US3890479A

US3890479A - Fast cut-out pneumatic switch

Info

Publication number: US3890479A
Application number: US316783A
Authority: US
Inventors: Edmond Thuries; Francois Joly
Original assignee: Cegelec SA
Current assignee: Cegelec SA; Delle Alsthom SA
Priority date: 1971-12-21
Filing date: 1972-12-20
Publication date: 1975-06-17
Anticipated expiration: 1992-06-17
Also published as: FR2165184A5

Abstract

Fast cut-out pneumatic switch using the action of a pressurized gas flowing through a valve surrounding the contact, to accelerate the opening of the latter, characterized in that the beginning of the opening operation of the contact and of the valve is effected by electrodynamic means controlled by an emission of current.

Description

[ June 17, 1975 4/1966 Francemm......,....,...... 200/148 BV ABSTRACT 2 Claims, 6 Drawing Figures 3.522.400 7/1970 Golota.......i..,,.............v

FOREIGN PATENTS OR APPLICATIONS Primary Examiner-Robert S. Macon Attorney, Agent, or FirmSughrue, Rothwell, Mion, Zinn & Macpeak Fast cut-out pneumatic switch using the action of a pressurized gas flowing through a valve surrounding the contact, to accelerate the opening of the latter, characterized in that the beginning of the opening operation of the contact and of the valve is effected by electrodynamic means controlled by an emission of current.

Inventors: Edmond Thuries, Pusignan;

Francois Joly, Lyon, both of France Assignee: Delle-Alsthom, Villeubanne, France Filed: Dec. 20, 1972 Appl. No.: 316,783

Foreign Application Priority Data Dec 21, 1971 200/148 BV; 200/148 R Int. C1.H01h 33/42 200/148 BU, 148 R References Cited UNITED STATES PATENTS 4/1969 Frowein.......,.,............. 200/148 BV United States Patent Thuries et al.

[ 1 FAST CUT-OUT PNEUMATIC SWITCH [58] Field 01' Search.................,.

PATENTEDJuu 17 ms SHEET 1 E 7 5 6 mm Mm R NK \N\ N m a PATENTEHJUN 1 7 I975 SHEET lxl $15 IZI:

FIG.6

SHEET WW? .p 0 f W/ 0000000 00 v x v x F PATENTEDJUN 17 ms FAST CUT-OUT PNEUMATIC SWITCH BACKGROUND OF THE INVENTION 1. Field of the Invention The invention concerns pneumatic switches intended to be opened within a very short time, for example in order to cancel defects in an electric circuit very rapidly.

2. Description of the Prior Art It is already known that it is possible to speed up the movement for the opening of a contact of a pneumatic switch by fitting round that contact a valve arranged inside a cut-out chamber forming a high-pressure compressed gas tank, and by making the contact zone communicate with a low-pressure enclosure, so that, when the contact and the valve open, an acceleration of the opening of the contact is caused by the action of the compressed gas flowing from the high-pressure tank towards the low-pressure tank.

SUMMARY OF THE INVENTION The present invention is intended to provide a pneumatic switch of simple construction which opens very fast, combining the beginning of opening by electrodynamic means with an accelerated continuance of the opening movement under the effect of a compressed gas.

Its object is, more particularly, a pneumatic switch comprising a cut-out chamber containing a compressed gas and, in that chamber, a set of contacts whose moving contact is installed 'on a moving rod crossing through a wall of the said chamber. The switch is characterized in that the said moving rod is hollow at least throughout the whole of its length entering the said chamber, the inside of that rod communicating, through an opening in the portion of the rod outside the said chamber, with a low-pressure medium, and has, installed round the moving contact, the body ofa valve which, when the switch is in the closed position, is closed and separates the inside of the said rod from the compressed gas contained in the said chamber. Electro-dynamic means, placed on the outside of the said chamber, cause, when they receive a current emission, the beginning of the opening movement of the said moving rod, and, subsequently, the opening of the said valve, this causing the accelerated continuance of the opening movement of the said moving rod under the action of the compressed gas contained in the said chamber.

These electrodynamic means may, to great advantage, be constituted by two coils exerting, between them, a repulsion effort at the instant of the said current emission: a fixed coil through which the said current emission flows and a short-circuited coil fast with a moving part of the main contact and of the said valve.

Other characteristics and advantages of the invention will become apparent from the description of examples of implementing which will be given with reference to the accompanying diagrammatic figures.

BRIEF DESCRIPTION OF THE DRAWINGS These figures are cross-sectional views in the axis of the cut-out chamber of a pneumatic switch, with like numerals covering like components.

FIG. I is a partial, sectional view of a cut-out chamber with double axial blowing means and a contact at the end.

FIG. 2 concerns a variant of FIG. 1 in which the end contact is replaced by a finger type contact.

FIG. 3 is another variant of FIG. I.

FIG. 4 shows a cut-out chamber in which the contact opens by the action of two moving parts.

FIG. 5 shows a variant of the fluid-tight sealing system of a cut-out chamber of the type shown in FIG. 1.

FIG. 6 shows a cut-out chamber having a single axial blowing means.

DESCRIPTION OF THE PREFERRED EMBODIMENT In all these embodiments, the switch comprises a cutout chamber consisting of an annular tank 1 filled with a high-pressure gas and, on one side of that cut-out chamber, or on both sides of the latter, a low-pressure tank or

tanks

2 and 3.

Fluid-tight sealing between the tanks I and 2 is insured by a sliding seal 4. A valve 5, arranged in the tank 1, forms a seal between a fixed part 6 and a moving part 7 sliding in the seal 4.

The casing 8 of the tank I is at least partly insulating. The passing of the electric current through the tank I is insured by a contact 9 between a moving contact 10 fast with the part 7 and another contact which, in the example in FIG. I, is a semi-moving contact 11 at the end, on which the effort of a spring 12 is exerted.

The original opening pulse of the contact 9 is obtained by means of a fixed coil 13, exerting a repulsion effort on the short-circuited coil I4, fast with the moving part 7 by means of an insulating rod I5.

In the example shown in FIG. I, a current emission in the coil moves the contact I0 and the moving part 7 which respectively press against the contact 11 and the seat of the fixed part 6 by a few millimeters. The high-pressure of the tank 1 then suddenly exerts an effort on the section of the mobile contact 10 and accelerates the movement of the latter. The are which was set up between the contacts 10 and II is extinguished by the axial double blowing means, going from the tank 1 towards the

tanks

2 and 3 respectively, on the one hand, across the contact 10, a tube 16 formed in the moving part and an orifice l7, and on the other hand, across the contact 11 and a tube 18 crossing the fixed part 6. The compressed air contained in the

tanks

2 and 3 released into the atmosphere, slowly and with a rela tively slight noise by

means oforifices

19 and 20 having small dimensions. These orifices may be replaced by valves having a small cross-section connected with the control means and insuring draining during a contact closing operation. Such valves are ofa known type and have not been shown.

In the opening position, immediately after the cutting out, the voltage between contacts is maintained by the air at the average pressure resulting from the balance of pressures after the high-pressure tank has been relieved by the low-pressure tanks. On the outside, the voltage is maintained by the insulation of the chamber.

The closing of the contact is obtained by any means.

Resistors operating at the instant of closing or opening, and inserted by any method, as well as capacitors insuring the distribution of the voltage between chambers connected up in series, may be connected up in parallel with the cut-out contacts or outside the chamher.

In the variant in FIG. 2, the end contact 9 between the moving contact 10 and the semi-moving contact 11 in FIG. I is replaced by a contact 9 between the moving contact 10 and fixed contact fingers 2I. fluid-tight sealing being, as previously, insured by the valve 5 placed between the fixed part 6 and the moving part 7.

FIG. 3 is a variant of FIG. 1, in which the respective dimensions of the parts have been modified.

In FIG. 4, the device comprises two moving

contacts

22 and 23 forming an end contact 9 and comprising, respectively.

exhaust orifices

24 and 25 in the

low pressure tanks

2 and 3. Fluid-tight scaling is effected. as previously, by the valve 5. At the beginning of the operation, the moving contact 23 is pulled by the insulating rod 15, and after the opening of the valve 5, the two

contacts

22 and 23 are pneumatically accelerated by the high-pressure of the tank 1.

In FIG. 5, the sliding seal 4 in FIGS. 1 to 4 is replaced by a seat comprising a seal 26.

When the cut-out currents are lower, the double blowing means may be replaced by a single blowing means, as shown by FIG. 6. Inside the high-pressure tank 1, an end contact 9 is produced between the moving part 10 and the semi-moving contact 11 pushed by the spring 12. At the beginning of the opening, the insulating rod 15 exerts a traction effort on the moving part 10, opens the valve 5 and the high-pressure action pneumatically accelerates the moving part 10. The releasing of the compressed air of the tank 1 towards the single low-pressure tank 2, passing through the tube I0 and the orifices 17, causes the extinguishing of the arc.

The device has been shown in FIG. 6 with end contacts 9 and a sliding fluid-tight sealing means 4, but it may be provided with the arrangements shown in FIGS. 2 and 5.

The device which is the object of the invention is suit able for any voltages as a circuit-breaker and enables a very fast cancelling of defects. It may also be used in the synthetic test circuits for circuit breakers. In that case, that device insulates the high-voltage circuits, cutting off the discharge of the main capacitor battery in the case of further priming of the capacitor being tested at the passing through zero of the current. It then makes it possible to effect a further cut-out attempt on the following passing of the current through zero.

The high are voltages produced by that device may also be used in various directcurrent circuit cuttingout or switching configurations.

What is claimed is:

1. In a pneumatic switch comprising a cut-out chamber containing a compressed gas and, in that chamber, a set of contacts whose moving contact is installed on a moving rod crossing through a wall of said chamber, the improvement wherein: said moving rod is hollow at least throughout the whole of its length entering said chamber, the inside of said rod communicating, through an opening placed in the portion of the rod outside said chamber, with a low-pressure medium, the body of a valve being installed round the moving 5 contact which, when the switch is in the closed position, is closed and separates the inside of the said rod from the compressed gas contained in the said chamber, electrodynamic means being placed on the outstide of said chamber in juxtaposition to said rod and IQ acting directly thereon to cause, when they receive, a current emission, the initiation of movement of said moving rod, and subsequently, the opening of said valve, this causing the accelerated continuance of the opening movement of said moving rod under the action 15 of the compressed gas contained in said chamber, said chamber including a hollow body, defining said seat, said fixed contact being fitted within an opening within said seat with said seat opening leading outside said chamber, to a low-pressure medium, said cut-out chamber consisting of a first cylinder, said hollow body consisting of a second cylinder having the same axis and being of smaller diameter, said second chamber leading at said first end into said chamber, and a cylindrical tank which communicates with the outside atmosphere through an orifice having a small cross section and into which the second end of said second cylinder leads and being arranged at the end of said first cylinder, on the output side of said hollow body.

2. In a pneumatic switch comprising a cut-out chamher containing a compressed gas and, in that chamber, a set of contacts whose moving contact is installed on a moving rod crossing through a wall of said chamber, the improvement wherein: said moving rod is hollow at least throughout the whole of its length entering said chamber, the inside of said rod communicating, through an opening placed in the portion of the rod outside said chamber, with a low-pressure medium, the body of a valve being installed round the moving contact which, when the switch is in the closed position, is closed and separates the inside of the said rod from the compressed gas contained in the said chamber, electrodynamic means being placed on the outside of said chamber in juxtaposition to said rod and acting directly thereon to cause, when they receive, a current emission, the initiation of movement of said moving rod, and subsequently, the opening of said valve, this causing the accelerated continuance of the opening movement of said moving rod under the action of the compressed gas contained in said chamber, said cut-out chamber comprising a cylinder, the moving rod extending through the wall of said chamber on the axis thereof, a cylindrical tank communicating with the outside atmosphere through an orifice of small cross sec tion, and said opening within said rod outside said chamber opening up into said cylindrical tank, on the output side of the moving rod.

Claims

1. In a pneumatic switch comprising a cut-out chamber containing a compressed gas and, in that chamber, a set of contacts whose moving contact is installed on a moving rod crossing through a wall of said chamber, the improvement wherein: said moving rod is hollow at least throughout the whole of its length entering said chamber, the inside of said rod communicating, through an opening placed in the portion of the rod outside said chamber, with a low-pressure medium, the body of a valve being installed round the moving contact which, when the switch is in the closed position, is closed and separates the inside of the said rod from the compressed gas contained in the said chamber, electrodynamic means being placed on the outstide of said chamber in juxtaposition to said rod and acting directly thereon to cause, when they receive, a current emission, the initiation of movement of said moving rod, and subsequently, the opening of said valve, this causing the accelerated continuance of the opening movement of said moving rod under the action of the compressed gas contained in said chamber, said chamber including a hollow body, defining said seat, said fixed contact being fitted within an opening within said seat with said seat opening leading outside said chamber, to a low-pressure medium, said cut-out chamber consisting of a first cylinder, said hollow body consisting of a second cylinder having the same axis and being of smaller diameter, said second chamber leading at said first end into said chamber, and a cylindrical tank which communicates with the outside atmosphere through an orifice having a small cross section and into which the second end of said second cylinder leads and being arranged at the end of said first cylinder, on the output side of said hollow body.

2. In a pneumatic switch comprising a cut-out chamber containing a compressed gas and, in that chamber, a set of contacts whose moving contact is installed on a moving rod crossing through a wall of said chamber, the improvement wherein: said moving rod is hollow at least throughout the whole of its length entering said chamber, the inside of said rod communicating, through an opening placed in the portion of the rod outside said chamber, with a low-pressure medium, the body of a valve being installed round the moving contact which, when the swiTch is in the closed position, is closed and separates the inside of the said rod from the compressed gas contained in the said chamber, electrodynamic means being placed on the outside of said chamber in juxtaposition to said rod and acting directly thereon to cause, when they receive, a current emission, the initiation of movement of said moving rod, and subsequently, the opening of said valve, this causing the accelerated continuance of the opening movement of said moving rod under the action of the compressed gas contained in said chamber, said cut-out chamber comprising a cylinder, the moving rod extending through the wall of said chamber on the axis thereof, a cylindrical tank communicating with the outside atmosphere through an orifice of small cross section, and said opening within said rod outside said chamber opening up into said cylindrical tank, on the output side of the moving rod.