GB2228466A - Unwinding device - Google Patents

Abstract

A rotatable unwinding device which can be introduced to an object to be rotated by relative displacement of the device and object in a direction generally transverse to the rotational axis of the device has circular body (10) having two semi-circular parts (10a, 10b), each carrying one of a pair of jaws (44a, 44b not shown) whose jaw axis coincides with the central axis of the circular body (10). The body parts (10a, 10b) are separable by distance A to allow access to the jaws (44a, 44b) in a direction radially of the body axis. In order to enable the device to be rotated, the body (10) is held between an array of opposed inner and outer pulleys or gears 20a, 20b, 20c. To unwind wire bindings holding conductors to pylons, the device is located on insulated handles 34. Handle 16 rotates to separate body parts 10a, 10b. Motor 30 rotates the closed body parts about the conductor to unwind binding. <IMAGE>

Description

DESCRIPTION ROTATING VICE The present invention is concerned with a rotating vice which can be used, inter alia, for the unwrapping of insulator binds on overhead electrical distribution systems.

In the electrical supply industry, many overhead conductors are attached to pylon or gantry mounted insulators by the use of wires which are wrapped over the insulator and around the conductor at two opposite sides of the insulator in the manner of bindings (known as "handbinds" in the art). The conventional manner of applying and removing these "handbinds" is actually by hand. Removal of the handbinds, for example, requires unwrapping the binding wire in a circular motion around the conductor. It is often required to disconnect the conductor from the insulators whilst still fully energised at, for example, Ii kV. The conventional technique for achieving this has involved the use of two tools one with a hook on the end and the other a wire cutter, both mounted on an insulated pole of several metres in length.The hooked tool is used to unpick the tail of the binding wire and then unwrap the binding wire from the conductor. The tail of the binding wire that has been unwrapped must be kept short by the use of the cutters so as to prevent any possible contact with the pylon, gantry or other conductors. This is an arduous and time consuming operation requiring frequent cutting of the tail of the binding wire.

Once the binding wire has been unwrapped, the conductor can be moved by the use of insulated poles to provide access to the insulator etc.

It is the principal object of the present invention to simplify and greatly speed up the present system of unbinding by eliminating the unpicking and manual rotation of the binding wire by the conventional hooked pole. It is also to eliminate the need to cut the tail off the binding wire during the unwrapping operation whereby to thus reduce the possibility of the wire coming into contact with the pylon, gantry or other conductors.

In accordance with the present invention in its broadest aspect, there is provided a rotating vice which is adapted to be introduced to an object to be rotated by relative displacement of the vice and object in a direction generally transverse to the rotational axis of the vice.

By not having to be introduced to the object along the axis of rotation, as is the case with a conventional rotating vice or chuck, the present arrangement permits an object to be gripped and rotated around a supporting shaft or the like where the ends of such shaft or the like are not free.

In a preferred embodiment, the vice has a generally circular body comprising two generally semi-circular body parts, each of which carries a respective one of a pair of jaws whose jaw axis coincides with the central axis of the circular body, the two body parts being interconnected such as to enable them to be separated selectively by a limited distance and in their separated condition, to allow access to said jaws in a direction radially of the body axis.

In order to enable the vice to be rotated, the circular body is held between an array of opposed inner and outer pulleys or gears which engage the body at spaced locations in a region occupying less than 1800 of the body.

Preferably, two such pulleys or gears engage a radially inwardly facing circular track formed in the two semi-circular body parts and a third pulley or gear, disposed equidistantly from the two first mentioned pulleys or gears, engages a radially outwardly facing track disposed on the outer periphery of these body parts. In a convenient embodiment, the latter (third) pulley or wheel is adapted to be selectively driven by a power source for rotating the vice body.

As a result of this means of rotatably supporting the body, if the body is stopped such that the supporting region lies wholly on one of the semicircular parts, then the other semi-circular part can be displaced relative to the one part so as to open the vice and enable access to the jaws.

The vice body is preferably mounted at one end of an elongate electrically insulated support, such as a fibre-glass pole, the pulleys or gears being mounted rotatably on a rigid fixed mounted at said one end of the pole.

The pulleys or gears can be rotated directly by means of a rotary power source disposed at said one end of the pole or, more usually, indirectly by a power source disposed at the opposite end of the pole and connected by means of a rigid or flexible coupling. In one embodiment, for example, the power source can be an electrical motor coupled to the pulleys or gears by a rigid shaft or flexible drive.

The means connecting together the two halves of the circular body preferably includes a screw-shaft which can be rotated selectively from a remote location for opening and closing the vice. In the simplest embodiment, this remote control is achieved using a socket/nut mounted on one end of a rotatable shaft and selectively connectible to a nut/socket attached to the screw-shaft.

It will be appreciated that the invention is not restricted to the three point support provided by the three pulleys or gears mentioned above since other combinations of pulleys or gears could equally well be used, provided that they engage the body over less than the specified 1800 to enable the vice to be opened in the manner described.

The invention is described further hereinafter, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a front perspective view of one embodiment of a rotary vice in accordance with the present invention, having an elongate control and drive structure; and Fig. 2 is a rear perspective view of the rotary vice of Fig. 1, showing only a part of the control and drive structure.

The embodiment shown in the drawings comprises a generally circular body in the form of a bobbin 10 comprising two generally semi-circular component parts 10a, lOb. The bobbin parts 10a, lOb are interconnected firstly by a pin 12, which is fixed rigidly to one part 10a or 10b and which slides snugly in a bore (not visible in the drawings) in the other part 10a or 10b.

The two bobbin parts 10a, lOb are also interconnected by a rotatable screw shaft 14, disposed parallel to the pin 12 and on the same side of the central axis of the bobbin as the pin 12, the arrangement being such that rotation of the screw-shaft causes the two bobbin parts 10a, lOb to be displaced between an open position, as shown in the drawings, in which the bobbin parts are separated by a uniform gap A, and a closed position in which the bobbin parts lie in abutment to define a circular outer profile. Adjustment of the bobbin parts between their open and closed positions is achieved by means of a control shaft 16, as described further hereinafter.

As shown in Fig. 1, each of the two bobbin parts 10a, 10b defines a respective, radially inwardly facing, semi-circular recess 18a, 18b which, in the closed position of the bobbin, define together a closed circular track 18. The bobbin is supported for rotation by means of a pair of pulley wheels 20a, 20b which run within the track 18 and a third pulley wheel 20c which engages an outer peripheral track 22 on the bobbin outer surface, all three pulley wheels 20a, 20b, 20c being carried by a rigid support plate 24. As shown in Fig.

1, the bobbin is thus held firmly at three points on one half only of the bobbin. Thus, with the bobbin in its closed position (i.e. when the track 18 is completed), forced rotation of the wheel 18 (and/or the wheels 20a, 20b) will cause the bobbin to be rotated about its central axis through any number of complete or partial revolutions.

In this embodiment, the pulley wheel 20c is arranged to be rotatable by means of a bevel gear 26 and an electrically non-conductive shaft 28 driven selectively by an electric motor 30.

The support plate 24, which would normally be made of metal for strength and rigidity, is coupled by a suitable bracket 32 to one end of a main support pole 34 which is also an electrically insulated material. Also journalled in the bracket 32 is one end of the shaft 16, which is again made of an electrically insulating material. The shaft 16 can be displaced longitudinally so that a socket 38 on said one end can be manoeuvred onto a nut 40 (see Fig. 2) fixed rigidly to the rotatable screw-shaft 14 so that the latter shaft can be rotated for opening or closing the two parts of the bobbin 10. Of course, this can only happen when the bobbin is itself stationary and when the bobbin parts have been brought to rest in a position in which the nut 40 is lined up with the socket 38.In this embodiment, the opposite end of the shaft 16 is fitted with a handle 42 for manually controlling the action of the shaft 16.

For gripping a component or object to be rotated by the vice, the two bobbin parts 10a, 10b are fitted with respective jaws 44a, 44b. In this embodiment, the jaw part 44b is fixed rigidly to the bobbin part lOb but the jaw part 44a is spring loaded in a rectangular slot 46 in the bobbin part 10a so as to be biassed towards the jaw part 44b. However, the jaw part 44a is constrained from moving beyond the diametral position shown in Fig.

2 by the length of two screws 60 by which it is coupled to the bobbin part 10a. The two jaw parts 44a, 44b each have a respective serrated central recess which, when the bobbin is in its closed condition, lie coaxially around the central rotational axis of the bobbin.

For guiding an object or component to be rotated accurately to the jaws, the jaw part 44b carries a hooked guide 50 which defines a slot 52 whose inner, closed end lies on said central rotational axis of the bobbin.

In use, the bobbin parts are first brought to their separated condition (Figs. 1 and 2) by engaging the socket 38 with the nut 40 and rotating the screw-shaft 14 by means of the shaft 16. The bobbin 10 is then manoeuvred using the pole 34 so that a component or object to be rotated enters the space A between the bobbin parts 10a, lOb from the right (as viewed in Fig.

1) so as to be guided by the hooked guide 50 into alignment with the central rotational axis of the bobbin. It will be appreciated that this is possible because both of the connections 12, 14 between the component parts of the bobbin lie on one side only (left hand side in Fig. 1) of the central rotational axis of the bobbin. In the case of "handbinds" of the type described initially, the hooked guide is adapted to engage the free end of the binding wire. The shaft 16 is then rotated in the opposite direction to close the bobbin parts together and thereby clamp the binding between the jaw parts 44a, 44b. The shaft 16 is displaced axially to withdraw the socket from the nut 40 whereby the bobbin is free to be rotated.Energisation of the motor 30 can then rotate the bobbin by means of the pulley wheel 20c, bevel gears 26 and shaft 28 so as to unwind the binding from the conductor about which it is wrapped i.e. by rotating it in a direction opposite to that with which the binding wire was originally applied. This causes the binding wire to bird cage and unravel. The hooked guide 50 is so sized that during the rotation it does not come into contact with the conductor, and hence does not damage the conductor. When unwinding has been completed, the bobbin parts and jaws can be separated using the shaft 16 to enable the vice to be withdrawn from the conductor.

It will be appreciated that the use of a spring jaw allows the bobbin to close completely for rotation and permits various sizes of item to be gripped. The jaw set can easily be changed to accommodate other type/ sizes of object to be gripped. In the present embodiment, the vice is arranged to be opened, closed and rotated remotely at the bottom end of the pole 34.

For other applications, it could be arranged to be opened, closed and rotated locally using power sources disposed on the pole 34 close to the bobbin 10 and controlled remotely, e.g. electrically, from a control means at the bottom end of the pole 34. If the conductor is not energised the device could be used without any insulated rods 16,28,34.

Although described above as being rotated by rotation of the pulley wheel 20c, it will be appreciated that the bobbin can be rotated by a pulley and/or gears acting on either the outside, inside or side wall of the bobbin.

Although rotated by an electric motor 30 in the described embodiment, the shaft 28 for rotating the bobbin could be driven by other types of motor or by hand. Likewise, although rotated in the described embodiment by hand, the shaft 16 could be motor driven.

Other methods of rotating the bobbin remotely can be used, for example by the use of gears and/or pulleys and/or flexible rotating drive means. For remote turning of the bobbin with flexible rods, the bevel gears 26 are kept together by the use of a frame which supports the gear shafts rigidly. As mentioned above, the bobbin can be turned locally by the use of pulleys and/or gears and a local power source and not using drive shafts to transmit the rotating power over a distance.

It will be appreciated that, as a result of the insulated shafts 16, 28, 34, the rotary vice described herein allows the handbind to be removed while an overhead conductor is still energised.

Claims (11)

1. A rotating vice which is adapted to be introduced to an object to be rotated by relative displacement of the vice and object in a direction generally transverse to the rotational axis of the vice.

2. A rotating vice as claimed in claim 1, having a generally circular body which comprises two generally semi-circular body parts, each of which carries a respective one of a pair of jaws whose jaw axis coincides with the central axis of the circular body, the two body parts being interconnected such as to enable them to be separated selectively by a limited distance and, in their separated condition, to allow access to said jaws in a direction radially of the body axis.

3. A rotating vice as claimed in claim 2, wherein, in order to enable the vice to be rotated, the circular body is held between an array of opposed inner and outer pulleys or gears which engage the body at spaced locations in a region occupying less than 180 of the body.

4. A rotating vice as claimed in claim 3, wherein two such pulleys or gears engage a radially inwardly facing circular track formed in the two semi-circular body parts and a third pulley or gear, disposed equidistantly from the two first mentioned pulleys or gears, engages a radially outwardly facing track disposed on the outer periphery of these body parts.

5. A rotating vice as claimed in claim 4, wherein the third pulley or wheel is adapted to be selectively driven by a power source for rotating the vice body.

6. A rotating vice as claimed in claim 3, 4 or 5, wherein the vice body is mounted at one end of an elongate electrically insulated support, such as a fibre-glass pole, the pulleys or gears being mounted rotatably on a rigid fixture mounted at said one end of the pole.

7. A rotating vice as claimed in claim 3, 4, 5 or 6, wherein the pulleys or gears are rotatable directly by means of a rotary power source disposed at said one end of the pole or indirectly by a power source disposed at the opposite end of the pole and connected by means of a rigid or flexible coupling.

8. A rotating vice as claimed in claim 7, wherein the rotary power source is an electrical motor coupled to the pulleys or gears by a rigid shaft or flexible drive.

9. A rotating vice as claimed in any of claims 2 to 8, wherein the means connecting together the two halves of the circular body includes a screw-shaft which can be rotated selectively from a remote location for opening and closing the vice.

10. A rotating vice as claimed in claim 9, wherein the remote control is achieved using a socket/nut mounted on one end of a rotatable shaft and selectively connectible to a nut/socket attached to the screw-shaft.

11. A rotating vice substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

11. A rotating vice substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows

1. A rotating vice which is adapted to be introduced to an object to be rotated by relative displacement of the vice and object in a direction generally transverse to the rotational axis of the vice, the rotating vice having a generally circular body which comprises two generally semi-circular body parts each of which carries a respective one of a pair of jaws whose jaw axis coincides with the central axis of the circular body, the two body parts being interconnected such as to enable them to be separated selectively by a limited distance and, in their separated condition, to allow access to said jaws in a direction radially of the body axis.

2. A rotating vice as claimed in claim 1, in which the jaws are sprung loaded to allow different sized objects to be clamped while allowing the semi-circular parts to close together to form a continuous circular body.

3. A rotating vice as claimed in claim 1 or 2, wherein, in order to enable the vice to be rotated, the circular body is held between an array of opposed inner and outer drive and thrust parts which engage the body at spaced locations in a region occupying less than 1809 of the body.

4. A rotating vice as claimed in claim 3, wherein two such drive and thrust parts engage a radially inwardly facing circular track formed in the two semi-circular body parts and a third drive part, disposed between the two first mentioned thrust parts, engages a radially outwardly facing track disposed on the outer periphery of these body parts.

5. A rotating vice as claimed in claim 4, wherein the third drive part wheel is adapted to be selectively driven by a power source for rotating the vice body.

6. A rotating vice as claimed in claim 3, 4 or 5, wherein the vice body is mounted at one end of an elongate support, such as an electrically insulated fibre-glass pole, the drive and thrust parts being mounted rotatably on a rigid fixture mounted at said one end of the pole.

7. A rotating vice as claimed in claim 3 4, 5 or 6, wherein the drive part is rotatable directly by means of a rotary power source disposed at said one end of the pole or indirectly by a power source disposed at the opposite end of the pole and connected by means of a rigid or flexible coupling.

8. A rotating vice as claimed in claim 7, wherein the rotary power source is a motor coupled to the drive part by a rigid shaft or flexible drive.

9. A rotating vice as claimed in any of claims 2 to 8, wherein the means connecting together the two halves of the circular body includes a screw-shaft which can be rotated selectively from either a remote or local location for opening and closing the vice.

10. A rotating vice as claimed in claim 9, wherein the remote control is achieved using a socket/nut mounted on one end of a rotatable shaft and selectively connectible to a nut/socket attached to the screw-shaft.