IMPROVEMENTS IN ELECTRIC-LAMPS
Year: 1881

page_text: LETTERS PATENT to Richard Harrison, of Granger Street, in the Borough and
County of Newcastle on Tyne, Engineer, and Charles Blagburn, of Dean
Street, in Newcastle on Tynė aforesaid, Engineer, for an Invention of
"IMPROVEMENTS IN ELECTRIC-LAMPS."
PROVISIONAL SPECIFICATION left by the said Richard Harrison and
Charles Blagburn at the Office of the Commissioners of Patents on the
26th March 1881.
RICHARD HARRISON, of Grainger Street, in the Borough and County of
Newcastle on Tyne, Engineer, and CHARLES BLAGBURN, of Dean Street, in
Newcastle on Tyne aforesaid, Engineer. "IMPROVEMENTS IN ELECTRIC LAMPS."
Our Invention relates to that construction of electric lamps in which a carbon
pole is kept continuously in contact with a second pole of suitable conducting
material, and of larger sectional area than the former so as to produce light by the
incandescence of the first named pole. According to our present improvements
the forward feed of the smaller carbon and the conveyance of the electric current
to or from the same is effected by means of two rollers of suitable conducting
material, and by preference grooved, one or both of which are mounted upon
pivotted arms, and to which rotation is imparted as follows:-On the axes of the
rollers are grooved pullies, over which passes a metallic cord or chain, the two ends
of which are attached to a weight or weights, and which is then led over the said
pullies, and thence under a third pulley carried by the holder of the said carbon.
Thus the weight in descending and drawing the cord with it will cause the contact
rollers to be rotated thereby, so as to tend to raise the carbon, while at the same.
time the pull of the cord upon the pulley on the carbon holder will also tend to
raise the carbon.
The rollers may be made to nip the carbons sufficiently either by placing the
pivotted arms on which they are mounted at such an inclination towards the
carbon that the pull of the cord on the pullies tends to pull the arms and rollers

page_text: or one of them with sufficient force against the carbon; or the arms carrying the
rollers may have weighted extentions or be acted upon by weighted rods so as to
pull them against the surface of the carbon. Or according to another modification
instead of mounting the pullies on the axes of the contact rollers they may be
mounted upon rods connected to the arms of the rollers in such a manner that the
pull of the cord passing over the said pullies will cause the rollers to be pulled
against the carbon so as to nip it. In this case the raising of the carbon is effected
only by the weighted cord, the rollers merely acting as contacts. Or according to
another modification the said rollers may act only as feed rollers for the carbon,
while the electrical contact for the latter is furnished by separate contact pieces
acted upon by springs or weights. It will be evident that lamps of the above
described construction may be arranged with the carbons in any desired
position.
For the purpose of short circuiting the before described lamps when more than
one are in circuit the larger pole is electrically connected by a suitable conductor
with a contact piece, with which a second contact piece upon the internal or
external weight in electrical connection with the smaller pole is brought into
contact when such smaller pole is consumed, and such contacts may be arranged to
throw a resistance into circuit..
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Richard Harrison and Charles Blagburn in the Great Seal Patent
Office on the 26th September 1881.
RICHARD HARRISON, of Grainger Street, in the Borough and County of
Newcastle on Tyne, Engineer, and CHARLES BLAGBURN, of Dean Street, in
Newcastle on Tyne aforesaid, Engineer. "IMPROVEMENTS IN ELECTRIC LAMPS."
Our Invention relates to that construction of electric lamps in which a carbon
pole is kept continuously in contact with a second pole of suitable conducting
material, and of larger sectional area than the former so as to produce light by the
incandescence of the first-named pole. According to our present improvements
the forward feed of the smaller carbon and the conveyance of the electric current
to or from the same is effected by means of two rollers of suitable conducting
material, and by preference grooved, one or both of which are mounted upon
pivotted arms, and to which rotation is imparted as follows:-On the axes of the
rollers are grooved pullies, over which passes a metallic cord or chain, the two ends
of which are attached to a weight or weights, and which is then led over the said
pullies; and thence under a third pulley carried by the holder of the said carbon.
Thus the weight in descending and drawing the cord with it will cause the contact
rollers to be rotated thereby, so as to tend to raise the carbon, while at the same
time the pull of the cord upon the pulley on the carbon holder will also tend to
raise the carbon.

page_text: The rollers may be made to nip the carbons sufficiently either by placing the
pivotted arms on which they are mounted at such an inclination towards the
carbon that the pull of the cord on the pullies tends to pull the arms and rollers
or one of them with sufficient force against the carbon; or the arms carrying the
rollers may have weighted extensions, or be acted upon by weighted rods so as to
pull them against the surface of the carbon. Or according to another modification
instead of mounting the pullies on the axes of the contact rollers they may be
mounted upon rods connected to the arms of the rollers in such a manner that the
pull of the cord passing over the said pullies will cause the rollers to be pulled
against the carbon so as to nip it. In this case the raising of the carbon is effected
only by the weighted cord, the rollers merely acting as contacts. Or according to
another modification the said rollers may act only as feed rollers for the carbon,
while the electrical contact for the latter is furnished by separate contact pieces
acted upon by springs or weights. It will be evident that lamps of the above
described construction may be arranged with the carbons in any desired
position.
For the purpose of short circuiting the before described lamps when more than
one are in circuit, the larger pole is electrically connected by a suitable conductor
with a contact piece, with which a second contact piece upon the internal or
external weight in electrical connection with the smaller pole is brought into
contact when such smaller pole is consumed, and such contacts may be arranged to
throw a resistance into circuit.
Fig. 1 of the accompanying Drawings shews in elevation partly sectional an
electric lamp according to our Invention, in which the carbon rod Cis fed upwards
against the block B, the light being produced by incandescence of the thin part of
the carbon rod next to B; Fig. 2 is a plan shewing the feed rollers; Fig. 3 is a
sectional plan on X, X, and Fig. 4 is a sectional plan on Y, Y. The framing of
the lamp consists of two bent tubes or rods A, A¹, the upper ends of which are
connected respectively to the conductors L, L', which may be as shewn wire cords
suspending the lamp, the ends of these cords being somewhat bulged and clamped
by the screw sockets a, a¹. The block B is in metallic connection with the one
frame A, and the tube D containing the carbon C and carrying its feeding
mechanism is in metallic connection with the other frame A¹. Vulcanite or other
suitable insulating material is introduced at a³ the upper junction of the frames,
and at a³ there lower junction. The tube D is a double one, and both the inner
and the outer tube have longitudinal slits on each side; the outer tube can be
turned about one quarter of a revolution round the inner tube by means of a
milled head d of non-conducting material at its lower end, the inner tube being
held by an insulated head d. In one position of the outer tube when its slits
coincide. with those of the inner tube, access is given to introduce or remove the
carbon C, and in this position a stud or spring at d³ projecting from the outer tube
is brought into contact with a stud or spring projecting from the socket of the
frame A, thus short circuiting the electric current. When the outer tube is turned
one quarter round so that it covers the slits of the inner tube, as shewn in Fig. 4,
the contact at d³ is broken, and then the current from L¹ must pass through A',
the tube D, the carbon C, the block B, to A and L, or in the reverse direction.
The insulation of the parts at d and d' to which the hands are applied for turning
the outer tube protects the operator from shock. At the upper end of the tube D
two rollers E and E' are mounted on inclined arms hinged to the tube. One of
the armis, as that of E¹ may be adjusted by a setting screw e¹ having a groove to
receive a transverse pin, so that by turning the screw in one direction or the other
the roller E' can be adjusted nearer to or farther from the axis of the tube D.
On the opposite sides of the rollers E, E', there are grooves to receive wire cords
or chains which are attached each at one end to a weight F that can slide freely
up and down the tube D, and at the other end to a tube G attached to a ribbed
guide H which can slide freely within the tube D. The carbon C is inserted in the
upper end of the tube G and rests on a cross pin. The weight F descending causes

page_text: the carbon to rise, at the same time turning the rollers E, E', and pressing the one
of them E, which is moveable, against the one side of the carbon C, whilst the
other roller E¹ forms an abutment for the carbon on its other side. By dispensing
with the setting screw e¹, both rollers E and E' being moveable would be pressed
against the carbon with a like result. The rollers E, E¹, instead of being made
of metal, may be made of carbon clamped between metallic cheeks. A pin K
passes through the insulating material at the lower end of the frame A and
projects into the tube D, but clear thereof in such a position that when the
carbon C is nearly all consumed, another pin K' projecting from G has so far been
raised as to come into contact with K, thus short circuiting the electric current.
Although we have shown a lamp with the carbon fed upwards by the descent
of the weight F, it is to be understood that the lamp might be inverted, or
placed horizontally or inclined, in which case the feeding cords or chains that pass
over the pullies E, E, would be passed also over pullies at the end of the tube D,
and attached to a suitable weight F.
Having thus described the nature of our Invention, and in what manner the
same is to be performed, we claim,―
First. The construction of incandescent electric lamp in which a carbon rod is
kept continously in conta with a block or pole, being fed towards it between two
grooved rollers near its point, which are caused to turn and to press against the
carbon by cords attached to a descending weight, substantially as herein
described.
Second. In an electric lamp, such as is referred to in the preceding claim, short
circuiting the current when the carbon constituting the one pole is exhausted by
the contact of the carbon holder with a pin that is in metallic connection with
the other pole, substantially as herein described.
In witness whereof, I the said Richard Harrison, have hereunto set my
hand and seal this Twenty-third day of September, in the year of our
Lord One thousand eight hundred and eighty one..
P HADDISON