IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS
Year: 1882

page_text: LETTERS PATENT to Stephen Henry Emmens of 8 Argyll Street, in the
County of Middlesex, Actuary. for an invention of IMPROVEMENTS IN
INCANDESCENT ELECTRIC LAMPS
PROVISIONAL SPECIFICATION left by the said Stephen Henry Emmens at
the Office of the Commissioners of Patents on the 18th May 1882.
STEPHEN HENRY EMMENS, of 8 Argyle [Argyll] Street in the County of Middlesex,
Actuary "IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS'
"
My invention relates to electric lamps dependent for their luminosity upon the
incandescence of a bridge or conductor of carbon or other suitable substance of
high electrical resistance, in vacuo, or in petroleum, bisulphide of carbon or other
suitable gas or vapor.-It is designed to give a more diffused light than is
obtainable from the known types of lamps, and to afford a means for the regulation
of the quantity of light from any single lamp.
These objects I effect by enclosing in each bulb or globe a series of small
incandescing conductors in place of the single incandeseing conductor hitherto
used. This series is conveniently arranged in continuous circuit and around a
circle and thus affords an equable and well diffused light. By the employment of
a suitable switch or short circuiting device interposed between the lamp and the
leading wires, one or more of the incandescing conductors may be cut out, and the
luminosity of the lamp thus regulated

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Stephen Henry Emmens in the Great Seal Patent Office on the
18th November 1882.
STEPHEN HENRY EMMENS of 8 Argyll Street in the County of Middlesex,
Actuary IMPROVEMENTS IN INCANDESCENT ELECTRIC LAMPS
My invention relates to electric lamps dependent for their luminosity upon the
incandescence of bridges or conductors of carbon or other suitable substance of
high electrical resistance, in vacuo, or in the attenuated vapour of petroleum, or
bisulphide of carbon, or other suitable gas or vapour. It is designed by improve-
ments in the bridges and conductors to give a more diffused light than is obtainable
from the known types of lamps, and by improvements in switching and short
circuiting to afford a means for the regulation of the quantity, without materially
changing the colour of the light from any single lamp.
These objects I effect by enclosing in each bulb or globe a series of incandescing
conductors, either divided into distinct filaments, or into series on the same
conductor by perforations or by various shunt connections, in place of the single
incandescing conductor hitherto used.
The series may be arranged in either continuous or parallel circuit and thus
affords an equable and well diffused light. By the employment of suitable short
circuiting devices, or a switch interposed between the lamp bridges and the leading
wires, one or more of the incandescing parts, or of the subdivided portions of
them, may be cut out, and the luminosity of the lamp thus regulated without
material change of colour in the light.
In order that my invention may be the better understood, I now proceed to
describe the drawings hereunto annexed, reference being had to the letters and
figures marked thereon
Figures 1 to 8 show samples of the forms in which I make my conductors,
which are composed of carbonised vegetable parchment, or ivory, or fibre, or may
be formed of compressed carbon moulded or cut into the desired shape, or of
Indian Ink or other carbon paint, dried on the surface of a non-conductor. It will
be seen that some of my conductors Nos 5, 6 and 7 are perforated by holes or slots,
so as to render the reduced sections between the holes or slots a series of conductors
of considerable resistance, thereby producing in them white hot incandescence.
My bridges are supported in bulbs, globes, or tubes, of glass by holders of
platinum, or other suitable wire or ribbon, as shown in Figures 9 to 14.
The holders are hermetically sealed or fused in the wall or neck of the vacuum
globe in the usual way, so that the projecting external portions of the holders can
be electrically connected to the line wires. The various arrangements of my
bridges in series are shown in Figures 15 to 20, divided into parallel circuits in
Figures 15 and 16, into continuous circuit in Figure 17, and into detached or shunt
circuits in Figures 18, 19 and 20.
In order to effect the regulation of the quantity of light in any lamp without
materially changing the incandescent intensity of the remaining part in circuit, I
cause the bridge holders to terminate either in loops, which are caught by hooks
communicating with the leading wires, or in wires or rods, which plunge into holes
in the supporting plugs or sockets, and are there brought into connection with
the leading wires by set screws or switches, as shown in Figures 25. 26. 27. 30
and 31.
As for example taking the arrangement shown at Figure 31 the main A may be
conveniently led through the tubes of the gasolier or electrolier up the centre of

page_text: the holder B, hereinafter more fully described, by the set screw C, and branch wires
or plates C¹. Electrical contact is made with the two incandescent filaments D D¹
in parallel or alternative circuit.
The further ends of D and D₁ are united at E, and thence communicate with
the metallic casing F, and thus in any convenient manner to earth, or to a return
wire.
If either of the two set screws G G₁are loosened, they will cut out of circuit
the filaments D and D' respectively, so that either filament or both may be thus
extinguished, the incandescent colour not being materially altered, till the whole is
extinguished.
The lamp is supported by a collar embracing its throat, and either fitting on the
plug or socket, or connected therewith by two or more legs working in spiral
springs, as shown in Figures 21. 22. 28. 30 In some cases I may alternatively
keep the lamp in its place by a set screw, or by one or more springs, as shown in
Figures 29. 32. and 33.
The connection of the leading wire through a central hole in the plug or socket,
electrical contact being there made by a set screw, has the advantage of enabling
the socket to be freely turned on the end of the line wire to screw it to brackets or
other fittings.
And having now fully described and ascertained the nature of my said
invention, be it known that what I consider novel and desire to protect by letters
patent is :-
1st The combination with an incandescent Electric lamp of a carbonized ivory
bridge
2nd The combination with an incandescent electric lamp of a bridge composed of
carbonaceous material in the form of a perforated disc or other flat shape with
especial reference to Figures 5. 6. and 7.
3rd. The combination with an incandescent electric lamp of a bridge composed of
a film of dried Indian ink or other carbonaceous material on the surface of a
non-conducting substance
4th The combination in an incandescent electric lamp of two or more such
bridges as a means of diffusing the light, and of short circuiting set screws or
switches, substantially as and for the purposes described with reference to
Figure 31.
5th In an incandescent electric lamp the construction of a holder for such bridges,
composed of a whole or slotted spiral or waved line of platinum or other suitable
wire or ribbon substantially as and for the purposes specified.
6th In an incandescent electric lamp the construction of a support consisting of
a collar with legs plunging into holes in a plug or socket or into tubes affixed to a
collar encircling such plug or socket, substantially as and for the purposes specified.
7th. In an incandescent electric lamp the combination of a spiral spring encircling
the leg of such collar as a means of maintaining contact for the transmission of the
electric current to the bridges substantially as and for the purposes specified with
reference to Figures 21 and 22.
8th In an incandescent electric lamp the construction of a support consisting of
a collar with legs attached, which are either fastened to the plug or socket by set-
screws, or act as spring clips to grip the same substantially as and for the purposes
specified with reference to Figures 23 and 24.
9th In an incandescent electric lamp the construction of a non-conducting plug
or socket, into which the leading wire enters at its central axis and the bridge
wires at other convenient points, the necessary electrical contact being effected by
set screws from the exterior substantially as described in reference to Figures 26.
27. 28. 29. 30 and 31.
10th In an incandescent electric lamp the combination of a set screw and nut
between the lamp and socket, with hooks for making contact between the lamp
bridges and the line wires, substantially as specified with reference to Figure 29
11.th In an incandescent electric lamp the combination with a spring or springs,

page_text: either plain or spiral, and fixed between the lamp and the socket, of books in the
said socket for effecting and maintaining electrical contact between the lamp bridges
and the line wires in reference to Figures 28, 30, 32 and 33.
In witness whereof I the said Stephen Henry Emmens have hereunto set
my hand and seal this sixteenth day of November in the year of our
Lord One thousand eight hundred and eighty-two.
Witness.
S. P. WILDING.
23 Rood Lane, Fenchurch-street.
London. E.C.
Patent Agent
STEPHEN H. EMMENS (L.S.)