Improvements in Insulators for Incandescence Electric Lamps.
Year: 1898

page_text: Communicated from abroad by ALBERT HALLER SPENCER, of 53, State Street,
Boston, Massachusetts, United States of America, Solicitor of Patents.
Improvements in Insulators for Incandescence Electric Lamps.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:
My invention relates to improvements in insulating fittings for incandescent
electric lamps.
The object of this invention is to provide for ordinary incandescent electric
lamps of the so-called Edison type, an improved insulating sleeve, which
shall obviate the dangers incident to the exposure of the outer portion of the
metallic shell or collar (into which the neck of the bulb is set) to contact with
external conducting substances. The base of this shell or collar is screw-
threaded to engage with the sheet-metal screw socket of the lamp, both of said
parts being in the electrical circuit, and hence requiring to be kept free from
danger of contact with other conductors.
In these lamps as heretofore introduced, and now largely used, it is customary
to surround the neck of the bulb and the collar thereon with a short hard-rubber
ring, internally threaded to screw upon the outside of the sheet metal screw-
socket, and thus to insulate the conductors from the metallic bracket or wall
fixture, such ring having around its outer margin a radial flange or enlarge-
ment which bears against the adjacent surface of the porcelain reflector sur-
rounding the lampneck, or against the outer sleeve of the bracket, so as to hold
such reflector or sleeve in position when the bulb is removed and replaced.
Said ring, however, does not cover the outer portion of the shell or collar fixed
on the neck of the bulb, and hence such collar is exposed to accidental metallic
contacts involving fire risks and other dangers.
My improved insulating sleeve accomplishes perfectly both these objects, and
complies with recent requirements of the National Board of Fire Underwriters
as to such exposures. My invention is embodied in a hard-rubber or other non-
conducting tube internally screw-threaded to engage with the threaded socket,
and having, about midway of its length a thickened and preferably milled
annular portion or shoulder extending outwardly from its periphery to bear
against the reflector or the bracket sleeve, the tubular body extending above
and below said shoulder or annular portion. By preference I make these pro-
jecting end-portions about equally thin, so that either end will pass through
the central opening in the reflector and enter between the bracket sleeve and
the threaded socket, making the device reversible. I provide also a supplemen-
tary washer slipped over the reduced end of the insulator, between the shoulder
and the reflector, when desired.
In carrying my invention into practice the neck of the lamp-bulb is provided

page_text: with the permanently affixed collar having a spiral corrugation or coarse screw
thread extending about two thirds of its length. The usual sheet metal screw-
socket into which the threaded end of the shell or collar is screwed is also
provided.
My improved insulator is internally threaded to screw upon the exterior of
the threaded socket and formed midway of its length with the raised external
shoulder or ring serving to hold the reflector in place and as a stop to prevent
screwing the insulator in too far. The outer end of the device extends beyond
and effectually covers and insulates the metallic collar, thus preventing contact
of any electrical conductors therewith. The end portions being much thinner
than the raised external ring either end may screw in between the socket and
the surrounding portion of the metal bracket, while the other extends over the
outer end of the collar and around the lamp neck. The outer end of the insu-
lator may be as thick as the external ring, but material is saved and the
appearance improved by reducing the ends.
The relative dimensions of these end portions may vary so long as one of
them covers the outer part of the collar while the other insulates the lamp from
the bracket. In some
cases I provide a suitable washer surrounding the
reduced end of the insulator between the external ring and the face of the
reflector. This washer I use when the reflector is omitted or in cases where
the metal shell or collar of the lamp is of unusual length, my insulator being
thus held somewhat further out on the neck of the lamp.
Dated this 8th day of November 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
Improvements in sulators for incandescence Electric Lamps.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
"
The object of this invention is to provide for ordinary incandescent electric
lamps of the so-called " Edison type, an improved insulating sleeve, which
shall obviate the dangers incident to the exposure of the outer portion of the
metallic shell or collar (into which the neck of the bulb is set) to contact with
external conducting substances. The base of this shell or collar is screw-
threaded to engage with the sheet-metal screw-socket of the lamp, both of said
parts being in the electrical circuit, and hence requiring to be kept free from
danger of contact with other conductors.
In these lamps as heretofore introduced and now largely used it is customary
to surround the neck of the bulb and the collar thereon with a short hard-rubber
ring internally threaded to screw upon the outside of the sheet-metal screw-
socket, and thus to insulate the conductors from the metallic bracket or wall-
fixture, such ring having around its outer margin a radial flange or enlarge-
ment which bears against the adjacent surface of the porcelain reflector sur-
rounding the lamp-neck, or against the outer sleeve of the bracket, so as to hold
such reflector or sleeve in position when the bulb is removed and replaced.
Said ring, however, does not cover the outer portion of the shell or collar fixed
on the neck of the bulb, and hence such collar is exposed to accidental metallic

page_text: contacts, involving fire risks and other dangers. My improved insulating-sleeve
accomplishes perfectly both these objects.
My invention is embodied in a hard-rubber or other non-conducting tube
internally screw-threaded to engage with the threaded socket and having about
midway of its length a thickened and preferably milled annular portion or
shoulder extending outwardly from its periphery to bear against the reflector
or the bracket-sleeve, the tubular body extending above and below said shoulder
or annular portion. By preference I make these projecting end portions about
equally thin, so that either end will pass through the central opening in the
reflector and enter between the bracket-sleeve and the threaded socket, making
the device reversible. I provide also a supplementary washer slipped over the
reduced end of the insulator, between the shoulder and the reflector, when
desired.
In the accompanying drawing,
Figure 1 represents a lamp provided with one of my improved insulators,
shown in longitudinal section.
Figures 2 and 3 represent the insulator in perspective and in longitudinal
section, and
Figure 4 shows it provided with a supplementary ring.
Figure 5 is a modified form in which the enlargement extends to the outer
end, and
Figure 6 shows the supplementary ring detached.
A represents the neck of the lamp-bulb, provided with the permanently-
affixed collar B, having a spiral corrugation or coarse screw-thread extending
about two-thirds of its length.
C is the usual sheet-metal screw-socket into which the threaded end of the
shell or collar B is screwed.
D is my improved insulator, internally threaded to screw upon the exterior
of the threaded socket C and formed midway of its length with the raised
external shoulder or ring D¹, serving to hold the reflector E in place and as a
stop to prevent screwing the insulator in too far. The outer end of the device
extends beyond and effectually covers and insulates the metallic collar B, thus
preventing contact of any electrical conductors therewith. The end portions
being much thinner than the ring D¹, either end may screw in between the
socket C and the surrounding portion F of the metal bracket, while the other
extends over the outer end of the collar B and round the lamp-neck. The
outer end of the insulator may be as thick as the ring D', as shown in Figure 5;
but material is saved and the appearance improved by making it as shown in the
other figures. The relative dimensions of these end portions may vary so long
as one of them covers the outer part of the collar B, while the other insulates
the lamp from the bracket. In some cases I provide a suitable washer G, sur-
rounding the reduced end of the insulator between the ring D₁ and the face of
the reflector. This washer I use when the reflector is omitted or in cases where
the metal shell or collar B of the lamp is of unusual length, my insulator being
thus held somewhat farther out on the neck of the lamp.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what I claim is:-
1. The described reversible insulator formed of non-conducting material inter-
ually threaded, having about centrally a thickened peripheral ring and at
either side thereof thinner end portions projecting longitudinally from and of
less diameter than said ring, substantially as set forth.
2. The lamp A with fixed collar B and wall-socket C in the electric circuit,
in combination with the tubular insulator D D¹ of such length as to cover the
outer portion of the collar and extend between said collar and the bracket-

page_text: sleeve F, and with the supplementary washer G adjacent to the shoulder D¹,
substantially as set forth.
3. The incandescent lamp A with its threaded shell or collar B, the sheet-
metal screw-socket C and the bracket-sleeve F, in combination with the
threaded non-conducting tube 1 formed with the radial shoulder D1 adapted
to support the reflector E, and with the projecting ends respectively insulating
said sleeve from the socket and the outer end of said collar from external con-
ductors, substantially as set forth.
T
17
1900
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.