Improvements in Lamp Holders.
Year: 1894

page_text: Date of Application, 1st Nov., 1894
Complete Specification Left. 31st July, 1895-Accepted, 26th Oct., 1895
Improvements in Lamp Holders.
I, HENRY LEA, of Bennetts Hill, in the City of Birmingham, Civil Engineer,
lo hereby declare the nature of this invention to be as follows:-
My invention relates to lamp holders for incandescent electric lamps and it
consists in so arranging the parts of a lamp holder that while an elastic pressure is
provided for its contact pieces there are no springs which either conduct the
current to the lamp, or which surround or impart individual elasticity to the contact
pieces whereby the risk of such springs becoming softened by heat and thereby
rendered inoperative is entirely avoided.
1 will describe one way in which I carry out my invention-In my description
the holder is supposed to be above the lamp, although in actual use it may be
placed below it or the axis of the holder and of the lamp may occupy any angle,
according to the taste of the user as is well understood.
I take a piece of metallic tube of such a size as will fit over the socket or
collar of the lamp, and I fix a cap upon the top of the tube screwed to receive
either a suspension tube or a cord grip as is well understood. The lower portion
of the tube has slots to form the bayonet joint attachment for the lamp in the usual
manner.
I provide a coiled spring which fits easily within the tube. The top of the
The bottom of the spring rests upon
spring abuts against the cap of the tube.
and presses downwards a transverse pin passing through two slots in the sides of
the tube. Thus the transverse pin can be raised a short distance against the
pressure of the spring but cannot be forced by the spring any lower than the
bottom of the slots.
Within the spring 1 place an inner short piece of tube pierced transversely with
two holes to receive the transverse pin upon which it can rock as on a horizontal
axis within such limits as its freedom within the coiled spring will allow. The
inner tube has a small internal flange at its lower end which flange is embraced
between two discs of non-conducting material which are fastened together by two
screws so as to pinch the flange and hold the discs securely in position. The same
screws secure two flat semi-circular pieces of metal to the lower face of the lower
disc. Each semi-circular piece has two portions of it projecting downwards a
short distance, one of which is drilled to receive the end of the flexible conductor
and to receive a screw for securing the conductor in position while the other
projection is solid and preferably rounded off at its lower end to bear against the
contact piece of the lamp. A line drawn through the two solid projections lies at
right angles to the axis of the aforesaid transverse pin. The two solid projections
constitute the contact pieces of the bolder.
When the lamp is introduced into the holder the flat contact pieces of the lamp
These being free to rock
bear against and raise the contact pieces of the holder.
upon the transverse pin accommodate themselves to the contact pieces of the lamp
and thus make an even contact on both, and being pressed downwards by the spring
Between the
bear upon the contact pieces of the lamp with an elastic pressure.
ends of the flexible conductors and the contact pieces of the lamp there are thus
none but solid pieces of metal having no springs whatever in metallic contact with
them, while the only spring which I employ is situated well up in the lamp holder
and in the cooler part thereof.

page_text: I may vary the details of this arrangement provided that I obtain always a
rocking contact piece within the holder held down by a spring thereby an even
contact pressure is obtained upon the two terminals of the lamp without the
necessity for applying to the contact pieces of the holder any springs for giving
individual elasticity to them.
Dated this 21st day of October 1801
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.
www
I, HENRY LEA of Bennetts Hill in the City of Birmingham, Civil Engineer,
do hereby declare the nature of my sáid 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 lamp holders for incandescent electric lamps, and,
consists in so arranging the parts of a lamp-holder that while an elastic pressure is
provided for its contact pieces there are no springs which either conduct the
current to the lamp, or which surround or impart individual elasticity to the contact
pieces whereby the risk of such springs becoming softened by heat, and thereby
rendered inoperative is entirely avoided.
The aim and object of my invention being to obtain a rocking contact piece
within the holder held down by a spring, whereby an even contact pressure is
obtained upon the two terminals of the lamp without the necessity for applying to
the contact pieces of the holder any springs for giving individual elasticity to
them.
In order that my invention may be more clearly understood, I will now proceed
to describe it with the aid of the accompanying two sheets of drawings Figs. I to X
both inclusive. The same letters indicate the same parts in all the figures.
Fig. I is a vertical section through a lamp holder constructed according to my
invention, and by my first method.
Fig. II is another vertical section through the same, taken on a plane at right
angles to that on which Fig. I is taken.
Fig. III is a plan of the underside of the lamp holder as shown in Figs. I
and II.
Fig. IV is a vertical section of a lampholder constructed according to my second
method.
Fig. V is a vertical section through the same taken on a plane at right angles to
that on which Fig. IV is taken.
Fig. VI is a plan of the underside of the lamp holder as shown in Figs. IV
and V.
Fig. VII is a cross section of Fig. V taken at uu.
Fig. VIII is a vertical section of a lamp holder showing the modification of the
contact pieces.
Fig. IX is a vertical section of the same taken on a plane at right angles with
that on which Fig. VIII is taken.
Fig. X is a plan of the underside of the lamp holder showing the modified
contact pieces.
a is the
Figs. I II and III illustrate one method of carrying out my invention.
outer metallic tube of the lamp holder. It is shouldered down at b and has a screw
cap c.
It also has two opposite slots d to form the bayonet joint attachment for

page_text: 9. 9. which
the lamp. e is a coiled spring which fits easily within the tube a. The top of the
spring e abuts against the cap c. The bottom of the spring e rests upon and
presses the transverse pin f downwards upon the bottom of the two slots
pierce the opposite sides of the tube a. is a short piece of tube fitting loosely
within the coiled spring e so as to rock within moderate limits upon the pin f which
passes transversely through the tube h. i is an internal flange at the lower end of
the tube h, and k. l. are two discs of a rigid material being a non-conductor of
electricity, which are held together by two screws m so as to embrace the flange i
between them. The same screws secure also the two contact-pieces n, n. Each of
which consists of a curved plate o with a socket p which receives the end of the
conducting wire, and has a side screw 9 for securing the wire in position. Each
plate n also has a contact peg r which bears against one of the two contact pieces
of the electric lamp. When the electric lamp is placed in the holder, the contact
pieces of the lamp abut against and raise the contact pegs r, the discs k. l, the tube h
and the transverse pin fagainst the pressure of the spring e. These parts being
free to rock upon the pin the contact pegs r accommodate themselves to the
contact pieces of the lamp and make even contact with both of them.
Figs. IV, V, VI and VII illustrate another method of carrying out my
invention. In this method the spring e presses downwards the solid disc k upon an
internal shoulder s. The disc is made of a rigid material which is a non-
conductor of electricity and is somewhat cylindrical in shape, but slightly rounde.l
off as shown at t so as to allow it to rock within the tube a. To the disc k are
secured the contact pieces n, o, p, q, as already described. In order to prevent
the disc from rotating within the tube a, I form at opposite sides of the tube a,
two inner projections u, which enter two corresponding notches cut in the sides of
the disc k. The action of this form of holder when the lamp is introduced is
similar to that of the form illustrated in Figures I II. and III, although the details
are somewhat different that is to say, in both forms of my invention the flat contact
plates of the lamp raise the contacts r of the disc k, together with the disc itself
against the pressure of the spring e. By the rocking of the disc k even contact is
secured between the pegs r and the contact plates of the lamp.
Figs. VIII, IX and X illustrate a modification in the contact pieces of my
lampholder which modification is applicable to either of the forms of holder already
described. Each contact piece consists of a screwed part v, a nut w, a collar a,
a side screw y and a longitudinal central hole z. Each nut w is sunk into the disc k
and is screwed down by means of a notched screw driver, so as to hold the contact
piece securely to the disc. The ends of the contact picces are rounded off so as to
bear upon the contact pieces of the electric lamp. By this method of construction
I simplify the contact pieces which now have no base plates but are by preference
cylindrical throughout the same piece of metal both receiving the conducting wire
and bearing upon the contact plate of the electric lamp.
I have described and illustrated the methods best known to me by which my
invention may be carried into effect, but I do not confine myself to the precise
methods as these may be varied in detail without departing from the nature of my
invertion.
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 :-
:-
1. In a lampholder for an incandescent electric lamp the combination of a main
spring, with a rocking disc or discs, and contact pieces devoid of individual or local
springs as and for the purpose hereinbefore described and shown upon the
accompanying drawings.
2. In a lampholder for an incandescent electric lamp the combination of a main
spring, a rocking disc or discs and simplified contact pieces as described and
illustrated in Figures VIII IX and X on the accompanying drawings as and for
the purposes set forth.

page_text: 3. In a lampholder for an incandescent electric lamp, the general construction
combination and arrangement of parts substantially as and for the purposes
herein before described in the foregoing Specification and illustrated upon the
accompanying sheets of drawings.
01.1ניב
T.1 1005
THOS. KENDRICK,
3 Cherry Street, Birmingham, Agent.