Improvements in and relating to Electric Incandescent Gas Lighting.
Year: 1899

page_text: Date of Application, 26th Apr., 1899
Complete Specification Left, 15th Dec., 1899-Accepted, 20th Jan.,
1900
PROVISIONAL SPECIFICATION.
Improvements in and relating to Electric Incandescent Gas Lighting.
I, MAURICE LACHMAN, of 29A. Gillingham Street, Pimlico, London, S.W.,
Engineer, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to produce the caps for electric incandescent
lamps in a simpler and more efficient manner than heretofore.
These caps, into which the bulbs of the lamps are usually secured by plaster
of Paris, are generally formed from thin brass tubing, the external studs or
projections which enter the bayonet notches or slots in the socket, being fixed
to the cap by soldering.
This thin brass tubing, which is used for cheapness, is incapable of resisting
pressure, and consequently the caps lose their circular shape, which makes it
difficult to insert them in the sockets.
Now, by my invention, these and other disadvantages are overcome, as my
invention consists in making the caps of steel of a special shape, which will
render them sufficiently solid to withstand a considerable amount of pressure,
and to make the studs or projections integral therewith.
In carrying out my invention I cut from sheet steel, of suitable gauge, disc
blanks, and these blanks I subject to a drawing action in dies, as is now well
known, to produce cups.
From these cups, 1 stamp out the bottom in such a way as to leave a rounded
flange.
The caps thus formed are then placed in another die, and two long cuts in
each side are formed, the strip of metal left between the cuts being pressed
slightly outwards.
The cap is then taken to a finishing die, in which these strips are further
acted on, and are shaped to take the appearance generally of the soldered studs.
The cups thus formed are electroplated with copper or other metal, according
to the nature of the finish desired.
The holes formed by striking up the studs or projections will serve as venți-
lating holes for the cap, and other holes for that purpose are therefore rendered
unnecessary.
1
e
1 1000
NEWTON & SON,
Agents for the Applicant.
5 Improvements in and relating to Electric Incandescent Gas Ligung.
I, MAURICE LACHMAN, of 29A. Gillingham Street, Pimlico, London, S.W.,
Engineer, do hereby declare the nature of this invention and in what manner
[Price 8d.1

page_text: 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 produce the caps for electric incandescent
lamps in a simpler and more efficient manner than heretofore.
Hitherto, these caps, into which the bulbs have generally been secured by
plaster of Paris, have been formed of brass tubing, the external studs or pro-
jections, which are intended to lock into the bayonet slots of the socket, being
secured to the cap by soldering.
Brass tubing is expensive, and therefore, in order to reduce expense, the
tubing used is extremely thin, with the result that, being incapable of resisting
pressure, the caps lose their cylindrical shape, which makes it difficult to insert
them in the sockets. The thinness of the metal also renders it difficult to
satisfactorily secure the locking studs or projections thereto.
Now, in order to obviate these disadvantages, I employ thin soft sheet steel,
or other suitable metal, for the manufacture of these caps, and I make the
locking studs or projections integral therewith.
I also so form the cap, that it will retain its cylindrical form against any
ordinary pressure that may be applied to it.
In the accompanying drawing I have shown, in diagrammatic form, the
different stages through which the metal goes, to produce the desired result, the
particulars of each figure being given in full hereafter.
the
A is a disc blank, struck from the sheet of thin soft steel or other metal.
This blank A is placed in a suitable die, and is struck or drawn up, in
manner now well known, to the cup-shape shown in section at B.
This cup B is taken to another die, and the bottom is cut out, as shown in
the section at C, leaving a rounded flange C³.
The cap thus formed is then taken to another die, in which two peripherical
cuts are made on either side of the cup, and the strips left between the cuts are
slightly bulged outwards, as shown in the elevation D, at D', and the cross,
section E, the latter being taken on the dotted line of D, the punch for this
operation having the shape of an oblong plane and cutting only on the sides.
The cap is then taken to another die, where the said bulge D', produced as
before mentioned, is extended or drawn out into a loop form, and is closed in
laterally, as shown in the side elevation F', at F, and cross section G, the latter
being taken on the dotted line of F, thus forming the external studs or projec-
tions which are to fit into the bayonet slots of the socket or holder, thereby
giving, by elongation of bulge D₁, rigidity and strength, especially as said
bulges are both part of, and drawn from, the same base.
A slight modification in the mode of producing the external studs or projec-
tions, is shown in the side elevation H, and vertical section J. With the aid
of description given above, this modification will be clearly understood from
the figures, and further description is therefore unnecessary.
By the described mode of forming these studs or projections, holes or slots
will be left in the sides of the cap, which will serve as ventilation holes, and
special holes for that purpose will be unnecessary.
To prevent the oxidation or corrosion of the steel or other metal, it is pro-
posed to plate the caps with copper or other metal, according to the prevailing
character of the fittings, and the nature of the finish desired.
From the nature of the material used, these caps can be produced at a price
that it would be utterly impossible to produce them for, in brass tubing. With
respect to strength there is no comparison between these two metals, when the
brass is used as now in the form of a tube, while the rounded flange of the cap
gives the resisting power to lateral pressure which is entirely absent in a piece
of plain tube, and thus the cylindrical form of the cap is ensured at all times.
I may here remark, however, that while I prefer to use the soft sheet steel
for the purposes of my invention, I do not intend to confine myself to its use,

page_text: as I may produce the new form of cap with any other metal that is capable of
being drawn out or shaped in dies, if required.
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. Forming caps for incandescent electric lamp bulbs from sheet metal, with
the locking studs or projections formed of strips bulged out from the sides of
the caps, and shaped as herein shown and described.
2. Forming caps for incandescent electric lamp bulbs with a rounded flange
at the top of the cap, as and for the purpose set forth.
3. In producing caps for the bulbs of incandescent electric lamps, the use of
soft sheet steel, as set forth.
4. The mode of producing caps for the bulbs of incandescent electric lamps,
from disc blanks of metal in suitable discs, and consisting in forming the discs
into cups, stamping out the bottom of the cup, so as to leave a rounded flange,
and then striking up from the sides of the thus formed cap, and shaping, the
locking studs, as herein set forth.
5. As a new article of manufacture, cups for incandescent electric lamp bulbs
produced from soft sheet steel, having the locking studs integral therewith, and
a rounded flange at top, as herein shown and described, and for the purpose set
forth.
Dated this 15th day of December 1800
NEWTON & SON,
Agents for the Applicant.