Improvements in the Construction of Electrically Controlled Arc Lamps.
Year: 1891

page_text: Date of Application, 2nd Dec., 1891
Complete Specification Left, 2nd Sept., 1892-Accepted. 8th Oct., 1892
Improvements in the Construction of Electrically Controlled
Arc Lamps.
I, FREDERICK THOMAS SCHMIDT, of 44 Bowland Street, Bradford, in the
County of York, Electrician, do hereby declare the nature of this invention to be
as follows:-
The object of this invention is to construct the operating portions of arc lamps
by a novel combination of parts, arranged in such a manner that, the arc or distance
between the carbons is positively formed, and the carbons electrically controlled
and adjusted according to the consumption of the same; and thereby to produce a
steady, regular and uniform light, with a less expenditure of electrical energy by
dispensing with the aid of an electrical shunt or bye pass.
In accomplishing my object, I mount upon a suitable table above the carbons a
solenoid, the plunger or core of which is in connection with two levers placed below
the solenoid and mounted on suitable fulcrums, the opposite end of the levers being
connected by a bar to which is attached a cord that passes over a pulley and to the
other end of the cord is attached a weight.
The before mentioned pulley has a compound groove cut therein, one portion of
the groove being plain, and the other fluted in the direction of the axis, and in
another portion of the pulley, or in a pulley secured to the same axis a milled
groove is cut for the reception of a cord or the like, the ends of which are
respectively attached to the top and bottom carbon holders.
When the full strength of the current is transmitted through the coil of the
solenoid, the core or plunger of the same is lifted to the full height, the cord passing
over pulley with compound groove tightened and a grooved bar brought into
contact with the grooves of the pulley, thus making the connection between the
bar and pulley positive.
As the carbons are consumed, the are becomes longer, therefore the resistance to
the current passing from one carbon to the other is greater, thus reducing the
strength of the current in the solenoid, by which the core or plunger is allowed to
descend and operate the levers in proportion to the influence in the coil, by which
means the cord is raised and the friction of the same in the pulley groove reduced
so that the pulley is readily moved on its axis by the grooved bar, and the carbons
brought towards each other the necessary distance to maintain the arc.
Dated this 1st day of December 1891
JOHN WAUGH,
Agent.
COMPLETE SPECIFICATION.
Improvements in the Construction of Electrically Controlled.
Arc Lamps.
I FREDERICK THOMAS SCHMIDT, of 44 Bowland Street, Bradford, in the
County of York, Electrician, 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 :—
The object of this invention is to construct the operating portions of arc lamps
by a novel combination of parts arranged in such a manner that, the arc or distance
between the carbons is positively formed, and the carbons electrically controlled
and adjusted according to the consumption of the said carbons and thereby, to
Q11

page_text: In rescribing my invention in detail reference is made to the accompanying sheet
of drawings representing so much of an arc lamp as is necessary to make clear my
invention which is added thereto.
Fig. 1. is an elevation of an arc lamp frame fitted with my improvement.
Fig. 2. a view illustrating the opposite side of the same. -
Fig. 3. a plan drawn to a large scale.
Fig. 4. a sectional plan through line a. b.
Fig. 5. a sectional detail of the grooved pulley and the position of the lever
when under electrical control.
Fig. 6. a similar section showing the position of the lever when at rest, and
Fig. 7. a plan of the grooved pulley showing the section of the compound groove
in the same.
Upon a suitable table A. above the carbons B. and C. is mounted a solenoid D.
the plunger or core E of which is prepared with an arm F engaging with the slot
hole cut in lever L. This lever is mounted near its centre on a fulcrum pin J.
and upon the said fulcrum pin is mounted a second lever L the opposite end of
which when the electric current is not passing through the lamp is supported by an
adjustable stop at K. The last named lever may be made to rest on the stop K.
by means of a weight attached to or forming part of the said lever or by its
equivalent a spring S applied in the manner shown.
A cord H. is attached to the lever L. and passes over the pulley P. in the narrow
portion G. of the compound groove, the other end of the cord H. being attached to
the second lever L' so that, when the arc is formed, the cord H. is kept tight in
contact with and grips the pulley P. to such an extent by means of the weighted
lever or by its equivalent spring S. that the pulley P is prevented from
moving on its axis so long as the carbons remain at the requisite distance apart.
The compound groove in the pulley P. is constructed for the reception of two
cords, the one above the other, the narrow groove G. for the cord H. whilst the
enlarged portion of the groove nearer the periphery of the pulley is fluted or
milled at G' in the direction of the axis of the pulley for the twofold purpose,
first for receiving the cord O. supporting the upper and lower carbon holders B'
and C, and secondly in order that the grooved bar Q. attached to the cord H or an
expanded portion of the cord such as a knot, may engage therewith.
The positive and negative wires are attached to terminals secured to the lamp
frame in the ordinary manner, and in any convenient position and when the full
strength of the electric current is transmitted through the coil of the solenoid D.
the plunger or core E. of the same is raised to the full height, thereby operating
the lever L. accordingly and by the cord H. being attached to the opposite end of
lever L. and after passing over the pulley P. in the groove G. is secured to the
lever L by which tension is put upon the cord H. and spring S. by the cord raising
the last named lever.
When the end of lever L' is raised in the manner described, the grooved bar Q.
or an expanded portion of the cord H. engages with the fluted or milled portion G¹
of compound groove, and at the same times moves the pulley P. some distance in
the direction of curved arrow, thereby operating the cord O. resting in the
expanded portion of the compound groove in the same direction, thus moving the
carbons B. and C. apart and thereby forming the arc.
The upper carbon holder B' is heavier than the bottom carbon holder C' and
when electric current is switched off the lamp, the carbons in consequence come
together automatically by gravity, but when the current is switched on, the carbons
are separated a distance in proportion to the strength of the electric current or
electro magnetic influence in the coil of the solenoid, so that as the carbons B and C.
are consumed, the are or space between the two carbons becomes longer, therefore
the resistance to the electric current passing from one carbon to the other becomes
greater, thereby reducing the strength of the current in the solenoid D. thus

page_text: allowing the plunger or core E. to descend and operate the levers L and L' in a
downward direction, a distance in proportion to the reduced magnetic influence in
the coil of the solenoid D.
When the strength of the current or electro magnetic influence in the solenoid D.
is reduced so as to allow the lever L' to rest upon the adjustable stop K. the tension
and therefore the grip of the cord H in the groove G. is reduced so that the
positive engagement of the grooved bar Q. with the flutes at G¹ is withdrawn,
thus liberating the pulley P to such an extent that by the top carbon holder and
carbon B. being heavier than the bottom carbon holder and carbon C. they are
allowed to approach each other, and by the reduction and adjustment of the distance
between the carbons to thus maintain the arc.
By the reduction in the distance between the carbons in the manner described
the electro magnetic influence in the solenoid is again increased, causing the
plunger or core E. to rise and again operate the levers L and L. in the manner as
before described such a distance that the tension of the cord H. is increased, thus
gripping the pulley P. and causing the grooved bar Q. or its equivalent on the
cord H. to engage with the fluted or milled portion G by which means the arc or
distance between the carbons is being continually adjusted and a steady and
regular light maintained.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I.declare that what I
claim is
1. In an arc lamp the use of a pulley having a compound groove for the purpose
of receiving from a solenoid through which the entire lighting current passes, the
energy employed in separating the carbons and controlling their relative positions
during combination, substantially as hereinbefore described and shown.
2. The hereinbefore described method of operating the carbons of an arc lamp
by means of the current employed to light the lamp, the said method comprising
(a) the separation of the carbons against the force of gravity by means of the
action of a grooved rod or its equivalent upon the milled groove of a pulley and
() the control of the movement of the carbons in approach to one another under
the action of gravity by means of the friction of a thread or other flexible band
upon a smooth surface in the groove of the same pulley.
3. In an arc lamp the use of a pulley P. having a compound groove in
combination with the grooved bar Q. as herein before described and shown.
4. The arc lamp hereinbefore described and shown in the accompanying drawings.
Dated this 1st day of September 1892.
JOHN WAUGH,
Agent.