US2464237A

US2464237A - Fluid pressure actuated switch

Info

Publication number: US2464237A
Application number: US488146A
Authority: US
Inventors: Arthur C Kelle
Original assignee: Allis Chalmers Corp
Current assignee: Allis Chalmers Corp
Priority date: 1943-05-24
Filing date: 1943-05-24
Publication date: 1949-03-15
Anticipated expiration: 1966-03-15

Description

March 15, 1949. A. c. KELLE 2,464,237

FLUID PRESSURE ACTUA'IED SWITCH Filed lay 24, 1943 Patented Mar. "15, 1949 FLUID PRESSURE ACTUATED SWITCH Arthur C. Kelle, Stoughton, Mass., assignor to Allis-Chalmers Manufacturing Company, Milwaukee, Wis., a corporation of Delaware Application May 24, 1943, Serial No. 488,146

This invention relates in general to a pneumatic control system and particularly to an improved control system and parts thereof suitable for operating a gas blast circuit breaker. As the currents to be interrupted by circuit breakers of the gas blast type become increasingly greater and as it becomes desirable both to operate such circuit breakers in shorter times and to encase the circuit breakers in small metal housings, the slower operating systems and the conventional arrangement of elements in the prior art circuit breakers cannot meet the desired time and space requirements.

It is therefore an object of the present invention to provide a pneumatic operating system to provide a gas blast circuit breaker having separately operated main current carrying contacts and isolating contacts with interlocks insuring a proper sequence of operation.

It is also an object of the present invention to provide a gas blast circuit breaker with fluid motor contact operators that are rapidly reversible by reason of relief of back pressure at a predetermined point of the piston stroke.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawing in which the single figure is a diagrammatic representation of a gas blast circuit breaker operating system embodying the present invention.

In the drawing, an electric circuit (not shown) connected to conductors and 3| isshown as controlled by a circuit breaker of the gas blast type. The conductors 30 and 3| extend through studs 9 to contact blocks which have'thereon fixed contacts 3 shown as bridged by a conducting movable main or bridging contact 4. The contacts 3, 4 are contacts of high current carrying capacity and are positioned where heat can easily be dissipated therefrom and are arranged in a magnetic loop such that current flow tends.

18 Claims. (Cl. 200-82) connected in series. A reservoir containing gas suitable for are extinguishing is shown at l0 and for purposes of illustration the gas therein will be considered to be air maintained under pressure of the order of 100 to 500 pounds per square inch. In general, the flow of air is from the tank 10, through a blast valve II and a manifold 45 to the arcing contact chamber 28. Air travel continues from the arcing contact chamber 26 through the fixed arcing contact 1 into a gas cooling device or mufiler l2 and through an exhaust pipe l3 to atmosphere.

Separate fluid motors 42, 5|, 52 and 53 are utilized to operate the arcing contacts, disconnect contacts, the bridging contacts and the blast valve, respectively. Motor 5! is provided with a piston 20 having rod 2| movable therewith and connected through linkage including a cam member 22 to the movable disconnect contact 5. Motor 52 has a piston l6 having a rod l1 connected through linkage to the movable bridging member 4. The cam member l8, operably connected to the rod ll, cooperates with cam 22 to prevent opening of the disconnect contact 5 unless the bridging contact 4 is in open position. Also, a camming action of cam l8 closes the disconnect contact 5, if open, upon movement of the bridging contact 4 to closed position.

- In the circuit breaker as shown in the drawing, the contacts are all shown in the closed position and current flow is from conductor 30 through contacts 3, 4 to conductor 3|. solenoid valve l4 initiates the opening operation of the circuit breaker. Air under pressure from tank I0 is supplied through pipe 15, through the solenoid valve I4, through the pipe 16 to slide valve12. With the slide valve 12 in the position shown, air passes through the slide valve, through pipe 84 to the chamber 68 of the fluid motor 52.

As pressure rises in chamber 68, valve 10 is operated admitting air to the underside of piston 16. Movement of piston I6 upward causes piston rod I! to move the linkage to break toggle to the left as viewed in'the drawing, thereby opening bridging contact 4. This movement of rod l1 upward rotates the cam l8 in a counterclockwise direction and clears the path of movement of the cam 22.

Upon movement of the piston l6 upward a predetermined distance, slide valve 12, connected to move with rod 11, closes off pipe 84 from supply pipe 18 and opens pipe I8 to pipe 46. With pipe 48 supplied with air under pressure, the blast valve motor 53 is operated; Air is supplied under piston 44 and, as outlet port 48 is covered by Operat on of v 3 slide valve 49, the piston 44 is 'moved upward opening blast valve ll. Movement of piston 44 at the top of the stroke is arrested and the shock absorbed by resilient material 90.

Opening of the blast valve ll admits air to manifold 45 and thereby to the arcing contact chamber26 and to the cylinder containing arcing contact operating piston 42. Movement of the piston 42 upward opens the arcing contact 8, allowing the air to blast through orifice contact I. An auxiliary electrode 86 may be provided and connected to a resistance (not shown) which may be wound on the cooling chamber l2, which re-,

sistance is connected to contact block 40 by conductor 43. The arc gases are cooled in the muffler l2 and exhausted through pipe l3 to atmosphere.

When air is supplied to the manifold 45 by opening of the main blast valve I I, pressure air is supplied through pipe 18 to the chamber 58 of fluid motor 5|. In order to assure a proper sequence of operation of arcing contact 8 and disconnecting contact 5, a needle valve 19 in the line 18 isprovided for adjustment of the air flow therein. .As pressure builds up in chamber 58, the valve 60 is opened admitting air under pressure to thebottom of piston 20. Movement of piston 20 and piston rod 2| upward rotates the cam member 22 in a clockwise direction about itspivot 81 opening the movable disconnect contact 5.

At a predetermined opening of the disconnect contact 5, links 50 move a slide valve 49 to uncover an exhaust port 48 and open an inlet port 41. This releases pressure beneath piston 44 and allows tank pressure to be applied on the top of the piston, thus rapidly reclosing valve l l. Upon closing of valve ll, pressure air is shut off from chamber 26, permitting arcing contact 8 to reclose under bias of a spring (not shown). Rapid reclosing of blast valve M and arcing contact 8 is very necessary from the standpoints of time of circuit breaker reclosing and of air conservation.

Fluid motors 5|, 52 and 53 are designed to permit a fast reclosing of the circuit breaker. Motor 5| is provided with a dumping valve 28 providing for release of pressure underneath piston 20 at or near the end of the upward stroke. An operating member 55 on rod 2i operates poppet valve 54 permitting pressure in the chamber 58 to leak off to atmosphere. The difference of pressures under the piston 25 and in chamber 58 forces the valve 28 downward against the pressure of its biasing spring, thereby opening the space underneath the piston 20 to atmosphere and immediately relieving the pressure therein.

In the motor 52 a similar action takes place, poppet valve 64 is operated by operating member 65 movable with the piston rod ll. Operation of valve 64 lowers the pressure in chamber 68 thereby operating dumping valve 88 to permit a rapid release of pressure under piston l6. Motors 5| and 52 are therefore ready for immediate reversal.

Due to the improved fluid motors and to the rapid interruption of the circuit, the foregoing operation is completed in a few cycles. The circuit breaker is ready for reclosing which may be effected by energization of the solenoid valve l5. With solenoid valve l4 closed, pressure air from the pipe is supplied through solenoid valve l5 and pipe i1 to

chambers

59 and 69 of motors 5| and 52. With downward movement of pistons and IS the bridging contacts 4, 3 and the disconnect contacts 5, 5 are reclosed, with the limitation provided by cams l8 and 22 that the bridging contacts 3, 4 must be reclosed subsequent to closure of disconnect contacts 5, 8. If movement of contacts 3, 4 tends to be faster than movement of contacts 5, 6, movement of cam [8 in a clockwise direction forces cam 22 to close contact 5. This prevents arcing at the bridging contacts 3, 4 and provides for closing of the circuit at the disconnect contacts 5, 6 especially designed for closing against heavy currents.

Upon movement of pistons 20 and I6 downward, operating

members

51 and 61 operate poppet valves 56 and 66 to provide release of pressure above the pistons 20 and I6 in a manner similar to the pressure release afforded by valves 54 and 64. Movement of piston rod i'l downward moves slide valve I2 to the'position shown in the drawing and the blast valve having been closed, the circuit breaker is immediately ready for a subsequent opening operation. Considerable saving in reclosing time is effected by the simultaneous energization of motors 5| and 52 for closing and by insuring of the proper closing sequence by the abutting cam members l8 and 22. The interlock afforded by cams l8 and 22 involves no loss of time.

In order to arrange the elements of a gas blast circuit breaker as shown, so that it may be encased in a metal housing as small or smaller than the housing now utilized for an oil circuit breaker of equivalent current rating, many problems were solved. It is generally desirable in a vertical lift switchgear to have the studs 9 enter the housing through the top of the breaker so that they may connect to overhead circuit connections.

The circuit breaker is enclosed in a housing 35 and is movable horizontally on wheels into a cell. The entire circuit breaker and housing is moved vertically from the floor 37 to a position in which conductors 30 and 3! are connected to the circuit to be controlled. The circuit breaker housing 36 shown at the left is the back of the circuit breaker and hence the first to enter into the cell. To illustrate the need for electrical clearances and electrical safety, the circuit breaker may be considered to be divided into two portions. All parts that maybe at high potential are in the rear portion and these include the studs 9 and all of the contacts. The front portion contains only elements that are either at ground potential or that present an outer surface of insulating material thus making the front of the circuit breaker electrically dead and therefore safer for the operator. The disconnecting contacts 5, ii are so arranged that if upon a faulty operation an arc is drawn, such arc will be blown onto the adjacent grounded housing 36.

The circuit breaker cannot be moved into the cell far enough to be raised to circuit connected position shown unless the disconnect contact 5 is in open poistion. This is assured by provision of stop 24 on the .cell framework which stop cooperates with a link 23 connected to the cam linkage 22, whereby movement of the circuit breaker to the left forces cam 22 to rotate in a clockwise direction opening the contact 5 providing bridging contact 4 is also open. If the contact 4 is not open, cam l8 prevents movement of cam 22, and the breaker cannot move into the cell into proper position for raising into the position shown. When the breaker is in the open position, the circuit breaker is then lifted to circuit connected position by a lifting means (not shown). When the circuit breaker is lifted to circuit connected position, member 23 may move into a slot 25, thereby permitting closing operation of the circuit breaker. A slot 35 in a locking member 34, operated by the circuit breaker lifting and lowering mechanism, prevents lowering of the circuit breaker unless in open position. A slot "permits link I! to be in the slot 35 or on the top or member 34 if the slot 35 is not in alinement with link 89. The link 89 is lifted clear 01- member 34 if the disconnect is in open position. Although the various elements of the circuit breaker system have been described as operating in conjunction with each other, the improvements disclosed have utility other than with all of the elements shown and described. For example, the fluid motors ii and 52 may be utilized for any purpose where quick reversal of a fluid motor is desirable. While the disclosed arrangement of bridging contacts 3, 4 is desirable for circuit breakers'of high current rating, these contacts may be omitted in the lower current ratings.

The improvements utilized in efiecting a quick reclosure of the blast valve 1 l, although shown as initiated by movement of the disconnect contact 5, may as well be effected by an isolating movement of the arcing contacts 1, 8 in cases where ing contacts, means comprising a main valve for For simplicity and clarity of disclosure, a single pole circuit breaker has been described and shown, although usually a multiple circuit breaker is operated. In such cases, the manifold extends to the interrupting chambers of the addifrom the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. In combination, a pair of cooperatively relatively movable arcing contacts, a pair of cooperating relatively movable disconnect contacts serially connected with said arcing contacts, cooperating fixed and movable bridging contacts for shunting said series connected arcing and disconnect contacts, means for closing said arcing contacts, means operable by fluid under pressure for closing said disconnect contacts, means operable by fluid under pressure for closing said bridging contacts, valve means for simultaneously energizing said fluid pressure closing means, and means comprising abutment members associated with said operating means for insuring closure of said disconnect contactsprior to closing of said bridging contacts.

2. In combination, a pair of cooperating relatively movable arcing contacts, a pair of cooperating relatively movable disconnect contacts serially connected with said arcing contacts, cooperating flxed and movable bridging contacts for shunting said series connected arcing and disconnect contacts, means for operating said areing contacts, means operable by fluid under pressure for operating said disconnect contacts, means operable by fluid under pressure for operating said bridging contacts, valve means for simultaneously energizing said fluid pressure operating means to close said disconnect and bridging contacts, and means comprising abutment memestablishing a flow of gas across said arcing contacts when in open position, a pair of additional contacts in circuit with said arcing contacts, fluid pressure means for operating said arcing contacts to open position, fluid pressure means for operating said additional contacts to open position, a fluid pressure operated motor for closing said main valve, an auxiliary valve for venting one side of said motor during the valve-closing stroke thereof, and means operative in response to a predetermined contact opening operation of said additional contact operating means for initiating the operation of said motor and for controlling said auxiliary valve.

1. In combination, a pair of cooperating arcing contacts, means comprising a main valve for establishing a flow of gas across said arcing contacts when in current interrupting position, means for isolating said arcing contacts, a fluid pressure operated motor for operating said main valve, and an auxiliary valve operative in response to operation of said arcing contact isolating means for applying fluid under pressure to said motor for rapidly reclosing said main valve.

, 5. In an electric circuit breaker, a fluid pressure operated motor, a source of fluid under pressure, a reversible fluid motor comprising a piston and cylinder arranged to be connected to said source, means operatively relating said fluid motor to said circuit breaker for operating the same, a dumping valve of the type responsive to a change of a difference in pressure interposed between said source and said fluid motor, and means for operating said dumping valve upon predetermined movement of said piston in said cylinder, said means including auxiliary valve means for controlling the difference in pressure to which said dumping valve is responsive.

6. In a fluid pressure motor, a relatively movable cylinder and piston, a source of fluid under pressure, means for selectively connectin said source of fluid to said cylinder above or below said piston, means interposed between said source and said piston for rapidly relieving fluid pressure tending to retard reversal of said fluid motor prior to such reversal, said fluid pressure relieving means including a movable valve element responsive to a change of difference in pressure and an auxiliary valve for controlling said difference in pressure, and means for operating said auxiliary valve comprising a member operatively connected to said piston.

'7. A metalclad gas blast circuit breaker comprising a housing provided with one portion containing' studs for connection of said circuit breaker to the controlled circuit, said portion also containing cooperating arcing contacts, and said portion further containin cooperating disconnect contacts in series with said arcing contacts, means for establishing a flow of gas across said arcing contacts, means whereby said disconnect contacts open directly adjacent a wall of said housing, said housing being provided with another portion containing a reservoir for said gas under pressure and said another portion containing a cooler for gas exhausted from said arcing contacts, and means whereby all elements in said another portion are grounded or are externally insulated.

8. In combination, a cell, a circuit breaker removable from said cell, said circuit breaker comprising a pair of cooperating arcin contacts and a pair of disconnect contacts in series with said arcing contacts, and means obstructing completion of movement of said circuit breaker into said cell unless said disconnect contacts are in contact separated position.

9. In combination, a cell, a circuit breaker removable from said cell, said circuit breaker comprising a pair of cooperating arcing contacts, a pair of cooperating disconnect contacts in series with said arcing contacts and a pair of cooperating main current carrying contacts in parallel circuit with said series connected disconnect and arcing contacts, means obstructing completion of movement of said circuit breaker into said cell unless said main current carrying contacts are in contact separated position.

10. In combination, a pair of cooperating relatively movable arcin contacts, a pair of cooperating relatively movable disconnect contacts serially connected with said arcing contacts, cooperating fixed and movable bridging contacts for shunting said series connected arcing and disconnect contacts, means for operating said arcing contacts, means operable by fluid under pressure for operating said disconnect contacts, means operable by fluid under pressure for operating said bridging contacts, valvemeans for simultaneously energizing said fluid pressure operating means to close said disconnect and bridging contacts, means comprising abutment members associated with said fluid pressure operating means for insuring closure of said disconnect contacts prior to closing of said bridging contacts and for maintaining said disconnect contacts in closed position until after opening of said bridging contacts, and additional valve means operative in response to operation of said bridging contacts for sequentially energizing said fluid pressure operating means to open said disconnect and bridging contacts.

11. In combination, a cell, a circuit breaker, means for moving said circuit breaker in said cell from a circuit connected position to .a circuit disconnected position, said circuit breaker comprising cooperating arcing contacts, cooperating disconnect contacts in series with said arcing contacts and cooperating main current carrying contacts in parallel circuit with said series connected disconnect and arcing contacts, and means operable jointly in accordance with operation of said movin means and in accordance with operation of said disconnect contacts for controlling operation of said moving means.

12. In combination, a pair of cooperating relatively movable arcin contacts, a pair of cooperating relatively movable disconnect contacts serially connected with said arcing contacts, cooperating fixed and movable bridging contacts for shunting said series connected arcing and disconnect contacts, means for operating said arcing contacts, means operable by fluid under pressure for operating said disconnect contacts, means operable by fluid under pressure for operating said bridging contacts, valve means for simultaneously energizing said fluid pressure operating means to close said disconnect and bridging contacts, means comprising abutment members associated with said fluid pressure operating means for insuring closure of said disconnect contacts prior to closing of said bridging motor to'said circuit breaker for operating the same, means for selectively connecting said source of fluid to said cylinder above or below said piston, means interposed between said source and said piston for rapidly relieving fluid pressure tending to retard reversal of said fluid pressure motor prior to such reversal, said fluid pressure relieving means including a movable valve element responsive to a change of difierence in pressure and an auxiliary valve for controlling said difference in pressure, and means for operating said auxiliary valve comprising a member operatively connected to said piston.

14. In combination, a first pair of cooperating relatively movable contacts, a second pair of co operating relatively movable contacts, a source of fluid under pressure, a first fluid operated motor arranged to be supplied with'fiuid from said source and arranged to operate one of said first pair of contacts, a second fluid operated motor arranged to be supplied with fluid from said source and arranged to operate one of said second pair of contacts, a valve for simultaneously admitting fluid from said source to said fluid operated motors, a first abutment member operatively connected with said first fluid operated motor, and means comprising a second abutment member operatively connected with said second fluid motor for cooperatively engaging said first abutment member to transmit accelerating forces from said second fluid operated motor to said first fluid operated motor.

15. In combination, a first pair of cooperating relatively movable contacts, a second pair of cooperating relatively movable contacts, a source of fluid under pressure, a first fluid operated motor arranged to be supplied with fluid from said source and arranged to operate one of said first pair of contacts, a second fluid operated motor arranged to be supplied with fluid from said source and arranged to operate one of said second pair of contacts, a valve for simultaneously admitting fluid from said source to said fluid operated motors, a first abutment member operatively connected with said first fluid operated motor, and means comprising a second abutment member operatively connected with said second fluid motor for cooperatively engaging said first abutment member to transmit accelerating forces from said second fluid operated motor to said first fluid operated motor upon operation thereof in one direction and to insure operation of said first fluid operated motor prior to operation cf said second fluid operated motor upon operation thereof in another direction.

16. In a fluid pressure motor, a relatively movable cylinder and piston, a source of fluid under pressure, means for supplying said cylinder with fluid under pressure from said source for causing relative movement of said cylinder and piston, a first dumping valve responsive to the difference in pressure within said cylinder and an enclosed space outside thereof for rapidly relieving fluid pressure tending to retard reversal of said relative movement, and a second dumping valve operative in response to a predetermined relative movement between said cylinder and piston for venting said enclosed space to atmospliere and causing opening of said flrst dumping valve.

17. In combination, a pair of cooperating relatively movable arcing contacts. a pair of cooperating relatively movable disconnect contacts serially connected with said arcing contacts, 00- operating flxed and movable bridgin contacts for shunting said series connected arcing and disconnect contacts, means for closing said arcing contacts, means operable by fluid under pressure for operating said disconnect contacts, means operable by fluid under pressure for operating said bridging contacts, valve means for simultaneously energizing said fluid pressure operating means, and means comprising cooperatively engaging cam means associated with said operating means for said disconnect contacts and said operating means for said bridging contacts for I insuring sequential closure 01 said disconnect and bridging contacts and sequential opening of said go bridging and disconnect contacts.

18. In combination, a pair of cooperating relatively moving arcing contacts, a pair of relatively movable disconnect contacts serially connected with said arcing contacts, cooperatin fixed and movable bridging contacts for shunting said serially connected arcing and disconnect contacts, means for operating said arcing contacts, a source of fluid under pressure, a flrst reciprocable fluid motor for operating said disconnect contacts, a second reciprocable fluid motor for 10 operating said bridging contacts, a valve for simultaneously admitting fluid from said source to said first and second fluid motors, a first abutment member operatively connected with said first fluid motor, and means comprising a second abutment member operativeiy connected with said second fluid motor for cooperatively engagin said first abutment member to insure sequential closure of said disconnect and bridging con- 10 tacts upon operation of said fluid motors in one direction thereof and to transmit accelerating forces from the said second fluid motor to said flrst fluid motor upon operation thereof in another direction.

ARTHUR C. KELLE.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS.

Number Name Date 2,144,372 Haller et al'. Jan. 17, 1939 2,233,521 Ernst et al. Mar. 4, 1941 2,273,002 Mahoney Feb. 10, 1942 2, 82,153 Baker et al. May 5, 1942 2,287,039 Jansson June 23, 1942 2,303,492 Peterson et al. Dec. 1, 1942 2,351,903 Baker et al. June 20, 1944 2,360,687 Johnson Oct. 17, 1944 2,401,008 Ludwig et al May 28, 1946 Certificate of Correction Patent No. 2,464,237. March 15, 1949.

ARTHUR C. KELLE It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 5, line 46, claim 1, for cooperatively read cooperating;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 23rd day of August, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,464,237. March 15, 1949.

Column 5, line 46, claim 1, for cooperatively" read cooperating;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 23rd day of August, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.