The present invention also relates to a central part for a coil which is formed of a continuous flexible object and has a cylindrical outer side, a cylindrical inner side and a central hole running axially through it that is surrounded and defined by said cylindrical inner side, which central part is designed for insertion into the central hole of the coil to be activated for cooperation with the inner side of the coil.

EP 0 525 093 B1 describes a tool for producing a rotatable unit from a coil of an object of the type described, the coil being produced by utilizing a supporting sleeve of cardboard or boards, for instance.

The boards may be separated by gaps. When the object is coiled a parcel of coils provided with sleeves and binding means for delivery to the application site where said tool is available for assembling such parcels. The sleeve ensures that the coil retains its shape when being handled. The known tool consists of a connecting rod and two annular side supports or end elements assembled at right angles thereto, provided with concentric, fixed centring elements for engagement with the inside of the coil. The tool and the coil provided with a sleeve form a unit rotatable about an axis of rotation that is defined by the connecting rod. The rotatable unit is provided with a bearing shaft that is introduced through the connecting rod, after which the rotatable unit with the bearing shaft is placed in an uncoiling trestle so that the unit is rotatably journalled on the bearing shaft.

Nowadays plastic hosing is supplied in the form of coils without such a sleeve or core. In such coreless coils the inner layer of turns of the plastic hose defines the central hole running through the coil, and thus the inner side of the coil. Omission of the core reduces the cost of the coil and there is no core to take care of at the work site after the plastic hosing has been uncoiled. An example of the use of coreless coils of plastic hosing is for laying out such plastic hosing for subsequent drawing of fibre optics cable, the plastic hosing then constituting a protective casing for the fibre optic cable. The plastic hosing is normally coiled in the production plant where it is manufactured. After coiling the coil is provided with a number of binding strips running around the coil through the central hole, after which the bound coil is transported to a work site where the plastic hosing is to be laid. A tool is generally provided at the work site, consisting of a bearing shaft in the central hole of the coil, after which the coil and its bearing shaft is placed on an uncoiling trestle and the binding strips around the coil are cut. The diameter of the bearing shaft must be slightly less than the diameter of the central hole of the coil so that the bearing shaft can be inserted into the central hole of the coil. An injurious clearance thus appears between them since the coil will slide uncontrollably on the bearing shaft during uncoiling. Uncoiling will therefore occur unevenly and in jerks, which in turn gives rise to disturbances in the uncoiling and thus undesirable interruptions. During the previous coiling procedure the central hole of the finished coil acquired a circular or substantially circular cross section. The binding means hold the layers of plastic hosing together but do not have any noticeable stabilizing effect on the roundness of the coil. Due to the lack of a supporting core, the coil is often deformed while being transported to the

work site, particular if it is transported with the central hole lying horizontally, whereupon the coil is compressed so that, upon arrival at the work site, its central hole is no longer circular. Both the inside and the outside of the coil are thus non-circular. The cross section of the central hole may in certain cases be strongly elliptical or oval. Due to the rigidity of the plastic hosing it is impossible to restore the circular cross section of the central hole on site by means of mechanical force. A non-circular cross section of the central hole of the coil therefore causes additional problems during uncoiling since the diameter of the bearing shaft for such a non-circular coil must be less than the smallest diameter of the central hole. Varying clearance, seen peripherally, therefore occurs between the non-circular inner wall of the coil and the bearing shaft, thus causing the coil to jump on the bearing shaft during uncoiling, which in turn causes the coil to have an even greater tendency to slide uncontrollably on the bearing shaft. To avoid such deformation of the coil and thus to a certain extent reduce the problem of its uncontrolled sliding on the bearing shaft, attempts have been made to reinforce the binding during coiling by stopping coiling at regular intervals, applying extra binding strips through the central hole and round the layers of plastic hosing already coiled, and then continuing the coiling procedure. However this has not prevented deformation of the coil to any noticeable extent, and in any case the problem first described with such a coreless coil still remains. The extra binding strips entail increased material costs and increasing manufacturing costs for the coreless roll. The time required and cost of uncoiling also increase since this must be discontinued at regular intervals in order to cut the extra, internal binding strips, remove and collect them.

The object of the present invention is to eliminate the problems mentioned above and to provide a tool that enables simple and reliable handling of a coil of a continuous flexible object, primarily in connection with uncoiling the object from the coil.

The tool in accordance with the invention is characterized in that it comprises a central part for insertion into the central hole of the coil to be activated for cooperation with the inner side of the coil, which central part comprises -an elongate body having two opposite ends and defining a centre line that extends through said ends, -a central bearing means defining an axis of rotation for rotation of the tool, which axis of rotation coincides with the centre line of the body, -a plurality of peripheral engagement members distributed around said centre line and located at a distance therefrom, -a carrying member connected to the body and carrying the engagement members, and -one or more power members to actuate the engagement members in direction from said centre line and towards the inner side of the coil in order to bring the engagement members into friction engagement with the inner side of the coil to form a unit out of the central part and the coil, said unit being rotatable about said axis of rotation.

The central part in accordance with the invention is characterized in that it comprises -an elongate body having two opposite ends and defining a centre line that extends through said ends, -a central bearing means defining an axis of rotation for rotation of the tool, which axis of rotation coincides with the centre line of the body,

-a plurality of peripheral engagement members distributed around said centre line and located at a distance therefrom, -a carrying member connected to the body and supporting the engagement members, and -one or more power members to actuate the engagement members in direction from said centre line and towards the inner side of the coil in order to bring the engagement members into friction engagement with the inner side of the coil to form a unit out of the central part and the coil, said unit being rotatable about said axis of rotation.

The invention will be described in more detail in the following with reference to the drawings.

Figure 1 shows in perspective a coil of a continuous object in the form of a plastic hose, provided with strips.

Figure 2 shows in perspective parts of a central part or hub-forming device of a tool in accordance with a first embodiment of the invention.

Figure 3 is a view from above of the coil and the central part in accordance with Figures 1 and 2, respectively, the central part having been inserted into the central hole of the coil and being in non-active state.

Figure 4 is a view from above of the coil and central part in accordance with Figure 3, where the central part is in an active state to produce a rotatable unit.

Figure 5 shows in perspective an uncoiling trestle and the rotatable unit shown in Figure 4 in position for lowering into the uncoiling trestle, the unit being provided with a bearing shaft.

Figure 6 shows in perspective the uncoiling trestle, bearing shaft and the rotatable unit as shown in Figure 5, where the rotatable unit is journalled by means of the bearing shaft in the uncoiling trestle, ready for uncoiling.

Figure 7 is an exploded view of a coil of plastic hosing in accordance with Figure 1, and parts of a tool in accordance with a second embodiment of the invention in starting positions to bee assembled.

Figure 8 shows in perspective a rotatable unit of coil and tool parts as shown in Figure 7.

Figures 9 and 10 show views from above of a central part of a tool in accordance with a second embodiment of the invention in inserted position in a coil, the central part being in non-active and active state, respectively.

Figures 11 and 12 show in different perspectives a central part of a tool in accordance with a third embodiment of the invention in non-expanded state.

Figure 13 shows a section of a bearing and engagement part of the central part as shown in Figure 11.

Figures 14 and 15 show in different perspectives the central part shown in Figure 11 and Figure 12, respectively, in freely expanded state (with no counter-action from the coil).

Figure 16 is a view from above of a coil as shown in Figure 1 and a central part inserted therein, in non-expanded state.

Figure 17 is a view from above of the coil and central part shown in Figure 16, the central part have been expanded to form a rotatable unit with the coil.

Figure 1 shows schematically a coil 1 formed of a continuous, flexible object 2, without the use of a stable inner sleeve or core. After manufacture the coil 1 is provided with a plurality of binding strips 3 that hold the turns of the object 2 together during storage and transport of the coil to the application site as a parcel. The coil 1, which is thus cylindrical, has a cylindrical outer side 4, a cylindrical inner side 5 and a central hole 6 running through it which is surrounded and defined by the cylindrical inner side 5. The cylindrical inner side forms a relatively stable wall.

The coil 1 also has two parallel, flat end sides 7,8.

Examples of continuous, flexible objects are cable, line, wire, wire cable, rope, cord, ribbon, chain, uninsulated conductors for electrical overhead lines and hosing, e. g. plastic hosing to protect fibre optics cable.

Figure 2 shows schematically parts of a tool designed to be brought into engagement with a coil 1 of the type shown in Figure 1. The tool, intended for repeated use, comprises a central part or hub-forming device 9 for the coil 1, the central part 9 being inserted into the central hole 6 of the coil 1 to be activated for cooperation with the inner side 5 of the coil 1. In its non-activated state, therefore, the central part 9 has a cross-sectional dimension that is less than the smallest cross-sectional dimension of the central hole 6 so that the central part 9 can freely, that is to say easily and without difficulty, be inserted into and received by the central hole 6 of the coil 1. From Figures 3 and 4 it can be seen that the coil 1 is deformed so that the central hole 6 has a non-circular cross section. The inner side 5 of the coil 1 is thus not round, i. e. it is non-circular.

The central part 9 comprises an elongate, central, stable body 10 forming a stand with two opposite ends 11,12 and defines a centre line 13 that extends through the ends 11,12. The central part 9 also has a central bearing means 14, a plurality of peripheral engagement members 15, a carrying member 55 and a plurality of power members 16 (omitted in Figure 2, see Figures 3 and 4). The bearing means 14 defines an axis of rotation for the tool, which axis of rotation will coincide with the centre line 13 of the central body 10. The bearing means 14 is thus concentric with this centre line 13.

The carrying member 55 is joined to the central, stable body 10 and carries the engagement members 15 which are uniformly distributed around and spaced from the centre line 13. The power members 16 is arranged to actuate the engagement members 15 away from the centre line 13 and towards the inner side or inner wall 5 of the coil 1 to bring the engagement members 15 into friction engagement with the inner wall 5 of the coil, producing a unit 17, comprising the central part 9 and coil 1, which is rotatable about said axis of rotation coinciding with the centre line 13.

In the embodiment shown in Figure 2 the stable body 10 consists of an oblong, central, axially arranged tube 18 forming a hub and having a hole 19 running through it.

The inside of the tube 18 is cylindrical in shape. The carrying member 55 is rigidly fixed to the tube 18 and comprises two parallel end rings 20,21 arranged concentrically with the tube 18 and at right angles thereto, and a plurality of oblong, axial, rod-like carrying elements 22 arranged at predetermined, equal distances from the tube 18 and thus parallel thereto. The axial carrying elements 22 extend between the end rings 20,21 and are rigidly fixed thereto. The carrying member 55 is provided with two groups 23,24 of connecting rods

or spokes 25, rigidly joined to the tube 18, the spokes 25 of one group 23 being situated inside the end ring 20 are rigidly joined thereto, whereas the spokes 25 of the second group 24 are rigidly joined directly to the outer, axial carrying rods 22, midway along them.

In the embodiment shown in Figure 2 each engagement member 15 is shaped as an oblong, straight engagement arm located parallel to the tube 18 and swivellably journalled to its carrying rod 22 by means of a hinge 26.

The engagement arm 15, made of a metal section with shoe-like cross section, has a curved engagement surface 27 facing away from the tube 18 which, when the central part 9 is inserted into the coil 1, faces the hole wall 5. The ends of each engagement arm 15 are inwardly bevelled for reasons that will be explained below. Each power member 16 (see Figures 3 and 4) is flexibly attached to one spoke 25 of the second group 24 of spokes 25 and to its associated swivelling engagement arm 15 and is arranged, upon connection, to swing the engagement arm 15 from an inactive inner position to an active outer position in which the engagement surface 27 of the engagement arm 15 presses against the inner side or hole wall 5 of the coil 1 with a predetermined smallest force in order to obtain a friction joint between the central part 9 and the coil 1 via all engagement arms 15 and the hole wall 5 to produce a rotatable unit 17 of the central part 9 and coil 1, i. e. without the central part 9 and the coil 1 being able to turn about their centre of rotation in relation to each other. The friction joint is also so strong that the unit 17 can be lifted without the central part 9 and the coil 1 moving axially in relation to each other. In the embodiment shown the power members 16 consist of hydraulic cylinders which, via a common conduit 28, are connected to a hydraulic source 29 consisting of a manually operable hydraulic pump. Since hydraulic cylinders 16 are served by a common conduit 28,

that may be termed annular conduit, they will operate with the same pressure so that the engagement arms 15 will act against the inner side 5 of the coil with the same force since all engagement arms 15 are in engagement with the inner side 5 of the coil, and the engagement operation is complete.

The rotatable unit 17 thus produced is now ready to be carried by an uncoiling device 30 of suitable type.

Figures 5 and 6 show an embodiment of an uncoiling device. In this case the tube 18 also forms the bearing means 14 of the central part, which can therefore be designated bearing tube, the uncoiling device comprising a bearing shaft 31 which is inserted through the hole 19 in the bearing tube 14 to be brought into sliding cooperation with the inner, opposing bearing surface of the bearing tube 14 so that the unit 17 can rotate about the bearing shaft 31 in sliding contact, substantially without clearance. The uncoiling device shown in Figure 5 also includes a stand 32 in the form of a trestle which can be placed on the platform of a vehicle, for instance.

The trestle 32 has a bottom plate 33 and two vertical side walls 34,35, arranged parallel with each other and at predetermined distance from each other in order to define between them a space for receipt of the unit 17.

The distance between the side walls 34,35 is suitably somewhat smaller, e. g. from one or a few centimetres to about 10 cm smaller than the axial dimension (height) of the coil 1. The side walls 34,35 are provided with vertical recesses 36 which are open at the top and have semi-circular support surfaces 37 for receiving said bearing shaft 31 and supporting this and the whole unit 17. The width of the recesses 36 is somewhat larger than the diameter of the bearing shaft 31 to enable the bearing shaft 31 to be lowered through the recesses 36 to rest on the support surfaces 37. It will thus be understood that the bearing shaft 31 is longer than the

axial dimension (height) of the coil 1 and somewhat longer than the distance between the side walls 34,35, measured between their outer sides, so that the bearing shaft 31 has protruding end portions for suitable holders of a lifting device carrying the unit 17 and lowering it to a rotatable position in the trestle 32. The binding strips 3 are cut when the unit 17 and bearing shaft 31 have been lowered into the trestle 32, whereupon the coil 1 will expand axially so that its end sides 7,8 will abut the side walls 34,35 which then form lateral supports for the coil 1. When the object 2 has been uncoiled from the central part 9, a valve in the hydraulic system is opened so that the engagement arms 15 can be swung back to their inactive starting position, e. g. manually. Alternatively the hydraulic cylinders are of the double-acting type so that the engagement arms 15 can be returned by means of hydraulic power.

In an alternative embodiment (not shown) the central part 9 is provided with a bearing shaft to form its said bearing means 14, having the same dimension as the bearing shaft 31 described above. The bearing shaft in accordance with this alternative embodiment is thus rigidly joined to the tube 18 in suitable manner, e. g. a screw or bolt joint, in which case it may be advisable to arrange some form of bearing, e. g. ball or roller bearing at the ends of the bearing shaft and/or at the bottom of the recesses 36 of the trestle 32 in order to facilitate uncoiling of the object 2.

The central part 9 of the tool shown in Figure 7 is similar to that in Figure 1 but also includes a central tube 38 having a hole 39 running through it. The central tube 38 extends through the tube 18, its two end portions being located outside the ends 11,12 thereof. The central tube 38 is detachably fixed to the tube 18, e. g. by means of screw or bolt joint, so that the central tube

38 will form said bearing means 14 of the central part 9.

The tool shown in Figure 7 also comprises two annular end wall elements 40,41, each of which is provided with a hub 42 having a hole, a circular outer ring 43 with larger diameter than the coil 1, and a plurality of spokes 44 joining the outer ring 43 to the hub 42. The end wall elements 40,41 are provided with circular centring elements 45 which are concentric with the centre of the end wall elements 40,41. The centring elements 45 have no function in the present case. However, the advantage is that such end wall elements 40,41 with said central tube 38 can also be used for a parcel delivered to a work site and consisting of a relatively stable sleeve as core and coil of the object, the coil being held together by binding strips passing through the sleeve, whereby the parcel is centred to the end wall elements 40,41 by their centring elements 45 which are in engagement with the inner side of the stable sleeve.

To allow the use of such end wall elements 40, 41 with centring elements 45, therefore, the swivellable engagement arms 15 of the central part 9 are bevelled at their ends on the sides facing the tube 18 as described above, the bevelling being in agreement with the profile of the opposing surface of the centring element 45.

However, the engagement arm 15 shall not be in contact at the time of use so that free movement of the engagement arms 15 from their rest positions is ensured. Said central tube 38 of the tool shown in Figure 7 in this case also forms a connecting element to join the end wall elements 40,41 to each other, which occurs after the coil 1 with binding strips 3 is lowered down around the central part 9 with the engagement arms 15 folded in, in order to rest on the one end wall element 40, and the second end wall element 41 has been placed in position above the coil 1 and the central part 9 as seen in Figure 7. The central tube 38 is thus provided with a locking member comprising a fixed locking flange (not shown) at

one end, which locking flange is brought to abut against the outside of the tube 18 in one end wall element 40 (the lower one in figure 7), and a loose, externally threaded locking sleeve 46 for screwing into the other end of the central tube 38, which is provided with corresponding internal threading in an internally enlarged end part of the hole 39. The locking sleeve 46 is also provided with a locking flange 47 that is brought into contact with the outside of the tube 18 of the second end wall element 41 (the upper one in Figure 7).

Said fixed locking flange (not shown) and the locking sleeve 46 are provided with through-going central holes with the same diameter as that of the opening 39 of the central tube 38, to receive a bearing shaft forming part of a suitable uncoiling device (not shown) which has a stand to support the rotatable unit 17 (see Figure 8) consisting of the coil 1, central part 9, central tube 38 and two end wall elements 40,41.

Figures 9 and 10 show schematically parts of a central part 9 similar to that shown in Figure 1 with the exception of the design of the power members 16. Here these consist of individually manually operated link arm systems, each of which comprises an elongate handle 48 and a link arm 49. The handle 48 is pivotably journalled at its inner end by means of a pivot pin 50 to about the middle of the spoke 25. The handle 48 is movable in a plane coinciding with the spokes 25 when turned about its pivot pin 50. The link arm 49 is pivotably journalled at its inner end by means of a pivot pin 51 to the handle 48, a predetermined distance from the inner, hinged end of the handle 48 and at its outer end is pivotably journalled by means of a pivot pin 52 to the engagement arm 15. Thus, with the aid of the handle 48 and the link arms 49, the engagement arms 15 are caused to move radially outwards towards the inner side 5 of the coil and into the required friction engagement therewith.

After which the link arm systems are locked in their active positions by means of suitable locking mechanisms, including self-clinching, e. g. by the pivot pin 51 being caused to pass a straight line extending through the pivot pins 50,52. The broken line thus represents the inner side 5 of the coil 1 which in this case is circular.

The engagement members 15 of the central parts 9 described above can be folded out individually, i. e. the distance that each engagement member 15 can be folded out is independent of the other engagement member 15.

Figures 11-17 show schematically parts of a tool in accordance with another embodiment of the invention. The tool is designed to be brought into engagement with a coil 1 of the type shown in Figure 1. The tool, intended for repeated use, comprises a central part or hub-forming device 9 for the coil 1, the central part 9 being inserted into the central hole 6 (see Figure 16) of the coil 1 to be activated for cooperation with the inner side 5 of the coil 1. In its non-activated state, therefore, the central part 9 has a cross-sectional dimension that is less than the smallest cross-sectional dimension of the central hole 6 so that the central part 9 can freely, that is to say easily and without difficulty, be inserted into and received by the central hole 6 of the coil 1. From Figures 16 and 17 it can be seen that the coil 1 is deformed so that the central hole 6 has a non-circular cross section. The inner side 5 of the coil 1 is thus not round, i. e. it is non-circular.

The central part 9 comprises an elongate, central, stable body 10 forming a stand with two opposite ends 11,12 and defines a centre line 13 that extends through the ends 11,12. The central part 9 also has a central bearing means 14, a plurality of peripheral engagement members 15, a carrying member 55 and a power member 16. The

bearing means 14 defines an axis of rotation for the tool, which axis of rotation will coincide with the centre line 13 of the central body 10. The bearing means 14 is thus concentric with this centre line 13.

The carrying member 55 is joined to the central, stable body 10 and carries the engagement member 15 which are uniformly distributed around and spaced from the centre line 13. The power member 16 is arranged to actuate the engagement members 15 in direction from the centre line 13 and towards the inner side or inner wall 5 of the coil 1 to bring the engagement members 15 into friction engagement with the inner wall 5 of the coil, producing a unit 17 (see Figure 17), comprising the central part 9 and coil 1, which is rotatable about said axis of rotation coinciding with the centre line 13.

In the embodiment shown in Figures 11-17 the stable body 10 in this case comprises two coaxial cylindrical sleeves 56,57 (see Figure 13) spaced from each other.

Alternatively the sleeves may be joined to form a tube similar to the tube 18 in Figure 1. The sleeves 56,57 have the same inner cylindrical shape and are rigidly fixed together by means of a plurality of axial, rodlike assembly elements 58 (corresponding to the number of engagement members 15) distributed uniformly around the periphery. The stable body 10 thus produced forms a hub and has a hole running through it corresponding to the hole 19 in the embodiment shown in Figure 2. In this case the carrying member 55 is swivellably joined to the body 10 and comprises a plurality of oblong, axial, rodlike carrying elements 59 equally spaced from the central body 10 and thus parallel thereto, and link arms 60,61, that are pivotably journalled at the assembly rods 58 of the central body 10 and the outer carrying rods 59. Each assembly rod 58 and its radially opposite outer carrying rod 59 is swivellably joined by means of two such link

arms 60,61, which four construction elements together form a parallelogram able to assume different angle settings in relation to the central body 10. Each engagement member 15 is shaped as an oblong, straight engagement arm that is located parallel to the central body 10 and is carried by its associated carrying rod 59 via an arrangement of compressible spring members 62 fixed by their ends to the outside of the carrying rods 59 and to the inside of the engagement arm 15. The engagement arm 15, made of a metal section, has a curved engagement surface 63 facing away from the central body 10 which, when the central part 9 is inserted into the coil 1, faces the hole wall 5. The ends of each engagement arm 15 are inwardly bevelled for reasons explained above.

The bearing means 14 is formed by a central tube 64 having a hole 65 running through it, into which a bearing shaft (not shown) of an uncoiling device is inserted to allow the unit 17 to rotate around the bearing shaft as described earlier. The central body 10 is slidable on the central cylinder 64 for axial displacement along this.

The central body 10 is thus fixed against rotation in relation to the central tube since it is to form a part of the rotatable unit 17 with the aid of locking devices, not shown. For this purpose power member 16 is joined to the central body 10 and the central tube 64 to act therebetween. The power member 16 (omitted in Figures 16 and 17) comprises a hydraulic cylinder, the end of which is fixed to one end of the central tube 64 by means of an attachment element 66 and by its piston-rod end is fixed to the sleeve 57 situated furthest away, by means of an attachment element 67. The hydraulic cylinder 16 is connectable to a hydraulic source via a conduit, not shown. Upon activation, the central body 10 and the construction elements 60,61,59,62,63 are displaced along the central tube 64 from an inoperative position as

shown in Figures 11 and 12 to an operative position as shown in Figures 14 and 15, in which the central part 9 is expanded in radial direction by the link arms being swung out to the desired extent, preferably to maximally expanded position when the link arms form right angles with the assembly rods 58. When in inoperative position the central part 9 can easily be inserted into the central hole 6 of the coil 1, as illustrated in Figure 16. When the central part has been expanded to active position, the spring-loaded engagement arms 15 are brought into contact with the inner side 5 so that, if the central hole 6 is non-circular as shown in Figures 16 and 17, the spring members will be compressed to varying degrees depending on the distance of the wall 5 to the centre line 13 at the point when the engagement arm 15 is brought into friction engagement with the coil. Upon expansion of the central part 9 the engagement surfaces 27 of the engagement arms 15 press against the hole wall 5 of the coil with a predetermined minimum spring force so. that a sufficiently strong friction joint is obtained between the central part 9 and the coil 1 via all engagement arms 15 and the hole wall 5 of the operation to achieve a rotatable unit 17 formed by the central part 9 and coil 1, i. e. without the central part 9 and the coil 1 being able to turn about the centre of rotation in relation to each other. The friction joint is also so strong that the unit 17 can be lifted without the central part 9 and the coil 1 moving axially in relation to each other. The rotatable unit 17 thus produced is then ready to be carried by an uncoiling device of suitable type.

The central part described in connection with Figures 11-17 is particularly suitable, but not exclusively, for light coils of an object. Instead of a hydraulic power member 16 a mechanical power member 16 may be used, which is also placed inside the central part 9."Spring device" relates to both mechanical and hydraulic devices with

spring properties, i. e. not only to a compression spring as shown in the drawings which is compressed to different degrees depending on the resistance encountered by respective engagement arm 15 as a result of the force applied by the power member 16 and also where in the ellipse (or other non-circular shape) the engagement arm 15 is located during loading.

Although the tool in accordance with the invention has been described primarily for coils with deformed central openings, the cross section deviating from circular, the tool is equally suitable for use with coreless coils with circular central holes. Furthermore, the tool is equally suitable for use with coils having a circular-cylindrical sleeve forming a core around which the object is coiled.