IMPROVEMENTS IN ELECTRIC ARC LAMPS AND MECHANISM FOR ELECTRIC LIGHTING
Year: 1882

page_text: LETTERS PATENT to James Kenneth Douglas Mackenzie of Halifax in the
County of York Electrical Engineer for an Invention of "IMPROVEMENTS
IN ELECTRIC ARC LAMPS AND MECHANISM FOR ELECTRIC LIGHTING
"
PROVISIONAL SPECIFICATION left by the said James Kenneth Douglas
Mackenzie at the Office of the Commissioners of Patents on the 23rd August
1882.
JAMES KENNETH DOUGLAS MACKENZIE of Halifax in the County of York
Electrical Engineer "IMPROVEMENTS IN ELECTRIC ARC LAMPS AND MECHANISM
FOR ELECTRIC LIGHTING"
My Invention has for its object to provide a contrivance for regulating the
distance between the points of the carbons of arc lamps which contrivance is
extremely simple and inexpensive and at the same time secures steadiness of
light.
Arc lamps and incandescent lamps can also be used at the same time on the
same circuit and either of such lamps can be lighted extinguished substituted
or changed while the current is on without disturbing the other lights on the
circuit.
The action of the mechanism causing the self adjustment of the carbon points
in anyone lamp on a circuit in noway affects the light of any other lamp
whether arc or incandescent on the circuit and the self adjustinent is rapid and
certain.
According to my Invention the upper carbon is attached to a brass rod which
is placed between two electro magnets whose coils are in the lamp circuit The
said rod passes through jaws carried by the armature of such magnets and is
by them sustained The armature consists of two pieces of metal forming each
a half of the armature and each having a projecting boss which between them
form the jaws for grasping the carbon holder.
These two parts of the armature are connected by two flat pieces of steel which
serve as a binge-The inner faces of the jaws are preferably bevelled off so as
CD..

page_text: to allow greater play at the top than the bottom. On each half of the armature
is a brass loop in which the ends of springs rest-These springs are made of flat
steel and are screwed or rivetted at their other ends to a fixed base plate so that
the said springs tend to hold down the centre of the armature upon supports or
pillars also carried by the base plate and while the armature is in this position
the carbon holder can work freely up and down-The said springs are sufficiently
strong to counteract the force of the magnets when the carbons are too far apart.
There are two flat circular discs one rivetted at one side to the top of each half
of the armature the other side of each disc being raised to touch the pole pieces
of the electro magnets in order to prevent the armature from sticking to the
electro magnets and also to help to convey the current to the carbon holder-
The armature is supported at its extremities by two cross pieces which are
sustained by nuts working on rods carried by the before mentioned base plate.
A metallic comb conveys the current to the carbon holder. The mechanism is
or may be enclosed in a metal case The current enters at one of the hooks or
terminals and travels round the core of each magnetic coil simultaneously-The
ends of these coils are soldered to the bobbin containing them. Leaving the
bobbin the current enters the metal case and from thence passes into the carbon
holder The before mentioned metallic comb insures the current passing into the
carbon holder-This makes the positive pole of the arc from thence it passes into
the frame work of the lamp and so out by the other hook or terminal-Two or
more sets of carbons may be arranged in a lamp so as to act either together or in
succession the one after the other.
The following is the action.
The carbons are placed in position and the current turned on and each half
of the armature is drawn to the magnets and the carbon holder is sustained in its
place by the jaws of the armature,
Directly the carbon wears away the magnetic current is lessened and the
springs drawing each piece of the armature down the rod is released and the
carbon is lowered and the instant the carbon lowers the arc is formed between
it and the other carbon whereby the magnetic current is again set up and the
parts of the armature rise and the carbon holder is supported in its place until
a similar process is repeated.
I employ regulating cells for the arc light alone or for the are and incandescent
lights combined-These cells are of lead and are grouped together in a box in any
suitable number say for example twelve-One of such groups is connected in
shunt or derivation to each lamp the object being to allow free transmission of
the current to the other lamps whether arc or incandescent on the circuit during
the momentary stoppage of any one lamp through the self adjustment of its
carbon or while making any change in the lamps e.g. changing a lamp or sub-
stituting an arc for an incandescent or vice versa-The regulating cells also allow
incandescent lamps to burn steadily.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Kenneth Douglas Mackenzie in the Great Seal Patent
Office on the 23rd February 1883.
JAMES KENNETH DOUGLAS MACKENZIE of Halifax in the County of York
Electrical Engineer "IMPROVEMENTS IN ELECTRIC ARC LAMPS AND MECHANISM
FOR ELECTRIC LIGHTING"
The Invention has for its principal object to provide a contrivance for regulating
the distance between the points of the carbons of Arc lamps which contrivance
is simple and inexpensive and at the same time secures steadiness of light.
Arc lamps and incandescent lamps can also be used at the same time on the
same circuit and either of such lamps can be lighted extinguished substituted
or exchanged while the current is passing without disturbing the other lights on
the same circuit.
The action of the mechanism causing the self adjustment of the carbon points
in any one Arc lamp on a circuit in no way affects the light of any other lamp
whether Arc or Incandescent and the self adjustment of the carbon points in each
Arc Lamp is rapid and certain.
According to my Invention the upper carbon in an Electric Arc Lamp is attached
to a brass rod constituting the carbon holder which rod is placed between two
electro magnets whose coils are either in the main current or in derivation as a
shunt therefrom
The said rod passes through jaws carried by the armature of such magnets and
is by them sustained The said armature consists of two pieces of metal forming
each a half of the armature and each piece having a projecting boss which
between them form the jaws for grasping the before mentioned brass rod or
carbon holder.
The two parts of the armature are connected on the lower side without touching
each other by two pieces of thin flat steel one on each side of the projecting boss
and serving as a hinge. The inner faces of the jaws are preferably bevelled off so
as to allow greater play at the top than the bottom.
On each half of the armature at the boss end and on the under side is a brass
loop and in each loop the end of a spring rests. These springs are made of flat
steel and are screwed or rivetted at their other ends to a fixed base plate so that
the said springs tend to hold down the boss ends of the armature. While so held
down the armature rests upon supports or pillars also carried by the base plate
and perpendicular thereto While the armature is in this position the brass rod
or carbon holder can work freely up and down The said springs are made of
sufficient strength to counteract the force of the electro magnets when their power
is lessened by the points of the carbons being too far apart.
In order to prevent the armature from sticking to the electro magnets and also
to help to convey the current to the carbon holder two flat circular discs are
employed A disc is rivetted on one side of its edge to the top of each half of the
armature the other side of each disc being raised to touch the pole pieces of the
electro magnets The armature is supported at its extremities by two cross pieces
of metal which are sustained by metal nuts working on the before mentioned
supports or pillars and carried by the before mentioned base plate. A metal comb
can convey the electric current to the carbon holder.
The before mentioned mechanism is enclosed in a metal case to the upper part
of which the electro magnets are attached. Two hooks or terminals are fixed above
the case one being in metallic contact with the same the other insulated and con-
nected with the framework of the lamp other than the case. The electric current

page_text: enters at the hook or terminal which is metallically connected with the case and
travels round the core of each magnetic coil either directly as a whole or partially
as a shunt. The ends of these coils may be soldered to the bobbins containing
them.
The current enters the metallic case of the mechanism and passes into the carbon
holder either from the bobbins or directly from the hook or terminal. The before
mentioned metallic comb ensures the current passing into the carbon holder This
makes the upper carbon the positive pole of the arc. From thence the current
passes into the lower carbon or negative pole and thence into the metallic frame-
work of the lamp and so out by the other hook or terminal This describes a
single lamp with two carbons only but two or more sets of carbon may be arranged
in a lamp so as to act simultaneously or in succession the mechanism being
arranged accordingly and upon the same principal substantially as herein before
described.
And in Order that my said Invention may be properly understood I shall now
proceed to describe the system mode or manner in or under which the same may
be performed reference being had to the accompanying drawings and to the figures
and letters marked thereon like letters being used to denote the same parts in all
the Figures.
Figures 1 and 2 represent in front and side elevations respectively a lamp
provided with my present improvements.
Figures 3 and 4 are front and end elevations of the regulating mechanism.
Figure 5 represents the top or upper side of the armature of the regulating
mechanism and Figures 6. 7 and 8 are respectively a longitudinal section an end
view and a plan of underside of the said armature. The said armature consists of
two pieces of metal A A each piece having projections B B at one end forming a
boss. The said pieces A. A are connected together on the lower side (but so that
the faces of the bosses do not touch) by two pieces of thin flat steel C C which
serve as a hinge This is shewn clearly in Figure 8. In the centre of the boss B B
is a hole of the diameter of the carbon holder. The inner faces of the boss are
bevelled off (as shewn in Figure 6) so as to allow greater play at the top than at
the bottom JJ are two flat circular discs one side being rivetted to the top of
the parts of the armature on the end furthest from the centre The other side of
each disc is raised or bent up above the surface of the armature sufficiently to touch
the poles of the electro magnets when the jaws of the armature do not grasp the
carbon holder D D indicate the two loops or stirrups made of flat or round brass
the ends whereof are fastened to some part of the armature preferably the edges so
as to form a loop to each piece of the armature as is clearly shown in Figure 7
Figure 9 shews the arrangement of the armature with the base plate. E E are the
springs one end of each of which passes through but is not fastened to the loops or
stirrups D D the other end being rivetted to the base plate F These springs tend
to hold down the centre of the armature upon the four supports or pillars G G (of
which two only are seen in Figure 9) and while the armature is in this position
the carbon holder H can work freely up and down in the jaws of the armature.
The springs E E are sufficiently strong to counteract the magnets when their force
is lessened by the carbons being too far apart. In figure 3, M is a metal comb
rivetted to the case and bearing on the carbon holder H thereby insuring the
electric current being conveyed to the said carbon holder. N. N. are the electro
magnets. The outer ends of the divided armature are supported upon washers LL
(or other equivalent device) which rest upon nuts the the height of which can be
adjusted by screwing them up or down the supports or pillars K K which are
provided with a screw thread for that purpose.
The said supports or pillars, K K, and the supports or pillars, G G, are screwed
into the base plate for the purpose of regulating the tension of the springs and the
action of the jaws of the armature. The form of the lamp may be modified as
required. The following is the action of the said apparatus. The carbons are
placed in position touching one another and the current is turned on whereby each

page_text: part, A A, of the armature is drawn to the magnets and the upper carbon holder
rod H is raised and sustained in its place by the jaws, B B, of the armature. As
the carbons wear away the power of the electro magnets is weakened and the
springs, EE, and J, J, then draw each piece of the armature down.
The upper
carbon rod H is thus released from the grip of the jaws B B and falls, thus
shortening the length of the arc and in so doing increasing the power of the electro
magnets, N N, until they are again able to raise the armature and with it the upper
carbon rod, thus reforming the arc.
This process is instantaneous and is repeated each time the carbons are sufficiently
consumed.
I may employ regulating cells for the arc light alone or for the incandescent
lights alone or conjointly with my improved arc lamp. The regulating cells are
of lead filled with fluid and are grouped together in a box in any suitable
number.
One of these groups is connected in shunt or derivation to each are lamp or group
of Incandescent lamps, the object being to allow free transmission of the current
to the other lamps on the circuit whether arc or incandescent during a momentary
or temporary stoppage of any one lamp through the self adjustinent of its carbon or
while inaking any change in the lamps such as in renewing a carbon or changing a
lamp or substituting an arc lamp for an incandescent lamp or vice versa.
The regulating cells also allow incandescent lamps on a circuit to burn steadily
and independently of each other.
To prevent any current running back to the Dynamo from the regulating
batteries after the engine or motor is stopped a cut out may be used to each
battery and such cut out may be automatic.
Having now described and particularly ascertained the nature of my said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that I do not claim as original the before
mentioned regulating cells nor do I clain the running of arc and incandescent
lamps on the same circuit but what I consider to be novel and original and therefore
claim as the Invention secured to me by the hereinbefore in part recited Letters
Patent is:
First. The general arrangement or combination of parts constituting the regu-
lating mechanism of the Electric lamp substantially as hereinbefore described and
illustrated in the accompanying drawings.
Secondly. The split armature and counteracting springs for alternately grasping
and releasing the carbon holder and automatically lifting the upper carbon sub-
stantially as and for the purpose herein before described and illustrated in the
accompanying Drawings.
Thirdly. The use of regulating cells substantially in the manner herein before
described on a circuit either of arc lamps alone or Incandescent lamps alone or
both together by which means the electric current is transmitted, without its
strength being materially altered to the lamps on the same circuit during the
momentary stoppage of any one lamp either through the self adjustment of the
carbons in an arc lamp or the failure of an incandescent lamp or any temporary
stoppage while making any change in the lamps on the circuit.
In witness whereof I the said James Kenneth Douglas Mackenzie have to
this my Specification set my hand and Seal this Twentythird day of
January One thousand eight hundred and eighty three.
AMES. KENNETH, DOUGLAS. MACKENZIE. (L.S.)