Switch Operating Device With Spiral Spring Charging Means And Cam Release Means

Abstract

An operating device is provided for actuating an electrical switch between an opened and closed condition. The operating device includes a stored energy means such as the spring which is releasable to rotate a shaft that is mechanically connected to open or close the switch. Recharging of the spring is effected by means of a gear motor which is also operable to hold the spring from reverse operation. Automatic means are provided for effecting the operation of the stored energy means.

Description

BACKGROUND OF THE INVENTION

Distribution systems designed for manual operation of reciprocating controlled air disconnect switches is impractical in the load managment principle due to the time and expense necessary for completing just one operation. A basic link in establishing an automated system under the load management principle is establishing an automated system to fulfill the switching requirements on these distribution systems. With the capability of remote operation, faulted sections can be isolated faster, restoring service to the unaffected areas which will increase the system reliability.

On normal distribution systems, loading is limited by service continuity considerations such that there is considerable excess capacity in the system to allow for extended periods of overloads due to faulted lines. A quick isolation of these lines will reduce the overload time, on the faulted line, allowing a higher initial capacity on the line.

The ability to increase loading on the existing feeders by using an automated system can result in significant savings on future line constructions.

With the present invention, the automated system can be a simple single direction command system or it can be a complex read-out/read-in system. In either case, the basic control would be to operate the switches in an area to isolate the fault based on observed conditions. Control could be made more complex by adding relays and using equipment of the substation to locate the fault and including a feature of the present invention of three successful operations of the switch operating device or unit to complete an open-close-open sequence for the operation.

SUMMARY OF THE INVENTION

The switch opeating device herein set forth is provided with a solenoid release spring trip mechanism which supplies an output for actuation of switches such as a disconnect switch. The operating device includes means for motor recharging of the spring. Once the spring is charged, the operating device has sufficient capacity for three successive operations without recharging. This feature permits operation when the motor energizing source is dead and makes possible the breaker system for false isolation. Upon completion of an operation, the motor will automatically operate to recharge the spring to its potential three operation condition. The output of the operating device is a reciprocating motion supplied by a 180.degree. rotation of the output shaft which puts the control and toggle in both open and closed position. The trip signal necessary for actuation of the operating device can be supplied from a number of systems which are compatible with the existing utility practices.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of the operating device of the invention connected to supply reciprocal motion to a remotely located switch device, indicated as being disposed at the top of a pole;

FIG. 2 is an enlarged view of the operating device with the enclosure cover removed to show the internal mechanism partly in left side elevation and partly in section;

FIG. 3 is an enlarged view partly in front elevation and partly in vertical section of the operating device shown in FIG. 2;

FIG. 4 is an enlarged fragmentary view of the spring drive arrangement taken in a plane represented by the line IV--IV in FIG. 2;

FIG. 5 is an enlarged fragmentary view in side elevation of the cam means for locking the spring driven shaft against rotation and taken in a plane represented by the line V--V in FIG. 4;

FIG. 6 is an enlarged fragmentary view of the toggle mechanism and solenoid release arrangement for the unlocking of the cam means; and,

FIG. 7 is a fragmentary view in front elevation of the toggle mechanism and solenoid release arrangement shown in FIG. 6.

DESCRIPTION OF THE INVENTION

Referring to the drawings, there is shown in FIGS. 1, 2 and 3 a switch operating device 10. The operating device includes a rectangular frame 11 having a horizontal front bar 12 and left and right side bars 13 and 14 and a closing rear bar 15. Extending rearwardly of the rear bar 15 are a pair of spaced apart mounting brackets 16, one of which is shown, which are securely fastened to the outwardly extending legs of a channel bracket 17 that is bolted or otherwise secured to a supporting pole 18. The operating device 10 includes the stored energy means 21 which is operatively connected to rotate a shaft 22 that is journaled in the side members 13 and 14 of the frame. As shown, the shaft 22 extends outwardly of the side members 13 and 14. The extending ends having secured thereto arm members 23 and 24, respectively. Rotational movement of the shaft 22 affects the physical movement of the arms 23 and 24, the output of which is transmitted as a reciprocable movement to a switch device generally identified by the reference symbol 25. The switch device 25 per se is not a part of the present invention and, thus, is not shown in detail. As herein utilized, the operating device 10 will move an operating lever 26 affixed to the operating shaft 27 of the switch device 25, upwardly and downwardly selectively to a switch closed position or to a switch open position, respectively. To this end, the free ends 23A and 24B of the shaft arms 23 and 24 are pivotally secured as with bolts to the free end of a pair of spaced arms 31 and 32 of a bracket 33. The opposite ends of the arms 31 and 32 of bracket 33 are bent inwardly and are pivotally secured to an upwardly extending rod 36 by means of a bolt 37. At its opposite end, the rod 36 is pivotally connected to the operating lever 26 of the switch device 25. Thus, rotation of the shaft 22 in a counterclockwise direction, as viewed in FIG. 2, will affect counterclockwise rotation of the arms 23 and 24. As the arms 23 and 24 rotate counterclockwise, the arms 31 and 32 of the bracket move with the arms 23 and 24. Since the bracket 33 is pivotally connected both to the arms 23 and 24 and to the rod 36, the bracket will move in an arcuate path of travel and upwardly. As the bracket 33 moves upwardly, it moves the rod 36 upwardly which, in turn, pivots the arm 26 upwardly thereby rotating the shaft 27 in a counterclockwise direction to effect a closing of switch device 25. When the switch device 25 has been closed, the shaft 22 will have been rotated approximately 180.degree. so that the arms 23 and 24 are in an upright position, 180.degree. displaced from the position as depicted in FIGS. 2 and 3. To stop rotation of the shaft 22 when the switch device 25 has been operated to a closed condition, a cam disc 41 having diametrically disposed cam stops A and B is provided. The cam disc 41 is mounted on and secured to rotate with the shaft 22. In the position depicted in FIGS. 2 and 3, the cam disc 41 is shown in a position in which the switch device 25 is in a switch open position. In this position, the cam stop B is in the lowermost position and is engaged against the releasable positive stop means 42 which includes a displaceable roller 43. With the roller 43 in the stop position, as depicted in FIGS. 2 and 3, the cam stop B abuts the roller 43 precluding rotation of the cam disc 41 in a counterclockwise direction. Since the cam disc 41 is secured to the shaft 22, the stop means prevents rotation of the shaft 22. To effect an operation of the switch device 25 to a switch closed condition, the roller 43 is displaced by operative release means 45. The release means 45 effect the withdrawal of the roller 43 from engagement from the abutting surface of the cam stop B allowing the cam disc 41, and thereby the shaft 22, to rotate. As soon as the cam stop B rotates away from the stop location, the roller 43 is urged to return to its stop position but is prevented from doing so by the peripheral surface of the cam disc. Thus, the roller 43 will roll on the peripheral surface C of the cam disc 41 until such time as the disc has been rotated a sufficient distance to locate the stop cam surface A into the lowermost position. At this time, the roller 43 will ride on the flat surface D of the cam disc and is in position wherein the further counterclockwise direction of cam disc 41 will move the radial surface of the cam stop A into abutting engagement with the roller. When this condition obtains further rotation of both the disc 41 and the shaft 22 is precluded and the switch device 25 will have been actuated to a switch closed condition.

The roller release means 45 is supported on a vertical depending plate 46 that is securely fastened to front and rear horizontally disposed angle bar sections 47 and 48. As shown in FIGS. 6 and 7, a stop roller 43 is rotatably mounted on a bolt shaft 51 which extends laterally through parallel spaced apart pivot links 52 and 53. The rearwardly extending ends of the pivot links 52 and 53 are disposed on each side of an abutment block 54 and are pivotally secured thereto by means of a pin 56. A pair of spaced vertically extending guide arms 57 and 58 are at their uppermost ends pivotally engaged on the pin 56 on each side of the links 52 and 53. At their lowermost ends, the guide arms 57 and 58 are pivotally connected by a pin 60 astraddled a bracket 59 which is bolted to the vertical plate 46.

A release arm or lever 61 is pivotally mounted on a bolt 62 which is carried in a hub 63 that is welded to the sides of the vertical plate 46. The upper end of the release lever 61 is pivotally engaged on a pin 64 which also extends through a pair of links 66 and 67. The upper ends of the links 66 and 67 are pivotally engaged on a bolt shaft 51, as shown in FIG. 7.

For automatic operation of the lever arm 61 for releasing the cam disc 41, there is provided a solenoid operator 75. The solenoid is supported on the vertical plate 46 by means of the bracket 76. An operative connection between the solenoid plunger 77 and the lever 61 is established by means of a tongue and pin connection 78 as shown in FIGS. 6 and 7. As shown, a free end of a solenoid plunger 77 is provided with a flat extension 79 which extends through a slot 81 formed in the lever 61. A pin 82 is inserted through the tongue portion 83 of the extension 79 and is adapted to engage in a semicircular recessed portion 84 formed in the lever 61.

In operation, energization of the solenoid 75 will affect axial leftward movement of the associated plunger 77, as viewed in FIGS. 2 and 6. Upon leftward movement of the plunger 77, the tongue and pin connection 78 will effect pivotal movement of the release lever 61 about the bolt 62. As a result, the pivotal joint established between the upper end of the lever 61 and the lower ends of the links 66 and 67 will break rightwardly, as viewed in FIGS. 2 and 6. This rightward breaking of the links 66 and 67 will cause the righthand ends, FIG. 6, of the pivot links 52 and 53 to move downwardly thereby moving the stop roller 43 downwardly. Simultaneously with the downward movement of the pivot links 52 and 53, the guide arms 57 and 58 will pivot about the pin 60. As a result, the stop roller 43 is withdrawn from engagement with the stop cam surface B in an arcuate path of travel. With the withdrawal of the cam stop roller 43, the cam disc 41, and, therefore, the shaft 22 immediately starts to rotate without a shock impact being transmitted to the system. Energization of the solenoid 75 is momentary and only sufficiently long enough to allow the cam disc 41 to rotate sufficiently far enough to move the stop surface B clear of the stop roller 43. With the solenoid 75 deenergized, the release lever 61 and thereby the stop roller 43 is returned to the stop position, depicted in FIGS. 2 and 6. To this end, a positive return means is provided to effect such return and includes a spring 86 which has one end secured to a bracket 87. The bracket 87, in turn, is secured to the end of the release lever 61 at a point above the pin 64. The opposite ends of the spring 86 is secured to a bracket 88 which, in turn, is secured to an angle bracket 89 that is screw fastened to the vertical plate 46. Thus, upon deenergization of the solenoid 75, the spring 86 operates to forcefully return the release lever 61 to its upright position. However, at this time the cam disc 41 is rotating and the roller 43 engages on the peripheral surface C of the cam disc 41. Thus, the spring 86 cannot effect the return of the release lever 61 to its full upright or initial position and the spring 86 thereby forcefully maintains the roller 43 against the surface C of the cam disc 41. When the disc 41 has rotated sufficiently far enough to bring the flat surface D adjacent the roller 43, the roller under the bias of the spring 86 follows and maintains engagement with the surface D. Thus, when the disc 41 has rotated to a position wherein the stop surface A is in a bottom vertical position, the roller 43 will be in the path of travel of the surface A thereby stopping further rotation of the disc 41.

To prevent the spring 86 from over-returning the release lever 61, a positive stop is provided. The positive stop comprises a threaded bolt 91 adjustably carried by the release lever 61, and a stop bar 92 which is welded to the top surface of the bracket 59 and which is adapted to be engaged by the head of the bolt 91.

A shock absorber is also provided to ease the return of the toggle arrangement to its reset position. To this end, a plurality of rubber pads 96 are mounted on the threaded bolt 97 that is carried by the outwardly extending leg portion 98 of the bracket 89. Interposed between the leg portion 98 of bracket 89 and ahead of the bolt 97 is another rubber pad 101. Thus, as the linkage assembly associated with the release lever 61 is forcefully returned to its reset position under the influence of the spring 86, impact shock is absorbed by the rubber pads 96 and 101.

For servicing purposes or for any other reason, the operating device 10 may be manually operated if so desired. Manual operation of the device 45 is accomplished by simply applying hand pressure to the lower ends of the release lever 61 thereby tripping the toggle mechanism.

As previously mentioned, the shaft 22 is rotatably driven to effect the actuation of the switch device 25 to an open or closed condition. To this end, a pair of bearing retainers 111 and 112 are supported in axial alignment in the side members 13 and 14 of the frame. Bearings 114 and 116 disposed in the retainers 111 and 112, respectively, rotatably support the output shaft 22. As previously mentioned, the cam disc 41 is mounted on the end of the output shaft 22 being connected to rotate with the shaft by operation of a key 117. A spring housing 120 is disposed on the opposite ends of the output shaft 22 being supported thereon for rotation relative to the shaft 22 by a pair of bearings 121. Power for driving the shaft 22 to actuate the switch device 25 is obtained from a motor spring 125 disposed within the housing 120. One end 126 of the motor spring 125 is held within an axially extending slot 127 formed in the shaft 22. The opposite end 128 of the motor spring 125 extends through a slot 129 formed in the spring housing 120, and is secured to the exterior thereof by means of threaded fasteners 131. Thus, assuming that the motor spring 125 is charged and with the housing 120 held against rotation and the shaft 22 released, the stored energy in the motor spring 125 will affect the rotation of the shaft 22 in the direction indicated by the directional arrow in FIG. 5.

To recharge the motor spring 125, a power means is provided. As shown in FIGS. 3 and 4, the power means includes a gear motor 135 which is carried on an angle bracket 136 that is welded or otherwise secured to the vertical plate 46. The output shaft of the gear motor 135 is provided with a sprocket gear 137 and an associated sprocket gear 138 is secured to the axial end phase of a hub portion 139 of the spring housing 120. An operative drive between the motor 135 and housing 120 is established by a drive chain 141 which is entrained about the sprockets 137 and 138. Thus, with the release lever 61 reset to its initial position that it occupies as depicted in FIGS. 2 and 6, wherein the stop roller 43 is in blocking position in front of one or the other of the cam surfaces A or B, the shaft 22 will be restrained from rotating in a counterclockwise direction. Energization of the gear motor 135 will affect rotation of the gear motor output shaft 142 in a direction to drive the housing 120 in a counterclockwise direction, as viewed from the left in FIGS. 3 and 4, to thereby recharge the motor spring 125. The source of energizing power for the gear motor 135 is obtained from the lines (not shown) to which the switch device 25 is connected and operates control.

For effecting the energization of the gear motor 135 after the switch device 25 has been actuated to either a switch closed or a switch open condition, there is provided an automatic control 145. The control means 145 includes a traveling nut member 146 which is threadedly engaged on a threaded axially extending hub portion 147 of a motor shutoff flange 148. As shown, the motor shutoff flange 148 is secured to the axial end face of the spring housing hub 139 so as to rotate with the housing. The traveling nut member 146 is provided with a radial driving flange 151. A pin 152 is secured to rotate with the cam disc 41 extends laterally therefrom to any direction parallel to the axis of the shaft 22. The laterally extending ends of the pin 152 extends through an opening 153 formed in the radial nut flange 151. Thus, rotation of the cam disc 41 in a counterclockwise direction as viewed from the left in FIG. 4 will affect rotation of the nut 146 thereby causing it to move axially towards the spring housing 120 and a limit switch 156. The limit switch when actuated operates to effect energization of the gear motor 135 for recharging the motor spring 125. In the preferred arrangement, the limit switch 156 is positioned at a distance from the nut flange 151, when the nut member 146 is in its initial start position, to allow the cam disc 41 to rotate through 540.degree. of rotational travel. In other words, the motor spring 125 is sufficiently strong enough to insure three complete operations of the switch device 25; that is, to a closed condition--to an open condition and then to a closed condition again. Thus, after the motor spring 125 has operated to drive the switch device through three operative conditions, the nut member 146 will have been driven axially toward the housing 120, a distance sufficient to have the flange 151 engage and operate the actuating level of the limit switch 156. With the limit switch 156 actuated, the gear motor 135 will be energized to recharge the motor spring 125. In recharging the motor spring 125, the gear motor 135 operates to rotate the spring housing 120 in a clockwise direction, as viewed from the right in FIG. 4. As a result, the threaded portion 147 of the motor shutoff flange 148 also rotates in a clockwise direction with the housing 120. Since the stop roller 43 is in position to restrain the cam device 41 from rotating, the nut member 146 is also held stationary. Thus, the rotation of the threaded portion 147 in a clockwise direction as viewed from the right in FIG. 4, will effect axial leftward movement of the nut member 146. When the housing 120 has been rotated a sufficient number of turns to fully recharge the motor spring 125, the flange 151 of the nut member 146 will have been moved to its initial position, as depicted in FIG. 4. In this position, the flange 151 will engage the actuating lever of a limit switch 157 thereby deenergizing the gear motor 135.

When the switch device 25 is actuated to a switch open condition, the shock loading imposed on the operating device is relatively heavy and would damage the operating mechanism. To prevent damage to the operating device 10, a shock absorbing means 160 is provided. As shown in FIG. 2, the shock absorbing means 160 includes an enclosed ended cylindrical tube 161 which has its lower end disposed between the spaced apart legs of the channel bracket 16. A bolt or pin 162 extending through the legs of the channel member and the lower end of the tube 161 pivotally anchors the cylinder in operative position. Working in the cylinder 161 is a piston 163 having an axial rod 164 which extends outwardly of the tube 161. A compression spring 166 carried within the tube and confined therein between the lower end of the tube and the piston 163. Thus, the spring 166 is operative to resist and absorb any shock loads there may be imparted to the rod 164. The outwardly extending end of the rod 164 extends through a pivot block 167 which is disposed between and is pivotally connected to a pair of spaced apart arms 168 and 169.

One end of each of the arms 168 and 169 are pivotally connected to associated leg portions of the channel bracket 17. The opposite end of the arms 168 and 169 are pivotally connected to the rod 36 by means of a bolt 37. A stop nut 172 is adjustably engaged on a threaded portion of the rod 164 and operates to limit the extent of axial downward movement permitted to the rod 164. Thus, operation of the operating device 10 to actuate the switch device 25 to a switch open condition will not impose a shock load to the mechanism, but the shock absorbing device 160 will absorb most of the shock load attending the opening of the switch device.

It will be apparent from the foregoing description that an automatic rechargeable stored energy switch operator has been provided which is capable of being actuated remotely and have the capability of at least three distinct operations without requiring recharging. The operator incorporates its own recharging arrangement which is energizable from the power source with which it is associated. Thus, with the operating device having the unique capabilities of at least three operations without recharging, it is operational independently of its recharging source and thus, makes possible the breaker search system for fault isolation.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In an operating device for operating a disconnect switch having at least one pair of separable contacts and a handle structure movable to open and close said contacts;

a frame;

an output shaft rotatably supported by said frame;

an actuating rod operably connected to said output shaft and to said disconnect switch handle structure for effecting the movement of said contacts;

a cam disc secured to said output shaft to rotate with it, said cam disc having two diametrically disposed stop surfaces;

a releasable stop lever pivotally supported by said frame and having a roller which rolls on the peripheral surface of said cam disc into abutting engagement with one or the other of said stop surfaces to thereby restrain said output shaft against rotation;

drive means including a housing mounted on said output shaft for rotation relative to said shaft;

a spiral spring coiled within said housing and having one end connected to said output shaft and its opposite end connected to said housing, said spiral spring being operable to constantly urge said output shaft in a direction to operate said handle structure;

a gear motor operably connected to effect the rotation of said housing relative to said output shaft for recharging said spiral spring; and,

a signal responsive solenoid operably carried by said frame in position to move said stop lever to disengage said roller from said cam disc stop surface, thereby releasing said output shaft for rotation under the influence of said spiral spring for operating the handle structure of said disconnect switch.

2. An operating device according to claim 1 wherein there is provided a first control switch operable when actuated to effect the operation of said gear motor to recharge said spiral spring,

and a means for actuating said control switch including a screw and nut arrangement operatively connected for rotation relative to each other, wherein the rotation of said output shaft effects relative rotation between said screw and nut to move the nut into actuating engagement with said control switch,

and rotation of said housing under the influence of said gear motor for recharging said spiral spring will effect relative rotation of said screw and nut to return said nut to its initial position; and,

there is provided a second control switch operable when actuated to interrupt the operation of said gear motor, said second control switch being disposed in a position wherein it is actuated by said nut when said nut is returned to its initial position.

3. In an operating device for operating a disconnect switch having at least one pair of separable contacts movable to open and close positions;

a frame;

an output shaft rotatably supported by said frame and operably connected to effect the movement of said contacts;

a cam disc secured to said output shaft to rotate with it, said cam disc having two diametrically disposed stop surfaces;

a releasable stop lever pivotally supported by said frame and having a roller which rolls on the peripheral surface of said cam disc into abutting engagement with one or the other of said stop surfaces to thereby restrain said output shaft against rotation;

a housing mounted on said output shaft for rotation relative to said shaft;

a spiral spring coiled within said housing and having one end connected to said output shaft and its opposite end connected to said housing, said spiral spring being operable to constantly urge said output shaft in a direction to operate said contacts;

a gear motor operably connected to effect the rotation of said housing relative to said output shaft when energized for recharging said spiral spring, said gear motor being also operable when deenergized to restrain said housing from rotating; and,

a signal responsive solenoid operably carried by said frame in position to move said stop lever to disengage said roller from said cam disc stop surface, thereby releasing said output shaft for rotation under the influence of said spiral spring for operating the contacts of said disconnect switch.

4. In an operating device;

a frame;

an output shaft supported by said frame for rotation between a first and second position which is 180 degrees apart;

a housing mounted on said shaft for rotation relative to said shaft;

a spiral spring coiled about said shaft and disposed within said housing, said spiral spring having one end secured to said housing and its other end secured to said shaft;

a gear motor carried by said frame and operably connected to rotate said housing in one direction relative to said shaft, said gear motor being operable when deenergized to maintain said housing stationary;

a lever pivotally supported by said frame in position to normally interfere with the rotation of said shaft;

a solenoid carried by said frame in position to effect pivotal movement of said lever to a noninterfering position to thereby release said shaft for rotation;

switch means carried by said frame and operably connected to selectively effect deenergization of said gear motor and said solenoid;

a threaded member mounted on said shaft and connected to rotate with said housing;

a nut threadedly engaged on said threaded member for axial movement therealong;

means operably connected to effect energization of said gear motor and said solenoid selectively;

a drive connection between said shaft and said nut to effect rotation of said nut on said threaded member when said shaft rotates, said nut operating after a predetermined number of revolutions of said shaft to actuate said switch member and thereby effect energization of said gear motor for recharging said spiral spring, said nut being moved in the opposite direction a predetermined distance upon rotation of said housing to thereby actuate said switch means to deenergize said gear motor; and,

means operably connected to effect energization and deenergization of said solenoid selectively.

5. In an operating device for operating a disconnect switch;

a frame;

an output shaft rotatably supported by said frame and operably connected to effect the operation of said disconnect switch in a closing movement and in an opening movement;

a housing supported on said shaft for rotation relative to said shaft;

a spiral motor spring coiled about said shaft and enclosed within said housing, said motor spring having one end connected to said housing and its other end connected to said shaft, the arrangement being such that rotation of said housing in one direction operates to charge said motor spring and said charged motor spring is operable to rotate said shaft in one direction for operation of said disconnect switch between an open or a closed position;

a gear mounted on said shaft for rotation relative to said shaft, said gear being secured to said housing for effecting its rotation in the one direction for charging said motor spring;

a gear motor carried by said frame and operably connected to drive said gear when energized to thereby rotate said housing for charging said motor spring, said gear motor being operable when deenergized to hold said gear and thereby said housing from rotating relative to said shaft;

a restraining lever pivotally carried by said frame in position to have one end thereof in interference with the rotational movement of said shaft;

a solenoid carried by said frame and operable when energized to effect the pivotal movement of said lever to a noninterfering position to free said shaft for rotation for operating said disconnect switch;

a biasing spring operably connected to return said lever to shaft interfering position to prevent further rotation of said shaft after said shaft has rotated an angular distance sufficient to operate said disconnect switch; and

means operably connected to supply a signal to said solenoid.

6. In an operating device for operating a disconnect switch in an opening and a closing movement for protecting a distribution system of which the disconnect switch is a part;

a frame;

an output shaft supported by said frame for rotational movement in one direction between a first position and a second position;

a housing mounted on said output shaft for independent rotation relative to said shaft;

a motor spring coiled around said output shaft and disposed within said housing, said motor spring having one end connected to said output shaft and its opposite end connected to said housing, the arrangement being such that rotation of said housing in one direction relative to said output shaft will operate to charge said motor spring and said housing also operates as a protective casing for confining said motor spring therein in case of structural failure thereof to afford personal protection;

a cam disc secured to said output shaft and presenting a pair of diametrically disposed stop abutments representative of the open and closed positions of said disconnect switch;

releaseable stop means supported by said frame in position of engagement with one or the other of said cam disc stop abutments to prevent operation of said output shaft;

a solenoid carried by said frame in position to release said stop means when energized; and

electrical means connecting said gear motor to the system said disconnect switch is arranged to protect, said electrical means including a pair of switches, one of which is actuated after said motor spring has operated said disconnect switch in three movements in sequence to effect the energization of said gear motor to recharge said motor spring, and the other of which is actuated to deenergize said gear motor after said motor spring has been fully charged for a subsequent series of disconnect switch operations.