Improvements in Apparatus for Insulating Electric Wires or Conductors.
Year: 1893

page_text: Date of Application, 5th Jan., 1893
Complete Specification Left, 5th Oct., 1893-Accepted, 11th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Insulating Electric Wires or
Conductors.
We, ROOKES EVELYN BELL CROMPTON, Engineer, and HERBERT JOHN
DOWSING Engineer, both of Mansion House Buildings in the City of London do
hereby declare the nature of this invention to be as follows:-
In carrying out the process of insulating wires by attaching them to the surface
of plates by means of various enamels which liquify at a high temperature; we
have met with some difficulty in retaining the conducting wires in their due and
proper condition in relation to the supporting plates at such times as the insulating
materials are in a liquid or semi liquid condition. The difficulty is increased by
the fact that the wires to be embedded in the enamel frequently require to be
wound into complicated forms in order that we may obtain the desired result of
using great lengths of wire and hence a high resistance.
It is difficult by hand work to place and maintain the wire in position whilst the
enamel is in a sufficiently plastic condition to hold it. We have therefore devised
the following tool by means of which the wires may be prepared beforehand and be
placed in the desired position so as to be ready to be transferred by an instantaneous
operation from the tool to the prepared plastic enamelled surface. One way of
making this tool is the following. We provide the plate of a material which can
be exposed to sufficiently high temperatures for our purpose without fear of
distortion or damage, for instance the plate may be of various metals or it may be
of porcelain or of other similar refractory material. This plate must be provided
with a handle and the working surface of it must be flat or it may be grooved or
pierced with holes through which the ends of the wires may be threaded. In using
this tool we prepare and wind the wire into the desired pattern on the prepared
surface of the tool itself being aided by any convenient arrangement of pins, ribs
or other projections to retain the wire in position or we sometimes can prepare the
flat surface of the tool by coating it with an adhesive mixture consisting of an
even film of a composition which becomes plastic and adhesive when heated to a
low temperature i.e. a temperature considerably below that at which the enamel
itself melts. By heating the tool the adhesive coating can be raised to the
temperature at which it becomes sufficiently adhesive to retain and hold in position
the wire which may be placed on it.
The next process is to transfer the wire thus attached to the tool to the prepared
surface of the enamel supporting plate which is itself in an adhesive condition on
account of the semi liquid state of its enamel coating. By bringing the surface of
the tool armed with wire as above described into contact with the enamel covered
plate the superior heat of the melted or partially melted enamel raises the tem-
perature of the adhesive composition on the tool so much that the wire is immediately
released from the tool and remains in position attached to the enamel. The tool
may be again evenly coated with adhesive composition and again armed with wire
ready for application to another plate. In cases where the wire is wound round
projections or pins on the surface of the tool we provide a false surface to the tool
which is free to move in relation to the pins so that when the wire is wound into
the desired form on the pins or projections it can be applied to the enamel surface
and the wire can be lifted or detached from the pins or projections by the false
surface being moved so as to push the wire off the pins or projections.
Another mode of carrying out the same arrangement is the following.
In certain cases when we are using wires of either iron or steel or other alloys
of a sufficiently magnetic nature we can form the tool as an electro-magnet in such

page_text: a manner that the working surface can be made to attract the wire and hold it
firmly in position.
This can be done by arranging the working surface either as a pair of poles or
several multiple poles of a simple or a compound electromagnet.
After the wire has been wound and arranged in the desired form by laying this
electric magnetic tool over it in its non-magnetic condition i.e. before the current
is switched on to its coils and then switching ou the current so as to make the
surface of the tool strongly magnetic the wire can be lifted up and will be found to
be held firmly attached to the surface of the tool. We can then apply it to the plastic
enamelled surface of the plate and by then switching the current off from the
magnet the working surface of the tool ceases to be magnetic so that it can be
readily detached leaving the wire firmly embedded in the enamel.
Dated this 5th day of January 1893.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Insulating Electric Wires or
Conductors.
We, ROOKES EVELYN BELL CROMPTON, Engineer, and HERBERT JOHN
DOWSING, Engineer, both of Mansion House Buildings in the City of London, 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:
In carrying out the process of insulating wires by attaching them to the surface
of plates by means, of various enamels, which liquify at a high temperature we have
met with some difficulty in retaining the conducting, wires in their due and proper
condition in relation to the supporting plates at such times as the insulating
materials are in a liquid or semi liquid condition.
The difficulty is increased by the fact that the wires to be embedded in the
enamel frequently require to be wound into complicated forms. in order that
we may obtain the desired result of using great lengths of wire.and hence a high,
resistance.
It is difficult by hand work to place, and maintain the wire in position whilst the
enamel is in a sufficiently plastic condition to hold it. We have therefore devised
the following tool by means of which the wires may be prepared before hand and
be placed in the desired position so as to be ready to be transferred by a rapid,
operation from the tool to the prepared plastic enamelled surface.
One way of making this tool is the following..
We provide the plate of a material which can be exposed to sufficiently, high
temperature for our purpose without fear of distortion or damage, for instance the
plate, may be of various metals or it may be, of porcelain or, of other similar.
refractory material as for instance asbestos,sheet.
This plate may be provided with a handle and the working surface of it may be
flat or it may be grooved or pierced with holes, through which the ends of the wires.
may be threaded or the wires, may, be secured thereto by sewing, using a filament.
which can be charred or destroyed in the subsequent heating. In either case the
objecs is to hold the heating wires or resistances in their proper positions until they
are taken hold of, and imprisoned by the enamel, the temporary holder.. being
removed or destroyed in the process.
+
In using, this tool we prepare and wind the wire in any suitable, way to the
crimped or circuitous pattern we wish it approximately to retain and then we apply,
it to the face of the tool and keep it in place, thereon as will be described.
Fig. 1. a vertical section of one, form of tool, herein, shewn as a circular-tool to
hold a helical wavy circuit wire.

page_text: Fig. 2. is a face view of the plate e¹ through which the pins e² attached to the
back plate e project and on these pins the wire b is held, until the tool having been
pressed against the heated enamel surface of the plate to which the wire is to be
attached, when the plate e¹ is forced off the pins e by its stem e³ as is indicated by
Fig. 3 and the wire b is left on the enamelled plate.
Fig. 4 is a face view of the front plate e' shewing the holes
pins e² pass.
0
through which the
Fig. 5 shews another form of the tool in which the retaining force is attained by
a current being passed through the lead e to the electro magnets e' the faces of
which serve to attract and hold the wire b.
Fig. 6 shews in part (the left hand half) a face view of the holding surfaces e' and
in part (the right hand half) a transverse section of the stems or magnets around
which the wire or lead e is wound.
Figs. 7 and 8 shew by section and under side view a simple form of the foregoing
principle of construction with the stem e³ wound with the exciting wire and the
holding face of the magnet in one piece.
Fig. 9 shews a section of a simple form of tool in which the adhesive quality of a
glutinous film applied on the face el of the tool is made to serve as the holding.
means for the wire b pro. tem. until by pressure thereof on the plate a coated, with
enamel in an adhesive condition it becomes transferred.
Fig. 10 shews a face view of the tool with the wire thereon and
Fig. 11 a like view of the plate a with the wire transferred to it.
Fig. 12 shews a section taken through the middle of the plate a.
In some cases it may be found convenient instead of first preparing it to wind the
wire into the desired pattern on the prepared surface of the tool itself being aided
by any convenient arrangement of pins, ribs or other projections to retain the wires
in position.
In cases where the wire is wound round projections, blades or pins on the surface
of the tool we provide a false surface to the tool which is free to move in relation
to the pins so that when the wire is wound into the desired form on the pins
or projections it can be applied to the enamel surface and the wire can be lifted or
detached from the pins or projections by the false surface being moved so as to push
the wire off the pins or projections.
We sometimes can prepare the flat surface of the tool by coating it with an
adhesive mixture consisting of an even film of a composition which becomes plastic
and adhesive when heated to a low temperature i.e.-a temperature considerably
below that at which the enamel itself melts.
By heating the tool the adhesive coating can be raised to the temperature at
which it becomes sufficiently adhesive to retain and hold in position the wire which
may be placed on it.
The next process is to transfer the wire thus attached to the tool to the prepared
surface of the enamel supporting plate which is itself in an adhesive condition on
account of the semi-liquid state of its enamel coating. By bringing the surface of
the tool armed with wire as above described into contact with the enamel covered
plate the superior heat of the melted or partially melted enamel raises the
temperature of the adhesive composition on the tool so much that the wire is
immediately released from the tool and remains in position attached to the enamel.
The tool may be again evenly coated with adhesive composition and again armed
with wire ready for application to another plate.
Another mode of carrying out the same arrangement is the following.
In certain cases when we are using wires of either iron or steel or other alloys of
a sufficiently magnetic nature we can form the tool as an electro-magnet in such a
manner that the working surface can be made to attract the wire and hold it firmly
in position.
This can be done by arranging the working surface either as a pair of poles or
several multiple poles of a simple or a compound electroinnet. After the wire
has been wound and arranged in the desired form by laying this electric magnet tool

page_text: over it in its non magnetic condition i.e. before the current is switched on to its coils
and then switching on the current so as to make the surface of the tool strongly
magnetic the wire can be lifted up and will be found to be held firmly attached to
the surface of the tool, we can then apply it to the plastic enamelled surface of the
plate and by then switching the current off from the magnet the working surface of
the tool ceases to be magnetic so that it can be readily detached leaving the wire
firmly embedded in the enamel.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what we
claim is
1. The herein before described means or apparatus for temporarily retaining
resistances in the manufacture of enamel plates or surfaces carrying insulated wires
substantially as and for the purposes set forth.
2. In the manufacture of enamelled plates or surfaces having embedded wires or
resistances, the employment of holding and retaining means in which the attractive
force of electro magnetism is utilized substantially as set forth and shewn by the
drawings.
Dated the 4th day of October. 1893.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London, Agents for the Applicants.