US2619562A - Circuit restorer - Google Patents

Description

Nov. 25, 1952 B. s. BEALL ETAL CIRCUIT RESTORER 2 SHEETSSHEET 1 Filed April 6, 1948 MEI.

Inver'wtors: Benjamin S. Beall John A Oppel, by

Their Attorrwey TIME NORMAL CURRENT NOV. 25, 1952 s BEALL ETAL 2,619,562

CIRCUIT RESTORER Filed April 6, 1948 2 SHEETSSHEET 2 Fig.2.

Inventors: Benj amin' S.BeaH, I John A.Oppe

Their Attorney.

Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE CIRCUIT RESTORER Benjamin S. Beall, Radnor Township, and John A. Oppel, Aldan, Pa., assignors to General Electric Company, a corporation of New York Application April 6, 1948, Serial No. 19,258

9 Claims. 1

Our invention relates to circuit interrupters and more particularly to operating mechanisms for circuit breakers of the automatically operable reclosing type. More specifically, our invention is an improvement on the operating mechanism disclosed in application Serial Number 19,364, filed April 6, 1948, McCurry et al., which is assigned to the assignee to whom this application is assigned. Our invention, furthermore, is related to application Serial Number 19,213, filed April 6, 1948, now Patent No. 2,597,024, dated May 20, 1952, Oppel, and to application Serial Number 19,340, filed April 6, 1948, Quinn, which are both assigned to the assignee to whom this application is assigned. Our invention is also related to application Serial Number 19,280, filed April 6, 1948, Wyman, and application Serial Number 19,249, filed April 6, 1948, now Patent No. 2,599,294, dated June 3, 1952, Thumim, both of which are assigned to the same assignee as this application.

In operating mechanisms for reclosing circuit breakers of the type disclosed in the abovementioned application of McCurry et al. in which provision is made for both instantaneous and time-delayed opening operations, it is possible that the time-delayed opening operations, though fully capable of proper functioning for moderately excessive fault currents, may be too prolonged where the magnitude of the fault current is of the order from, say, 15 to 30 times the normal full-load rating of the device. The above-mentioned application of Quinn discloses means for greatly decreasing the opening time of an operation, which normally would be timedelayed, provided the fault current is very large of the order of 15 to 30 times the normal full load current rating of the interrupter and thereby improves the possibilities of proper coordination between th recloser and fuses or other interrupting devices disposed in the line between the source of power and the particular recloser. The above-mentioned application of Oppel discloses means which further modifies the time current characteristic of a recloser to make possible better coordination between the recloser and fuses or other interrupting devices disposed between the recloser and the load centers.

In devices of the type disclosed in the above application of Oppel the parts which operate to convert what would be a substantially instantaneous opening operation as taught by the above Quinn application into a delayed operation for relatively high fault currents, the mechanism parts are rapidly accelerated and then are rapidly decelerated by a stop member. This decelcrating action imposes strains on the timing mechanism, the effects of which necessarily impose a limitation on the magnitude of current which can be interrupted without damage to the mechanism.

A principal object of our invention is the provision of an operating mechanism for electric circuit reclosers having improved time current characteristics.

A further object of our invention is to provide a reclosing circuit breaker such as that disclosed in the above application of McCurry et al. which has greatly improved time current characteristics without interference with the normal sequence of operations which eventually result in a final lock-out or lock-closed operation.

b17111 another object of our invention is to retain the advantages to be derived from the use of a recloser operating mechanism of the type disclosed in the above-mentioned application of Oppel and at the same time to provide such a mechanism with means for cushioning the mechanical strains imposed on the mechanism by fault currents of the order of, for instance, 25 or more times the normal rated current carrying capacity of the device.

A still further object of our invention is to increase the interrupting rating of automatically operable reclosing circuit breakers.

Still another object of our invention is to provide means for protecting operating mechanisms for automatically operable reclosing circuit breakers against the destructive effects which may result from a rapid deceleration of the parts of the mechanism.

Further objects and advantages of our invention will become apparent as the following description proceeds and the features of novelty which characterize our invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of our invention, reference may be had to the accompanying drawings in which Fig. 1 is a family of curves showing the time current characteristics of a reclosing circuit breaker embodying our invention as well as the time current characteristic curves of fuses which are coordinated with the recloser; Fig. 2 is an elevational view in section of a recloser embodying our invention; Fig. 3 is a schematic representation of the circuit incorporated in the reclosure shown in Fig. 2 and in which Fig. 4 is an enlarged elevational view of a small portion of Fig. 2.

In electric distribution systems it is desirable to obtain the maximum protection possible per dollar of investment in protective equipment. Frequently it proves feasible in a particular distribution system to combine automatically operable reclosing devices and fuses. Fuses may be inserted into the line between the source of power and the recloser and may also be placed in the line between the recloser and the load.

With reference to Fig. 1, the curve pq represents desired time-current characteristics of a recloser while the curve aib represents the time current characteristic of a reclosing device such as that disclosed in the above-mentioned application of McCurry et al. The curve az'j represents the time current characteristic of a device such as that disclosed in the above-mentioned application of Quinn. The curve az'kl represents the time current characteristic of a device such as that disclosed in the above application of Gppel. The curves 0, d and erepresent the time current characteristics of fuses inserted in the line between the source of power and the particular reclosing device. The longer time characteristics of the fuses will delay the operation thereof until the recloser will have had an opportunity to open the circuit. The curves 1, g and'h represent the time current characteristics of fuses inserted into the systemat points between the load centers and the particular recloser. The shorter time characteristic of this latter group of fuses will permit a particular fuse to blow and thereby disconnect the faulted load center from the system without causing the recloser to operate.

In accordance with the'above-mentioned application of Oppel means are provided for modifying the curve aij obtained with the device of the above-mentioned Quinn application by causing such curve to assume the shape aikl thereby avoiding the possibility of a failure of coordination between fuses having characteristics such as J, g and h and the time-delayed opening operations of the recloser.

In the mechanism disclosed in the above application of Oppel, the mechanism parts are accelerated rapidly and then decelerated very quickly by a stop member which cooperates with a time-delaying mechanism to produce the characteristic represented by the portion kl of the curve aikl. This rapid deceleration, due to the action of the stop member, imposes strains on the partsand thus limits the possible interrupting current rating of the device.

In accordance with our invention means are provided for modifying the curve aikl obtained with the device of the above-mentioned Oppel application by causing such curve to assume the shape ailcn. In this way good coordination between -the recloser and the fuses on the load side of the recloser having characteristics such as are represented by the curves .7, g and h is retained and at the same time strains on the mechanism parts for very high currents are considerably reduced.

The circuit shown in Fig. 3 comprises a pair of main contacts 1 and 2, a bridging member 3', and a main operating coil for opening the circuit through the main contacts I and 2 by moving the bridging member 3 out of engagement with the main contacts. A relay coil 5 controls the opening of normally closed relay contacts 6 and 1. One end 8 and the other end B of the circuit shown in Fig.3 are connected to the two terminals of the recloser, only one of which is shown in the'drawings and which is 4 designated in Fig. 2 by the numeral Hi. It will be seen that main operating coil 4 is short cir cuited by relay contacts 6 and l during normal service conditions and that relay coil 5 carries line current if main contacts I and 2 are in engagement with bridging member 3. Thus excessive current will activate relay coil 5 which will open its contacts 6 and 1 thereby placing main operating coil 4 in the circuit which will move the bridging member 3 out of engagement with contacts l and 2 to complete an interrupt ing operation.

With reference to Fig. 2 terminal l0 and the other terminal of the device, not shown, are both enclosed within insulators such as H which are mounted to the cover plate E2 of the de vice by means of adapter elements I3 and i4 and by the bolts 15. The operating mechanism is completely enclosed within a metallic tank I6 which has an insulating lining ll covering its inner surface. The tank 16 contains an insulat ing fluid. The cover 12 may be secured to the v tank It by any suitable means such as 'by a plurality of bolts which are not'shown. Formed into the flange E8 of the tank [6 is a peripheral groove IQ. A washer 29 is disposed within the groove 59 and bears against the flange 2| of the cover 12 to seal the tank and thereby to pre'-' vent the leakage of oil from within the tank [6 through the engaging surfaces of the flanges l8 and 2|.

It is evident from Fig. 2 that the operating mechanism embodying our invention depends from and is supported by the cover l2. The circuit breaker is supported ona distribution circuit pole or the likeby means of suitable studs or bands, not shown, which are welded or otherwise secured to the outer surface of the tank it. Thus it will be seen that the whole mechanism may be removed from the tank 16' by simply lifting the cover upwardly.

l or the purpose of supporting the mechanism, a substantially U-shaped supporting structure 25 is used. The supporting structure 25 incorporates thebase member therein which base member is secured by welding or otherwise to platel2. Since Fig. 2 is a sectional view, the base member 25 appears in section and the forward prong'of the U does not appear. At the lower edge-of each prong of the supporting structure 25, there is a projection 355 to which is bolted the supporting arms 2?. Secured to the lower ends of the arms 2? is the assembly generally indicated at'28. The

assembly 23 includes a supportin plate 29 to which the supportingarmszl are securedtby any suitable means such as the nuts 35. Securedto th supporting plate as by means of bolts such as 32 are a plurality of L-shaped members 3|. Secured to the L-shaped arms 3! are the laminated structures 33 and 35 which support the main operating coil winding i and the relay coil winding 5 respectively. Secured to the lower end of the laminations 33 and 3:3 is member 31 having'the projections 33. Secured to the member 31 there is shown the supporting plate -39 which is bolted as at 3 to the projections 33 of the member 57. The interrupting chamber generally indicated at t! comprises a lower plate d2 constructed of insulating material and the side wall 33 which also is constructed of insulating material. The plate E2 is supported by the bolts 64 and the supporting plate 39. Bolts 4 preferably should be insulated by any suitable means such as by the insulating sleeve 5. The main interrupting contacts I and 2 are disposed within the arcing chamber 4| and are supported on the bottom plate 42 thereof by means of terminal bolts 46 and 41. The bridging member 3 is secured to armature 48 by any semi-rigid construction which is adequate to achieve a wiping engagement and disengagement between the bridging member 3 and contacts I and 2. Suitably arranged oil expulsion ports I I2 are disposed in the walls of the arcing chamber ii. For the purpose of biasing the bridgin member 3 toward its closed position, the compressional spring 49 is used.

The relay contacts 6 and I are operated by the mechanism generally indicated by th numeral 56 in such a way as to delay the opening of the contacts 6 and 1 until the armature 5! of the relay has been moved upwardly to a point near the end of its opening stroke for purposes which will become apparent as the description proceeds.

The mechanism '55 incorporates th link 52 which is pivotally connected as at 53 to the relay armature 5i. The lower end of link 52 is pivoted at 54 to the member 55 which in turn is pivoted to a fixed member 56 secured to the arcing chamber wall 43 or which may be supported in any other suitable manner. It will be observed that the member 55 is constructed with the projection 51 extending along a portion of its upper edge and also that the member 55 is provided with an apertured projection 58 which serves as a means for mounting one end of the tension spring 55. Also pivotally mounted at 56 is a member 66. Disposed on the lower surface of the member 66 is an apertured projection 61 to which is attached the other end of the spring 59. Member 66 is also provided with a projection 52 which engages one end of the compression spring 63. The member 66 is also provided with a projecting pin 64 which engages a curved surface of the curved member 55 which is mounted to a fixed pivot L 66 which pivot may be secured to the wall 43 of the arcing chamber. Spring 76 serves to bias the member 65 for rotation in the counterclockwise direction against the pin 64 mounted on the member 66. It will be observed that the surface 61 of the member 66 engages the projection 51 on the member 55. The contact 4 is pivotally mounted at 56 and is provided with a recess 68 into which the projection 62 on the member 66 is movable. The bottom of the recess 68 affords a surface against which the small compression spring 63 is allowed to bear. The contact arm 1 is also constructed with a recess 69 which cooperates with the projection 61 on the member 66.

The operation of the delayed-action switch 56 is as follows: Whenever the relay coil 5 is sufficiently energized to impart upward movement to its armature 5!, the link 52 is elevated carrying with it the right hand end of the member 55. This motion of member 55 allows the projection 51 on the member 55 to move away from the surface 6'! of the member 65, and, as the member 55 is rotated counterclockwise about the pivot 56, the spring 59 is elongated and a counterclockwise moment is thereby exerted on the member 66. Member 60 is prevented from rotating in the counterclockwise direction, however, due to the engagement of the pin 64 on member 66 with the curved cam-like surface of the curved member 65. As the arm 52 continues upwardly, the forwardly projecting pin 54 eventually engages the curved member 65 and causes such member to be rotated in the clockwise direction about its fixed pivot 66. This clockwise rotation of the member 65 will cause the pin 64 to ride over the curved cam-like surface of the member due to the pull of tension spring 59 and will permit counterclockwise rotation of member 60 about fixed pivot 56. This counterclockwise rotation of member 66 will cause the contact arm 1 to be rotated counterclockwise due to the engagement of the projection El' on the member 66 with the upper edge of the recess 69 in the contact arm i. In this way the contacts 6 and '1 are separated thereby removing the short circuit from around the main operatin coil 4 which thereby causes the fault current to flow through coil 4 and initiates an opening operation of the bridging member 3.

When relay armature Si is allowed to descend as will be more fully explained hereinafter, the link 52 moves downwardly thereby causing the member 55 to be rotated clockwise. The projection 51 on the member 55, which is in engagment with the surface 61 of the member 66, causes the member 66 to be rotated clockwise about the pivot 56. The projection 6| on the member 60 causes the contact arm 1 to move clockwise about the pivot 56 and eventually causes the contact 1 to engage the contact 6. In the meantime the pin 64 on the member 66 will have moved downwardly along the curved surface of the member 65 to the position shown in Fig. 2.

It i apparent that the delayed-action switch 56 will maintain the contacts 6 and I in engagement during the initial portion of a circuit opening Operation and will permit the contacts to separate when the relay armature 5! has moved to a point very near to the end of its stroke.

The timing mechanism is generally designated by the numeral 12 which mechanism will now be described. The numeral 13 designates a fixed shaft which is supported at the front and rear by a journal engagement in projecting portions M which are formed integral with the downwardly extending arms of the generally U-shaped supporting structure 25.

As pointed out above, only the rear one of these downwardly projecting arms is shown and is in broken lines in the drawings. Rotatable about the shaft '13 is a ratchet wheel 15 which has notched portions l6 and 11 about its periphery and which also is constructed wit-h the smooth or unnotched portions 18 and 19. Also rotatable about the shaft 13 is a gear wheel 86 whose entire periphery is provided with gear teeth. The ratchet wheel 15 and the gear wheel 66 are interconnected by means of a spring mechanism as will be more fully explained hereinafter. Both the ratchet wheel 15 and the gear wheel 86 are provided with an arcuate slot 8| for a purpose which will be apparent as the description proceeds. Secured to the ratchet wheel 15 and rotatable about shaft 13 as a center point is a drum 82 on the periphery of which is wound a flexible cord 83, one end of which is afiiXed to some point on the periphery of drum 82 and the other end of which is tied to the tension spring 84. The opposite end of spring 84 is attached to aperture 65 in a down-turned portion of the supporting plate 26. The tension spring 84, as will be evident from the drawings, is adapted to exert a counterclockwise turning moment on the ratchet wheel 15 and is for the purpose of resetting the ratchet and gear wheels as will be more fully understood as the description proceeds.

The speed of rotation of ratchet wheel 15 and of gear wheel 66 is governed by an escapement mechanism which will now be described. Secured to the downwardly extending arm 25 of the. supportingsstructure. having the. base 26. is a shaft 90. Rotatable on shaft 99 is a. pinion III, the teeth ofwhich engage the teeth of the 'ear 83 at all times. Secured to the pinion SI and rotatable therewith is .a ratchet wheel 92 which cooperateswith the oscillatory escapement member 93'which is pivoted. at its center point to the pin 94 which pin is secured to the supporting arms 2-5.. Rotation of gear 3! will cause rotation of pinion 9|, ratchet wheel 92 and the interaction between the teeth of the ratchet wheel 92 and the projections of the oscillatory member S3will afford a time-delaying action in a manner well known in the art.

In ordertointer-relate the opening operations of' therelay armature 5| and the ratchetwheel I5, an opening pawl 98 is used. Pawl tt is pivot ally mounted at 9? .to the arm 98. A torsional springBS is usedto bias pawl'fib forrotation about pivot 9? in the clockwise direction so that, unless preventedfrom doing so, the pawl 96 will engage the periphery of the ratchet wheel '45. The arm 98 is U-shaped and the prongs thereof are pivotally mounted at their right hand ends on the shaftlt. ber' Hill by a pin Idi which is interposed between and secured to the front and rear prongs of the U-shaped member 93 and which pin is adapted'to ride in the arcuate slots Si in both the ratchet wheel and the gear wheel. The lower end or the member IE8 is pivotally connected to the armature EI by any. suitable means such as by the pin 35.

In order to cause the pawl 95 to become disengaged from the periphery of the ratchet wheel I5 when the arm dB is in the position shown in Fig. 2, a projection I32 is provided which is secured by any suitable means to a downwardly extending portion of one or both the arms of the U-shaped supporting structure 25.

For the purpose of inter-relating the closing operation of the armature t8 and the ratchet wheel I5 and the gear wheel 8%, a closing pawl I05 is provided. Pawl I65 is pivotally mounted to arm IIiS by any suitable means such as by a pin III'I. about pivot pin I6? in the clockwise direction by means of a torsional spring IE8. Arm IE6. i piv otally supported at its left hand end ontheshaft I3. In order to cause the pawl to move out of engagement with the periphery of the ratchet wheel I5 during a circuit closing operation, a pin I89 is provided which is supported by a downwardly extending portion of one or both the arms of the supporting structure 25. A link He is connected at its upper end to the arm Hi5 by the pin I07 and at its lower end a pivotable connection II I serves to connn'ect the link III? to the armature 48 which is disposed within the main opening coil 4.

For the purpose of automatically locking the interrupter contacts in the open position after the circuit breaker has performed a predetermined number of opening and closing operations, a linkage mechanism is provided which will now be described. An arm I I3 is rotatable about'the fixed shaft 98 and is 'apertured at its upper end for connection to the tension spring I It which biases the arm H3 for rotation in the clockwise direction. The arm I I5 is pivotally connected at its left hand end to the lower end of the arm I I3 by a pin HE. Arm H1 is'pivotally connected to the right hand end of the arms H5 and I06 by a pivotal connection to the pin I01. Arm H1 is provided with a slot H8 through which the pin The arm 98 is connected to the'mem- The pawl I 95 is biased for rotation I I9 is slidable. Pin I I 9 is'mountedoni an armfilifl which is pivoted at IZI to the sup-porting structure 25. A tension spring I22 is connected at its left hand end to the supporting structure 25 and berotated by the pin I23 in the counterclockwise:

direction about its supporting shaft against the action of the tension spring I'M. Thisaction causesthe link I I5 to be moved to the right. The slot H511 in link H5 accommodates the pin I II! and allows this motion to the right of'link 'I I5 to take place. Immediately following this motionto the right of link H5, link III! will be movedxupwardly due to the final opening operation-which will move the slotted link I'I'I upwardly. Movement to the right of link H5 together with upward motion of link I I9 causes the right hand end of link H5 to collide with pin I I9. This collision will rotate the arm I2il in the counterclockwisedirection about fixed pivot I2I. This movement of arm I2Il will move the spring I22 over center. The spring I22 will cause further counterclockwise movement of the armI 23 about its pivot I2I.

For the purpose of closing the main contacts after the breaker is locked-out and for the purpose of manually opening the main contacts, the arm I25 is provided which is pivoted to a fixed member I28. Opening I2? is incorporated-in the right hand end of the arm I25 and an opening I23 is incorporated in the left hand end of the member I25. If the breaker is closed and if it is desired to manually open the breaker, a rod having a hooked end is manually inserted into the opening I2? and then pulled downwardly. This downward motion of the right hand end of member I25 causes upward motion of the left hand end of member I25. When the'lower surface of the opening I28 engages pin H9, the link I II, the link I Iii, the armature -53, and the bridging member 3 are all elevated and the parts assume the contact open position and the device will be locked-open.

If the device is locked-open manually orautomatically, to close the contacts, it is only necessary to elevate the right hand end of the member I25 thereby rotating the arm I 20 in a clockwise direction about its pivot I2I which action permits the arm III, the arm H0, the armature 48 and the bridging member 3 to be lowered to close the contacts under the action of biasing spring 59. In order to cover the opening in the cover I2 through which the member I25 extends, we provide a covering shield I23.

It will be understood that the device could be adapted to perform, within limits, arelatively wide range of opening and closing operations wherein certain of these operations would be time-delayed and wherein certain others could'be made to occur almost instantly. For persistent faults the particular arrangement described above and shown in Fig. 2 is adapted to perform a first instantaneous opening operation followed by a time-delayed closing operation, a second instantaneous opening operation followed by a time-delayed closing operation, a third opening operation which is time-delayed followed by a third time-delayed closing operation, and a fourth opening operation which is time-delayed followed by a final lock-out operation.

Assuming that the interrupter is closed as shown in Fig. 2, a fault condition on the'circuit controlled by the device will cause an excess amount of current to flow through the relay coil which will immediately cause its armature 5I to move upwardly. As the armature 5I moves upwardly, the arm 90 will move clockwise about the shaft I3 and the pawl 98 will become disengaged from the projecting member I02. Torsional spring 99 will rotate pawl 96 in the clockwise direction causing the pawl to engage the smooth portion I8 of the ratchet wheel I5. Hence, pawl 96 will be free to slide along the ratchet wheel without appreciable impediment, and the armature SI and parts associated therewith will move rapidly in the upward direction. Near the end of the upper limit of travel of the armature 5I, the contacts 6 and 1 will open as previously explained, the short circuit around main operating coil 4 will thereby be removed and the main coil '4 will be forced to carry the full amount of the fault current. This current will cause the armature 48 to move rapidly upward against the bias of spring 49. Upward movement of armature '48 will elevate the arm I I 0 and in turn cause the pawl I05 to move upwardly in a counterclockwise direction with respect to the ratchet wheel I5. Bridging member 3 will move out of engagement with contacts I and 2 and the circuit will be interrupted. When this opening movement has progressed a slight distance, the pawl I05 will become disengaged from the stop I09 and the torsional spring I08 will rotate the pawl I05 in a clockwise direction about the pivot I0I. This clockwise rotation of pawl I05 will cause the pawl to engage the smooth portion I9 of the ratchet wheel I5 for a limited time. When the armature 48 has reached the limit of its upward travel, the pawl I05 will engage the toothed section I6 of the ratchet wheel I5. The bias of spring 49 together with the weight of the parts will automatically cause the armature 48, the bridging member 3, the connecting link IIO, pawl I05 and armature II5 to move downwardly. Because the pawl I05 is in engagement with the toothed section I6 of the ratchet wheel I5, downward motion of pawl I05 will cause clockwise rotation of the ratchet wheel I5 and the gear wheel 80. Rotation of gear wheel 80 will rotate the ratchet wheel 92 through the pinion 9| and time-delay will be achieved by the oscillatory motion of the member 93 about the perimeter of the ratchet wheel 92. Thus, the closing operation of the device will be time-delayed a predetermined amount. If the fault condition should have cleared itself, the bridging member 3 will remain in engagement with the contacts I and 2 and the ratchet wheel I5 and the gea wheel 80 will be rotated in a counterclockwise direction to the reset position as shown in Fig. 2 by the action of spring 84 and flexible lead 83.

Should the fault persist, however, another opening operation will be initiated. The smooth portion '18 of the ratchet wheel I5 is sufiiciently long to afford no opposition to upward opening movement of the opening pawl 93 during the second opening operation. The device, therefore, will open substantially instantaneously as previously described and will reclose with time delay as already described since the pawl I05 will still be operating on the notched section T6 of the ratchet wheel.

Should the fault condition persist after the second reclosing operation, the relay coil 5 will elevate its armature 5I but at a slower rate because the preceding two time-delayed reclosing operations will have been sufiicient to advance the ratchet wheel I5 in a clockwise direction to a point where the notched portion 11 of the ratchet wheel I5 will be presented for engagement with the pawl 96. Further upward motion of armature 5|, connecting link I00, arm 08 and pawl 96 will cause the ratchet wheel I5 and the gear wheel to rotate in a clockwise direction. This clockwise rotation rotates the ratchet wheel 92 through the pinion 9| and, as previously explained, timedelay will be achieved through the oscillatory action of the escapement member 93. When the armature 5I has reached a point near the end of its upward travel, the relay contacts 6 and I will be opened as previously described and main coil 4 will be energized thereby elevating bridging member 3 to open the circuit. The two reclosing operations performed with time-delay and the one opening time-delayed operation thus far described will not have been sufficient to advance the notched section I6 of the ratchet wheel 15 beyond the pawl I05 and so the pawl I05 will engage the notched section IG of wheel I5 and permit the main contacts to close with time-delay as previously described.

Should the fault still persist, the interrupter will open with time-delay as described above in connection with the third opening operation since the pawl 96 will still be in a position to engage the toothed section 11 of the ratchet wheel I5. Upon completion of this fourth and final opening operation, the pin I23 will have been advanced clockwise from the position shown in Fig. 2 to a position of engagement with the arm I I 3 and-the lock-out linkage will proceed to force the arm I20 over center to achieve final lock-out as already described. Briefly stated, the engagement of the pin I23 with the arm II3 causes counterclockwise rotation of the member II3 about its fixed supporting pin which operation is followed immediately by an opening operation which elevates the armature 48. The link I I5 then collides with the pin I I9 and rotates the member I20 to its locked-out position.

Means are provided for permitting the ratchet wheel I5 to rotate independently of the gear wheel 80, even though the pawl 93 is in engagement with the toothed section of the ratchet wheel I5, provided the fault current is in excess of a predetermined relatively large value. As is more clearly shown in Fig. 4, an arcuate slot I30 is provided in both the ratchet wheel I5 and in the gear wheel 80 which slots coincide when the mechanism parts occupy the positions shown in Figs. 2 and 4. Secured to the ratchet wheel I5 in the left hand end of the arcuate slot therein is a tab I3I which projects rearwardly into the slot I30 in the gear wheel 80. Secured to the gear whee1 80 in the right hand end of the slot I 30 therein is a tab I32 which projects forwardly into the slot I30 in the ratchet wheel I5. Disposed between the tabs I3I and I32 with its axis about midway between the rear surface of the ratchet wheel I5 and the front surface of the gear wheel 80, a collapsible member in the form of a precharged compression spring I 33 is provided. The spring I33 thus interconnects the gear wheel 30 and the ratchet wheel I5. The gear 80 is connected, as explained above, to the time-delaying oscillatory member 93. The spring I33 is so constructed and arranged as to be precharged a predetermined amount in such a direction as to exert a moment on the ratchet wheel I5 which tends to rotate that wheel in the counterclockwise direction and which exerts a moment on the gear wheel 80 which tends to rotate that wheel in the ll clockwise direction. The ratchet'andgear wheels arexmaintaine'd' in the positions shown in Figs. 2 and thy the tabs ISI' and I32 which engage the left and right hand ends of the gear and ratchet wheels respectively.

It will be-apparent that, if the counterclockwise moment exerted on the ratchet wheel -75 through the tab 131 by the spring I33 is of a proper value; the time-delayed opening operation of the pawl 9%, the link 18!], the armature 5! and the contact I will proceed with time-delay if the fault current on the line, and hence the force exerted. by coil'5', is: below a predetermined amount-and the gear wheel 80 and associated time-delaying mechanism will be operated.

Otherwise stated, the curve az'a' of- Fig. 1 will be the'sameras: the curve uib of Fig. l in so far'as the common portion oz of these two curves is concerned.

If, however, the fault current is of the order of a higher value than: indicated by the letter i the upward force exerted by armature 5 ithrough link I00 on pawl 435 'Will be sufiicient to overcome more rapidly the counterclockwise moment exerted by the spring l33 'on the ratchet wheel through the tab 1311 The ratchet Wheel, therefore; will be free to rotate in the'olockwise direction more rapidly while the gear wheel so and the associatedtime delaying mechanism will operate 'at'a rate corresponding to the force exerted by the spring 1'33. Otherwise stated, the characteristic curve of the recloser will follow "the line 17' rather than the 'line' ib due to the action of the parts thus far described.

The functional operation of the mechanism as thus far described is similar to that of the arrangement disclosed in the above mentioned application'offQuinn although the construction is difierent.

As: was pointed out above, it is desirable to provide good, coordinating possibilities between the particular'recloser and'the fuses or other'interrupting devices disposed in the line between the load centers and the particular recloser. Otherwise "stated, it is desirable to prevent the intersection of the curves f, g and h of Fig. l

withthe curve at of that figure. For this purpose the: portion k7" of the'ourve aia' may be caused to assume the position kl so that the recloser characteristic'curve for tim'e-delayedopening'will 2;

lowed to proceed without time-delay where the fault current is excessively high for Ia portion only "of "the upward motion of the pawl 95 and means-'arelprovided for introducing time-delay for the remainder of the upward opening motion of the pawl 96.

As is disclosed in the above-mentioned application of Oppel the time-delaying action represented by the-portiorrkl-of the curve az'lcl for the latter portion of an opening operation isaccomplished bysecuri-ng a stop member-to-thegear wheel 89 in such a way that the stop isdisposed in-the path of movement of the tab it! mounted on the ratchet wheel 15. When the tab 13! collides with thestop on the-gear wheel 88, the ratchet wheel :15 and thegear wheel 80 move in unison for the remainder of the opening rotation of those: wheels. This collision of the stop member on the gear wheel 88 and the tab I31 may result in a substantial shock to the parts of the-device. Also, at the higher currents the timing mechanism may be subjected to undesirably high opera-ting forces transmitted from armature 5|.

In accordance with our invention provision is madefor reducing substantially the magnitude of impact between the stop member on the gear wheel 8d and the tab 13 and for limiting the forces which can-betransmittedto timing mechanism 25. To this end the stop 1:34 is' mounted on the shaft 15'. The stop we is provided with a projection [35 Jior engaging the-tabl 3| and is also-provided with a'proiection. I38 which extends rearwardly through an arcuate slot It! in the ratchet wheel '15 and slot 13min the-gearwheel Bil. Secured in the lower .or right hand end of the slot 131a in the gear wheel -88 is a tab I38 which projects forwardly into" the slot 1 3Tin-the ratchet wheel i5; Disposed between the projection; I35 on: the stop we and the .tab'l38 is a compression spring l39-forimpartinga counterclockwise moment to thestop I34. Rotation of stop iM-is'limited bythe engagement ofthe projection 136 with the upper or leithandend of the slot 137a in the gear wheel. The force necessary to compress spring I39 should be greater than that required to compress spring [33 so that spring [39 will require ahigh'er current value for its operation than spring res.

Thus it'will' be understood that the ratchet wheel will movecloc'kwis'e whenf'ault currents are very high while the 'giear'wheel :cc remains substantially stationary until the tab 131 on the ratchet wheel collides Withthe projection [35' on the stop- [34. This collison occurs'without substantial shock due to the action of the heavy spring I39 which yields and is displaced by an amount dependent upon the magnitude of the fault current and the resulting force of the impact'between the tab 131 and the projection I35 on the stop we.

The effect on the time current characteristic of a recloser having an operating mechanism-such as that disclosed in the above-mentioned application of Oppel will. be to cause the portion kl thereof to, assume a position 7cm as shown in Fig. 1. It will beiapparent that coordination between theqrecloser and the interrupting devices, having the characteristics f, g and h is not impaired within the normal operating range of the recloser and that the shock to the mechanism/and the higher forces on the timing mechanism which otherwise result, aresubstantially reduced.

It .will also be apparent that the incremental angular displacement of the ratchet wheel 15,-.due

spects and we, therefore, intend in the appended claims to cover all-such changes and modifications as fall within the true spirit-andisoope. of our invention.

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

1. An operating mechanism for an electric circuit reclosing device having relatively movable contacts and adapted to perform a cycle of operations during persistent fault conditions comprising electromagnetic means for opening said contacts, a timing mechanism, means including a rotatable member engageable by an element connected with said electromagnetic means and responsive to preselected opening operations of said electromagnetic means and a collapsible member forming an operative connection between said rotatable member and said timing mechanism for interrelating the opening operations of said contacts with said timin mechanism, said collapsible member being operable to operate said timing mechanism to delay opening of said contacts during preselected opening operations of said device when the value of the fault current is below a predetermined amount, and means including a stop member resiliently mounted with respect to said timing mechanism and operable in response to movement of said rotatable member for causing said timing mechanism to delay opening of said contacts during the latter stages but not during the initial stages of such preselected opening operations when such current is in excess of a predetermined amount.

2. An operating mechanism for an electric circuit reclosing device having relatively movable contacts comprisin electromagnetic means for opening said contacts, means for imparting closing movement to said contacts, a timing mechanism, means including a rotatable member engageable by an opening pawl and a closing pawl connected with said electromagnetic means and respectively responsive to preselected opening operations of said electromagnetic means and to closing movement of said contacts and a collapsible member forming an operative connection between said rotatable member and said timing mechanism for interrelating the opening and closing operations of said contacts with said timing mechanism, said collapsible member being operable to operate said timing mechanism to delay operation of said contacts during closing operations of said device and also during preselected opening operations of said device when the value of the fault current is below a predetermined amount and during the final stages but not during the initial stages of such preselected opening operations of said device when the value of the fault current is in excess of a predetermined amount, and resilient means interposed between said timing mechanism and said rotatable mem ber for causing yieldable engagement between said rotatable member and said timing mechanism during the final stages of such preselected opening operations when the value of the fault current is in excess of a predetermined amount.

3. An operatin mechanism for an electric circuit reclosing device having relatively movable contacts comprising electromagnetic means for opening said contacts, means for imparting closin movement to said contacts, a timing mecha nism, means including a rotatable member engageable by a pair of elements operably related with said electromagnetic means and respectively responsive to preselected opening operations of said electromagnetic means and to closing movement of said contacts and a collapsible member forming an operative connection between said rotatable member and said timing mechanism for interrelating the openin and closing operations of said contacts with said timing mechanism, said collapsible member being operable to operate said timing mechanism to delay operation of said contacts during closing operations of said device and also during preselected openin operations of said device when the value of the fault current is below a predetermined amount and during the final stages but not during the initial stages of such preselected opening operations of said device when the value of the fault current is in excess of a predetermined amount, and resilient means interposed between said rotatable member and said timing mechanism for causing yieldable engagement therebetween during the final stages of such preselected opening operations of said device when the value of the fault current is in excess of a predetermined amount. 4. An operating mechanism for an electric circuit reclosing device having relatively movable contacts comprising electromagnetic means for opening said contacts, means for imparting closing movement to said contacts, a timing mechanism, means including a rotatable member engageable by a pair of elements connected with said electromagnetic means and respectively re sponsive to preselected opening operations of said electromagnetic means and to closing movement of said contacts and a collapsible member forming an operative connection between said rotatable member and said timing mechanism for interrelating the opening and closing operations of said contacts with said timing mechanism, said collapsible member being operable to operate said timing mechanism to delay operation of said contacts during closing operations of said device and also during preselected opening operations of said device when the value of the fault current is below a predetermined amount, and means including a yieldable mounted shock absorbing stop member on said timing mechanism operable in respon e to movement of said rotatable member for causing said timing mechanism to operate to delay opening of said contacts during the latter stages but not during the initial stages of such preselected opening operations when such current is in excess of a predetermined amount.

5. An operating mechanism for an electric circuit reclosing device having relatively movable contacts and adapted to perform a cycle of operations during persistent fault conditions comprising electromagnetic means for opening said contacts, a timing mechanism, means including a rotatable member engageable by means connected with said electromagnetic means and responsive to preselected opening operations of said electromagnetic means and a collapsible member forming an operative connection between said rotatable member and said timing mechanism for interrelating the opening operations of said contacts with said timing mechanism, said collapsible member being operable to operate said timing mechanism to delay operation of said contacts during preselected opening operations of said device when the value of the fault current is below a predetermined amount and during the final stages but not during the initial stages of such preselected opening operations of said device when the value of the fault current is in excess of a predetermined amount, and precharged spring means interposed between said timing mechanism and said rotatable member for causing yieldable engagement therebetween during the latter stages of such preselected opening operations of said device when :the 'faultcurrent is in excess of apredetermined amount.

6. An operating mechanism for an electric circuit reclosing device having relatively movable contacts and adapted'to'perform a cycle of operations duringpersistent fault conditions comprising currentre'sponsive means'for opening said contacts, a timing mechanismincluding a gear wheel, a ratchet wheel, means connected with said current responsive means and engageable with said'ratchet wheel tocause rotation there-2 of in response .to preselected-closely succeeding operationscf said means for opening said cont acts, a firstrprecharged' spring means interposed between saidgear wheel and said ratchet wheel, said, ratchet wheel andv said spring being opcrab-1e to operate said timing mechanism to delay opening of said-contacts during said preselected opening operations'of saiddevice when the value of the fault current is below a predetermined amount, a stop member adapted to be engaged by said ratchet wheel during such preselected opening operationsof said device to cause operation of said timing mechanism to delay opening of said contactsduring the latter stages but not during the initial stages of such preselected opening operations when the value of the fault current is in excess of -second predetermined amount; and'a precharged spring means disposed between said stop member and said gear wheel forabsorbing the shock due to engagement betweensaid ratchet wheel and said stop member and for'improving the operating characteristics ofsaiddevicasaid first and second precharged spring means being precharged so as to yield in response to diiferent applied forces.

7. Anoperating mechanism for an electric circuit reclesing device having relatively movable contacts, comprising current responsive means foropening said contacts-means for imparting closing movement to said contacts, a timing mechanism including a. gear wheel, a ratchet wheel, means'connected with said current responsive means and engageable with said ratchet wheel, to cause rotation thereof in response to preselected closely succeeding operations of said means for opening said contacts and in response tooperation of said means for imparting closing movement to said contacts, a precharged spring interposed between said gear wheel and said ratchetwheel, said ratchet wheel and said spring being operable to operate said timing mechanism to delay operation of said contacts during closing operations of said device and during said preselected opening operationsof said, device when the value of the fault current is below a predetermined amount, a stop member adapted to be engaged by said ratchet wheel during such preselected opening operations of said device when the value of the fault current isin excess of a predeterminedamount to cause operation of said timing mechanism to delay opening of said contacts during the'latterrstages but not during the initial stages of such preselected opening operations thereby to improve the operating charac- '16 teristics of said device, and resilient means. disposed between said gear wheel and said'stop member for absorbing the shock to the mechanism due to engagement between said ratchet wheel and said stop member.

8. An operating mechanism for an electric circuit reclosing device having relatively movable contacts comprising electromagnetic means for opening said contacts, a. timing mechanism, means including a rotatable member engageable by an element connected with said electromagnetic means and responsive to preselected opening operations of said electromagnetic means and a collapsible member forming an operative connection between said, rotatable member and'said timing mechanism for interrelating the opening operations of said contacts with said timing mechanism, a shaft for said rotatable member, a stop member pivotally mounted on said shaft and adapted to be engaged by said rotatable member upon collapse of said collapsible member due to fault currents in, excess of a predetermined amount to cause'operation of said timing mechanism, and resilient means disposed between'said stop member and said timing'mechanisrnf r absorbing the shock to the-mechanism due to engagement between'said rotatablememher and said stop member.

9. In an electric circuit reclosing device, rela-' tively movable contacts, means responsive to fault conditions for opening said contacts, an incrementally movable member, means connected with said means responsive to fault conditions and engageable with said member to causemovement thereof, a timing device, and thrusttransmitting'mea-ns interposed between said member and said timing device for causing said timing device to operate to delay opening of said contacts whenever said member is advanced during opening operations when the value of the fault current is below a predetermined value but not when the value of the fault current is in excess of a predetermined value, and resiliently mounted stop means operatively connected with said timing device and operable in response to advancement of said member for operating said timing device to delay opening of said'contacts a short time for high fault currents in excess of a predetermined value and for operating said timing device a relatively long time for relatively low fault currents in excess of such predetermined value.

BENJAMINS. BEALL. JOHN A. OPPEL.

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

UNITED STATES PATENTS Number Name Date 1,123,288 Hellmund Jan. 5, 1915 2,311,714 Thompson Feb. 23, 1943 2,464,303 Gesellschap Mar. 15, 1949 2,487,025 Matthews Nov. 1,1949

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