An Improved Holder for Electric Incandescent Lamps.
Year: 1891

page_text: Date of Application, 3rd June, 1891
Complete Specification Left, 22nd Feb., 1892-Accepted. 26th Mar. 1892
PROVISIONAL SPECIFICATION.
An Improved Holder for Electric Incandescent Lamps.
I, HUBERT HENRY GRENFELL, of 7 Great Saint Helens in the City of London,
Captain, R.N. do hereby declare the nature of this invention to be as follows:-
My invention relates to holders for incandescent electric lamps.
According to this invention the lamp is cemented or otherwise firmly secured in
a holder of vulcanite or of other suitable insulating material a pair of metallic
contacts being provided at the base of the holder from which contacts conducting
wires for current are led to the lamp. It is preferred that one of the aforesaid
contacts should lie in the axial line of the lamp and the holder, the conducting wire
therefrom being led through the bottom of the lamp bulb, at the centre. The other
contact is of annular form, and the conducting wire therefrom is preferably led in a
direct line to the end of the lamp filament, and passes into the lamp bulb at one
side thereof. The first named or central contact is formed as a screw or plug and
constitutes also a mechanical connection whereby the lamp holder may be secured
to a wire holder or terminal also of insulating material carrying a pair of separate
metallic contacts to which the leads from the generator are connected. One of the
said leads terminates in one of these contacts which is a metallic socket adapted to
engage securely and to make a good electrical connection with the screw or plug
above referred to, and the other lead terminates in the other contact which is a
metallic ring carried by the wire-holder, which ring when the socket in the wire
holder and the screw or plug of the lamp holder are brought together makes contact
with the aforesaid ring on the lamp holder. By these arrangements the lamp
holder may be connected with or disconnected from the wire holder with great
facility and a good electrical connection is obtained.
Dated this 3rd day of June 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for, the Applicant.
COMPLETE SPECIFICATION.
An Improved Holder for Electric Incandescent Lamps.
I, HUBERT HENRY GRENFELL, of 7 Great Saint Helens, in the City of
London, Captain Royal Navy, 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:-
My invention relates to an improved holder for electric incandescent lamps.
According to this invention I construct a holder in two parts formed of vulcanite
or other suitable material. One part is a socket or cup in which the electric lamp
is cemented or otherwise firmly secured. The other part forms a base or support
for the said socket. The two parts are provided with metallic surfaces which
afford a large area of contact in combination with a screw coupling device which
makes a strong and reliable connection of the lamp-socket with the base and
permits the two parts to be very readily connected and disconnected.
The conducting wires from the source of electricity pass through the base or
support to the contact-pieces from which suitable conductors extend to the lamp.
The chief object of my said invention is to provide efficient, simple, and durable
means whereby in the sighting of guns at night an incandescent electric lam) may
be very readily and securely connected to a source of current and may be radily
removed therefrom when necessary.

page_text: In order that my said invention may be readily understood, I will now proceed
to describe the same with reference to the accompanying drawing which shows in
central longitudinal section a lamp-holder with the lamp in place therein and
arranged in combination with the foresight of a gun for illuminating the same.
A and B are the aforesaid two parts forming the socket and base of my improved
holder. They are formed of vulcanite or of other suitable insulating material and
are preferably strengtheued by brass ferrules or hoops ab as shewn. The incan-
descent lamp C is firmly secured in the cavity or recess A' by cement or otherwise.
The base or support B has a head or flange B' whereby it is secured by a screw-
cap, as shown, in the tube or socket of the fore-sight. The said base or support
also serves as a wire holder. The wires or leads D E extend from a generator to
the metallic contacts D' E' carried by the said base B.
The contact D' is an annular piece or ring: the contact E' is a metal piece
screwed centrally into the cbonite and having in it a central screw-threaded hole
for a purpose hereinafter explained.
Fare metallic contacts provided in the part A of the lamp holder. The
contact F is an annular piece or ring firmly secured to the part A and is in
permanent electrical connection by means of the conductor F2 with one of the
terminals of the lamp as shown, that is to say, the wire or conductor Fª is led
directly from the contact through the side of the lamp, to the filament. The
contact F is a screw stem or spindle which is in connection, by means of the
conductor F³, with the other terminal of the lamp.
The said screw stem or spindle F¹ lies in the axial line of the lamp and the
holder, the conductor F3 being led from a platinum disc at the end of the said
spindle through the bottom of the lamp-bulb, at the centre, to the filament. The
contact E in the base B of the holder is, as above specified formed with a central
hole which is screw-threaded to receive the stem or spindle F. The said stem or
spindle must be firmly secured in the socket A by means of a pin or key c or by
cement or otherwise so that it cannot turn in the said socket while being screwed
into and out of the base. It will be seen that the contact-piece E' forms the nut
or female part of a screw-coupling for connecting the parts A and B of the holder.
When the stem F is screwed into the nut E' so that the parts A and B occupy
the relative positions shown in the drawing a good electrical connection is ensured
by the central and annular contact surfaces. Moreover the said screw and nut
form an efficient mechanical connection of the parts A, B, and serve to firmly unite
them while permitting their ready disconnection.
By simply turning the socket A in the proper direction the screw-stem is with-
drawn from the nut and the socket A with the lamp C is released from the
base B.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
First. The socket or cup, having the lamp fixed therein and electrically con-
nected with an annular contact-piece and with a central contact piece which forms
part of a screw coupling for connecting the two parts of the holder substantially as
set forth and for the purpose specified.
Second. The lamp-holder consisting of the two parts A, B, each provided with
a contact-ring and with a central contact piece forming part of a screw-coupling
whereby the two parts are held securely in electrical and mechanical connection
substantially as and for the purpose specified....
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.