Year: 1887

page_text: Date of Application, 17th May, 1887
Complete Left, 17th Jan., 1888
Complete Accepted, 6th Apr., 1888
1, WILLIAM MACKIE of Turks Head Yard, Turnmill Street in the County of
Middlesex Electrical Engineer do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to produce an electric arc lamp having all the quali-
fications of a differential arc lamp but the feed being governed by the action of the
shunt coil leaving the influence of the main coil inactive or nearly so.
To accomplish this I construct the lamp so that the main coil is not a fixture but is
free to move in such a position that it shall be capable of striking an arc & then
affixing itself on to the core of the shunt solenoid. The action of the shunt solenoid
core will then be to return the main coil to its original feeding position.
Our way of doing this is to suspend the main solenoid coil upon one end of a
balance beam & to weight the opposite end so as to overbalance the main coil & thus
liberating the arc striking gear.
This solenoid coil having an iron button fixed in one end is suspended over its own
core to a sufficient distance to enable it on its coming down to strike the necessary
length of arc. This main solenoid core is attached to the core of the shunt solenoid,
having a dash-pot between the two, the total weight of these cores & dashpot being
greater than that necessary to strike the are they will remain stationary until the
shunt coil becomes of sufficient strength to lift them which it will continue to do until
it has returned the main coil to its feeding position.
If it overfeeds the system of cores will fall & open out the arc again.
Or my
invention may
be accomplished by fixing the main solenoid coil & having
two iron cores one of which actuates the striking gear, the other being attached by a
non-magnetic distance piece to the shunt solenoid core.
These main cores are fitted so that there shall be a space between them at starting
& that the amount of iron protruding out of each end shall be equal or nearly so.
The action of the current passing through the main coil will then tend to draw both
cores into it & the core striking the arc will then attach itself on to the other core.

page_text: Now as there would then be an equal amount of iron through each end of the coil
very little power would be required to move these combined cores up & down for some
distance. The shunt coil would then control this system of cores & regulate the feed
without the influence of the main coil having an appreciable influence on it.
Sometimes I use a brake for the purpose of striking the arc & controlling the feed
of the carbons, & I form this brake by means of a shoe which is pressed against the
periphery of a wheel attached to the shaft of a pinion. This shoe is actuated by a
lever through which the shaft of the pinion passes. The shoe is pivoted upon this
lever in such a way that it tends to keep a perpendicular position; when therefore the
lever is lifted up the shoe is caused to grip the wheel & upon the lever descending the
shoe comes against a stop which forces it off the wheel.
Dated this Sixteenth day of May 1887.

page_text: I WILLIAM MACKIE Turks Head Yard Turnmill Street in the County of Middlesex,
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:-
The object of my invention is to produce an electric are lamp having all the quali-
fications of a differential arc lamp but the feed being governed by the action of the
shunt coil having the influence of the main coil inactive or nearly so.
To accomplish this I construct the lamp so that the main coil is not a fixture but is
free to move in such a position that it shall be capable of striking an arc & then
affixing itself on to the core of the shunt solenoid. The action of the shunt solenoid
core will then be to return the main coil to its original feeding position.
One way of doing this as shown in Figure one is to suspend the main solenoid coil
upon one end of a balance beam & to weight the opposite end so as to overbalance the
main coil & thus liberating the arc striking gear.
This solenoid coil having an iron button fixed in one end is suspended over its own
core to a sufficient distance to enable it on its coming down to strike the necessary
length of arc. This main solenoid core is attached to the core of the shunt solenoid &
having a dash pot between the two, the total weight of these cores & dashpot being
greater than that necessary to strike the arc they will remain stationary until the
shunt coil becomes of sufficient strength to lift them which it will continue to do
until it has returned the main coil to its feeding position or the main coil can be placed
on the other end of the beam as shewn in Fig. 2.
If it overfeeds the system of cores will fall & open out the are again. Or
my invention may be accomplished by fixing the main solenoid coil & having two
iron cores one of which actuates the striking gear the other being attached by a
non magnetic distance piece to the shunt solenoid core.
These main cores are fitted so that there shall be a space between them at
starting & that the amount of iron protruding out of each end shall be equal or
nearly so.
The action of the current passing through the main coil will then tend to draw
both cores into it & the core striking the arc will then attach itself on to the
other core.
Now as there would then be an equal amount of iron through each
end of the coil very little power would be required to move these combined cores
up & down for some distance. The shunt coil would then control this system of
cores & regulate the feed without the influence of the main coil having any
appreciable influence on it.
Sometimes I use a brake for the purpose of striking the arc & controlling the
feed of the carbons & 1 form this brake by means of a shoe which is pressed against
the periphery of a wheel attached to the shaft of pinion. The shoe is actuated by a
lever through which the shaft of the pinion passes. The shoe is pivoted upon this lever

page_text: in such a way that it tends to keep a perpendicular position, when therefore the
lever is lifted up the shoe is caused to grip the wheel & upon the lever descending
the shoe comes against a stop which forces it off the wheel."
Or the application of the shoe may be reversed & the lever would then tend to keep
a perpendicular position as shewn in Figure 3.
DESCRIPTION OF DRAWINGS.
Figure 1 arc lamp. A main coil B balance beam C main solenoid core D iron
button E connecting link between main core C & shunt core F, G shunt coil, H dash
pot, I weight J lever actuating brake K on wheel L, stop O.
Figure 2 arc lamp main coil A, balance beam B, main core C, Iron button D, dash
pot E, break lever H, brake shoe I, break wheel J, stop L, shunt coil M, shunt core O,
weight P.
Figure 3 shoe H; Lever I brake wheel J stop O.
Having now particularly described & ascertained the nature of my said invention &
what manner the same is to be performed I declare that what I claim is
1st. I claim the application of a moveable main coil as a connecting link between
the feeding gear & the regulating gear of the lamp.
2nd. I claim the regulation of the feeding of an are lamp by means of a shunt
coil which coil may be partially retarded from feeding by the action of the main
coil.
3rd. I claim the construction of a brake all substantially as described.
4th. I claim the construction of an are lamp substantially as described.
Dated this Seventeenth day of January eighteen hundred & eighty-eight.