Improvements in Electric Condensers.
Year: 1897

page_text: Date of Application, 27th July, 1897-Accepted, 4th Sept.,
1897
QUALI MEIE DIMUITICATION.
Improvements in Electric Condensers.
I, CHARLES SCHENCK BRADLEY, of Avon, in the County of Livingston, and State
of New York, United States of America, 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:
-
This invention relates to electric condensers, the object being to increase the
safety of the condenser under dielectric strain of abnormal voltage, to increase
its life and preserve its capacity uniform and to reduce the extent of its heating
when in service. To accomplish these aims I provide an air-tight case adapted to
contain the plates constituting the condensing surface with a nozzle by which
it may be treated and filled with any suitable insulating material, such as paraffine,
oil, or wax, and fit the nozzle with an air-tight cap, thus preventing the penetration
of damp air or moisture. In close relation to the plates but thoroughly insulated
therefrom I place metal surfaces or plates which afford a good heat conductive
path to the outside where the radiating surface is increased, thus permitting the
withdrawal of heat, and maintaining a safe temperature of the apparatus when in
service. I preferably employ a solid dielectric, such as mica, and hold the plates
in compact relation by an independent frame capable of being screwed up so as to
squeeze the plates firmly together. The points where the terminals are carried
through the containing case are carefully sealed, and the joint between the leading-
in wires or conductors and the terminals are housed over by an insulating cap to
prevent accident to an attendant.
In the accompanying drawings which illustrate my invention
Figure 1 is a side elevation of a condenser embodying my improvements, the
condenser plates being indicated diagrammatically.
Figure 2 is a vertical section on a plane passing through one of the terminals.
1 represents a rim or outer wall of the containing case; this is made of metal
and of a sufficient size to enclose the pile of plates of mica and tinfoil, of which
the condenser proper is preferably composed. These plates are indicated at 2;
sufficient room is left between the edges of the plates and the rim 1 to permit a
good body of insulating material to be filled in. At opposite sides of the pile
alternate plates of foil are connected in parallel and soldered or otherwise fastened
in good conductive relation to the terminal conductors 3, 3ª The sides of the
pile are embraced by metallic plates 4, 4ª, preferably of tin, against which bear the
metal stiffening plates 5, 5ª of cast iron from which extend arms as 6, the ends
of which are perforated to receive clamping bolts 7. After assembling the pile
and connecting alternate plates of foil with the respective terminals, they are
placed within the rim, and the side plates 4, 4" are brought against them, a layer of
mica being interposed at the two sides. The frame is then applied and the nuts
firmly screwed up on the bolts. The joints between the edges of the rim and the
plates 4, 4 are then soldered together. One side of the rim is perforated at three
points 8, 8, 9; a nozzle is soldered in the latter and threaded to receive a screw-
cap 10. In the holes 8, 8ª are soldered bushings 11, through which screws a

page_text: plug 12 of insulating material, within which is a threaded bolt for making
connections with the terminal conductors and with the leading-in conductors,
as 13, at. its respective ends. A cap of insulating material 14 is screwed over
the terminal connections to prevent contact of the hand of an attendant with any
live spot of the apparatus. The flanges on plates 4, 4", shown in Figure 2, permit
the frame to be adjusted to varying thicknesses of the pile of plates. When the
capacity of the condenser is adjusted, plates may be inserted or withdrawn until
the desired capacity is attained, when the bolts are tightened and the joint soldered.
By the construction herein described moisture from the atmosphere outside the
condenser is effectually kept from access to the plates and they are preserved in
the same condition as when first assembled. By being kept under firm pressure,
the noise commonly made by vibration of the plates is reduced. The heat
generated is conducted away by the metallic face-plates and radiated into the
atmosphere by the larger surface of the casing and frame. The casing is protected
from damage due to shock by the stout compressing and radiating frame. By
soldering the joints, leakage is effectually prevented if the heat generated by the
condenser rises sufficiently high to melt the insulating material.
Having thus described my invention and particularly ascertained the nature
thereof, and in what manner the same is to be performed, I declare that what I
claim is:-
1. An electric condenser having its condensing plates and dielectric enclosed
air-tight in a metallic casing hermetically sealed at the joints to exclude moisture
of the air and preserve the condenser's capacity unaltered.
2. An electric condenser having its plates held between stiff side plates, and a
rim soldered to the side plates while compressed.
3. An electric condenser having its plates held under pressure in an air-tight
casing by a strong frame projecting beyond the edges of the casing.
4. An electric condenser having its plates in an air-tight casing enclosed within
a strong metallic frame having a large heat radiating surface.
Dated this 27th day of July A.D. 1897.
BOULT & WADE,
Agents for the Applicant.