IMPROVEMENTS IN THE MANUFACTURE 1 17.1 OF INCANDESCENT LAMPS AND IN APPARATUS TO BE USED IN CONNECTION THEREWITH
Year: 1883

page_text: LETTERS PATENT to William Crookes F.R.S. of Boy Court Ludgate Hill in the
.
City of London for an Invention of "IMPROVEMENTS IN THE MANUFACTURE
1
17.1
OF INCANDESCENT LAMPS AND IN APPARATUS TO BE USED IN CONNECTION
THEREWITH
"2
PROVISIONAL SPECIFICATION left by the said William Crookes at the
Office of the Commissioners of Patents on the 30th April 1883.
"
WILLIAM CROOKES F.R.S. of Boy Court Ludgate Hill in the City of London.
" IMPROVEMENTS IN THE MANUFACTURE OF INCANDESCENT LAMPS AND
APPARATUS TO BE USED IN CONNECTION THEREWITH.”
IN
This invention has for its object improvements in the manufacture of incandescent
lamps and in apparatus to be used in connection therewith.
In the manufacture of incandescent lamps as at present conducted it is usual to
mount the carbon filament in the first place upon a temporary support which holds
it whilst it is ignited in the presence of carbonaceous vapour for the purpose of
improving and adjusting its conductivity. After this process the filament is
transferred to the support which forms part of the lamp.
Now there is considerable risk of injury to the carbon filament in thus trans-
ferring it from one support to another. This risk I avoid by mounting the filament
in the first place upon its permanent support which forms part of the lamp and
then placing it with this support in a suitably contrived vessel from which the
air can be exhausted, and to which vapour can be admitted and where the filament
can be electrically ignited.
I prepare the lamp enclosure in the manner usually practiced by me. I divide
it into two parts and on the lower part of the lamp carrying the fork I mount the
filament.
I proceed to adjust the conductivity as described and then bring together the
two parts of the lamp and fuse them together at the blow pipe.
The lamp is exhausted and sealed off as usual
The lamp is finished in a small machine where its neck is set with plaster into a
wooden cup or cup of which the sides are of metal and the bottom of wood or of
other non conducting material. There are holes in the cup bottom to lead out the
conducting wires and others to receive two globular ended metal studs which form
the lamp terminals.

page_text: The glass is clamped in the machine between supports under the neck and a
moveable plunger which bears against the rounded end. The cup is set in place
upon a slide opposite the neck and it is filled with plaster. Thus by the movement
of the slide the cup is brought accurately to its place upon the neck and the con-
ducting wires are drawn out as the cup passes to its place. The projection on the
neck of the lamp left where the connection with the air pump is made is enveloped
in paper to preserve it from injury by the contraction of the plaster in setting.
There is a cavity formed in the cup bottom.to-receive this projection.
The lamp being thus mounted it only remains to screw in the lamp terininals
down on to the ends of the conducting wires forming therewith a good electrical
connection and the lamp is finished.
To receive these lamps I provide wooden or other non conducting sockets which
are fixed wherever the lamps are required for use. The socket and the lamp foot
are adapted to screw together.
in
:
The socket has within it a pair of horn like springs to which the wires for the
supply of the lamp are brought and when the lamp is screwed into the socket its
terminals come against these springs and are pressed by them, thus good electrical
communication is established. These contacts may however be separated at any
time when it may be desired to extinguish the lamp simply by turning the lamp
partly round in the socket. By the application of an additional spring, or by other
means a wide separation between the studs on the lamp and the contact springs is
ensured when the lamp circuit is opened.
Another way of supplying current to a lamp which is frequently convenient is
to suspend it from a button formed of insulating material and provided with two
metal springs. The button itself hangs by conducting wires which are in electrical
connection with the springs. The lamp terminals have holes in them and the ends
of the springs entering these both hold the lamp securely and supply it with
current.
Sometimes I connect the lamps directly to conducting cords passing to the
ceiling of a room. To fasten the wires securely the lamp terininals may be provided
with little levers having eccentric ends so that when the levers are turned they nip
the wires inserted between them and their supports.
The conducting cords descends from rosettes on the ceiling. cylindrical boss
of insulating material stands out from the centre of the rosette and on the sides of
it there are pieces of metal connected with the wires supplying the current; these
wires are laid in mouldings along the ceiling. The mouldings have removable caps.
The conducting cords by which the lamps hang are connected with the boss of the
rosette by inserting the ends of the wires into holes in the metal pieces and drawing
a ring or slider down over them.
Where connections have to be made at a side wall I provide two separate metal
studs or nipples each with a slider upon it. I insert each wire into a hole in the
side of the stud or nipple and draw the slider forward over it. I complete each
circuit carrying a set of lamps through a simple key consisting of two bent wires
fixed on a base of wood. One part of the key consists of an arm the outer end of
which is readily moveable in consequence of the elasticity of the metal and when
moved tends to return. The other part which also is readily movable by the
yielding of the wire is formed with an eye and also has a button to receive the
pressure of the finger. When the arm on one part is depressed the eye of the other
part engages with it and the circuit is complete.
Pressure on the button removes the eye, the arm springs away and leaves the
circuit open, without any danger of leaving an arc.
Thus the circuit is closed and opened at pleasure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Crookes in the Great Seal Patent Office on the
30th October 1883.
WILLIAM CROOKES F.R.S. of Boy Court Ludgate Hill in the City of London
"IMPROVEMENTS IN THE MANUFACTURE OF INCANDESCENT LAMPS AND IN
APPARATUS TO BE USED IN CONNECTION THEREWITH"
In the manufacture of incandescent lamps as at present conducted it is usual to
mount the carbon filament in the first place on a temporary support which holds
it whilst it is ignited in the presence of carbonaceous vapour, for the purpose of
improving and adjusting its conductivity. After this process the filament is
transferred to the support which forms part of the lamp.
Now there is considerable risk of injury to the carbon filament in thus trans-
ferring it from one support to another. This risk I avoid by mounting the filament
in the first place upon its permanent support which forms part of the lamp, and
then placing it with this support in a suitably contrived vessel from which the air
can be exhausted and to which vapour can be admitted and where the filament can
be electrically ignited.
I preferably prepare the lamp enclosure in the manner usually practiced by me
and described in the Specification of the Letters Patent granted to me August 31st
1881 N° 3799, and after it is divided into two parts I mount the filament on the
lower part of the lamp carrying the fork as it is represented in Figure 1 of the
annexed Drawings. But the same course can be adopted when other methods of
manufacturing the glass enclosure are employed. When the filament has been
mounted in the manner in which it is intended to remain when the lamp is finished,
I take the filament and the part of the lamp on which it is mounted, and placé
the whole in the chamber described in the Specifications of the Letters Patent
granted to me August 31st 1881 N° 3799 and September 6th 1882 N° 4238 fixing
the terminals of the lamp to the fixed terminals in the chamber and proceed to
adjust the conductivity in the manner described in such Specification.
The lamp is jointed together, exhausted and sealed off as usual.
The lamp is finished in a small machine where its neck is set with plaster into
a wooden cup (see Figure 2) or cap of which the sides are of metal and the bottom
of wood as represented in section at Figure 3. Any other suitable non conducting
material can of course be used instead of wood. There are holes in the cup bottom
to lead out the conducting wires, and others to receive two globular ended metal
studs which form the lamp terminals.
The glass is clamped in the machine between supports under the neck and a
moveable plunger which bears against the rounded end. The cup or cap is set in
place upon a slide opposite the neck, and it is filled with semi-liquid plaster. Then
by the movement of the slide the cup is brought accurately to its place upon
the neck and the conducting wires are drawn up tight as the cup passes to its
place.
This apparatus with a lamp in it is represented by Figure 4 of the Drawings
annexed.
The projection on the neck of the lamp marked a in the Figures 1 and 4. left
where the connection with the air pump is made (if the lamp is exhausted from
that end) is loosely enveloped in paper or similar material to prevent contact
between it and the plaster and so to preserve it from injury by the contraction or
expansion of the plaster in setting. There is a cavity formed in the cup bottom
at b in Figures 2 and 5 to receive this projection.

page_text: The lamp being thus mounted it only remains to screw in the lamp terminals
down onto the ends of the conducting wires forming therewith a good electrical
connection and the lamp is finished. I prefer to insert a lead washer between the
wood and the wire. The conducting wires are brought for this purpose from the
holes through which they come out and are twisted round the shank of the
terminals and the terminals are then screwed down upon them.
Figure 5 is a side elevation of a lamp thus completed. c, c, are the screw
terminals, one of them is shown separate at Figure 6. The spherical part of the
terminal perforated.
Figure 7 shows a similar lamp in which the cup is partly of brass as in Figure 3
this is the form which I prefer.
To receive these lamps I provide sockets of wood or other non-conducting
substance as is represented in Figures 8 which are fixed wherever the lamps are
required for use. The socket and the lamp foot are adapted to screw together as
shown by Figure 9.
The socket has within it a pair of hornlike springs in the shape of a segment
say each of about one third of a circular annulus, bent upwards from the base of
the hollow to which one end of it is fixed.
The wires for the supply of the lamp are brought to the springs and when the
lamp is screwed into the socket its terminals cc come against these springs and
are pressed by them, thus good electrical communication is established. These
contacts may however be separated at any time when it may be desired to
extinguish the lamp, simply by turning the lamp partly round in its socket. By
the application of an additional spring or by other means, a wide separation between
the studs on the lamp and the contact springs may be secured when the lamp
circuit is opened.
Another way of supplying current to a lamp which is frequently convenient is
to suspend it from a button or other small support formed of insulating material
and provided with two metal springs as shown in the drawings Figures 10.
The extremities of the springs point inwards or outwards according as the
distance between them in the position of rest is less or greater than the distance
between the terminals. The button itself hangs by conducting wires, each of which
is in electrical connection with one of the springs. The lamp terminals as already
stated have holes in them, and the ends of the springs entering these both hold the
lamp securely and supply it with current.
Sometimes I connect the lamps or their sockets or the aforesaid buttons directly
to conducting cords passing to the ceiling of a room. To fasten the wires securely
the lamp terminals may be provided with little levers having cam-shaped or
eccentric ends as shown in the drawings Figures 11 working in a slot in the
terminal so that when the levers are turned they nip the wires inserted between
them and the bottom of the slot. In Figures 11 the little levers are marked e e.
When the levers are laid down horizontally there is room for the end of the wire
to be entered between the end of the lever and the support to which the lever is
jointed; but when the lever is turned up into a vertical position the wire becomes
nipped and a good electrical connection is established.
Figures 12 show the arrangements for the connection of the conducting cords
at the ceiling of the room or chamber. The conducting cords descend froin rosettes
or ornaments a in the ceiling. A cylindrical boss b of insulating material stands
out from the centre of the rosette and on the sides of it there are pieces of metal b
connected with the wires d supplying the current: these views are laid in
mouldings along the ceiling. The mouldings have removable strips. The con-
ducting cords e by which the lamps hang have pieces of stiff wire about two
inches long soldered to them and are connected with the boss of the rosette by
inserting the ends of the wires bent at right angles into holes in the metal
pieces band drawing a non-conducting ring or slider e¹ down over them as shewn
in the drawings. Where connections have to be made at a side wall I provide two,

page_text: separate metal studs or nipples each with a slider upon it: I insert each wire
bent at right angles into a hole in the side of the stud or nipple and draw the
slider forward over it.
This arrangement is shewn by Figures 13.
ff are two metal studs receiving the current by the wires g. g.
grooved on the upper side and the groove terminates in the hole.
Each stud is
The wire lies
in the groove its end entering the hole where the slider when drawn forward
keeps it..
I complete each circuit carrying a set of lamps through a simple key one formn"
of which is shown by Figures 14. It consists of two bent wires a and b fixed in
a base of wood slate or other non-conducting material one part of the key a
consists of an arm the outer end of which is readily moveable in consequence of
the elasticity of the metal, and when moved tends to return. The other part b
which also is readily moveable by the yielding of the wire is formed with an eye
and also has a button to receive the pressure of the finger. When the arm on one
part is depressed, the eye of the other part engages with it and the circuit is
complete.
Pressure on the button removes the eye, the arm springs away and leaves the
circuit open without any danger of leaving an arc.
Thus the circuit is closed and opened at pleasure.
Having now particularly described and ascertained the nature of my said
invention and the manner in which the same is to be performed I would have it
known that what I claim to have invented is as follows:-
First. Mounting the filament upon that portion of the lamp to which it is to
reinain permanently attached prior to adjusting its resistance and performing such.
adjustment by placing the lower portion of the lamp enclosure, with the filament
permanently fixed thereto in a chamber in which it is electrically ignited in
suitable vapour or gas substantially as herein described.
Secondly. The method of and apparatus for affixing the cup or cap to the lamp
substantially as herein described.
Thirdly. Covering the projection on the neck, left where the connection with
the air pump is made, with paper or similar material to protect it from injury
from the plaster during the manufacture of the lamp substantially as herein
described.
Fourthly.--The lamp terminals substantially as herein described, and consisting
of a screw with hemispherical or nearly spherical perforated head.
Fifthly. The construction and use of lamp sockets to which the lamps screw,
and which are fitted with hornlike springs, so that good electrical contact between
the lamp terminals and the leads coming to the sockets, is made by turning the
lamp in the socket and is broken in a similar manner, substantially as herein
described.
'
Sixthly. The method of suspending the lamp from two springs turned up at
the ends, so as to enter perforations in the lamp terminals, substantially as herein
described.
Seventhly. The springs bent at the ends affixed at one end to a button
suspended by a conducting cord and springing into perforations in the lamp
terminals substantially as berein described.
Eighthly. The lamp terminals consisting of little levers with eccentric or cam-
like movement, for gripping the conducting wires, substantially as herein
described.
Ninthly. The arrangement for the convenient attachment and the easy removal
of the conducting wires to or from the leading wires at a boss or rosette affixed
to the ceiling or the walls substantially as herein described.
Tenthly. The construction of terminals to the leads affixed to a side wall or
ceiling with sliders to ensure good secure contact, substantially as herein
described.

page_text: Eleventhly. The key with spring arrangement for effectively making and
breaking the circuit without permitting the formation of an electric arc
substantially as herein described.
In witness whereof I the said William Crookes have hereunto set my hand and
seal this twenty seventh day of October in the year of our Lord One thousand
eight hundred and eighty three.
WILLIAM CROOKES. (LS.)