AU2008264210B2

AU2008264210B2 - Cable Bulbing Apparatus and Method for Forming Bulbs in a Cable Bolt

Info

Publication number: AU2008264210B2
Application number: AU2008264210A
Authority: AU
Inventors: Anthony Paul Steains
Original assignee: FCI Holdings Delaware Inc
Current assignee: FCI Holdings Delaware Inc
Priority date: 2005-02-17
Filing date: 2008-12-24
Publication date: 2016-05-05
Anticipated expiration: 2025-02-17
Also published as: AU2008264210A1

Abstract

Abstract A cable bulbing apparatus (50, 100) having a frame (1, 101) and securing means (3, 5 103) for holding at least a portion of a cable bolt (4, 104) with respect to the frame (1, 101). The apparatus also includes a bulbing assembly (5, 105) which is releasably engagable with the cable bolt (4, 104). The assembly (5, 105) is movable relative to the frame (1, 101) to enable one or more bulbs to be formed along the cable bolt length.

Description

- 1 CABLE BULBING APPARATUS AND METHOD FOR FORMING BULBS IN A CABLE BOLT FIELD OF THE INVENTION 5 The present invention relates to cable bulbing apparatus and a method of forming bulbs in a cable bolt. The invention has been developed primarily for forming bulbs in rock anchor cable bolts and will be described herein with reference to that application. However, it should be understood that the invention is not limited to that particular field of use and may be suitable for other applications. 10 BACKGROUND OF THE INVENTION Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. 15 Known apparatus for forming bulbs in cable bolts include those described in Australian Patent Nos. 723113 ('113), 640906 ('906) and 770594 ('594). '113 describes an apparatus which includes two clamp means, one of the clamp means including a one way clamp and a displacement means for displacing the 20 clamping means towards one another to form the bulb. By comparison, '906 describes an apparatus including a pair of clamp means with each clamp including a pair of plates for clamping a cable. The apparatus also includes a clamp displacement means arranged to displace the clamp means towards 25 one another to form a bulb in a cable and a cable displacement means for displacing the cable longitudinally after a bulb has been formed. Alternatively, '594 describes an apparatus and method for manufacturing a multi-strand rock bolt including feed means for supplying a multi-strand cable from a 30 rotatable supply reel, a means for forming the cable with bulbs at spaced intervals and -2 a means for determining the position of the cable to stop operation of the feed means to enable a further bulb to be formed. SUMMARY OF THE INVENTION 5 According to a first aspect of the invention there is provided an apparatus for forming one or more bulbs in a cable, the apparatus comprising: a frame; securing means that is releaseably engageable with the cable; and a bulbing assembly comprising a base, and first and second clamp sets mounted to the base, the clamp sets of the bulbing assembly being releasably engagable with the cable and relative 10 movement of said clamp sets forms a bulb in said cable; the bulbing assembly being movable relative to the frame independently of the relative movement of the clamp sets; and the bulbing assembly being operative to form one or more bulbs in the cable by relative movement of the clamp sets and to reposition the cable relative to the frame to advance the cable through the apparatus by movement of the bulbing assembly 15 relative to said frame independently of the relative movement of the clamp sets. In one form, the bulbing assembly is slidably mounted to the frame. In one form, the first and second clamp sets each include a pair of hydraulically 20 operated mutually opposed jaws for clamping the cable bolt. In one form, the first clamp set is fixedly mounted to the base and the second clamp set is movably mounted to the base. 25 The bulbing assembly may include an actuator for providing the relative movement between the first and second clamp sets, the actuator being fixedly mounted to the base and in moving engagement with the second clamping means. In one embodiment, the actuator is hydraulically or electrically powered. 30 In one form, the securing means is one or more cable bolt locking clamps.

-3 In particular embodiments, a second actuator is provided to cause movement of the bulbing assembly relative to the frame. In one form, the second actuator is hydraulically actuated. 5 In one form, the frame includes a pair of parallel racks. The bulbing assembly may include a set of pinions in gearing engagement with the parallel racks for enabling the bulbing assembly to move along the frame under operation of the second actuator. 10 In a particular embodiment, the set of pinions includes a pair of driven front pinions and a complementary pair of rear idler pinions. In one form, the apparatus includes one or more proximity sensors for 15 measuring the radial displacement of the bulb formed in the cable bolt. This radial displacement may also be set by control of the maximum oil pressure being applied to the actuator or by a timer controlling the length of time that oil pressure is applied to the actuator. 20 In one form, the apparatus includes an encoder for controlling the movement of the bulbing assembly along the cable. According to a second aspect of the invention there is provided a method for forming bulbs in a cable, the method comprising the steps of: 25 positioning a cable on a frame; engaging a bulbing assembly at a first location on the cable, the bulbing assembly comprising first and second clamp sets configured to move relative to one another to form a bulb in the cable; forming a bulb in the cable at the first location by moving the clamp sets 30 relative to one another; -4 repositioning the bulbing assembly relative to the frame whilst at least one of the first and second clamp sets of the bulbing assembly is engaged with the cable so that the cable is caused to advance; reengaging the bulbing assembly at a second location along the cable; and 5 forming a second bulb in the cable at the second location by again moving the clamp sets relative to one another. In one form, the bulbing assembly is slidably mounted to the frame to allow the assembly to move from the first location to the second location on the cable bolt. 10 In one form, one or more proximity sensors send a signal to stop the bulbing process when the strands of the cable bolt reach a desired radial displacement. In a particular arrangement, the bulbing assembly disengages the cable bolt 15 after the first bulb is formed and moves along the cable until an encoder sends a signal to stop at the second bulbing location and the bulbing process is repeated. In one embodiment, after forming the bulb in the first location on the cable bolt, the method comprises the additional steps of: 20 releasing the cable bolt relative to the frame; repositioning the bulbing assembly from a first position relative to the frame to a second position relative to the frame whilst the bulbing assembly is engaged with the cable bolt so that the cable bolt is caused to move relative to said frame; and securing the cable bolt relative to the frame. 25 The cable bolt may be supplied to the bulbing assembly by a cable reel or a pick and place style system. In one form, the cable is removed from the bulbing assembly by pick and place 30 style system.

-5 In another aspect, the invention provides a method for forming one or more bulbs in a cable, said method comprising the steps of: (a) positioning a cable on a frame; (b) positioning a bulbing assembly at a first position on said frame, the 5 bulbing assembly comprising first and second clamp sets configured to move relative to one another to form a bulb in the cable; (c) engaging the bulbing assembly at a first location on said cable; (d) forming the bulb in said cable at said first location; (e) repositioning the bulbing assembly to a second position on said 10 frame whilst at least one of the first and second clamp sets of the bulbing assembly is engaged with the cable so that the cable is caused to move relative to the frame; (f) releasing the bulbing assembly from the cable; (g) securing the cable relative to the frame; and 15 (h) repositioning the bulbing assembly towards the first position on the frame. In one form, the method further comprises the step of: (i) engaging said bulbing assembly at a second location on said cable 20 bolt after the bulbing assembly has been repositioned towards the first location. In one form, the method further comprises the step of: (j) forming a second bulb in said cable at said second location. 25 In one form, the method further comprises the steps of: (k) repeating steps (e) to (h); and (1) engaging said bulbing assembly at a third location on said cable bolt. BRIEF DESCRIPTION OF THE DRAWINGS 30 Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: -6 Figure 1 is a plan view of a cable bulbing machine in accordance with the present invention, showing a cable prior to bulbing; Figure 2 is a plan view of the cable bulbing machine, showing a cable after a bulb has been formed: 5 Figure 3 is a plan view of the cable bulbing machine of an alternative embodiment, showing the cable after a bulb has been formed, where the bulbing assembly is in a first position along the frame; Figure 4 is a plan view of the machine in Figure 3, with the bulbing assembly, bulb and cable displaced longitudinally to a second position relative to the frame; and 10 Figure 5 is a plan view of the machine in Figure 3 with the bulbing assembly returned to the first position after displacing the cable. DETAILED DESCRIPTION OF THE INVENTION Referring to Figures 1 and 2, the cable bulbing apparatus 50 for use in forming 15 bulbs in cable for use in cable bolts. The apparatus 50 includes a frame 1 having a pair of parallel racks 2. A securing means in the form of a cable locking clamp 3 is mounted to one end of the frame for holding at least a portion of a cable 4 in place during the bulbing process. The cable locking clamp may also be utilised to crimp fittings such as "fish hooks" or steel sleeves on to the end of the cable bolt. 20 The apparatus also includes a bulbing assembly 5 having a first clamp set 6 fixedly mounted to a base 7 and a second clamp set 8 movably mounted to the base. The second clamp set 8 is supported by a sliding bush and shaft arrangement 9, 10 and 11. 25 Each clamp set includes a pair of hydraulically operated mutually opposed jaws 12 and 13 which are releasably engagable with the cable 4. However, the invention is not limited to this form of clamping arrangement. Those skilled in the art will recognise that other clamping systems may be utilised to grip the tendon. 30 In the preferred embodiment, double acting hydraulic cylinders 14 and 15 are used to activate the first and second clamp sets 6 and 8 to clamp the cable 4 -7 therebetween. However, the double acting hydraulic cylinders 14 and 15 could be substituted by single double acting cylinders which activate the first and second clamp sets 6 and 8 to clamp the cable 4 therebetween. 5 The bulbing assembly 5 includes an actuator in the form of a hydraulic piston 16 with one end fixedly mounted to the base 7 and the other end movably mounted to the second clamp set 8. The piston 16 provides movement of the second clamp set 8 towards the first clamp set 6 during the bulbing process. In an alternative embodiment, the single actuator is substituted by two actuators located either side of the cable, each 10 actuator having one end fixedly mounted to the base 7 and the other end movably mounted to the second clamp set 8. It will be appreciated by those skilled in the art that other power sources such as electricity may be utilised to power the actuator/s. 15 The bulbing assembly 5 includes a set of driven front pinions 17 and a complementary pair of rear idler pinions 18 in gearing engagement with the parallel racks 2 for enabling the bulbing assembly 5 to move with respect to the cable 4. The front pinions 17 are preferably driven by a reversible, variable speed, hydraulic motor 20 with a built-in brake 19. A reversible, variable speed, electric motor with a brake could also be used for this purpose. It will be appreciated by those skilled in the art that the bulbing assembly 5 is not limited to being slidably mounted to the frame 1. Alternatively, the bulbing assembly 25 could be slidably mounted to a ceiling rail or the like which runs parallel to the cable. The cable bulbing apparatus includes one or more proximity sensors (not shown) for measuring the radial displacement of the bulb formed in the cable 4. The apparatus also includes an encoder 20 for controlling the movement of the pinions 17 along the 30 racks 2.

-8 In use, the cable 4 is laid across the length of the frame 1 with one end secured in the cable locking clamp 3 and the remainder running between the jaws 12 and 13 of the first and second clamp sets 6 and 8. In the preferred embodiment, the cable bolt locking clamp is activated by a single double acting hydraulic cylinder 21. 5 Oil pressure is then applied to the double acting hydraulic cylinders 14 and 15 to respectively clamp the cable bolt 4 between the jaws of the first and second clamp sets, as shown in Figure 1. 10 The hydraulic piston 16 is then activated to move the second clamp set 8 towards the first clamp set 6 forming a bulb in the cable 4, as shown in Figure 2. Radial displacement of the cable 4 is preferably controlled by a PLC control system using one or more proximity sensors to limit the radial displacement of the bulb 22. This is achieved by controlling the oil pressure on the underside of the hydraulic piston 16 to 15 stop the movement of the second clamp set 8 towards the first clamp set 6 when a desired displacement has been reached. Once the first bulb 22 is formed, oil pressure is applied to the hydraulic cylinders 14 and 15 to release the cable 4 from the jaws of the first and second clamp set 6 and 8. 20 Oil pressure is then applied to the topside of the hydraulic piston 16 which in turn moves the second clamp set 8 back to its starting position, as shown in Figure 1. If multiple bulbs are required, the reversible, variable speed, hydraulic motor with a built-in brake 19 is activated to drive the pinions 17 along the racks 2. This 25 allows the bulbing assembly to move along the frame 1 to align the first and second clamp sets 6 and 8 with the next desired bulbing location on the cable 4. The encoder 20 senses when the bulbing assembly 5 reaches the desired displacement from the most recently formed bulb 22 and sends a signal via the PLC control unit to the reversible, variable speed, hydraulic motor with a built-in brake 19 to stop rotation of 30 the pinions 17. The bulbing process can then be repeated. This process is continues until the desired number of bulbs are formed in the cable.

-9 Figures 3, 4 and 5 illustrate a cable bulbing apparatus 100 as an alternative embodiment to the cable bulbing apparatus 50. As the apparatus 100 includes many of the features of the earlier embodiment, like features have been given like reference numerals although they are prefixed by "100" to distinguish between embodiments. In 5 this embodiment the cable 104 can be displaced longitudinally relative to frame 101 by longitudinal movement of bulbing assembly 105. The cable bulbing apparatus 100 has a frame 101 with a pair of parallel racks 102, which can be distinguished from the earlier embodiment by the shorter length of 10 racks 102. Mounted to one end of the frame is a securing means in the form of a cable locking clamp 103, which is supplemented by a second cable locking clamp 130 mounted on the other end of the frame. The bulbing assembly 105 is displaceable relative to the frame 101 along the shortened racks 102. The features of the bulbing assembly 105 are similar to the earlier embodiment, with the exception of the bulbing 15 assembly 105 been adapted to secure and carry the cable bolt 104 when shuttling along the frame 101. Referring to Figure 3, the cable 104 is positioned onto the frame 101 and secured at one end by cable locking clamp 103 and the remainder running between the jaws 20 112 and 113 of the first and second clamps sets 106 and 108. The bulbing assembly 105 is located at a first position along the frame 101. A second cable locking clamp 130 remains open at this stage to allow longitudinal contraction of cable 104 during the bulbing process. To form bulb 122 the first and second clamp sets 106 and 108 clamp the cable 104, and the first clamp set 106 and second clamp set 108 are then displaced 25 relative to each other by hydraulic piston 116 as previously described. Once bulb 122 is formed as illustrated in Figure 3 the cable locking clamp 103 releases cable 104. Oil pressure is maintained in the hydraulic cylinders 114 and 115 in order to secure cable bolt 104 between the jaws of the first and second clamp sets 106 and 108 during the displacement of bulbing assembly 105. The hydraulic motor with built in brake 119 is 30 activated to drive pinions 117 along racks 102 to displace the bulbing assembly 105 and cable 104 longitudinally along frame 101. As illustrated in Figure 4 the bulbing assembly 105 is displaced to a second position along the frame which in turn causes - 10 the cable to advance (to the left as shown in the Figures). After displacement to a second position, the second cable locking clamp 130 and/or the first cable locking clamp 103 secures cable 104 relative to the frame and hydraulic cylinders 114 and 115 are actuated to release cable 104 from the jaws of the first and second clamp sets 106 5 and 108. The bulbing assembly 105 is then able to move back to, or towards, its first position (as shown in Figure 5), whilst the cable 104 remains fixed to the frame. In this regard the bulbing assembly 105 with the jaws 112 and 113 of the clamp sets 106 and 108 open are able to pass over the bulb 122 formed in the cable 104. 10 When the bulbing assembly 105 is located back in the first position on the frame 101, the second cable locking clamp 130 can be released and the first cable locking clamp 103 can be secured or remain secured to cable 104. A further bulb can now be formed by the bulbing assembly 105 as described above. This process may be repeated until the required number of bulbs are formed. 15 In a further embodiment it may be desirable to displace cable 104 longitudinally through the frame 101 without forming additional bulbs. This may be achieved as follows. The bulbing assembly 105 is located in the first position along frame 101. Either one or both of the jaws of the first and second clamp sets 106 and 108 then 20 secures cable 104. The step of activating hydraulic piston 116 is omitted thereby no bulb is formed. The cable locking clamp 103 and/or 130 is released and bulbing assembly 105 is displaced from the first position to the second position relative to the frame 101. Cable locking clamp 103 and/or 130 then secures cable 104 and the jaws of the first and second clamp sets 106 and 108 are released from cable 104. The 25 bulbing assembly 105 is then displaced back to the first position relative to frame 101. This step of displacing cable 104 may be desirable to adjust the spacing between multiple bulbs 122 of the cable 104, or to displace a cable blt from the cable bulbing machine to allow a subsequent cable to be fed. If it is required to space the bulbs at increments of the distance between the first and second positions, the bulbing 30 assembly 105 may shuttle between different positions on the frame so that the bulbs are formed at the required position.

- 11 It will be appreciated by those skilled in the art that various methods can be used for supplying cable to the apparatus. These include continuously feeding the cable from a reel or supplying cut lengths of cable. Cut lengths of cable can be fed to the apparatus manually, via a magazine, or via a pick and place style system. 5 When creating multiple bulbs in a cut length of cable, at the end of the bulbing process, the bulbing assembly 5 is driven to the far end 23 of the frame 1 by the reversible, variable speed, hydraulic motor with a built-in brake 19. The bulbed cable 4 is then removed from the cable bulbing apparatus either manually or via an automatic 10 means such as a pick and place style system. A subsequent cut length of cable bolt can then be supplied to the cable bulbing apparatus and the above process repeated. Supply of the cable can either be performed manually or by some form of automation controlled by the PLC control system. 15 The present invention has been described herein by way of example only. Ordinary workers in this field will readily recognise many variations and modifications which do not depart from the spirit and scope of the broad inventive concept.

Claims

1. An apparatus for forming one or more bulbs in a cable, the apparatus comprising: a frame; 5 securing means that is releaseably engageable with the cable; and a bulbing assembly comprising a base, and first and second clamp sets mounted to the base, the clamp sets of the bulbing assembly being releasably engagable with the cable and relative movement of said clamp sets forms a bulb in said cable; the bulbing assembly being movable relative to the frame independently of the 10 relative movement of the clamp sets; and the bulbing assembly being operative to form one or more bulbs in the cable by relative movement of the clamp sets and to reposition the cable relative to the frame to advance the cable through the apparatus by movement of the bulbing assembly relative to said frame independently of the relative movement of the clamp sets. 15

2. An apparatus according to claim 1 wherein the bulbing assembly is slidably mounted to the frame.

3. An apparatus according to claim 1 or 2 wherein the first and second clamp sets 20 each include a pair of hydraulically operated mutually opposed jaws for clamping said cable.

4. An apparatus according to any preceding claim wherein said first clamp set is fixedly mounted to said base and said second clamp set is movably mounted to said 25 base.

5. An apparatus according to any preceding claim wherein said bulbing assembly includes an actuator for providing said relative movement between said first and second clamp sets, said actuator being fixedly mounted to said base and in moving 30 engagement with said second clamping means. - 13

6. An apparatus according to claim 5 wherein said actuator is hydraulically powered.

7. An apparatus according to claim 5 wherein said actuator is electrically powered. 5

8. An apparatus according to any one of the preceding claims wherein said securing means is a cable locking clamp.

9. An apparatus according to claim 8, wherein the securing means further 10 comprises a second cable locking clamp.

10. An apparatus according to any preceding claim, further comprising a second actuator for providing relative movement of the bulbing assembly relative to the frame. 15

11. An apparatus according to claim 10, wherein the second actuator is hydraulically actuated.

12. An apparatus according to either claim 10 or 11wherein said frame includes a pair of parallel racks. 20

13. An apparatus according to claim 12 wherein said bulbing assembly includes a set of pinions in gearing engagement with said parallel racks for enabling said bulbing assembly to move along said frame under operation of said second actuator. 25

14. An apparatus according to claim 13 wherein said set of pinions includes a pair of driven front pinions and a complementary pair of rear idler pinions.

15. An apparatus according to any one of the preceding claims including one or more proximity sensors for measuring the radial displacement of the bulb formed in 30 the cable. - 14

16. An apparatus according to any one of the preceding claims including an encoder for controlling the movement of said bulbing assembly along said cable.

17. A method for forming bulbs in a cable, the method comprising the steps of. 5 positioning a cable on a frame; engaging a bulbing assembly at a first location on the cable, the bulbing assembly comprising first and second clamp sets configured to move relative to one another to form a bulb in the cable; forming a bulb in the cable at the first location by moving the clamp sets relative 10 to one another; repositioning the bulbing assembly relative to the frame whilst at least one of the first and second clamp sets of the bulbing assembly is engaged with the cable so that the cable is caused to advance; reengaging the bulbing assembly at a second location along the cable; and 15 forming a second bulb in the cable at the second location by again moving the clamp sets relative to one another.

18. A method according to claim 17 wherein said bulbing assembly is slidably mounted to a frame. 20

19. A method according claim 17 or claim 18 wherein relative movement of the clamp sets towards one another displaces a plurality of strands in the cable to form a bulb. 25

20. A method according to claim 19 including the steps of: releasing the cable from the first and second clamp sets; engaging said first and second clamping sets adjacent the second location on the cable; and moving the first and second clamp sets towards one another to form a second 30 bulb at the second location of the cable. - 15

21. A method according to any one of claims 17 to 20 wherein one or more proximity sensors sends a signal to stop the bulbing process when the strands of the cable reach a desired radial displacement. 5

22. A method according to any one of claims 17 to 21 wherein said cable is supplied to said bulbing assembly by a cable reel.

23. A method according to any one of claims 17 to 22 wherein said cable is supplied to said bulbing assembly by a pick and place style system. 10

24. A method according to any one of claims 17 to 23 wherein said cable is removed from said bulbing assembly by pick and place style system.

25. A method for forming one or more bulbs in a cable, said method comprising the 15 steps of: (a) positioning a cable on a frame; (b) positioning a bulbing assembly at a first position on said frame, the bulbing assembly comprising first and second clamp sets configured to move relative to one another to form a bulb in the cable; 20 (c) engaging the bulbing assembly at a first location on said cable; (d) forming the bulb in said cable at said first location; (e) repositioning the bulbing assembly to a second position on said frame whilst at least one of the first and second clamp sets of the bulbing assembly is engaged with the cable so that the cable is caused to move relative to the frame; 25 (f) releasing the bulbing assembly from the cable; (g) securing the cable relative to the frame; and (h) repositioning the bulbing assembly towards the first position on the frame.

26. A method according to claim 25 further comprising the step of: 30 (i) engaging said bulbing assembly at a second location on said cable after the bulbing assembly has been repositioned towards the first location. - 16

27. A method according to claim 26 further comprising the step of: (j) forming a second bulb in said cable at said second location.

28. A method according to either claim 26 or 27, further comprising the steps of: 5 (k) repeating steps (e) to (h); and (1) engaging said bulbing assembly at a third location on said cable.