US4387280A — High speed hydraulically-actuated operating syste…

Claim 1

Independent Claim 420 words

An hydraulically-actuated operating system for an electric circuit breaker comprising: a fluid motor comprising a cylinder, a piston rod and a movable piston mounted on said piston rod and adapted to move in an opening direction within said cylinder to open an electric circuit breaker and in a reverse direction within said cylinder during closing of the circuit breaker; an accumulator for supplying pressurized liquid to a piston-actuating space within said cylinder; a normally-closed valve located hydraulically between said accumulator and said actuating space and openable to establish communication between said accumulator and said actuating space so that pressurized liquid from said accumulator can flow through said valve to said actuating space to drive said piston in an opening direction, said valve comprising a movable valve member that is movable from a valve-closed to a valve-open position to open said valve and is returnable to said valve-closed position to close said valve; a vent located hydraulically downstream of said valve with respect to said accumulator for affording communication between said actuating space and a low pressure region; flow control means for restricting leakage through said vent to a rate that prevents said leakage from substantially detracting from the development of pressure within said actuating space during the period from initial opening of said valve to the time when said piston has moved through a substantial portion of its opening stroke, said flow control means acting following such period and while said valve is still open to allow effective leakage through said vent; said accumulator having a limited capacity that results in the pressure within said actuating space decaying promptly to a low value as a result of effective leakage through a circuit-breaker opening stroke and while said movable valve member is in its valve-open position; means for restoring said movable valve member to its closed position in response to said pressure decay in said actuating space; and dashpotting means comprising a shaft separate from said piston rod and disposed in axial alignment with said piston and opposite said actuating space, an abutment disposed at one end of said shaft and adapted to engage an end of said piston, and means for retarding motion of said shaft connected to the other end of said shaft, said abutment being axially spaced from said piston such that said piston contacts said dashpotting means abutment after travelling through said substantial portion of its opening stroke; said dashpotting means comprising the sole motion-retarding means for substantially retarding motion of said piston in said opening direction.

Claim 2

Dependent Claim 420 words

An hydraulically-actuated operating system for an electric circuit breaker comprising: a fluid motor comprising a cylinder, a piston rod and a movable piston mounted on said piston rod and adapted to move in an opening direction within said cylinder to open an electric circuit breaker and in a reverse direction within said cylinder during closing of the circuit breaker; an accumulator for supplying pressurized liquid to a piston-actuating space within said cylinder; a normally-closed valve located hydraulically between said accumulator and said actuating space and openable to establish communication between said accumulator and said actuating space so that pressurized liquid from said accumulator can flow through said valve to said actuating space to drive said piston in an opening direction, said valve comprising a movable valve member that is movable from a valve-closed to a valve-open position to open said valve and is returnable to said valve-closed position to close said valve; a vent located hydraulically downstream of said valve with respect to said accumulator for affording communication between said actuating space and a low pressure region; flow control means for restricting leakage through said vent to a rate that prevents said leakage from substantially detracting from the development of pressure within said actuating space during the period from initial opening of said valve to the time when said piston has moved through a substantial portion of its opening stroke, said flow control means acting following such period and while said valve is still open to allow effective leakage through said vent; said accumulator having a limited capacity that results in the pressure within said actuating space decaying promptly to a low value as a result of effective leakage through a circuit-breaker opening stroke and while said movable valve member is in its valve-open position; means for restoring said movable valve member to its closed position in response to said pressure decay in said actuating space; and dashpotting means comprising a shaft separate from said piston rod and disposed in axial alignment with said piston and opposite said actuating space, an abutment disposed at one end of said shaft and adapted to engage an end of said piston, and means for retarding motion of said shaft connected to the other end of said shaft, said abutment being axially spaced from said piston such that said piston contacts said dashpotting means abutment after travelling through said substantial portion of its opening stroke; said dashpotting means comprising the sole motion-retarding means for substantially retarding motion of said piston in said opening direction.

Claim 3

Dependent Claim 49 words

The operating system of claim 1 in which said flow control means comprises a long restricted tube hydraulically in series with said vent between said actuating space and said low pressure region for containing a column of liquid which must be accelerated to allow effective leakage through said vent.

Claim 4

Dependent Claim 159 words

The operating system of claim 2 wherein said dashpotting means comprises: an enclosure having a generally cylindrical sleeve disposed therein; said sleeve having generally radially extending passages therethrough; a plunger disposed within said enclosure generally concentrically within said sleeve; a shaft connected to said plunger at one end thereof and connected to an abutment at the other end thereof; said shaft extending through an opening in the top wall of said enclosure and said abutment being disposed in spaced, axially aligned relationship with said piston of said fluid motor when the circuit breaker is closed and; said enclosure contains a volume of hydraulic liquid; and said passages in said sleeve are sized such that hydraulic resistance to vertically downward movement increases as said plunger moves downward within said sleeve, thereby causing near the end of the downward movement of said piston a pressure rise in said actuating space such that leakage flow of liquid through said vent is accelerated.

Claim 5

Dependent Claim 122 words

The operating system of claim 1 in which said piston occupies a circuit-breaker closed position when the circuit breaker is closed and a circuit-breaker open position when the circuit breaker is open, and said operating system further comprises: releasable latching means for holding said piston in said circuit-breaker open position after a circuit-breaker opening operation; closing means operable upon release of said latching means for returning said piston to its circuit-breaker closed position; and wherein: said vent is sufficiently unrestricted when said valve is closed to allow pressurized liquid ahead of said piston during its return motion to circuit-breaker closed position to be exhausted from said actuating space without developing sufficient pressure to actuate said valve member out of its valve-closed position.

Claim 6

Dependent Claim 97 words

The operating system of claim 2 in combination with: pumping means operable to supply pressurized liquid to said accumulator for recharging said accumulator; means for causing said pumping means to operate when the pressure in said accumulator is below a predetermined level, thereby supplying pressurized liquid to said accumulator; and a restriction disposed hydraulically between said pumping means and said accumulator that limits the rate at which the pumping means supplies liquid to said accumulator sufficiently so that accumulator-recharging is prevented while said valve member is in valve-open position and effective leakage is occurring through said vent.

Claim 7

Dependent Claim 161 words

The operating system of claim 5 wherein said dashpotting means comprises: an enclosure having a generally cylindrical sleeve disposed therein; said sleeve having generally radially extending passages therethrough; a plunger disposed within said enclosure generally concentrically within said sleeve; a shaft connected to said plunger at one end thereof and connected to an abutment at the other end thereof; said shaft extending through an opening in the top wall of said enclosure and said abutment being disposed in spaced, axially aligned relationship with said piston of said fluid motor when said contacts are in the closed position; and said enclosure contains a volume of hydraulic liquid; and said passages in said sleeve are sized such that hydraulic resistance to vertically downward movement increases as said plunger moves downward within said sleeve, thereby causing near the end of the downward movement of said piston a pressure rise in said actuating space such that leakage flow of liquid through said vent is accelerated.

Claim 8

Dependent Claim 72 words

The operating system of claim 1 in which: said valve consitutes a main valve and said movable valve member consitutes a movable main valve member; said vent affords free communication between said actuating space and said low pressure region when said main valve is closed; and restoration of said movable main valve member to its closed position restores free communication through said vent between said actuating space and said low pressure region.

Claim 9

Dependent Claim 156 words

The operating system of claim 7 wherein said dashpotting means comprises: an enclosure having a generally cylindrical sleeve disposed therein; said sleeve having generally radially extending passages therethrough; a plunger disposed within said enclosure generally concentrically within said sleeve; a shaft connected to said plunger at one end thereof and connected to an abutment at the other end thereof; said shaft extending through an opening in the top wall of said enclosure and said abutment being disposed in spaced, axially aligned relationship with said piston of said fluid motor when the circuit breaker is closed; and said enclosure contains a volume of hydraulic liquid; and said passages in said sleeve are sized such that hydraulic resistance to vertically downward movement increases as said plunger moves downward within said sleeve, thereby causing near the end of said opening stroke a pressure rise in said actuating space such that leakage flow of liquid through said vent is accelerated.

Claim 10

Independent Claim 191 words

A method of operating a hydraulically actuated operating system for an electric circuit breaker comprising the steps of: pressurizing a supply of a liquid breaker-operating medium disposed within a pressure accumulator; supplying an unimpeded flow of said pressurized medium from said accumulator to a breaker-opening space of a fluid motor operably connected to one of the contacts of said circuit breaker through an unimpeded flow path hydraulically connecting said accumulator and said breaker-operating space by opening a valve disposed hydraulically between said accumulator and said breaker-opening space to move a piston rod of said fluid motor and a piston of said fluid motor and mounted on said piston rod in a breaker-opening direction; and following travel of said piston through a substantial portion of its opening stroke, contacting said piston to an abutment of a dashpotting means comprising a shaft separate from said piston rod and disposed in axial alignment with said piston and means for retarding motion of said shaft connected to said shaft, said abutment being thertofore separated from said piston; said dashpotting means comprising sole motion-retarding means for substantially retarding motion of said piston in said breaker-opening direction.

Claim 11

Independent Claim 191 words

A method of operating a hydraulically actuated operating system for an electric circuit breaker comprising the steps of: pressurizing a supply of a liquid breaker-operating medium disposed within a pressure accumulator; supplying an unimpeded flow of said pressurized medium from said accumulator to a breaker-opening space of a fluid motor operably connected to one of the contacts of said circuit breaker through an unimpeded flow path hydraulically connecting said accumulator and said breaker-operating space by opening a valve disposed hydraulically between said accumulator and said breaker-opening space to move a piston rod of said fluid motor and a piston of said fluid motor and mounted on said piston rod in a breaker-opening direction; and following travel of said piston through a substantial portion of its opening stroke, contacting said piston to an abutment of a dashpotting means comprising a shaft separate from said piston rod and disposed in axial alignment with said piston and means for retarding motion of said shaft connected to said shaft, said abutment being thertofore separated from said piston; said dashpotting means comprising sole motion-retarding means for substantially retarding motion of said piston in said breaker-opening direction.

Claim 12

Dependent Claim 23 words

The method of claim 9 further comprising latching said breaker in said breaker-open position until a predetermined time after said breaker opening step.

Claim 13

Dependent Claim 45 words

The method of claim 10 further comprising biasing said breaker in said breaker-closed position and biasing said valve in a valve-closed position such that following said latching-open step; releasing said breaker from said latched-open position and allowing said breaker to return to said breaker-closed position.

Claim 14

Dependent Claim 38 words

The method of claim 11 further comprising the step of after said valve is returned to said breaker-closed position recharging said accumulator by admitting a flow of pressurized liquid into said accumulator through the body of said valve.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-06-06	1986-12-06	1987-06-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-06-06	1990-12-06	1991-06-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-06-06	1994-12-06	1995-06-07	$7700.00	Window Closed / Lapsed

High speed hydraulically-actuated operating system for an electric circuit breaker

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