GB1583381A - Circuit interrupter - Google Patents

Description

(54) CIRCUIT INTERRUPTER (71) We, WESTINGHOUSE ELEC TRIC CORPORATION of Westinghouse Building, Gateway Center, Pittsburgh, Pennsylvania, United States of America, a company organised and existing under the laws of the Commonwealth of Pennsylvania, United States of America, do hereby declare the invention, for which I/we pray that a patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a circuit interrupter. The subject of this application is closely related to the subject of our copending application No. 15706/77. (Serial No. 1583382).

Vacuum circuit breaker apparatus are well known and also the operating mechanisms for actuating the vacuum circuit breaker contacts. Vacuum circuit breaker apparatus have the characteristic of relatively short contact movement during the opening and closing operation. This relatively short movement is advantageous in many respects and is largely possible by the fact that the arc is interrupted in a vacuum. It is also known that welds have a tendency to form on closed vacuum contacts. It is often difficult to break the weld in an opening operation. In addition, since the relative movement of the circuit breaker contacts is small, the tolerances of the movement linkages become important and in many instances critical. Usually this requires adjustment of the circuit breaker apparatus linkages in the field at the operating site for the circuit breaker apparatus prior to operation. Generally, the operating mechanism for the circuit breaker apparatus is separately manufactured and assembled away from the contact apparatus. Then the operating mechanism and contact apparatus are later joined and the critical adjustments are made at that time. Because of the previously described welds, it is often necessary to generate relatively high forces to break the welds during an opening operation. Since it is the operating mechanism which supplies the power for moving the linkages in the circuit breaker apparatus to break the welds the previously described forces often affect the interface region between the supports of the operating mechanism and the supports of the circuit breaker apparatus. The repeated application of these forces tends to misalign the operating mechanism relative to the circuit breaker apparatus and thus misalign the relatively critical alignment characteristics of the circuit breaker apparatus linkages. It would be very advantageous if a way could be provided to prevent the necessary forces of vacuum circuit breaker operation from misaligning the critical linkages necessary for proper circuit breaker operation.

The invention consists in a circuit interrupter comprising a pair of separable main contacts, a movable one of which is carried by a connecting rod which is connected with an operating mechanism by a linkage, actuation of the linkage serving to open and close said separable main contacts, the operating mechanism for actuating the linkage being mounted on a pair of spaced apart support members, a shaft of the said linkage extending between the spaced apart members, the operating mechanism having a cam shaft extending between the spaced apart members, the cam shaft carrying a cam engaged by lever means forming part of said linkage, the cam being provided with a crank pin actuating a member which effects stressing of a charging spring.

Because the operating mechanism and the said linkage shaft are disposed upon the same spaced apart support members, forces of operation which would otherwise tend to misalign the operating mechanism with time relative to the separable main contact mechanism do not operate to do so in the present invention because there is no separate discontinuous interface between the operating mechanism support and the separable main contact linkage supports.

The invention will now be described by way of example, with reference to the accompanying drawings in which: Figure 1 shows an orthogonal projection of a circuit breaker apparatus operating mechanism, partially cut away; Figure 2 shows an elevation in section of the cam shaft of Figure 1 with its associated attached members (not to scale with respect to Figure 1); Figure 3 shows an orthogonal view of the apparatus of Figure 1 from another point of view; Figure 4 shows a front elevation of the apparatus of Figures 1 and 2, partially in section; Figure 5 shows a section of the apparatus of Figures 1, 2 and 4 at the section line V-V of Figure 4 for the apparatus in a first operating position; Figure 6 shows a sectional view of the apparatus of Figures 1, 2 and 4 along the section line VI-VI for the first operating position described with respect to Figure 5; Figure 7 shows a view similar to that of Figure 5 but in a second operating position; Figure 8 shows a view similar to that of Figure 6 but in a second operating position; Figure 9 shows a view similar to that of Figures 5 and 7 but in a third operating position; Figure 10 shows a view similar to that of Figures 6 and 8 but in a third operating position Figure 11 shows a side elevation partially broken away of a vacuum circuit breaker apparatus and operating mechanism; and Figure 12 shows a sectional view of the apparatus of Figure 11 along the sectional lines XII-XII.

Figures 1 to 4 depict circuit breaker apparatus with an operating mechanism 10 comprising two parallel, spaced apart support members 12, of generally the same size and shape. The support members 12 comprise fastening tabs or flanges 1 2a at the upper rear portion thereof, 1 2b at the lower front portion thereof, and 12c at the upper front portion thereof. Disposed perpendicular to the parallel spaced support members 12 and generally protruding therethrough is a rotatable jack shaft member 14. Jack shaft member 14 has sets of generally equally spaced, securely fastened operating levers 16a, 16b, and 1 6c disposed thereupon for being rotatably moved when the jack shaft 14 is rotatably moved. Jack shaft 14 also has disposed thereon near the ends thereof, jack shaft rotational limiters 18 which may abut against stopping members (to be described hereinafter) for preventing rotational movement of the shaft beyond a certain angular position. The ends of the generally circular jack shaft 14 comprise bearing surfaces 20, the use of which will be described hereinafter.

There is provided in each of the support members 12 a generally semicircular notch 22.

In the semicircular notch 22 of the left-most member 12 as viewed in Figures 1, 3, and 4 is disposed a jack shaft half bearing 24. It is to be noted that the force which is supplied from the operating lever 16b against the jack shaft 14 is borne against the bearing 24 of the left-most member 12. This provides a deflection force or supporting region for the operating lever 1 6b which is relatively close to the operating member 16b. The latter arrangement tends to prevent substantial deflection of the shaft 14 at the longitudinal center thereof during opening and closing operations of the circuit breaker apparatus.

It will be noted that the rotational limits of travel of the shaft 14 are such that the bite portion of the half bearing 24 is sufficient to provide an adequate bearing surface for the force offered by the rotationa] movement of the operating lever 1 6b during a contact opening or closing operation. It will be noted that this allows for the provision of a bearing surface which need not completely enclose the jack shaft 14 and thus which significantly reduces the complication of installing the jack shaft 14 in the operating mechanism 10. It will be noted that no bearing is disposed or needed in the semicircular slot 22 of the right-most support member 12 as viewed in Figures 1, 3, and 4.

There is also provided a cam shaft 26 which extends through both members 12 in a transverse orientation thereto. The cam shaft 26 may rotate for providing appropriate circuit breaker operations.

By referring to Figure 2 specifically and Figures 1, 3, and 4 more generally, the geometric characteristics of the cam shaft 26 may be more clearly shown. In particular, cam shaft 26 comprises a circular center portion 26a. Circular portion 26a is borne or supported by circular bearings 27 in both of the support members 12. Consequently, cam shaft 26 may rotate in the bearings 27.

At either end of the circular portion 26a of the shaft 26 is a square or rectangularly shaped portion 26b on the left and 26b' on the right as viewed in Figure 2. The characteristic square or rectangular shape may be provided by milling the circular stock of the shaft 26 in the appropriate regions.

Alternatively the milling operation may be provided only along two parallel planes to provide parallel flats rather than four-sided square or rectangular geometric shapes for keying purposes. Furthermore, the ends of the key portions 26b and 26b' are machined and threaded at 26c to accept an appropriate nut or similar fastening device 38. On the left side as viewed in Figure 2, a cam 28 having an opening similar in cross-section to the geometric shape of region 26b is keyed onto the shaft 26 and bolted against the leftmost shoulder of the circular region 26a of the shaft 26 by turning the nut 38 on the threaded region 26c. In a similar fashion, in sequence, a closing latch 30, a ratchet 32, and a spring closing crank 34. are disposed upon the keyed region 26b' from the rightmost shoulder of the circular region 26a of the shaft 26 to the nut 38 which is disposed on the right threaded portion 26 as viewed in Figure 2. It is to be noted that the closing latch 30 and the spring closing crank 34 are keyed to the shaft region 26b'. However, the ratchet 32 is free to turn around the keyed region 26b'. The ratchet 32 is separated from the keyed region 26b' by an appropriate spacer 26d. The ratchet 32 is prevented from moving in a left-right direction with respect to the shaft 26 of Figure 2 by the disposition of the closing latch 30 and the closing spring crank 34. A hollow cylindrical shell 31 is provided between the members 12 for enclosing the circular shaft portion 26a and providing a lubricating region therefor.

As can be best seen by reference to Figure 1, a key 39 which protrudes from either side of the ratchet 32 picks up appropriate portions of the closing latch 30 and the closing spring crank 34 to move these latter two elements and the entire shaft 26 which is keyed thereto, once the free wheeling ratchet 32 has been rotated to the position shown in Figure 1.

It is also to be noted that the relative angular disposition of the protruding pin 39 with respect to the closing latch 30 and the closing spring crank 34 allows those latter two elements to rotate counterclockwise when necessary through a significant angular disposition without necessitating corresponding movement of the ratchet 32.

Referring to Figures 1, 3, and 4 once again, spring charging motor 40 and a shaft 42 for the spring charging motor 40 is shown.

Shaft 42 is disposed in and supported by the support members 12. Attached to the end of the shaft 42 which protrudes through the right-most support member 12 is an eccentric 44 to which is attached a driving pawl 46 by way of a pin 47. The driving pawl 46 is forced against the teeth of the ratchet 32 by the driving pawl spring 48.

There is provided a stopping pawl 50 for preventing the ratchet wheel 32 from rotating in the clockwise direction as viewed in Figure 1. The stopping pawl 50 is pivotally mounted upon a pin 52 and is forced against the teeth of the ratchet 32 by a stopping pawl spring 54. Pivotally disposed between the support members 12 and extending through the right support member 12 as viewed in Figure 1, is a closing release shaft 56. The protruding or extending right-most end of the closing release shaft 56 has been milled to remove a semicircular portion of the cylindrical volume thereof. As will be described hereinafter, closing release shaft S6 operates in conjunction with a closing solenoid and manual pushbutton 58 to be rotated through a certain angular range when a circuit breaker opening operation is desired. When not actuated to begin a circuit breaker closing operation, the angular disposition of the closing release shaft 56 is such that the closing latch 30 becomes locked against the right side of the closing release shaft 56 as viewed in Figure 1 due to the applied force of the closing spring as will be described hereinafter. To prevent counter clockwise motion of the shaft 26, the aforementioned cooperating characteristic of the closing release shaft 56 and the closing latch 30 will be described in more detail hereinafter with respect to other figures. Outboard of the support members 12 are complementary connecting rods 60. The connecting rods are oriented generally parallel to the predominant flat surfaces of the members 12.

The connecting rods 60 are attached at one end thereof to a closing spring yoke 62.

Disposed against the inner surface of the yoke 62 as viewed in Figure 1, are the ends of an outer coil dosing spring 64 and an inner coil closing spring 66. Disposed against the other ends of the two previously mentioned coiled springs 64 and 66 is a closing spring support plate 68 which is conveniently anchored in grooves or notches 70 in the support members 12. A closing spring guide rod 72 extends axially through the coiled springs 64 and 66. The guide rod 72 is threaded at both ends thereof.

One threaded end extends through an opening 73 in the yoke 62. The latter threaded end of the guide rod 72 has a complementary nut 74 threaded thereon (this arrangement may be best viewed by reference to Figure 6).

Likewise the other end of the rod 72 extends through a complementary opening in the spring support plate 68. The latter mentioned end has a complementary nut 75 threaded thereupon. The guide rod 72 as disposed in the operating mechanism 10 allows the yoke to move thereupon when the springs 64 and 66 are compressed or discharged while maintaining the latter mentioned spring in a generally workable disposition. The connecting rods 60 have enlarged openings at one end thereof for capturing a flanged pin 76 on the yoke 62.

The opening in the end of the rod 60 allows for slight angular displacement of the rod 60 relative to the yoke 62 during a charging or discharging operation of the springs 64 and 66. Disposed at the end of the right closing spring crank 34 as viewed in Figure 1, is a driving pin 77 (shown in section) which is captured by a notched opening in the other end of the rod 60, for thus disposing the rod 60 between the closing spring crank 34 and the yoke 62. (The latter arrangement is not shown in Figure 1 because of the necessity of simplicity of illustration but is similar to the arrangement shown in Figure 3 for fastening the rod 60 on the left to the cam 28.) As can best be seen by reference to Figures 1 and 3, the left-most connecting rod 60 as shown in Figure 1 and Figure 3, is connected to the cam 28 by way of an appropriate driving pin 77. The angular orientation of the driving pins 77, on cam 28 on the left and spring crank 34 on the right, are angularly aligned equally with respect to the shaft 26. This can be done because of the shaft keys 26b and 26b' for the cam 28 and the spring crank 34 respectively. Because of this, when the shaft 26 rotates to provide a compression of the closing springs 64 and 66, the connecting rods 60 on both sides will uniformly draw the yoke 62 towards the spring support plate 68 maintaining both the yoke 62 and the support plate 68 in a generally parallel disposition. There is also provided for operating mechanism 10 a main link 78 which is pivotally hinged to the operating lever 1 6b by the pin 80, and which is pivotally linked with a cam shaft rider 82 by a pin 84.

By referring to Figures 3 and 5, it can be seen that a banana link 86 is interconnected at one end thereof with the pin 84 and consequently the cam rider 82. The other end of the banana link 86 is interconnected with a triangular shaped trip latch 88 by way of a pin 90. A trip latch spring 92 is connected at one end thereof to the trip latch 88 and at the other end thereof to an appropriate anchoring point on the left-most support member 12. The latter spring 92 attempts to provide sufficient spring force to maintain the trip latch 88 hard against a stop 94 on the left-most support member 12. Likewise, an opening release shaft 96 which is similar to and operates in a similar manner to the closing release shaft 56 described previously, is disposed between the support members 12 and protrudes from the left-most support member 12. The opening release shaft 96 when disposed in the angular position shown in Figures 3 and 7 for example, prevents the trip latch 88 from pivoting upon the shaft 98 in a clockwise direction as shown in Figure 3 to thus allow the pin 90 to move significantly to the left as viewed in Figures 3 and 7.

The complete operation of the trip latch 88 and its interaction with the shaft rider 82 and operating lever 1 6b will be described in more detail hereinafter with respect to other figures.

Referring now to Figures 3, 6, and 8, it can be seen that the angular disposition of the opening release shaft 96 is controlled by a shaft mounted lever 96a which in turn is controlled by a second lever 100 which when caused to move in a counterclockwise rotational direction about pivot 100a as shown in Figure 6, will in turn cause the shaft mounted lever 96a to move in a clockwise direction thus rotating the shaft 96 in a clockwise direction. Sufficient rotational movement of the shaft 96 in the clockwise direction will free the left-most corner of the trip latch 88 thus allowing the pin 90 and banana link 86 to move to the left for purposes which will be described hereinafter with respect to other figures. Counterclockwise movement of the lever 100 is caused by right-to-left movement of the shaft 103a (as viewed in Figure 6) of the trip solenoid and manual pushbutton 102.

Referring now to Figure 4, the disposition of the operating mechanism 10 within a circuit breaker apparatus 104 is shown.

The disposition of the operating mechanism 10 relative to the remainder of the circuit breaker apparatus 104 may easily be determined by reference to previously described operating mechanism components. For example, the cam 28 is shown on the left and the ratchet wheel 32 is shown on the right.

The spring charging motor 40 with its shaft 42 (partially broken away) is also shown.

The disposition of the shaft 26 relative to the connecting rods 60, the cam 28 and ratchet wheel 32 is also shown. The outline of the large closing spring 64 is shown as well as the threaded end of the guide rod 72 with its complementary nut 75. The jack shaft 14 is shown extending from left to right in Figure 4. The support structure or casing 106 of the circuit breaker apparatus 104 is shown broken away in Figure 4. It will be noted that the outer bearing surfaces 20 of the jack shaft 14 are shown supported by bearings 108 disposed in the support cabinet or frame 106 of the circuit breaker apparatus 104. Likewise, the jack shaft half bearing 24 supported by and disposed in the left-most member 12 is also shown. The flanges 12c are shown in a supporting disposition with respect to the frame 106, the front part of which is not shown for convenience of illustration. There are also shown fixedly attached to the frame 106, limit of travel or stop pins 109 for the jack shaft rotation limiters 18 (reference to Figure 6 will show the aforementioned elements in an elevational view). Electrically insulating connecting levers or rods 110a, 110b, and 110c are shown pivotally connected to the operating levers 16a, 16b, and 16c, respectively, with appropriate pins 112. Also shown are opening springs 114, which are connected to the operating levers 1 6a and 1 6b by links 116 and pins 118.

By referring again to Figures 1 and 3 in addition to Figure 4, it can be seen that the pins 118 reside in holes or openings 119 in the operating levers 1 6a and 16c, for example.

The opposite ends of the opening springs 114 are connected to brackets 120 which are generally rigidly attached to the frame 106 of the circuit breaker apparatus 104.

Referring once again to Figure 4, it can be seen that the electrically insulating contact connecting rods 110a, 110b, and 110e are physically attached to schematically shown circuit breaker contacts 122a, 122b, and 1 22c, respectively. The previously described contacts 1 22a through 122e may represent the three phase contacts of a three phase electrical system.

Referring again to Figures 1, 3, and 4, it can be seen that when it is desired to open contacts 1 22a through 1 22c, that an appropriate action may be taken such as actuating the trip solenoid or main pushbutton 102 to begin a sequence of events (to be described hereinafter with respect to other figures) which will eventually allow the jack shaft 14 to rotate under the force of the springs 114 to open the main contacts 122a through 122c.

Similarly, a contact closing operation may be begun by actuating the closing solenoid or manual pushbutton 58 to begin a sequence of events (which will be described hereinafter with respect to other figures) which allows the closing springs 64 and 66 to rotate the jack shaft 14 against the force of the opening springs 114 to close the contacts 122a through 122e of the circuit breaker apparatus 104.

OPERATION OF THE CIRCUIT BREAKER APPARATUS Position 1: Closing Spring Discharged, Opening Spring Discharged, Contacts Opened Referring now to Figures 5 and 6 and previously described Figures 1, 3, and 4, a first operating position for the circuit breaker apparatus 104 will be described. In the first operating position, the contact closing springs 64 and 66 are discharged. The contact opening springs 114 are also discharged and the contacts 122a through 122e are opened. By referring specifically to Figure 5, it can be seen that the cam 28 is in a position in which recess 28a therein generally faces downward.

The opening release shaft 96 has been actuated to allow the trip latch 88 to be rotated about its pivot 98 in the clockwise direction. This action allows the cam roller 82 to move to the left as shown in Figure 5. This forces the main link 78 and the operating lever 16b to pivotally collapse around the pin 80 thus causing the insulating rod 110b to move generally downward because of the interconnection therewith at pin 112 thus opening the contacts 122b. Concurrently the jack shaft 14 is rotated counterclockwise in the bearing 24. At this position, the trip latch spring 92 is charged to the extent that it has a tendency to attempt to rotate the trip latch 88 counterclockwise to a position against the stop 94 should the position of the banana link 86 change. In the disposition shown in Figure 5, the crank pin 77 has been moved by the action of the discharging springs 64 and 66 operating against the yoke 62 with the connecting rod 60 to move the pin 77 to its furthest rotational position to the left as viewed in Figure 5. This consequently sets the angular disposition of the cam shaft 26 which is keyed to the cam 28. The relative disposition of the flanges 12a, 12b, and 12c with respect to the frame 106 and the leftmost support member 12 (as shown in Figure 2 for example) is also depicted in Figure 5.

Referring now to Figure 6, the disposition of the closing latch 30, the closing spring crank 34, the ratchet 32, and the interlinkage between the trip solenoid and manual pushbutton 102, and the opening release shaft 96 (as was described previously) is shown. The discharged opening spring 114 is shown disposed between the brackets 120 and the pin 118 of the link 116. As is to be expected, the arrangement of the contacts 122c, the insulating connecting rod 110c, the operating lever l6c, the pin 118, and the jack shaft 14 is the same as that shown with respect to Figure 5 (for another pole). Further rotational travel of the jack shaft 14 in the counterclockwise direction is limited by the abutment of the jack shaft rotation limiter 18 against the stop pin 109. The disposition of the closing release shaft 56 is shown in its normal angular displacement. The ratchet driving pin 39 is shown abutted against the driving surfaces 30a and 34a of the closing latch 30 and the closing spring crank 34 respectively. This means that rotational movement of the ratchet 32 in the direction of the arrow shown in Figure 6 will force the closing latch 30 and the closing spring crank 34 to rotate similarly. The disposition of the spring crank pin 77 on the spring crank 34 is shown to be similar to the disposition of the pin 77 shown in Figure 5, thus allowing the right connecting rod 60 to allow the yoke 62 to move as far to the left as possible with the arrangement shown in Figure 6 thus discharging the springs 64 and 66. As was described previously with respect to Figure 5, the disposition of the flanges 12a, 12b, and 12c on the support frame member 106 is shown.

In order to charge the closing springs 64 and 66 for a subsequent contact closing operation, it is necessary to rotate the charging motor shaft 42 to rotate the eccentric 44 to thus cause the driving pawl 46 to move the teeth of the ratchet 32. This causes the pin 39 for forcing the closing latch 30 and the closing spring crank 34 to move in the direction of the arrow. Naturally it can be seen that if the closing spring crank 34 is moved in the direction of the arrow, the pin 77 must follow therealong consequently drawing the connecting rod 60 to the right and upward. Since both the closing latch 30 and the closing spring crank 34 are keyed to the shaft 26, the shaft 26 will therefore be rotated clockwise.

Referring once again to Figure 5, it can be seen that rotation of the cam shaft 26 in the clockwise direction will cause the cam 28 to rotate in a clockwise direction thus causing the pin 77 to move to the right and upward similarly to the movement of the pin 77 shown and described with respect to Figure 6.

The corresponding, simultaneous movement of both pins 77 on the left-most and rightmost connecting rods 60 will pull the yoke 62 evenly along the guide rods 70, thus compressing the springs 64 and 66 between the yoke 62 and the spring support plate 68.

The shaft rotation depicted in Figures 5 and 6 will continue until the face 30b on the closing latch 30 abuts against the closing release shaft 56.

Position 2: Closing Spring Charged, Opening Spring Discharged, Contacts Opened Referring now to Figures 7 and 8, the disposition of the operating mechanism 10 when the closing springs 64 and 66 have been charged, but where the contacts 122a, 122b, and 1 22c remained opened and the opening spring 114 remains discharged is shown. By referring specifically to Figure 8, it can be seen that the ratchet 32 has been moved in the direction of the arrow by the rotation of the motor shaft 42 to push the closing latch 30 and the closing spring crank 34 by way of the pin 39 operating against the surfaces 30a and 34a, respectively, until an angular disposition is reached where the surface 30b of the closing latch 30 abuts against the closing release shaft 56. It will be noted that in this position, the cranking pin 77 on the spring crank 34 is almost at its extreme right position thus causing the right-most connect ing rod 60 to cause the yoke 62 to compress the closing springs 64 and 66. It will be noted that the crank pin 77 is not at top dead center, or said in another way is not at its furthest right-most position. In fact, the pin 77 has been rotated in the clockwise direction (as viewed in Figure 8) by the ratchet 32 acting upon the spring crank 34 to place the pin 77 in an angular disposition which is slightly past top dead center. This allows the springs 64 and 66 to discharge slightly against the yoke 62 thus pulling against the connecting rod 60 thus biasing the crank 34 to continue to rotate in a clockwise direction when the closing release shaft 56 is operated in such a way as to allow the closing latch 30 to rotate beyond it. If the pin 77 were at top dead center, then the likelihood for undesirable counterclockwise rotation of the spring crank 34 would be as great as the likelihood of desirable clockwise rotation. Since the spring crank 34 is keyed to the shaft 26, it is necessary for the spring crank 34 to rotate in the clockwise direction because it is necessary for the shaft 26 to rotate only in the clockwise direction (as viewed in Figure 8). It will be noted with respect to Figure 8 that even though the closing springs 64 and 66 have been charged, the relative disposition of the contacts 122c, the insulation connecting rod 110c, the operating lever 16c, the spring 114, and the jack shaft 14 remain unchanged with respect to Figures 5 and 6.

Referring now to Figure 7, the corresponding disposition of the cam 28 is shown.

In this case, the cam thus causing the spring crank 34 to rotate clockwise until the springs 64 and 66 have been discharged. Since the spring crank 34 is keyed to the shaft 26, the shaft 26 must also turn counterclockwise.

Referring once again to Figure 7, it can be seen that rotation of the cam shaft 26 in the clockwise direction would cause two things to happen. The first is that the discharging springs 64 and 66 will cause the connecting rod 60 to add to the torque applied to rotate the shaft 26 by moving the cranking pin 77 in a clockwise direction from right to left. In addition, the face of the cam 28 will cause the shaft rider 82 to move upwardly as the cam 28 rotates. It will be noted that the pin 84 which is connected to the banana link 86 which in turn is fixed at the pin 90, (because of the locked disposition of the trip latch) will only allow the pin 84 to move radially with respect to the pin 90. This causes the main link 78 to rotate the operating lever 1 6b clockwise thus elevating the insulating connecting rod 110b to thus interconnect the contacts 122b. Since the common jack shaft 14 rotates all three of the operating levers 16a, 16b, and 16e, all contacts 122a, 122b, and 122c are closed generally simultaneously. If during this latter contact closing operation a fault were somehow sensed on the lines interconnected with the contacts 1 22a through 122c, an appropriate signal would be provided to the trip solenoid 102 to quickly pivot the opening release shaft 96 clockwise thus allowing the relatively stationary pivot point 90 of the trip latch to move rapidly to the left as viewed in Figure 7 to prevent the cam rider 82 from forcing the main link 78 upwardly even though the cam rider 82 itself begins to rise because of the changing contour of the cam 28. In this case it can be seen that the main link 78 would prefer to pivot in a clockwise direction about the pin 80 because of the newly provided freedom of the banana link 86. This of course will prevent force from being supplied to the pin 80 for moving the operating lever 1 6b and consequently the electrically insulating rod 110b. Thus, the contacts 122b will remain open. This is known as the trip free mode of operation. Presuming however, that no trip free operation occurs the final disposition of the various linkages, etc. after a contact closing operation has been completed is as shown in Figures 9 and 10.

Position 3: Opening Spring Discharged, Closed Spring Charged, Contacts Closed Referring now to Figures 9 and 10, a third operating position for the circuit breaker operating mechanism 10 is shown. In this case the closing springs 64 and 66 are discharged as they were in the first operating position shown in Figures 5 and 6. Consequently, the angular disposition of the shaft 26 is the same as the angular disposition shown in Figures 5 and 6. This means that the keyed cam 28, the keyed closing latch 30, and the keyed closing spring crank 34 all have the same disposition as that shown in Figures 5 and 6. It will be noted however that the difference between the first operating position as shown in Figures 5 and 6, and the third operating position as shown in Figures 9 and 10, lies in the angular disposition of the jack shaft 14 and the apparatus which is connected thereto. To be more specific by referring to Figure 10 and comparing Figure 10 with Figure 5 it can be shown that the angular disposition of the jack shaft for the third position (that shown in Figure 10) is such that the operating lever 1 6c has been rotated further clockwise from the disposition of that shown in Figure 6, thus causing the electrically insulating connecting rod 1 lox to move upward to close the contacts 122c.

Likewise, since the jack shaft rotation limiter 18 is fixedly attached to the jack shaft 14, its angular position is now displaced away from the stop 109. Since the link 116 is affixed to the operating lever 1 6c by way of the pin 80, it can be seen that the opening spring 114 has been charged by raising the upper end of the spring 114 relative to the bracket 120.

Referring now to Figure 9, the disposition of the cam 28 is shown. It will be noted as was mentioned previously that it occupies the same angular disposition as it occupied in the first disposition shown in Figure 5. In this case however, as was described with respect to Figures 7 and 8, the trip latch 88 has been pivoted about its axis 98 by the discharging action of the spring 92 to place the trip latch 88 against the stop 94 thus allowing the opening release shaft 96 to assume its normal relaxed position. This tends to hold the trip latch 88 in the position shown in Figure 9.

Such being the case, the pivot 90 for the banana link 86 is fixed, and the disposition of the cam follower 82 on the surface of the cam 28 is forced by the banana link 86 through the common pin 84 to hold the main link 78 in an upright position relative to its disposition shown in Figure 5. This in turn holds the main operating lever 1 6b in an upward position. This causes the common pin 112 to hold the insulating connecting link 110b in such a disposition as to close the contacts 122b. Of course, as was mentioned previously, all of the contacts are controlled by the common jack shaft 14. Consequently, it can be said that all of the contacts 122a through 122c are closed at this time.

Referring once again to Figure 10, the arrangements of the closing solenoid and manual pushbutton 58 is shown. The latter solenoid has an extended plunger 58a which when actuated to move to the left causes the tab or lever 56a on the closing release shaft 56 to rotate clockwise. This changes the angular disposition of the milled away portion of the closing release shaft 56 for clearing the surface 30b of the closing latch (shown in Figure 8). This allows the springs 64 and 66 to discharge to rotate the shaft 26 to the position shown in Figures 10 and 6 for example.

By referring to Figures 8 and 10, it is to be noted that in a circuit breaker closing operation the disposition of the closing latch 30 and the closing spring crank 34 relative to the pin 39 on the ratchet 32 allows the springs 64 and 66 to discharge from the position shown in Figure 8 to the position shown in Figure 10. This causes the contacts 122c to move from the opened position shown in Figure 8 to the closed position shown in Figure 10 without requiring rotational movement of the ratchet wheel 32.

Position 4: Closing Spring Charged, Contacts Closed, Opening Spring Charged By referring to Figures 7, 8, 9, and 10, it can be seen that a fourth position for the apparatus and linkages of the operating mechanism 10 is possible. In this case immediately after a circuit breaker has been successfully closed, that is immediately after the circuit breaker contacts 1 22c have been closed, it is desirous to once again quickly charge the closing springs 64 and 66. Consequently, upon the opening of the circuit breaker contacts 122c those contacts may be quickly reclosed again. It is well known that a desired operating sequence for a circuit breaker is as follows: opening of the main contacts, reclosing of the main contacts, opening of the main contacts once again if necessary. By examining Figures 7 through 10, it can be seen that in the desired fourth position the closing springs 64 and 66 are in the disposition shown in Figures 7 and 8 and the main contacts 1 22c are in the disposition shown in Figures 9 and 10. In order to accomplish this, the motor 42 shown in Figures 1 and 3 for example, is allowed to rotate the shaft 42 to charge the springs 64 and 66 as was described previously without affecting the disposition of the contacts 122c.

By examining Figures 7 and 9, it can be seen that the shaft 26 may be rotated clockwise through a sufficient angular displacement to move the closing spring crank pin 77 from the extreme left as shown in Figure 9 to the spring charged position shown in Figure 7. This may occur without the cam follower 82 changing its radial disposition relative to the shaft 26. In the spring charged position such as shown in Figure 7, with the trip latch in the latched position such as shown in Figures 7 and 9, the cam follower 82 will not fall into the depression 28a as shown in Figure 7.

Rather it will remain on the outer large radius of the cam 28 until a tripping operation has been begun by angularly rotating the opening release shaft 96 to allow the trip latch 88 to assume the position shown in Figure 5 for example. It will be noted with regard to the latter operation that the trip latch 88 will not reset itself, i.e. assume the position shown in Figure 7 with the left side of the trip latch 88 abutting against the point 96b on the opening release shaft 96 until the roller 82 has been allowed to enter the depressions 28a such as is shown in Figure 7. If the preceding sequence of events has occurred, then the circuit breaker apparatus is in condition for a quick reclosure after a prior opening merely by discharging the closing springs 64 and 66 in the manner described previously. In the event that the tripping operation took place on the discharged closing springs 64 and 66, consequent reclosure of the contacts 1 22b cannot occur until the motor or similar means 40 has rotated the shaft 42 to such a position that the springs 64 and 66 have been charged and the roller 82 has fallen to the recess 28a.

Referring now to Figures 11 and 12, still another embodiment of the invention, a vacuum circuit interrupter 300 is shown. In this case there are provided two elongated, generally parallel, spaced apart unitary support members 212a and 212b. It will be noted that the latter two members support an operating mechanism, such as is shown to the right in Figure 11, and the contact driving linkages and contact apparatus, such as is shown to the left in Figure 11. In this embodiment of the invention, a shaft 226 traverses the space between the parallel plates 212a and 212b. Keyed to one side of the shaft 226 is a cam 228. A cam rider 282 is provided which is pivotally pinned to a banana link 284 and a main link 278. The main link is pivot tally hinged to a cranking lever 301 which in turn is keyed or otherwise securely fastened to a rotatable jack shaft or crank shaft 302.

Also securely attached to the jack shaft 302 is a bell crank 304, one end of which is pinned at 311 to a connecting rod 310 for an opening spring 214. The other end of the bell crank 304 is connected by way of a pin 307 to a driving rod 306. The previously described banana link 284 is connected to a trip latch 295 which is pivotable about a trip latch pivot 298. A spring 292 is provided to maintain the trip latch 295 against a stop 294.

Likewise, an opening release shaft 296 of the type described with respect to Figures 1, 3, and 4 for example, is provided for allowing the trip latch 295 to rotate counterclockwise about the pivot 298 in appropriate circumstances for causing a trip motion to be applied to the rod 306. Spring crank pins 277 are disposed upon the cam 228 to actuate connecting rods 260 to compress an opening spring 264 between a spring support plate 268 and a yoke 262. As was the case with respect to other embodiments of the invention, a guide rod 272 is provided for the spring 264.

A nut 273 is threaded on the upper end of the guide rod 272 and a similar nut 275 is threaded on the lower end thereof for securing the rod 272. There are provided three tandemly mounted vacuum bottle circuit interrupters 322a, 322b, and 322c. Insulating connecting rods 350a, 350b, and 350c are connected to the contacts (not shown) of the vacuum bottle circuit interrupters 322a through 322c, respectively. The bottoms of the insulating connectings rods 350a through 350c are connected to hinged ends 334b for example, on bell cranks 330a, 330b, and 330c respectively. The previously mentioned bell cranks are pivotal about pivot pins 332b and 332c for example for bell cranks 330b and 330c, respectively. A similar hinging arrangement exists for bell crank 330a. The pin 332c, for example, is supported in openings 333 in the previously described elongated support members 212a and 212b. The pins 332a and 332d may be likewise supported. Consequently it can be seen that the tolerance between the centers of the holes 333 for the bell cranks 330a, 330b, and 330c and the holes for the shaft or pivots 298 and 226 for example of the operating mechanism are maintained within relatively closed tolerances because of the common support members 212a and 212b.

This is due to the fact that all the holes or openings are placed in unitary supports. The connecting rod 306 has nut members 340b and 342b disposed thereon for pole piece 322b.

A nut member 340c is also shown for pole piece 322c. For purposes of simplicity of illustration, only the operating mechanism with respect to pole 322b will be further described, it being understood that the operating mechanism for poles 322a and 322c operate synchronously therewith and in a similar manner thereto. Disposed between the adjustable nut members 340b and 342b is a spring 344b which is maintained in place by spring support members 343b on the left and 345b on the right, as viewed in Figure 11. Spring 344b encircles rod 306. There is provided a linkage block 338b upon which is disposed a hinge pin 336b on which a portion of the bell crank 330b rotates for opening and closing the contacts of the vacuum bottle interrupter 322b. The region between the block 338b and the nut 340b may expand to form a gap during certain operating conditions of the circuit breaker apparatus 300.

To close the contacts of the pole pieces 322a through 322c the electrically insulating rods 350a through 350e are raised by moving the connecting rod 306 towards the right as viewed in Figure 11 to pivot in tandem and synchronously the bell cranks 330a through 330c upwards. The connecting rod 306 is moved to the right by pivoting the shaft 302 counterclockwise. This occurs when the spring 264 is released to drive the cam 228 counterclockwise thus causing the cam rider 282 to force the cranking lever 301 in the counterclockwise direction. This also causes the pin 311 to drop, pulling the connecting rod 310 down thus compressing the opening spring 214.

To open the contacts 322a through 322c, the rod 306 must move to the left. This occurs when the opening trip release shaft 296 is rotated counterclockwise allowing the trip latch 295 to move upward in a counterclock- wise direction thus freeing the banana link 284. This allows the spring 214 to discharge pulling the connecting rod 310 up thus rotating the bell crank 304 to the right in a clockwise direction.

During the contact closing operation, the nut 342b for example, is moved to the right by the connecting rod 306, transmitting the rightward directed motion through the spring 344b without significantly compressing the spring. This moves the block 338b to the right which in turn rotates the bell crank 330b counterclockwise, thus elevating the insulating connecting rod 350b to close the contacts of the vacuum circuit interrupter 322b, for example. After the contacts in the vacuum circuit breaker 322b have made contact with each other, further travel of the connecting rod 306 to the right tends to compress the spring 344b and to open or enlarge the gap in the region 346b between the block 338b and the nut 340b.

During the contact tripping or opening operation, when the rod 306 moves to the left, the force of acceleration of the discharging opening spring 214 will rapidly cause the gap 346b to close. This is assisted by the action of the expanding spring 344b which also tends to accelerate the nut 340b. At the instant the nut 340b impacts the block 338b from the right a large force of acceleration is transferred to that block which in turn tends to move the electrically insulating rod 350b downward with great force thus tending to break any welds which may have formed between the contacts of the vacuum interrupters 322a through 322c during the closing operation. The force of acceleration provided by the spring 344b and the opening spring 214 tends to jar or shake the entire mechanism 300. The force is required as the previously described contact welds are often a serious problem with vacuum bottle interrupter contacts. If the support members for the operating mechanism of Figure 11 were physically separated from the support members for the vacuum bottle interrupters, the repeated forces of acceleration during the contact opening operation would eventually tend to misalign the various critical alignment elements, i.e. the alignment between pin 332c and shaft 226 for example. However, because of the unitary nature of the support members 212a and 212b, it is very difficult to misalign the critical component parts for the apparatus of the vacuum circuit interrupter 300.

It is to be understood with respect to the embodiments of this invention that the concept of the outboard operating mechanism components is not limited to the particular type of stored energy mechanism shown in Figures 1 through 10. Furthermore, it is to be understood that the spacing between the support members 12 in the embodiment of Figures 1 through 10 and the support members 212a and 212b in the embodiment of Figures 11 and 12 is not limiting. It is also to be understood that the concepts associated with the embodiments shown in Figures 1 through 10 is not limited to any particular kind of circuit breaker. The circuit breakers may be vacuum breakers, magnetic circuit breakers, gas circuit breakers, or others. In a like manner, even though the embodiment described with respect to Figures 11 and 12 deals primarily with vacuum type circuit interrupters, the concepts taught with respect to the latter embodiment are not limited to vacuum type circuit interrupters.

An advantage lies in the fact that a circuit breaker operating mechanism may be provided with supports which are inboard of all the critical operating components such as the cam, the ratchet, and the closing spring connecting rods. Another advantage lies in the fact that such an arrangement allows for a simply made and installed cam shaft. Still another advantage lies in the fact that one of the support members for the operating mechanism may be utilized to bear the force of the center pole of a three phase circuit breaker, thus tending to reduce jack shaft deflection. Another advantage lies in the fact that a specially milled or machined closing release shaft may be utilized in conjunction with a closing latch for efficient and effective closing of the circuit breaker contacts.

Another advantage lies in the fact that one of the connecting rods for the closing spring may be connected directly to a pin on the cam.

Still another advantage lies in the fact that in one embodiment of the invention, unitary support members are provided for maintaining close alignment tolerances between portions of the circuit breaker operating mechanism and portions of the circuit breaker contact opening and closing linkages.

WHAT WE CLAIM IS: 1. A circuit interrupter comprising a pair of separable main contacts, a movable one of which is carried by a connecting rod which is connected with an operating mechanism by a linkage, actuation of the linkage serving to open and close said separable main contacts, the operating mechanism for actuating the linkage being mounted on a pair of spaced apart support members, a shaft of the said linkage extending between the spaced apart members, the operating mechanism having a cam shaft extending between the spaced apart members, the cam shaft carrying a cam engaged by lever means forming part of said linkage, the cam being provided with a crank pin actuating a member which effects stressing of a charging spring.

2. A circuit interrupter as claimed in claim 1, wherein said contacts are disposed within a vacuum bottle.

3. A circuit interrupter as claimed in claim 1 or 2, wherein said support members comprise two punched members.

4. Circuit interrupters, constructed and adapted for use substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. of the vacuum circuit interrupter 300. It is to be understood with respect to the embodiments of this invention that the concept of the outboard operating mechanism components is not limited to the particular type of stored energy mechanism shown in Figures 1 through 10. Furthermore, it is to be understood that the spacing between the support members 12 in the embodiment of Figures 1 through 10 and the support members 212a and 212b in the embodiment of Figures 11 and 12 is not limiting. It is also to be understood that the concepts associated with the embodiments shown in Figures 1 through 10 is not limited to any particular kind of circuit breaker. The circuit breakers may be vacuum breakers, magnetic circuit breakers, gas circuit breakers, or others. In a like manner, even though the embodiment described with respect to Figures 11 and 12 deals primarily with vacuum type circuit interrupters, the concepts taught with respect to the latter embodiment are not limited to vacuum type circuit interrupters. An advantage lies in the fact that a circuit breaker operating mechanism may be provided with supports which are inboard of all the critical operating components such as the cam, the ratchet, and the closing spring connecting rods. Another advantage lies in the fact that such an arrangement allows for a simply made and installed cam shaft. Still another advantage lies in the fact that one of the support members for the operating mechanism may be utilized to bear the force of the center pole of a three phase circuit breaker, thus tending to reduce jack shaft deflection. Another advantage lies in the fact that a specially milled or machined closing release shaft may be utilized in conjunction with a closing latch for efficient and effective closing of the circuit breaker contacts. Another advantage lies in the fact that one of the connecting rods for the closing spring may be connected directly to a pin on the cam. Still another advantage lies in the fact that in one embodiment of the invention, unitary support members are provided for maintaining close alignment tolerances between portions of the circuit breaker operating mechanism and portions of the circuit breaker contact opening and closing linkages. WHAT WE CLAIM IS:

1. A circuit interrupter comprising a pair of separable main contacts, a movable one of which is carried by a connecting rod which is connected with an operating mechanism by a linkage, actuation of the linkage serving to open and close said separable main contacts, the operating mechanism for actuating the linkage being mounted on a pair of spaced apart support members, a shaft of the said linkage extending between the spaced apart members, the operating mechanism having a cam shaft extending between the spaced apart members, the cam shaft carrying a cam engaged by lever means forming part of said linkage, the cam being provided with a crank pin actuating a member which effects stressing of a charging spring.

2. A circuit interrupter as claimed in claim 1, wherein said contacts are disposed within a vacuum bottle.

3. A circuit interrupter as claimed in claim 1 or 2, wherein said support members comprise two punched members.

4. Circuit interrupters, constructed and adapted for use substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.