AN IMPROVED METHOD FOR THE CONSTRUCTION OF INCANDESCENT ELECTRIO LAMPS
Year: 1886

page_text: Date of Application, 19th June, 1886.
Complete Left, 19th Apr., 1887.
Complete Accepted, 31st May, 1887.
ALFRED SWAN, Low Fell, Gateshead Co. Durham, Engineer do hereby declare the
nature of my invention for AN IMPROVED METHOD FOR THE CONSTRUCTION OF
INCANDESCENT ELECTRIO LAMPS to be as follows:-
My Invention has for its object the simplyfying of the Construction of Incandescent
Electric Lamps.
Hitherto the receiver of such lamps has been made wholly of Glass, into which the
leading wires have been directly sealed, this peculiar construction of the lamp
involving the necessity of fittings for it of a special and extraneous character. For
the purpose last mentioned various devices have been resorted to; one amongst the
number being a brass socket, slotted and otherwise adapted for a cap specially made
to fit the neck of the lamp, and to be affixed to it by means of cement.
My present invention supersedes the necessity for this last mentioned process, inasmuch
as I make the cap in question an integral part of the Lamp itself, as follows, I take a
cap of a certain form (preferably of the form and of the material known as "Vitrite,")
in which the necessary contact pieces are already embedded, I mount the carbon
filament, or other luminant material, in the said cap by connecting to the aforesaid
contact pieces therein; the Platinum or other wires carrying the said luminant, using
for this purpose solder, amalgam, or other approved cement.
Then to the rim, or flange of the said cap, I join the enclosing glass bulb, sealing
the two together by the blow-pipe, so as to make a perfectly air-tight joint.
The lamp is then in a form to be exhausted by the usual process and in the ordinary
manner.
Dated this Tighteenth day of June 1886

page_text: Electric Lamps.
I, ALFRED SWAN of Low Fell Gateshvad Durham 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 has for its object the simplification of the construction of incandescent
Electric lamps whereby the cap or fitting by which the lamp is secured to the support
is formed as an integral part of the vacuum chamber or bulb itself instead of being
separate from a bulb or vacuum chambor made wholly of glass into which the leading
wires are directly sealed as has been hitherto the case. The separate fittings for the
lamps or bulbs made in this latter manner have been of various kinds, such for
example as a socket of brass, slotted and adapted to receive and hold a cap made
separately from the bulb to fit the neck of the bulb and fixed thereto by cemont.
My Invention supersedes the use of the usual fittings made separately from the
bulb as I make the aforesaid cap or its equivalent an integral part of the bulb itself
which I effect as follows:
I take a cap or its equivalent preferably mado of the material known as " Vitrite,"
I form this cap in moulds to give it the requisite shape, for example, that shewn at a
in clevation section and plan in Figures 1, 2 and 3 respectively of the accompanying
drawings, there being in the opposite sides bayonet slots, one of which is shown at a²
for the reception of projections on the part or support to which the bulb is to be
secured. I place in the mould contact-pieces b, in or to which the terminal wires c,
are soldered or otherwise secured, and when the material of the cap is moulded, the
said pieces bare secured therein. I have shewn the contact-pieces b, as being cap or
cup-shaped, but I do not limit myself to that shape nor do I limit myself to the
bayonet grooves a² in the sides of the part a as any suitable means for fastening this
part to the support to which it is to be secured may be adopted. I mount and secure
the carbon filament or other incandescing medium in or to the wires c which may be
effected in any suitable or ordinary way. I then take a portion of a glass bulb as
shewn at d, in Figure 4, and I join the edge thereof to the rim of the cap a,
(at a) which can be effected by means of a blow-pipe so as to make a preferably air-
tight joint. The compound bulb thus made is shewn in figure 5 which is a section
thereof. The cap a, as shewn has a nipple a' through which is an opening by which
the air is exhausted from the bulb,. after which the nipple is sealed as shewn in
Figure 5, to secure the vacuum. Thus I am enabled to dispense with the necessity
for the objectionable nipple piece at the top of the bulb, which is used in the lamps,
as ordinarily made.
I prefer to use "Vitrite," for the cap or cup-part a, as it is capable of being
moulded or pressed into shape when heated, and as it is a good insulator and also as
it can be very efficiently sealed to the glass portion of the bulb and as its co-efficient
1

page_text: of expansion is or can be made the same as that of brass or other base metal, I can
use brass or other base metal for the contact-pieces b, without liability of injury to the
vacuum in the bulb and the said contact-pieces b, can be of large size and therefore
are less liable to over-heating than are the ordinary platinum wires sealed into the
glass in the usual way. The outer parts of b, form the contacts for the current from
the external circuit to the lamp.
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 :-
First. The manufacture or construction of incandescent Electric lamps, wherein the
cap or part containing the contact-pieces and by which the lamp is secured to, and
contact is made with, the support, is inade an integral part of or with the lamp proper,
bulb, or vacuum-chainber, substantially as described.
Second. The manufacture of incandescent Electric lamps of a part of Glass and a
part of "Vitrite," or the like, sealed together, the last named part having large
contacts scaled therein, to the inner sides of which the supports of the incandescing
medium are affixed substantially as described.