Improvements in the Manufacture of Metal Bases for Electric Incandescence Lamps.
Year: 1898

page_text: Date of Application, 9th Mar., 1898-Accepted, 9th Apr., 1898
[Communicated from abroad by LA COMPAGNIE GENERALE DES LAMPES A
INCANDESCENCE, of 5, Rue Boudreau, Paris, in the Republic of France.]
Improvements in the Manufacture of Metal Bases for Electric
Incandescence 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:―
This invention relates to improved means for forming the projections or nipples for
the bayonet joint connection between the bases and sockets of electric incandescent
lamps.
The projections or nipples employed in these lamp bases have heretofore been
formed of solid pins, either riveted or soldered to the brass ring, forming the body
of the lamp base.
Another means, sometimes employed is to cut two tongues out of the brass ring
and to so fold these tongues as to make them normal to the axis of the base. In
order, however, that on using this method a sufficient rigidity may be obtained, it
is necessary that metal of a comparatively great thickness be employed for the
bottom.
In carrying out my said invention I employ means, which gives the best results,
since, without in any way deteriorating the metal, I can produce a nipple, project-
ing to such an extent, as to firmly secure the lamp in its socket. The projection
and shape, offered by the nipple is of the highest importance, since otherwise the
lamp will not be securely retained in the socket.
The nipple or projection formed according to the present invention is of a more
practical shape than those heretofore made."
In the accompanying drawing,
Figure 1 is a section of a base before being treated according to my invention,
Figure 2 represents a section of a base after it has been submitted to the first
operation.
Figure 3 shows the same after the second operation, and
Figure 4 shows the final form of the base.
For producing a nipple according to my invention I employ a tool, by which the
said nipple receives the desired shape by a series of successive operations.
In carrying my invention into practice I place the base over a suitable male
die upon which a female die or matrix of appropriate shape is adapted to be
pressed.
I thus produce the form of nipple shown in Figure 2; then by means of a second
similar operation with a die and matrix of a slightly more tapering or pointed
shape, I produce upon the base the form shown in Figure 3; and lastly by a
third operation with a die and matrix of a slightly modified form I obtain the final
form of the nipples or projections shown in Figure 4.

page_text: Thus a nipple of suitable shape, extending more than 2 millimetres, is produced
without the metal being pierced, and without the soldering, rivetting or cutting out
of the metal of the base. It is obvious, that this nipple-of a length of 2 millimetres
is of great importance. In fact, were a nipple, projecting only one millimetre or
less, employed, the lamp would not be securely retained in most of the lamp sockets,
at present on the market, by reason of the variation of the diameter of these sockets.
This improved lamp-base may be made of brass, copper or any other suitable
metal.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is:-
1. A base for electric incandescent lamps, produced by means of suitably adapted
matrices, applied to the lamp-base in several successive operations, whereby, as
before stated, projections or nipples, extending at least 2½ millimetres, can be
formed thereon.
2. A base for electric incandescent lamps having projections or nipples for the
connection of such lamps, manufactured in the manner above described.
J
Dated this 9th day of March 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.