Improvements in Medical Induction Coils.
Year: 1890

page_text: Date of Application, 26th Apr., 1890
Complete Specification Left, 24th Jan., 1891-Accepted, 28th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in Medical Induction Coils.
I, GUSTAVUS COHEN, of 24, Barton Arcade, Deansgate, Manchester, in the County
of Lancaster, Medical Electrician, do hereby declare the nature of this invention
to be as follows:-
My invention relates to induction coils used for medical purposes and the object
of my invention is to construct such an induction coil as to give a more regular,
steady and efficient current being simple in construction and economical in its
application especially if used for electrical treatment in baths.
To effect this object I propose to employ a bobbin made of wood or other
suitable insulating material. provide the said bobbin with an iron core made of
soft iron wire over which is fitted loosely a thin brass tube which also slides freely
in the centre opening of the said bobbin so that the tube can be easily inserted or
withdrawn. Around said bobbin I wind several layers of insulated stout copper
wire for the primary current and over this several layers of very fine insulated
copper wire for the secondary current, every layer being carefully insulated with
paper dipped into parraffin wax. The said iron core projects on one end of the
said bobbin in front of which I place a spring supported on one end by a suitable
pillar and in the centre of this spring I secure a piece of iron which will be
attracted by the magnetism of the iron core when the current passes through the
primary wire and near the other extreme end of the said spring
place another
pillar furnished with a set screw and lock-nut and which forms the contact breaker.
The last named end of the spring and the point of the set screw are provided with
platinum points to secure always a proper contact.
The said coil and pillars are mounted together on a suitable board on to which
I also fix a switch for the purpose of cutting off the electric circuit from the battery
if placed on one point, to close the circuit again and to put on the primary current
if placed on the second point, and to connect the secondary current if placed on the
third point.
I
This switch is of an improved construction and forms part of my invention.
employ an ordinary switch lever which is supported on one end by a suitable pillar
on which the same is allowed freely to oscillate. The other end of this lever is
provided with a knob or a small handle made of insulating material: underneath
and to the said lever I fix a suitable spring one end of which rests on studs so as
to form a contact either for the primary or the secondary current. Under the said
lever I also mount a second spring which is insulated with or by suitable material
from the first spring. The two ends of this second spring rest and form a contact
upon two metal strips one of which is connected to one of the battery terminals and
the other to the contact breaker or one end of the primary wire of the coil. The
two ends of the last named spring and the two metal strips are so arranged that a
circuit of the current is closed when the switch lever is placed on the studs for the
primary or secondary current but when the said lever is moved to one extreme
end the current from the battery is broken and also from the coil to the
electrodes.
The object of this improvement is to use only one switch lever for breaking or
closing the current and also sending a primary or a secondary current through the
electrodes and bath and thus simplicity is effected and by placing the pillar which
forms the contact breaker at the extreme end of the vibrating spring as afore
described a more regular steady and efficient current such as is required in medical
treatment is produced and
Another of my improvements consists in the application and method of mounting

page_text: the said coil board on to a second board so as to avoid all disarranging of the wires
or other connections when the coil board is to be removed when not in use. The
second board will be a permanent fixture if used for treatment in baths only and is
provided with four suitable terminals and springs, two of which are used for the
connecting wires from the battery and the other two for the connecting wires to the
electrodes. Those springs are so arranged as to clip the coil board and to hold it
firm in its proper position and, at the same time serving as contacts for the current
from the battery to the coil and also from the coil to the electrodes and by this
means the said coil board can be easily removed when not in use and replaced
when required without disturbing any connecting wires.
Dated this 25th day of April 1890.
GUSTAVUS COHEN,
Applicant.
COMPLETE SPECIFICATION.
Improvements in Medical Induction Coils.
I, GUSTAVUS COHEN, of Market Strect, Manchester, in the County of
Lancaster, Medical 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 :-
a
This invention relates to induction coils such as are used for medical purposes
and is designed with the object of providing an induction coil which will produce
more regular steady and efficient current than many of those at present in use and
of providing means for the more easy adjustment or regulation of the current more
especially with reference to electrical baths.
It consists essentially in constructing the apparatus with an armature pivoted or
suspended at one end with the contact making and breaking point at the other:
with a switch provided with two points of contact whereby it can act to connect
either the primary current or the primary and secondary currents to the terminals;
and with a device by which the coil can be readily connected or disconnected with
an ordinary domestic bath.
It will be fully described with reference to the accompanying drawings in which
the several parts of the induction coil are clearly shown.
Fig. 1 is a plan of the apparatus.
Fig. 2 end elevation partly in section.
Fig. 3 plan of the device for connecting the coil with a bath the coil and switch
being removed.
Fig. 4 diagram showing the arrangement for connecting the battery the coil and
the switch.
Q
Fig. 5 elevation of switch and connecting plates M, M'.
Fig. 6 elevation of terminal R¹ and contact piece ¹.
The induction coil A is constructed in the ordinary way with two or more layers
of insulated copper wire wound upon a bobbin of wood or other non-conducting
material, one for the primary and the other for the secondary current-around a
core of soft iron wire B fitted with a loose thin brass tube C which slides over the
core B and inside the bobbin D so as to be easily inserted or withdrawn.
The armature E which forms the contact maker and breaker is attached to the
spring e in the usual way. At one end the spring is permanently attached to the
pillar F by which it is supported and at or near the other extreme end a second
pillar G is placed. The pillar G is furnished with a set screw g and lock nut g
which forms the point of contact with the end of the spring e. The end of the
spring e and the point of the set screw may be provided with platinum points to
always secure a proper contact. By this arrangement of the pillar G and point of
contact with the spring of the armature E at the extreme end the movement of
the spring is lessened it works more steadily and with less noise, and a more
3

page_text: cacy and emcient current such as is required for medical treatment is
produced.
The primary and secondary coils are connected to the terminals by a switch of
novel construction by which with one lever either the primary or primary and
secondary coils are thrown into the circuit. This switch is constructed with a
lever H pivoted on a stud or pillar I upon which it is free to oscillate in either
direction and with which it is in electrical contact and at the other end is provided
with a knob or handle of insulating or non-conducting material. To the lever H
I attach, and in electrical contact with it, a contact making spring J so placed that
as the lever is moved from one side to the other it comes in contact with studs K K¹
and K In addition to the contact maker J I attach to the lever H a second
spring or contact maker L with two contact making points which is insulated by a
block of vulcanite or other material from the lever H. The contact maker L has
two points of contact which are so placed as to engage with two metal strips M, M³,
when the lever H is moved out of contact with the stud K.
Referring more particularly to the diagram Fig. 4 in which the connections or
connecting wires from the different points are shown the poles of the battery are
connected to the terminals Q and R and the handles 0, 0¹ are connected to the
terminals S and T. The terminal R is connected with the pillar F which by means
of the armature E and spring e is connected with the pillar G. To the pillar G is
connected one end of the primary coil V and it is also connected to the terminal T.
The other end of the primary coil is connected with the metallic stud K' which is
connected with the metallic strip M. One end of the secondary coil W is con-
nected at with the end of the primary coil of opposite polarity and the other
end of the secondary coil is connected with the metallic stud K. The metallic
strip M is connected with the battery terminal Q and the pillar or pivot 1 of the
lever His connected with the terminal S. The stud K is insulated and although
I prefer to use it, it may be dispensed with.
When the switch is in the position shown in Fig. 1 the circuit is broken as the
stud K is insulated and the second contact maker L on the lever H is only in contact
with the metallic strip M and no communication between it and the strip M is
established. When the lever H of the switch is moved over the metallic stud K'
the circuit is completed through the primary coil.
The current passes from the terminal R through the armature E and pillar G to
the primary coil and from it to the stud K' and metallic strip M thence through
contact maker L on the lever H through the metallic strip M' to the battery
terminal Q. The primary current to the handles 0 0¹ passes at one side from the
pillar G to the terminal T and at the other from the stud K₁ through the contact
spring J to the lever H and stud pillar I to the terminal S.
When the switch is moved into contact with the metallic stud K" the secondary
coil W is brought into the circuit and the current as before passing through the
primary coil V traverses the secondary coil W which is connected with the stud K¹
and from this it is conveyed through the switch H as above described to terminal S
and handle O.
A tertiary coil may be used and thrown into the circuit in a similar way by the
switch H by using another metallic stud similar to K" and K' to which one end of
the tertiary coil would be connected.
The induction coil, pillars, terminals and switch are all connected to a board A¹
of wood or other insulating or non-conducting material which is of the usual form
or construction.
For application to baths to avoid all disarranging of the wires or other connections
when once connected to the bath I provide a second board A" upon which the
coil board A' is mounted and from which it can be easily removed when not required
for use in connection with the bath. The second board will be made a permanent
fixture and attached to the wall or other convenient place by screws passing through
the holes a. The board A is provided with battery terminals QR₁ and
terminals S T by which it is connected with the bath. To each of these terminals

page_text: are respectively attached metallic spring contact pieces with which
engage the metallic contact pieces 7rst attached to the terminals Q R S T
respectively on the coil board A'. These contact pieces are arranged (preferably
as shown) so as to clip the coil board A¹ and hold it firm in its proper position and
at the same time serve as contacts for the current from the battery to the coil and
from the coil to the electrodes in the bath and by this means the said coil board
can be easily removed when not in use and replaced when required without
disturbing any connecting wires.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. A medical induction coil with the several parts constructed and arranged
substantially as described.
2. A switch for medical induction coils consisting of a pivoted lever (H) carrying
a contact maker J and an insulated contact maker L in combination with a series
of studs (KK' K") insulated from each other but connected with the different
currents, through which the circuit is closed by the contact maker J, and with
the metallic strips M M through which the circuit is closed by the contact
maker L, substantially as and for the purpose described.
3. A switch for medical induction coils constructed, arranged and connected
substantially as described and shown.
4. The combination with a medical induction coil of a second board to be made
a permanent fixture to which the coil can be readily attached and connected by
means of spring contact pieces and from which it can be easily removed without
moving the connections substantially as described and shown.
Dated this 17th day of January 1891.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.