IMPROVEMENTS IN MECHANISM FOR REGULATING ELECTRIC ARC LAMPS
Year: 1884

page_text: I THOMAS CUTTRISS Electrical Engineer 72 New Briggate Leeds Yorkshire do
hereby declare the nature of my invention for IMPROVEMENTS IN MECHANISM FOR
REGULATING ELECTRIC ARC LAMPS, to be as follows:-
The top carbon is fixed to a rack which is free to move up or down through
supports at the top and bottom of the lamp, into the rack is geared a pinion which
is supported on a lever at a suitable distance from its fulcrum so that when tho
lever is raised or lowered the pinion describes an are & in doing so raises or lowers
the rack accordingley the pinion at the same time being kept from revolving until
the proper time by suitable mechanisın.
Fixed to the pinion is a ratchet wheel for the purpose of allowing the rack to be
raised to permit of the replacing of the carbons without bringing the remaining
mechanism into play, upon allowing the rack to decend a catch engages with the
ratchet wheel & causes the decent of the carbon to be controlled by means of the
mechanism hereinafter described.
Upon the same shaft as the ratchet wheel and pinion, is a spur-wheel to the side
of which the ratchet is fixed, the spur-wheel engages in a pinion which rotates
upon a suitable support fixed to the lever at a greater distance from its fulcrum
than that of the rack pinion. Fixed to the pinion & revolving with it is an
escapement wheel and into the escapement wheel works a pallett or palletts for the
purpose of preventing the too rapid decent of the carbon upon the lever in a
suitable manner is fixed a catch which engages in the escapement wheel for the
purpose of locking the mechanism in the following manner.
Fixed to the frame of the lamp is a projection upon which the catch rests when
the lever is below a certain position, when the lever rises above that position the
catch rising with it is lifted off the projecting piece and is free to fall between the
teeth of the ratchet wheel and so keep it from revolving, but when the lever fulls
below that position the catch resting upon the projection is released from the
escapement wheel and the wheels are free to revolve and the carbon to fall.
Attached to the lever for the purpose of lifting it is the plunger of a solenoid
or solenoids, the solenoid or solenoids being wound with thick insulated wire and
form part of the main electrical circuit of the lamp-together with a shunt coil of
high resistance between the terminals of the lamp acting upon the thick wiro
solenoids but in the opposite direction to the main circuit in that way tending to
neutralise the magnetisin produced by the thick wire coils.

page_text: The action of the mechanism is as follows, on a current from any source of
electricity passing round the solonoids they are magnetised and drawing in tho
plunger lifts up the lever and the top carbon rising with it the arc is formed, the
catch rising with the lever is free to engage with the escapement wheel and prevent
the decent of the carbon until by the, gradual lengthening of the arc by the
consumption of the carbons and thereby increase of resistance in the main circuit
a greater portion of the current passes through the shunt coils which acting in-
opposition to the thick wire coils allows the plunger to decend and with it the lever
until the catch by resting on the projecting piece liberates the mechanism and
allows the carbon to decend, the resistance of the arc now being reduced the
current in the shunt coils returns to its normal strength and the plunger is again
lifted, the same action being repeated time after time until the carbons are
consumed.
Having now described my invention I would have it understood that I do not
confine my self to exact details as they can be varied in many ways without
departing from the particular features of my invention.

page_text: DELICATION.
I, THOMAS CUTTRISS Electrical Engineer 72 New Briggate Leeds in the County
of York do hereby declare the nature of my invention for IMPROVEMENTS IN
MECHANISM FOR REGULATING ELECTRIC ARC LAMPS and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :-
The top carbon is fixed to a rack A, fig I and II, which is free to move up or
down through supports at the top and bottom of the lamp. Into the rack is
geared a pinion B, which is supported on a lever C, at a suitable distance from its
fulcrum D, so that when the lever is raised or lowered, the pinion B describes an
arc, and in doing so raises or lowers the rack, the pinion at the same time being
kept from revolving until the proper time by suitable mechanism.
I will now describe one arrangement by which the decent of the rack may be
regulated.
Fixed to the pinion B, and rotating with it is a ratchet wheel E, for the purpose
of allowing the rack to be raised to permit of the replacing of the carbons without
bringing the remaining mechanism into play.-Upon allowing the rack to decend,
a catch F engages with the ratchet wheel, and causes the decent of the rack to be
controlled by means of the mechanism herinafter described.
Upon the same shaft as the ratchet wheel and pinion, is a spur wheel G, to the
side of which the ratchet is fixed-the spur wheel engages in a pinion H, which
rotates upon a support fixed in the lever; attached to this pinion and revolving
with it is an escapement wheel I, and into the escapement wheel works a pallett J
for the purpose of preventing the too rapid decent of the rack. Attached to the
lever in a suitable position is a catch K, for the purpose of locking the mechanism
when required in the following manner.
Fixed to the frame of the lamp is a projection L upon which the catch rests
when the lever is below a certain position, when the lever rises above that position
the catch rising with it is lifted off the projecting pieco and is free to fall between
the teeth of the escapement wheel and so keep it from revolving, but when the
lever falls below that position the catch resting upon the projection is released
from the escapement wheel, and the wheels are free to move & the rack to fall.
Attached to the lever for the purpose of moving it is the plunger M, of a sole-
noid N, wound with insulated wire or wires and connected up electrically in the
usual way employed for arc Lamps.
Fig 3 shews a somewhat different arrangement of my invention which in some
cases I use in preference to the one shewn in figs I and II. I have left out the
details of the train of wheels for the sake of clearness in the illustration.
A fig III is a lever. supported in a suitable manner at its fulcrum B, at one end
is the rack pinion C, and at the other the plunger D of a solenoid E-on reference
to the drawing it will be seen that the action of the regulating mechanism is
similar in both cases, and will need no further description the principal difference
between the arrangement as shewn in Fig I and the arrangement shewn in Fig 1II

page_text: being that in Fig I tho fulcrum of the lever is at one end, and the solenoid plunger
at the other; in Fig III the fulcrum is between the rack pinion and the solenoid
plunger, by that means the weight of the rack and carbon is to a great extent
balanced by the weight of the long end of the lever and the solenoid plunger, thus
producing a more steady action of the lamp.
I would have it understood that I do not confine myself to exact details as
shewn in the drawings, as they may be varied in many ways without departing
from the particular features of my invention.
I am aware that are lamps have been constructed with an escapement wheel and
pallett for regulating the decent of the carbon, & to that part of the mechanism
I lay no claim.
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
I. A lever carrying a rack pinion and suitable regulating mechanism, and
oscillating on a fulcrum at a suitable distance from the centre of the pinion which
gears into the rack carrying the upper carbon; the whole being actuated by a
solenoid plunger attached to the end of the lever substantially as shewn in Figs I
and II.
II. A lever carrying a rack pinion and suitable regulating mechanism, and
oscillating on its fulcrum at a suitable distance from the centre of the pinion which
gears into the rack carrying the upper carbon; the whole being actuated by a
solenoid plunger attached to the lover at a point on the opposite side of the fulcrum
of the lever to that of the rack pinion, substantially as shewn in Fig III.
III. The regulation of the upper carbon in an arc lamp by means of a pinion
gearing into the rack carrying the upper carbon, the pinion being attached to a
lever in such a manner as to describe an arc when the lever is moved on its
fulcrum, and while so doing actuating the rack, the revolution of the pinion
being at the same time controlled by suitable mechanism substantially as shewn in
figs I II and ILL
Dated his 10th ... f 100