SE539401C2

SE539401C2 - Threading device for threading a line or a cable

Info

Publication number: SE539401C2
Application number: SE1551504A
Authority: SE
Inventors: Carlson Eric
Original assignee: Hook & Moor Ab
Priority date: 2015-11-20
Filing date: 2015-11-20
Publication date: 2017-09-12
Also published as: SE1551504A1; WO2017086860A1

Description

THREADING DEVICE FOR THREADING A LINE OR A CABLE TECHNICAL FIELD The present invention relates to a threading device for threading a line or cable repeatedly past cross members of a cable ladder. The threading device can also be used when threading a mooring line of a boat through a mooring ring. By the use of the threading device, a cable can be pulled passed the cross beams of the cable ladder in an easy way with the user standing on the floor beneath the cable ladder. In this way, a cable can be installed on the cable ladder without having to thread the cable to pass each cross beam. One advantage of the threading device is that the installation operation can be performed from underneath the cable ladder, without having to reach the upper side of the cable ladder.

BACKGROUND ART When installing a cable in a larger building or in a factory, several cables are normally routed in specific cable ducts in order to provide a well-arranged cable installation that is easy to maintain. Separate cables are often installed side by side on cable ladders or cable trays. Some cable trays are closed and some cable ladders or cable trays are open. Different cables conducting different signals and different voltages are often separated some or are installed on separate cable ladders. A cable ladder comprises two longitudinal bars or beams interconnected by cross members or rungs arranged at a specific distance, which may be e.g. between 20 - 50 cm depending on the size of the cable ladder.

One problem when installing a cable on a cable ladder is that the cable ladder is often positioned high, close to the ceiling or at least above head height of humans. When installing a cable, the electrician must stand on a ladder or a platform in order to be able to reach the upper side of the cable ladder, where the cable is installed. Cables may be installed one by one but normally, a cable bundle comprising several cables is pulled over the cable ladder by the use of a pulling line. However, the pulling line must first be positioned on the cable ladder, which is time consuming and difficult due to the high position of the cable ladder. In order to reach the upper side of the cable ladder, a platform or a ladder must be used. The platform or ladder may be unstable and must be moved constantly in order to reach into the complete cable ladder. The installation of several cables at the same time is normally performed in new installations.

When a single cable is to be installed at a later stage, e.g. in a building that is being used, it is often unpractical to use a platform. In such a case, a ladder can be used. A ladder may however be unstable and it has to be moved constantly in order to reach the complete cable ladder. Often the cable ladder is concealed by a dropped ceiling which consists of a gridwork of metal channels holding ceiling tiles or panels. The panels are removed in order to reach the cable ladder. However, the installation of a cable is difficult since the cable must be threaded past both the cross members of the cable ladder and the grid work of the ceiling. This is often the case when a new communication line or a fibre is to be installed e.g. in an office building. Different threading devices have been proposed, adapted to thread a wire or line through a single ring shaped member. These threading devices are mainly adapted to simplify the mooring of a boat to a buoy or the like, where a single threading action is enough.

US 4,560,098 relates to a device suitable for threading a line through a ring member or the like. This solution is adapted for a single threading action in a predetermined direction. DE 10 2006 029 810 A1 discloses a device for threading a line through a ring member or the like. This device is adapted to a single threading action and the device must be moved in two different directions in order to thread a line through a ring member. GB 287,407 and GB 442,857 show further examples of threading devices. Both are rather complicated and require a specific looped line end to function. WO 2009124934 A1 shows a threading device adapted for a single threading action of a line through a mooring ring.

There is thus a need for an improved threading device adapted to simplify the installation of a cable on a cable ladder.

DISCLOSURE OF INVENTION An object of the invention is therefore to provide a threading device for repeatedly threading a cable past cross members of a cable ladder.

With a threading device for threading a line or cable past a cross member of a cable ladder, comprising a housing, a rotatable arc-shaped element suspended in the body and having an opening, and a line or cable holding means arranged to slide on the arc-shaped element, where the arc-shaped element is adapted to assume a first position with the opening in a first direction and a second position with the opening in a second direction, and further comprising transfer means adapted to transfer a movement of a handle to an outer surface of the arc-shaped element in order to rotate the arc-shaped element between the first position and the second position, the object of the invention is achieved in that the threading device further comprises a resilient means adapted to return the arc-shaped element to its starting position, and that the resilient means can be set in a first state adapted to return the arc-shaped element to the first position and in a second state adapted to return the arc-shaped element to the second position.

By this first embodiment of the threading device according to the invention, a threading device is obtained which is adapted for a repeated threading of a cable over a plurality of cross members of a cable ladder. The arc-shaped element is returned to its starting position by a resilient means, which allows a user to repeatedly perform a plurality of threading actions, e.g. when threading a line or cable past a plurality of cross members of a cable ladder. This allows for a time efficient threading of a line or cable, without the need to use a ladder or platform in order to reach above the cable ladder. The resilient means can be set in a first state or in a second state, allowing for a pulling threading action or a pushing threading action.

In an advantageous further development of the threading device according to the invention, the resilient means can be set in a third state, in which the arc-shaped element is not returned to its starting position. In this way, the threading device can be used for a single threading action, e.g. for the mooring of a boat at a mooring ring. It is also possible to use a locking means to lock the arc-shaped element in a fixed position, preferably in the first position. In this way, the threading device can be used e.g. as a conventional boat hook.

In an advantageous further development of the threading device according to the invention, the outer surface of the arc-shaped element is provided with a plurality of teeth. The teeth are adapted to interact with corresponding teeth of a transfer means, which is used to rotate the arc-shaped element from the first position to the second position or from the second position to the first position.

In an advantageous further development of the threading device according to the invention, the transfer means comprises several balls and a pusher arranged in an endless ball channel. This gives the threading device a smooth operation and provides low friction for the movement of the arc-shaped element. The use of a pusher to move the balls in the ball channel allows for an operation in both directions. The cable is attached to the cable holding means and the cable is then forwarded past the cross members of the cable ladder from below. When several cables are to be installed at the same time, it is possible to first thread a pilot pulling line over the cable ladder which is attached to the cables. The cables are then pulled in position by the pulling line. The transfer means may also be a chain, a toothed drive belt or a roller chain.

In an advantageous further development of the threading device according to the invention, the pusher is attached to a handle, such that the arc-shaped element is moved between the first position and the second position by pulling or pushing the handle. By mounting the pusher to a handle, the length of the threading device can be adapted to the height of the cable ladder. The handle is preferably telescopic and extendable.

In an advantageous further development of the threading device according to the invention, the resilient means is an elastic band attached to the handle and to at least one slider, where the elastic band runs over at least one pulley. By using an elastic band and at least one pulley changing the direction of the elastic band, a relatively uniform force can be obtained from the elastic band over the complete rotational movement of the arc-shaped element.

In another embodiment of the threading device according to the invention, the pusher of the threading device is a toothed wheel driven by a motor. The motor may be controlled by switches operated by the user. The motor can drive the arc-shaped element from one position to the other position and a resilient means can return the arc-shaped element to its starting position. It is also possible that the motor preloads the resilient means and that the arc-shaped element is returned to the starting position by releasing the resilient means by a switch. It is also possible that the motor drives the arc-shaped element from one position to the other position and that the motor also returns the arc-shaped element to its starting position.

BRIEF DESCRIPTION OF DRAWINGS The invention will be described in greater detail in the following, with reference to the embodiments that are shown in the attached drawings, in which Fig. 1 shows a first embodiment of a threading device according to the invention with the arc-shaped element in a first position, Fig. 2 shows the threading device according to the invention with the arc-shaped element in a second position, Fig. 3a shows a side cut view of a threading device according to the invention with the arc-shaped element in a first position, Fig. 3b shows a cut view from above of a threading device according to the invention with the arc-shaped element in a first position, Fig. 4 shows a cut view of a second embodiment of a threading device according to the invention, Fig. 5 shows a schematic view of the use of a threading device when installing a cable on a cable ladder, and Figs. 6a - 6f show different steps of a threading action when installing a cable on a cable ladder.

MODES FOR CARRYING OUT THE INVENTION The embodiments of the invention with further developments described in the following are to be regarded only as examples and are in no way to limit the scope of the protection provided by the patent claims.

Figs. 1 to 3 show a first embodiment of the inventive threading device. The threading device 1 comprises a housing 2 having outer side walls. The side walls are parallel and are positioned apart with a predefined distance. The housing 2 comprises a head 16 and an elongated body 17. In the head, a circular arc-shaped element 3 is arranged. The arc-shaped element 3 is provided with teeth 6 on the outer surface 14. The toothed arc-shaped element extends out of the body and is part-circular with an opening 4 having an opening angle preferably extending over a range between 60 and 120 degrees. The diameter of the opening in the arc-shaped element is determined on the size of the cross beams of the cable ladder, and is preferably larger than 6 cm.

The arc-shaped element is in the shown example provided with a groove 22 which will slide in correspondingly shaped protrusions in the head. In this way, the arc-shaped element can be held in position in the head and will be able to rotate in the head. The arc-shaped element will rotate with the opening facing inwards towards the head, and the rotation of the arc-shaped element is approximately 270 degrees. The arc-shaped element is further provided with a slit 23. A cable holding means 5 extends through the slit 23 and will slide in the slit when the arc-shaped element rotates. The length of the slit preferably corresponds to the amount of rotation of the arc-shaped element, such that the cable holding means can act as end stops of the rotation. The arc-shaped element 3 is adapted to assume a first position 25 with the opening in a first direction and a second position 26 with the opening in a second direction.

The outer surface of the arc-shaped element is in the shown example provided with teeth 6 adapted to interact with a transfer means adapted to rotate the arc-shaped element from the first position to the second position or from the second position to the first position. The transfer means may e.g. consist of balls, a chain, a toothed drive belt or a roller chain. It is however important that the transfer means has a relatively long extension such that it can interact with the arc-shaped element through the complete rotation of the arc-shaped element. In the shown example, the angular opening of the arc-shaped element is approximately 90 degrees and the transfer means extend over approximately 120 degrees. In this way, the transfer means will always be in contact with part of the arc-shaped element during a rotation of the arc-shaped element from one position to the other position.

In the shown example, balls are used as the transfer means. Inside the housing 2, an endless ball channel 9 is arranged. In the endless ball channel, a plurality of balls 7 and a pusher 8 are arranged. The pusher is adapted to push the balls in a forward or backward direction in the ball channel, depending on the desired rotational direction of the arc-shaped element. The end surfaces of the pusher may be provided with spherical surfaces adjacent the balls such that an end surface resembles part of a ball. This allows the pusher to push the balls in a smooth and reliable way. The pusher 8 extends out of the ball channel with an attachment section 18 adapted to be attached to a handle 10 with e.g. screws. The attachment section runs in a groove in the ball channel and can move in a longitudinal direction along the elongated body 17. The pusher can move between a forward end position 20 and a rearward end position 21. The distance between the forward end position 20 and the rearward end position 21 preferably corresponds to the amount of rotation of the arc-shaped element, such that the pusher can act as an end stop for the rotation of the arc-shaped element. The length of the body is preferably matched to the distance between the forward end position 20 and the rearward end position 21.

The ball channel is filled with balls apart from the pusher. The toothed outer surface of the arc-shaped element 3 extends into part of the ball channel in the head of the threading device. When the pusher is moved in one direction, the pusher will push the balls in the same direction. The balls will glide or rotate and push each other in the same direction, and the toothed outer surface of the arc-shaped element will rotate in the desired direction, moving the arc-shaped element from one position to the other position.

The attachment section 24 of the pusher 8 is fixedly attached to a handle 10, e.g. by screws or rivets. In this way, the pusher can be moved by pulling or pushing the handle. In the example shown in Fig. 1, the pusher is in the forward end position 20, i.e. in the inner position, and the arc-shaped element 3 is in the first position 25. In this position, the inner end of the handle 10 is also at the end position 20. By pulling the handle, the pusher and the handle will move away from the head of the threading device, towards the rearward end position 21. At the same time, the balls will rotate the arc-shaped element counter-clockwise from the first position 25 to the second position 26, as shown in Fig. 2.

By pushing the handle from this extended position, the pusher and the handle will return to the forward end position 20 and the arc-shaped element will return to the first position 25, i.e. the starting position, with a clockwise rotation.

The shown threading device is provided with a resilient means 11 which is adapted to return the arc-shaped element to the starting position. In the shown example, the resilient means is an elastic band which runs over a front pulley 12 and a rear pulley 13. One end of the elastic band is attached to a first slider 18 and the other end of the elastic band is attached to a second slider 19. In the shown example, the first slider 18 is positioned in the forward end position 20 and is attached to the handle 10, close to the position of the attachment section 24. The second slider 19 is positioned at the rearward end position 21 and bears at the body. In this example, the elastic band will run from the second slider 19, over the rear pulley 13, over the front pulley 12 to the first slider 18 which is attached to the handle.

By pulling the handle, the elastic band is extended at the same time as the arc-shaped element is moved from the first position to the second position. When the handle is fully extended, such that the inner end of the handle, the pusher and the first slider is in the rearward end position, the elastic band has been extended by approximately twice its length. This position is shown with dashed lines in Fig. 3b.

When a cable is threaded over a cross member of a cable ladder, the inner surface of the arc-shaped element will bear on a cross beam of a cable ladder. In this way, the inner surface will slide and rotate on the cross beam, which at the same time will provide the reaction force to the pulling force of the handle when the handle is pulled. In this way, the threading device can be operated with one hand. When the arc-shaped element is in the second position and the arc-shaped element is released from the cross beam, the elastic band will pull the handle back to the starting position, i.e. to the inner position, and the arc-shaped element will at the same time return to the first position, i.e. to the starting position. The cable has now passed the cross member and the threading device is ready to thread the cable passed another cross member.

The second slider 19 is in the shown example positioned at the rearward end position 21. In this way, the pusher can be pulled from the forward end position 20 to the rearward end position 21 and is returned by the elastic band to the forward end position 20. The second slider 19 may also be attached to the inner end of the handle when the inner end of the handle and the pusher are positioned at the rearward end position, with the arc-shaped element in the second position 26. In this case, the first slider will be positioned at the forward end position 20. The elastic band will in this case run from the second slider 19, over the rear pulley 13, over the front pulley 12 to the first slider 18. In this way, the starting position of the pusher will be the rearward end position 21. By pushing the handle inwards, the pusher will move from the rearward end position to the forward end position and the arc-shaped element will move from the second position to the first position.

When threading a cable over a cross member of a cable ladder, the inner surface of the arc-shaped element will bear against the cross member of the cable ladder, such that the handle can be operated by one hand. When the arc-shaped element is released from the cross member, the pusher and the handle will be pulled back to the starting position by the elastic band and the arc-shaped element will be returned to the starting position, which in this case is the second position.

The threading device is preferably provided with a pin or the like that will allow a user to select which slider that is to be attached to the handle. In this way, the user can decide which type of action that the threading device should be operated with. By attaching the first slider 18 to the handle, a pulling action is obtained, by attaching the second slider 19 to the handle, a pushing action is obtained. Some users may prefer a pulling action and some users may prefer a pushing action.

The resilient means can also be set in a third state in which the arc-shaped element is not returned to its starting position. This may be done by releasing the resilient means from the handle, e.g. by leaving both the first slider and the second slider unattached to the handle. In this way, the threading device can be used for a single threading action, e.g. for the mooring of a boat at a mooring ring. It is also possible to use a locking means, e.g. a releasable button, a pin or the like, to lock the arc-shaped element in a fixed position, preferably in the first position. The locking means may act directly on the arc-shaped element, directly on the handle or may block the transfer means. In this way, the threading device can be used e.g. as a conventional boat hook.

It is also possible to use a coil spring as the resilient means. A coil spring may be arranged inside the handle, e.g. between the rear part of the body and a position at the rear end of an elongated handle. Depending on where in the handle the rear end of the coil spring is attached, a pulling force or a pushing force can be provided by the coil spring. When a coil spring is used, it may be preferred to elongate the body somewhat in order to provide a relatively uniform spring force from the coil spring.

The housing is preferably made from a reinforced plastic, such as a fibre reinforced polyamide. The arc-shaped element is preferably manufactured from a strong and rigid material. It can be cast or machined from a metal or may also be made from a reinforced plastic, such as a fibre reinforced polyamide.

In a second embodiment of the threading device according to the invention, shown in Fig. 4, the pusher of the threading device is a toothed wheel 31 driven by a motor 30. The toothed wheel is positioned in the endless ball channel, which in this example is much shorter than in the embodiment described above. The toothed wheel 31 will be rotated by the motor such that the balls are moved in a forward or rearward direction. The balls will rotate the arc-shaped element from one position to another position. The motor is preferably positioned perpendicular to the toothed wheel in order to fit in a handle, which means that the toothed wheel preferably is driven through a worm drive comprising a worm and a worm gear. In this way, the rotational speed of the motor will also be reduced and the torque of the motor will be increased.

The motor may be controlled by switches 33 operated by the user. The motor can drive the arc-shaped element from the first position to the second position by e.g. activating a forward switch, and drive the arc-shaped element from the second position to the first position by activating a backward switch. It is also possible that the motor drives the arc- shaped element from the first position to the second position and that a resilient means returns the arc-shaped element to its starting position. The resilient means may in this case be a clock spring arranged at the toothed wheel. The motor may also preload the resilient means such that the resilient means will drive the arc-shaped element from the first position to the second position by releasing a catch, and the motor will then return the arc-shaped element to its starting position. The motor is preferably powered by rechargeable batteries 32, which may be built in or may be exchangeable.

Fig. 5 and 6a - 6f demonstrates the installation of a cable on a cable ladder by using the inventive threading device. The cable ladder 40 comprises a plurality of cross members or rungs 41. Since the cable should be installed on top of the cable ladder, the cable must be threaded over each cross member. The end of the cable is attached to the cable holding means in a secure way. The threading device is then placed at the first cross member with the inner surface of the arc-shaped element resting on the cross member, with the arc-shaped element in the first position, as shown in Fig. 6a and 6f. The threading device is pulled by the handle which causes the arc-shaped element to rotate from the first position to the second position, see Figs 6b - 6d. By pulling the handle, the handle extends outwards and extends the resilient member. The end of the cable will now be on the other side of the cross member and the threading device can be released from the cross member and can be moved to the next cross member. At the same time, the arc-shaped element is returned to the first position by the resilient means, and the handle is returned to its inner position, as seen in Fig. 6e. The threading device is now ready to thread the cable over the next cross member. At the next cross member, the inner surface of the arc-shaped element is again placed bearing on the cross member and the handle is pulled. The end of the cable will now pass the cross member and the process can be repeated until the cable end has passed all cross members.

The invention is not to be regarded as being limited to the embodiments described above, a number of additional variants and modifications being possible within the scope of the subsequent patent claims. It is e.g. possible to integrate the threading device in different types of handles, and the rotatable, arc-shaped element can be suspended in the body of the threading device in a number of ways encompassed by the claims.

REFERENCE SIGNS 1: Threading device 2: Housing 3: Arc-shaped element 4: Opening 5: Cable holding means 6: Tooth 7: Ball 8: Pusher 9: Ball channel 10: Handle 11: Resilient means 12: Front pulley 13: Rear pulley 14: Outer surface 15: Inner surface 16: Head 17: Body 18: First slider 19: Second slider 20: Forward end position 21: Rearward end position 22: Groove 23: Slit 24: Attachment section 25: First position 26: Second position 30: Motor 31: Toothed wheel 32: Battery 33: Switch 40: Cable ladder 41: Cross member

Claims

1. Threading device (1) for threading a line or cable past a cross member of a cable ladder, comprising a housing (2), a rotatable arc-shaped element (3) suspended in the body and having an opening (4), and a line or cable holding means (5) arranged to slide on the arc-shaped element, where the arc-shaped element is adapted to assume a first position (25) with the opening in a first direction and a second position (26) with the opening in a second direction, and further comprising transfer means (7) adapted to transfer a movement of a handle (10) to an outer surface (14) of the arc-shaped element (3) in order to rotate the arc-shaped element between the first position (25) and the second position (26), characterized in that the threading device further comprises a resilient means (11) adapted to return the arc-shaped element (3) to its starting position, and that the resilient means (11) can be set in a first state adapted to return the arc-shaped element (3) to the first position (25) and in a second state adapted to return the arc-shaped element (3) to the second position (26).

2. Threading device according to claim 1, characterized in that the resilient means (11) is attached to the handle (10).

3. Threading device according to claim 1 or 2, characterized in that the resilient means (11) can be set in a third state in which the arc-shaped element (3) is not returned to its starting position.

4. Threading device according to any of claims 1 to 3, characterized in that the arc-shaped element (3) can be locked in the first position (25) by a locking means.

5. Threading device according to any of claims 1 to 4, characterized in that the outer surface (14) of the arc-shaped element (3) comprises a plurality of teeth (6), adapted to cooperate with the transfer means (7).

6. Threading device according to claim 5, characterized in that the transfer means (7) comprises a plurality of balls (7) and a pusher (8) arranged in an endless ball channel (9), where a plurality of balls cooperate with the teeth (6) of the arc-shaped element (3), and where the pusher (8) is adapted to push the balls (7) in an either forward or rearward direction in the ball channel (9).

7. Threading device according to claim 6, characterized in that the pusher (8) is attached to the handle (10), such that the arc-shaped element (3) is moved between the first position (25) and the second position (26) by pulling or pushing the handle (10).

8. Threading device according to any of claims 1 to 7, characterized in that the resilient means (11) is a coil spring.

9. Threading device according to any of claims 1 to 7, characterized in that the resilient means (11) is an elastic band attached to the handle (10) and to at least one slider (18, 19), where the elastic band runs over at least one pulley (12,13).

10. Threading device according to claim 6 or 7, characterized in that the pusher (8) is a toothed wheel (31) drivingly engaged with a motor (30).

11. .Threading device according to claim 10, characterized in that the motor (30) drives the arc-shaped element (3) from one position to the other position and that a resilient means (11) returns the arc-shaped element (3) to its starting position.

12. Threading device according to claim 10, characterized in that the motor (30) drives the arc-shaped element (3) from one position to the other position and that the motor also returns the arc-shaped element (3) to its starting position.

13. Threading device according to any of claims 10 to 12, characterized in that the resilient means (11) is a clock spring.