Improvements in Contact Breakers for the Firing Devices of Internal Combustion Engines.
Year: 1899

page_text: Date of Application, 14th Apr., 1899
Complete Specification Left, 27th Dec,, 1899-Accepted, 3rd Feb., 1900
PROVISIONAL SPECIFICATION.
Improvements in Contact Breakers for the Firing Devices of Internal
Combustion Engines.
I, CHARLES THOMAS BROCK SANGSTER, General Manager to The Cycle Com-
ponents Manufacturing Company, Limited, of Bournbrook, near the City of
Birmingham, do hereby declare the nature of this invention to be as follows:-
This invention has relation to contact breakers or contact makers used in
connection with the sparking devices of internal combustion engines for making
and breaking contact or for completing the electrical circuit to admit of the
passage of an electric spark for firing the charge of explosive mixture contained
within the motor cylinder at a predetermined period during the compression
stroke of the piston.
It has heretofore been the practise to complete the firing circuit by means of a
vibrator or spring arm connected with one wire of the circuit and provided
with a platinum piece for making contact with the terminal of the other
circuit wire, said vibrator having at the free end a wiper acting in conjunction
with a rotating cam on the valve shaft or other auxiliary shaft of the motor.
This cam has a notch or depression in its periphery into which the wiper end of the
vibrator drops at the time when the sparking is to occur, thus allowing the
platinum piece to contact with the opposite terminal of the circuit and admitting
the current to pass, but in consequence of the spring arm being free or unrestrained
and unprovided with any device for compelling it to make a positive contact other
than by its own spring construction, it frequently occurs that the efficient action
of the device is prevented by the vibration attendant upon the running of the
motor, hence mis-fires through imperfect contact.
The object of my invention is to provide a positive contact device, and this I
propose to obtain by the employment in conjunction with the vibrator or contact
arm, of a rotating cam on the valve gear shaft or other auxiliary spindle, provided
with a lift or projection which is timed to come behind the vibrator and thrust
it into positive contact with its opposite terminal at the moment when the circuit
is to be completed for firing.
In carrying out my invention, one end of the vibrator is connected as usual to
a suitable circuit terminal fitted to an adjustable insulating base board and is
provided at a suitable part of one side with a platinum piece adapted to contact
with an opposed circuit terminal also fitted to the said base but disposed on the
opposite side of the vibrator or spring arm to that on which the cam comes. This
cam is keyed to a shaft controlled by the two-to-one valve gearing of the motor
and the greater part or some two-thirds of its periphery is plain, whilst the other
part is in the form of a gradual rise or lift terminating in a sudden drop to the rest
part of the cam. The wiper at the free end of the vibrator (which is disposed
between the cam and the circuit terminal with which it is to contact) rests on the
periphery of the cam and is forced outwards by the lift or rise of the said cam
so as to bring the platinum piece thereof into positive contact with the terminal

page_text: at the moment when the circuit is to be completed, whilst the sudden drop in
the cam provides for a quick break action by allowing the vibrator to spring back
out of contact.
The insulating base upon which the terminals and vibrator is mounted is
adjustable around the cam shaft to admit of the relative positions of the vibrator
and cam being altered to vary the moment of sparking.
ן:
1000
Improvements in Contact Breakers for the Firing Devices of Internal
Combustion Engines.
I, CHARLES THOMAS BROCK SANGSTER, General Manager to The Cycle Com-
ponents Manufacturing Company, Limited, of Bournbrook, near the City of
Birmingham, 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 has relation to the ignition devices used in connection with
internal combustion engines of the De Dion or similar types, in which a vibrating
contact blade is used for making and breaking contact to admit of the passage
of a series of electric sparks for firing the charge of explosive mixture contained
within the motor cylinder at a predetermined period during the compression stroke
of the piston.
It has heretofore been the practise to produce the necessary interruptions in
the current for obtaining a series of ignition sparks either magnetically through
the medium of the trembler of an induction coil, or else by means of a spring
arm connected with one wire of the circuit provided with a platinum piece
for making contact with the terminal of the other circuit wire, said vibrator
having at the free end a wiper acting in conjunction with a rotating cam on the
valve shaft or other auxiliary shaft of the motor. This cam has a notch or
depression in its periphery into which the wiper end of the vibrator drops at the
time when the sparking is to occur, thus allowing the platinum piece to contact
with the opposite terminal of the circuit and permit the current to pass, but in
consequence of the spring arm being free or unrestrained and unprovided with any
device for compelling it to make a positive contact other than by its own spring
construction, it frequently occurs that the efficient action of the device is prevented
by the vibration attendant upon the running of the motor, hence mis-fires through
imperfect contact.
a
The object of my invention is to provide a positive contact device, and this I
propose to obtain by the employment in conjunction with the vibrator or contact
arm, of a rotating cam on the valve gear shaft or other auxiliary spindle, provided
with a lift or projection which is timed to come behind the vibrator and thrust
it into positive contact with its opposite terminal at the moment when the circuit
is to be completed for firing.
Figure 1 represents a perspective view and Figure 2 a front elevation upon a
breaking contact to produce the necessary current interruptions, constructed and
arranged according to my invention.
In carrying out this form of my invention, one end a¹, of the vibrator a is
connected as usual to a suitable circuit terminal fitted to an ebonite rocker or

page_text: other adjustable insulating base c, and is adapted at a suitable part of one side
to contact with the platinum point ², of a screw d carried by the opposed circuit
terminal d, which is also fitted to the said base but is disposed on the opposite
side of the vibrator or spring arm to that on which the cam e comes. This cam
is keyed to a shaft el, controlled by the two-to-one valve gearing of the motor or
by a suitably driven independent spindle, and the greater part or some two-
thirds of its periphery e², is plain, whilst the other part is in the form of a
gradual rise or lift et, terminating in a sharp drop e, to the rest part of the
cam. A wedge shaped steel wiper or nose a² to the rest or lift is provided at the
free end of the vibrator (which is disposed between the cam and the circuit
terminal with which it is to contact) and rests on the periphery of the cam and
is forced outwards by the lift or rise of the said cam so as to bring it into
positive contact with the platinum point of the terminal d, at the moment when
the circuit is to be completed whilst the sudden drop in the cam provides for a
quick break action by allowing the vibrator to spring back out of contact.
The insulating base upon which the terminals and vibrator are mounted is.
adjustable around the cam shaft to admit of the relative positions of the vibrator
and cam being altered to vary the moment of sparking.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is: :-
In the electric ignition devices of internal combustion engines, the employment
in conjunction with a contact blade or spring arm, such as, connected with the
one terminal of the ignition circuit, of a rotating cam such as e, worked by the
motor and adapted to thrust the said arm into contact with the second circuit
terminal, substantially as and for the purpose herein described, and also as set
forth in the accompanying drawings.