Improvements in Electrical Resistance Coils.
Year: 1892

page_text: Date of Application, 29th Nov., 1892
Complete Specification Left. 10th Aug.. 1893-Accepted, 16th Sept., 1893
PROVISIONAL SPECIFICATION.
Improvements in Electrical Resistance Coils.
We, SIEMENS BROTHERS & Co. LIMITED of 12 Queen Anne's Gate, West-
minster in the County of Middlesex and JOHN NEBEL of 74 Woodland Terrace,
Old Charlton in the County of Kent do hereby declare the nature of this
invention to be as follows:-
This invention relates to
a simple and strong construction of electrical
resistance coils in the following manner. A wire, preferably of low conductivity,
is coiled into a helix with its convolutions sufficiently far apart to prevent short
circuiting. This helix is enclosed in a tube, which may be of iron and which is
lined internally with enamel, asbestos or other suitable insulating material. After
introducing the wire helix the tube is filled with saud or other granular insulating
material, and its ends are closed by insulating plugs, which may be of slate,
ceramic material or the like, held by screw caps or by other suitable means, the
ends of the wire passing through these plugs to the outside, so that they can be
connected in any circuit to which the resistance is to be applied.
Dated this 29th day of November 1892.
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Electrical Resistance Coils.
We, SIEMENS BROTHERS & Co. LIMITED, of 12 Queen Anne's Gate, West-
minster, in the County of Middlesex, and JOHN NEBEL, of 74 Woodland Terrace,
Old Charlton in the County of Kent, 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 a simple and strong construction of electrical resistance
coils in the following manner. A wire preferably of low conductivity, is coiled
into a helix with its convolutions sufficiently far apart to prevent short circuiting.
This helix is enclosed in a tube, which may be of iron and which is lined
internally with enamel, asbestos or other suitable insulating material. After
introducing the wire helix the tube is filled with sand or other granular insulating
material, and its ends are closed by insulating plugs, which may be of slate,
ceramic material or the like, held by screw caps or by other suitable means, the
ends of the wire passing through these plugs to the outside, so that they can be
connected in any circuit to which the resistance is to be applied.
Fig. 1 of the accompanying drawings is a side view partly in section of a resistance
coil according to this invention. T is the metal tube with insulating lining L,
containing the helical coil H imbedded in sand or the like. P is the insulating
plug, held in position by a cap C screwed outside the tube, or, as shewn in Fig. 2,
secured by a bayonet catch B, Fig. 3 shews the insulating plug P held by a metal
plug M screwed into the tube T.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
An electrical resistance coil consisting of a wire helix of low conductivity

page_text: imbedded in insulating granular material within a metal tube lined with insulating
material and closed at the ends by insulating plugs through which the wire passes,
substantially as described.
...
C A
1000
ABEL & IMRAY,
Agents for the Applicants.