Improvements in Electric Arc Lamps, specially applicable for Lantern Purposes.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps, specially applicable for
Lantern Purposes.
I FREDERICK WOODWARD BRANSON of 14 Commercial Street Leeds in the
County of York Pharmaceutical Chemist and Scientific Instrument Manufacturer,
do hereby declare the nature of this invention to be as follows:-
My invention refers to that class of arc lamps, usually employed in connection
with lanterns, in which the carbons are held in the free ends of two levers, one or
both of which are pivotted on a centre or centres. My invention is hereinunder
described with reference to hand fed lamps; but as will be evident can be modified
so as to be applicable to automatically fed lamps.
A lamp constructed in accordance with my invention comprises two levers
pivotted on different centres or axes; the one axis being above the other. The
levers are connected by a link, the points of attachment of which to the levers are
on opposite sides of their respective axes; that is the attachment of the lower
end of the link to the bottom lever may be made on a prolongation of the lever
back beyond the axis on which it is pivotted; whilst the attachment of the top
end of the link to the top lever is made at a point forward of the axis on which
the top lever is pivotted. By this arrangement as the bottom lever moves upwards,
the top lever moves downwards, and vice versa; that is the carbons simultaneously
approach each other, or simultaneously recede from each other.
The distance of the attachment of the link to the one lever from the axis of the
lever is usually made equal to about twice the distance of the attachment of the
link to the other lever from the axis of the same lever, so as to make allowance
for the variation in the rate of consumption of the two carbons. If desired,
1 propose also to provide a slot in one or both levers, through which the pin
attaching the link to the lever passes, and in which it can be secured in any desired
position, in order to permit of a differential adjustment according to the rate at
which the carbons are consumed respectively. As such an alteration or adjustment
alters the distance between-or the position of-the link attachment pins, I either
curve the slot in one of the levers so that the length of the connecting link remains
unaltered; or I provide a slot at the lower end of the connecting link, to allow
for the alteration of the distance of the attachment pins apart.
One of the levers, conveniently the top lever, is provided with a L shaped
prolongation or arm beyond its axis; in the case of the top lever extending down-
wards. The bracket, carrying the centres on which the levers are mounted, is
provided with a milled headed screw, passing through a tapped hole in the bracket.
The end of this screw bears against the end of the above mentioned prolongation
of the upper lever, so that as the screw is screwed forwards, the top lever is
thereby tilted upwards, and the lower lever downwards. When the screw is
rotated in the opposite direction, so as to withdraw the end of the screw, the weight
of the top lever assisted by the pull of a spring (connected at one end to a fixed
point on said bracket) causes it to fall, and as above explained tilts up the lower
lever. Instead of employing a spring as just referred to, the movement of the
carbons towards each other may be effected by attaching the end of the screw to
the above mentioned prolongation, or by making the top lever sufficiently heavy.

page_text: In order to be able rapidly to strike the arc, I provide a vertical sliding piece
in the bracket, the lower end of which bears or rests on a short prolongation of
the lower lever; so that when the sliding piece is depressed, (by pressing the finger
on a button at the upper end of the sliding piece), the lower end is tilted upwards.
To prevent the depression of the sliding piece at the same time actuating the
top lever, it is necessary that the pin hole in the bottom end of the link be
slotted.
To move the arc vertically, I mount the before mentioned bracket, carrying the
axis of the levers, on a pin secured to a vertical upright or pillar, and by means
of a milled headed screw, passing through a tapped stud or boss fixed to said
upright or pillar, the said bracket and both levers can be tilted about the above
mentioned piu. The end of the screw either bears against the lower end of the
bracket, or fits capable of rotation, but incapable of longitudinal movement, in a
boss or socket attached to the lower end of the bracket, or to a lug on the same.
If necessary, the boss or socket is made capable of swivelling to suit the varying
inclination of the screw. A forward rotation of the screw tilts the bracket so as
to raise the levers, and an opposite rotation lowers or allows the levers to fall.
In order to move the arc horizontally, I attach the before mentioned upright or
pillar to the curved end of a sector shaped base plate, which is hinged or pivotted
about a vertical stud fixed in the base or stand. The length of this sector shaped
base plate is about half or greater than half the length of the levers. A curved
slot in the base plate, and a binding nut or screw passing through the slot, permit
of the levers being moved simultaneously in a horizontal direction, and on tightening
the nut or screw fixed in position.
Both the top and bottom carbon holders are hinged to the ends of their respective
levers, so that they can be adjusted to any desired inclination in a vertical plane
passing through or parallel to the levers, the screw securing the lower carbon in
ile lower holder, serving also to clamp the holder in position.
To be able to adjust the end of the top carbon vertically above the end of the
lower carbon, I provide two adjustments; the one about a horizontal axis at the
end of the top lever, and the other in a horizontal plane through the top lever.
The former adjustment consists in forming the top carbon holder as a bell crank
lever, or providing the holder with a vertical arm, which carries a tapped boss for
the screwed end of a long horizontal rod. A bearing for the back end of the rod
is provided on the top lever, and the rod is fitted with a milled head at this end.
The rod may be screwed at the part passing through this bearing instead of at
the end. By rotating the rod in one direction or the other, the top carbon holder
can be tilted in a vertical plane; i.e. about the pin on which it is hinged and by
which it is attached to the end of the top lever.
The adjustment in a horizontal plane may be effected, either by forming the end
portion of the top lever as a separate piece and hinging it about a vertical pin, to
the adjoining end of the other part of the top lever, and employing a screw
attached to the one part and a tapped hole or nut on the other part for rotating
the outer piece about the hinge pin. Or the two parts just mentioned may be made
to overlap, one end of the overlap being rigidly secured by screws or rivets, and
providing at the other end of the overlap a screw passing through a tapped hole
in the one part, and bearing against the other part carrying the carbon holder.
This other part, i.e. the outer portion of the top lever, is in this case most con-
veniently made of flat spring steel.
As it is sometimes desirable to be able to adjust the length of the lower lever,
I make the lower lever in two portions, with an overlap, and form a horizontal
slot hole through the overlapping part of one of the two portions of the lever.
A binding screw passing through the slot hole allows of the two parts of the lower
lever being clamped in any position permitted by the overlap, so as to reduce or
increase the effective length of the lower lever as desired.
The usual provision is made for insulating the outer portions of the levers.
And in order that my invention and the manner in which the same is to be

page_text: performed may be more readily and clearly understood, I have annexed hereto
the accompanying sheet of drawings, in which Fig. 1 is a side elevation on line A B
of Fig. 2, and Fig. 2 is a plan, of an arc lamp for lantern purposes constructed
according to my invention."
a a and b b are the top and bottom levers respectively, pivotted on the axes c
and d; the latter being fitted in bearings in the bracket e. The levers are con-
nected by the link f. The pin joints h and i of the link and the levers are on
opposite sides of the centres c and d respectively. The distance i. d is made greater
or less than the distance ch, as may be found advisable to counteract the tendency
of the unequal consumption of the carbons to alter the position of the arc. If
desired in order to be able to adjust the relative movements of the top and bottom
carbons, the pin joint may be made in a curved or longitudinal slot hole in the
lever a; and the pin joint in one end of the link / made through a slot hole in the
end of the link.
The top lever is provided with a prolongation l, against the lower end of which
the end of the screw m abuts. As the screw m is screwed forwards, it tilts the
top lever a a' upwards, and the bottom lever b¹ downwards. When the screw m
is rotated in the reverse direction, the spiral spring n tilts the top lever downwards,
and the lower lever upwards.
The vertical sliding rod o, which is connected to the end of the lever bb', and
passes at its upper part through the guide p. serves on pressing down the button g,
at the upper end of the rod o, to tilt up the bottom lever, and to bring the bottom
carbon in contact with the top carbon j, so as to strike the are.
To allow this,
it is necessary to slot the pin hole at the bottom end of the link f.
In order to be able to move the arc vertically, the bracket e is mounted on a
pin, fitted in the upright or pillars, and is provided on a lug at its lower end
with a bearing t for the end of the screw u. The screw u is passed through a
tapped boss or nut v, fitted (capable of slight rotation) to the upright pillar s. It
will be evident that a forward rotation of the screw u rotates or tilts up the
bracket e, and with it both the levers a a¹ and b 61; whilst an opposite rotation of
the screw lowers them.
To move the arc horizontally, the pillar or upright s is attached near the curved
end of and to the sector shaped base plate w, which is pivotted about a vertical
studa, fixed in the base slide. A curved slot is provided in the base plate w,
through which the pin or binding screw y passes, for fixing the base plate w in
any position to which it may have been adjusted.
z and are the top and bottom carbon holders, which are secured to the ends
of the levers a' and 6 by means of the screw pins 1, 1; the screw pin 1 in the
lower holder serving at the same time to secure the carbon in the holder. On
slackening back the screw pin, the lower carbon holder can be moved to any desired
inclination.
The outer portion a¹ of the lever a a' is attached to the lap piece 2 by means of
the rivets or screws 3, 3; and by means of a screw 4, passing through a tapped
hole in the end of the lap piece 2, and bearing against the outer portion of the
lever a', the top carbon can be adjusted about the lower carbon k in a direction
at right angles to the lever a¹. An adjustment of the top carbon j, with respect to
the lower carbon k in a vertical plane passing through or parallel to the levers a a¹
and 66, is effected by means of the horizontal rod 5, fitted at one end in the
bearing 6, attached to the lap plate 2, and provided with the milled head 7; the
opposite end of the rod 5 being screwed and passed through a tapped boss .8, fitted
in the end of a short vertical arm or lever 9, formed on the upper side of the top
carbon holder 2. By rotating the rod 5 in one direction or the other, the
top carbon is tilted about the screw pin 1, i.e. moved to and fro above the
lower carbon.
The last two adjustments permit of the top carbon being adjusted vertically
above, or in any other desired position with respect to the lower carbon.
The outer portion of the lower arm is fitted to the inner portion by means of

page_text: an overlap and a slotted hole in the part b, (6¹); a binding screw 10 and steady
pin 11, both passing through said slot hole into the part 61 (6) serve to permit of
the effective length of the arm b b being altered for the purpose of adjusting the
lower carbon to the back or front of the top carbon.
Dated this 30th day of October 1895.
J. CLARK JEFFERSON,
2 East Parade, Leeds, Agent for Applicant.
Improvements in Electric Arc Lamps, specially applicable for
Lantern Purposes.
I FREDERICK WOODWARD BRANSON of 14 Commercial Street Leeds in the
County of York Pharmaceutical Chemist and Scientific Instrument Manufacturer
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 :-
My invention refers to that class of arc lamps, usually employed in connection
with lanterns, in which the carbons are held in the free ends of two levers, one or
both of which are pivotted on a centre or centres. My invention is hereinunder
described with reference to hand fed lamps, but as will be evident can be modified
so as to be applicable to automatically fed lamps.
A lamp constructed in accordance with my invention comprises two levers
pivotted on different centres or axes, the one axis being above the other. The
levers are connected by a link, the points of attachment of which to the levers are
on opposite sides of their respective axes; that is the attachment of the lower end
of the link to the bottom lever may be made on a prolongation of the lever back
beyond the axis on which it is pivotted; whilst the attachment of the top end of
the link to the top lever is made at a point forward of the axis on which the top
lever is pivotted. By this arrangement as the bottom lever moves upwards, the
top lever moves downwards, and vice versa; that is the carbons simultaneously
approach each other, or simultaneously recede from each other.
The distance of the attachment of the link to the one lever from the axis of the
lever is usually made equal to about twice the distance of the attachment of the
link to the other lever from the axis of the same lever, so as to make allowance
for the variation in the rate of consumption of the two carbons. If desired,
I propose also to provide a slot in one or both levers, through which the pin
attaching the link to the lever passes, and in which it can be secured in any desired
position, in order to permit of a differential adjustment according to the rate at
which the carbons are consumed respectively. As such an alteration or adjustment
alters the distance between-or the position of the link attachment pins, I either
curve the slot in one of the levers so that the length of the connecting link
remains unaltered; or 1 provide a slot at the lower end of the connecting link, to
allow for the alteration of the distance of the attachment pins apart.
One of the levers, conveniently the top lever, is provided with a shaped
prolongation or arm beyond its axis; in the case of the top lever extending
downwards. The bracket, carrying the centres on which the levers are mounted,
is provided with a milled headed screw, passing through a tapped hole in the
bracket. The end of this screw bears against the end of the above mentioned
prolongation of the upper lever, so that as the screw is screwed forwards, the top
lever is thereby tilted upwards, and the lower lever downwards. When the screw
is rotated in the opposite direction, so as to withdraw. the end of the screw, the
weight of the top lever assisted by the pull of a spring (connected at one end to

page_text: a fixed point on said bracket), causes it to fall, and as above explained tilts up
the lower lever. Instead of employing a spring as just referred to, the movement
of the carbons towards each other may be effected by attaching the end of the
screw to the above mentioned prolongation, or by making the top lever sufficiently
heavy.
In order to be able rapidly to strike the arc, I provide a vertical sliding piece in
the bracket, the lower end of which bears or rests on a short prolongation of the
lower lever; so that when the sliding piece is depressed, (by pressing the finger
on a button at the upper end of the sliding piece), the lower end is tilted upwards.
To prevent the depression of the sliding piece at the same time actuating the top
lever, it is necessary that the pin hole in the bottom end of the link be slotted.
To move the arc vertically, I mount the before mentioned bracket, carrying the
axis of the levers, on a pin secured to a vertical upright or pillar, and by means of
a milled headed screw, passing through a tapped stud or boss fixed to said upright
or pillar, the said bracket and both levers can be tilted about the above mentioned
pin. The end of the screw either bears against the lower end of the bracket, or.
fits capable of rotation, but incapable of longitudinal movement, in a boss or
socket attached to the lower end of the bracket, or to a lug on the same.
necessary, the boss or socket is made capable of swivelling to suit the varying
inclination of the screw. A forward rotation of the screw tilts the bracket so
as to raise the levers, and an opposite rotation lowers or allows the levers to fall.
If
In order to move the arc horizontally, I attach the before mentioned upright
or pillar to the curved end of a sector shaped base plate, which is hinged or pivotted
about a vertical stud fixed in the base or stand. The length of this sector shaped
base plate is about half or greater than half the length of the levers. A curved
slot in the base plate, and a binding nut or screw passing through the slot, permit
of the levers being moved simultaneously in a horizontal direction, and on
tightening the nut or screw fixed in position.
Both the top and bottom carbon holders are hinged to the ends of their
respective levers, so that they can be adjusted to any desired inclination in a
vertical plane passing through or parallel to the levers, the screw securing the
lower carbon in the lower holder, serving also to clamp the holder in position.
To be able to adjust the end of the top carbon vertically above the end of the
lower carbon, I provide two adjustments; the one about a horizontal axis at
the end of the top lever, and the other in a horizontal plane through the top
lever.
The former adjustment consists in forming the top carbon holder as a bell crank
lever, or providing the holder with a vertical arm, which carries a tapped boss for
the screwed end of a long horizontal rod. A bearing for the back end of the rod
is provided on the top lever, and the rod is fitted with a milled head at this end.
The rod may be screwed at the part passing through this bearing instead of at
the end. By rotating the rod in one direction or the other, the top carbon holder
can be tilted in a vertical plane; i.e. about the pin on which it is hinged, and by
which it is attached to the end of the top lever.
The adjustment in a horizontal plane may be effected either by forming the end
portion of the top lever as a separate piece and hinging it about a vertical pin to
the adjoining end of the other part of the top lever, and employing a screw
attached to the one part and a tapped hole or nut on the other part for rotating
the outer piece about the hinge pin. Or the two parts just mentioned may be
made to overlap, one end of the overlap being rigidly secured by screws
or rivets, and provided at the other end of the overlap a screw passing through a
tapped hole in the one part, and bearing against the other part carrying the carbon
holder. This other part, i.e. the outer portion of the top lever, is in this case
most conveniently made of flat spring steel.
As it is sometimes desirable to be able to adjust the length of the lower lever, I
make the lower lever in two portions, with an overlap, and form a horizontal slot hole
through the overlapping part of one of the two portions of the lever. A binding

page_text: screw passing through the slot hole allows of the two parts of the lower lever being
clamped in any position permitted by the overlap, so as to reduce or increase the
effective length of the lower lever as desired.
The usual provision is made for insulating the outer portions of the levers.
And in order that my invention and the manner in which the same is to be
performed may be more readily and clearly understood, reference is to be had in
the following description to the drawings accompanying my Provisional Specifi-
cation in which Fig. 1 is a side elevation on line A B of Fig. 2, and Fig. 2 is a
plan, of an arc lamp for lantern purposes constructed according to my invention.
a a and bare the top and bottom levers respectively, pivotted on the
axes c and d; the latter being fitted in bearings in the bracket e. The levers
are connected by the link f. The pin joints h and i of the link and the levers are
on opposite sides of the centres c and d respectively. The distance i. d. is made
greater or less than the distance eh, as may be found advisable to counteract the
tendency of the unequal consumption of the carbons to alter the position of the
arc. If desired in order to be able to adjust the relative movements of the top
and bottom carbons, the pin joint may be made in a curved or longitudinal slot
hole in the lever a; and the pin joint in one end of the link made through a slot
hole in the end of the link.
The top lever is provided with a prolongation 1, against the lower end of which
the end of the screw m abuts. As the screw m is screwed forwards, it tilts the top
lever a a upwards, and the bottom lever b¹ downwards. When the screw mis
rotated in the reverse direction, the spiral spring n tilts the top lever downwards,
and the lower lever upwards.
The vertical sliding rod o, which is connected to the end of the lever bb, and
passes at its upper part through the guide p, serves on pressing down the button q,
at the upper end of the rod o, to tilt up the bottom lever, and to bring the bottom
carbon in contact with the top carbon j, so as to strike the arc. To allow this it
is necessary to slot the pin hole at the bottom end of the link f.
In order to be able to move the arc vertically, the bracket e is mounted on a
pin r, fitted in the upright or pillar s, and is provided on a lug at its lower end
with a bearing t for the end of the screw u. The screw u is passed through a
tapped boss or nut e, fitted (capable of slight rotation) to the upright pillar s. It
will be evident that a forward rotation of the screw a rotates or tilts up the bracket e,
and with it both the levers a a' and bb'; whilst an opposite rotation of the screw
lowers them.
To move the are horizontally, the pillar or upright s is attached near the curved
end of and to the sector shaped base plate w, which is pivotted about a vertical
studa, fixed in the base slide. A curved slot is provided in the base plate w,
through which the pin or binding screw y passes, for fixing the base plate w in any
position to which it may have been adjusted.
2 and 2 are the top and bottom carbon holders, which are secured to the ends of
the levers a and b by means of the screw pins 1, 1; the screw pin 1 in the lower
holder serving at the same time to secure the carbon in the holder.
slackening back the screw pin, the lower carbon holder can be moved to any
desired inclination.
On
The outer portion a' of the lever a a' is attached to the lap piece 2 by means of
the rivets or screws 3, 3; and by means of a screw 4, passing through a tapped
hole in the end of the lap piece 2, and bearing against the outer portion of the
lever a', the top carbon j can be adjusted about the lower carbon k in a direction
at right angles to the lever a¹. An adjustment of the top carbon; with respect to
the lower carbon k in a vertical plane passing through or parallel to the levers a a¹
and bb, is effected by means of the horizontal rod 5, fitted at one end in the
bearing 6, attached to the lap plate 2, and provided with the milled head 7; the
opposite end of the rod 5 being screwed and passed through a tapped boss 8, fitted
in the end of a short vertical arm or lever 9, formed on the upper side of the top
carbon holder 2. By rotating the rod 5 in one direction or the other, the

page_text: top carbon is tilted about the screw pin 1, ¿.e. moved to and fro above the lower
carbon.
The last two adjustments permit of the top carbon being adjusted vertically above,
or in any other desired position with respect to the lower carbon.
The outer portion 6 of the lower arm is fitted to the inner portion by means of
an overlap and a slotted hole in the part b, (b); a binding screw 10 and steady
pin 11, both passing through said slot hole into the part 6 (6) serve to permit of
the effective length of the arm 66 being altered for the purpose of adjusting the
lower carbon to the back or front of the top carbon.
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 :-
1. The combination of a pair of hinged levers carrying at their free ends the
carbon holders, and connected together by a link attached to the levers on opposite
sides of their respective axes, one of the levers being provided with a short arm
acted upon by a screw, whereby the carbons are made to approach each other
simultaneously, or recede from each other simultaneously.
2. The combination of a bracket e carrying the carbon levers a a¹ and b b¹,
upright on pillars to which the bracket e is hinged, and screw u, for the purpose
of adjusting the arc vertically.
3. The means for adjusting the arc horizontally consisting in the attachment of
the bracket or the upright to one end of a base piece, provided at the same end
with a curved slot hole and binding screw or nut, the opposite forward end of
the base piece being hinged to a vertical pin in the base or slide fitting the
lantern case.
4. The combination of a hinged or pivotted carbon holder with means for
rotating the holder about the hinge or pivot, substantially as herein set forth and
illustrated.
5. The combination with the means for adjusting the top carbon holder in a
vertical plane, of means for adjusting the same horizontally, all substantially as
herein set forth and illustrated.
6. In arc lamps for lantern and other purposes the employment of a lower
carbon arm or lever divided into two portions, with means for sliding and adjusting
the one portion along the other portion for the purpose of altering the effective
length of the lever.
7. In are lamps for lantern and other purposes, the means for moving the lower
carbon lever or arm independently of the upper lever or arm for the purpose of
striking the arc, substantially as herein set forth and illustrated.
8. My improved arc lamp for lantern and other purposes substantially as herein
set forth and illustrated.
Dated this 30th day of October 1895
J. CLARK JEFFERSON,
2 East Parade, Leeds, Agent for Applicant.