US3600784A

US3600784A - Spring-loaded hotstick for manipulating electric cable connectors

Info

Publication number: US3600784A
Application number: US881564A
Authority: US
Inventors: Richard F Propst; Norman M Neagle
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1969-12-02
Filing date: 1969-12-02
Publication date: 1971-08-24
Anticipated expiration: 1988-08-24

Abstract

A hotstick for manipulating electric cable connectors is provided with a manually controlled, spring-actuated mechanism that makes the speed of circuit interrupting and circuit making operations independent of the speed at which a lineman moves the hotstick. To perform either a load making or load breaking function by connecting or disconnecting a cable connector module to, or from, a fixed terminal, a manually operated trigger on the hotstick is actuated after the hotstick is moved to position the module with respect to the terminal. Thus actuated, the trigger releases a spring loaded mechanism on the hotstick, which snaps the cable connector either toward or away from the fixed terminal to make or break the circuit with a minimum of arcing.

Description

United States Patent Inventors Richard F. Props! ltxinslom y Norman M. Neagie, Hickory, NC. Applv No. 881,564 Filed Dec. 2, 1969 Patented Aug. 24, 1971 Assignee General Electric Company SPRING-LOADED HOTS'I'ICK FOR MANlPULATlNG ELECTRIC CABLE CONNECTORS 10 Claims, 8 Drawing Figs.

05. Cl 29/203 H, 29/203 P Int. Cl HOlr 43/00, B25b 27/02 Field of Search 29/203, 203

H, 203 HM, 203 HC, 203 P [56] References Cited UNITED STATES PATENTS 3,098,289 7/1963 Demler 29/203 H 3,368,267 2/1968 Hedberg 29/203 H Primary Examiner-Thomas H. Eager Attorneys-Francis X. Doyle, Vale P. Myles, Frank L,

Neuhauser, Oscar B. Waddell and Joseph B. Forman ABSTRACT: A hotstick for manipulating electric cable connectors is provided with a manually controlled, spring-actuated mechanism that makes the speed of circuit interrupting and circuit making operations independent of the speed at which a lineman moves the hotstick. To perform either a load making or load breaking function by connecting or disconnecting a cable connector module to, or from, a fixed terminal, a manually operated trigger on the hotstick is actuated after the hotstick is moved to position the module with respect to the terminal. Thus actuated, the trigger releases a spring loaded mechanism on the hotstick, which snaps the cable connector either toward or away from the fixed terminal to make or break the circuit with a minimum of arcing.

' PATENTEU M1824 1971 SHEET 2 BF 3 w HM M M77 x SPRING-LOADED HOTSTICK FOR MANIPULATING I ELECTRIC CABLE CONNECTORS Prior to the present invention, various tools have been developed for enabling an electric utility lineman to safely handle high voltage cable and cable connecting components forming parts of an energized power system. In addition to insulated hotsticks that have cable holding jaws mounted on one of their ends, so a lineman can grasp an energized cable with the jaws and hold it at a safe distance from him, various loadbreak means have been built into hotsticks to reduce the danger of injury due to drawing a large arc when a circuit is opened under load. Usually, such hotstick-mounted loadbreak means, embody a pair of auxiliary contacts that are mounted to open with a snap-action in an arc-quenching chamber. Hotsticks of this type are suitable for sue with conventional disconnect switches or loadbreak cutouts in which the primary line contacts are exposed so that the auxiliary contacts on the hotstick can be connected in shunt relation with them prior to opening of the main contacts. However, such loadbreak mechanisms cannot be used to interrupt or make circuits that are completely insulated so that such an auxiliary connection cannot be made prior to circuit interruption. Thus, on underground power distribution systems, where all of the cable connections and disconnect points are necessarily completely insulated, such conventionally available loadbreak means are ineffective.

It is well recognized by those skilled in the art that arcing will occur between the relatively movable contacts of a high voltage electric circuit when the circuit is interrupted, or by prestrike when the circuit is being made. It is also well known that the amount of such arcing can be reduced by shortening the circuit making or breaking operation by rapidly moving the contacts together or apart. However, as experience with the operation of underground cable connectors has demonstrated, it is difficult to assure consistently rapid movement of a cable connector during circuit making or breaking operations to prevent it from being excessively damaged. This is so because with present manually operated hotsticks the speed of movement of the connector relative to a fixed terminal with which it is to be connected is entirely dependent upon the skill and manual reflexes of the lineman operating the hotstick. Due to the expense of high voltage cable connectors, it is very desirable to reduce the rate at which they are destroyed by arc erosion. Also, with the continuing growth of underground power distribution systems which utilize completely insulated cable connectors and line terminals, it would be of great advantage from a safety standpoint to develop a linemans hotstick that is operable to remove the speed of connector movement from control of a lineman after he has properly positioned the connector for movement to make or break a circuit.

Of course, for such a relatively automatic hotstick to have commercial acceptance, it must be light weight and portable so that it can be conveniently carried by a lineman and manipulated in the relatively confined spaces encountered in underground vaults of power distribution systems. Moreover, the operating components of such a hotstick must be suitably rugged to withstand the relatively rough handling they receive by being transported in utility trucks and by being continuously exposed to contaminants ordinarily encountered in field use. Moreover, such a hotstick must be capable of operating safely and reliably in all weather conditions because maintenance work on electric utility systems must frequently be carried out in inclement weather.

In one preferred form of our invention, a hotstick for manipulating electric power cable connector modules is provided with a manually controlled spring-actuated mechanism that is operable when triggered to move a cable connector with s snap-action into engagement with, or out of engagement from, a relatively fixed terminal. The hotstick includes a .pair of cable-holding jaws that operate to securely hold a cable connector in a predetermined position with respect to the hotstick handle. After a cable connector isthus secured, the hotsticks spring mechanism is then manually loaded and the hotstick is positioned in a suitable spaced relation with respect to a relatively fixed terminal. The spring-loaded mechanism is then triggered and the spring mechanism operates to move the cable termination module with a snap-action either into engagement with or out of engagement from the relatively fixed terminal.

A primary object of our invention is to provide an improved electric utility linemans hotstick that incorporates means for making or breaking an electric circuit with a snap-action.

Another object of our invention is to provide a hotstick with a spring-loaded mechanism that makes the speed of movement of a circuit making or interrupting operation independent from the skill and motor abilities of a lineman operatin the hotstick.

A further object of the invention is to provide a linemans hotstick that affords a load making or load breaking function while being relatively inexpensive to manufacture and still being suitable rugged and reliable for use in a wide variety of weather conditions.

Other objects and advantages of our invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view, partly in cross section, of an electric utility lineman s hotstick embodying the unique structural features of our invention.

FIG. 2 is a top elevation view of the invention described in FIG. 1.

FIG. 3 is a side elevation view, partly in cross section, of the hotstick illustrated in FIGS. 1 and 2, depicted in operating relation with respect to a relatively fixed electric terminal mounted on a transformer.

FIG. 4 is also a side elevation view, partly in cross section, showing our invention in operating relation with respect to a relatively fixed terminal mounted on a transformer tank, but showing the hotsticks spring-loaded mechanism in a discharged condition.

FIG. 5 is a fragmentary side elevation view, partly in cross section, showing a second embodiment of the invention depicted in the foregoing Figures, with the invention mounted in relation to a relatively fixed terminal on a transformer, aNd having its spring-loaded mechanism extended'to a position where it is prepared to remove a conductor termination from the relatively fixed terminal with a snap-action. 7

FIG. 6 is a fragmentary, side elevation view, partly in cross section, of the invention illustrated in FIG. 5, showing the trigger mechanism of the invention in a position just prior to effecting a triggering function that discharges the springloaded mechanism of the hotstick.

FIG. 7 is a fragmentary, perspective view showing a manual mechanism for loading the spring actuating device of the invention illustrated in the foregoing figures.

FIG. 8 is a fragmentary, perspective view illustrating a spacing means used with the embodiment of the invention depicted in FIG. 5.

Referring now to FIG. 1 of the drawing, there is shown an electric utility linemans hotstick 1 that is designed for use in manipulating electric power cable connector modules to connect such modules to relatively immovable electric terminals, or to disconnect the modules from such terminals. The hotstick 1 has an elongated body member 2 formed of a high-impact, corrosion resistant plastic material that has good electric insulating properties. However, as will become apparent from the following description, other suitable materials may be used to form the body member 2 as is well known by those skilled in this field. In order to releasably position an electric utility power cable connector module with respect to hotstick l, a holding means 3 comprising a pair of pivotally mounted

jaws

3A and 3B are mounted on a steel housing member 4 for reciprocal movement with this member 4. As is shown in FIG. 1, the member 4 is disc shaped, but any other suitable configuration may be employed in other embodiments of the invention. The connector module holding function of pivotally mounted

jaws

3A and 3B is controlled by manually operable means comprising a rotatable handle 5 at the opposite end of body member 2, and a steel link 6 (see FIG. 7) connected between handle 5 and the pair of

jaws

3A and 3B. A hollow, rigid tube 5A forms an integral part of body member 2 and serves to space rotatable handle 5 away from the central portion of body member 2, while also serving as hearing for rotatably mounting handle 5. The link 6 is operably connected to a gear. 7 .(FIG. 7) that meshes with a pair of gears (not shown) respectively mounted on

shafts

3C and 3D to cause these shafts and the

jaws

3A and 3B, which are mounted in fixed relation thereon, to rotate in direct response to rotation of handle 5. The other end of link 6 is splined into cooperating grooves (not shown) in the center of handle 5 so that link 6 can be moved with holding means 3 while maintaining its operative relationship withhandle 5. Of course, any other suitable manually operable means may be used to control the holding and releasing function of

jaws

3A and 3B without departing from the scope of our invention. As is apparent from the illustration showing in FIGS. 1 and ,7, when handle 5 is rotated'in one direction it is effective to move

jaws

3A and 3B apart to afford a connector module releasing function, and when handle 5 is rotated in the opposite direction, it moves jaws 3A and 38 together to effect a connector module holding function as will be described in greater detail below.

Mounted on body member 2 adjacent to one end thereof is an integral spacing means 8 for positioning the holding means 3 at least a predetermined distance from this end of the body member 2. In the preferred form of the invention illustrated in FIG. 1, the spacing means 8 comprise an elongated hollow portion of hotstick 1 in the form of two leg members 8A and 88 that are arranged to partially surround housing member 4 on at least two sides thereof. The exact function of spacing members 8A and 88 will be described more fully below. An elongated resilient member 9, in the form of a coil spring in this embodiment of the invention, is coupled in driving relation to holding means 3 by having one of its ends affixed to housing member 4 by welding or other suitable means. As can be seen in FIG. I, the other end of spring 9 is biased against a wall member 10 on which the

spacing leg members

8A and 8B aremounted by being fused thereto. Accordingly, when housing member 4 is moved toward wall member 10, it will compress spring 9 against wall member 10 so that the housing member 4 is biased toward the outermost end of spacing means 8.

. A manually operable loading'mechanism 11 comprising a inultitoothed ratch l2 and a cooperating pall 13 in the form of a steel rod are mounted on body member 2. A steel handle 13A is welded to the pall 13 so it can be moved relative l2, ratch l2, and mechanical coupling means 14 are connected between pall 13 and housing member 4. In the preferred form of the invention, the coupling means 14 comprises a hollow pipe of suitably strong insulating material, one end of which is connected to housing member 4 and the other end of which is connected to pall 13, as is perhaps best seen in FIG. 7. The manually operable loading mechanism 11 is effective to resiliently load spring 9 when the handle 13A is moved a predetermined distance away from one end of hotstick 1 and held in such a position by releasably latching pall 13 in engagement with one or more teeth of the ratch 12. This operation ofthe invention will be described in more detail below.

A trigger means 16 in the form of an elongated plastic handle is pivotally mounted on a pin 17 in body member 2 directly under the pall 13 when it is in its null position, i.e. when the I coil spring 9 is not loaded by its coupling to pal] 13. As will be clear from the following description, the trigger means 16 is operable to suddenly unlatch the pall 1 3, and thereby the holding means 3 to which it is directly coupled, to cause the holding means to be moved toward one end of hotstick l with a snap action movement responsive to the driving force exerted on it by coil spring 9.

A fuller understanding of our invention can be gained by considering its use to perform a closing operation to couple a cable connector module to a fixed terminal. Toward this end, reference is now made to FIGS. 2 and 3 of the drawing in which the hotstick l is shown in relation to a cable connector module 18 and a relatively immovable electric terminal 19 mounted on a transformer tank 20 (FIG. 3 only). In FIG. 2, cable connector module 18 is shown positioned within the

extended leg members

8A and 8B of spacing means 8 in a position it would be forced to assume prior to closing of the

jaws

3A and 3B of holding means 3 by rotating handle 5 in the manner described above. When

jaws

3A and 3B are closed in this fashion, they engage the eye portion 18A on module 18 and securely hold it so that the module 18 can be easily manipulated with hotstick 1.

As the invention is depicted in FIG. 2, the coil spring 9 is in its unloaded position and pall l3 rests at its null point in ratch 12. Now, assuming that it is desired to make a circuit between cable connector module 18 and the relatively fixed terminal 19 on transformer 20, the handle 13A of mechanical loading mechanism 11 is manually moved away from the end of hotstick 1 adjacent which module 18 is now held. It will be appreciated that the speed with which a circuit making function is subsequently accomplished in response to the driving action of spring 9, will be dependent on the degree of mechanical loading of this spring. Accordingly, pall 13 is positioned in any desirable one of the teeth on ratch 12 to adjust the loading of spring 9 to the degree desired. Since such loading variations for spring 9 would have to be worked out empirically for given applications of the invention, no further description of it will be given herein. However, it should be noted that spring 9 must be sufficiently loaded to prevent the conductor in module 18 from contacting the conductor in terminal 19 prior to release of spring 9 as hereinafter described.

With pall 13 resting behind a predetermined tooth of ratch 12, as shown in FIG. 3, the housing member 4 and holding means 3 are biased by spring 9 toward the end of hotstick 1 adjacent which module 18 is held. The lineman then moves the hotstick 1 into position adjacent relatively immovable electric terminal 19 by placing the end of spacing means 8 against transformer tank 20 around the base of terminal 19. In this position, an arc follower 21 that forms an integral part of the module 18 is inserted in a bore 19A in terminal 19. Thus, the module 18 is aligned and ready for rapid closure on terminal 19. At this point in the cable connecting operation, the lineman holds body member 2 securely in position and raises trigger means 16 by pivoting it around pin 17 until the pall 13 that overlies trigger'mea'ns 16 is raised out of contact with the teeth of ratch 12 and is thus freed to move rapidly forward in response to the driving action of coil spring 9. Following such a circuit-making operation, handle 5 is rotated to release eye 18A from

jaws

3A and 3B and the hotstick l is then withdrawn from around module 18. I

As noted at the outset, in addition to the type of load-making circuit forming function just described, our invention can also be utilized to remove a cable connector module from a relatively fixed terminal with an arc-reducing, snap-acting motion. An embodiment of our invention suitable for performing such a circuit disconnecting function is illustrated in FIGS. 5 and 6 of the drawing. Referring to FIG. 5, in which this embodiment of the invention is described using similar reference numbers to identify like parts as those illustrated earlier in FIGS. l-4, this second embodiment of the invention will be described. Thus, hotstick 1 is shown having a further spacing means 21 positioned adjacent its outermost end. The spacing means 21 comprises a cylinder having a plurality of slotted

apertures

21A, 21B and 21C (See FIG. 8) formed therein. The largest of these apertures 21A is formed adjacent the bottom portion of cylinder 21 and is wide enough to easily accommodate a cable terminal module 18, as shown in FIG. 5. The other apertures 21B and 21C afford visibility for a lineman to observe the relative position of holding means 3 with respect to cylinder 21.

In order to position spacing means 21 in a desired location on spacing leg members 8A and 88, a pair of suitable detents 22 and 23 are mounted on

spacing members

8A and 8B, as seen in FIG. 5. It will be appreciated by those skilled in the art that in this application of the invention, the length of spacing means 21 must be carefully predetermined so that when it is mounted in position against abutments 22 and 23, as shown in FIG. 5, the holding means 3 are accurately positioned to engage an eye portion 18A of module 18 connected to fixed terminal 19, after coil spring 9 has been moved to its extended position as shown. However, in alternative embodiments of the invention, the abutments 22 may be made movable, for example, by providing a plurality of linearly spaced holes 22A in members 8A and 88 to adjust the length of spacing means 21 with respectto various different sized modules 18. Of course, other means for adjusting the position of spacing means 21 relative to leg members 8A and 88 may be provided, such as providing detents on spacing means 21 to lock with abutments 22 and hold it in a plurality of different predetermined arrangements. All such modifications are deemed to be within thescope of our invention.

In the operation of this form of the invention, the manual loading mechanism 11 is loaded by moving handle 13A in a reverse direction with respect to the direction in which it would be moved to effect a circuit making operation as described above. Accordingly, handle 13A is manually moved toward the forward end of hotstick 1 until pall 13 is engaged by one or more teeth of ratch 12 adjacent the forward end of this ratch. In this position of pall 13, the holding means 3 is positioned adjacent the outermost end of body member 2, and integral spacing means 8 (without spacing means 21); then, handle 5 is rotated in a clockwise direction to close

jaws

3A and 3B of holding means 3 on eye 18A of module 18. The lineman then securely holds hotstick 1 so that spacing means 21 rests tightly against the transformer tank 20. Next, trigger means 16 is pivoted to the position shown in FIG. 6, so-that pall 13 is disengaged from the teeth of ratch 12 and is freed to be driven rapidly back toward its null position by the tensioning action of coil spring 9. Due to the direct mechanical coupling of link 14 between pall 13 and housing member 4, v

the cable module 18 is snapped away from relatively immovable terminal 19 to interrupt the electric circuit. Following such a circuit interrupting operation, the lineman mov'es hotstick 1 and spacing means 21 away from transformer tank 20.

' It will be apparent from the foregoing description that other modifications and embodiments of our invention may be made by those skilled in the art based upon the teaching of the invention presented herein and it is our intention to encompass all such modifications within the true scope of the invention. For example, it will be apparent that ratch 12 may be made in the form of a toothed disc and pall 13 could be a pivotally mounted'click that is crank operated to move member 14, or a flexible counterpart for it, to a position such that spring 9 is thereby loaded. ln addition, it will be apparent that different housing arrangements may be constructed for body member 2, so that the relatively movable parts of the hotstick are more completely shielded thereby to limit the risk of an operator being injured by these parts.

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

l. A hotstick for manipulating electric power cable connector modules to connect the modules to relatively immovable electric terminals, said hotstick comprising an elongated body member, holding means movably mounted adjacent one end of said body member for releasably holding a connector module, spacing means on said one end of the body member for positioning the holding means at least a predetermined distance from said one end, manually operable means for controlling holding and releasing functions of said holding means, a resilient member coupled in driving relation to said holding means, a manually operable loading mechanism coupled to said resilient member and effective to resiliently load said resilient member by moving it a predetermined distance away from said one end and releasably latching it in such a displaced position, trigger means for releasing the latching of the holding means against the biasing force exerted on it by the resilient loading of said resilient member when said resilient member is moved away from said one end, said trigger means being operable to suddenly unlatch said holding means thereby causing said holding means to be moved toward said one end with a snap action responsive to the driving force exerted on it by said resilient member.

2. A hotstick as in claim 1 wherein said holding means comprises a pair of jaws pivotally mounted on a housing member, and said spacing means comprises an elongated hollow portion of said hotstick arranged to partially surround said housing member on at least two sides thereof.

3. A hotstick as in claim 2 wherein said manually operable means for controlling functions of the holding means comprises a handle rotatably mounted adjacent the end of said hotstick remote from said one end, and a link connected between said handle and said pair of pivotally mounted jaws, said link being operably connected to said jaws to move them toward one another to afford a connector module holding function when the handle is rotated in one direction and being further effective to move said jaws apart to afford a module releasing function when the handle is rotated in an opposite direction.

4. A hotstick as in claim 2 wherein said resilient member comprises a coiled spring mounted between said housing member and the end of said hollow portion of the hotstick remote from said one end.

5. A hotstick as in claim 4 wherein said manually operable loading mechanism comprises a multitoothed ratch, a pall adapted to be held in position by one or more teeth of the ratch, mechanical coupling means between said pall and said housing member that are operable to compress said spring when the pall is manually moved away from said spring, and means for manually moving said pall into latching engagement with said one or more teeth of the ratch.

6. A hotstick as in claim 5 wherein said trigger means comprises a lever pivotally mounted on the hotstick and manually pivotable into engagement with said loading mechanism to cause said pall to be unlatched from the teeth of said ratch, whereby the coil spring drives the housing member toward said one end of the hotstick with a snap action,

7. A hotstick for manipulating electric power cable connector modules to connect and disconnect the modules to and from relatively immovable electric terminals, said hotstick comprising an elongated body member, holding means movable mounted adjacent one end of said body member for releasably holding a connector module, spacing means on said one end of the body member for positioning the holding means at least a predetermined distance from said one end, manually operable means for controlling holding and releasing functions of said holding means, a resilient member coupled in driving relation to said holding means and operable when resiliently loaded to drive the holding means toward said one end, a manually operable loading mechanism coupled to said resilient member and effective to resiliently load said resilient member by moving it a predetermined distance relative to said one end and releasably latching it in such a displaced position, trigger means for releasing the latching of the holding means against the biasing force exerted on it by the resilient loading of said resilient member when said resilient member is moved relative to said one end, said trigger means being operable to suddenly unlatch said holding means thereby causing said holding means to be moved with a snap action responsive to the driving force exerted on it by said resilient member.

8. A hotstick as in claim 7 including an extension element that is adapted for mounting on said one end of the body member in fixed relation thereto and which extends an additional predetermined distance beyond said one end, said extension element being effective when mounted on said one end of the body member to space the holding means from a relatively fixed terminal by at least said additional predetermined distance.

9. A hotstick as in claim 8 wherein said loading mechanism includes a two-way ratch having two sets of teeth and a pal] adapted to be held in position by one or more teeth of the ratch, mechanical coupling means between said pall and said housing member that are operable to resiliently load said resilient member when the pall is moved relative to said resilient member and means for manually moving said pall into latching engagement with said one or more teeth of the ratch.

10. A hotstick as in claim 9 wherein said means for that position by one of the teeth of said ratch, said'holding means being moved away from said one end with a snap action when the trigger means is operated.

Claims

1. A hotstick for manipulating electric power cable connector modules to connect the modules to relatively immovable electric terminals, said hotstick comprising an elongated body member, holding means movably mounted adjacent one end of said body member for releasably holding a connector module, spacing means on said one end of the body member for positioning the holding means at least a predetermined distance from said one end, manually operable means for controlling holding and releasing functions of said holding means, a resilient member coupled in driving relation to said holding means, a manually operable loading mechanism coupled to said resilient member and effective to resiliently load said resilient member by moving it a predetermined distance away from said one end and releasably latching it in such a displaced position, trigger means for releasing the latching of the holding means against the biasing force exerted on it by the resilient loading of said resilient member when said resilient member is moved away from said one end, said trigger means being operable to suddenly unlatch said holding means thereby causing said holding means to be moved toward said one end with a snap action responsive to the driving force exerted on it by said resilient member.

6. A hotstick as in claim 5 wherein said trigger means comprises a lever pivotally mounted on the hotstick and manually pivotable into engagement with said loading mechanism to cause said pall to be unlatched from the teeth of said ratch, whereby the coil spring drives the housing member toward said one end of the hotstick with a snap action.

9. A hotstick as in claim 8 wherein said loading mechanism includes a two-way ratch having two sets of teeth and a pall adapted to be held in position by one or more teeth of the ratch, mechanical coupling means between said pall and said housing member that are operable to resiliently load said resilient member when the pall is moved relative to said resilient member and means for manually moving said pall into latching engagement with said one or more teeth of the ratch.

10. A hotstick as in claim 9 wherein said means for manually moving said pall is operable to move the pall toward said extension element approximately said additional predetermined distance, whereby said holding means is positioned adjacent said one end of the hotstick when the pall is moved said additional predetermined distance and latched in that position by one of the teeth of said ratch, said holding means being moved away from said one end with a snap action when the trigger means is operated.