ACC Circuit Breakers.
Year: 1899

page_text: Date of Application (in United Kingdom), 22nd July, 1899
Complete Specification Left, 18th Apr., 1900-Accepted, 23rd June 1900
ACC Circuit Breakers.
We, GILBERT WRIGHT, of 409, Ross Avenue, and CHRISTIAN AALBORG, of
212, Franklin Street, both of Wilkinsburg, 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 by means of which the electric circuit
will be automatically opened when the current therein exceeds a predetermined
amount.
The invention consists in a circuit breaker having a toggle lever mechanism
with an electromagnetic device for operating same to open the circuit, and it
possesses as its characteristic feature a special arrangement of the movable
shunt contact which when the circuit is opened is tilted so that its upper edge
slides along the face of the fixed shunt contact the circuit being finally broken
at said upper edge.
The invention will be understood from the accompanying drawings which
illustrate a practical embodiment of our invention.
Figure 1 is a side elevation, and
Figure 2 is a detail sectional view of a portion of the circuit breaker when
closed.
Figure 3 is a side elevation of the breaker when the circuit is open, parts of
the device being removed and others shewn in section.
Figure 4 is a front elevation of the device drawn to a reduced scale.
1 is a non-conducting base on which are mounted the stationary terminals 2
and 3 to which the circuit conductors are connected. The terminal 2 has an
upward extension 4 in which is mounted a block 5 of carbon, the lower ter-
minal 3 is partly surrounded by a piece of iron 6 which may be laminated when
he circuit breaker is to be used for alternating currents and roughly forms a
horse-shoe. The armature 7, of the electro-magnet formed by the piece of iron 6
s supported on a frame 8 which is pivoted at 9 to brackets 10 secured to the
ase 1. The frame 8 is provided with an adjustable weight 11 so that the
breaker may be set to operate at any said desired strength of current.
The main movable portion of the circuit breaker comprises a bundle of curved
aminæ 12 which are rivetted to an arm 13 which is also pivoted at 9 to the
rackets 10. The main movable member is furthermore provided with a spring
Price 77

page_text: plate 14 which extends downward at the back to such a length and is of such
a form that it makes contact at all times with the face of the terminal 3 and
owing to its resiliency its upper end will break contact with the terminal 2
after the main contact has been ruptured. The movable shunt contact proper
is a block of carbon 15 pivoted to an arm 16 which is itself-pivoted at 17 to
the frame 13, the lower end of said arm being connected through a spring 18
to the handle 19 of the circuit breaker. A spring 20 attached to the socket of
the carbon contact 15 causes the upper end of said contact to normally tilt
toward the fixed shunt contact 5. The handle 19 is pivoted at 21 to the
brackets 10 and connected to a toggle lever 22 with the frame 13 which supports
the movable member of the breaker. Said toggle lever 22 has a projection in
which is mounted a roller 23 which engages the notched end of a latch 24
pivoted on the pivot 9. The latch is adapted to engage with two projections 25
and 26 secured to the frame 8 the latter of which terminates adjacent to the
latch above its pivot 9 and the other adjacent to the lower end of the latch,
this is clearly shewn in Figure 3. These projections 25 and 26 are of such
length that the frame 8 can move to a small extent on its pivot independently
of the latch 24 in order that the latter may be given a blow when the frame is
tilted at the attraction of the armature 7. In order to move the frame manu-
ally when desired we provide the rod 27 which projects through the base 1, the
end of said rod being secured to a pivoted lever 28 the other end of which can
be moved by means of a handle 29 normally pressed outward by a spring 30 or
other suitable device. It is clear that pressure on the handle 29 will through
the link-work cause the frame S to rotate on its pivot 9 in the same manner
as if the armature 7 were attracted by the magnetic portion 6. The frame 13
is provided with a pin 31 pressed outward by means of a spring 32 so as to
form a kind of buffer which when the circuit breaker is open falls against a
projection 33 from the lever 19 so as to prevent the movable parts of the circuit
breaker being injured by a sudden jar.
The operation of this device is as follows:-
-
Assuming that the breaker is in the open position shewn in Figure 3 a down-
ward pressure on the outer end of the lever 19 will cause the toggle joint to
move upward carrying the movable member 12 towards the stationary ter-
minals 2 and 3 together with the arm 16 and with the shunt contact 15. The
movement is continued until the pivots of the toggle link 22 are brought nearly
into alignment with the pivot 21 in which position the weight of the frame 8
will through the projection 25 cause the latch 24 to turn on its pivot 9 and the
notched end thereof to engage with the roller 23 secured to the link 22. This
position of the parts is shewn very clearly in Figure 2, the movable contact 12
being pressed tightly against the fixed contacts 2 and 3. It will be observed
that while the breaker is being closed the pressure of the lever 19 will through
the medium of the spring 18 rotate the arm 16 on its pivot 17 so that the upper
edge of the carbon contact 15 will first touch the fixed contact 5 and then as
the closing movement is continued the carbon contact 15 will slide upon the
fixed contacts 5 until the breaker is quite closed when the faces of the con-
tacts 15 and 5 will be closely pressed together. The extent of this sliding
movement can be seen from the dotted lines in Figure 3 which shew various
positions of the movable shunt contact 15.
The opening of the circuit which is effected when the armature 7 is attracted,
takes place in the following manner:
-
The movement of the frame 8 on the pivot 9 causes the projection 26 to
strike the latch 24 and thereby withdraw its notched end from engagement
with roller 23 whereupon the spring or springs 18 will throw the toggle joint
downward and supplemented by the action of gravity will throw the circuit
breaker completely open to the position shewn in Figure 3. The spring pin 31
engaging with the projection 33 prevents the mechanism receiving any sudden
jar or shock.
The movable main member 12 will obviously first leave the ter-

page_text: minal 2 and the current will be shunted through the strip 14 and carbon con-
tacts 15, 5. As the opening movement continues the carbon contact 15 will first
slide down the face of the contact 5 rotating on its pivot meanwhile, and finally
the circuit will be broken at the upper edge of said carbon contact 15 as indi-
cated in the lower position shewn in dotted lines in Figure 3. By reason of
interrupting the circuit at a single point making a single break and locating
that break above the main terminals the resulting are cannot by any possibility
do any damage to the circuit breaker it being broken upward at a single point
and away from all of the metal parts of the device. In order that the opera-
tion of the breaker to open the circuit shall occur quickly as soon as the
latch 24 releases the roller 23 the length of the toggle levers are so arranged
that when the circuit breaker is closed the pivot joining the link 22 to the
lever 19 is below the line joining the pivot of said toggle lever to the frame-
work 13 and the pivot 22. "The locking of the device in the closed position is
ensured by the engagement of the latch 24 and roller 23.
Dated the 22nd day of July 1899.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.
We, GILBERT WRIGHT, of 409, Ross Avenue, and CHRISTIAN AALBORG, of
212, Franklin Street, both of Wilkinsburg, in the County of Allegheny 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 by means of which the electric circuit
will be automatically opened when the current therein exceeds a predetermined
amount.
The invention consists in an automatic circuit breaker having main and shunt
contacts in vertical alignment and characterized by the movable shunt contact
being so arranged that it first slides down and then its under part tilts away from
the fixed contact during the operation of opening the circuit so that the final
interruption occurs at the upper edge of said movable contact.
In the drawings filed with the Provisional Specification illustrating a practical
embodiment of our invention
.
Figure 1 is a side elevation, and
Figure 2 is a detail sectional view of a portion of the circuit breaker when
closed.
Figure 3 is a side elevation of the breaker when the circuit is open, parts of
the device being removed and others shewn in section.
Figure 4 is a front elevation of the device drawn to a reduced scale.
1 is a non-conducting base on which are mounted the stationary terminals 2
and 3 to which the circuit conductors are connected. The terminal 2 has an
upward extension .4 in which is mounted a block 5 of carbon, the lower ter-
minal 3 is partly surrounded by a piece of iron 6 which may be laminated when
the circuit breaker is to be used for alternating currents and roughly forms a
horse-shoe. The armature 7 of the electro-magnet formed by the piece of iron 6
is supported on a frame 8 which is pivoted at 9 to brackets 10 secured to the
base 1. The frame 8 is provided with an adjustable weight 11 so that the
breaker may be set to operate at any said desired strength of current.

page_text: The main movable portion of the circuit breaker comprises a bundle of curved
laminæ 12 which are riveted to an arm 13 which is also pivoted at 9 to the
brackets 10. The main movable member is furthermore provided with a spring
plate 14 which extends downward at the back to such a length and is of such
a form that it makes contact at all times with the face of the terminal 3 and
owing to its resiliency its upper end will break contact with the terminal 2
after the main contact has been ruptured. The movable shunt contact proper
is a block of carbon 15 pivoted to an arm 16 which is itself pivoted at 17 to
the frame 13, the lower end of said arm being connected through a spring 18
to the handle 19 of the circuit breaker. A spring 20. attached to the socket of
the carbon contact 15 causes the upper end of said contact to normally tilt toward
the fixed shunt contact 5. The handle 19 is pivoted at 21 to the brackets 10
and connected through a toggle lever 22 with the frame 13 which supports
the movable member of the breaker. Said toggle lever 22 has a projection in
which is mounted a roller 23 which engages the notched end of a latch 24
pivoted on the pivot 9. The latch is adapted to engage with two projections 25
and 20 secured to the frame 8 the latter of which terminates adjacent to the
latch above its pivot 9 and the other adjacent to the lower end of the latch,
this is clearly shewn in Figure 3. These projections 25 and 26 are of such
length that the frame 8 can move to a small extent on its pivot independently
of the latch 24 in order that the latter may be given a blow when the frame is
tilted at the attraction of the armature 7. In order to move the frame manu-
ally when desired we provide the rod 27 which projects through the base 1, the
end of said rod being secured to a pivoted lever 28 the other end of which can
be moved by means of a handle 29 normally pressed outward by a spring 30 or
other suitable device. It is clear that pressure on the handle 29 will through
the link-work cause the frame 8 to rotate on its pivot 9 in the same manner
as if the armature 7 were attracted by the magnetic portion 6. The frame 13
is provided with a pin 31 pressed outward by means of a spring 32 so as to
form a kind of buffer which when the circuit breaker is open falls against a
projection 33 from the lever 19 so as to prevent the movable parts of the circuit
breaker being injured by a sudden jar.
The operation of this device is as follows:-
Assuming that the breaker is in the open position shewn in Figure 3 a down-
ward pressure on the outer end of the lever 19 will cause the toggle joint to
move upward carrying the movable member 12 towards the stationary ter-
minals 2 and 3 together with the arm 16 and with the shunt contact 15. The
movement is continued until the pivots of the toggle link 22 are brought nearly
into alignment with the pivot 21 in which position the weight of the frame 8
will through the projection 25 cause the latch 24 to turn on its pivot 9 and the
notched end thereof to engage with roller 23 secured to the link 22. This
position of the parts is shewn very clearly in Figure 2, the movable contact 12
being pressed tightly against the fixed contacts 2 and 3. It will be observed
that while the breaker is being closed the pressure of the lever 19 will through
the medium of the spring 18 rotate the arm 16 on its pivot 17 so that the upper
edge of the carbon contact 15 will first touch the fixed contact 5 and then as
the closing movement is continued the carbon contact 15 will slide upon the
fixed contact 5 until the breaker is quite closed when the faces of the con-
tacts 15 and 5 will be closely pressed together. The extent of this sliding
movement can be seen from the dotted lines. in Figure 3 which shew various
positions of the movable shunt contact 15.
The opening of the circuit which is effected when the armature 7 is attracted,
takes place in the following manner :-
The movement of the frame 8 on the pivot 9 causes the projection 26 to
strike the latch 24 and thereby withdraw its notched end from engagement
with roller 23 whereupon the spring or springs 18 will throw the toggle joint
downward and supplemented by the action of gravity will throw the circuit

page_text: breaker completely open to the position shewn in Figure 3. The spring.pin 31
engaging with the projection 35 prevents the mechanism receiving any sudden
jar or snock. The movable main member 12 will obviously first leave the ter-
minal 2 and the current will be shunted through the strip 14 and carbon con-
tacts 15, 5. As the opening movement continues the carbon contact 15 will first
slide down the face of the contact 5 rotating on its pivot meanwhile, and finally
the circuit will be broken at the upper edge of said carbon contact 15 as indi-
cated in the lower position shewn in dotted lines in Figure 3. By reason of
interrupting the circuit at a single point, making a single break and locating
that break above the main terminals the resulting are cannot by any possibility
do any damage to the circuit breaker it being broken upward at a single point
and away from all of the metal parts of the device. In order that the opera-
tion of the breaker to open the circuit shall occur quickly as soon as
latch 24 releases the roller 23 the length of the toggle levers are so arranged
that when. the circuit breaker is closed the pivot joining the link 22 to the
lever 19 is below the line joining the pivot of said toggle lever to the frame-
work 13 and the pivot 22. The locking of the device in the closed position is
ensured by the engagement of the latch 24 and reller 23.
the
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 having main and shunt contacts the latter
being so arranged that the movable contact first slides down and then tilts away
from the fixed contact during the operation of opening the circuit so that the
final interruption occurs at the edge of the movable contact.
2. A circuit breaker constructed and operating substantially as described
with reference to the accompanying drawings.
Dated the 18th day of April 1900'
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester and Birmingham.