Improvements in
Year: 1899

page_text: Improvements in
I, GILBERT WRIGHT, of 409, Ross Avenue, Wilkinsburg, in the County of
Allegheny, State of Pennsylvania, United States of America, Electrical Engineer,
do hereby declare the nature of this invention to be as follows:-
My invention relates to circuit breakers by means of which the circuit is
automatically opened when the current therein exceeds a pre-determined
amount.
The invention consists in a circuit breaker with a toggle lever mechanism for
locking the breaker in the position in which the circuit is closed and having an
electro-magnetic device for operating the mechanism to open the circuit. In
order that the mechanism shall be easily operated to open and close the circuit
as to reduce the
the toggle levers are provided with knife edge bearings so
friction.
In the accompanying drawings-
Figure 1 is a side elevation, and
Figure 2 a front elevation of one form of my improved circuit breaker shewn
in the closed position.
Figure 3, 4 and 5 are perspective views of the pivots shewing the knife edges,
and
Figure 6 is a front view shewing the electromagnetic releasing device.
Figure 7 is an under plan view of another form, and
Figure 8 is a transverse section of the device shewn in Figure 7.
1 is a non-conducting base upon which. are mounted the stationary terminals 2
The terminal 2 has an
and 3 to which the circuit conductors are connected.
upward extension 5 carrying a socket 6 in which is mounted a block of carbon.
The lower terminal 3 is partially surrounded by a piece of iron 8 which may
be laminated when the current breaker is to be used for alternating currents
and roughly forms a horseshoe (see Figure 6). The armature 9 of the electro-
magnet 8 is supported on arms 10 pivoted at 101 to the brackets 11 secured to
the base 1 and said arms are joined by a transverse bar 12 so as to form a fork
as will be readily seen from Figure 2 and carry an adjustable weight 14.

page_text: The main movable portion of the circuit breaker comprises a bundle of curved
laminae 17 which are rivetted to an arm 18 pivoted at 181 in the brackets 11.
For the purpose of affording a final contact with the terminal 2 after the main
portion of the part 17 has left such terminal, the block 19 mounted on the
spring plate 20 is secured to the contact 17. The piate 20 is extended downward
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 at the place 191 after the main contact has been ruptured. The movable
shunt contact proper is a block of carbon 21 supported in a socket 22 at tho
ends of arms 23 pivoted to the arm or arms 18 at 232 and connected by a spring
or springs 24 to the brackets 11. The lever 26 for opening and closing the
breaker is attached to a sleeve 201 enclosing the pin 101 and a toggle link 27
connects the pivot 232 to the end of the lever 20. Said link is of such a length
that when the breaker is closed as shewn in Figure 1, the pivots 232, 271 and 101
do not lie in a straight line but the pivot 271 is slightly above the line joining
the other two pivots. The shapes of the various levers can be clearly seen from
Figures 1 and 2 and need not be further described.
In order to make the toggle mechanism work very easily the various pivots
are made with knife edges, the pivot 232 being shewn in Figure 3, 271 in
Figure 4 and 101 in Figure 5. The general construction of these pivots is the
same, each one has a portion cut away so as to leave a sector forming a knife
edge (233 in Figure 3) which rests in a sectorial opening in a bush, this opening
being of greater angular aperture than the knife edge, such a bush is indicated
at 234 in Figure 3. This pivot is fixed as follows:-
The cylindrical end portions are loosely fitted in orifices in the levers 23
and 18, while the bush 234 is held in the end of the link 27 in the manner
indicated in dotted lines in Figure 1. Owing to the fact that the angular aperture
of the sector cut out of the bush 234 is greater than the angle of the sector 233
of the pin, it is obvious that relative movement of the knife edge and bush can
occur. A similar plan is followed with regard to the other two toggle pivots,
the pivot pin 271 having plain cylindrical portions at its ends being held in
orifices in the ends of the arms 262 of the lever 26, and the knife edge sector
portion 272 resting in a sector in a bush 273 which is located in the end of the
link 27. In the case of the pivot 101 the knife edges or sector portions 103
are located in bushes 104 provided in the brackets 11.
The action of the breaker is as follows:-
If the current through terminal 3 exceeds a predetermined amount, the
horseshoe 8 being magnetized beyond a certain extent, the armature 9 is attracted,
thereby moving the lever 10 on its pivot and causing the other end of said lever
to strike against a projection 28 on the arm 26 and moving said arm on its
knife edges in the brackets 11 until the pivot 271 passes over its dead centre
which is the line joining pivots 232 and 101. The springs 24 acting in con-
junction with gravity will throw the movable members of the circuit breaker
cutward and downward, and it will be seen that the main portion 17 will first
break contact with the face of the terminal 2, then the spring 20 will break
contact at the part 19ª, and finally the circuit will be broken between the
infusible blocks 7 and 21. The knife edges in the pivots cause the circuit
breaker to open very quickly and easily when once the predetermined strength
of current has been exceeded. In order to close the breaker the handle of the
arm 26 will be pressed downwards until the pivot 271 passes above the line
joining pivots 232 and 101.
The circuit breaker shewn in Figures 7 and 8 is similar to that shewn in the
earlier figures, but designed with a view to use on railway vehicles and the
operative parts are enclosed in a casing. The stationary terminal 29 to which the
main conductor 30 is connected has also connected to it one terminal of the actuat-
ing coil 31 of the breaker, the other terminal of said coil being electrically
connected to the movable member 17 of the breaker. Said movable member

page_text: is pivoted at 34 and a spring such as the spiral spring 33 is provided for throwing
said movable member outward when released. The second main conductor 35
is connected to a terminal block 36 the contact face of which is formed by a
bundle of laminae 37 adapted to be engaged by the movable member 17 or by a
block 321 set in its face. The end of the blade. 17 is received between two spring
plates 38 also secured to the terminal 36, these serving as the shunt contacts of
the breakers. The operating lever 26 is mounted upon the pivot 101 and is
joined to the movable member 17 of the circuit breaker by toggle links 27.
The pivots of these parts (shewn at 101, 271 and 232) are knife edge pivots
similar to those above described. The releasing mechanism comprises an
armature 47 pivoted in a bracket 48 and its other end pivoted to an arm or
rod 52 which carries a pin 53, this pin engaging with the toggle lever mechanism
so that when the armature 47 is attracted by the core 46 of the coil 31, the
rod or arm 52 is moved and the pin 53 pushes the toggle lever over its dead
centre, thereby enabling the spring 33 to throw the movable member 17 outwards
and thus break the circuit. The armature 47 is provided with an adjusting
means such as the spring 50 and nuts 51 so that the strength of current required
in the arm 31 to operate the circuit breaker can be adjusted. The circuit
breaker is shewn closed in full lines in Figure 7, the open position being shewn
in dotted lines.
The knife edge bearings may be varied in number as well as in structure and
arrangement from what has been shewn and described, although the construction
shewn in the drawings is a very suitable one for the purpose.
Doted the 21st day of October 1899.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant,
1, GILBERT WRIGHT, of 409, Ross Avenue, Wilkinsburg, in the County of
Allegheny, State of Pennsylvania, United States of America, Electrical Engineer,
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:-
My invention relates to circuit breakers by means of which the circuit is
automatically opened when the current therein exceeds a pre-determined
amount.
The invention consists in a circuit breaker with a toggle lever mechanism for
locking the breaker in the position in which the circuit is closed and having an
electro-magnetic device for operating the mechanism to open the circuit. In
order that the mechanism shall be easily operated to open and close the circuit
the toggle levers are provided with knife edge bearings so as to reduce the
friction.
In the drawings filed with my Provisional Specification.
Figure 1 is a side elevation, and
Figure 2 a front elevation of one form of my improved circuit breaker shewn
in the closed position.
and
Figures 3, 4 and 5 are perspective views of the pivots shewing the knife edges,
Figure 6 is a front view shewing the electromagnetic releasing device.

page_text: Figure 7 is an under plan view of another form, and
Figure 8 is a transverse section of the device shewn in Figure 7.
1 is a non-conducting base upon which are mounted the stationary terminals 2
and 3 to which the circuit conductors are connected. The terminal 2 has an
upward extension 5 carrying a socket 6 in which is mounted a block 7 of carbon.
The lower terminal 3. is partially surrounded by a piece of iron 8 which may
be laminated when the current breaker is to be used for alternating currents
and roughly forms a horseshoe (see Figure 6). The armature 9 of the electro-
magnet 8 is supported on arms 10 pivoted at 101 to the brackets 11 secured to
the base and said arms are joined by a transverse bar 12 so as to form a fork
as will be readily seen from Figure 3 and carry an adjustable weight 14.
The main movable portion of the circuit breaker comprises a bundle of curved
laminae 17 which are riveted to an arm. 18 pivoted at 181 in the brackets 11.
For the purpose of affording a final contact with the terminal 2 after the main
portion of the part 17 has left such terminal, the block 19 mounted on the
spring plate 20 is secured to the contact 17. The plate 20 is extended downward
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 at the place 191 after the main contact has been ruptured.. The movable
shunt contact proper is a block of carbon 21 supported in a socket 22 at the
ends of arms 23 pivoted to the arm or arms 18 at 232 and connected by a spring
or springs 24 to the brackets 11. The lever 26 for opening and closing the
breaker is attached to a sleeve 261 enclosing the pin 101 and a toggle link 27
connects the pivot 232 to the end of the lever 26. Said link is of such a length
that when the breaker is closed as shewn in Figure 1, the pivots 232, 271 and 101
do not lie in a straight line but the pivot 271 is slightly above the line joining
the other two pivots. The shapes of the various levers can be clearly seen from
Figures and 2 and need not be further described.
In order to make the toggle mechanism work very easily the various pivots
are made with knife edges, the pivot 232 being shewn in Figure 3, 271 in
Figure 4 and 101 in Figure 5. The general construction of these pivots is the
same, each one has a portion cut away so to leave a sector forming a knife
edge (233 in Figure 3) which rests in a sectorial opening in a bush. this opening
being of greater angular aperture than the knife edge, such a bush is indicated
at 234 in Figure 3. This pivot is fixed as follows:-
The cylindrical end portions are loosely fitted in orifices in the levers 23
and 18, while the bush 234 is held in the end of the link 27 in the manner
indicated in dotted lines in Figure 1. Owing to the fact that the angular aperture
of the sector cut out of the bush 234 is greater than the angle of the sector 233
of the pin, it is obvious that relative movement of the knife edge and bush can
occur. A similar plan is followed with regard to the other two toggle pivots,
the pivot pin 271 having plain cylindrical portions at its ends being held in
orifices in the ends of the arms 262 of the lever 26, and the knife edge sector
portion 272 resting in a sector in a bush 273 which is located in the end of the
link 27. In the case of the pivot 101 the knife edges or sector portions 103
are located in bushes 104 provided in the brackets 11.
The action of the breaker is as follows:-
If the current through terminal 3 exceeds a predetermined amount, the
horseshoe 8 being magnetised beyond a certain extent, the armature 9 is attracted,
thereby moving the lever 10 on its pivot and causing the other end of said lever
to strike against a projection 28 on the arm 26 and moving said arm on its
knife edges in the brackets 11 until the pivot 271 passes over its dead centre
which is the line joining pivots 232 and 101. The springs 24 acting in con-
junction with gravity will throw the movable members of the circuit breaker
outward and downward, and it will be seen that the main portion 17 will first
break contact with the face of the terminal 2. then the spring 20 will break
contact at the part 191, and finally the circuit will be broken between the

page_text: infusible blocks 7 and 21. The knife edges in the pivots cause the circuit
breaker to open very quickly and easily when once the predetermined strength
of current has been exceeded. In order to close the breaker the handle on the
arm 26 will be pressed downwards until the pivot 271 passes above the line
joining pivots 232 and 101.
The circuit breaker shewn in Figures 7 and 8 is similar to that shewn in the
earlier figures, but designed with a view to use on railway vehicles and the
operative parts are enclosed in a casing. The stationary terminal 29 to which the
main conductor 30 is connected has also connected to it one terminal of the actua-
ing coil 31 of the breaker, the other terminal of said coil being electrically
connected to the movable member 17 of the breaker. Said movable member
is pivoted at 34 and a spring such as the spiral spring 33 is provided for throwing
said movable member outward when released. The second main conductor 35
is connected to a terminal block 36 the contact face of which is formed by a
bundle of laminae 37 adapted to be engaged by the movable member 17 or by a
block 381 set in its face. The end of the blade 17 is received between two spring
plates 38 also secured to the terminal 36, these serving as the shunt contacts of
the breakers.
The operating lever 26 is mounted upon the pivot 101 and is
joined to the movable member 17 of the circuit breaker by toggle links 27.
The pivots of these parts (shewn- at 101, 271 and 232) are knife edge pivots
similar to those above described. The releasing mechanism comprises an
armature 47 pivoted in a bracket 48 and its other end pivoted to an arm or
rod 52 which carries a pin 53, this pin engaging with the toggle lever mechanism
so that when the armature 47 is attracted by the core 46 of the coil 31, the
rod or arm 52 is moved and the pin 53 pushes the toggle lever over its dead
centre, thereby enabling the spring 33 to throw the movable member 17 outwards
and thus break the circuit. The armature 47 is provided with an adjusting
means such as the spring 50 and nuts 51 so that the strength of current required
in the arm 31 to operate the circuit breaker can be adjusted. The circuit
breaker is shewn closed in full lines in Figure 7, the open position being shewn
in dotted lines.
The knife edge bearings may be varied in number as well as in structure and
arrangement from what has been shewn and described, although the construction
shewn in the drawings is a very suitable one for the purpose.
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―
1. An electric circuit breaker having a movable member composed of a number
of metal laminae, the operating lever being connected with said movable member
through a toggle mechanism which is arranged to lock the switch in the closed
position and with knife edge bearings for the toggle levers to enable the mechanism
to work very quickly and easily, substantially as described.
2. For circuit breakers knife edge bearings constructed substantially as
described with reference to Figures 3 to 5 of the accompanying drawings.
3. Electric circuit breakers constructed according to either of the forms shewn
in the accompanying drawings and operating as described.
1
1000
Darcu
F. W. LE TALL,
Chartered Patent Agent,
The Westinghouse Patent Bureau, Westinghouse Building,
Norfolk Street, Strand, London, W.C.