An Improved Make-and-break for Induction Coils and the like.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improved Make-and-break for Induction Coils and the like.
We, JAMES KING, of 12 Bousfield Road, Nunhead, S.E., Gentleman, and CHARLES
HENRY WATSON, of 313 High Holborn, W.C., Optician, do hereby declare the
nature of this Invention to be as follows:-
This Invention relates to an improved vibrating interrupter or make-and-break
for the primary circuit of an induction coil and the like, and has for its object to
enable the period of make-and-break to be more efficiently controlled, to obtain a
more sudden interruption and a more prolonged closure of the primary circuit
and thereby to enable an equally high inductive efficiency to be obtained with less
generating power and consequently less sparking and heating effect at the contacts.
The back contact is formed by an adjusting screw mounted in a fixed post, but
instead of the front contact being carried by the vibrating hammer it is carried
by a flat spring similar to that of the hammer and situated between the hammer
and the back contact, the primary winding of the coil being connected to this inter-
mediate contact spring instead of to the hammer spring. The head of the contact
spring is situated within the embrace of a bracket or yoke carried upon the head
of the hammer spring so that the hammer spring is capable of a certain amplitude
of vibration under the magnetic pull of the core independently of the contact
spring, the amplitude of this independent vibration being determined by an
adjusting screw mounted in the bracket in position to bear against the contact
spring when by the magnetic pull of the core on the hammer the limit of its
independent vibration is exceeded. This happens when the hammer is at about
the middle of its forward vibration and is consequently moving at about its
highest velocity the effect of the hammer then striking the contact spring being
to cause an instantaneous rupture of the circuit. The rigidity of the contact spring,
and consequently the stress with which its contact bears against the back contact,
is regulated by another adjusting screw.
By this independence of the hammer the amplitude of its vibration is not
checked by the one contact suddenly striking against the other, the hammer on
its backward motion vibrating independently and completing its vibration un-
checked except by its own spring and by the magnetic attraction of the core, whilst
the spring contact remains at rest against the other, so that during this independent
vibration of the hammer there is a prolonged period of contact which gives the
necessary time for the thorough magnetic saturation of the core, thus greatly
reducing the generating power required without lessening the efficiency of the coil.
Dated this 8th day of April 1897.
A. M. & WM. CLARK,
Chartered Patent Agents, 53 Chancery Lane, London.

page_text: An Improved Make-and-break for Induction Coils and the like.
We, JAMES KING, of 12 Bousfield Road, Nunhead, S.E., Gentleman, and CHARLES
HENRY WATSON, of 313 High Holborn, W.C., Optician, 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 an improved vibrating interrupter or make-and-break
for the primary circuit of an induction coil and the like, and has for its object to
enable the period of make-and-break to be more efficiently controlled, to obtain a
more sudden interruption, and a more prolonged closure of the primary circuit
and thereby to enable an equally high inductive efficiency to be obtained with less
generating power and consequently less sparking and heating effect at the contacts.
Reference is to be had to the accompanying drawing forming part of this Specifi-
cation, which illustrates the interrupter in elevation in Figures 1 and 2 in the two
extreme positions of its vibration.
The back contact a is carried as usual by an adjusting screw mounted in a
post b but instead of the front contact c being carried by the vibrating hammer
spring d¹ it is carried by an intermediate spring e through which the primary
winding of the coil is connected to the contact c (instead of through the hammer
spring d) the post 6 being connected with one of the terminals of the instrument
as usual. The upper end e¹ of the contact spring is situated within the embrace
of a bracket or yoke f carried upon the vibrating hammer spring d' so that the
latter may vibrate, to a certain extent, independently of the contact spring c.
extent of this independent vibration of the hammer is represented in Figure 1 by
the space between the spring e and an adjusting screw f¹ mounted in the bracket f
in position to strike against the upper end e¹ of the contact spring e. This happens
The
when the hammer is at about the middle of its forward vibration and is conse-
quently moving at about its highest velocity, the effect of the sudden blow against
the contact spring being to cause an instantaneous rupture of the circuit, between
contacts a and c. The vibrating hammer may be provided with an arm h carrying
an adjustable weight h¹ whereby to regulate the period of vibration of the hammer
(but this in itself forms no part of the invention) whilst the strength of the contact
spring e is regulated by another adjusting screw g screwing into a post g² and
having a shoulder g¹ which bears against the spring e, the screw being insulated
from post b.
The hammer being thus independent of the contact c during the latter part of its
backward motion, the amplitude of the vibration of the hammer is not checked by:
the contact c suddenly striking against the contact a, the hammer completing its
vibration checked only by its own spring and by the magnetic attraction of the
core whilst the contact c remains at rest against the contact a so that during this
independent vibration of the hammer there is a prolonged period of contact
between c and a which gives the necessary time for the thorough magnetic satura-
tion of the core.
It will be evident that the yoke f might be carried by the spring e and the
hammer play within it or be otherwise arranged so as to permit the partial inde-
pendent vibration of the hammer and the periodical and sudden connection of the
hammer with the contact spring e.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the the same is to be performed we declare that what
we claim is: -
1. In the interrupter of an induction coil the combination with the vihratine

page_text: and stationary primary-circuit breaking contacts, of a hammer adapted to vibrate
independently of the vibrating contact and to act thereon towards the middle of
its vibration so as to suddenly separate it from the stationary contact and produce
a sudden interruption of the circuit substantially as specified.
2. The herein described interrupter of an induction coil consisting in the com-
bination, with a vibrating hammer adapted to be vibrated under the influence of
the magnetic pull of the coil and of its spring, and with a stationary back contact,
of a movable contact carried by a spring and adapted to make contact with the
stationary contact, adjustable means whereby the hammer is permitted to vibrate
independently of the movable contact during a portion of its swing and is caused to
act thereon towards the middle of its swing so as to suddenly separate the movable
from the stationary contact, and means of adjusting the vibration of the movable
contact independently of the vibrating hammer substantially as specified.
3. The herein described improved primary circuit breaker or interrupter for
au induction coil constructed to operate substantially as specified.
Date : 6th low of Thamber 1907
A. M. & WM. CLARK,
Chartered Patent Agents, 53 Chancery Lane, London.