US2636961A - Electric circuit breaker - Google Patents

Description

April 28, 1953 H N, sCHNElDER 2,636,961

ELECTRIC CIRCUIT BREAKER Filed Nov. 9, 1951 Invenbvw, Harold N. Schneiden,

mma/d@ His Attorneg.

Patented Apr. 28, 1953 ELECTRIC CIRCUIT BREAKER Harold N. Schneider, Springfield, Pa., assignor to' General Electric Company, a corporation of NewYorkv Application November 9, 1951; Serial No. 255,696

(ci. zooliisf 8 Claims; 1

This invention relates to electric circuit breakers and more particularly to circuit breakers of the huid-blast type wherein current-interrupting contacts are arranged in series relation to circuit-isolating contacts which are opened subsequent to the opening of the interrupting contacts. In circuit breakers of this type, a. resistor is frequently connected in parallel with the interrupting contacts sothat the resistor current which flows after opening `of the interrupting contacts must be interrupted by the isolating contacts. i y

Application Serial No. 2Gl,96l, of AAlbert Roxburgh et al., iiled December` 2 1, 1950, and application Serial No. 202,100,0f John W. Beatty, iiled December 21-, 1950,whichare assigned to the assigneeof thisinventionboth disclose and claim interrupters whereininterrupting contacts are connected in series withisolating contacts and wherein aresistor is connected in parallel with the interrupting contacts. Both the Roxburgh et al. and the Beatty applications are of the airblast type. Furthermore, both these applications disclose arrangementsV wherein three exhaust passages are provided for the removal of pressure gas supplied tothe interrupter. y p l Aprincipal object of this invention-is to pro- Vide an improved iluid blastjcircuit breaker'which is simple, compact and rugged in construction.

Another object of this invention isthe provision of an improved gas blastcircuit'break'er which is arrangedwith ammi-mum of'exhaust passages for the'dischargeo-gas to Yatmosphere so as to obtain optimum use ofthe pressure-gas without causing wastage thereof.

Still another object of this'invention is to -provide a gas blast circuit vbreaker-wherein ablast of gas supplied to the breaker may readily exhaust to atmosphere during aY circuit-interrupting operation through a pluralityof exhaust vpassages, and through at least one less exhaust passage after interruption ofthe circuit,lfthe reby toenhance the `conservation ofy pressure E gas.l

A -further object of this invention is the-provision of agas blast circuit breakerwhereinall parts are arranged inline-and Iwith all lthe-contact members contained within a-single compact enclosing structure.

The invention in one' form as applied toa gas blast circuit breakercomprises an enclosing structure in which is disposed Va tubular conducting member havingan interruptingcontact normally in engagement with oneend Athereof and having y a tubular isolating contact disposed in substantially` coaxial relation thereto `at the other Ving tubular member i.

4toward engagement with the upper end of a fixed end thereof. Bridging contact means may be arranged'normally to interconnect the conducting member electrically and also pneumatically with the tubular isolating contact so that these parts forman exhaust path for pressure gas supplied to the of the conducting member remote from the Visf'llating contact during the operationof the interrupting contact. ln'addition, iuid pressure responsive means may be vused to cause the bridging contact' means to operate after operation of the interrupting contact means so as to isolate the circuit and to prevent the exhaust of fluid through the tubular conducting member thereby to conserve the supply oi pressure gas.

The' invention both as toits organization and method of operationwillbe better understood from the following description taken in connection with the accompanying drawing in which thesingle iigure thereof is a cross-sectional view showing'av circuit breaker embodying the principles of the invention.

In" the drawing, the numeral l represents a tiibi'ilarv insulating casing iorming a portion'of the enclosingstructure or the circuit breaker. The tubular member l is mounted on suitable base structure la comparable to that shown and describedin the above-mentioned Beatty application Serial No. 202,106." The base structure la is provided with .a chamber lb which permits upward incoming blasts of gasoutside the chamber Iband'which forms' a downward exhaust path inside the chamber, both being indicated by arrows in'thedrawing. Secured to the upper end of tubular enclosing structure E is a metallic support member 2. Member '2 is aliixed to tubular'in'sulating member i by means of bolts 3 which eng'ageclamping ring l which in turn forces the wedge-shaped segments 5 into gripping relation with the upper end 'of insulating enclos- Mounted on the support member il is a closure cap member 6 which is secured toy member 2 by bolts which extend through sleeves il. Secured to the top 'surface of the'cover 6 is an insulating plate El and mounted'within the member c is a foraminated wall l which `acts in known marier to cool the products of an interrupting operation before the exhaust thereof in the direction of the arrows to atmosphere through the passage generally designated by the numeral l l.

Disposed within the support structure j a plurality of finger contacts i2 which are fiilcrumed at E3 to the base member 2 and whie are'bias'ed by'rn'e'ansv ef compressional springs l tubular conducting member i5 which is mounted within the insulating enclosing structure I by means of devices such as are indicated at Ita. A more detailed disclosure of the particular arrangement of the petal-type contacts I2 and parts associated therewith is set forth in application Serial No. 233,637, of John W. Beatty, filed June 26, 1951. The contacts I2 are moved out of engagement with the nxed tubular conducting member I5 by means of a blast of gas, such as air under pressure, which is supplied to the base structure Ia by any suitable valve means such as is disclosed in application Serial No. 233,542, of Ronald B. Shores, filed June 26, 1951, and assigned to the assignee of this application.

Connected between the support structure 2 and the member Iba, which is in electrical contact with the fixed tubular conducting member I5, is a shunt resistor I6. Thus it will be seen that once the finger contacts I2 are separated from the xed conducting member I5, a portion of the current through the circuit breaker fiows through the resistor It. After interruption of the arc, the current through the resistor must be interrupted by other means. As in the abovementioned Roxburgh et al. application, this resistor current is interrupted by means of a socalled isolating contact.

In the drawing, a suitable isolating contact is indicated by the numeral I'I. Disposed for cooperation with the isolating contact Il is a sliding contact or other suitable connecting means such as indicated schematically at I3 while a terminal I9 is provided on the support structure 2. Electrical contact between isolating contact Il and structure I5 is normally maintained by the bridging contacts 2&3. Thus the circuit through the interrupter comprises the terminal I9, member 2, finger contacts I2, fixed tubular conducting member E5, the bridging contacts 2G and the isolating contact I'I and the terminal I8. The current through resistor It is interrupted by the action of the isolating contact I1 separating from the bridging contacts 2t after the interruption of the arc drawn by the contacts I2. To this end the contacts 2@ are disposed within a cradle-like piston member 2l and are biased toward engagement with the conducting member I5 and the isolating contact Il by individual compressional springs 22. member 2I is operable within the cylindrical structure 23 and suitable bias for the piston 2| is provided in the form of a plurality of compressional springs 2d which are disposed about a plurality of guide rods 25 and which effectively bias the piston member 2I downwardly, the springs 2li being in engagement at their lower ends with a projecting shoulder 26 secured to the guide rods 25.

In order to control the upward movement of the piston member EI and parts associated therewith in such a way as to insure the separation of bridging contacts 2&3 from isolating contact I'I after interruption of the arc by the interrupting contacts I2, a suitable port 2l is provided in the cylinder wall 23 and a needle valve 23 is provided in the terminal member Iba. Thus when a blast of pressure fluid is supplied to the space between the insulating sleeve I and the isolating contact Il, the upward movement of piston member 2| is delayed sufficiently so that contacts 20 separate from isolating contact il after separation of interrupting contacts I2 from the tubular conducting member I5. The effect of port 2'! is to precharge with pressure fluid the The cradle-like piston space above the piston 2|, which fluid opposes the immediate formation of the isolating gap while the operation of needle valve 28 is such as to regulate the exhaust of pressure fluid from the space above piston 2i at a controlled rate for determining the time delay between interrupting and isolating. After, or coincident with, interruption of the resistor current by means of the contacts 2t, the isolating contact Il is moved downwardly. The particular apparatus for causing downward movement of contact is not shown in the drawing since such apparatus forms no part of the present invention. Suitable apparatus for this purpose is disclosed in the abovementioned application of Ronald B. Shores.

In View of the above description, it will be understood that, when pressure gas is supplied to the lower portion of tubular insulating member I in the space between that insulator and the isolating Contact Il, such pressure gas flows upwardly nrst to separate the interrupting contacts I2 from the fixed tubular contact I5 before the isolating contact Il' is drawn downwardly. Such pressure gas is exhausted upwardly through the cover member t and the opening I I in the direction of the arrows 23 and also flows downwardly through the tubular conducting member I5 in the direction of the dotted-line arrows 3D. The downwardly owing exhaust gas in tubular conducting member I5 iiows on through the space between the conducting member I5 and the isolating contact Il', thereafter through the isolating contact Il and to atmosphere through the ports 3d in base member Ia. Thus during this interrupting process, the pressure uid flows both upwardly and downwardly from the region surrounding the interrupting contacts I2. After the cradle-like piston 2i is moved upwardly so as to separate the contacts 2S from the isolating contacts I'I, the pressure from the source can flow into the space between the lower end of conducting member I5 and the upper end of isolating contact I I so as to oppose the flow of uid downwardly through the conducting member I5 from the interrupting contacts I2.

Accordingly, this new influx of blast pressure through the insolating gap will oppose or neutralize the downward exhaust flow through the fixed tube I5 from the main contact arc gap. More specifically, the downward exhaust flow represented by arrows 3 will be effectively opposed by the upward component of the isolating gap blast indicated by arrows 32 while the downward component of the gap blast represented by the arrows 3l follows the original exhaust path to atmosphere through the presently downwardly moving isolating tubular contact I1, which, in the next instant, may be assumed to be passing through a point in its opening movement represented by the dotted transient position 33.

Thus it will be seen from the above description that by the invention a substantial blast of gas is supplied to the interrupting contacts I2 during the interrupting operation due to the fact that two exhaust paths are provided; i. e., upwardly in the direction of the solid line arrows 23 and downwardly in the direction of the dotted line arrows 30. After the main arc is extinguished, the blast to the interrupting contacts I2 need no longer be high in magnitude. Thus this blast is reduced due to the fact that incoming pressure gas indicated by the arrows 32 iiows through the space between the isolating contact Il and the xed conducting member I5 to encounter the fluid tending to ow downwardly in conducting member I5 in the direction of the dotted line arrows 30. Thus the pressure across the ends of the xed conducting member l5 becomes substantially equalized to render ineffective one exhaust path and to reduce the total blast to the interrupting contacts. In this way, a substantial amount of pressure gas is conserved.

It will also be understood that by the invention, a compact and rugged arrangement is possible and that all the parts may be mounted in line in a single columnar structure which occupies a minimum of space.

Although the chosen embodiment described herein has featured a retracting isolating contact with pneumatic timing as constituted by the piston-carried contacts 2G; it will be understood that the movable isolating contact could abut, or telescope with, or engage tulip-type contacts mounted upon, the lower end of the xed tubular conducting member I5. In such a case, the opening instant of the isolating gap would be accomplished by mechanically timing the downward opening movement of the moving tubular contact I1.

From the above detailed explanation it will be appreciated that the invention essentially provides a continuous substantially open-ended, tubular, current-carrying structure which is made disjointable at two spaced points along its length to constitute a pair of series breaks. By enclosing these breaks in a common pressure-conning casing, and by arranging for the sequential opening of the breaks, the gas blast introduced to the `casing produces a double-exhaust arc-extinguishing blast at the break toward one end of the structure which, coincident ywith the opening of the other break, becomes limited to a single-exhaust scavenging blast.

While I have shown and described a particular embodiment of the invention, I do not wish to be limited thereto and intend in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. An electric circuit breaker of the duid-blast type comprising an enclosing structure, a plurality of hollow tubular conducting elements normally arranged in series conducting relation with each other and `defining a continuous hollow passage the extremities of which form uid exhaust passages, said elements being relatively movable during a circuit-opening operation so as to establish two gaps in sequence, said enclosing structure being arranged with respect to said conducting elements so as to enclose said gaps, and means for supplying a blast of fluid pressure to said structure, said fluid being exhausted in both directions through said hollow passage from the rst of said gaps to be established during a circuit-opening operation prior to the establishment of the second of said gaps, fluid pressure supplied to said second gap being in opposition to the flow of fluid through said hollow passage from the rst of said gaps to be formed to the second of said gaps to be formed.

2. An electric circuit breaker of the duid-blast type comprising an enclosing structure, a plurality of hollow tubular conducting elements normally arranged in series conducting relation with each other and defining a continuous hollow passage the extremities of which form fluid exhaust passages, said elements being relatively movable during a circuit-opening operation so as to establish two gaps in sequence, said enclosing struc- 6 ture being arranged with respect to seid conducting elements so as to enclose said sans, and means for supplying a blast of fluid pressure to said structure, the fluid pressure Supplied to the second of said gaps to be formed being in opposition to the flow of fluid from the first of said gaps to be formed through said hollow passage toward the said second of said gaps.

3. An electric circuit breaker of the fluidblast type comprising an enclosing structure, a xed tubular conducting member disposed within said structure, a movable tubular isolating ycontact disposed in said enclosing structure at one end of said xed conducting member and normally in conducting relation to said fixed conducting member, said isolating contact and said .xed conducting member forming an exhaust path for fluid supplied to the end of said `conducting.; member remote from said isolating contact, and fluid-actuated rneans operable in response to a blast oi fluid supplied to said enclosing structure electrically to separate said fixed conducting member and said isolating oontact and to establish communication between the incoming fluid blast and the space within said tubular conducting member at the end thereof adjacent said isolating contact thereby to oppose the exhaust of fluid through said tubulai` conducting member.

4. An electric circuit breaker or" the fluidblast type comprising a tubular enclosing structure, a fixed tubular conducting member disposed within said structure, a movable tubular isolating contact disposed in lspaced substantially coaxial relation to said fixed conducting member, fluid-actuated bridging means normally forming an electrical connection between said conducting member and said isolating contact, said isolating Contact and said fixed conducting member forming an exhaust path for pressure fluid supplied to said enclosing structure and to the end of said fixed conducting member remote from said isolating contact, said fluid-actuated bridging means being operable in response to said fluid to break the electrical lconnection between said fixed conducting member and said isolating contact and to establish communication between the incoming fluid blast and the space within said tubular conducting member at the end thereof adjacent said isolating Contact thereby to oppose the exhaust of fluid through said tubular conducting member, and means for preventing the completion of an operation of said fluid-actuated means until after openin--fr of said interrupting conta-ot means.

5. An electric circuit breaker of the duidblast type comprising a tubular enclosing structure, a fixed tubular conducting member disposed within said structure, interrupting contact means biased toward engagement with one end of said fixed conducting member, a movable tubular isolating contact disposed at the other end of said fixed lconducting member in spaced substantially coaxial relation thereto, uidactuated bridging means normally forming an electrical connection between said xed conducting member and said isolating contact, said isolating Contact and said xed conducting member forming an exhaust path for fluid supplied to said interrupting contact means after operation thereof, said fluid-actuated bridging means being operable in response to a blast of fluid supplied to said enclosing structure to break the electrical connection between said xed conducting member and said isolating con- 'tactl and to establish communication between the incoming iiuid blast and the space within said tubular conducting member at the end thereof adjacent said isolating contact thereby to prevent the exhaust of liuid through said tubular conducting member, and means for pre- Venting the completion of an operation of said fluid-actuated means until after opening of said interrupting contact means.

S. An electric circuit breaker oi the uidblast type comprising a tubular enclosing structure, a xed tubular conducting member disposed within said structure, interrupting contact means biased toward engagement with one end of said xed conducting member, a movable tubular isolating contact disposed in said enclosing structure at the other end of said xed conducting `member in spaced substantially colaxial relation thereto, bridging means normally forming an electrical connection between said xed conducting .member and said isolating contact, said isolating contact and said fixed conducting member forming an exhaust path for fluid supplied to said interrupting Contact means after operation thereof, means including a. piston and a cylinder operable in response to a blast of fluid supplied te said enclosing structure to break the electrical connection between said ;fixed conducting member and said isolating -contact and to establish communication between the incoming fluid blast and the space within said tubular conducting member at the end thereof adjacent said isolating contact thereby to oppose the exhaust of iiuid thro-ugh said tubular conducting member, and

means including regulating valve means anording communication between atmosphere and the surface of said piston means opposite to the working face thereof and a pcrt in a wall of said cylinder for admitting a portion of said blast to the surface of said piston opposite to the working face thereof for preventing the completion lof an operation of said fluid-actuated means until after opening of said interrupting contact means.

7. A fluid blast electric circuit breaker comprising an enclosing structure, a fixed tubular conducting member disposed within said structure, interrupting contact means disposed in said enclosing structure and biased into engagement with said tubular conducting member at .one extremity thereof, a tubular isolating contact disposed within said enclosing structur in coaxial relation to said tubular contact member at another extremity thereof and in spaced relation thereto, a fluid-responsive bridging contact means normally interconnecting said tubular conducting member and said isolating contact, said tubular conducting ymember and said tubular isolating contact forming a path for the exhaust of fluid supplied to said interrupting contact after the initiation thereby of opening movement of said interrupting contact and before disconnection of said isolating contact from said tubular conducting member by said huid-responsive bridging contact means in response to iuid supplied to said enclosing structure.

8. A fluid blast electric circuit breaker comprising an enclosing structure, a fixed tubular 'conducting member disposed within said structure, interrupting contact means disposed in said enclosing structure and biased into engagement with said tubular conducting member at one extremity thereof, a tubular isolating contact disposed within said enclosing structure in coaxial relation to said tubular contact member at another extremity thereof and in spaced relation thereto, and duid-responsive bridging contact means normally interconnecting said tubular conducting member and said isolating contact, said tubular conducting member and said tubular isolating contact forming a path for the exhaust of iiuid supplied to said interrupting contact after the initiation thereby of opening movement of said interrupting contact and before disccnnection of said isolating contact from said tubular conducting member by said fluid-responsive bridging contact means in response to iiuid supplied to said enclosing structure, fluid pressure in said tubular conducting member being substantially equalized after operation of said fluid-responsive bridging contact means so as to oppose the exhaust of fluid from said interrupting contact through said tubular contact member.

HAROLD N. SCHNEIDER.

References Cited in the le of this patent UNITED STATES PATENTS Name Date Wilcox May 4, 1948 Latour Mar. 11, 1952 Number

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