Year: 1897

page_text: I, AUGUSTUS JOHN MARQUAND, of Dock Chambers, Cardiff, Consulting Engineer,
do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in electrical resistances composed of
carbon or other material in the form of plates or sheets in a pile or column subject
to more or less pressure, and has for its object the dissipation of the heat pro-
duced in such resistances when an electrical current passes through them.
In resistances of this class as made heretofore the surface for dissipation of
the heat produced in the resistances has been the outside surface of the column
of plates of resisting material and as this with any reasonable dimensions only
enables small amount of power to be dissipated the use of such resistances has
been limited.
My invention consists in meaus or methods of increasing the cooling surface
to any required extent, and this I do in the following manner: -
Between each plate of the resisting material I place a sheet of metal such as
copper, brass, iron or zinc; the said sheet of metal being larger than the sheet of
resisting material, with the result that the pile or column of plates presents
a large surface radiating plates or gills in contact with the air; the heat from the
interior of the pile of plates being conducted to those parts of the plates which are
giving up their heat to the surrounding air.
To further increase the circulation of the air these plates may be perforated or
corrugated in any required manner.
In certain cases the plates of resisting material may themselves be used by
applying alternately plates of smaller and larger area so that the same arrange-
ment of radiating plates is presented to the air.
In very large resistances where the power to be dissipated is great a fan or
blower may be used to drive air through the radiating plates and the said fan
may be worked by an electric motor forming itself a power absorbing device, being
connected as a shunt or otherwise to the resistance requiring to be cooled.
Dated this 22nd day of March 1897.
I, AUGUSTUS JOHN MARQUAND, of Dock Chambers, Cardiff, Consulting Engineer,
do hereby declare the nature of this invention and in what manner the same is
[Price 8d.1

page_text: to be performed to be particularly described and ascertained in and by the
following statement: —
This invention relates to improvements in electrical resistances composed of
carbon or other material in the form of plates or sheets in a pile or column subject
to more or less pressure, and has for its object the dissipation of the heat pro-
duced in such resistances when an electrical current passes through them.
In resistances of this class as made heretofore the surface for dissipation of the
heat produced in the resistances has been the outside surface of the column of
plates of resisting material and as this with any reasonable dimensions only
enables a small amount of power to be dissipated, the use of such resistances has
been limited.
My invention consists in means or methods of increasing the cooling surface
to any required extent, and this I do in the following manner:-
Between each plate of the resisting material I place a sheet of metal such as
copper, brass, iron or zine; the said sheet of metal being larger than the sheet of
resisting material, with the result that the pile or column of plates presents a
large surface of radiating plates or gills in contact with the air; the heat from
the interior of the pile of plates being conducted to those parts of the plates which
are giving up their heat to the surrounding air.
To further increase the circulation of the air, these plates may be perforated
or corrugated in any required manner.
In certain cases the plates of resisting material may themselves be used by
applying alternately plates of smaller and larger area so that the same arrange-
ment of radiating plates is presented to the air.
In very large resistances where the power to be dissipated is great, a fan or
blower may be used to drive air through the radiating plates, and the said fan
may be worked by an elecric motor (forming itself a power absorbing device)
being connected as a shunt or otherwise to the resistance requiring to be cooled,
or a chimney may be fitted to the resistance pile for the same purpose.
In order that my invention may be the better understood, I now proceed to
describe the same with reference to the drawings hereto annexed and to the
letters and figures marked thereon.
Figure 1 shews a regulating resistance pile composed of two frame plates ua,
insulated on one face by enamel, or by a sheet of insulating material, and con-
nected by bolts bb, which are insulated throughout their length by enamel or
otherwise. On these are threaded alternately sheets of resisting material cc and
metal plates dd, the latter extending further than the plates of resisting material
as already described. e is a pressure plate, f a screw by which the pressure plate
is made to exert a pressure on the pile of material.
Figure 2 shews a resistance pile suitable for purposes such as an arc lamp
resistance, where, although adjustment is at times required, it is usually fixed at
some particular value. In this case the alternate plates of resisting material cc
and the metal cooling plates dd are supported on a central screw 6 insulated with
enamel or otherwise, and the pressure is adjusted by the nut g on the screw, and
when adjusted the position of the upper and lower plate a a is fixed by screws e e
at the edge of the plate. The plate a a may also be insulated with enamel or by
sheets of insulating material.
When the resistance is required to be worked rapidly, the adjusting screw fi
Figure 1, may be replaced by a cam acting on a stud or roller on the pressure
plate e as in Figure 3 where h is a cam pressing on the roller k and actuated by
the handle 1. In this case there may be a switch also actuated by the shaft on
which the cam works, and the cam may so be shaped that whilst part of its
travel acts to compress the resistance, part may have no compressing action,
allowing the switch to travel to make or break a circuit, whilst the resistance
remains unaltered.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
11
1. In an electrical resistance pile composed of sheets of resisting material in
layers whose resistance can be altered by compression; the combination with
such sheets of resisting material of interleaved sheets of metal or of similar
material as the resisting sheets of such larger dimensions, that, they may project at
the sides of the pile with air spaces between for the purpose of dissipating the
heat generated in the resistance pile substantially as described.
2. The combination and arrangement of parts forming adjustable resistance
piles comprising external frames, connections, insulation adapted to frames and
connections, resisting sheets and cooling sheets and means for effecting the com-
pression of the resistance pile, substantially as described and illustrated in
Figures 1, 2 and 3.
3. The combination with such resistance piles, having cooling plates, of means
for increasing the circulation of air to cool the resistance piles, such as a fan
worked by a motor or a chimney, substantially as described.
Dated this 17th dor of Desamba 1807
FELL & JAMES,
1, Queen Victoria Street, London, E.C., Agents for the Applicant.