Year: 1898

page_text: LOUIS JOHN STEELE, 14, Clarendon Road, Holland Park, London, in the County
of Middlesex, Electrical Engineer, do hereby declare the nature of this invention
to be as follows.
My invention relates to electrical resistances and rheostats designed to obtain
a high resistance in a small space with a given wire or strip The wire or strip
is first wound in the form of spirals or corrugations, and 18 then spirally wound
1ound an insulating support formed of porcelain or other suitable material con-
taining recesses for receiving the resistance, or the spials may be kept from
touching one another by placing insulation between them Connections are tapped
at different points in the wires, these tappings being led along or through the
insulating support in such a manner as to be kept from touching one another
These connections formed preferably of metal strip attached to the resistance are
arranged to form a set of contacts secured to the insulating support itself, or to an
auxiliary insulator mounted on the support A metallic arm fixed to a handle
slides over these contacts, in the usual way causing current to pass through
different portions of the resistance It is apparent that the contact arm may be
fixed and the support carrying the resistances and contacts may be rotated. Where
I wish to obtain a very gradual alteration of the resistance, I wind the above
alangement in spirals round the circular insulating support so mounted that it
can be rotated on its axıs Connection is made to the iesistance by a system of
contacts mounted on a guide 1od and so aanged that the rotation of the insulating
support will cause the contact to travel gradually from one end of the resistance
to the other In some cases the we may be formed of three or more systems
of spials by first winding the resistance spirally on a removable mandril, then
winding the spiral so formed spirally round another removable mandril, and so on.
In some cases I do not wind the spiralled wire round an insulating support
but carry it on terminals in the same manner as the ordinary single spiral
resistances used for resistance frames
Another method of supporting the wire consists in winding the wires spirally
1ound an insulated mandril, the mandril itself covered with the wire may then
be wound in the form of a spial or system of spirals as above described By
the use of the spiral mandril the internal insulating support may be dispensed
with.
1000

page_text: Improvements in Electrical Rheostats and Resistances.
I, LOUIS JOHN STELLE, of 14, Clarendon Road, Holland Park, London, W,
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 electrical rheostats and resistances and consists in
certain improvements therein which have for their object the attainment of a
high electrical resistance with a given quantity of wire or strip, and the design.
of an appliance of small dimensions and of a neat and compact form
According to one form of this invention when applied as a 1heostat, the wire
or stip of metal of which the resistance is built up is first wound in the form of
spirals or corrugations, or is coiled into. a long length piece upon a spit, and is
then again bodily wound spally into a multiple coil 1ound an insulating support
having upon its cicumference un helical groove or recess for its reception, each
convolution or winding being distanced by the intervening web which separates
the parts of the groove The multiple coil so formed is of a compound order, that
18 to say, the wire or strip length has been spirally coiled twice, the last time, as
it were, upon itself. Connections are tapped at different points in this compound
spiral oi helix which are led along through the insulating support in separate
grooves, so that they are entuely separated the one from the other. These con-
nections, which are preferably formed of stip metal, terminate in a set of contacts
carried upon an insulating block, connected to one of the ends of the resistance
support as aforesaid and which is fitted with a shifting switch arm adapted to
engage the said contacts in the usual way and being coupled to the electrical
circuit
In the accompanying sheet of drawings a rheostat so constructed is shown in
Figs 1, 2, 3 and 4, the views showing respectively an elevation, a part longitudinal
section, a horizontal section, and a top-side plan The compound helix a is wound
within a groove a formed around the cucumference of a cylindrical insulating
support, and each convolution is separated by the intervening web e The
insulating support 18 mounted upon a suitable base d, and a porcelain or similar
block e is attached to its other end for carrying the contacts g and the switch
arm foi regulating and adjusting the resistance, the said switch aim and contacts
being wired up in the circuit as ordinarily Metallic connections m are tapped
to the compound spiral or helix a at the points shown, and lead to the different
contacts g, the said connections being arranged longitudinally within separate
grooves n formed at certain distances apart within the support inwards of the
groove c The one end of the compound coil is connected to one of the contacts g,
and the other end to a terminal or other suitable device in the circuit, and the
said coil is enclosed in the casing s
It will be obvious from the figs of the drawings as to the high resistance which
can be obtained by such a building up and formation of the appliance, and this
in an appliance of small dimensions.
If desired the insulating support may be dispensed with, in
coil a would be amply strung between two terminal supports
shown in diagram on the sheet of drawings at Fig 5, the coil
pound construction the same as before described
which case the
Such a form is
being of a com-
The coil a constructed as aforesaid may be applied as a theostat in accordance
with the diagram Fig 6 on the sheet of drawings In this form a very gradual
alteration or adjustment of the amount of resistance can be effected, as the said
coil on apual a is carried upon an insulating support mounted on an axis so as

page_text: to be capable of rotation, the contact m, or the system of contacts as the case may
be, being mounted upon a guide rod m³ so that it or they can follow up the rotation
of the insulating support so as to bear upon different convolutions or points of the
coil, and be capable of travelling gradually from the one end of the cou to the other.
In another form of this invention the coil 18 built up of three or more systems
of windings, for example, in the diagram Fig 7 the coil comprises three windings,
the strip or wire forming it being fust wound up on a spit into a long length
spiral, then wound again upon another spit to form a spial as in Figs 1 and 2,
and then subsequently this compound coil 18 again wound into a triple coil.
Additional windings may subsequently take place in order to obtain the required
high resistance. in Fig. 8 of the drawings a diagram shows a modification
of Fig. 7. In this case a 'tiple coiled resistance has wound up with it at its last
winding a flexible insulating mandi el or spit, o, as a support, the said mandrel
being of such a nature as to constitute a sufficiently rigid mounting to keep the
convolutions of the coil in their place
If found necessary such a central support may be wound in the interior of the
helix in the winding up and formation of a compound coil
It will be obvious to anyone connected with this art of the applicability of this
invention to ordinary resistances which are distinctive from rheostats.
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 18.-
First. An electrical resistance or rheostat characterised by a multiple coil or
spiral formed from a single metallic wue o stup length by a multiplicity of
windings or coilings for the purpose and in the manner described and set forth
Second. In electrical resistances, the use of a multiple coil or spial, or a number
of same, which 18, or are, formed separately, or together, by a multiplicity of
windings or coilings of a wire or atrip length, or a number of same, for the purpose
described
Third. An electrical resistance or rheostat built up of a multiple coil or spiral
formed of a single metallic stup or wire length by a multiplicity of windings or
coilings, an insulating support having upon its circumference an helical groove
or recess and a spacing web, and electrical connections, contacts, and switch arm,
substantially as described and set forth
Fourth An electrical resistance or rheostat distinguished by a multiple coil
or sparal formed from a single metallic wire or strip length by a multiplicity of
windings or coilings, and a flexible insulating mandrel or spit which is wound
within the said coil and forms its central support, and which may be continuous
throughout the coil or present only in a number of its windings, substantially as
described.
Fifth. A rheostat or adjustable resistance coil constructed arranged and fitted
substantially as set forth in Figs 1 to 4, and also in Fig 6.
day
1000,
W P. THOMPSON & Co,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London, and Manchester,
Patent Agents for the Applicant