US2752453A - Circuit interrupter and counter therefor - Google Patents

Description

June 26, 1956 J. M. WALLACE 2,752,453

CIRCUIT INTERRUPTER AND COUNTER THEREFOR Filed Oct. 9, 1950 2 Sheets-Sheet 1 WITNESSES: v INVENTOR 547/ JomesMWolloce.

June 26, 1956 J. M. WALLACE 2,752,453

cmcun" INTERRUPTER AND COUNTER THEREFOR Filed on. 9, 1950 2 Sheets-Sheet 2 WITNESSES} INVENTOR LJames M. Wallace.

United States Patent CIRCUIT INTERRUPTER AND COUNTER THEREFOR James M. Wallace, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, lla., a corporation of Pennsylvania Application October 9, 1950, Serial No. 189,082

11 Claims. (Cl. 200-108) My invention relates generally to electric circuit interrupting devices, and it has reference in particular to line sectionalizing devices and a counting mechanism therefor.

Generally stated it is an object of my invention to provide a line sectionalizer that is simple and inexpensive to manufacture and is reliable and effective in operation.

More specifically it is an object of my invention to provide in a line sectionalizing device for utilizing a new and improved form of counter which is inexpensive to manufacture and is extremely reliable in operation over a wide range of currents.

Another object of this invention is to provide in a counting mechanism for a line sectionalizer, for utilizing an armature construction which permits the use of rings of magnetic material on a piston of a non-magnetic material to obtain accurately stepped operations thereof.

Yet another object of my invention is to provide an operation counter having an armature movable by magnetic attraction for pumping a fluid to obtain stepped counting operations.

Another object of this invention is to provide in an operation counting mechanism for utilizing a container of a non-ferrous material and yet provide for concentrating a magnetic field in a relatively narrow zone about the container for obtaining a locking relation with magnetic means inside the container.

Yet another object of my invention is to provide in an operation counter for a line sectionalizing device, for utilizing a single movable armature for actuating a fluid pressure operated piston in accurately stepped operations.

A further object of my invention is to provide an improved sectionalizing device of the type for disconnecting a faulty section of a circuit from a source. Said device comprises a switch and a counter disposed to operate each time an associated reclosing circuit breaker interrupts the circuit. After a predetermined number of operations the counter trips the switch while the reclosing breaker is open, and thus isolates its section of the circuit so that the breaker can reclose and stay closed.

These and other objects of this invention will become more apparent upon consideration of the following detailed description of a preferred embodiment thereof, when taken in connection with the attached drawing in which Figure 1 is a substantially central vertical section view of a line sectionalizer utilizing an operation counter embodying the principal features of my invention; and

Fig. 2 is an enlarged vertical section view of the counter shown in Fig. 1.

Referring to the drawing, it will be seen that a sectionalizer 17 is here shown as being enclosed within a metal tank 27, which is provided with an insulating liner 28, and which is surmounted by a top casting 29. This sectionalizer may be substantially similar to that described in detail in the copending applications Serial Nos. 106,886 and 106,887 (now Patent 2,697,149) of James M. Wallace and Andrew Edwards, and James M. Wallace and Alvin W. Ogg, respectively, which applications are r 2,752,453 Patented June 26, 1956 assigned to the assignee of the present invention. An incoming line enters through a bushing 31 which terminates inside of the tank. The circuit then continues, through a conductor 32 to a sectionalizer coil 19. From the sectionalizer coil 19, the circuit continues through a conductor 33 back underneath the bushing 31 for the incoming lead 15, and thence to the terminal 34 which constitutes one of the stationary contacts of the section-' alizer which are disposed to be engaged by a movable contact 20. Ordinarily, the sectionalizer has two bush ings, each with its lead passing through the bushing, and each bushing terminates, at its bottom, in one of the stationary contacts of the sectionalizer, but since the drawing shows an approximate central section through the sectionalizer, the second stationary contact is not visible. The movable contact is shown as a contactbar or bridge which presses up against the underside of the stationary contacts 34 and the other stationary contact (not shown) in the closed position of the sectionalizer, and which is lowered by gravity, to operate the sectionalizer, upon the relase of a pull-rod 36, which is shown in the form of an upwardly extending insulating tube.

The sectionalizer 17 can theoretically operate either in air, or in an insulating oil, or other insulating fluid. It is sometimes desirable for the counter 37 to operate in oil, as it involves dashpot or fluid-flow operation, as subsequently described, which is somewhat more difficult to obtain in air, with the necessary time constants. It is sometimes desirable to have the contacts 3420 also operating in oil. We have consequently illustrated our apparatus, by way of example, as having the counter 37 and the contacts 34-20 immersed in oil 40 which is contained in the tank 27.

A counter-and-lockout mechanism 23 is segregated, into its component parts, consisting of the counter 37 and the operating-mechanism 38.

The operating mechanism comprises a bellcrank trigger 53 disposed to support a lever 47 which is pivotally supported by a fixed pivot 48 in a frame 41, and carries a pivot 44 which comprises one of the terminal points of a lever 43. A toggle mechanism, including a lever 46 pivotally connected to the lever 43 by a pivot 45, and an operating-handle pivotally supported on the casting 29 by a pivot 61, comprises the other terminal point of support for the lever 43. The pull rod 36 is connected to the lever 43 by a pivot 42. A trigger 53 is pivotally mounted in frame 41 having a downwardly extending abutment-portion 56, and is adapted to be tripped when an upward movement of a trip-pin 57 of the counter 37 raises said abutment point 56 of the trigger, whereupon the linkage of the operating-mechanism permits the pullrod 36 and the movable-contact member 20 to drop freely in the opening operation of the mechanism. The trigger 53 is biased clockwise by a spring 58 to the position shown, where it is held by a projection 51 on the lever engaging the edge of frame 41.

The counter 37 is suspended from the top of the top casting 29, by means of a plurality of depending insulating supports or tubes 70, which support the base-frame 71 of the counter.

The counter proper 37 comprises a vertically disposed tube 72, which is preferably made of brass or other nonmagnetizable metal. The lower end of the tube is disposed to be closed by a plug 73 of iron or other magnetic material, while the top of the tube 72 is open. The series current-coil 19 surrounds a portion of the tube 72, intermediate between its upper and lower ends. Immediately above and below the coil 19 are two perforated magnetizable plates 74 and 75, respectively, both of which are perforated so as to surround the tube 72. The plates 74 and 75 serve as the two pole pieces of an electro- 3 magnetic circuit, the excitation of which is provided by the coil 19.

Inside of the tube 72 is a magnetizable core or armature 76, which is slidably movable, with a close fit of say perhaps 3 mils radial clearance, within said tube. The armature 76 normally extends partly above and partly below the level of the upper plate 74, being located by means of a shoulder 69 in the tube, while the plug 73 is disposed partly above and partly below the lower plate 75. Both the armature 76 and the plug 73 thus extend partly within and partly without the space between the two plates 74 and 75.

In accordance with an important feature of my invention, the armature 76 may comprise two relatively movable elements, namely, a core 77 of iron or other magnetic material having a cylindrical extension 78 at the upper end, and a movable cap or piston 39 of a non-magnetic material such as brass, closely surrounding the extension. Annular grooves 83 may be provided about the piston 80, in which may be disposed snap rings 85 of iron or other suitable magnetic' material to provide projecting ribs which are vertically spaced from each other by a spacing which is preferably approximately the same distance as the closable distance between the core 77 and the plug 73, or other such disposition which will magnetically lock the piston in its different stepped positions against unwanted vertical displacement or slippage. A snap ring 88 of magnetic material may be disposed in a groove 87 about the tube 72 in line with the plate 74 to assist in concentrating the magnetic flux between the plate and the rings 85. A compression-spring 79 is disposed between the core 77 and the plug 73, so that when the coil 19 is sufficiently energized, such as by a fault current, the core 77 is drawn downwardly towards the plug, storing up energy in the interposed compressionspring 79, as will be more fully described hereafter.

Both the core 77 and the plug 73 are provided with central bores 81, and the lower end of each of these bores is provided with an orifice closable by means of a ball-valve 82, so that the fluid which is entrapped within the closed lower end of the tube 72 resists any rapid downward movement of the piston 80, because of the closing of the ball-valve 82 in the plug 73, while the valves permit the free upward movement of the piston 80 and core 77. The entrapped fluid could be any gas r.liquid having the required viscosity in comparison with the mechanical clearances which are provided. The idea is to permit the respective core 77 and piston 30 to move freely upwardly, in a step-by-step motion, as will be subsequently described, while permitting them to drift back downwardly again, by fluid-leakage, at a very slow rate.

At the top of the armature 76 on the piston 30, is affixed an upstanding pin 84, which extends upwardly to a point above the open top end of the tube 72. This pin 84 is surrounded by a tubular tip or trip-pin 57, which is capable of serving as an adjustable vertical extension of the pin 84. This vertical adjustment is effected in any one of a plurality of vertical spaced positions corresponding to the spacing between the core 77 and the plug 73, by means of a cotterpin 86, so that adjustment may be made for any desired number of counts, such as 1, 2, 3 or 4, within the range of the counting-mechanism 37.

In the operation of the counting-mechanism 37, when the coil 19 is first energized with a current corresponding to the setting of the counter, the core 77 of the armature 76 is drawn downwardly toward the plug 73, so as to close the airgap which separates the inner ends of said armature and plug. The fluid between the core 77 and plug 73 cannot move downwardly, in order to permit the armature and plug to come together, because of the presence of the fluid-flow valve 82 in the plug 73, so the fluid between the armature and plug is forced upwardly through the check valve 82 in the core 77, and hence the piston 80 must move upwardly relative to the core 77 so that the piston tends to remain substantially stationary while the core 77 moves downwardly. The attractive force between the upper plate 74 and the upper magnetic ring is enhanced by the magnetic snap ring 88 on the tube 72, and the piston 80 is thus held securely in position as the armature 76 moves downwardly.

When there is a fault on the distribution line, within the protective reach of an automatic reclosing circuit breaker, the recloser-contact thereof quickly opens, and quickly again recloses, but during the moment (12 cycles or more, in a 60-cycle line) when said recloser-contact was open, the sectionalizer coil 19 is deenergized, re ducing the attractive force between the armature 76 and plug 73. The compression-spring '79 between the core 77 and plug 73 expands, and pushes the core upward again, to the normal separation-distance. During this action, however, fluid in the armature 76 is entrapped and cannot move downwardly, because of the fluid-flow valve 82 in the core 77, and hence the piston 80 and the core 77 must move upwardly together, which they are free to do, so far as fluid-action is concerned, because the lower valve 82 in the plug 73 will open during such movement. The magnetic attraction between the upper plate 74 and the corresponding magnetizable ring 85 of the piston 86 of the armature 76 is now practically nonexistent, because of the deenergization of the coil 19, and hence the piston 80 of the armature 76 is notched upwardly by a distance corresponding to approximately the amount of compression of the spring 79. Upon reenergization of the coil 19 above the rated value, the magnetic attraction between the rings 85 and 88 serves to accurately position the piston 80 and thus correct any undershoot or overshoot.

If a fault continues on the distribution system, at a point beyond the sectionalizer-coil 19, the reclosure of the recloser-contact reenergizes the sectionalizer coil 19 and causes a second compression of the spring 79, in a manner already described. If the fault is still on the system, as has just been assumed, the recloser-contact again opens, and a second upward stepping-movement of the trip-pin 57 is obtained. Thus the step-by-step movement of the counter-mechanism continues. The ring 88 about the tube 72, being of a magnetic material, acts to concentrate the magnetic flux in the gap between the plate 74 and the rings 85, thus increasing the effective locking power thereof, and accurately positioning the piston each time to prevent cumulative error.

When the last upward stepping of the piston 84} of the armature 76 is obtained, depending upon the vertical positioning of the trip-pin or tubular tip 57, this pin 57 comes into contact with the trigger 53 during this last upward movement, and trips out the sectionalizer-contact 20. It will be noted that this last upward movement of the trip-pin 57 occurs during a time when the current in the sectionalizer coil 19 is oif. In the operation of the recloser, the current remains off, that is, the reclosercontact remains open for a minimum of 12 cycles (on a 60-cycle line), before the recloser-contact recloses. The opening of the sectionalizer-contact 20 requires something like 2 or 3 cycles, so that it is seen that the sectionalizcr-contact 24 opens during the current-elf period, so that the sectionalizer-contact 2%) does not have to interrupt any substantial current.

By our new counter-mechanism, I have thus provided a counter in which the magnitude or distance of the advance-steps, by which the counter is advanced each time it counts, is accurately fixed. This action is obtained particularly by virtue of the inner magnetizable rings 85 of the piston of the armature 76, which magnetically interlock with the upper magnetizable plate 74 each time the coil 19 is energized, thus accurately lining up the vertical position of the piston armature, for each counting-operation. The outer magnetic ring 88 serves to concentrate the magnetic flux and increase the locking power of the rings 85. In this manner are avoided errors due to slightly difl'erent upward lifts, due to various conditions such as the magnitude of the fault-current, the other than normal position of the armature 76, which may be extending further outside of the coil one time than the other, so that there would normally be a tendency for the armature to settle itself into a central position with an extension beyond the confines if the coil 19, equal to that of the plug 73. My magnetic interlock also automatically adjusts for small amounts of drift, in case of a timed operation of the recloser-contact, which is sometimes used instead of the instantaneous tripping operations, as is well understood in the art. In short, I have provided a countermechanism which actually advances the trip-pin 57 by a fixed predetermined invariable amount, each time the coil 19 is deenergized, after having been energized sufficiently to compress the spring 79. The foregoing and other advantages are obtained in a structure which combines great simplicity, freedom from operational difficulties, and low manufacturing costs.

An important feature of my invention is related to the choice of brass or other non-magnetizable metal, as a material of construction for the tube 72 and piston 80, and the use of the rings 85 and 88 of a magnetizable material to effect magnetic locking. It is desirable to use a metal for said tube so that its bore can be accurately machined, so that close radial tolerances may be maintained between said bore and the armature 76. If a metal is used for the tube 72, it has to be non-magnetic in order to prevent sticking of the armature thereto and to permit the magnetic flux to penetrate to the armature 76 and plug 73. The use of the magnetic ring 88 permits a sturdy thick-walled tube to be used, and yet retain a limited air gap between the plate 74 and the core 77. The rings 85 permit magnetic locking of the otherwise non-magnetic piston. The piston and core assembly permits accurate tolerances to be more readily maintained on easy to machine surfaces, and the single movable armature construction reduces the number of accurately machined parts required.

The coil 19 surrounds the tubular insulating member 90. A return-path for the magnetic flux is sometimes provided by one or more magnetizable bolts 91, which join the upper and lower plates 74 and 75, outside of the coil 19.

While I have illustrated my invention in but a single exemplary form of embodiment, which is now preferred, it is to be understood that the invention is susceptible of considerable modification, by way of additions, omissions and substitution of various equivalents, without departing from the essential spirit of my invention, particularly in its broader aspects. It is desired, therefore, that the appended claims shall be accorded the broadest construction consistent with their language.

I claim as my invention:

1. A resetting electromagnetic counter comprising: a tube; an electromagnetic circuit having two spaced magnetizable pole-piece plates, each having an opening at least partially surrounding said tube; two normally spaced armatures, only one of which is slidably movable, and the other of which is fixed in the tube adjacent one end thereof, said movable armature carrying a relatively movable piston-like operating member, each of said armatures at some time extending partly within and partly without the space between the two plates, each of said armatures having a fluid-flow passage therethrough and each having a valve for closing said passage so as to resist rapid fluidflow through said passage in a direction out of the end of the tube having the fixed armature; a compressible spring between the two armatures, the operating member of the movable armature being biased toward the fixed armature for resetting said operating member so as to be ready for another counting-operation, said movable armature being movable in response to overloads and the cessation of overloads to pump a measured amount of fluid against the operating member, and magnetic detent means on 6 said operating member cooperative with one of said plates to magnetically position said operating member.

2. A step-by-step movable counter comprising: a tube; an electromagnetic circuit having two spaced magnetizable pole-piece plates, each having an opening at least partially surrounding said tube; two normally spaced armatures only one of which is slidably movable, with a close fit, within said tube, in a fluid the other being fixed relative to the tube to substantially close one end thereof, each of said armatures at some time extending partly within said partly without the space between the two plates; each of said armatures having a fluid-flow passage therethrough, and each having a valve for closing said passage so as to resist rapid fluid-flow through said passage in a direction out of the fixed armature end of the tube; at least one of the armatures having a relatively movable piston-like operating member with a plurality of annular magnetizable ribs which are vertically spaced from each other; and a compressible spring between the two armatures; the operating member of the movable armature being biased toward the fixed armature for resetting said operating member so as to be ready for another counting-operation, said movable armature being movable in response to overloads and the cessation of overloads to pump a measured amount of fluid against the piston-like operating member.

3. An operation counter comprising, an electromagnetic circuit including two spaced perforated plates of magnetic material having aligned openings therein, a tube of non-magnetic material disposed in said openings, a fluid in said tube a fixed core of magnetic material disposed to substantially close one end of the tube, an additional core of magnetic material slidably disposed in the tube, each of said cores having a fluid passage with a valve to resist passage of a fluid therethrough in the direction of the fixed core, biasing means between the cores, and a piston of non-magnetic material disposed slidably of the movable core to substantially close the bore thereof at the end remote from the fixed core, said piston being provided with a magnetic detent locking means of a magnetic material spaced axially of the tube, and said additional core being movable in response to overloads and cessation of overloads to pump a measured amount of fluid against said piston.

4. An operation counter comprising, an electromagnetic circuit including a coil and two spaced pole pieces of magnetic material having aligned openings therein, a tube of non-magnetic material for containing a fluid disposed in said openings and having a peripheral groove aligned with one of the pole pieces, magnetic locking means disposed in said groove, a fixed armature of magnetic material disposed to substantially close the end of the tube adjacent the other pole piece, a movable armature of magnetic material slidably disposed in the tube, a piston of non-magnetic material slidably disposed on the movable armature for movement axially of the tube in response to movement of the fluid by the movable armature in one direction and having a plurality of spaced peripheral grooves axially of the tube, and magnetic locking means disposed in said grooves.

5. In a circuit interrupter, separable contact means, operating means normally operable to maintain said contact means in contact making engagement, said operating means including trip means operable to release the operating mechanism and effect separation of said contact means, a counter including a coil connected in a circuit at line potential and having an electromagnetic circuit and relatively movable core members of magnetic material disposed in a fluid in a tube of non-magnetic material, biasing means disposed between said core members, each of said core members having an axial fluid passage with valve means closing said passage to resist rapid fluid flow in one direction, a piston slidably disposed on a movable one of the core members for actuating said trip means after a predetermined number of counting operations in response to movement of the fluid by the movable core 7 member, and magnetic detent means on said piston for positioning it.

6. An operation counter comprising, a tube containing a fluid, a coil surrounding a portion of said tube, an armature of magnetic material so disposed in the tube as to be drawn at least partly into the portion surrounded by the coil from an initial position when the coil is sufli ciently energized, a spring biasing the armature against such movement to return the armature to said initial position when the energization of the coil is reduced from such value, valve means for effecting a pump action by said armature to advance a measured amount of fiuid when the armature returns to said initial position, a piston of non-magnetic material disposed to be advanced by said pump action of the measured amount of fluid, and spaced magnetic elements on the non-magnetic piston cooperative with magnetic flux from the coil to accurately determine the amounts of said advancements.

7. In an operation counter, a tube containing a fluid, a coil surrounding at least a portion of said tube, an armature of magnetic material slidably disposed in said tube at least partly within the region of the coil, one way fluid valves in the armature and one end of the tube, a spring biasing the armature against further entry into said region of the coil, a movable piston of non-magnetic material disposed in the tube on the opposite side of the armature from the end of the tube having the valve, said movable armature being movable in response to overloads and cessation of overloads to pump a measured amount of fluid against the movable piston, and a plurality of separate rings of magnetic material arranged in spaced grooves :along the piston to cooperate with magnetic flux from the coil and assist in locating the piston in the tube.

8. A circuit interrupter comprising, fixed contact means, movable contact means adapted to be moved into and out of engagement with said fixed contact means, manual operating means for said movable contact means including a releasable mechanism, and an operation counter including a tube having a coil disposed about it connected at line potential and a movable armature of a magnetic material therein in a fluid with a non-magnetic piston movably mounted thereon, said movable armature being movable in response to overloads and the cessation of overloads to pump a measured amount of fluid against the non-magnetic piston for actuating said releasable mechanism in response to movement of the piston by the armature, and said non-magnetic piston having spaced rings of a magnetic material disposed about the piston to provide spaced position locking means.

9. An electromagnetic circuit comprising, a tube of nonmagnetic material containing a fluid, a coil disposed about said tube, a pair of core-members of magnetic material mounted for relative axial movement within said tube in the electromagnetic circuit, at least one of said coremembers being freely movable in either direction, pistontion, and means between the core members normally biasing said core-members apart so as to normally have a predetermined separation in which each core-member at some time extends at least partially beyond its end of said electromagnetic circuit, said movable one of said coremembers being movable upon predetermined energization of said coil relative to said other core member in said one direction against the bias of said core-separating biasingmeans, and returnable to said predetermined separation upon a subsequent deenergization of the coil of said electromagnetic circuit by said biasing-means to pump a measured amount of fluid against said operating means to advance it a predetermined distance upon deenergization of the coil in the opposite direction to said one direction.

10. An operation counter comprising: a tube; a pair of armatures of magnetic material disposed within said tube in a fluid, at least one of said armatures being slidable in said tube with a relatively close fit, unidirectional valve means providing a fluid passage in each of said armatures axially of the tube, biasing means disposed between the arrnatures, a coil surrounding the tube and at least a portion of said armatures, and a piston-like operating member in the tube on the side of the movable armature remote from the other armature, magnetic detent means disposed in spaced relation along said operating member, said movable armature being movable back and forth in the tube in response to overloads and cessation of overloads to pump a measured amount of fluid against the operating member on cessation of overloads to advance the operating member.

11. A switch comprising, separable contacts biased to open, latch means holding said contacts closed, an operation counter having a tube with a fluid therein and a solenoid winding thereon connected in series with said contacts at line potential, a movable armature of magnetic material disposed in the tube, and a piston-like part of non-magnetic material disposed in the tube on one side of the movable armature, one-way valve means in the armature, said armature being movable in response to overcurrents and interruptions thereof to pump a measured amount of fluid against the piston-like part to progressively advance said part in response to closely successive interruptions of overcurrents through said solenoid winding, an insulating support locating the counter for actuating the latch, and magnetic detent means for effecting more uniform advancement of said part under varying overcurrent conditions including a plurality of separate snap rings of magnetic material disposed in spaced grooves along said non-magnetic part in predetermined spaced relation corresponding to the desired advancements.

References Cited in the file of this patent UNITED STATES PATENTS 1,982,986 Garlington Dec. 4, 1934 2,337,713 Garlington Dec. 28, 1943 2,452,233 Gerard et a1 Oct. 26, 1948 2,457,681 Keating et al Dec. 28, 1948 2,490,987 Van Ryan Dec. 13, 1949 2,515,530 Schindler July 18, 1950 2,548,079 Thompson et a1 Apr. 10, 1951

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