REELING DEVICE

Abstract

A reeling device for the controlled coiling and uncoiling of a cable has a first end that is fixed and a second end that is movable relative to the first end. The cable is unbroken between its first and second ends. The reeling device includes first and second reels about which the cable is coiled. The first and second reels are coaxial. The first reel is fixed against rotation and axial movement, and the second reel is rotatable about the axis with such rotation causing axial movement of the second reel relative to the first reel.

Claims

1. A reeling device for the controlled coiling and uncoiling of a cable having a first end that is fixed and a second end that is movable relative to the first end, the cable is unbroken between its first and second ends, the reeling device comprising: first and second reels about which the cable is coiled, wherein the first and second reels are coaxial, the first reel is fixed against rotation and axial movement, and the second reel is rotatable about the axis with such rotation causing axial movement of the second reel relative to the first reel.

2. The reeling device as in claim 1, wherein an intermediate guide is provided for guiding the cable between the first and second reels.

3. The reeling device as in claim 2, wherein the intermediate guide is rotatable about the axis, wherein rotation of the intermediate guide causes axial movement of the intermediate guide.

4. The reeling device as in claim 3, wherein the rotation and axial movement of the second reel are proportional to the rotation and axial movement of the intermediate guide.

5. The reeling device as in claim 4, wherein a gear drive is provided for maintaining proportionality of the rotational and axial movement between the second reel and the intermediate guide.

6. (canceled)

7. The reeling device as in claim 2, wherein the intermediate guide comprises an arm, which comprises one or more guide members for guiding the cable with respect to the first and second reels.

8. The reeling device as in claim 7, wherein the arm comprises first and second guide members, wherein the first guide member overlaps with the first reel and the second guide member overlaps with the second reel.

9. The reeling device as in claim 7, wherein the one or more guide members each comprise one or more pulleys.

10. The reeling device as in claim 7, wherein the one or more guide members are retained in tangential alignment with the first and second reels respectively at all times.

11. The reeling device as in claim 1, wherein the first and second reels have the same diameter.

12. The reeling device as in claim 11, wherein the rotation and axial movement of the second reel are proportional to the rotation and axial movement of the intermediate guide, and wherein the rotation and axial movement of the second reel are double the speed of the rotation and axial movement of the intermediate guide.

13. The reeling device as in claim 1, wherein the first and second reels have different diameters.

14. The reeling device as claimed in claim 13, wherein the diameter of the first reel is smaller than the diameter of the second reel.

15. The reeling device as claimed in claim 14, wherein the second reel is arranged to surround at least a portion of the first reel in at least one axial position of the second reel.

16. The reeling device as claimed in claim 1, wherein the cable is helically coiled about each of the first and second reels in a single layer without overlap.

17. The reeling device as claimed in claim 1, wherein the first reel and/or the second reel comprises a helical groove for receiving the cable.

18. The reeling device as claimed in claim 1, wherein an end guide is provided for guiding the cable on and off the second reel.

19. The reeling device as claimed in claim 18, wherein the end guide is fixed against axial movement.

20. The reeling device as claimed in claim 18, wherein the end guide comprises a guide wheel.

21-22. (canceled)

23. The reeling device as claimed in claim 2, further comprising a plurality of intermediate guides for guiding a plurality of cables between the first and second reels, wherein each intermediate guide is arranged to guide a respective one of the plurality of cables between the first and second reels.

24. (canceled)

25. A system, comprising, a plurality of reeling devices, each reeling device as in claim 1; and a frame or device that is supported at the second ends of the cables of the plurality of reeling devices, wherein a controller is provided for synchronously coiling/uncoiling the cables for raising or lowering the frame or device.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0039] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

[0040] FIG. 1 is a front perspective view of a reeling device according to a first embodiment of the present invention.

[0041] FIG. 2 is a rear perspective view of the reeling device of FIG. 1.

[0042] FIGS. 3a and 3b are front elevation views of the reeling device of FIG. 1 with the cable fully coiled and fully uncoiled, respectively.

[0043] FIG. 4 is a sectional front view of the reeling device of FIG. 1.

[0044] FIG. 5 is a front elevation view of the reeling device of FIG. 1, in which an alternative arrangement of the intermediate guide is provided.

[0045] FIG. 6 is a sectional front view of a reeling device according to a second embodiment of the present invention.

[0046] FIG. 7 is a front perspective view of a reeling device according to a third embodiment of the present invention.

[0047] FIG. 8 is a front perspective view of a reeling device according to a fourth embodiment of the present invention.

[0048] FIGS. 9a and 9b are sectional front views of the reeling device of FIG. 8, with the second reel in first and second axial positions, respectively.

DETAILED DESCRIPTION OF THE INVENTION

[0049] With reference to FIGS. 1 to 4, there is shown a reeling device 1 according to a first embodiment of the present invention. The reeling device 1 is configured for the controlled coiling and uncoiling of a cable 2 having a first end 2a that is fixed and a second end 2b that is movable relative to the first end. The first end 2a is fixed to allow for a stationary connection to be made. The cable may support any suitable device at its second end. The cable may be an electrical cable or an optic fibre. In one exemplary arrangement a microphone (not shown) is supported and the cable 2 is an electrical cable. The cable 2 is unbroken between its first and second ends. The reeling device 1 comprises first and second reels 3, 4 about which the cable 2 is coiled. FIG. 3a shows the cable 2 fully wound/coiled and FIG. 3b shows the cable 2 fully unwound/uncoiled. The first and second reels 3, 4 are coaxial. The first reel 3 is fixed against rotation and axial movement. The second reel 4 is rotatable about the axis with such rotation causing axial movement of the second reel 4 relative to the first reel 3.

[0050] An intermediate guide 5 is provided for guiding the cable 2 between the reels 3, 4. The intermediate guide 5 in the present arrangement is rotatable about the axis, as is preferred. By such an arrangement, as seen in FIG. 2, the cable 2 can be guided substantially tangentially with respect to the second reel 4 at all times during reeling and unreeling of the cable. As is further preferred, rotation of the intermediate guide 5 in the present arrangement causes axial movement of the intermediate guide 5. By such axial movement, as seen in FIGS. 3a and 3b, the intermediate guide 5 is suitably axially aligned with the point of the second reel 4 at which the cable is fed on/off the second reel 4 at all times. The rotation and axial movement of the second reel 4 are preferably proportional to the rotation and axial movement of the intermediate guide 5 to achieve such a desired effect.

[0051] The intermediate guide 5, further, as it rotates, acts to coil/uncoil the cable from the first reel. In the present arrangement, as is preferred, the configuration of the intermediate guide 5 is such that the cable 2 is also guided substantially tangentially with respect to the first reel 3 at all times and such that the intermediate guide 5 is also suitably axially aligned with the point of the first reel 3 at which the cable is fed on/off the first reel 3 at all times.

[0052] In the present arrangement, the intermediate guide 5 comprises an arm 6 which comprises first and second guide members 7a, 7b. The arm 6 further comprises a support portion 34a (shown in a vertical orientation in FIGS. 3a and 3b) and a bridge portion 34b (shown in a horizontal orientation in FIGS. 3a and 3b). The support portion is directly or indirectly driven to rotate, by an electric motor in this embodiment. The first and second guide members 7a, 7b are located at or adjacent opposing ends of the bridge portion 34b of the arm 6.

[0053] The first guide member 7a guides the cable 2 with respect to the first reel 3 and the second guide member 7b guides the cable 2 with respect to the second reel 4. For such purposes, the first guide member 7a overlaps with the first reel 3 when viewed in a radial direction and the second guide member 7b overlaps with the second reel 4 when viewed in a radial direction. With reference to FIG. 3a, the first and second guide members fully overlap the first reel and second reels respectively. With reference to FIG. 3b, the first and second guide members partly overlap the first and second reels respectively.

[0054] In accordance with the discussion above, the points of the first and second guide members 7a, 7b at which the cable 2 is fed on/off the first and second guide members 7a, 7b are respectively axially aligned with the first and second reels 3, 4 at the points at which the cable 2 is fed on/off the first and second reels 3, 4.

[0055] The first and second guide members 7a, 7b comprise pulleys in the present arrangement, which is preferred to avoid wear on the cable. The guide members 7a, 7b could be otherwise arranged. They could, for example, be non-rotating and have a low-friction surface over which the cable 2 slides. By rotation of the arm 6, the guide members 7a, 7b (and the portion of cable extending between the guide members) maintain tangential alignment with the first and second reels 3, 4 at all times.

[0056] One possible alternative arrangement of the first and second guide members 7a, 7b is shown in FIG. 5. Here, the first and second guide members 7a, 7b each comprise a set of pulley sheaves 7c arranged in an arc. By this arrangement, the bend radius of the cable 2 passing over the first and second guide members 7a, 7b is defined by the angle of the arc of the pulley sheaves 7c. This arrangement may be particularly advantageous where the cable 2 has a relatively large minimum allowable bend radius, since the bend radius of the cable 2 can be increased without the need to use excessively large pulleys as the first and second guide members 7a, 7b. In a further alternative arrangement, the first and second guide members 7a, 7b could be replaced with a single larger pulley. In such a case, the points of the pulley at which the cable 2 is fed on/off the pulley will be respectively axially aligned with the first and second reels 3, 4 at the points at which the cable 2 is fed on/off the first and second reels 3, 4. In other words, the diameter of the single pulley would be suitably set.

[0057] In the present arrangement, as is preferred, the first and second reels 3, 4 have the same diameter as one another. This has a number of benefits, as will be readily appreciated by those skilled in the art, including simplifying the construction of the device. In alternative arrangements, however, the reels 3, 4 could have different diameters. With the first and second reels 3, 4 having the same diameter as one another, the rotation and axial movement of the second reel 4 will be double the speed of the rotation and axial movement of the intermediate guide 5 for maintaining positioning of the guide, as discussed above, with respect to the first and second reels 3, 4. The proportional speeds (rotationally and axially) will vary with relative changes to the diameters of the first and second reels 3, 4, as will be readily appreciated by those skilled in the art.

[0058] In the present arrangement, as best seen in FIG. 4, the intermediate guide 5 is rotatably driven by an electric motor 10. The motor 10 is preferably directly coupled (i.e. connected in a manner that does not rely on friction and so will not slip) to the intermediate guide 5. The motor 10 preferably comprises a servomotor. The servomotor may be combined with a gearbox in a single package to provide a servo drive. The motor/servo drive 10 is preferably housed within a drum of the first reel 3 as seen in FIGS. 1 and 4. A positional encoder will preferably be provided, which may take any suitable conventional form. Axial movement of the intermediate guide 5 is effected by virtue of a lead screw 8. A gear drive 9 is provided for transmitting rotary force to the second reel 4. Axial movement of the second reel 4 is also effected by the lead screw 8.

[0059] The gear drive 9 ensures that proportional rotational (and axial) movement between the second reel 4 and the intermediate guide 5 is maintained, which is preferable. In alternative arrangements, however, the gear drive 9 may be omitted. In arrangements omitting the gear drive 9, the second reel 4 will be loose with rotation of the second reel 4 effected by the frictional connection to the reeling and unreeling of the cable 2 alone.

[0060] One or more brakes are preferably provided. It is particularly preferable, as in the present arrangement, that a holding brake 12 is provided on the output side of the motor/drive gearbox (if used). Such a brake is preferably directly connected to a drum of the first reel 3, as shown in FIG. 4. The brake 12, preferably comprises an electromagnetic brake, as again shown in FIG. 4. The electromagnetic brake may take any conventional form. There may be additional brakes provided and/or positive-break direct struck limit switches.

[0061] As clearly shown in the figures, the cable 2 is helically coiled about each of the first and second reels in a single layer without overlap. This helps ensure accuracy throughout the life of the device. Either or both of the first and second reels 3, 4 may be provided with a helical groove for guiding/aligning the cable 2 as it is coiled, wherein the cable is received by the groove. In the present arrangement, both reels 3, 4 are provided with helical grooves. In alternative arrangements, the helical grooves may be omitted entirely.

[0062] With the axial movement of the second reel 4, as discussed, it is possible to provide a zero fleet reeling device, i.e. a device where the radial and axial location and the orientation of the portion of the cable adjacent the second end of the cable 2 that is fed on/off the second reel 4 does not change during reeling unreeling of the cable. This is again preferred for the purpose of ensuring accurate operation and ease of installation, for example where the cable is required to drop though a small hole in a ceiling. An end guide 11 is preferably provided for guiding the cable on/off the second reel 4. The end guide 11 is fixed against axial movement. In the present arrangement, the end guide 11 comprises a guide wheel 11a.

[0063] The drive mechanism will now be described in greater detail. It must be appreciated, however, that numerous modifications may be made without impacting the operation of the reeling device 1, as fundamentally defined by claim 1. The present invention is not to be limited to the exemplary drive mechanism described.

[0064] The motor/servo drive 10 rotates a splined shaft 13. The splined shaft 13 is fixed against axial movement. The lead screw 8 is fixed against both rotation and axial movement. A splined bush 14 engages the spline of the splined shaft 13. The splined bush 14 is fixed to a hollow shaft 15 that receives the splined shaft 13. The hollow shaft 15 threadably engages the lead screw 8. The intermediate guide 5 is fixed to the hollow shaft 15.

[0065] By the above arrangement, rotation of the splined shaft 13 effects rotation and axial movement of the intermediate guide 5.

[0066] As discussed, in the present arrangement, the gear drive 9 is provided. This comprises bevel gears 9a, 9b and 9c as shown in FIG. 4. Bevel gears 9a and 9b are mounted on the hollow shaft 15 via bearings to allow relative rotation therebetween. Bevel gear 9a is held against rotation relative to the first reel 3 by guide members 19. In the present arrangement, these are formed as tubes. In alternative arrangements they could be otherwise formed. Bevel gears 9c engage bevel gears 9a and 9b with their axes perpendicular thereto (and perpendicular to the motor/servo drive 10 axis). Bevel gears 9c are mounted on shafts 16 that extend radially outward from the hollow shaft 15 and are fixed to the hollow shaft 15 to rotate therewith. Bevel gears 9c are mounted on the shafts 16 via bearings to allow for suitable rotation. Guide tubes 17, which extend parallel to the motor/servo drive 10 axis are fixed with respect to the bevel gear 9b to rotate therewith. The guide tubes 17 are slidably received by bushes 18 that are fixed to the second reel 4 and are provided inside a drum of the second reel 4. The bushes 18 threadably engage the lead screw 8, which is static. Guide tubes 19 are similarly engaged in bushes within a support flange 20 of the fixed drum 3.

[0067] By the above arrangement, rotation of the splined shaft 13 effects rotation and axial movement of the second reel 4.

[0068] FIG. 6 shows a reeling device 21 in accordance with a second embodiment of the present invention, which comprises an alternative drive mechanism to the reeling device 1 of FIGS. 1 to 4. Corresponding features are indicated with like numerals.

[0069] Rotation and axial movement of the intermediate guide 5 are effected by rotation of the splined shaft 13 by the motor/servo drive 10, in substantially the same manner as described above with respect to the first embodiment. Splined bush 14 engages the spline of the splined shaft 13 and is fixed to a hollow shaft 15 that receives the splined shaft 14. In this embodiment, the hollow shaft 15 threadably engages the lead screw 8 via a threaded bush 22. The intermediate guide 5 is fixed to the hollow shaft 15 via the support portion 34a of the arm 6, to rotate therewith.

[0070] In place of gear drive 9, an alternative gear drive 23 is provided. Gear drive 23 comprises spur gears 23a, 23b, 23c and 23d. Spur gear 23a is fixed to an end of the splined shaft 13 to rotate therewith. Spur gear 23a engages with spur gears 23b. Spur gears 23c are coaxially fixed to spur gears 23b to rotate therewith. Spur gears 23c engage with spur gear 23d, which is mounted on a shaft portion 24 of the lead screw 8 via bearings to allow for rotation of spur gear 23d about the shaft portion 24. Guide tubes 17 are fixed to spur gear 23d via connecting arm 25, such that the guide tubes 17 rotate with spur gear 23d. The guide tubes 17 are slidably received by a bush 18 that is fixed to the second reel 4 and is provided inside a drum of the second reel 4. A threaded portion 18a of the bush 18 threadably engages the lead screw 8, which is static.

[0071] By the above arrangement, rotation of the splined shaft 13 effects rotation of the guide tubes 17 via the gear drive 23, which is turn effects rotation of the second reel 4. Rotation of the second reel 4 causes a concurrent axial movement of the second reel 4 by means of the threaded engagement of bush 18 with the static lead screw 8.

[0072] As also shown in FIG. 6, the reeling device 21 further comprises a pair of holding brakes 12a, 12b, which are directly connected to a drum of the first reel 3.

[0073] The end guide 11 of the reeling device 21 comprises a guide wheel 11a and a pulley 11b. In the illustrated embodiment, the pulley 11b is arranged to direct the cable 2 in a direction parallel with the axis of the first reel 3 and second reel 4. In alternative arrangements, the pulley may direct the cable 2 in any desired direction.

[0074] With reference to FIG. 7, there is shown a reeling device 26 in accordance with a third embodiment of the present invention. Features in common with the first embodiment are indicated with like numerals.

[0075] The reeling device 26 of the third embodiment comprises an intermediate guide assembly 27 comprising a plurality of intermediate guides 28, 29, 30 for guiding a plurality of cables 31, 32, 33 between the first and second reels 3, 4. A first intermediate guide 28 guides a first cable 31, a second intermediate guide 29 guides a second cable 32 and a third intermediate guide 30 guides a third cable 33. Each of the first, second and third intermediate guides 28, 29, 30 may be arranged with respect to the first reel 3 and the second reel 4 in the same manner as the single intermediate guide 5 described above with respect to the first embodiment of the present invention.

[0076] According to this arrangement, the reeling device can be used for coiling/uncoiling multiple cables without tangling of the cables. It will be appreciated that any number of intermediate guides may be provided according to the number of cables to be coiled/uncoiled using the reeling device.

[0077] In the arrangement shown in FIG. 7, the first, second and third intermediate guides 28, 29, 30 are rotationally fixed with respect to each other, such that the first, second and third intermediate guides 28, 29, 30 are rotatable about the axis with each other. Each intermediate guide comprises an arm 36 which comprises first and second guide members 35a, 35b, a support portion 34a and a bridge portion 34b. To achieve this rotation, the bridge portions 34b of the first, second and third intermediate guides 28, 29, 30 are all fixed to a common support portion 34a and thus form a unitary intermediate guide assembly 27. Rotation of the support portion 34a, and thus the first, second and third intermediate guides 28, 29, 30, is effected by rotation of a central shaft driven by a motor/servo drive of the reeling device 26, in substantially the same manner as described above with respect to the first embodiment of the present invention.

[0078] The first, second and third intermediate guides 28, 29, 30 guide the first, second and third cables 31, 32, 33, respectively, substantially tangentially with respect to the first reel 3 and the second reel 4 at all times during reeling and unreeling of the cable.

[0079] In the arrangement shown in FIG. 7, each of the first, second and third intermediate guides 28, 29, 30 comprises the first guide member 35a and the second guide member 35b connected by the bridge portion 34b of the arm 36. Each first guide member 35a guides a respective one of the first, second and third cables 31, 32, 33 with respect to the first reel 3. Each second guide member 35b guides a respective one of the first, second and third cables 31, 32, 33 with respect to the second reel 4.

[0080] In the arrangement described above, the first, second and third intermediate guides 28, 29, 30 are substantially identical in structure. However, it will be appreciated that, in embodiments of the present invention comprising a plurality of intermediate guides, the respective intermediate guides may adopt different structures to each other according to the requirements of the cables to be coiled/uncoiled using the reeling device.

[0081] With reference to FIGS. 8, 9a and 9b, there is shown a reeling device 37 in accordance with a fourth embodiment of the present invention. Features in common with the first embodiment are indicated with like numerals.

[0082] In the arrangement shown, the diameter of the first reel 3 is smaller than the diameter of the second reel 4. Accordingly, it is possible for the second reel 4 to move from an axial position in which there is no overlap between the first and second reels 3, 4 when viewed in a radial direction, as shown in FIG. 9a, to an axial position in which the first and second reels 3, 4 overlap when viewed in a radial direction, such that the second reel 4 surrounds the first reel 3, as shown in FIG. 9B. This configuration offers a more compact arrangement, which may be particularly beneficial when the reeling device 37 is being used to coil/uncoil larger cables, which will require a relatively large motor.

[0083] As shown in FIG. 8, the intermediate guide 5 is in the form of a single pulley. The diameter of the pulley is suitably set such that the points of the pulley at which the cable 2 is fed on/off the pulley are respectively axially aligned with the first and second reels 3, 4 at the points at which the cable 2 is fed on/off the first and second reels 3, 4.

[0084] The reeling device 37 comprises an alternative drive mechanism, which could also be used in any of the embodiments of the present invention hereinbefore described. With reference to FIGS. 9a and 9b, in particular, a motor/servo drive 10 rotates a splined shaft 13, which is fixed against axial movement. A splined bush 14 engages the spline of the splined shaft 13. The splined bush 14 is fixed to a hollow shaft 15, to which the intermediate guide 5 is fixed via arm 43 (shown in FIG. 8). Rotation of the splined shaft 13 therefore effects rotation of the hollow shaft 15 and the intermediate guide 5.

[0085] A roller 39 is fixed to one end of the hollow shaft 15. The roller 39 engages with the helical grooves of the first reel 3. Accordingly, rotation of the hollow shaft 15 effects axial movement of the hollow shaft 15 and the intermediate guide 5 via the roller 39. In an alternative arrangement, a series of rollers may be provided, the rollers being arranged helically to engage with the helical grooves of the first reel 3.

[0086] A gear drive 40 is provided to transfer rotational movement of the splined shaft 13 to the second reel 4. A spur gear 40a is fixed to the splined shaft 13 to rotate therewith. Spur gear 40a engages with spur gear 40b, which is coaxially fixed with spur gear 40c. Rotation of spur gear 40b effects rotation of spur gear 40c. Spur gear 40c engages with spur gear 40d, which is mounted on the shaft 13 via bearings to allow for independent rotation of spur gear 40d about the shaft 13. Guide tubes 17 are fixed to spur gear 40d via connecting arm 41, such that the guide tubes 17 rotate with spur gear 40d. The guide tubes 17 are slidably received by the second reel 4 inside a drum of the second reel 4, such that the second reel 4 rotates with the guide tubes 17.

[0087] A roller 42 engages with the helical grooves of the second reel 4. The roller 42 is fixed against axial movement. Accordingly, rotational movement of the second reel 4 effects axial movement of the second reel 4 via the roller 42. In an alternative arrangement, a series of rollers may be provided, the rollers being arranged helically to engage with the helical grooves of the second reel 4.

[0088] By the above arrangement, rotation of the shaft 13 effects rotation and axial movement of the second reel 4.

[0089] The above exemplary described arrangements provide a number of non-limiting exemplary benefits, including but not limited to the following:

[0090] 1. No break in the cable—so no degradation in signal quality/no interference.

[0091] 2. Accurate single layer wrap for the cable—enabling accurate positioning of a microphone (or other reeled electrical device (or optical data device using a fibre optic cable)) with no compression of the cable.

[0092] 3. Directly-coupled servo motor with positioning encoder—further enabling accuracy.

[0093] 4. High loads are possible (6 kg as configured in the depicted arrangement, compared to typical 1 kg on existing prior-art devices)—enabling the use of microphone ‘frames’ carrying multiple microphones. The ability to support such frames is enhanced by the ability to accurately position them, in line with 2 and 3 above.

[0094] 5. An adequately-sized holding brake on the output side of a drive gearbox (if used), directly connected to the splined shaft. Also, positive-break, direct struck limit switches. The brake and limit arrangement complies with current regulations pertaining to lifting loads over an audience.

[0095] 6. Adaptability—the device can be adapted to virtually any load/cable-type/stroke requirement.

[0096] 7. Virtually no cable is retained in the device when the cable is fully deployed, minimising cable run distance.

[0097] 8 The reeling device is ‘zero fleet’ i.e. the radial and axial location and the orientation of the portion of the cable adjacent the second end of the cable that is fed on/off the second reel does not change during reeling and unreeling of the cable. This provides the ability to locate the device directly over a hole in an auditorium ceiling for example.

[0098] The invention has been described above with reference to specific embodiments, given by way of example only. It will be appreciated that many different arrangements of the system are possible, which fall within the scope of the appended claims.