Improvements in Electric Arc Lamps.
Year: 1897

page_text: Improvements in Electric Arc Lamps.
I, WILLIAM ERNEST BURNAND, of 31 Edgehill Road, Netheredge, Sheffield, in the
County of York, Electrician, do hereby declare the nature of this invention to be as
follows:
This invention relates to electric lamps, and it consists of improvements in the
construction and mechanism of such lamps, and devices. In my improved lamp I
separate the case containing the mechanism from the reflector; the latter being held
in position by brackets secured to the underside of the the aforesaid case.
In my improved lamp the space between the case containing the mechanism and
the reflector is not enclosed or "boxed in," but this space is left open and relieved,
and the reflector may be supported by ornamental work, which does not partake of
I also introduce
the character of a casing, such as a number of brackets or chains.
a parallel motion for regulating the feed of the top carbon, which consists of a cross
bar attached to the holder or clamp containing the carbon; the one end of this being
attached to a weight which slides in a vertical casing disposed between the reflector
and the case which contains the mechanism, and also entering it. The other end of
the aforesaid cross bar may be forked or otherwise shaped to slide freely up and down.
a suitable guide rod which is attached to the underside of the mechanism case and
top side of reflector, thereby preventing the carbon turning round. This end may be
fitted with a sliding weight as above described. My improvements in the mechanism
consist of a regulating appliance in conjunction with a retarder which is continuously
in gear with the chain wheel or carbons, and which acts so as to retard the motions of
the carbons at the time of striking the arc and also when feeding.
This retarding appliance may consist of a fan on a horizontal or vertical spindle on
which is a pinion, the teeth of which are in gear with teeth on the side of the brake
wheel. Or this wheel and pinion may be smooth and gear simply by frictional
contact. An iron core of special construction may be used in connection with the
lamp solenoid. This iron core is so shaped that when it moves with a lever or arm
upon a centre it does not touch the enclosing solenoid. This is effected by forming
the said core partly straight and partly of the shape of the segment of a circle.
The regulating mechanism may be of any suitable type, preferably of the description
illustrated and claimed in the specification of my Patent Number 3,006 dated
February 11th 1895, with the retarding appliance and special solenoid core herein
described. In such a lamp the action is as follows:-When it is trimmed ready for
use the carbons are separated slightly and the lever and detent of the brake wheel
are then in their lowest positions. When the current is switched on the iron core is
attracted into the solenoid moves the lever and detent, which in their turn move the
brake wheel. This also moves the pinion and fan, thus releasing the chain wheel and
allowing the carbons to come together slowly by gravity. When the carbons come
into contact, the current in the solenoid diminishes due to the decreased E.M.F.;
this in turn allowing the iron core to fall away from the solenoid and separate the
carbons again, thus striking the arc. As the carbons burn away the E.M.F.

page_text: increases, more current passes through the coil, and the core is drawn further into
the solenoid until a stop or catch lifts the detent from contact with the brake wheel.
This leaves it free to move and allow the carbons to come closer (the rate of their
movement. being controlled by the above described fan), till the E. M. F. diminishes
sufficiently to allow the detent to again engage with the brake wheel. Automatic
governing is thus secured, as the saine operations will continue till the carbons are
burnt away.
I, WILLIAM ERNEST BURNAND, of 31 Edgehill Road, Netheredge, Sheffield 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 :-
This invention relates to electric lamps and electro-magnetic apparatus, and
consists of improvements in the construction and mechanism of such lamps. In my
improved lamp the space between the case containing the mechanism, and a reflector
situated at a suitable distance from_said case, is not enclosed or "boxed in " but this
space is left open and relieved, and the reflector may be supported by ornamental
work, which does not partake of the character of a casing, such as a number of
brackets or chains secured to the underside of the aforesaid case. I also introduce a
new or improved form of parallel motion for guiding and regulating the feed of the
top carbon.
In order that my invention may be readily understood I shall proceed
to describe it with reference to the accompanying drawings, in which like parts
are indicated by similar letters of reference.
In the said drawings
Fig. 1 shews one form of my complete lamp, partly in sectional elevation.
Fig. 2 shews plan of same.
Fig. 3 shews parallel motion for top carbon.
Fig: 3 shews plan of same.
Fig. 4 is a larger view of solenoid core than shewn in Fig. 1.
.
Referring to Fig. 1 which shews one form of complete lamp, the regulating
mechanism is contained in the top casing Z, beneath which is supported at a
suitable distance by ornamental brackets B³ (which may be substituted by chains or
any other artistic device of like nature) the reflector T. A is the brake wheel
which has two sets of teeth, one set being bevelled so as to gear with the teeth on the
pinion B of the shaft of fan c, the other set being so arranged that the catch or
detent m² can engage therewith. Instead of having teeth the wheel A may be
smooth and gear by friction. At D is pivoted a suitably formed lever E and on this
lever at a point F is attached the spring g, at the other end of which is disposed
the catch or detent m² of any suitable shape, and at his rigidly attached the iron
core i, this iron core being so shaped that in its movements up and down with the
lever E it will in no way touch the solenoidj in which it moves.
The apparatus of the parallel motion Fig. 3 consists of a cross bar M¹ attached to the
holder or clamp M containing the carbon; to one end of the cross bar M¹ is attached a
weight s which slides in a vertical casing K disposed between the reflector and the
case which contains the mechanism, and also entering it. The other end of the

page_text: aforesaid cross bar may be forked or otherwise shaped so as to slide freely up and
down a suitable guide rod, which is attached to the underside of the mechanism
case and top side of reflector, thereby preventing the carbon turning round. This
end may also be fitted with a sliding weight as above described instead of being
forked to slide on a guide rod as shewn.
In Fig. 1. N is the bottom carbon holder which is attached to the tube or rod O
which passes through a hole in the reflector T. To the other end of this tube or
rod O is rigidly attached or formed integrally therewith, the guide piece R, the end
of which has an eye which slides perpendicularly on the rod S. The tube or rod-O
may be made of square or other suitable section in which case R and S will not be
needed. The guide piece R is attached to M by means of a chain or cord t which
passes over the guide wheel u under the wheel v on the same shaft as the brake-
wheel of a suitable shape to prevent slipping, and over guide wheel W. The
regulating mechanism may be of any suitable type but preferably of the description
illustrated and claimed in the specification of my Patent No 3,006 dated February 11th
1895, with the addition of the retarding appliance and special solenoid core
herein described.
In Fig. 4 is shewn on an enlarged scale the shape of the core i which I preferably
employ. By its use I employ the greatest possible quantity of iron in any given
size of solenoid, while at the same time preventing the core touching the inside of
the solenoid coil.
In such a limp the action is as follows:-
When it is trimmed ready for use the carbons are separated slightly, and the
lever E and detent m² of the brake wheel A are then in their lowest positions; when
the current is switched on, the iron core i is attracted into the solenoid, and moves
the lever E and detent m² which in their turn move the brake wheel A, this also
moves the pinion B and fan c (the rate of movement being controlled by fan c) until
the stop lifts the detent m² from contact with the brake wheel A and allows the
carbons to come together slowly by gravity. When the carbons come into contact,
the current in the solenoid diminishes due to the decreased E.M.F. this in turn
allowing the iron core i to fall away from the solenoid j and separate the carbons
again, thus striking the arc. As the carbons burn away the E.M.F. increases, more
current passes through the coil, and the core i is drawn further into the solenoid
until a rod k lifts the detent m² from contact with the brake wheel. This leaves it
free to move and allow the carbons to come closer, the rate of their movement being
controlled by the fan c until the E.M.F. diminishes sufficiently to allow the
detent m² to again engage with the brake wheel. Automatic governing is thus
secured as the same operations will continue until the carbons are burnt away.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:"
1. For use in electric arc lamps the parallel motion for top carbon, constructed and
operating, substantially as shewn and described.
2. For use in electric arc lamps a regulating mechanism in which a retarding device
permanently geared to the movable carbon or carbons acts so as to retard their motion
at the time of starting the arc as well as when feeding it, substantially as shewn and
described.
3. For use in electric are lamps an electro-magnetic mechanism consisting of an
iron core and a solenoid, constructed and operating. substantially as shewn and
described.
4. For use in electric are lamps an iron core adapted to a limited movement in
and out of a solenoid constructed and operating, substantially as shewn and
described.
5. In electric are lamps the combination of a casing containing a regulating
mechanism, with a reflector, separated from the casing by ornamental brackets or
chains, so as to leave the intervening space open, substantially as shewn and described.

page_text: 6. In electric arc lamps the combination of a casing containing the regulating
mechanism, with a reflector separated from the case by ornamental brackets or chains,
substantially as shewn and described.
WILLIAM J. MUNDEN.
75 Chancery Lane, London, W.C. Agent for the Applicant.