Improvements in and relating to Induction Coils for Medical Purposes.
Year: 1894

page_text: Date of Application, 11th July; 1894-Accepted, 25th Aug., 1894
COMPLETE SPECIFICATION.
Improvements in and relating to Induction Coils for Medical
Purposes.
We, ARTHUR CHEETHAM of Queen Street Rhyl, in the County of Flint, North
Wales, Medical Electrician, and FREDERICK BROWN of The Walsall Electric
Company, Limited, Bridge Street, Walsall, in the County of Stafford 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 the improvements hereinafter described, in induction
coils for medical purposes and consists in the arrangement whereby the two ends of
the core are extended and brought together so that both poles are presented to the
contact breaker which obviously will strengthen the magnetic field and the contact
breaker will work much better with the current than heretofore.
Our invention consists further in an improved arrangement by which the
induction effected in the secondary, is regulated by a brass or other suitable tube
working in a tubular guide, the said tube being moved in and out between the core
and the primary, movement being effected by a stud or its equivalent attached to
the brass tube aforesaid, working in a slot formed in the tubular guide and engaging
in a spiral grove in the form of a helix formed on a cylinder which may be made
either of wood or metal. The said cylinder being rotated by means of a handle
attached to a spindle which passes through the cylinder, each end thereof working
in bearings. The said handle being at the top of the base plate rotates around a
circle which is indexed with printed figures to indicate the position and show the
comparative power of the induced current, the arrangement thus described being
more simple and effective than others at present in use.
We will now proceed to describe our invention by reference to the accompanying
drawings, the letters of reference indicating similar parts throughout.
Figures 1, 2, 3 and 4 show sectional elevation and plan respectively of a box A
containing the mechanism described.
E and E show the two ends of the core C extended at C1 and C and brought
together so that both poles are presented to the contact breaker F, thus strengthening
the magnetic field, the core C₁ being broken at C³ to allow of the brass tube B
sliding up and down which is a small gap for the magnet lines to leap and faciliating
the work of the current..
The induction effected in the secondary regulated by a brass tube B sliding in
the tubular guide I, which is moved in and out of the core C by the stud H sliding
in the spiral slot J formed in the cylinder K which rotates by means of the
spindle N working in the bearings O, O¹, the movement being effected by means of
the handle M attached to the spindle.
In Figures 1 and 2 the brass tube B is shown between the core and the primary
and the handle M in its normal position, by moving the handle M around the
indexed circle towards 12 as shown in Figures 3, and 4, the induction is effected in
the secondary by the tube B which is removed from the core and primary to the
tubular guide I by means of the stud H sliding down the spiral slot J to the base
thereof, thus the handle M will show by its position on the indexed circle the
comparative power of the induced current.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
(1.) The improvements in and relating to induction coils for medical purposes as
herein described and illustrated in Figures 1, 2, 3 and 4 of the accompanying
drawings and for the purpose set forth.
(2.) In the arrangement whereby, the two ends of the core are extended and
brought together so that both ends of the poles are presented to the contact breaker
so as to strengthen the magnetic field, substantially as herein described and
illustrated in the drawings.
(3.) In the induction effected in the secondary by means of the. sliding tube or
its equivalent moving between the core and the primary by means of the pin H
working in the spiral grove on the cylinder, combined and operating substantially
as described and illustrated in the drawings and for the purpose set forth...
Dated this 10th day of July 1894.
WILLIAM HENRY BARACLOUGH,
36, Temple Street, Birmingham, Agent for the Applicants.