp to said holder, and to secure the shade firmly upon
the lamp.
"
My invention further consists in details of construction to be hereinafter pointed
out in the claims at the end of this specification.
Fig. 1 is a vertical section of a complete incandescent electric lamp embodying
my invention.
Fig. 2 a section of Fig. 1 on line xx with the shade removed.
Fig. 3 a side elevation of the insulating block or disk partially broken out, the
key being removed.
Fig. 4 a view of Fig. 3 looking upward.
Fig. 5 a top view of the shade removed from the lamp and broken off.
Fig. 6 a perspective view of the key removed from the insulating block or disk,
the handle being omitted.
Figure 7 a detail to be referred to and Fig. 8 a sectional view of a part of the
lamp holder with the lamp removed, the section being at right angles to that in
Fig. 1.
The bulb A, containing the carbon filament a, and platinum electrodes a¹, a² is
imbedded in a plaster of paris mold a³, in which are secured the terminal lugs
a as to which the platinum electrodes are attached, said platinum electrodes
being herein shown as inserted through arms a6 a7, see Fig. 7, of a cross-shaped
piece, preferably of glass located in the bulb A, and near its neck, said cross-
shaped piece being of sufficient size to prevent the carbon filament from being
displaced from its normal position in the center of the bulb by sudden jarring, and
similar causes.
The mold a³ is surrounded by a metal band b provided with pins or projections
61 62, which enter slots 63 b, see Fig. 2, in the sleeve or case B of the lamp-holder,
and are rotated in a groove b³ in said sleeve or case when the lamp
its holder.
secured to
The sleeve or case B, herein shown as struck up from sheet metal and shaped as
shown, is provided at one end with a screw-threaded socket c, by which the holder
may be secured to any suitable or proper support in any desired place.
The sleeve or case B contains within it a spring c¹, and a disk c² of insulating
material, separated from said spring by a washer c³, also of insulating material, said
insulating disk being slotted as at c', see Figs. 3 and 4, to receive a key co.
The insulating disk c² has secured to one of its faces by screws d-d¹, contact
pieces d² d³, each of said contact pieces being provided with an outturned flange d',
said flanges being preferably in the same diametrical line, as shown in Fig. 4, the
contact piece being extended over the slot c¹.
The insulating disc c³ is provided with a central opening, through which con-
ducting wires are led, the wire being connected to the screw and the
wire do to a screw d', which is extended through the insulating disc c², and screwed
into a metallic ring e², see Fig. 3, secured to the opposite face of the disk c², said
metallic ring being upset as at e³.
The spring c¹ normally forces the contact pieces d³ up against the terminal
electrodes a as, thus establishing good electrical connection between the lamp and
holder.
The vertical movement of the insulating disk c² within the sleeve or case is
limited by suitable stops, herein shown as screws c, which are screwed into said
disk, and extending through slots e¹ in said sleeve or case, strike against the ends
of said slots; but it is evident other means may be employed to limit, the said
movement, such as a shoulder projecting from the inside of the sleeve or case, or a
5

page_text: 1
re-encrane portion Of the case itsell above said disk, as shown in dotted lines,
(Fig. 8).
The key is composed of a metal collar f having insulation f¹, see Fig. 6, the
metal part of said collar having a shank f³, on which is secured a handle f³, the
insulation being provided with a groove 2, and the metal with a groove 3.
The collar referred to is designed to enter the slot ct, and to be rotated therein
by turning the handle f³, and the said collar is locked and maintained in position
within said slot by the upset portion e³ of the metallic ring e*, which enters one of
the grooves, 2, 3, according as the lamp is in or out of circuit, and also by means of
washers ff, which are mounted on the shank f2 of said collar, and which act
frictionally to further lock and maintain said collar in position, said washers being
one on the inside, and the other on the outside of the sleeve or case B, as shown
in Fig. 1.
The lamp is attached to its holder by inserting the pins or projections b¹ b³ in
the slots bb, and then rotating said pins in the groove bs, and during such move-
ment the terminal electrodes a a³ act against the contact pieces d d³ and push the
insulating disk back against the action of the spring c¹, which supports it in a
yielding manner, and as the lamp is rotated, the terminal electrodes bear against
or wipe over the contact pieces, thus forming a rubbing contact and securing the
best possible electrical connection.
When it is desired to place the lamp in circuit, the handle f³ is turned so as to
have the metal portion f of the collar engaged by the contact piece d' on one side,
and by the metal ring e' on the other side-the upset portion e³ of said ring
entering the groove 3, and locking the key c³ until positively moved.
With the lamp in circuit, the current enters the lamp by wire to the contact
piece d³, from contact piece d³ through the filament a to contact piece d², from
contact piece to the metallic ring e by the metal portion f of the collar, and from
the metal ring e² to the wire d by screw d.
The manner of completing the circuit in the lamp as just described is especially
advantageous in this class of incandescent electric lamps.
When the lamp proper is connected to its holder, all danger of short circuiting
of said lamp is obviated by means of the out-turned flanges d*, which limit the
rotation of the lamp in its holder.
Referring to Fig. 1 it will be seen that the band b is flanged at its lower end
as at h, said flange forming a seat for the collar h¹ of a shade 2, said collar being
struck up and provided with grooves - see Fig. 5, which perinit the shade to be
shipped over and past the pins or projections 61 62 to its seat on the flange h,
said pins travelling in said grooves when the shade is placed upon the lamp, said
shade being maintained in position upon the lamp by means of the sleeve or case B
of the holder.
To remove the shade from the lamp, the lamp is first removed from its holder,
and the pins or projections b', 6' on the band bare slipped through the
grooves in the collar of the shade.
Inasmuch as the lamp and holder are separate and detachable, it is evident that
the said lamp, if broken or otherwise damaged can be quickly removed and
replaced by another without disturbing the holder, the construction of which is so
simple that it will require very little repairing.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. In an incandescent electric lamp, a sleeve or case having stops to control the
extent of outward movement of an insulating block or disk, and provided with a
socket, combined with the insulating block or disk having contact pieces, and with
a spring supported in the bottoin of the sleeve or case, and acting at one end upon
the under side of and moving said insulating block or disk outward, substantially
as described,

page_text: 2. The lamp provided at its neck with terminal electrodes, and having
projections 61 62, combined with a sleeve or case having a groove 65 slotted at 63-6
to enable said projections to enter the said groove, and having stops and a socket
connected with said sleeve or case, a spring located in said sleeve or case and
supported by it at or near the said socket, and the insulating block or disk
provided with contact pieces, whereby, when the projections on the neck of the
lamp are entered into and made to follow in the groove 66, the terminal electrodes
act against the contact pieces d³ d* and force the insulating block or disk back
into the sleeve or case, compressing said spring, the terminal electrodes rubbing or
sliding over the contact pieces as the lamp is being turned to secure it in place
substantially as described and shown.
3. In an incandescent electric lamp, the sleeve or case, the spring supported in
the bottom of said case, the insulating block or disk c provided with the slot c
and acted upon by said spring, combined with a key provided with a collar,
composed of metal and insulating material substantially as described, and with
contact pieces secured to the said insulating disk to co-operate with said collar,
substantially as specified.
4. The sleeve or case B, the spring c', the insulating block or disk provided with
the slot and acted upon by said spring, combined with a key having a collar
composed of metal and insulating material substantially as described, and provided
with grooves 2, 3, and with the contact pieces d³ d³ and e³, the latter being upset
as at e³ to enter one of said grooves to lock the switch, substantially as set forth
and shown.
5. In an incandescent electric lamp, the bulb A, the mold to hold said bulb, and
terminal lugs at a incased in said inold, combined with the insulating disk c
having contact pieces d² d³ secured thereto, and provided with outwardly turned
flanges to be engaged by said lugs, to thereby prevent said lamp from being
short circuited substantially as described and shown.
6. In an incandescent electric lamp, the insulating disk c² provided on one face
with the metal ring e³, upset as at e³, and having contact pieces d² d³ secured to its
opposite face; combined with the key c, composed of a metal collar f having
insulations f¹, and with the screw d secured to the metal ring e³, and by which
the current is conducted to the line wire, substantially as described and shown.
7. In an incandescent electric lamp, the bulb, the mold to hold said bulb, the
band surrounding said mold, and provided at one end with a flange, and having a
pin or pins at or near its other end, combined with the shade h³ having the collar h
provided with a groove or grooves, whereby said shade may be fitted to its seat on
said flange, and with a holder having a groove in which said pin or pins are
rotated to fasten said lamp to said holder, said holder securing said shade firmly
upon said lamp, substantially as described and shown.
8. In an incandescent electric lamp, the bulb A, the mold to hold the said bulb,
the lugs as a incased in said mold, the platinum electrodes a¹ a² attached to said
lugs, combined with the cross-shaped piece having arms a a7 to which the
electrodes aa² are sealed, and with the carbon filament a secured to said
electrodes, said cross-shaped piece preventing the carbon filament from being
displaced, substantially as described and shown.