US2883493A - Circuit interrupter device - Google Patents

Description

3 Sheets-Sheet l INVENTCR. HERMAN U. STUEL TIN@ BY Aprll 21, 1959 H. o. sToELTlNG CIRCUIT INIERRUPIER DEVICE Filed Feb. 2l 1957 April 21, A1959 H. o. sToEL'nNG 2,883,493

CIRCUIT INTERRUPTER DEVICE Filed Feb. 21, 1957 5 Sheets-Sheet 2 INVEN TOR. HERMAN U- STOELTINFT H. o. STOELTING CIRCUIT INIERRUPIER DEVICE lApril 21, 1959 Filed Feb. 2l 1957 3 Sheets-Sheet 3 IN VEN TOR. HERMAN U ETUEL TIN@ United States Patent CIRCUIT INinRRUPTER DEVICE Herman 0. Stoelting, Milwaukee, Wis., assignor to McGraw-Edison Company, Milwaukee, Wis.. a corporation of Delaware Application February 21, 1957, Serial No. 641,532

9 Claims. (Cl. 20G- 146) This invention relates to circuit interrupter devices and particularly to an auxiliary load break interrupter adaptable for use with conventional circuit making and breaking devices and which has an automatically and positively contact resetting means.

Auxiliary load interrupters are connected in shunt relation with the main circuit breaking device to momentarily accept the full load current when the main device 1s open and subsequently to interrupt that current within a confined area to extinguish any arcs established when the circuit opens. It is particularly advantageous to employ an interrupter unit which automatically opens in response to predetermined movement of the main circuit device and which is automatically reset before the main circuit device is again closed. For example, an interrupting device of this type is shown in the copending application of Gerald L. Atkinson, Serial No. 427,557, filed May 4, 1954, and assigned to a common assignee with the present application, and issued as United States Patent 2,785,254.

It is important that the auxiliary contacts close completely so that when the main circuit is closed and again opened, the interrupter device will function to prevent arcing in the main circuit device.

Although the previously referred to application provides an improved load break interrupter, it employs the inertia of the parts to effect a resetting of the contacts and is not therefore positively reset. Further, the interrupter is mounted between the arms of the main circuit device and if the contacts do not completely close, the main switch may close suiciently to make contact but it will not be latched in. When the main switch blade is released, it will or may snap open and act as a conventional air breaker with resulting disastrous arcing.

In accordance with the present invention, an auxiliary interrupter unit is pivotally attached to the main circuit control device and folds and unfolds relative thereto. A latch or link means interconnected with the interrupter unit and the main control device positively closes the arcing contacts within the interrupter unit when the latter is returned to a normal position relative to the main circuit controlling device. Biasing means are preferably connected with the main circuit breaking device to bias the interrupter unit to a normal position with respect to the main control. Releasable holding means maintain the biasing means inoperative until a predetermined movement of the main circuit breaker device occurs.

The accompanying drawings illustrate the best mode presently contemplated by the inventor for carrying out the invention.

In the drawings:

Fig. l is a plan view of a circuit interrupting device incorporating one embodiment of the present invention;

Fig. 2 is a side elevational view with parts broken away 2,883,493 Patented Apr. 21, 1959 lCe to more clearly show the position of the various elements in a normally closed position;

Fig. 3 is a view similar to Fig. 2 with the main switch open and the auxiliary switch in a position just prior to opening; and

Fig. 4 is a View after the main switch and the auxiliary switch open.

Referring to the drawings, the illustrated embodiment comprises an auxiliary interrupter switch 1 pivotally mounted on a main circuit maker and breaker 2 and electrically connected in parallel therewith to provide parallel conducting paths between a pair of spaced circuit terminals 3 and 4. A releasable latch member S holds the interrupter switch 1 closed until after the main switch 2 opens. The terminals 3 and 4 are adapted to be connected in an electrical circuit through any suitable means, not shown.

The main switch 2 includes a pair of transversely spaced switch blades 6 which are pivoted at one end to a hinge contact 7 secured to terminal 4. The hinge contact 7 is generally channel-shaped with the base 8 secured to the terminal and the side arms 9 projecting perpendicularly therefrom. A bolt or shaft 10 is secured within the upper portions of the side arms 9 and the switch blades 6 are journaled thereon. The opposite ends of the blades 6 are radially formed inwardly and disposed in slightly spaced relation of each other to provide a handle 11 releasably gripped by a jaw-type contact 12 secured to the other terminal 3. The jaw-type contact 12 is provided with resilient jaw members 13 projecting upwardly from the terminal 3 and which have their outer ends curved away from each other, as at 14, to provide entrance for the switch handle 11. The jaw members 13 are generally arcuate in cross section to provide a line contact with the blade. An eyelet 15 in the switch handle 11 allows the use of a conventional switch stick, not shown, to manually pivot the switch blades 6 about the hinge contact 7 in making and breaking the main circuit.

If the main switch 2 were the only switch in the circuit and were manually opened, an arc would be established between the switch blades 6 and the jaw-type contact 12 which would tend to destroy either or both of these members. The load interrupter 1 is adapted to momentarily carry the current during the opening of the main switch and has the ability to extinguish the arc set up within the interrupter unit.

The load interrupter unit is similar to that shown in the previously referred to copending application of Gerald L. Atkinson to which reference may be made for a more detailed description of the interrupter unit as such. The interrupter unit generally includes a non-conducting tube 16 having a conducting cylinder 17 rigidly secured to one end and a conducting tube 18 slidably journaled in a centrally apertured cap 19 closing the opposite end. A sliding plunger or rod 20 is journaled in the conducting tube 18 with a coil spring 21 concentric with the rod biasing the rod 20 and tube 18 to a retracted position. The rod 20 extends through an inner end closure 22 of tube 18 and into the cylinder 17 with a moving arc contact 23 threaded onto the end lof sliding rod 20 and normally held in engagement with a stationary arc contact 24 secured to a muflier 25 which in turn is secured concentrically within the cylinder 17. The arcing contacts 23 and 24 are releasably held in engagement by a leaf spring 26 which is secured `to the muffler 25 and extends into a detent 27 within an arc extenguishing rod 28 having a suitable electrically insulating surface which is threaded onto the inner end of rod 20. A stop 29 is secured to rod intermediate the length of the rod and is adapted to be engaged by the end closure 22 of the cylinder 17 upon predetermined relative movement of tube 18 and rod 20. Further attempted relative movement of the tube 18 with respect to rod 20 disengages the leaf spring 26 from the detent 27 and the coil spring 2.1 rapidly separates the arcing contacts 23 and 24.

ln the embodiment illustrated herein, the conducting tube 18 is releasably connected to the terminal 3 carrying the jaw-type contact 12 by the latch member 5, and the cylinder 17 is connected to the terminal 4 carrying the hinge Contact 7 through a pair of radially spaced arms 3G. The arms 30 are rigidly connected to cylinder 17 by the collar 31 and are pivotally connected to the switch blades 6 by a transversely extending shaft 32. When the main switch 2 is opened, the interrupter 1 pivots about the switch blades 6 and the tube 18 and rod 20 are extended relative each other and thereby maintain a conducting path between the terminals 3 and 4. This prevents arcing between the switch blades 6 and the jawtype contact 12.

The load interrupter unit 1 is disposed beneath the plane of the main switch blades 6 with the pair of arms extending upwardly at an angle from the collar 31. which is welded to the cylinder. The upper ends of the arms 3@ are journaled on the shaft 32 supported by the switch blades 6 in any suitable manner such as` by reduced end bearing portions 33 which are journaled within suitable openings in each switch blade. A pair of torsion springs 34 are wound on the shaft 32 and each have one end crimped over the upper edge of the adjacent switch blade 6, as at 35, and the opposite end crimped over the upper edge of the adjacent slanting arm 30, as at 36. The springs 34 act on the arms 30 to bias the interrupter unit 1 about the shaft 32 in a clockwise direction in the drawing.

Rotation about the shaft 32 is limited by a pair of insulating spacer arms 37 which are pivotably secured at one end on the hinge `contact shaft 10. The arms 37 extend forwardly and downwardly and are pivotally secured at their forward end on a shaft 38 which passes laterally through the latched end of the conducting tube 18 and is rigidly secured thereto to provide a link interconnecting the interrupter and the main circuit breaker. When the interrupter unit 1 is pivoted to a horizontal plane, the conducting tube 18 is fully retracted into the non-conducting tube 16 and further pivotal movement of the interrupter would require simultaneous pivoting of the spacer arms 37 about the hinge shaft 10 and also the supporting shaft 32 without relative movement of the tube 16 and y tube 18. Referring to Fig. 4, the pivotal paths of the spacer arms 37 from the hinge shaft 10 and from the suppont shaft 32 is shown by the respective phantom lines 39 and 48. As seen in Fig. 4, the pivotal paths cross at the shaft 38 and therefore the spacer arms 37 are locked against further rotation and hold the interrupter unit 1 in a plane immediately beneath main switch blades 6.

Referring to Figs. 2 and 3, when the main switch blade 6 is pivoted in an opening direction, the auxiliary interrupter unit 1 pivots about the lateral shaft 32 due to the holding action of :the latch or holding member 5 and unfolds with respect to switch blades 6. The latch member 5 is pivotally mounted to a base 41, as at 42, and the base is secured to the terminal 3 by suitable mounting bolts 43. The latch member 5 has a detent 44 within which the outer end of the conducting tube 18 is disposed when the main switch 2 is in a closed position. The latch member 5 is biased in a clockwise direction in the drawing and toward the conducting tube 18 by a coil spring 45 disposed between the base 41 and a flange 46 extending parallel to the base 41 and integrally from the upper end of the latch member 5. As most clearly shown in Fig. 3, when switch blades 6 are opened a considerable degree, the interrupter unit 1 is tilted upwardly. In this position, the conducting tube 18 is fully extended from the interrupter unit 1 and a flange 47 on the end closure 22 of tube 18 engages the end closure 19 of tube 16. Any further movement of main switch blades 6 is transmitted directly to ithe latch member 5 which will pivot backwardly and release the .tube 18. When the tube 18 is released, the torsion springs 34 exert a twisting force on the interrupter unit 1 and rotate the interrupter unit 1 in a clockwise `direction about the lateral shaft 32.

The interrupter unit 1, in rotating, simultaneously pushes the non-conducting tube 16 over the conducting tube 18 and draws or pivots the insulating spacer arms 37 upwardly in a clockwise direction about the hinge shaft 10. The spacer arms 37, in effect, exert a positive pull on the tube 18 to retract it into the interrupter unit. When the tube 18 is in a Ifully retracted position, the spacer arms 37 will lock and the interrupter unit 1 is again normally disposed beneath the main switch blades 6, as shown in Fig. 4. When switch blades 6 are again manually closed, the end of tube 18 rides down an inclined surface 48 on the top of the latch member 5, pivots the latch member in a counterclockwise direction and enters the detent 44 of the latch member.

In the illustrated embodiment of the invention, the auxiliary interrupter is in a completed parallel circuit with the main circuit breaker whenever the latter is closed. The interrupter may also normally be disconnected from the circuit and have initial movement of the circuit breaker complete the parallel circuit connection before the main circuit breaker is opened.

Although the present invention is described with a particular main circuit opening means, it may be applied to any other suitable circuit opening device such as the fuse cutout described in the previously referred to copending application.

The present invention provides a link means interconnecting the main circuit breaker and the auxiliary load interrupter to automatically and positively reset the arcing contacts in the interrupter.

Various modes `of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

l claim:

l. A load interrupter assembly having arcing contacts mounted on a load interrupter and adapted to be electrically paralleled with a main circuit breaker having an opened circuit position and a closed circuit position, which comprises means to pivotaflly mount the load interrupter `on the main circuit breaker, means biasing the load interrupter to a predetermined position relative to the circuit breaker lwith the circuit breaker in opened circuit and in closed circuit position, means to momentarily overcome said last named means and thereby relatively move the circuit breaker and the load interrupter during initial opening movement of the main circuit breaker, and rigid rod-like link means pivotally connected to the load interrupter and the main circuit breaker and adapted to positively dispose said arcing contacts to a corresponding position in response to the movement of said interrupter to `said predetermined position.

2. In combination, a main stationary contact, a main pivoting contact blade adapted to releasably engage said stationary contact, a lload interrupter adapted to be pivotally `attached to said contact blade and having an axially moving contact actuator with an arcing contact movable with respect to a relatively stationary contact in response to actuator movement, means biasing said interrupter to a predetermined position with respect to said Contact blade, folding means connected with said contact blade and said actuator to positively close the arcing contacts in response to the movement yof the interrupter to said predetermined position, and releasable means secured to said stationary contact and engaging said actuator to overcome said biasing means for predetermined initial circuit opening movement of the contact blade.

3. In combination, a main circuit maker and breaker switch having a pivotal conducting blade adapted to electrically connect a pair of spaced cincuit terminals, a load interrupter having a set of releasably engaged arcing contacts one of which is secured to an axially movable contact carrying assembly, said interrupter being pivotally secured in spaced relation to said conducting blade and having anormal longitudinal position extending longitudinally adjacent the conducting blade, and a rigid member pivotally secured to the blade and to the contact carrying assembly in spaced relation to the pivotal connection of the blade and member to positively close the arcing contacts in response to pivoting of the interrupter to said longitudinal position adjacent the conducting blade.

4. In an electrical circuit breaker, a movable contact releasably electrically engaging a relatively stationary contact, load interrupting contacts adapted to be connected in parallel circuit with said first named engaging contacts, actuator means adapted to open the load interrupting contacts in response to predetermined circuit opening movement of the movable contact, spring-loaded rigid rod-like link folding means continuously biasing the interrupting contacts to a closed position, and releasable holding means operatively associated with said last named means to operatively disassociate the last named means for the interrupting contacts until predetermined opening movement of said movable contact to allow separation of the arcing contacts, said holding means being released in response to further movement of fthe movable contact whereby said folding means recloses the arcing contacts.

5. In combination, a iirst line terminal, a second line terminal disposed in spaced relation to the lirst line terminal, a switch blade pivotally mounted on the first line terminal and adapted to releasably engage the second line terminal, a contact housing having a stationary contact and an axially movable contact disposed therein, means to pivotally support the 'housing on the switch blade in spaced relation to said rst line terminal and with the stationary contact electrically connected to the switch blade, conducting means including relatively axially movable members one of which is releasably attached to the second line terminal and another of which is attached to the movable contact, biasing means operatively associated with said last named means and said switch blade to pivotally bias the contact housing with respect to the switch blade, and rigid link means pivotally attached at one end to the switch blade and at the opposite end to said conducting means to hold the contact housing in a predetermined position relative to said switch blade against the biasing means, and adapted to positively close said arcing contacts with the housing in said predetermined position.

6. In combination, a main circuit breaker having a pivotal contact blade adapted Ito releasably engage a relatively stationary contact, an interrupter having relatively extendable members to maintain a circuit connection until a predetermined opening of said contact blade, one of said members being pivotally attached to said blade and the other of said members being releasably secured to said stationary contact, rigid link means pivotally secured at one end to the extendible member releasab'ly secured to said stationary contact and releasably engaging the stationary contact and pivotally secu-red at the opposite end to a relatively stationary member, and means rotatably biasing said interrupter about the pivotal attachment, said link means positively closing said arcing contacts with fthe interrupter and blade in a folded position.

7. In combination, a main circuit breaker havmg a switch blade pivotally supported on a line terminal and adapted to releasably engage a stationary contact member secured to a second line terminal, an auxiliary load interrupter having iirst and second arcing contacts releasably held in engagement and having relatively extensible conducting members one of which carries the first of the arcing contacts a second of which is adapted to be connected with the main circuit breaker, actuator means carried within said interrupter and biased in response to extension of said members to eiect rapid separation of said arcing contacts, releasable holding means secured to said stationary contact member and adapted to releasably hold the second extensible member, metallic extension arms rigidly secured to the interrupter and electrically connected to the second of said arcing contacts, said arms extending laterally from the second arcing contact and being pivotally secured intermediate the length of said switch blade to pivotally support the interrupter from the switch blade and electrically connect the interrupter in parallel with the main circuit breaker whereby said main circuit breaker may be opened without breaking the circuit, a spacer member pivotally secured at one end to the pivot support of the switch blade and at the opposite end to the free end of the second extensible member and locked against further pivotal movement with the interrupter lying in a plane parallel to said switch blade, and spring means operatively associated with the interrupter and the circuit breaker to bias the interrupter to said predetermined locked spacer position.

8. In combination, a main circuit breaker having a switch blade pivotally supported on a line terminal and adapted to releasably engage a stationary contact member secured to a second line terminal, an auxiliary load interrupter having first and second arcing contacts releasably held in engagement and having relatively extensible conducting members one of which carries the first of the arcing contacts a second of which is adapted to be connected with the main circuit breaker and having actuator means biased in response to extension of said members to effect rapid separation of said arcing contacts, releasable holding means secured to said stationary contact member and adapted to releasably hold the second extensible member, extension arms extending laterally from the interrupter to the circuit breaker and rigidly secured at one end and pivotally secured at the opposite end to pivotally support the interrupter, said arms including conducting means electrically connected to said arcing contacts and to said switch blade to electrically connect the arcing contacts in parallel with said main circuit breaker, spring means operatively associated with the extension arms to pivotally bias the interrupter, and a rigid spacer member pivotally secured at one end to the switch blade pivot support and at the opposite end to the releasably held extension member to hold the interrupter parallel to the switch blade against said spring means and positively close the arcing contacts.

9. An auxiliary load interrupter for a main circuit breaker having a switch blade pivoted at one end to a line terminal and releasably engaging a contact member rigidly secured to a second line terminal, which comprises a tubular housing of electrically insulating material, a conducting cylinder secured to one end of the housing, a conducting tube journaled in the housing and extending out of the end of housing opposite said cylinder, a conducting rod journaled in said tube and extending into said cylinder, arcing contacts with one contact secured to said cylinder and the other contact secured to said rod, releasable holding means operatively associated with the arcing contacts to releasably engage the arcing contacts, biasing means operatively associated with the conducting tube and rod and adapted to rapidly separate the arcing contacts after release of said holding means and biasing said rod into said conducting tube, conducting extension arms rigidly secured to said cylinder, said arms extending laterally from the cylinder and being pivotally attached to the switch blade intermediate said line terminals, latch means rigidly secured to said second line terminal and releasably engaging the end of the conducting tube, spring means operatively associated with the extension arms and the switch blade to rotatably bias the housing about the pivotal attachment of the extension arms, and insulating spacer arms pivotally secured at one end to the pivoted end of the switch blade and at the opposite end to the end of the conducting tube to hold the interrupter parallel to the switch blade with the conducting tube retracted Within said housing to positively close the arcing contacts.

References Cited in the le of this patent UNITED STATES PATENTS Harlow Dec. 28, 1943 Atkinson Mar. l2, 1957

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