Improvements in Arc Lamps.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in Arc Lamps.
I, GEORGE HILL, of the Firm of George Hill and Company, of Trafford
Electric Works, Manchester, in the County of Lancaster, Electrical Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in arc lamps and the object of my
improvements is to govern the movements of the carbons so as to strike and
maintain a uniform arc.
I accomplish this object by an improved form of brake hereinafter described.
I mount upon the frame of the lamp or upon a suitable bracket a brake wheel
and to the bracket or other stationary part I pivot eccentrically but preferably as
near as convenient to the centre of the wheel an arm the other end of which
projects beyond the rim of the brake wheel and lies in the same plane; a chamber
is formed in the projecting portion of the arm radial to the axis of its pivot or
thereabouts and a stud with an enlarged end which forms the brake block is
placed in the chamber where it is surrounded by a coiled or other spring; the
small end of the stud passes through a hole at the back of the chamber and is
threaded to receive a milled screw head and lock nut for the purpose of adjusting
the brake block relatively to the periphery of the wheel. The free end of the
arm is connected by a link or equivalent to the core of one of the coils so that as
the core is drawn into the solenoid the arm is moved and the brake applied to the
wheel.
Dated this 2nd day of October 1895
H. B. BARLOW & GILLETT,
Agents for Applicant.
Improv
AIC Патре.
I, GEORGE HILL, of the Firm of George Hill and Company, of Trafford
Electric Works, Manchester, in the County of Lancaster, Electrical Engineer, 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 relates to improvements in arc lamps and the object of my
improvements is to govern the movements of the carbons so as to strike and
maintain a uniform arc.
I accomplish this object by an improved form of brake hereinafter described
with reference to the accompanying sheet of drawings in which-
Figs. 1 and 2 are two side elevations of a portion of an arc lamp to which my
improved brake is applied, and
Figs. 3 and 4 are detached views of the brake on an enlarged scale.
In these views,-a a are portions of the frame of the lamp connected by
pillars b, c is a stationary forked bracket, d the shunt coil or solenoid and d the

page_text: series coil, and e e¹ their respective cores fitted and free to be moved vertically in
them. A brake wheel is mounted upon an arbor f' carried in the forked
bracket c and the arm g of my improved brake is pivoted to the bracket c but
eccentrically to the centre of the brake wheel and as near this centre as con-
venient; the other end of the brake arm is connected by a link h to a bracket i
secured adjustably to the core e of the shunt coil d. In the arm g of the brake
is formed near one end, as shown in Figs. 3 and 4, a chamber in which is fitted a
stud with an enlarged end which forms the brake block; on the stem of this stud
is coiled a spiral spring k which is placed in the chamber and the end of the stem
which projects through the back of the chamber is threaded to receive a nut j'
and milled lock nut for the purpose of adjusting the brake block relatively to
the periphery of the brake wheel f. A pinion g' is fixed on the arbor f' and
gears into a spur wheel m carried in the bracket c and in a groove cut upɔn a
flange of the wheel m is placed a chain or cord n the ends of which are secured
respectively to the positive and negative carbon rods o p to which the carbon
holders and the carbons, not shown, are attached.
When the lamp is out of action the core e is in its lowest position in the shunt
coil but as soon as an electric current is passed through the lamp the core e' is
drawn into the series coil d¹ and by a suitable pivoted saddle or connection to
which both cores are pivoted the core e is drawn out of the shunt coil d and the
brake caused to engage immediately with the brake wheelf and carry the same
partly round thereby turning the pinion g' which gearing into the teeth on the
wheel m causes it to turn on its axis and move the chain or cord n which raises
cne and lowers the other carbon rod and so parts the carbons and strikes an arc
between them; the lamp then continues to burn until the carbons waste away and
the arc becomes too long when the shunt coil d gaining strength draws in its
core e to such an extent that the brake is disengaged from the brake wheel fand
so allows the wheel m to turn freely and the carbons to approach one another
until a proper arc is again obtained.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
A brake for an arc lamp consisting of an arm pivoted to a stationary bracket
eccentrically to the brake wheel and with its free end connected in any convenient
manner to the core of a solenoid said arm being chambered to receive an adjust-
able brake block which acts upon the brake wheel all substantially as and for the
purposes herein set forth.
Dated this 2nd day of July 1896.
II. B. BARLOW & GILLETT,
17 St. Ann's Square, Manchester, Agents for Applicant.