Year: 1899

page_text: We, HARRY PHILLIPS DAVIS, of 327, Neville Street, Pittsburgh, and GILBERT
WRIGHT, of 409, Ross Avenue, Wilkinsburg, both in the County of Allegheny
and State of Pennsylvania, U.S.A., Electrical Engineers, do hereby declare
the nature of this invention to be as follows:-
:-
Our invention relates to circuit breakers which act to break the circuit when
the current exceeds a certain amount.
Our improved circuit breaker is more especially intended for use on high
tension circuits, being provided with contacts of carbon or the like shunting the
main contacts at which the circuit is finally broken and provision being made
for insuring that a considerable gap shall be formed between the terminals of
the breaker when it has been operated to interrupt the circuit.
The special feature of our invention consists in an arrangement whereby
before the infusible shunt contacts are separated the movable contact is caused
to slide on the fixed' contact so that the engaging faces are maintained clean
and a good contact is made between them. The invention comprises various
details of construction as hereinafter set forth. In the drawings Figure 1 is
a side elevation, parts being broken away, and Figure 2 is a plan view of the
instrument looking upward.
1 is the base to which is secured an arm 3 supporting the fixed terminal 2.
Said terminal carries an infusible block 5 and a main laminated contact 4.
The movable terminals are indicated at 6 and 7, being carried on the end of
an arm 8 and connected by a flexible lead 9 to the other fixed terminal of the
circuit. The arm 8 is pivoted at 14 between two substantially triangular-
shaped plates 121, which are carried by a sleeve 12 pivoted on a pin 11 to
brackets 10 secured to the base. The sleeve 12 has a rearwardly projecting
portion 122, the shape of which is best seen from Figure 1, and which is con-
nected on the one hand by a spring 29 to a bracket 30 secured to the base 1,
and on the other hand by a spring 28 to the arm 8 at a point some distance
above its pivot.
Loosely mounted upon a rod 19 secured to brackets 10 attached to the base
is a sleeve 171 having projecting arms 17 connected through toggle links 16
to a pivot 15 joining the lower corners of the triangular plates 121. The end
of the arm 20 is provided with a roller 201 which can engage with a latch 21

page_text: a
operated through a projection 22 with which a tripping projection 23 on
rod 24 attached to the core 25 of the operating solenoid 20 can engage. The
rod 24 is provided with an adjustable weight 27 so that the movement of the
core 25 can be caused to take place when any desired strength of current is
passing through the solenoid 20. It will be seen that when the core of said
solenoid is moved upwards through the action of the current flowing in the
solenoid 26 to a sufficient distance to cause the projection 23 to strike the
arm 22, the latch 21 will be disengaged from the roller on the end of the
lever 20 so that said lever is free to move downward. This downward movement
of the lever 20 is caused by an upward movement of the toggle levers 16, 17,
which is due to the pull of the spring. 29 acting upon the part 122 so as to
rotate the sleeve 12 on its pin 11 carrying with it the triangular pieces 121.
During the first part of this movement the spring 28 will maintain the movable
contact 7 pressed against the fixed contact 5 and the effect will therefore be
that the arm 8 moves downward as a whole until it reaches the position shewn
in dotted lines in Figure 1, in which the main contacts 4 and 6 are separated
while the shunt contacts 5 and 7 are still connected. This position lasts only
for a short time since the spring 29 ultimately causes the whole mechanism
to rotate round the pin 11 and thereby throw the arm 8 outward and separate
both main and shunt terminals to a considerable distance. The movement is
ultimately limited by the stretching of the springs 28, 29, which thereby pre-
vents any jarring or shock to the parts.
\
In order to close the breaker we provide arms 31, pivoted at 19, to the
brackets 10, the upper end of one of said arms being connected by a spring 35
to the base 1. If after the circuit breaker has been opened in the manner pre-
viously described the arms 31 are moved to the position shewn in dotted lines
in Figure 1 against the pull of the spring 35, projections 33 on said arms
engage with the arms 17 and move them downward causing through the agency
of the links 16 the triangular pieces 121 to rotate round the pivot 11 in the
upward direction, and thereby bring the infusible contacts 7 and 5 into con-
nection. Further pressure on the arms 17 by means of the levers 31 will
result in a further rotation of the parts 121 which will force the arm 8 in an
upward direction against the pull of the spring 28 until the main contacts 6
and 4 make connection. During this last portion of the operation the contact 7
will slide on the face of the contact 5 thereby ensuring the keeping of the
engaging faces clean and the making of a good contact between them. At the
end of the movement when the breaker is closed stops 161,on the toggle links 16
engage with a stop 34 on the brackets 10 so as to prevent the toggle mechanism
being moved too far by pressure of the handle; the roller 201 at the end of the
arm 20 also engages with the notch in the latch 21 and so holds the breaker
closed.
While we have shewn and described specific mechanism for carrying out our
invention is obvious that the details of construction may be considerably
varied and we are not limited to the precise details shewn and described.
Dat
the 1041 law of T.... 1900
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.

page_text: and State of Pennsylvania, U.S.A., Electrical Engineers, 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:-
Our invention relates to circuit breakers which act to break the circuit when
the current exceeds a certain amount.
Our improved circuit breaker is more especially intended for use on high
tension circuits, being provided with contacts of carbon or the like shunting the
main contacts at which the circuit is finally broken and provision being made
for insuring that a considerable gap shall be formed between the terminals of
the breaker when it has been operated to interrupt the circuit.
The special feature of our invention consists in an arrangement whereby
before the infusible shunt contacts are separated the movable contact is caused
to slide on the fixed contact so that the engaging faces are maintained clean
and a good contact is made between them. The invention comprises various
details of construction as hereinafter set forth. In the drawings accompanying
the Provisional Specification Figure 1 is a side elevation, parts being broken
away, and Figure 2 is a plan view of the instrument looking upward.
1 is the base to which is secured an arm 3 supporting the fixed terminal 2.
Said terminal carries an infusible block 5 and a main laminated contact 4.
The movable terminals are indicated at 6 and 7, being carried on the end of
an arm 8 and connected by a flexible lead 9 to the other fixed terminal of the
circuit. The arm 8 is pivoted at 14 between two substantially triangular-
shaped plates 121, which are carried by a sleeve 12 pivoted on a pin 11 to
brackets 10 secured to the base. The sleeve 12 has a rearwardly projecting
portion 122, the shape. of which is best seen from Figure 1, and which is con-
nected on the one hand by a spring 29 to a bracket 30 secured to the base 1,
and on the other hand by a spring 28 to the arm 8 at a point some distance
above its pivot.
Loosely mounted upon a rod 19 secured to brackets 10 attached to the base
is a sleeve 171 having projecting arms 17 connected through toggle links 16
to a pivot 15 joining the lower corners of the triangular plates 121. The end
of the arm 20 is provided with a roller 201 which can engage with a latch 21
operated through a projection 22 with which a tripping projection 23 on a
rod 24 attached to the core 25 of the operating solenoid 26 can engage. The
rod 24 is provided with an adjustable, weight 27 so that the movement of the
core 25 can be caused to take place when any desired strength of current is
passing through the solenoid 26. It will be seen that when the core of said
solenoid is moved upwards through the action of the current flowing in the
solenoid 26 to a sufficient distance to cause the projection 23 to strike the
arm 22, the latch 21 will be disengaged from the roller on the end of the
lever 20 so that said lever is free to move downward. This downward movement
of the lever 20 is caused by an upward movement of the toggle levers 16, 17,
which is due to the pull of the spring 29 acting upon the part 122 so as to
rotate the sleeve 12 on its pin 11 carrying with it the triangular pieces 121.
During the first part of this movement the spring 28 will maintain the movable
contact 7 pressed against the fixed contact 5 and the effect will therefore be
that the arm 8 moves downward as a whole until it reaches the position shewn
in dotted lines in Figure 1, in which the main contacts 4 and 6 are separated
while the shunt contacts 5 and 7 are still connected. This position lasts only
for a short time since the spring 29 ultimately causes the whole mechanism
to rotate round the pin 11 and thereby throw the arm 8 outward and separate
both main and shunt terminals to a considerable distance. The movement is
ultimately limited by the stretching of the springs 28, 29, which thereby pre-
vents any jarring or shock to the parts.
In order to close the breaker we provide arms 31, pivoted at 19, to the
brackets 10, the upper end of one of said arms being connected by a spring 35

page_text: to the base 1. If after the circuit breaker has been opened in the manner pre-
viously described the arms 31 are moved to the position shewn in dotted lines
in Figure 1 against the pull of the spring 35, projections 33 on said arms
engage with the arms 17 and move them downward causing through the agency
of the links 16 the triangular pieces 121 to rotate round the pivot 11 in the
upward direction, and thereby bring the infusible contacts 7 and 5 into con-
nection. Further pressure on the arms 17 by means of the levers 31 will
result in a further rotation of the parts 121 which will force the arm 8 in an
upward direction against the pull of the spring 28 until the main contacts 6
and 4 make connection. During this last portion of the operation the contact 7
will slide on the face of the contact 5 thereby ensuring the keeping of the
engaging faces clean and the making of a good contact between them. At the
end of the movement when the breaker is closed stops 161 on the toggle links 16
engage with a stop 34 on the brackets 10 so as to prevent the toggle mechanism
being moved too far by pressure of the handle; the roller 201 at the end of the
arm 20 also engages with the notch in the latch 21 and so holds the breaker
closed.
While we have shewn and described specific mechanism for carrying out our
invention it is obvious that the details of construction may be considerably
varied and we are not limited to the precise details shewn and described.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. An automatic circuit breaker in which the movable main and shunt ter-
minals are carried by an arm hinged to a frame which frame is itself pivoted
to a fixed support, substantially as and for the purpose specified.
2. An automatic circuit breaker in which the supporting arm for the moving
terminals is hinged to one side of a frame and connected through a spring to
the other side of the frame, said frame being pivoted to fixed brackets and con-
nected by toggle levers to an electro-magnetic releasing device, substantially
as described.
3. An automatic circuit breaker constructed and operating as described and
shewn in the drawings accompanying the Provisional Specification.
Dated the 18th day of April 1900.
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.