Improved Mechanism for Electric Arc Lamps.
Year: 1896

page_text: Date of Application, 21st Sept., 1896-Accepted, 7th Nov., 1896
COMPLETE SPECIFICATION.
Improved Mechanism for Electric Arc Lamps.
We, P. R. JACKSON AND COMPANY, LIMITED of Salford Rolling Mills, Manchester,
Engineers, and LOUIS CARL HENRY MENSING, of 89 Worship Street, London,
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:-
This invention relates more particularly to that class of arc lamp in which the
carbons are fed together by gravity under the control of a band or other kind of
brake actuated by a solenoid or electro-magnet connected as a shunt across the arc.
The invention will be clearly understood upon reference to the accompanying
sheet of drawings in which
Figure 1 is a side elevation of a lamp with mechanism constructed in accordance
with the invention.
Figure 2 is a side elevation of part of the lamp frame to more particularly show
the construction of the suspension cord and brake wheels and the manner of
suspending the same.
Figure 3 is a plan of what is hereinafter termed the pendulum, and
Figure 4 is a cross section on the line 1, 1, of Figure 1 showing the method of
arranging the bottom carbon carrier on and within the guide post.
Figure 5 is a side elevation of an alternative form of lamp mechanism embodying
the same mechanical and electrical principles.
Figure 6 is a reverse side elevation of the lamp mechanism.
Figure 7 is a top plan of the grooved wheel and carrier and mechanism for
regulating the brake band.
Figure 8 is an under plan of the wheel carrier and brake lever.
Referring to Figure 1, we mount upon the base plate A the frame or standards B, B,
between which is suspended from projecting lugs C the pendulum D and grooved:
wheel E, and to the lugs F, F, a cradle G is pivoted in any convenient manner.
The pendulum Dis formed preferably in a piece with the arms H, H, that project
backwardly from the bosses I, I, and terminate in a fork J that embraces the top
end K of the core L within the solenoid M and the lower end of the pendulum D is
formed with guide slot N through which the metallic cord P passes from the groove a
of the grooved wheel E for attachment to the top carbon carrier Q, it being guided
and maintained in its central position by the pulley R.
The lower carbon carrier S is formed on one side with a ferrule T that encircles
the guide U in which a slot V is cut for the insertion of a feather W formed in a
piece with the ferrule T and a rod X within the guide U. The end of the rod X.
is formed with an eye for the attachment of a silk or other flexible cord Y.
which after passing over a guide pulley Z is attached to the grooved wheel E in the
groove b.
The brake wire c is attached on one side by a coupler d to the horn e forming
part of the lever f pivoted at the point 9 to a lug attached to the bottom of the
pendulum D and after being laid in the groove of the wheel E is attached to a
screw having flat sides and fitting a hole k of corresponding shape in the pro-..
jection to prevent same from turning when adjusted and locked by the.
nuts m, m.

page_text: The lever is connected to the cradle G and carries a weight n it being found
in practice that this position of the weight n imparts a livelier and more sensitive
or elastic action to the mechanism than if for instance it was placed on the lower
end of the pendulum, moreover less weight is required to counterbalance the weight
of the pendulum D.
The part L of the solenoid core is composed of magnetic material (while
the upper part K is of non magnetic material such as brass) and in the figure
it is at its lowest position and the brake wire e tightly gripping the wheel E, the
carbons being drawn apart.
In order that the pendulum D and grooved wheel E may be suspended in as
simple and delicate a manner as possible, the screw p is screwed into the lugs C, C,
and upon the reduced diameter q, the pendulum D is hung by the bosses I, I,
while the smallest diameter q' is inserted into the hole r of the hub s of the
wheel E.
In this lamp, each of the carbon carrier cords P, Y, are secured in their
respective grooves a, b, by being passed through a hole and a knot made behind it, and
the top carrier Q is slightly heavier in order that the tendency of the carbons is to
come tegether whenever the brake wire c is released. The wheel E is weighted at E'
so that as the carbons burn away it automatically exerts an increasing leverage and
tends to maintain a constant potential at the arc.
The action of the lamp is as follows:-
The solenoid being connected as a shunt across the arc and the carbons at starting
being at about are distance it follows when the lamp is put in circuit that the
solenoid is energised owing to the resistance to the passage of the current across the
are with the result that the core L is drawn into the solenoid from below and by
swinging the pendulum inwards and the arms H upwards it causes the wheel E by
reason of the bight of the wire c upon it to move with it and thereby raise the
bottom carbon carrier and lower the top carrier sufficiently for the carbons to kiss,
thus momentarily de-energising the solenoid and allowing its core to overbalance the
pendulum and weighted lover and turn the wheel back sufficient to separate the
carbons and strike the arc, if the carbons are too far apart at starting, the core L is
lifted until the wire is slack upon the wheel E and allows same to turn until the
carbons meet, the levers G and being pivoted in the manner shown causes the cord
to tighten upon the wheel E when the arc resistance decreases, and loosen when the
are resistance increases thereby allowing the carbons to feed together or separating
them as the case may be all under the control of the solenoid M.
In order that the brake wire may be released a small push button t is provided in
the pocket u which when pushed will allow the carbon carriers to be slid apart
such as for instance when it is required to insert new carbons.
The form of lamp illustrated in Figures 5, 6, 7 and 8 is intended for use with
small currents and can be made of very small size for use in dwelling rooms and
other places of comparatively small dimensions.
The equivalent of the pendulum D is in this case preferably arranged horizontally
and in the form of an oscillating frame surrounding the grooved wheel E mounted
between it, the whole being pivoted to the standard B by the screw p in such a
manner that the cords P, Y, descend straightly to the upper and lower carbon
carriers respectively.
Inasmuch that the whole of the mechanism is arranged as closely as possible to
the grooved wheel E, the arm j to which one end of the brake wire c is attached is
pivoted to the same centre as the wheel E and is recessed into the frame D as
indicated in Figure 2, so that when lifted to adjust the tension of the brake wire cit
partakes of a radial movement thereby allowing the tension of the brake to be
adjusted within comparatively wide limits without unduly lessening or increasing the
circumferential grip of the wire. The position of the arm j is adjusted and fixed by
the clamp screw m in the slot mi².
The brake lever is also recessed into the frame D but on the under side thereof
and is pivoted to said frame at the point g, this being the fulcrum for transferring

page_text: the leverage of the lever to the horn e and coupler d having attached to it, the other
end of the brake wire c. The opposite end of the lever is pivoted to the cradle G
in the same manner as described with reference to Figure 1. The forked end J of
the arm H embraces the core K and when in action is drawn down into said solenoid
when energised by a current flowing through the coil owing to the resistance to the
passage of the current across the arc.
When the arm H is drawn down, the opposite end of the frame D rises taking with
it the fulcrummed end of the lever f which is thereby caused to assume a more
parallel position relatively thereto and thus to slacken out the brake wire and release
the wheel E allowing the carbons to feed together and momentarily kiss before being
drawn apart to strike the arc by the return movement of the frame D under
the action of the counterbalance D'. When the solenoid coil is de-energised by the-
decreased are resistance, the subsequent feeding together of the carbons, and the
maintenance of a practically constant potential at the are being effected in the same
manner as previously described.
If necessary, the mechanism of this lamp can be reversed or be so arranged that
the core K may project below the base of the lamp and be drawn upwards by the
solenoid in the manner shown in Figure 1 without departing in any way from the
principle of construction involved.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. In an electric arc lamp, the combination with a pendulum or oscillating
frame D having backwardly projecting arm or arms H, H, and fork J embracing a
solenoid core of a weighted wheel E having grooves a, b, and i for the reception of
the top and bottom carbon carrier cords P, Y, and brake wire c respectively, and
suspending the pendulum or oscillating frame D and wheel E between the
standards B, B, and lugs C, C, by screws p having diameters q, g', as described
and shown.
2. In an electric are lamp, the combination with the parts set out in Claim 1 of a.
lever connected by a coupler d to one end of the brake wire e and fulcruming said
lever to a lug h on the pendulum or oscillating frame D, so arranged as to carry a
flat sided screw or adjustable lever j to which the other end of the brake wire c is
attached and adjustable as to tension or grip upon the wheel E by the nuts m, m³,
and articulating said lever f to a cradle G pivoted to the lugs F, F, between the-
standards B, B, the lever in the case of Figure 1 being so weighted by a weight n
outside the fulcrum 9 to act as a counterbalance to the weight of the pendulum, as
described and shown.
3. In an electric arc lamp, the combination with the parts set out in Claims 1 and 2
of a solenoid M connected as a shunt across the arc and arranging the core Lof
magnetic material in combination with the part K of non-magnetic material in such
a manner that the core L projects below the solenoid M, and is drawn upwards-
under the action of a passing current in said solenoid for effecting and controlling the
various functional operations, substantially as described and as shown with reference
to Figure 1.
4. The arrangement of a push button t in the pocket u for releasing the grip of
the brake wire upon the wheel E for the purpose described.
5. In an electric are lamp, the combination with the parts set out in Claims 1
and 2 of a solenoid M connected as a shunt across the arc and arranging said
solenoid in relation to the oscillating frame that the core K and the end of the
oscillating frame attached thereto is drawn downwards under the action of the
current for effecting and controlling the various functional operations as described
with reference to Figure 5.
6. In an electric are lamp, the combination with a frame D of a radially
adjustable arm j pivoted to the same centre as the wheel E, and a brake lever f

page_text: fulcrummed to said frame D and connected to a cradle G all arranged and
operated in the mannner described with reference to Figures 5 to 8 inclusive.
Dated this 21st day of September 1896.
H. GARDNER,
Patent Agent, 166 Fleet Street, London,
Agent for the said P. R. Jackson and Company, Limited, and
Louis Carl Henry Mensing.