WO1995011540A1

WO1995011540A1 - Threading device for filiform elements

Info

Publication number: WO1995011540A1
Application number: PCT/EP1994/003428
Authority: WO
Inventors: Albano Carollo
Original assignee: Cae Di Carollo Albano & C. Snc
Priority date: 1993-10-19
Filing date: 1994-10-18
Publication date: 1995-04-27
Also published as: IT1270727B; ITVI930162A0; ITVI930162A1

Abstract

The invention concerns a threading device for threading flexible filiform elements (10, 15) through sheaths or pipes, which includes a bearing structure (2) supporting a power unit (3) and an operating head (4) mechanically connected with each other. Said operating head (4) is provided with dragging means (6) co-operating with said power unit (3) and suitable for carrying out the continuous advancement of said filiform elements (10, 15) inserted between said dragging means (6) and guide means (43, 44) placed before and after said dragging means and suitable for ensuring the alignment of said filiform elements during the dragging.

Description

THREADING DEVICE FOR FILIFORM ELEMENTS.

The invention is a threading device for filiform elements, particularly suitable for threading electric cables through sheaths or pipes laid inside walls, inside ceilings, underground and the like. It is known that the threading of electric cables through laid pipes or sheaths is carried out manually by two persons, one at each end of the sheath or pipe.

In order to carry out the threading, the first operator manually threads a flexible core through the sheath and pushes it manually until it comes out of the opposite end. At this point the second operator couples the ends of the cables to be threaded to the end of the flexible core and after carrying out this operation he informs the first operator, who can now pull the flexible core: this, passing through the sheath again, drags the cables coupled to it.

During this operation it is necessary that the second operator pushes the cables through the sheath, in order to facilitate the threading, while the first operator pulls the flexible core in order to take it out of the sheath.

The operation ends when the first operator, after recovering the flexible core, grasps the ends of the cables.

The drawback of this kind of process lies mainly in the fact that the threading can be carried out only by employing two operators, since, due to the considerable friction between the sheath and the cables, it is impossible to thread the cables by just pulling them together with the flexible core and it is also necessary to push them.

Another inconvenience is represented by the fact that during the threading operation the two operators must be in contact, in order to be able to inform each other when one of them must stop the threading of the flexible core or when, viceversa, he can start recovering it.

It is easy to understand that direct communication can be difficult and that it may be necessary to use two-way radios, especially when the pipes or sheaths through which the cables must be threaded are particularly long or situated in different rooms or on different floors.

It is in order to eliminate the above mentioned drawbacks that the threading device object of the present invention has been carried out, the chief aim of which is it make it possible for a single operator to thread electric cables through sheaths or pipes autonomously, independently of the length and of 2 .

the arrangement of said pipes or said sheaths.

The above mentioned goal has been achieved through the implementation of a device suitable for threading flexible filiform elements through sheaths or pipes, which, according to the main claim, is characterized in that it comprises a bearing structure supporting a power unit and an operating operating head mechanically connected with each other, said operating head being provided with dragging means co-operating with said power unit and suitable for making said flexible filiform elements included among said dragging means advance constantly and being provided also with guide means, positioned before and after said dragging means and suitable for ensuring the alignment of said filiform elements while they are being dragged.

According to a practical execution that is preferred to others, said dragging means consist of at least a couple of rollers, one placed over the other, having coplanar and parallel axes, at least one of which is made rotate by a power unit consisting of a motor connected with a reduction gear of the worm screw-worm wheel type.

Said guide means are made up of a metal ring positioned before said rollers and suitable for facilitating the insertion of the filiform elements between the rollers themselves and of a pipe, positioned after said rollers and coaxial with said metal ring, said pipe being rotatingly connected with the operating head that supports it and being provided with one end shaped so that it can be easily orientated and introduced into the pipe or sheath through which the cables must be threaded. The above mentioned goals will be better highlighted in the description of a practical application among many of the invention in question, illustrated in the attached tables:

-Fig. 1 shows a sectioned rear view of the device object of the invention;

-Fig. 2 shows a sectioned side view of the device object of the invention; -Fig. 3 shows the device in the same configuration shown in Fig. 2, during the advancement of a cable;

-Fig. 4 shows the adjustment element of the dragging unit of the device object of the invention in detail;

-Fig. 5, 6, 7 and 8 show the various phases of the threading of a cable through a sheath or pipe, carried out by means of the device object of the invention; -Fig. 9 shows a variant of the device object of the invention; -Fig. 10 and 1 1 show another variant of the device object of the invention; -Fig. 12 show a further variant of the device object of the invention. As shown in Fig. 1 and Fig. 2, the device object of the invention, indicated as a whole by 1 , includes a bearing structure 2 supporting a power unit, indicated as a whole by 3, and an operating head, indicated as a whole by 4, mechanically connected with each other by means of a supporting flange 5, which belongs to the body 41 of said operating head 4, coupled with the body 31 of said power unit 3 through, for example, screws not represented in the figure.

In a different execution both the body 41 of said operating head 4 and the body 31 of said power unit 3 may belong to a single block making up the bearing structure 2. Said power unit consists of an electric motor 32 that makes a reduction gear 37 rotate, said reduction gear consisting of a worm screw 33 that meshes with a worm wheel 34 making it rotate. Said worm wheel 34 presents a projecting shaft 35, mechanically connected with dragging means, indicated as a whole by 6, -belonging to said operating head 4 and contained inside its body 41. In particular, it is possible to observe in Fig. 1 that said dragging means include a driving roller 61, keyed and fixed to a first pin 62 connected with the projecting shaft 35 of the worm wheel 34 and a contact roller 63, placed over it, keyed and fixed to a second pin 64, where said pins and consequently said rollers keyed to them have the axes, indicated by 65 and 66 respectively, coplanar and parallel to each other and positioned one above the other. The contact roller 63 is driven directly by the shaft 35 projecting from the worm wheel 34, by means of a train of gears 160 consisting of a first gear wheel 161, keyed and fixed to said first pin 62 and of a second gear wheel 163, keyed and fixed to said second pin 64 and meshing with said first wheel 161. In particular, it can be observed that while said first pin 62 has the ends fixed to the body 41 of said operating head 4, said second pin 64 has the ends fixed to an adjustment bracket 8, visible in detail in Fig. 4, which is provided with a slot 81 where a lag screw 42 connected with the body 41 of the operating head 4 is housed. The adjustment bracket 8 can be put in different positions according to its movements in one sense or another, indicated by the arrow 82, and locked in these positions, in such a way as to adjust the distance 67 between the rollers 61 and 63 as a function of the dimensions of the cable 10 or of the cables to be pushed forward, as shown in Fig. 3. In a different execution the adjustment bracket 8 can be replaced by an adjustment lever connected with the contact roller 63 at one end and hinged to the body 41 of the operating head 4 through elastic means that make it possible to automatically adjust the distance between the rollers 61 and 63 according to the thickness of the cable 10. In Fig. 2 it is also possible to observe that before said rollers 61 and 63 there is a guide metal ring 43 fixed to the body 41 of the operating head 4, while after the same rollers there is a conveyance pipe 44, where said metal ring 43 and said conveyance pipe 44 are coaxial to each other, in such a way as to ensure the alignment of the cable during its passage inside the operating head 4.

It can be observed also that said conveyance pipe 44 has the inlet end 144 rotatingly connected with said body 41 of said operating head 4 by means of a bushing 45, so that it can be rotated according to any of the senses of the arrow 46 and that its outlet shaped end 244 can be orientated according to the position of the sheath 9 or of the pipe visible in Fig. 3, through which the cable 10 has to be threaded.

For the use of the device object of the invention, if one, as shown in the Figures 5, 6, 7 and 8, wants to thread one or more electric cables 10 through a pipe 9 laid in a wall 12, one must proceed as described here below. As first thing, as shown in the figures, the bearing structure 2 of the device is anchored to the wall 12 with fastening means which can be, for example, through screws passing through the holes 21 belonging to the bearing structure 2 itself, which are driven into the wall 12. An anchorage system can include, for example, said screws coupling with the fastening elements present in the connector block 13 built in the wall 12 and to which the closing cover of the block itself is applied after the threading has been carried out.

However, it is evident that there can be also other systems to fix the device object of the invention to the wall. After fixing the threading device to the wall 12 the operator, as shown in Fig. 5, inserts the flexible core 15 between the dragging rollers 61 and 63 and connects the engine 32 to the feed cable 16 coming from a feed unit 17 including a rechargeable battery, a cable winder and a device for the reversal of the rotation sense of the engine 32, not represented in the figure, and a switch connected with an external control element, in this case consisting of foot push button 18. Further, said feed unit 17 includes also a control unit for all the functions of the cable threading device.

When the pedal 18 is activated, for example by the operator's foot pressure, as shown in Fig 6, the feed unit 17 feeds the electric motor 32 and makes the advancement rollers rotate; said rollers thread the flexible core 15 through the pipe 9, making it advance in the direction indicated by the arrow 19 until the end 20 of said flexible core 15 comes out of the other end of pipe 9, that is, the end opposite to that into which it has been introduced and to which the threading device 1 is applied. Therefore the operator, as shown in Fig. 7, moves towards said protruding end 20 of the flexible core, bringing along the feed unit 17, and knots it together with the end 22 of the electric cable/cables 10 to be threaded. As shown in Fig. 8, once he has carried out this operation he activates the foot push button 18 again after acting on the device for the reversal of the rotation of the electric motor 32, so that while the threading device 1 starts recovering the flexible core 15 in the direction 23, he pushes the cable 10 inside the pipe 9 in the same direction 23, opposite to the previous direction 19. The control of the electric motor can be a foot push button or any other actuator operated by a radio frequency signal received by the control unit.

When the cable 10 has been threaded through the sheath or pipe, the operator stops the rotation of the engine 32 by releasing his pressure on the pedal 18, unties the knot made with the flexible core 15 and the cable 10 and removes the threading device 1 from the wall 12. The device is now ready to be employed for another threading operation.

Another execution of the device object of the invention is shown in Fig. 9, where it is possible to observe that the contact roller 63 has its second pin 64 keyed to a rod 164 having one end 264 hinged to the body 41 of the operating head 4. The opposite end 364 of said rod 164 is provided with an elastic element 464 bucking against an adjustable pawl 564 screwed on the same body 41 of the same operating head 4. This way any thickening of the cables which should pass between the driving roller 61 and the contact roller 63 during the threading phase would cause the elastic vertical lifting in the direction 163 of the contact roller 63 and of the rod 164 with which it is connected, thus preventing the device from stopping. After the thick part has passed, the return of the elastic element 464 makes the contact roller 63 return to its initial position.

The presence of the pawl 564 makes it possible to properly adjust the position of the contact roller 63 with respect to the driving roller 61 and the elastic reaction force, too.

Another application is represented in Figures 10 and 1 1, where it is possible to observe that the device object of the invention is provided with an anchoring mechanism, indicated as a whole by 100, which makes it possible to fix the threading device inside the connector block 13 built in the wall 12 simply and rapidly.

As shown in Figures 10 and 11, said anchoring mechanism consists of an adjustable rod 101 , slidingly connected with the inside of a guide sleeve, the latter- belonging to the structure of the device. By means of a union pin 103 said adjustable rod 101 is connected with a lever element 104, hinged in intermediate position to the device structure through a hinge pin 105. In particular, it can be noticed that said adjustable rod 101 is provided with a first coupling hook 106, while a second coupling hook 107, analogous to the previous one, is fixed to the structure of the device itself. Further, when the control stick 108 is made rotate around the hinge pin 128, said control stick hinged to the body of the device bucks against an elastic element 109 fixed to an end of the lever 104.

In order to apply the device object of the invention inside the connector block 13, the hooks 106 and 107 are introduced into the block itself, as shown in Fig. 10, and then, by rotating the stick 108 in the clockwise direction 1 10, the elastic end 109 of the lever element 104 is forced by making the latter rotate in the anticlockwise direction 1 1 1. Said first and second hook, 106 and 107 respectively, are provided with pointed elements 206 and 207 that penetrate into the body of the connector block 13 and fix the cable threading device to the wall 12. Depending on the height of the connector block 13, the union pin 103 of the lever element 104 is coupled into one of the holes 120 of the adjustable rod 101 , in such a way as to define the position that is most suitable for obtaining a good adhesion of the hooks inside the connector block itself. Another application is shown in Fig. 12, where it is possible to notice that a spring 344 is externally coupled to the outlet end of the conveyance pipe 44; said spring 344 can be bent in any position, for example in the position represented by the broken line, and therefore can be easily introduced into the sheath present in the connector block, independently of the position of the sheath itself. A further execution is shown in Fig. 9, where it can be observed that the inlet end 144 of the conveyance pipe 44 is rotatingly connected with said body 41 of said operating head 4 by means of a bushing 45 that in this case is a bushing made of insulating material. A couple of contacts 145 protruding towards the inside of the bushing without touching the metal conveyance pipe 44 is positioned radially with respect to said bushing 45 made of insulating material 45 and passes through it. They thus touch the flexible core 15 when this, as shown in the Figures 5, 6, 7 and 8, passes through said conveyance pipe 44. The flexible core 15 is made of plastic insulating material and its end 20 is conductive. As already said, said flexible core is first threaded through the pipe 9 and then it is taken out dragging the electric cables. When its end 20 passes in front of the contacts 145, it causes a short circuit between the contacts and the conveyance pipe 44. The control unit identifies said short circuit, stops the advancement of the flexible core 15 and at the same time sends forth an acoustic signal to inform the operator, who is positioned at the opposite end of the cable threading machine, that the threading is practically concluded. The operator cuts off the cables, so that they protrude of about 50 cm out of the connector block where he is positioned and successively, by means of a command sent forth by radio and received by the control unit itself, cancels the short circuit signal generated by the contacts 145 and activates the driving roller 61 for a few seconds. This makes it possible to further advance the cables inside the pipe for a short length, thus slackening their tension in correspondence with the outlet connector block, so that the operator can easily remove the threading device from the wall. Then the operator manually recovers the remaining part of the cables by pulling them, thus concluding the threading.

According to the above description, the device object of the invention achieves its main goal, that is, makes it possible for a single operator to carry out the threading of cables through sheaths or pipes. It has been shown, in fact, that by means of a control device and an autonomous feed unit provided with switch and motion reversing device it is possible for the same operator to remotely-control the threading device. After the threading of the flexible pipe carried out by the device itself, the core itself can be automatically recovered and at the same time the operator can push the cables manually into the sheath 9.

Obviously, upon implementation the threading device can be modified in order to make construction simpler and more economical. For example, as already explained, it can be provided with more than two advancement rollers, which if necessary can be all powered; the system used to adjust the distances between the rollers can also be different, in such a way as to adapt their position to the thickness of the cable/s to be threaded. In another, different execution the dragging means can also consist of a single dragging roller, which can make the filiform element advance by winding the latter around itself. The device object of the invention, which, as already explained, is particularly suitable for threading electric cables, can be used also for the threading of any filiform element, like, for example, metal wires, compressed air pipes, optical fibres and others. It is understood, however, that any executive variant is considered protected by the present invention.

Claims

O.

1) Threading device for threading flexible filiform elements (10, 15) through sheaths or pipes, characterized in that it includes a bearing structure (2) supporting a power unit (3) and an operating head (4) mechanically connected with each other, said operating head (4) being provided with dragging means (6) co-operating with said power unit (3) and suitable for carrying out the continuous advancement of said filiform elements (10, 15) inserted between said dragging means (6) and guide means (43, 44) placed before and after said dragging means and suitable for ensuring the alignment of said filiform elements during the dragging.

2) Threading device according to claim 1), characterized in that said dragging means (6) consist of at least a couple of rollers (61, 63), one placed over the other, with rotation axes (65, 66) that are coplanar with and parallel to each other, said couple of rollers including a driving roller (61) keyed and fixed to a first pin (62) mechanically connected with the body (41) of said operating head (4) and co-operating with said power unit (3), and a contact roller (63) keyed and fixed to a second pin (64) rotatingly supported by adjustment means (8) suitable for varying the height of said contact roller (63) with respect to said driving roller (61 ), said pins (62, 64) being kinematically connected with each other by means of a train of gears ( 160).

3) Threading device according to claim 2), characterized in that said train of gears ( 160) includes a first gear wheel (161 ) keyed and fixed to said first pin (62) meshing with a second gear wheel (163) keyed and fixed to said second pin (64). 4) Threading device according to claim 2), characterized in that said adjustment means are at least a substantially U-shaped adjustment rod (8) supporting both ends of said second pin (64) of said contact roller (63) and provided with union means consisting of a lag screw (42) fixed to said body (41) of said operating head (4) and passing through a slot (81) made in the body of the adjustment rod (8).

5) Threading device according to claim 1 ), characterized in that said guide means positioned before and after said dragging means (6) consist of a feed metal ring (43) placed before said dragging means and fixed to the body (41) of the operating head (4) and of a conveyance pipe (44) rotatingly connected with the same body (41 ) of the same operating head (4) by means of a bushing (45) and positioned after said dragging means (6), said feed metal ring (43) and said conveyance pipe (44) being coaxial to each other.

6) Threading device according to claim 5), characterized in that said conveyance pipe (44) has a shaped end (244) opposite the end (144) fixed to the body (41) of said operating head (4), said shaped end (244) being suitable to be inserted into the end of the pipe or of the sheath (9).

7) Threading device according to claim 5), characterized in that said conveyance pipe (44) has a spiral spring (344) in correspondence with its outlet end. 8) Threading device according to claim 1), characterized in that said at least one power unit (3) includes an electric motor (32), electrically connected with a feed unit (17) and a speed reducer (37).

9) Threading device according to claim 8), characterized in that said speed reducer is a reducer of the worm screw (33)-worm wheel (34) type. 10) Threading device according to claim 8), characterized in that said feed unit (17) includes at least a feeding battery, electrically connected with said electric motor (32) by means of a feed cable (16) provided with cable winder, a device for the reversal of the motion of the electric motor (32) itself, and a switch electrically connected with the electric motor (32), said switch being provided with control means (18).

1 1) Threading device according to claim 10), characterized in that said control means consist of a foot push button (18).

12) Threading device according to claim 10), characterized in that said control means consist of a radio control. 13) Threading device according to claim 2), characterized in that said second pin (64) of said contact roller (63) is mechanically connected with the body (41) of said operating head (4), being rotatingly connected with a rod (164) having one end (264) hinged to said body (41) and the opposite end (364) provided with an elastic element (464) bucking against an adjustable pawl (564) screwed to the body (41) itself.

14) Threading device according to claim 1), characterized in that it is provided with means for the anchorage to the connector block (13) applied to the wall (12), said anchoring means including a couple of hooks (106, 107) mechanically connected with the body of said device, the position of which can be varied with control means (108, 104), said hooks (106, 107) being suitable for being introduced into said connector block (13) and being provided with pointed elements (206, 207) suitable for carrying out the outlet inside said connector block (13).

15) Threading device according to claim 14), characterized in that said couple of hooks includes a first hook (107) fixed to the body of said cable threading device and a moving hook (106) applied to an adjustable rod (101) sliding inside a guide sleeve (102) belonging to the body of the device itself.

16) Threading device according to claim 15), characterized in that said adjustable rod (101) is connected with the end of a lever element (104) by means of a union pin (103), said lever element (104) being hinged in intermediate position to the body of said device and having at the opposite end an elastic element (109) bucking against a rotating rod (108) hinged to the body of the same device by means of a pin (128).

17) Threading device according to claim 5), characterized in that said bushing (45) is made of insulating material and receives a couple of electric contacts (145) radially passing through the bushing (45) itself, said contacts (145) protruding towards the inside of the bushing itself.

18) Threading device according to claim 10), characterized in that said feed unit (17) includes an electronic unit controlling the functions of said device, said control electronic unit being suitable for operating said device according to radio frequency signals sent forth by a transmitter.