A reeling device

Abstract

A reeling device for the controlled coiling and uncoiling of a payload cable includes an axial shaft and a rotatable reel mounted thereon, a nut member and at least one roller mounted thereon, wherein the reel has an outer surface about which a length of cable is adapted to be wrapped, the nut member substantially surrounds the reel and is radially spaced from the outer surface of the reel which includes a helical groove for receiving one or more payload cables, and the roller is adapted to rotate while engaging the helical groove. A diverter sheave connected to the nut member is arranged to receive a payload cable from the reel and divert the payload cable in a first direction, and a concurrently moving compensator sheave is arranged to receive said payload cable from the diverter sheave and divert the payload cable in a different, second direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a 35 U.S.C. § 371 national phase filing of International Application No. PCT / GB2023 / 053290 filed on Dec. 18, 2023 and claims the benefit of United Kingdom Patent Application No. 2219031.8 filed on Dec. 16, 2022, wherein the entire disclosures of the foregoing applications are hereby incorporated by reference herein.TECHNICAL FIELD

[0002] The present invention relates to a reeling device for the controlled coiling and uncoiling of a payload cable.

[0003] Reeling devices such as winches may be used in the entertainment industry. They are designed to raise and lower a load connected to an end of a cable. For example, they are designed to lift and lower microphone cables, scenery or flying performers. Reeling devices may also be designed to slide scenery forwards and backwards across a stage in a horizontal direction, for example. Suitable payload cables are ropes and cables (including fibre-optic cables).

[0004] For supporting flying performers, it is particularly important that the reeling devices used are robust, strong and safe: they should be able to operate at high speeds, operate quietly and be sufficiently compact to fit in restricted spaces.

[0005] WO 2021 / 099800 A1 discloses an earlier invention from the present inventor. The reeling device disclosed comprises first and second reels about which a 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.

[0006] The present invention seeks to provide a different reeling device for the controlled coiling and uncoiling of a payload cable.SUMMARY

[0007] According to a first aspect of the present invention, there is provided a reeling device for the controlled coiling and uncoiling of a payload cable, the reeling device comprising an axial shaft and a reel mounted on the axial shaft for rotation about the axial shaft, a nut member and at least one roller mounted on the nut member, wherein

[0008] the reel has an outer surface about which a length of cable is adapted to be wrapped,

[0009] the nut member substantially surrounds the reel and is radially spaced from the outer surface of the reel,

[0010] the outer surface of the reel is provided with a helical groove for receiving one or more payload cables, and

[0011] the or each roller is adapted to rotate while engaging the helical groove,

[0012] the reeling device further comprising:

[0013] a diverter sheave directly or indirectly connected to the nut member and arranged to receive a payload cable from the reel and divert the payload cable in a first direction, and

[0014] a compensator sheave arranged to receive said payload cable from the diverter sheave and divert the payload cable in a second direction different to the first direction,

[0015] wherein the diverter sheave and compensator sheave are arranged for concurrent movement in the longitudinal direction of the axial shaft.

[0016] With the arrangement of the present invention, the diverter sheave can be aligned with the position at which the payload cable rolls on and off the reel in the longitudinal direction of the axial shaft. At the same time, the compensator sheave diverts the payload cable in a second direction for attachment of the payload cable to a load. Provision of a compensator sheave arranged according to the present invention has been found to significantly reduce the axial load acting on the roller. This results in less noise being generated by the roller bearing against the outer surface of the reel, improved efficiency of the reeling device and greater longevity of the device components (in particular, the roller). Additionally, the number of rollers required can be minimised without a loss in performance or load-bearing capacity of the reeling device.

[0017] In an embodiment where a bearing is provided for the roller, an axial load on the bearing is also beneficially reduced.

[0018] Preferably, the first direction and second direction are arranged such that, in use, when a payload cable is received by the reel, diverter sheave and compensator sheave and is in tension, an axial load acting on the or each roller in the longitudinal direction of the axial shaft resulting from tension of said payload cable is substantially zero. That is, the geometry of the payload cable(s) as determined by the diverter sheave and compensator sheave is preferably such that the cable tensions resolve to provide no (zero) resultant axial load on the nut member and, consequently, the or each roller. (The axial load will be zero except for a minimal horizontal component of the tension in the short section of cable between the reel and diverter, should the cable approach the reel at an angle other than 90 degrees to the reel axis. The cable may approach at the reel helix angle rather than exactly 90 degrees). This arrangement significantly reduces noise generated by the roller and nut member and improves the longevity of the roller. It will be appreciated that various different arrangements of the diverter sheave and compensator sheave are possible that are suitable for providing a zero axial load on the nut member and the or each roller. The exact arrangement may depend on factors such as, for example, the mechanism used to effect concurrent movement of the diverter sheave and compensator sheave and the angle at which the payload cable is diverted from the reel by the diverter sheave.

[0019] A rate of movement of the diverter sheave in a longitudinal direction of the axial shaft may be greater than a rate of movement of the compensator sheave in the longitudinal direction of the axial shaft during concurrent movement of the diverter sheave and the compensator sheave. Accordingly, a distance travelled by the diverter sheave in a longitudinal direction of the axial shaft is greater than a distance travelled by the compensator sheave in the longitudinal direction of the axial shaft. As the diverter sheave travels in the longitudinal direction of the axial shaft, the position at which the payload cable rolls on and off the reel changes. Therefore, the effective length of the payload cable will also change. With the above arrangement, the compensator sheave is able to at least partially compensate for this change in length of the payload cable as the diverter sheave travels in the longitudinal direction of the axial shaft.

[0020] Preferably, the rate of movement of the diverter sheave in a longitudinal direction of the axial shaft is two times greater than the rate of movement of the compensator sheave in the longitudinal direction of the axial shaft during concurrent movement of the diverter sheave and compensator sheave. Accordingly, a distance travelled by the diverter sheave in a longitudinal direction of the axial shaft is two times greater than a distance travelled by the compensator sheave in the longitudinal direction of the axial shaft. With this arrangement, the compensator sheave fully compensates for the change in effective length of the payload cable as the diverter sheave travels in the longitudinal direction of the axial shaft. The position of a load attached to an end of the payload cable is therefore independent of the position of the diverter sheave relative to the reel, and can be controlled by coiling and uncoiling of the payload cable from the reel. Thus, the position of a load on the end of a cable is solely determined by the rotation of the reel and is independent of the rotational direction in which the cable is wound onto the reel (i.e. clockwise or counter-clockwise).

[0021] The first direction may be parallel to the second direction. That is, the second direction may be arranged at approximately 180 degrees relative to the first direction. In such embodiments, the compensator sheave is arranged to divert the payload cable at an angle of approximately 180 degrees relative to the first direction. The first direction and / or the second direction may be parallel to the longitudinal direction of the axial shaft. In particularly preferred embodiments, the diverter sheave is arranged to receive the payload cable from the reel in a direction approximately perpendicular (i.e. perpendicular or near perpendicular) to the longitudinal direction of the axial shaft and to divert the payload cable approximately 90 degrees into the first direction that is parallel to the longitudinal direction of the axial shaft, and the compensator sheave is arranged to divert the payload cable approximately 180 degrees into the second direction.

[0022] The nut member may be mounted for movement in the longitudinal direction of the axial shaft and fixed against rotation about the axial shaft.

[0023] The diverter sheave may be directly or indirectly connected to the nut member to move with the nut member in a longitudinal direction of the axial shaft. Movement of the diverter sheave in the longitudinal direction of the axial shaft may be fixed relative to movement of the nut member in the longitudinal direction of the axial shaft. That is to say, the diverter sheave is arranged to move with the nut member at the same rate of movement.

[0024] The reeling device further may comprise a carriage which is arranged for movement in the longitudinal direction of the axial shaft and at least one of the nut member and the first diverter sheave is directly or indirectly connected to the carriage.

[0025] According to a second aspect of the present invention there is provided a reeling device for the controlled coiling and uncoiling of a payload cable, the reeling device comprising an axial shaft, a reel mounted on the axial shaft, a nut member and at least one roller mounted on the nut member, wherein

[0026] the reel has an outer surface about which a length of cable is adapted to be wrapped,

[0027] the nut member substantially surrounds the reel and is radially spaced from the outer surface of the reel,

[0028] the outer surface of the reel is provided with a helical groove for receiving one or more cables,

[0029] the or each roller is adapted to rotate while engaging the helical groove, and

[0030] the or each roller has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

[0031] In this aspect of the present invention, the radial plane of the roller passes through the distal end of a rim of the roller. A tangent at the distal end of the rim is parallel to the rotational axis of the roller.

[0032] The roller has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft in all radial directions.

[0033] Since the radial plane of the roller is inclined as described above, the load path is inclined and an axial load on the roller is beneficially reduced. Also, a radial component is added to all the forces acting on the roller.

[0034] In an embodiment where a bearing is provided for the roller, the load path is inclined and an axial load on the bearing is beneficially reduced. Also, a radial component is added to all the forces acting on the bearing.

[0035] As a result of the second aspect of the present invention, force is better directed over the roller as opposed to a case where the radial plane of the roller is perpendicular to the longitudinal direction of the axial shaft.

[0036] Also, since the radial plane of the roller is inclined, the roller is subjected to a rocking moment which acts to bring the roller in closer contact with the groove on the reel. This means that, should the roller rock in use, it will grip the groove tighter rather than pulling away from the groove.

[0037] The roller may be a tracking roller.

[0038] The reel may be directly or indirectly mounted on the axial shaft. The reel is preferably substantially cylindrical in shape. The reel may be metal or plastic or a composite material. For example, it may be steel or aluminium. In some embodiments, it is anodised aluminium or zinc-plated steel.

[0039] The reeling device may comprise more than one reel and the reels may be provided on the same axial shaft or they may be provided on separate axial shafts of the reeling device: the separate axial shafts may have their axes aligned.

[0040] In one embodiment, the reel has an outer surface about which the lengths of two cables are adapted to be wrapped. In use of the reeling device, the nut member may be located between the respective lengths of the two cables.

[0041] If the reeling device comprises two reels, a first reel may have an outer surface about which a length of at least a first cable is adapted to be wrapped and a second reel may have an outer surface about which a length of at least a second cable is adapted to be wrapped.

[0042] In use of the reeling device, a portion of the or each cable is preferably fixedly connected to the reeling device.

[0043] A first end of the cable may be fixed to the reeling device to allow a stationary connection to be made, for example when the cable is being used to carry signals or power. Alternatively, the first end of the cable may be attached to the reel, for example when the cable is used in a reeling device designed for ‘pure-lifting’. The cable may support any suitable object at an opposing second end.

[0044] The cable may be a synthetic rope or a wire rope or a metal rope or an electric cable or a fibre-optic cable, for example. A suitable synthetic rope is made of polyester. A suitable wire or metal rope is made of steel. These are non-limiting examples of suitable materials for the cable.

[0045] In use of the reeling device, the or each cable is preferably helically coiled about the outer surface of the reel in a single layer, i.e., without overlap in a direction perpendicular to the longitudinal direction of the axial shaft.

[0046] In one embodiment, the roller is adapted to rotate while engaging the helical groove at a point which has already been vacated by a cable: hence the roller is present where the cable is absent: the roller and the cable share the helical groove rather than having mutually exclusive helical grooves.

[0047] The helical groove preferably has a base portion in the form of an arc. In this regard, the base portion of the helical groove is to be understood as the innermost portion of the helical groove that lies closest to the axial shaft.

[0048] The components of the reeling device may be supported by a frame. The frame may be elongate in the longitudinal direction of the axial shaft.

[0049] The nut member may be a single, unitary member.

[0050] More than one nut member may substantially surround the or each reel.

[0051] The reeling device may therefore comprise another nut member which substantially surrounds the reel.

[0052] The nut member may be metal or plastic or a composite material. For example, it may be steel or aluminium.

[0053] In one embodiment, at least one roller is mounted on the nut member and faces generally towards a first end of the reeling device in an axial direction to provide a first-direction roller and at least one other roller is mounted on the nut member and faces generally towards an opposing second end of the reeling device in an axial direction to provide a second-direction roller. The first-direction roller may be a tension roller, which may be effective to resolve a payload tension in the cable. The second-direction roller may be a retract roller, which may be effective when there is no tension in the cable or when the reeling device is used without a cable attached.

[0054] In one embodiment, the first end of the reeling device is a front end of the reeling device and the second end of the reeling device is a rear end of the reeling device, such that the first-direction roller faces generally towards a front of the reeling device in an axial direction and the second-direction roller faces generally towards a rear of the reeling device in an axial direction. The front end of the reeling device may face in the direction in which a payload cable is adapted to be rolled on and off the reeling device.

[0055] In one embodiment, the nut member is substantially annular in shape and has a first annular face and an opposing second annular face, wherein the first annular face is positioned facing the first end (e.g., front end) of the reeling device and the second annular face is positioned facing the second end (e.g., rear end) of the reeling device: at least one tension roller is generally mounted on the first annular face and at least one retract roller is generally mounted on the second annular face.

[0056] The first annular face and / or the second annular face may not form a complete ring-shape as one or more arc-shaped spaces may be provided in the shape of the annular face.

[0057] A series of first-direction (tension) rollers may be provided, preferably spaced at substantially uniform intervals around the first annular face of the nut member.

[0058] A series of second direction (retract) rollers may be provided, preferably spaced at substantially uniform intervals around the second annular face of the nut member.

[0059] The nut member may comprise a plurality of nut member parts. For example, a plurality of substantially annular-shaped nut member parts may be arranged co-axially; or the nut member parts may be arc-shaped and together form a substantially annular shape. It is preferred that each nut member part has at least one roller mounted thereon but this is not essential.

[0060] In an embodiment where the nut member is provided by a plurality of nut member parts, one nut member part may provide the first annular face and another nut part member part may provide the second annular face.

[0061] The or each first-direction (tension) roller may have a radial plane which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in a first (e.g., forward) direction relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

[0062] The or each first-direction (tension) roller may have a radial plane which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in a first (e.g., forward) direction relative to the longitudinal direction of the axial shaft.

[0063] The or each second-direction (retract) roller may have a radial plane which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in an opposing second (e.g., rearward) direction relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

[0064] The or each second-direction (retract) roller may have a radial plane which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in an opposing second (e.g., rearward) direction relative to the longitudinal direction of the axial shaft.

[0065] In one embodiment, the radial plane of the or each first-direction roller and the radial plane of the or each second-direction roller are inclined at the same angle but in opposite directions relative to a plane which is perpendicular to the longitudinal direction of the axial shaft. This arrangement is preferred but optional.

[0066] In one embodiment, there is a greater number of first-direction (tension) rollers mounted on the nut member than there is second-direction (retract) rollers mounted on the nut member.

[0067] Alternatively, the number of first-direction (tension) rollers mounted on the nut member is the same as or smaller than the number of second-direction (retract) rollers mounted on the nut member.

[0068] The number of first-direction (tension) rollers mounted on the nut member may be in the range of 2 to 100, preferably 4 to 64 and more preferably 4 to 32. When a larger number of first-direction (tension) rollers are used, the reel may have a relatively large diameter and accommodate a relatively small diameter cable in the helical groove. In one embodiment, eight first-direction (tension) rollers are mounted on the nut member.

[0069] The number of second-direction (retract) rollers mounted on the nut member may be in the range of 1 to 50, preferably 2 to 32 and more preferably 2 to 16. When a larger number of second-direction (retract) rollers are used, the reel may have a relatively large diameter and accommodate a relatively small diameter cable in the helical groove. In one embodiment, three second-direction (retract) rollers are mounted on the nut member.

[0070] In one embodiment, the reel is mounted for rotation about the axial shaft. Upon rotation of the reel in one direction (e.g., clockwise direction), a cable is rolled on the reel. Upon rotation of the reel in an opposite direction (e.g., an anti-clockwise direction), a cable is rolled off the reel.

[0071] In use of the reeling device, at least one cable is wrapped around an outer surface of the reel. For example, one cable is wrapped around an outer surface of the reel or two cables may be wrapped around an outer surface of the reel.

[0072] In one embodiment, when the reel is mounted for rotation about the axial shaft and two cables are wrapped around an outer surface of the reel in use, upon rotation of the reel in one direction, a first cable is rolled on the reel and a second cable is rolled off the reel and, upon rotation of the reel in an opposite direction, the first cable is rolled off the reel and the second cable is rolled on the reel.

[0073] The first cable may be an outward line and the second cable may be a return line.

[0074] In another embodiment, when the reel is mounted for rotation about the axial shaft and five cables are wrapped around an outer surface of the reel in use, upon rotation of the reel in one direction, first to fourth cables are rolled off the reel and a fifth cable is rolled on the reel and, upon rotation of the reel in an opposite direction, the first to fourth cables are rolled on the reel and the fifth cable is rolled off the reel.

[0075] The first to fourth cables may be outward lines and the fifth cable may be a return line. Alternatively, the first to fourth cables may be return lines and the fifth cable may be an outward line.

[0076] In a further embodiment, when the reel is mounted for rotation about the axial shaft and five cables are wrapped around an outer surface of the reel in use, upon rotation of the reel in one direction, first to third cables are rolled off the reel and fourth and fifth cables are rolled on the reel and, upon rotation of the reel in an opposite direction, the first to third cables are rolled on the reel and the fourth and fifth cables are rolled off the reel.

[0077] The first to third cables may be outward lines and the fourth and fifth cables may be return lines. Alternatively, the first to third cables may be return lines and the fourth and fifth cables may be outward lines.

[0078] In yet another embodiment, the number of return lines equals the number of outward lines. For example, there may be one outward line and one return line or two outward lines and two return lines.

[0079] The invention is not limited to the number of cables to be wrapped around an outer surface of the reel in use of the reeling device.

[0080] The reel may be fixed against movement in the longitudinal direction of the axial shaft or may be mounted for movement in the longitudinal direction of the axial shaft.

[0081] In one embodiment, the reel is fixed against movement in the longitudinal direction of the axial shaft.

[0082] The reeling device may comprise an additional reel and optionally an additional nut member which substantially surrounds the additional reel.

[0083] The additional reel may be mounted on the axial shaft or mounted on another axial shaft.

[0084] More than one reel may be mounted on the axial shaft and / or on another axial shaft. For example, one or more reels are mounted on the axial shaft and one or more reels are mounted on another axial shaft.

[0085] If the reeling device comprises two or more reels, one reel may be fixed against movement in the longitudinal direction of the axial shaft and the other reel may be mounted for movement in the longitudinal direction of the axial shaft; or two reels may be fixed against movement in the longitudinal direction of the axial shaft; or two reels may be mounted for movement in the longitudinal direction of the axial shaft.

[0086] If the reeling device comprises two or more reels, one reel may be fixed against rotation about the axial shaft and the other reel may be mounted for rotation about the axial shaft; or two reels may be mounted for rotation about the axial shaft.

[0087] In one embodiment, the reeling device comprises first and second reels which are coaxial and the first reel is fixed against rotation and axial movement and the second reel is mounted for rotation about the axial shaft with such rotation causing axial movement of the second reel relative to the first reel. One reel or both reels may be substantially surrounded by at least one nut member.

[0088] In one embodiment, the nut member is mounted for movement in the longitudinal direction of the axial shaft and is fixed against rotation about the axial shaft.

[0089] The or each roller may be mounted for rotation about a connector, wherein the connector is directly or indirectly connected to the nut member. The connector is preferably fixed against rotation. The connector may be elongate. The connector may have a shaft.

[0090] An axis of the connector for the roller is preferably inclined relative to the longitudinal direction of the axial shaft of the reeling device.

[0091] In use of the reeling device, the roller rotates about the connector while engaging the helical groove. The rollers are urged to rotate by frictional contact with the helical groove.

[0092] The or each roller may comprise a rim, wherein the rim is adapted to engage the helical groove on the outer surface of the reel.

[0093] In use of the reeling device, the roller may engage the helical groove at a point which is located between a first cable wrapped about the reel and a second cable wrapped about the reel.

[0094] A rolling-element bearing may be provided to enable the roller to rotate. This bearing may be annular in shape.

[0095] The bearing may be located between the connector and the roller.

[0096] In one embodiment, the bearing comprises a plurality of balls or rollers, an inner race and an outer race, between which races the balls or rollers are adapted to run.

[0097] The inner race is adapted to be stationary in use and is directly or indirectly connected to the connector. In this regard, at least one bush may be provided to clamp the inner race. The or each bush may be located between the connector and the bearing.

[0098] The outer race is directly or indirectly connected to the roller and is adapted to rotate therewith. As the outer race rotates in use it causes the balls or rollers to rotate.

[0099] The or each roller may comprise an annular body. A tyre may be fitted to the annular body. If so, the rim of the roller may comprise the tyre.

[0100] The bearing may be located radially inward of the annular body.

[0101] In an embodiment where the roller comprises a bearing, the inclination of the roller acts to reduce the load on the bearing such that the roller operates without overloading the bearing.

[0102] The or each roller may include a base mounted directly or indirectly on the connector, a distal end opposite the base and a pair of sidewalls extending between the base and the distal end: the distal end engages the groove.

[0103] In one embodiment, the reeling device further comprises a carriage which is arranged for movement in the longitudinal direction of the axial shaft and the nut member is directly or indirectly connected to the carriage. The nut member is preferably indirectly connected to the carriage. The nut member may act to hold the carriage in place during use of the reeling device.

[0104] The nut member may be indirectly connected to the carriage via a bearing. In one example, the nut member is indirectly connected to the carriage by a bearing and torque arm arrangement: the bearing may be one or more spherical rod end bearings: one or more torque arms may interconnect the bearing and the nut member: the bearing may be directly or indirectly connected to the carriage.

[0105] The carriage may be provided with at least one diverter sheave for a cable. The diverter sheave may be adapted to deflect the cable to guide it substantially in the longitudinal direction of the axial shaft or to guide it in a direction substantially perpendicular to the longitudinal direction of the axial shaft onto the reel. The diverter sheave may be mounted for rotation about a transverse axis which extends across the width of the reeling device.

[0106] Rotation of the reel in use of the reeling device causes the roller(s) mounted on the nut member to travel in the helical groove: simultaneously, a payload cable is rolled on or off the helical groove via the diverter sheave and this effects rotation of the diverter sheave and thus linear movement of the carriage in the longitudinal direction of the axial shaft. The helical grooves have the effect of transporting the diverter sheave rather than the reel in the longitudinal direction of the axial shaft.

[0107] The diverter sheave is preferably a pulley which is mounted for rotation with its radial plane being substantially parallel to the longitudinal direction of the axial shaft.

[0108] In one embodiment, the carriage is provided with one diverter sheave per cable coiled and uncoiled by the reeling device.

[0109] In an embodiment where five cables are wrapped around an outer surface of the reel in use, five diverter sheaves are provided.

[0110] An outward diverter sheave is provided for the or each outward cable and a return diverter sheave is provided for the or each return cable.

[0111] If the reeling device is adapted to coil and uncoil a single cable, a single diverter sheave may be provided.

[0112] The carriage may comprise two opposing brackets which are preferably located on either side of the reel, these brackets opposing each other in a direction which is substantially transverse to the longitudinal direction of the axial shaft. The nut member may be positioned between the brackets of the carriage such that a radial plane of the nut member lies in a direction which is substantially transverse to the longitudinal direction of the axial shaft.

[0113] One or each bracket of the carriage may be provided with at least one diverter sheave for a cable, depending on the number of cables to be used.

[0114] In use of an embodiment of the reeling device, the bracket transmits force from the diverter sheave onto the nut member (either directly or indirectly) and therefore assists in resolving axial tension in the cable.

[0115] Preferably, when there is one or more outward cable and one or more return cable, the or each outward diverter sheave is provided on one bracket and the or each return diverter sheave is provided on the other bracket.

[0116] In one embodiment, a plurality of diverter sheaves is provided on a bracket: the diverter sheaves are spaced in the longitudinal direction of the axial shaft and spaced in correspondence with the relevant number of pitches of the helical groove on the reel: the bracket is extended in length in the longitudinal direction of the axial shaft to accommodate the diverter sheaves accordingly.

[0117] A plurality of diverter sheaves provided on a common bracket may be associated with a common nut member. Alternatively, each of a plurality of diverter sheaves provided on a common bracket may be associated with a corresponding separate nut member.

[0118] In another embodiment, each of a plurality of diverter sheaves are provided on a separate bracket and associated with a corresponding separate nut member, meaning that the number of diverter sheaves corresponds to the number of brackets and to the number of nut members.

[0119] The diverter sheave is preferably aligned in the longitudinal direction of the axial shaft with the point of the reel at which the cable is rolled on and off the reel at all times.

[0120] The reeling device of the present invention is preferably a ‘zero fleet’ reeling device. Such a reeling device is designed, along with any additional guiding means such as further diverter sheaves or guide wheels, such that the radial and axial location and the orientation of a portion of a cable does not change during reeling and unreeling of the cable. This provides the ability to locate the reeling device directly over a hole in an auditorium ceiling, for example.

[0121] The helical groove of the reel may be the source of a zero-fleet mechanism.

[0122] The or each payload cable is preferably unbroken between its first and second ends. The or each payload cable is preferably circular in cross-section.

[0123] The reeling device may comprise a carriage nut which is coaxial with the nut member. The carriage nut may be radially spaced from the outer surface of the reel. A bearing surface may be provided between the carriage nut and the nut member.

[0124] In one embodiment, the carriage nut is mounted between and connected to each bracket of the carriage at a connection point which comprises a bearing.

[0125] A motor for the reeling device may be located within the reel. Alternatively, a motor for the reeling device may located externally of the reel.

[0126] The reeling device may comprise a gearbox for the motor.

[0127] The reeling device may be a winch. It may be a direct drive winch.

[0128] The reel may be a drum. The helical groove may be a drum scroll.

[0129] The helical groove may have a multiple-start helix configuration.

[0130] One or more brakes may be provided, particularly where the axial shaft is driven by a motor.

[0131] Preferably, no separate lead screw is required to effect longitudinal movement of the carriage in the reeling device of the present invention.

[0132] A controller may be provided for controlled-motion coiling and uncoiling of the cables when raising or lowering an object.

[0133] Any of the features or embodiments described above in relation to the second aspect of the invention may be combined with the features or embodiments described above in relation to the first aspect of the present invention and vice versa. For example, the reeling device in accordance with the first aspect may be provided with one or more rollers having a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft, as described above in relation to the second aspect of the invention. It will be further appreciated that advantages and benefits of any features described above in relation to one aspect of the invention will be equally applicable where that same feature is incorporated into the other aspect of the present invention.

[0134] The present invention also provides a method of coiling and uncoiling at least one cable on a reel of the reeling device described above in relation to one or both of the first and second aspects of the present invention. In one embodiment, the method comprises coiling and uncoiling two cables on the same reel.

[0135] Further, the present invention provides the use of a reeling device described above in relation to one or both of the first and second aspects of the present invention to coil and uncoil at least one cable.BRIEF DESCRIPTION OF DRAWINGS

[0136] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0137] FIG. 1 is a front perspective view of a reeling device according to an embodiment of the present invention with a nut member in a rearward position;

[0138] FIG. 2 is a front perspective view of the reeling device of FIG. 1 with the nut member in a forward position;

[0139] FIG. 3 is top plan view of the reeling device of FIG. 1;

[0140] FIG. 4 is a side view of the reeling device of FIG. 1;

[0141] FIG. 5 is a longitudinal sectional view of the reeling device of FIG. 1 from one side;

[0142] FIG. 6 is a longitudinal sectional view of the reeling device of FIG. 1 from another side;

[0143] FIG. 7 is a transverse sectional view of the reeling device along line X-X of FIG. 3, looking towards a front end of the reeling device;

[0144] FIG. 8 is a rear perspective view of the nut member;

[0145] FIG. 9 is a longitudinal sectional enlarged view of part of the reeling device of FIG. 1 showing a roller;

[0146] FIG. 10 is a cross-sectional view of the body of the roller;

[0147] FIGS. 11a and 11b are perspective and front views of the roller, respectively;

[0148] FIGS. 12a to 12c are front, side and perspective views of the roller mounted on a connector, respectively;

[0149] FIG. 13 is a front perspective view of a reeling device according to a further embodiment of the present invention, with a nut member in a rearward position;

[0150] FIG. 14 is a rear perspective view of the reeling device of FIG. 13, with the nut member in a rearward position; viewed from the opposing end of the reeling device to FIG. 13.

[0151] FIG. 15 is a rear perspective view of the reeling device of FIGS. 13 and 14, with the nut member in a forward position;

[0152] FIG. 16 is a further rear perspective view of the of the reeling device of FIGS. 13 and 14, with the nut member in a forward position, viewed from the opposing side of the reeling device to FIG. 15;

[0153] FIG. 17 is a longitudinal sectional view of the reeling device of FIG. 13 from one side, with the nut member in a forward position;

[0154] FIG. 18 is a side view of the reeling device of FIG. 13, with the nut member in a forward position;

[0155] FIG. 19 is a side view of the reeling device of FIG. 13, with the nut member in a rearward position, and

[0156] FIG. 20 is a schematic view of a reeling device in accordance with a further aspect of the present invention.DETAILED DESCRIPTION

[0157] Referring to FIGS. 1 to 7, a reeling device 2 in accordance with one aspect of the present invention is shown. The reeling device 2 is a winch for the controlled coiling and uncoiling of two payload cables being a first payload cable 4 and a second payload cable 6.

[0158] The reeling device 2 comprises an axial shaft 8, a reel 10 mounted on axial shaft 8, a nut member 12 which is a travelling nut and a plurality of first-direction rollers 14 and a plurality of second-direction rollers 16 mounted on nut member 12.

[0159] Reel 10 has an outer surface about which a length of first payload cable 4 and a length of second payload cable 6 are coiled in use.

[0160] Nut member 12 substantially surrounds reel 10 and is radially spaced from the outer surface of reel 10.

[0161] The outer surface of reel 10 is provided with a helical groove 11 (see FIG. 9) for receiving first payload cable 4, second payload cable 6, first-direction rollers 14 and second-direction rollers 16. In use, these rollers engage the helical groove in a space between the payload cables.

[0162] First-direction rollers 14 and second-direction rollers 16 are adapted to rotate while engaging the helical groove. Rotation of these rollers effects axial movement of nut member 12.

[0163] Nut member 12 travels in the longitudinal direction of axial shaft 8 as the payload cables are paid out and pulled in from the reeling device.

[0164] Each first-direction roller 14 and second-direction roller 16 has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8.

[0165] In this embodiment, reel 10 is a cylindrical drum and helical groove 11 is a drum scroll.

[0166] In use of the reeling device, nut member 12 is located between the respective lengths of the two payload cables 4 and 6.

[0167] In use of the reeling device, a portion of each payload cable is connected and fixed to the reeling device. Referring to FIG. 4, an end portion of first payload cable 4 is connected and fixed at termination point 18 and an end portion of second payload cable 6 is connected and fixed at termination point 20. Termination point 18 is located at or towards the front end of reel 10 and termination point 20 is located at or towards the rear end of reel 10. Depending on the material of the payload cables, one or more standing turns of each payload cable on reel 10 may be provided at each termination point to provide additional friction.

[0168] Each payload cable is adapted to support a load at an opposing free end portion.

[0169] In use of the reeling device, as shown in the figures, each payload cable is helically coiled about the outer surface of reel 10 in a single layer, meaning that there is no overlap in a direction perpendicular to the longitudinal direction of axial shaft 8.

[0170] In this embodiment, the diameter of each payload cable is 6 mm and the reel pitch is 6.5 mm. Alternative payload cable diameters and pitches are possible.

[0171] As shown in FIGS. 1 to 8, first-direction rollers 14 face generally towards a front of the reeling device in an axial direction and second-direction rollers 16 face generally towards a rear of the reeling device in an axial direction. In use, first-direction rollers 14 are effective to resolve a payload tension in the cable. This is because both cables exit the reeling device at its front end and therefore generate tension in this direction only. Accordingly, first-direction rollers 14 are also referred to as tension rollers 14 in the following description of this embodiment of the present invention. Second-direction rollers 16 are effective when there is no tension in the cable or when the reeling device is used without a cable attached. Accordingly, second-direction rollers 16 are also referred to as ‘retract rollers’16 in the following description of this embodiment of the present invention.

[0172] Alternative arrangements are possible where tension could be generated in either of the opposing directions, in which case the second-direction (retract) rollers would function as tension rollers when the net sum of cable tensions results in a rearwards force.

[0173] The front end of the reeling device faces in the forward direction in which the payload cables are adapted to be rolled in and rolled off the reeling device.

[0174] First payload cable 4 is coiled around the portion of reel 10 between nut member 12 and the front end of the reel 10. Second payload cable 6 is coiled around the portion of reel 10 between nut member 12 and the rear end of the reel 10. Both payload cables are wound helically on reel 10, fitting within helical groove 11 on the outer surface of the reel.

[0175] Reel 10 is mounted for rotation about axial shaft 8. Upon rotation of the reel in one direction, first payload cable 4 is rolled on the reel and second payload cable 6 is rolled off the reel and, upon rotation of the reel in an opposite direction, first payload cable 4 is rolled off the reel and second payload cable 6 is rolled on the reel.

[0176] The first payload cable may be an outward line and the second payload cable may be a return line.

[0177] When the reeling device is used in a horizontal orientation, meaning that the longitudinal direction of the axial shaft extends substantially horizontally, the use of first and second payload cables as described above is useful for translational motion of an object.

[0178] In one example, two reeling devices 2 are mounted in opposite wings of a stage. The free end portions of first payload cable 4 and second payload cable 6 of a first reeling device are attached to one side of an item of scenery or a prop item and the free end portions of first payload cable 4 and second payload cable 6 of a second reeling device are attached to an opposite side of the item of scenery or the prop item.

[0179] As the respective payload cables are paid out and pulled in by the reeling devices, the item of scenery or the prop item can be pulled onto the stage and subsequently pulled off the stage, preferably in a sliding motion. The above arrangement may also be accomplished with a non-horizontal shaft by use of intermediate diverter sheaves for the ropes / cables such that the intermediate sheaves direct the cables / ropes in the required direction.

[0180] In another example, a reeling device 2 is mounted in each of three or more spaced locations above a stage. Typically, the reeling devices are not mounted in a straight line, although this is possible when a simple up-down motion is required. In this example, the devices may be equipped with a single cable and the free end portion of payload cable 4 of each reeling device is attached to attachment points on a harness of a performer or on an item of scenery.

[0181] As the respective payload cables are paid out and pulled in by the reeling devices, the performer or item of scenery is lifted above the stage and moved around in space to fly. This is known as ‘3D flying’ where, due to the layout of the devices in space, the item can be lifted vertically and traversed horizontally.

[0182] The reeling device may be provided with a single payload cable, for example for horizontal translational motion of an object. The nut member may be located forward or rearward of the cable. Bi-directional horizontal translation may be effected by using two payload cables being an outward line and a retract line.

[0183] The reeling device may also be used in a vertical orientation, meaning that the longitudinal direction of the axial shaft extends substantially vertically.

[0184] The payload cable or cables may extend vertically downwards from the reeling device in this orientation to provide a zero-fleet arrangement directly. If the reeling device is oriented vertically and mounted above a ceiling of a stage, for example, the payload cable or cables may drop through a hole in the ceiling to vertically raise and lower a microphone cable or a prop item, for example.

[0185] With reference to FIGS. 5 and 6, an electro-magnetic motor 17 for the reeling device is located substantially within the reel. This contributes to providing a compact design for the reeling device.

[0186] When there is restricted space to accommodate a reeling device, for example above a stage, the compact design of the reeling device is useful.

[0187] The reeling device is gearless in this embodiment: rotation of the axial shaft effects rotation of the reel without the need for a gear set to transfer rotational or axial movement between the components.

[0188] In other embodiments, the reeling device comprises a gear: for example, a gear set may be used to synchronise two reels. Alternatively, a gearbox may be used to connect an external motor to the shaft.

[0189] In this embodiment, reel 10 is mounted for rotation about axial shaft 8 and fixed against movement in the longitudinal direction of axial shaft 8. Nut member 12 is mounted for movement in the longitudinal direction of axial shaft 8 and is fixed against rotation about axial shaft 8.

[0190] Referring to FIG. 8, nut member 12 is substantially annular in shape and has a first annular face 21 and an opposing second annular face 22, wherein first annular face 21 is positioned facing the front end of the reeling device and second annular face 22 is positioned facing the rear end of the reeling device.

[0191] In this embodiment, nut member 12 is an annular ring which surrounds reel 10. Nut member 12 has an inner diameter which is greater than the outer diameter of reel 10, such that nut member 12 is radially spaced from the outer surface of reel 10.

[0192] In this embodiment, first annular face 21 and second annular face 22 form a complete ring-shape but this is not essential: for example, one or more arc-shaped spaces may be provided in the shape of one or both annular faces.

[0193] A plurality of first-direction (tension) rollers 14 is generally mounted on first annular face 21 and a plurality of second-direction (retract) rollers 16 is generally mounted on second annular face 22.

[0194] Eight first-direction (tension) rollers 14 are spaced at substantially uniform intervals around first annular face 21 of nut member 12.

[0195] Three second-direction (retract) rollers 16 are spaced at substantially uniform intervals around second annular face 22 of nut member 12.

[0196] First-direction (tension) rollers 14 and second-direction (retract) rollers 16 are mounted on nut member 12 at fixed locations.

[0197] In this embodiment, there is a greater number of first-direction (tension) rollers 14 than second-direction (retract) rollers 16 because both payload cables enter and exit the reeling device from its front end, being the payload end. This means that there is a greater forward tension than rearward tension on nut member 12. Accordingly, the retract side may be less strong than the tension side and more tension rollers than retract rollers may be useful to keep the nut member stable.

[0198] Nut member 12 is provided with a torque arm 23 which is supported on a pair of interconnected spherical rod end bearings 24 which are visible in FIGS. 5 to 7. The spherical rod end bearings interconnect torque arm 23 and carriage 42. The connection of the torque arm 23 prevents rotation of nut member 12 in use of the reeling device.

[0199] Referring to FIGS. 9 to 11, each first-direction (tension) roller 14 and each second-direction (retract) roller 16 comprises an annular body 25 having a rim 26. In this embodiment, a tyre is fitted to the annular body. Accordingly, the rim 26 of each roller comprises a tyre. The presence of a tyre is optional. The tyre may be polyurethane or hard nylon, for example.

[0200] The annular body of each roller may be metal (e.g., aluminium or stainless steel) or plastic or a composite material.

[0201] In one embodiment, the inner diameter of annular body 25 is 27 mm; the outer diameter of the roller (including any tyre) is 41 mm; and the width of the roller is 12 mm.

[0202] With reference to FIG. 9, a radial plane P passes through distal end 26e of rim 26 of each roller. A tangent at distal end 26e is parallel to the rotational axis of the roller.

[0203] Each roller is inclined at angle α relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8. Accordingly, each roller is inclined at angle β relative to the longitudinal direction of axial shaft 8.

[0204] In one embodiment, the cross-sectional profile of the leading portion of rim 26 is at an angle α relative to the radial plane P of the roller. Such a cross-sectional profile is shown in FIG. 10 which is a cross-sectional view taken though line A-A of FIG. 11b. The leading portion of rim 26 is the tension portion of the rim, being the front-facing portion of rim 26 in this embodiment.

[0205] Each first-direction (tension) roller 14 has radial plane P which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in a forward direction relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8. In one embodiment, angle α is 24 degrees.

[0206] Accordingly, each first-direction (tension) roller 14 has radial plane P which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in a forward direction relative to the longitudinal direction of the axial shaft. In one embodiment, angle β is 66 degrees.

[0207] Each second-direction (retract) roller 16 has radial plane P which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in a rearward direction relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8. In one embodiment, angle α is 24 degrees.

[0208] Accordingly, each second-direction (retract) roller 16 has radial plane P which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in a rearward direction relative to the longitudinal direction of the axial shaft. In one embodiment, angle β is 66 degrees.

[0209] In this embodiment, the radial plane of each first-direction (tension) roller 14 and the radial plane of each second-direction (retract) roller 16 are inclined at the same angle but in opposite directions relative to a plane which is perpendicular to the longitudinal direction of axial shaft 8.

[0210] Referring to FIGS. 8 and 9, a ball-bearing 28 is provided to enable rotation of each first-direction (tension) roller 14 and second-direction (retract) roller 16. The bearing is annular in shape and comprises a plurality of balls 30, an inner race 32 and an outer race 34, between which the balls are adapted to run. Ball-bearing 28 is located radially inward of annular body 25.

[0211] Each roller is mounted on nut member 12 using a connector 36 and a pair of shaft bushes 38. Shaft bushes 38 act to clamp inner race 32 of ball bearing 28 in place. As shown in FIG. 9, shaft bushes 38 are provided with annular shoulder portions which accommodate and fix inner race 32.

[0212] Shaft bushes 38 are located between connector 36 and ball-bearing 28. Ball-bearing 28 is located between shaft bushes 38 (which surround connector 36) and annular body 25. Inner race 32 is adjacent shaft bushes 38. Outer race 34 is adjacent annular body 25.

[0213] Connector 36 is provided with a screw thread for connection to a threaded aperture 40 provided in nut member 12. Once connected, connector 36 is fixed against rotation.

[0214] Each roller is mounted for rotation about the axis of connector 36.

[0215] Connector 36 may be a socket head cap screw or a counter sunk screw, for example.

[0216] Inner race 32 is stationary in use, relative to nut member 12. Outer race 34 is adapted to rotate with annular body 25 of the roller. As the outer race rotates in use it causes balls 30 to rotate.

[0217] In use of the reeling device, each first-direction (tension) roller 14 and each second-direction (retract) roller 16 rotates about the shaft of connector 36 while engaging helical groove 11. Rim 26 of each roller engages the helical groove on the outer surface of reel 10: the profile of rim 26 is shaped to fit snugly in the profile of the groove. Each roller is urged to rotate by frictional contact with the helical groove.

[0218] In this embodiment, the axis of connector 36 is inclined at angle α relative to the longitudinal direction of axial shaft 8 of the reeling device. The rotational axis of each roller is therefore inclined relative to the rotational axis of reel 10.

[0219] In use, reel 10 is driven to rotate about axial shaft 8 such that first-direction (tension) rollers 14 and second-direction (retract) rollers 16 progress along helical groove 11. Nut member 12 consequently moves in the axial direction of reel 10.

[0220] In this embodiment, nut member 12 moves forward in use between the rear and front ends of reel 10 and moves backwards in use between the front and rear ends of reel 10. In FIG. 1, nut member 12 is positioned closer to the rear end of reel 10. In FIG. 2, nut member 12 is positioned closer to the front end of reel 10.

[0221] Nut member 12 is located between first payload cable 4 coiled on reel 10 and second payload cable 6 coiled on reel 10.

[0222] First-direction (tension) roller 14, second-direction (retract) roller 16, first payload cable 4 and second payload cable 6 share the same helical groove rather than having mutually exclusive helical grooves.

[0223] In general terms, each roller includes a base 27 mounted directly or indirectly on the connector 36, a distal end 26e opposite the base and a pair of sidewalls 29 extending between base 27 and distal end 26e, as shown in FIG. 10. Distal end 26e engages groove 11, as shown in FIG. 9.

[0224] Reeling device 2 comprises a carriage 42 which is arranged for movement in the longitudinal direction of axial shaft 8 along track 44 which is a linear slide track: nut member 12 is connected indirectly to carriage 42.

[0225] Carriage 42 is provided with a diverter sheave 46 for each payload cable. Diverter sheave 46 deflects the payload cable it guides by approximately 90 degrees. For example, when the payload cable is being paid out, the payload cable is diverted from being substantially perpendicular to the longitudinal direction of axial shaft 8 to being substantially parallel to the longitudinal direction of axial shaft 8; and when the payload cable is being pulled in, the payload cable is diverted from being substantially parallel to the longitudinal direction of axial shaft 8 to being substantially perpendicular to the longitudinal direction of axial shaft 8.

[0226] In this embodiment, diverter sheave 46 is a pulley which is mounted for rotation with its radial plane being substantially parallel to the longitudinal direction of axial shaft 8.

[0227] Carriage 42 comprises two opposing brackets 42b which are located on either side of reel 10, these brackets opposing each other in a direction which is substantially transverse to the longitudinal direction of axial shaft 8. Nut member 12 is located between the brackets of the carriage such that a radial plane of the nut member lies in a direction which is substantially transverse to the longitudinal direction of the axial shaft. Between brackets 42b, carriage 42 extends beneath reel 10 (as shown in FIG. 7).

[0228] In this embodiment, as shown in FIGS. 1 to 7, each bracket 42b of carriage 42 is provided with one diverter sheave 46.

[0229] Helical groove 11 has the effect of transporting diverter sheave 46 in the longitudinal direction of axial shaft 8.

[0230] Diverter sheave 46 for second payload cable 6 is shown in FIGS. 1, 2, 6 and 7: diverter sheave 46 for first payload cable 4 is shown in FIGS. 4 and 5.

[0231] Each diverter sheave 46 is aligned in the longitudinal direction of axial shaft 8 with the point of reel 10 at which the payload cable to be diverted is rolled on and off the reel at all times. Hence diverter sheave 46 for first payload cable 4 is positioned closer to the front end of the reeling device than diverter sheave 46 for second payload cable 6.

[0232] As reel 10 rotates in use of the reeling device, one of the payload cables is rolled on the reel and the other payload cable is rolled off the reel. One diverter sheave 46 receives the payload cable being rolled off the reel and diverts it by approximately 90 degrees, guiding the payload cable in a forward direction which is substantially parallel to axial shaft 8. Meanwhile, the other diverter sheave receives the other, paid out payload cable from a direction which is substantially parallel to axial shaft 8 and diverts it by approximately 90 degrees, guiding the payload cable in a rearward direction and then diverting it as it is pulled towards and rolled on the reel.

[0233] With reference to FIGS. 1 and 2, in the case where nut member 12 travels from the rear end to the front end of reel 10, the length of first payload cable 4 rolled on reel 10 decreases and the length of second payload cable 6 rolled on reel 10 increases. The first-direction (tension) rollers and the second-direction (retract) rollers are guided along the helical groove, causing the nut member to slide towards the front end of reel 10.

[0234] Nut member 12 is positioned between the lengths of the first and second payload cables rolled on reel 10. Diverter sheaves 46 and thus carriage 42 move axially along track 44 at the same rate as nut member 12, such that the diverter sheaves are always in the same position relative to the points at which their respective payload cables roll on and off reel 10. As shown in FIGS. 1 to 6, the lengths of the first and second payload cables which are not rolled on reel 10 each enter / leave the body of the reeling device at respective predetermined, stable positions.

[0235] Nut member 12 surrounds reel 10 and is radially spaced from the outer surface of the reel. Referring to FIG. 8, nut member 12 has three arc-shaped bushes 48 connected to second annular face 22. A rear-facing outer surface of each bush 48 is shaped as a portion of a spherical segment: together the three bushes provide a convex spherical bearing surface. Each bush 48 abuts a carriage nut 50 which is substantially annular. The carriage nut is radially spaced from the outer surface of reel 10.

[0236] Spring member 54 extends between carriage nut 50 and nut member 12. In this embodiment, there are two spring members 54 which are each located on diametrically opposite sides of nut member 12 and carriage nut 50 as shown in FIG. 7.

[0237] Carriage nut 50 is mounted between and connected to each bracket 42b of carriage 42 at a connection point 52. Referring to FIG. 7, connection point 52 provides a bearing 52b (e.g., a plastic bearing in a top hat shape) and a connector 52c (e.g., a socket head cap screw) passing through the bearing to connect the bracket to the carriage nut. Connection point 52 in this embodiment also provides a sandwich of annular steel plates 52p which are screwed together and surround bearing 52b. An aperture is provided in each bracket 42b at each connection point 52 to accommodate plates 52p, bearing 52b and connector 52c and thereby enable sliding and rotation of carriage nut 50 about bearing 52b.

[0238] Carriage nut 50 provides an annular concave surface to abut the convex spherical bearing surface provided by the rear-facing outer surfaces of bushes 48. The mating of these concave and convex surfaces, together with the mounting of torque arm 23 and the movement provided at connection point 52, allow nut member 12 to move slightly relative to track 44 thus accommodating deflection and flex of the structure of the reeling device as a load is lifted in use of the device.

[0239] By carrying diverter sheaves 46, brackets 42b are able to transmit force from the diverter sheaves and reel onto nut member 12 via the mounting arrangement of nut member 12 described above and thereby resolve axial tension in the cables in use of the reeling device.

[0240] This mounting arrangement of nut member 12 provides a sliding, gimbal-like mechanism to accommodate some flex and movement of nut member 12 in response to tension changes in the payload cables.

[0241] This mounting arrangement and mechanism are present in the present embodiment to accommodate real world limitations of the exemplified reeling device but they are not essential to the present invention.

[0242] A safety nut 56 is also provided and is coaxial with carriage nut 50 and nut member 12. Safety nut 56 is configured to move in the longitudinal direction of axial shaft 8 at the same rate as carriage nut 50 and nut member 12. Carriage nut 50 is located between nut member 12 and safety nut 56 in FIGS. 3 to 6: with reference to FIG. 9, safety nut 56 extends beneath carriage nut 50 and nut member 12 in the axial direction.

[0243] Safety nut 56 sits independently within groove 11. A small space is provided between safety nut 56 and nut member 12 in the axial direction. When there is wear or other problems with the tension or retract rollers, tension in the payload cable(s) will tend to pull nut member 12 away from the safety nut. The space between safety nut 56 and nut member 12 in the axial direction is monitored and a warning system is triggered if the space increases beyond a certain limit. The warning system shuts down the operation of the reeling device.

[0244] With reference to FIG. 9, safety nut 56 is substantially annular and is provided with a radially-protruding portion having an aperture through which a peg 58 extends in a direction parallel to axial shaft 8. Peg 58 is provided with a screw thread for connection to a threaded aperture provided in carriage 50. Once connected, peg 58 is fixed against rotation. Peg 58 has a shaft and a flange 60 located along the shaft. One end of the shaft is fixed in carriage 50. Flange 60 fits within the aperture in the radially-protruding portion of the safety nut. When reel 10 rotates, light friction between the reel and the safety nut exerts a torque about the safety nut; flange 60 prevents safety nut 56 from rotating as a result of this torque.

[0245] Should the space between nut member 12 and safety nut 56 increase by more than the width of flange 60, the flange moves in an axial direction away from the aperture in the radially-protruding portion. Once flange 60 is located externally of the aperture in the axial direction, only a free end of the shaft of peg 58 is accommodated in the aperture. Since the shaft of peg 58 has a smaller diameter than flange 60, safety nut 56 rotates slightly. This rotation triggers the warning system.

[0246] The operation of the reeling device in its other aspects will be clear to a person skilled in the art from FIGS. 1 to 12 and from the following components which are labelled in the figures.

[0247] A cable chain 62 for electric cables extends in the longitudinal direction of axial shaft 8. The electric cables are connected to load cells 64. A load cell 64 is mounted on each side of carriage 42 and measures the force on the adjacent diverter sheave 46 and thus the force of the payload cable guided by the diverter sheave.

[0248] Electro-magnetic motor 17 comprises a series of motor stators 66 which are co-axial with reel 10 and located within the reel. In this embodiment, five motor stators are used, connected by stator-to-stator link cables 67. Motor stators 66 are surrounded by a cylindrical magnet 68 which in turn is surrounded by a cylindrical iron rotor 69, as shown in FIGS. 5 to 7. Magnet 68 and rotor 69 are co-axial with reel 10 and located within the reel.

[0249] An electrical connector box 70 is provided towards the rear end of the reeling device: cable glands 72 each feed a rear-end electrical item into the connector box; cable glands 74 each feed a front-end electrical item into the connector box.

[0250] Electrical connector box 70 contains housing 76 for spark quenchers, for example. It also contains a terminal block 78 mounted for electrical connections.

[0251] Mounted above electrical connector box 70 is a brake 80 (for example, a two rotor / two coil / double brake or a stage brake). Rearwards of brake 80 is a module connector 82.

[0252] A housing 84 containing a rotary limit switch 86 is provided at the front end of the reeling device. Between housing 84 and motor 17, a coaxial cooling fan 88 is provided inside reel 10.

[0253] The components of the reeling device are supported by an external frame 90 which is elongate in the longitudinal direction of axial shaft 8. In this regard, frame 90 supports, inter alia, brake 80 and housing 84 and reel 10 is mounted therebetween in the longitudinal direction of axial shaft 8.

[0254] In another embodiment, four payload cables replace single payload cable 4. Three additional diverter sheaves 46 are mounted on carriage 42. There is a commensurate reduction in stroke per cable and the axial length of reel 10 is increased. A load pin is provided on each diverter sheave.

[0255] Referring now to FIGS. 13 to 19, there is shown a reeling device 102 in accordance with a further aspect of the present invention. Reeling device 102 is of similar construction to reeling device 2 described above with reference to FIGS. 1 to 7. Equivalent features are shown with corresponding numerals and description thereof will not be repeated.

[0256] In FIGS. 13 to 19, various features including housing 184 and external frame 190 (corresponding to housing 84 and external frame 90 of the previous embodiment) are omitted for clarity. It will be appreciated that the exclusion of such features from FIGS. 13 to 19 does not restrict their inclusion in the embodiments described hereafter. That is, features of the embodiments described above with reference to FIGS. 1 to 12 may be included in the embodiments described below with reference to FIGS. 13 to 19, even if such inclusion is not expressly described below.

[0257] As for the previously described embodiment, reeling device 102 comprises a reel 110 mounted on an axial shaft 108 (shown most clearly in FIG. 17) and a nut member 112 substantially surrounding reel 110 and radially spaced from the outer surface of reel 110. Nut member 112 is arranged to travel in the longitudinal direction of axial shaft 108 as the payload cables are paid out and pulled in from reeling device 102 and is fixed against rotation about axial shaft 108. In this embodiment, nut member 112 has a spherical mounting arranged to transmit a (lower) axial force equally in both directions; whereas in the first embodiment, the spherical bearing was arranged to transmit an axial force in predominantly one direction.

[0258] Nut member 112 comprises first-direction rollers 114 and second-direction rollers 116 that engage a helical groove 111 provided in the outer surface of reel 110. Rotation of first-direction rollers 114 and second-direction rollers 116 effects axial movement of nut member 112 as described above.

[0259] Arrangement of nut member 112, including first-direction rollers 114 and second-direction rollers 116, may be substantially as described above and description thereof will not be repeated.

[0260] First payload cable 104 and second payload cable 106 are fixed to the reeling device 102 and are helically coiled about the outer surface of reel 110 as described above. Nut member 112 is located between the respective lengths of the two payload cables 104, 106.

[0261] Reel 110 is mounted for rotation about axial shaft 108. Upon rotation of the reel in one direction, first payload cable 104 is rolled on the reel and second payload cable 106 is rolled off the reel and, upon rotation of the reel in an opposite direction, first payload cable 104 is rolled off the reel and second payload cable 106 is rolled on the reel.

[0262] Reeling device 102 comprises a first diverter mechanism comprising a first diverter sheave 146a arranged to receive first payload cable 104 from reel 110, and a first compensator sheave 147a arranged to receive first payload cable 104 from first diverter sheave 146a. When being rolled off reel 110, first payload cable 104 passes from reel 110 to first diverter sheave 146a and subsequently to first compensator sheave 147a.

[0263] First diverter sheave 146a diverts first payload cable 104 in a first direction D1 parallel to the longitudinal direction of axial shaft 108. First compensator sheave 147a diverts first payload cable 104 in a second direction D2 parallel to the longitudinal direction of axial shaft 108. As can be seen in FIGS. 13 to 15, in particular, first compensator sheave 147a diverts first payload cable 104 substantially 180 degrees relative to the first direction D1. The first direction D1 is parallel to the second direction D2 and opposes the second direction D2.

[0264] Reeling device 102 further comprises a second diverter mechanism comprising a second diverter sheave 146b arranged to receive second payload cable 106 from reel 110, and a second compensator sheave 147b arranged to receive second payload cable 106 from the second diverter sheave 146b. When being rolled off reel 110, second payload cable 106 passes from reel 110 to second diverter sheave 146b and subsequently to second sheave 147b.

[0265] Second diverter sheave 146b diverts second payload cable 106 in a third direction D3 parallel to the longitudinal direction of axial shaft 108. Second compensator sheave 147b diverts second payload cable 106 in a fourth direction D4 parallel to the longitudinal direction of axial shaft 108. As can be seen in FIGS. 13, 14 and 16, in particular, second compensator sheave 147b diverts second payload cable 106 at substantially 180 degrees relative to the third direction D3. The third direction D3 is parallel to the fourth direction D4 and opposes the fourth direction D4. In the illustrated embodiment, the first, second, third and fourth directions D1, D2, D3, D4 are all parallel with each other and with the longitudinal direction of the axial shaft 108.

[0266] First diverter sheave 146a is aligned in the longitudinal direction of axial shaft 108 with the point of reel 110 at which the first payload cable 104 to be diverted is rolled on and off reel 110 at all times. Similarly, second diverter sheave 146b is aligned in the longitudinal direction of axial shaft 108 with the point of reel 110 at which the second payload cable 106 to be diverted is rolled on and off reel 110 at all times. Hence first diverter sheave 146a of the first diverter mechanism is positioned closer to the front end of the reeling device 102 than second diverter sheave 146b of the second diverter mechanism.

[0267] As reel 110 rotates in use of the reeling device 102, one of the payload cables is rolled on the reel and the other payload cable is rolled off the reel. One of the diverter sheaves 146a, 146b receives the payload cable being rolled off the reel and diverts it by approximately 90 degrees, guiding the payload cable in a forward direction which is substantially parallel to axial shaft 8. Meanwhile, the other diverter sheave 146a, 146b receives the other, paid out payload cable from a direction which is substantially parallel to axial shaft 108 and diverts it by approximately 90 degrees, guiding the payload cable in a rearward direction and then diverting it as it is pulled towards and rolled on the reel. This operation is substantially as described above in relation to the embodiment of FIGS. 1 to 7.

[0268] In contrast to the previous embodiments, each payload cable 104, 106 passes via a compensator sheave 147a, 147b and is diverted by approximately 180 degrees, guiding the payload cable in a direction of the load. Accordingly, in contrast to the previously described embodiments, the payload cables 104, 106 exit the reeling device 102 at its rear end: tension is generated in the rearward direction only. As such, in the embodiment shown in FIGS. 13 to 19, first-direction rollers 114 face generally towards a rear of reeling device 102 in an axial direction (i.e. in a general direction of a tension load applied on the payload cables 104, 106 exiting the reeling device) and second-direction rollers 116 face generally towards a front of the reeling device 102 in an axial direction.

[0269] Provision of compensator sheaves 147a, 147b has been found to significantly reduce (substantially eliminate) the axial load on the first-direction rollers 114. This allows the number of first-direction rollers 114 to be reduced. Additionally, noise generated by first-direction rollers 114 bearing against helical grooves 111 during operation of reeling device 102 is reduced.

[0270] Accordingly, in the illustrated embodiment, only four first-direction rollers 114 are spaced at substantially uniform intervals around nut member 112. Four second-direction rollers 116 are spaced at substantially uniform intervals around nut member 112, however it will be appreciated that alternative embodiments may comprise only three second-direction rollers 116, as for the previous embodiment.

[0271] It will be appreciated that the above benefits of this arrangement are equally applicable to a reeling device provided with only a single payload cable.

[0272] First and second diverter sheaves 146a, 146b are indirectly connected to nut member 112 via a carriage 142. Carriage 142 is arranged for movement in the longitudinal direction of axial shaft 108 along track 144 which is a linear slide track: nut member 112 is connected indirectly to carriage 142.

[0273] Carriage 142 comprises two opposing brackets 142b located on either side of reel 110 and arranged to indirectly connect first and second diverter sheaves 146a, 146b to nut member 112 in the same manner as described above in relation to the embodiment of FIGS. 1 to 7. Accordingly, helical groove 111 has the effect of transporting first and second diverter sheaves 146a, 146b in the longitudinal direction of axial shaft 108.

[0274] Accordingly, as reel 110 rotates, first and second diverter sheaves 146a, 146b move axially along track 144 at the same rate as nut member 112, such that the first and second diverter sheaves 146a, 146b are always in the same position relative to the points at which their respective payload cables roll on and off reel 110.

[0275] First and second compensator sheaves 147a, 147b are rotatably mounted within a compensator carriage 143. Compensator carriage 143 is arranged for movement in the longitudinal direction of axial shaft 108 along track 144.

[0276] Compensator carriage 143 is arranged for concurrent movement with carriage 142 (hereafter ‘diverter carriage’142) in the longitudinal direction of axial shaft 108, such that first and second compensator sheaves 147a, 147b are arranged for concurrent movement with first and second diverter sheaves 146a, 146b.

[0277] Compensator carriage 143 is connected to diverter carriage 142 via a gear mechanism 192 to effect concurrent movement. A gear ratio of gear mechanism 192 is arranged such that a rate of movement of diverter carriage 142 (and thus diverter sheaves 146a, 146b) is greater than a rate of movement of compensator carriage 143 (and thus compensator sheaves 147a, 147b).

[0278] More specifically, a rate of movement of diverter carriage 142 (and thus diverter sheaves 146a, 146b) is two times greater than a rate of movement of compensator carriage 143 (and thus compensator sheaves147a, 147b).

[0279] This is illustrated in FIGS. 18 and 19. FIG. 18 shows reeling device 102 with nut member 112 in a forward position. First payload cable 104 is substantially rolled off reel 110 and second payload cable 106 is substantially rolled on reel 110: nut member 112 is located towards the front of reeling device 102.

[0280] FIG. 19 shows reeling device with nut member 112 in a rearward position. First payload cable 104 substantially rolled on reel 110 and second payload cable 106 substantially rolled off reel 110: nut member 112 is located towards the rear of reeling device 102.

[0281] In FIG. 18, a position of a rotational axis of first compensator sheave 147a in the longitudinal direction is indicated as position X1(A) and a position of a rotational axis of second compensator sheave 147b in the longitudinal direction is indicated as position X1(B). A position of a rotational axis of first diverter sheave 146a in the longitudinal direction is indicated as position Y1(A) and a position of a rotational axis of second diverter sheave 146b in the longitudinal direction is indicated as position Y1(B).

[0282] In FIG. 19, a position of a rotational axis of first compensator sheave 147a in the longitudinal direction is indicated as position X2(A) and a position of a rotational axis of second compensator sheave 147b in the longitudinal direction is indicated as position X2(B). A position of a rotational axis of first diverter sheave 146a in the longitudinal direction is indicated as position Y2(A) and a position of a rotational axis of second diverter sheave 146b in the longitudinal direction is indicated as position Y2(B).

[0283] When the nut member 112 moves from a forward position (FIG. 18) to a rearward position (FIG. 19), a distance travelled by the first compensator sheave 147a is denoted ΔX(A); a distance travelled by the second compensator sheave 147B is denoted ΔX(B); a distance travelled by the first diverter sheave 146A is denoted ΔY(A); and a distance travelled by the second compensator sheave 147B is denoted ΔY(B).

[0284] As can be seen, ΔY(A) is greater than ΔX(A), and ΔY(B) is greater than ΔX(B). Specifically, ΔY(A) is two times greater than ΔX(A), and ΔY(B) is two times greater than ΔX(B).

[0285] With this arrangement, the compensator sheaves 147a, 147b compensate for the change in length of the first and second payload cables 104 and 106 as the nut member 112 (and thus the first and second diverter sheaves 146a, 146b) travels in the longitudinal direction of the axial shaft 108. This ensures that respective ends of the first and second payload cables 104, 106 that are attached to a load are provided in the desired position, despite the change in position along the longitudinal direction of the axial shaft at which the payload cables 104, 106 are rolled on and rolled off the reel 110. Accordingly, the position of the end of the payload cable is determined only by the payload cable being rolled on and off the reel.

[0286] Whilst relative movement of first and second diverter sheaves 146a, 146b and first and second compensator sheaves 147a, 147b is effected by means of gear mechanism 192 in the illustrated embodiment, it will be appreciated that alternative means for effecting the relative movement may be used so as to provide a gearless reeling device.

[0287] One such embodiment is illustrated schematically in FIG. 20, which shows a reeling device 202 comprising a reel 210 and a nut member 212. A single payload cable 204 is shown coiled around reel 210 for clarity, however it will be appreciated that a second payload cable may also be used as for the embodiments previously described.

[0288] A diverter sheave 246 is indirectly connected to nut member 212 via a diverter carriage 242 arranged for movement in the longitudinal direction of an axial shaft (not shown) on which reel 210 is mounted. Carriage 242 moves along a track 244. Diverter sheave 246 diverts payload cable 204 from the reel 210 in a first direction.

[0289] A compensator sheave 247 receives payload cable 204 from diverter sheave 246 and diverts payload cable 204 approximately 180 degrees into a second direction. Compensator sheave 247 is mounted on a compensator carriage 243 that is arranged for concurrent movement with diverter carriage 242 in a longitudinal direction of the axial shaft, along track 244, such that compensator sheave 247 is arranged for concurrent movement with diverter sheave 246.

[0290] Reeling device 202 comprises a cable mechanism 294 for effecting concurrent axial movement of diverter sheave 246 and compensator sheave 247. Cable mechanism 294 comprises a compensator cable 295 having a fixed length, a first sheave 296a (provided on the same rotational axis as compensator sheave 247), a second sheave 296b arranged to receive compensator cable 295 from first sheave 296a and divert compensator cable 295 at approximately 180 degrees, and a third sheave 296c arranged to receive compensator cable 295 from second sheave 296b and divert compensator cable 295 at approximately 180 degrees. A first end 295a of compensator cable 295 is fixed to a chassis 297 that is fixed relative to reel 210 in a longitudinal direction of the axial shaft. A second end 295b of compensator cable 295 is fixed to carriage 242 so as to move with diverter sheave 246 in a longitudinal direction of the axial shaft.

[0291] With this arrangement, movement of nut member 212 in a longitudinal direction of the axial shaft effects a concurrent movement of diverter sheave 246 and compensator sheave 247 in the same direction. Therefore, as payload cable 204 is rolled on and off reel 210, diverter sheave 246 and compensator sheave 247 move concurrently.

[0292] A second position of nut member 212, diverter sheave 246 and compensator sheave 247 is indicated in dashed lines. A distance travelled by compensator sheave 247 is denoted ΔX and a distance travelled by diverter sheave 246 is denoted ΔY.

[0293] A tension of compensator cable 295 is denoted Fc and a tension of payload cable 204 is denoted Fp.

[0294] When the payload cable is in tension:Fc=Fp

[0295] Tension Fp of payload cable 204 acts on diverter sheave 246 (and thus on nut member 212 and rollers mounted thereon) in a first axial direction. Tension Fc of compensator cable 295 acts on nut member 212 (and thus rollers mounted thereon) via carriage 242 in a second axial direction opposing (at 180 degrees relative to) the first axial direction. A sum of the forces acting on diverter sheave 246 (and therefore on rollers mounted on nut member 212) in the longitudinal direction of the axial shaft is:Fc-Fp⁢=0

[0296] Tension Fp of payload cable 204 acts on compensator sheave 247 in the second axial direction. Tension Fc of compensator cable 295 acts compensator sheave 247 in the first axial direction. A sum of the forces acting on compensator sheave 247 in the longitudinal direction of the axial shaft is:2·Fc-2·Fp⁢=0

[0297] Thus, an axial load acting on the or each roller mounted on the nut member 212 in the longitudinal direction of the axial shaft resulting from tension of said payload cable is zero. At the same time, the distance ΔX travelled by compensator sheave 247 is half the distance ΔY travelled by diverter sheave 246 (that is, ΔY is two times greater than ΔX).

[0298] It will be appreciated that further alternative arrangements for effecting concurrent movement of the diverter sheave and compensator sheave may be employed, wherein the resultant axial load on the nut member and rollers is zero, and the rate of movement of the diverter sheave is two times greater than the rate of movement of the compensator sheave. Such mechanisms may include lever mechanisms or hydraulic / fluid-powered mechanisms.

[0299] 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.

Examples

Embodiment Construction

[0157]Referring to FIGS. 1 to 7, a reeling device 2 in accordance with one aspect of the present invention is shown. The reeling device 2 is a winch for the controlled coiling and uncoiling of two payload cables being a first payload cable 4 and a second payload cable 6.

[0158]The reeling device 2 comprises an axial shaft 8, a reel 10 mounted on axial shaft 8, a nut member 12 which is a travelling nut and a plurality of first-direction rollers 14 and a plurality of second-direction rollers 16 mounted on nut member 12.

[0159]Reel 10 has an outer surface about which a length of first payload cable 4 and a length of second payload cable 6 are coiled in use.

[0160]Nut member 12 substantially surrounds reel 10 and is radially spaced from the outer surface of reel 10.

[0161]The outer surface of reel 10 is provided with a helical groove 11 (see FIG. 9) for receiving first payload cable 4, second payload cable 6, first-direction rollers 14 and second-direction rollers 16. In use, these rollers ...

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a 35 U.S.C. § 371 national phase filing of International Application No. PCT / GB2023 / 053290 filed on Dec. 18, 2023 and claims the benefit of United Kingdom Patent Application No. 2219031.8 filed on Dec. 16, 2022, wherein the entire disclosures of the foregoing applications are hereby incorporated by reference herein.TECHNICAL FIELD

[0002] The present invention relates to a reeling device for the controlled coiling and uncoiling of a payload cable.

[0003] Reeling devices such as winches may be used in the entertainment industry. They are designed to raise and lower a load connected to an end of a cable. For example, they are designed to lift and lower microphone cables, scenery or flying performers. Reeling devices may also be designed to slide scenery forwards and backwards across a stage in a horizontal direction, for example. Suitable payload cables are ropes and cables (including fibre-optic cables).

[0004] For supporting flying performers, it is particularly important that the reeling devices used are robust, strong and safe: they should be able to operate at high speeds, operate quietly and be sufficiently compact to fit in restricted spaces.

[0005] WO 2021 / 099800 A1 discloses an earlier invention from the present inventor. The reeling device disclosed comprises first and second reels about which a 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.

[0006] The present invention seeks to provide a different reeling device for the controlled coiling and uncoiling of a payload cable.SUMMARY

[0007] According to a first aspect of the present invention, there is provided a reeling device for the controlled coiling and uncoiling of a payload cable, the reeling device comprising an axial shaft and a reel mounted on the axial shaft for rotation about the axial shaft, a nut member and at least one roller mounted on the nut member, wherein

[0008] the reel has an outer surface about which a length of cable is adapted to be wrapped,

[0009] the nut member substantially surrounds the reel and is radially spaced from the outer surface of the reel,

[0010] the outer surface of the reel is provided with a helical groove for receiving one or more payload cables, and

[0011] the or each roller is adapted to rotate while engaging the helical groove,

[0012] the reeling device further comprising:

[0013] a diverter sheave directly or indirectly connected to the nut member and arranged to receive a payload cable from the reel and divert the payload cable in a first direction, and

[0014] a compensator sheave arranged to receive said payload cable from the diverter sheave and divert the payload cable in a second direction different to the first direction,

[0015] wherein the diverter sheave and compensator sheave are arranged for concurrent movement in the longitudinal direction of the axial shaft.

[0016] With the arrangement of the present invention, the diverter sheave can be aligned with the position at which the payload cable rolls on and off the reel in the longitudinal direction of the axial shaft. At the same time, the compensator sheave diverts the payload cable in a second direction for attachment of the payload cable to a load. Provision of a compensator sheave arranged according to the present invention has been found to significantly reduce the axial load acting on the roller. This results in less noise being generated by the roller bearing against the outer surface of the reel, improved efficiency of the reeling device and greater longevity of the device components (in particular, the roller). Additionally, the number of rollers required can be minimised without a loss in performance or load-bearing capacity of the reeling device.

[0017] In an embodiment where a bearing is provided for the roller, an axial load on the bearing is also beneficially reduced.

[0018] Preferably, the first direction and second direction are arranged such that, in use, when a payload cable is received by the reel, diverter sheave and compensator sheave and is in tension, an axial load acting on the or each roller in the longitudinal direction of the axial shaft resulting from tension of said payload cable is substantially zero. That is, the geometry of the payload cable(s) as determined by the diverter sheave and compensator sheave is preferably such that the cable tensions resolve to provide no (zero) resultant axial load on the nut member and, consequently, the or each roller. (The axial load will be zero except for a minimal horizontal component of the tension in the short section of cable between the reel and diverter, should the cable approach the reel at an angle other than 90 degrees to the reel axis. The cable may approach at the reel helix angle rather than exactly 90 degrees). This arrangement significantly reduces noise generated by the roller and nut member and improves the longevity of the roller. It will be appreciated that various different arrangements of the diverter sheave and compensator sheave are possible that are suitable for providing a zero axial load on the nut member and the or each roller. The exact arrangement may depend on factors such as, for example, the mechanism used to effect concurrent movement of the diverter sheave and compensator sheave and the angle at which the payload cable is diverted from the reel by the diverter sheave.

[0019] A rate of movement of the diverter sheave in a longitudinal direction of the axial shaft may be greater than a rate of movement of the compensator sheave in the longitudinal direction of the axial shaft during concurrent movement of the diverter sheave and the compensator sheave. Accordingly, a distance travelled by the diverter sheave in a longitudinal direction of the axial shaft is greater than a distance travelled by the compensator sheave in the longitudinal direction of the axial shaft. As the diverter sheave travels in the longitudinal direction of the axial shaft, the position at which the payload cable rolls on and off the reel changes. Therefore, the effective length of the payload cable will also change. With the above arrangement, the compensator sheave is able to at least partially compensate for this change in length of the payload cable as the diverter sheave travels in the longitudinal direction of the axial shaft.

[0020] Preferably, the rate of movement of the diverter sheave in a longitudinal direction of the axial shaft is two times greater than the rate of movement of the compensator sheave in the longitudinal direction of the axial shaft during concurrent movement of the diverter sheave and compensator sheave. Accordingly, a distance travelled by the diverter sheave in a longitudinal direction of the axial shaft is two times greater than a distance travelled by the compensator sheave in the longitudinal direction of the axial shaft. With this arrangement, the compensator sheave fully compensates for the change in effective length of the payload cable as the diverter sheave travels in the longitudinal direction of the axial shaft. The position of a load attached to an end of the payload cable is therefore independent of the position of the diverter sheave relative to the reel, and can be controlled by coiling and uncoiling of the payload cable from the reel. Thus, the position of a load on the end of a cable is solely determined by the rotation of the reel and is independent of the rotational direction in which the cable is wound onto the reel (i.e. clockwise or counter-clockwise).

[0021] The first direction may be parallel to the second direction. That is, the second direction may be arranged at approximately 180 degrees relative to the first direction. In such embodiments, the compensator sheave is arranged to divert the payload cable at an angle of approximately 180 degrees relative to the first direction. The first direction and / or the second direction may be parallel to the longitudinal direction of the axial shaft. In particularly preferred embodiments, the diverter sheave is arranged to receive the payload cable from the reel in a direction approximately perpendicular (i.e. perpendicular or near perpendicular) to the longitudinal direction of the axial shaft and to divert the payload cable approximately 90 degrees into the first direction that is parallel to the longitudinal direction of the axial shaft, and the compensator sheave is arranged to divert the payload cable approximately 180 degrees into the second direction.

[0022] The nut member may be mounted for movement in the longitudinal direction of the axial shaft and fixed against rotation about the axial shaft.

[0023] The diverter sheave may be directly or indirectly connected to the nut member to move with the nut member in a longitudinal direction of the axial shaft. Movement of the diverter sheave in the longitudinal direction of the axial shaft may be fixed relative to movement of the nut member in the longitudinal direction of the axial shaft. That is to say, the diverter sheave is arranged to move with the nut member at the same rate of movement.

[0024] The reeling device further may comprise a carriage which is arranged for movement in the longitudinal direction of the axial shaft and at least one of the nut member and the first diverter sheave is directly or indirectly connected to the carriage.

[0025] According to a second aspect of the present invention there is provided a reeling device for the controlled coiling and uncoiling of a payload cable, the reeling device comprising an axial shaft, a reel mounted on the axial shaft, a nut member and at least one roller mounted on the nut member, wherein

[0026] the reel has an outer surface about which a length of cable is adapted to be wrapped,

[0027] the nut member substantially surrounds the reel and is radially spaced from the outer surface of the reel,

[0028] the outer surface of the reel is provided with a helical groove for receiving one or more cables,

[0029] the or each roller is adapted to rotate while engaging the helical groove, and

[0030] the or each roller has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

[0031] In this aspect of the present invention, the radial plane of the roller passes through the distal end of a rim of the roller. A tangent at the distal end of the rim is parallel to the rotational axis of the roller.

[0032] The roller has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft in all radial directions.

[0033] Since the radial plane of the roller is inclined as described above, the load path is inclined and an axial load on the roller is beneficially reduced. Also, a radial component is added to all the forces acting on the roller.

[0034] In an embodiment where a bearing is provided for the roller, the load path is inclined and an axial load on the bearing is beneficially reduced. Also, a radial component is added to all the forces acting on the bearing.

[0035] As a result of the second aspect of the present invention, force is better directed over the roller as opposed to a case where the radial plane of the roller is perpendicular to the longitudinal direction of the axial shaft.

[0036] Also, since the radial plane of the roller is inclined, the roller is subjected to a rocking moment which acts to bring the roller in closer contact with the groove on the reel. This means that, should the roller rock in use, it will grip the groove tighter rather than pulling away from the groove.

[0037] The roller may be a tracking roller.

[0038] The reel may be directly or indirectly mounted on the axial shaft. The reel is preferably substantially cylindrical in shape. The reel may be metal or plastic or a composite material. For example, it may be steel or aluminium. In some embodiments, it is anodised aluminium or zinc-plated steel.

[0039] The reeling device may comprise more than one reel and the reels may be provided on the same axial shaft or they may be provided on separate axial shafts of the reeling device: the separate axial shafts may have their axes aligned.

[0040] In one embodiment, the reel has an outer surface about which the lengths of two cables are adapted to be wrapped. In use of the reeling device, the nut member may be located between the respective lengths of the two cables.

[0041] If the reeling device comprises two reels, a first reel may have an outer surface about which a length of at least a first cable is adapted to be wrapped and a second reel may have an outer surface about which a length of at least a second cable is adapted to be wrapped.

[0042] In use of the reeling device, a portion of the or each cable is preferably fixedly connected to the reeling device.

[0043] A first end of the cable may be fixed to the reeling device to allow a stationary connection to be made, for example when the cable is being used to carry signals or power. Alternatively, the first end of the cable may be attached to the reel, for example when the cable is used in a reeling device designed for ‘pure-lifting’. The cable may support any suitable object at an opposing second end.

[0044] The cable may be a synthetic rope or a wire rope or a metal rope or an electric cable or a fibre-optic cable, for example. A suitable synthetic rope is made of polyester. A suitable wire or metal rope is made of steel. These are non-limiting examples of suitable materials for the cable.

[0045] In use of the reeling device, the or each cable is preferably helically coiled about the outer surface of the reel in a single layer, i.e., without overlap in a direction perpendicular to the longitudinal direction of the axial shaft.

[0046] In one embodiment, the roller is adapted to rotate while engaging the helical groove at a point which has already been vacated by a cable: hence the roller is present where the cable is absent: the roller and the cable share the helical groove rather than having mutually exclusive helical grooves.

[0047] The helical groove preferably has a base portion in the form of an arc. In this regard, the base portion of the helical groove is to be understood as the innermost portion of the helical groove that lies closest to the axial shaft.

[0048] The components of the reeling device may be supported by a frame. The frame may be elongate in the longitudinal direction of the axial shaft.

[0049] The nut member may be a single, unitary member.

[0050] More than one nut member may substantially surround the or each reel.

[0051] The reeling device may therefore comprise another nut member which substantially surrounds the reel.

[0052] The nut member may be metal or plastic or a composite material. For example, it may be steel or aluminium.

[0053] In one embodiment, at least one roller is mounted on the nut member and faces generally towards a first end of the reeling device in an axial direction to provide a first-direction roller and at least one other roller is mounted on the nut member and faces generally towards an opposing second end of the reeling device in an axial direction to provide a second-direction roller. The first-direction roller may be a tension roller, which may be effective to resolve a payload tension in the cable. The second-direction roller may be a retract roller, which may be effective when there is no tension in the cable or when the reeling device is used without a cable attached.

[0054] In one embodiment, the first end of the reeling device is a front end of the reeling device and the second end of the reeling device is a rear end of the reeling device, such that the first-direction roller faces generally towards a front of the reeling device in an axial direction and the second-direction roller faces generally towards a rear of the reeling device in an axial direction. The front end of the reeling device may face in the direction in which a payload cable is adapted to be rolled on and off the reeling device.

[0055] In one embodiment, the nut member is substantially annular in shape and has a first annular face and an opposing second annular face, wherein the first annular face is positioned facing the first end (e.g., front end) of the reeling device and the second annular face is positioned facing the second end (e.g., rear end) of the reeling device: at least one tension roller is generally mounted on the first annular face and at least one retract roller is generally mounted on the second annular face.

[0056] The first annular face and / or the second annular face may not form a complete ring-shape as one or more arc-shaped spaces may be provided in the shape of the annular face.

[0057] A series of first-direction (tension) rollers may be provided, preferably spaced at substantially uniform intervals around the first annular face of the nut member.

[0058] A series of second direction (retract) rollers may be provided, preferably spaced at substantially uniform intervals around the second annular face of the nut member.

[0059] The nut member may comprise a plurality of nut member parts. For example, a plurality of substantially annular-shaped nut member parts may be arranged co-axially; or the nut member parts may be arc-shaped and together form a substantially annular shape. It is preferred that each nut member part has at least one roller mounted thereon but this is not essential.

[0060] In an embodiment where the nut member is provided by a plurality of nut member parts, one nut member part may provide the first annular face and another nut part member part may provide the second annular face.

[0061] The or each first-direction (tension) roller may have a radial plane which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in a first (e.g., forward) direction relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

[0062] The or each first-direction (tension) roller may have a radial plane which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in a first (e.g., forward) direction relative to the longitudinal direction of the axial shaft.

[0063] The or each second-direction (retract) roller may have a radial plane which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in an opposing second (e.g., rearward) direction relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

[0064] The or each second-direction (retract) roller may have a radial plane which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in an opposing second (e.g., rearward) direction relative to the longitudinal direction of the axial shaft.

[0065] In one embodiment, the radial plane of the or each first-direction roller and the radial plane of the or each second-direction roller are inclined at the same angle but in opposite directions relative to a plane which is perpendicular to the longitudinal direction of the axial shaft. This arrangement is preferred but optional.

[0066] In one embodiment, there is a greater number of first-direction (tension) rollers mounted on the nut member than there is second-direction (retract) rollers mounted on the nut member.

[0067] Alternatively, the number of first-direction (tension) rollers mounted on the nut member is the same as or smaller than the number of second-direction (retract) rollers mounted on the nut member.

[0068] The number of first-direction (tension) rollers mounted on the nut member may be in the range of 2 to 100, preferably 4 to 64 and more preferably 4 to 32. When a larger number of first-direction (tension) rollers are used, the reel may have a relatively large diameter and accommodate a relatively small diameter cable in the helical groove. In one embodiment, eight first-direction (tension) rollers are mounted on the nut member.

[0069] The number of second-direction (retract) rollers mounted on the nut member may be in the range of 1 to 50, preferably 2 to 32 and more preferably 2 to 16. When a larger number of second-direction (retract) rollers are used, the reel may have a relatively large diameter and accommodate a relatively small diameter cable in the helical groove. In one embodiment, three second-direction (retract) rollers are mounted on the nut member.

[0070] In one embodiment, the reel is mounted for rotation about the axial shaft. Upon rotation of the reel in one direction (e.g., clockwise direction), a cable is rolled on the reel. Upon rotation of the reel in an opposite direction (e.g., an anti-clockwise direction), a cable is rolled off the reel.

[0071] In use of the reeling device, at least one cable is wrapped around an outer surface of the reel. For example, one cable is wrapped around an outer surface of the reel or two cables may be wrapped around an outer surface of the reel.

[0072] In one embodiment, when the reel is mounted for rotation about the axial shaft and two cables are wrapped around an outer surface of the reel in use, upon rotation of the reel in one direction, a first cable is rolled on the reel and a second cable is rolled off the reel and, upon rotation of the reel in an opposite direction, the first cable is rolled off the reel and the second cable is rolled on the reel.

[0073] The first cable may be an outward line and the second cable may be a return line.

[0074] In another embodiment, when the reel is mounted for rotation about the axial shaft and five cables are wrapped around an outer surface of the reel in use, upon rotation of the reel in one direction, first to fourth cables are rolled off the reel and a fifth cable is rolled on the reel and, upon rotation of the reel in an opposite direction, the first to fourth cables are rolled on the reel and the fifth cable is rolled off the reel.

[0075] The first to fourth cables may be outward lines and the fifth cable may be a return line. Alternatively, the first to fourth cables may be return lines and the fifth cable may be an outward line.

[0076] In a further embodiment, when the reel is mounted for rotation about the axial shaft and five cables are wrapped around an outer surface of the reel in use, upon rotation of the reel in one direction, first to third cables are rolled off the reel and fourth and fifth cables are rolled on the reel and, upon rotation of the reel in an opposite direction, the first to third cables are rolled on the reel and the fourth and fifth cables are rolled off the reel.

[0077] The first to third cables may be outward lines and the fourth and fifth cables may be return lines. Alternatively, the first to third cables may be return lines and the fourth and fifth cables may be outward lines.

[0078] In yet another embodiment, the number of return lines equals the number of outward lines. For example, there may be one outward line and one return line or two outward lines and two return lines.

[0079] The invention is not limited to the number of cables to be wrapped around an outer surface of the reel in use of the reeling device.

[0080] The reel may be fixed against movement in the longitudinal direction of the axial shaft or may be mounted for movement in the longitudinal direction of the axial shaft.

[0081] In one embodiment, the reel is fixed against movement in the longitudinal direction of the axial shaft.

[0082] The reeling device may comprise an additional reel and optionally an additional nut member which substantially surrounds the additional reel.

[0083] The additional reel may be mounted on the axial shaft or mounted on another axial shaft.

[0084] More than one reel may be mounted on the axial shaft and / or on another axial shaft. For example, one or more reels are mounted on the axial shaft and one or more reels are mounted on another axial shaft.

[0085] If the reeling device comprises two or more reels, one reel may be fixed against movement in the longitudinal direction of the axial shaft and the other reel may be mounted for movement in the longitudinal direction of the axial shaft; or two reels may be fixed against movement in the longitudinal direction of the axial shaft; or two reels may be mounted for movement in the longitudinal direction of the axial shaft.

[0086] If the reeling device comprises two or more reels, one reel may be fixed against rotation about the axial shaft and the other reel may be mounted for rotation about the axial shaft; or two reels may be mounted for rotation about the axial shaft.

[0087] In one embodiment, the reeling device comprises first and second reels which are coaxial and the first reel is fixed against rotation and axial movement and the second reel is mounted for rotation about the axial shaft with such rotation causing axial movement of the second reel relative to the first reel. One reel or both reels may be substantially surrounded by at least one nut member.

[0088] In one embodiment, the nut member is mounted for movement in the longitudinal direction of the axial shaft and is fixed against rotation about the axial shaft.

[0089] The or each roller may be mounted for rotation about a connector, wherein the connector is directly or indirectly connected to the nut member. The connector is preferably fixed against rotation. The connector may be elongate. The connector may have a shaft.

[0090] An axis of the connector for the roller is preferably inclined relative to the longitudinal direction of the axial shaft of the reeling device.

[0091] In use of the reeling device, the roller rotates about the connector while engaging the helical groove. The rollers are urged to rotate by frictional contact with the helical groove.

[0092] The or each roller may comprise a rim, wherein the rim is adapted to engage the helical groove on the outer surface of the reel.

[0093] In use of the reeling device, the roller may engage the helical groove at a point which is located between a first cable wrapped about the reel and a second cable wrapped about the reel.

[0094] A rolling-element bearing may be provided to enable the roller to rotate. This bearing may be annular in shape.

[0095] The bearing may be located between the connector and the roller.

[0096] In one embodiment, the bearing comprises a plurality of balls or rollers, an inner race and an outer race, between which races the balls or rollers are adapted to run.

[0097] The inner race is adapted to be stationary in use and is directly or indirectly connected to the connector. In this regard, at least one bush may be provided to clamp the inner race. The or each bush may be located between the connector and the bearing.

[0098] The outer race is directly or indirectly connected to the roller and is adapted to rotate therewith. As the outer race rotates in use it causes the balls or rollers to rotate.

[0099] The or each roller may comprise an annular body. A tyre may be fitted to the annular body. If so, the rim of the roller may comprise the tyre.

[0100] The bearing may be located radially inward of the annular body.

[0101] In an embodiment where the roller comprises a bearing, the inclination of the roller acts to reduce the load on the bearing such that the roller operates without overloading the bearing.

[0102] The or each roller may include a base mounted directly or indirectly on the connector, a distal end opposite the base and a pair of sidewalls extending between the base and the distal end: the distal end engages the groove.

[0103] In one embodiment, the reeling device further comprises a carriage which is arranged for movement in the longitudinal direction of the axial shaft and the nut member is directly or indirectly connected to the carriage. The nut member is preferably indirectly connected to the carriage. The nut member may act to hold the carriage in place during use of the reeling device.

[0104] The nut member may be indirectly connected to the carriage via a bearing. In one example, the nut member is indirectly connected to the carriage by a bearing and torque arm arrangement: the bearing may be one or more spherical rod end bearings: one or more torque arms may interconnect the bearing and the nut member: the bearing may be directly or indirectly connected to the carriage.

[0105] The carriage may be provided with at least one diverter sheave for a cable. The diverter sheave may be adapted to deflect the cable to guide it substantially in the longitudinal direction of the axial shaft or to guide it in a direction substantially perpendicular to the longitudinal direction of the axial shaft onto the reel. The diverter sheave may be mounted for rotation about a transverse axis which extends across the width of the reeling device.

[0106] Rotation of the reel in use of the reeling device causes the roller(s) mounted on the nut member to travel in the helical groove: simultaneously, a payload cable is rolled on or off the helical groove via the diverter sheave and this effects rotation of the diverter sheave and thus linear movement of the carriage in the longitudinal direction of the axial shaft. The helical grooves have the effect of transporting the diverter sheave rather than the reel in the longitudinal direction of the axial shaft.

[0107] The diverter sheave is preferably a pulley which is mounted for rotation with its radial plane being substantially parallel to the longitudinal direction of the axial shaft.

[0108] In one embodiment, the carriage is provided with one diverter sheave per cable coiled and uncoiled by the reeling device.

[0109] In an embodiment where five cables are wrapped around an outer surface of the reel in use, five diverter sheaves are provided.

[0110] An outward diverter sheave is provided for the or each outward cable and a return diverter sheave is provided for the or each return cable.

[0111] If the reeling device is adapted to coil and uncoil a single cable, a single diverter sheave may be provided.

[0112] The carriage may comprise two opposing brackets which are preferably located on either side of the reel, these brackets opposing each other in a direction which is substantially transverse to the longitudinal direction of the axial shaft. The nut member may be positioned between the brackets of the carriage such that a radial plane of the nut member lies in a direction which is substantially transverse to the longitudinal direction of the axial shaft.

[0113] One or each bracket of the carriage may be provided with at least one diverter sheave for a cable, depending on the number of cables to be used.

[0114] In use of an embodiment of the reeling device, the bracket transmits force from the diverter sheave onto the nut member (either directly or indirectly) and therefore assists in resolving axial tension in the cable.

[0115] Preferably, when there is one or more outward cable and one or more return cable, the or each outward diverter sheave is provided on one bracket and the or each return diverter sheave is provided on the other bracket.

[0116] In one embodiment, a plurality of diverter sheaves is provided on a bracket: the diverter sheaves are spaced in the longitudinal direction of the axial shaft and spaced in correspondence with the relevant number of pitches of the helical groove on the reel: the bracket is extended in length in the longitudinal direction of the axial shaft to accommodate the diverter sheaves accordingly.

[0117] A plurality of diverter sheaves provided on a common bracket may be associated with a common nut member. Alternatively, each of a plurality of diverter sheaves provided on a common bracket may be associated with a corresponding separate nut member.

[0118] In another embodiment, each of a plurality of diverter sheaves are provided on a separate bracket and associated with a corresponding separate nut member, meaning that the number of diverter sheaves corresponds to the number of brackets and to the number of nut members.

[0119] The diverter sheave is preferably aligned in the longitudinal direction of the axial shaft with the point of the reel at which the cable is rolled on and off the reel at all times.

[0120] The reeling device of the present invention is preferably a ‘zero fleet’ reeling device. Such a reeling device is designed, along with any additional guiding means such as further diverter sheaves or guide wheels, such that the radial and axial location and the orientation of a portion of a cable does not change during reeling and unreeling of the cable. This provides the ability to locate the reeling device directly over a hole in an auditorium ceiling, for example.

[0121] The helical groove of the reel may be the source of a zero-fleet mechanism.

[0122] The or each payload cable is preferably unbroken between its first and second ends. The or each payload cable is preferably circular in cross-section.

[0123] The reeling device may comprise a carriage nut which is coaxial with the nut member. The carriage nut may be radially spaced from the outer surface of the reel. A bearing surface may be provided between the carriage nut and the nut member.

[0124] In one embodiment, the carriage nut is mounted between and connected to each bracket of the carriage at a connection point which comprises a bearing.

[0125] A motor for the reeling device may be located within the reel. Alternatively, a motor for the reeling device may located externally of the reel.

[0126] The reeling device may comprise a gearbox for the motor.

[0127] The reeling device may be a winch. It may be a direct drive winch.

[0128] The reel may be a drum. The helical groove may be a drum scroll.

[0129] The helical groove may have a multiple-start helix configuration.

[0130] One or more brakes may be provided, particularly where the axial shaft is driven by a motor.

[0131] Preferably, no separate lead screw is required to effect longitudinal movement of the carriage in the reeling device of the present invention.

[0132] A controller may be provided for controlled-motion coiling and uncoiling of the cables when raising or lowering an object.

[0133] Any of the features or embodiments described above in relation to the second aspect of the invention may be combined with the features or embodiments described above in relation to the first aspect of the present invention and vice versa. For example, the reeling device in accordance with the first aspect may be provided with one or more rollers having a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft, as described above in relation to the second aspect of the invention. It will be further appreciated that advantages and benefits of any features described above in relation to one aspect of the invention will be equally applicable where that same feature is incorporated into the other aspect of the present invention.

[0134] The present invention also provides a method of coiling and uncoiling at least one cable on a reel of the reeling device described above in relation to one or both of the first and second aspects of the present invention. In one embodiment, the method comprises coiling and uncoiling two cables on the same reel.

[0135] Further, the present invention provides the use of a reeling device described above in relation to one or both of the first and second aspects of the present invention to coil and uncoil at least one cable.BRIEF DESCRIPTION OF DRAWINGS

[0136] Non-limiting embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0137] FIG. 1 is a front perspective view of a reeling device according to an embodiment of the present invention with a nut member in a rearward position;

[0138] FIG. 2 is a front perspective view of the reeling device of FIG. 1 with the nut member in a forward position;

[0139] FIG. 3 is top plan view of the reeling device of FIG. 1;

[0140] FIG. 4 is a side view of the reeling device of FIG. 1;

[0141] FIG. 5 is a longitudinal sectional view of the reeling device of FIG. 1 from one side;

[0142] FIG. 6 is a longitudinal sectional view of the reeling device of FIG. 1 from another side;

[0143] FIG. 7 is a transverse sectional view of the reeling device along line X-X of FIG. 3, looking towards a front end of the reeling device;

[0144] FIG. 8 is a rear perspective view of the nut member;

[0145] FIG. 9 is a longitudinal sectional enlarged view of part of the reeling device of FIG. 1 showing a roller;

[0146] FIG. 10 is a cross-sectional view of the body of the roller;

[0147] FIGS. 11a and 11b are perspective and front views of the roller, respectively;

[0148] FIGS. 12a to 12c are front, side and perspective views of the roller mounted on a connector, respectively;

[0149] FIG. 13 is a front perspective view of a reeling device according to a further embodiment of the present invention, with a nut member in a rearward position;

[0150] FIG. 14 is a rear perspective view of the reeling device of FIG. 13, with the nut member in a rearward position; viewed from the opposing end of the reeling device to FIG. 13.

[0151] FIG. 15 is a rear perspective view of the reeling device of FIGS. 13 and 14, with the nut member in a forward position;

[0152] FIG. 16 is a further rear perspective view of the of the reeling device of FIGS. 13 and 14, with the nut member in a forward position, viewed from the opposing side of the reeling device to FIG. 15;

[0153] FIG. 17 is a longitudinal sectional view of the reeling device of FIG. 13 from one side, with the nut member in a forward position;

[0154] FIG. 18 is a side view of the reeling device of FIG. 13, with the nut member in a forward position;

[0155] FIG. 19 is a side view of the reeling device of FIG. 13, with the nut member in a rearward position, and

[0156] FIG. 20 is a schematic view of a reeling device in accordance with a further aspect of the present invention.DETAILED DESCRIPTION

[0157] Referring to FIGS. 1 to 7, a reeling device 2 in accordance with one aspect of the present invention is shown. The reeling device 2 is a winch for the controlled coiling and uncoiling of two payload cables being a first payload cable 4 and a second payload cable 6.

[0158] The reeling device 2 comprises an axial shaft 8, a reel 10 mounted on axial shaft 8, a nut member 12 which is a travelling nut and a plurality of first-direction rollers 14 and a plurality of second-direction rollers 16 mounted on nut member 12.

[0159] Reel 10 has an outer surface about which a length of first payload cable 4 and a length of second payload cable 6 are coiled in use.

[0160] Nut member 12 substantially surrounds reel 10 and is radially spaced from the outer surface of reel 10.

[0161] The outer surface of reel 10 is provided with a helical groove 11 (see FIG. 9) for receiving first payload cable 4, second payload cable 6, first-direction rollers 14 and second-direction rollers 16. In use, these rollers engage the helical groove in a space between the payload cables.

[0162] First-direction rollers 14 and second-direction rollers 16 are adapted to rotate while engaging the helical groove. Rotation of these rollers effects axial movement of nut member 12.

[0163] Nut member 12 travels in the longitudinal direction of axial shaft 8 as the payload cables are paid out and pulled in from the reeling device.

[0164] Each first-direction roller 14 and second-direction roller 16 has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8.

[0165] In this embodiment, reel 10 is a cylindrical drum and helical groove 11 is a drum scroll.

[0166] In use of the reeling device, nut member 12 is located between the respective lengths of the two payload cables 4 and 6.

[0167] In use of the reeling device, a portion of each payload cable is connected and fixed to the reeling device. Referring to FIG. 4, an end portion of first payload cable 4 is connected and fixed at termination point 18 and an end portion of second payload cable 6 is connected and fixed at termination point 20. Termination point 18 is located at or towards the front end of reel 10 and termination point 20 is located at or towards the rear end of reel 10. Depending on the material of the payload cables, one or more standing turns of each payload cable on reel 10 may be provided at each termination point to provide additional friction.

[0168] Each payload cable is adapted to support a load at an opposing free end portion.

[0169] In use of the reeling device, as shown in the figures, each payload cable is helically coiled about the outer surface of reel 10 in a single layer, meaning that there is no overlap in a direction perpendicular to the longitudinal direction of axial shaft 8.

[0170] In this embodiment, the diameter of each payload cable is 6 mm and the reel pitch is 6.5 mm. Alternative payload cable diameters and pitches are possible.

[0171] As shown in FIGS. 1 to 8, first-direction rollers 14 face generally towards a front of the reeling device in an axial direction and second-direction rollers 16 face generally towards a rear of the reeling device in an axial direction. In use, first-direction rollers 14 are effective to resolve a payload tension in the cable. This is because both cables exit the reeling device at its front end and therefore generate tension in this direction only. Accordingly, first-direction rollers 14 are also referred to as tension rollers 14 in the following description of this embodiment of the present invention. Second-direction rollers 16 are effective when there is no tension in the cable or when the reeling device is used without a cable attached. Accordingly, second-direction rollers 16 are also referred to as ‘retract rollers’16 in the following description of this embodiment of the present invention.

[0172] Alternative arrangements are possible where tension could be generated in either of the opposing directions, in which case the second-direction (retract) rollers would function as tension rollers when the net sum of cable tensions results in a rearwards force.

[0173] The front end of the reeling device faces in the forward direction in which the payload cables are adapted to be rolled in and rolled off the reeling device.

[0174] First payload cable 4 is coiled around the portion of reel 10 between nut member 12 and the front end of the reel 10. Second payload cable 6 is coiled around the portion of reel 10 between nut member 12 and the rear end of the reel 10. Both payload cables are wound helically on reel 10, fitting within helical groove 11 on the outer surface of the reel.

[0175] Reel 10 is mounted for rotation about axial shaft 8. Upon rotation of the reel in one direction, first payload cable 4 is rolled on the reel and second payload cable 6 is rolled off the reel and, upon rotation of the reel in an opposite direction, first payload cable 4 is rolled off the reel and second payload cable 6 is rolled on the reel.

[0176] The first payload cable may be an outward line and the second payload cable may be a return line.

[0177] When the reeling device is used in a horizontal orientation, meaning that the longitudinal direction of the axial shaft extends substantially horizontally, the use of first and second payload cables as described above is useful for translational motion of an object.

[0178] In one example, two reeling devices 2 are mounted in opposite wings of a stage. The free end portions of first payload cable 4 and second payload cable 6 of a first reeling device are attached to one side of an item of scenery or a prop item and the free end portions of first payload cable 4 and second payload cable 6 of a second reeling device are attached to an opposite side of the item of scenery or the prop item.

[0179] As the respective payload cables are paid out and pulled in by the reeling devices, the item of scenery or the prop item can be pulled onto the stage and subsequently pulled off the stage, preferably in a sliding motion. The above arrangement may also be accomplished with a non-horizontal shaft by use of intermediate diverter sheaves for the ropes / cables such that the intermediate sheaves direct the cables / ropes in the required direction.

[0180] In another example, a reeling device 2 is mounted in each of three or more spaced locations above a stage. Typically, the reeling devices are not mounted in a straight line, although this is possible when a simple up-down motion is required. In this example, the devices may be equipped with a single cable and the free end portion of payload cable 4 of each reeling device is attached to attachment points on a harness of a performer or on an item of scenery.

[0181] As the respective payload cables are paid out and pulled in by the reeling devices, the performer or item of scenery is lifted above the stage and moved around in space to fly. This is known as ‘3D flying’ where, due to the layout of the devices in space, the item can be lifted vertically and traversed horizontally.

[0182] The reeling device may be provided with a single payload cable, for example for horizontal translational motion of an object. The nut member may be located forward or rearward of the cable. Bi-directional horizontal translation may be effected by using two payload cables being an outward line and a retract line.

[0183] The reeling device may also be used in a vertical orientation, meaning that the longitudinal direction of the axial shaft extends substantially vertically.

[0184] The payload cable or cables may extend vertically downwards from the reeling device in this orientation to provide a zero-fleet arrangement directly. If the reeling device is oriented vertically and mounted above a ceiling of a stage, for example, the payload cable or cables may drop through a hole in the ceiling to vertically raise and lower a microphone cable or a prop item, for example.

[0185] With reference to FIGS. 5 and 6, an electro-magnetic motor 17 for the reeling device is located substantially within the reel. This contributes to providing a compact design for the reeling device.

[0186] When there is restricted space to accommodate a reeling device, for example above a stage, the compact design of the reeling device is useful.

[0187] The reeling device is gearless in this embodiment: rotation of the axial shaft effects rotation of the reel without the need for a gear set to transfer rotational or axial movement between the components.

[0188] In other embodiments, the reeling device comprises a gear: for example, a gear set may be used to synchronise two reels. Alternatively, a gearbox may be used to connect an external motor to the shaft.

[0189] In this embodiment, reel 10 is mounted for rotation about axial shaft 8 and fixed against movement in the longitudinal direction of axial shaft 8. Nut member 12 is mounted for movement in the longitudinal direction of axial shaft 8 and is fixed against rotation about axial shaft 8.

[0190] Referring to FIG. 8, nut member 12 is substantially annular in shape and has a first annular face 21 and an opposing second annular face 22, wherein first annular face 21 is positioned facing the front end of the reeling device and second annular face 22 is positioned facing the rear end of the reeling device.

[0191] In this embodiment, nut member 12 is an annular ring which surrounds reel 10. Nut member 12 has an inner diameter which is greater than the outer diameter of reel 10, such that nut member 12 is radially spaced from the outer surface of reel 10.

[0192] In this embodiment, first annular face 21 and second annular face 22 form a complete ring-shape but this is not essential: for example, one or more arc-shaped spaces may be provided in the shape of one or both annular faces.

[0193] A plurality of first-direction (tension) rollers 14 is generally mounted on first annular face 21 and a plurality of second-direction (retract) rollers 16 is generally mounted on second annular face 22.

[0194] Eight first-direction (tension) rollers 14 are spaced at substantially uniform intervals around first annular face 21 of nut member 12.

[0195] Three second-direction (retract) rollers 16 are spaced at substantially uniform intervals around second annular face 22 of nut member 12.

[0196] First-direction (tension) rollers 14 and second-direction (retract) rollers 16 are mounted on nut member 12 at fixed locations.

[0197] In this embodiment, there is a greater number of first-direction (tension) rollers 14 than second-direction (retract) rollers 16 because both payload cables enter and exit the reeling device from its front end, being the payload end. This means that there is a greater forward tension than rearward tension on nut member 12. Accordingly, the retract side may be less strong than the tension side and more tension rollers than retract rollers may be useful to keep the nut member stable.

[0198] Nut member 12 is provided with a torque arm 23 which is supported on a pair of interconnected spherical rod end bearings 24 which are visible in FIGS. 5 to 7. The spherical rod end bearings interconnect torque arm 23 and carriage 42. The connection of the torque arm 23 prevents rotation of nut member 12 in use of the reeling device.

[0199] Referring to FIGS. 9 to 11, each first-direction (tension) roller 14 and each second-direction (retract) roller 16 comprises an annular body 25 having a rim 26. In this embodiment, a tyre is fitted to the annular body. Accordingly, the rim 26 of each roller comprises a tyre. The presence of a tyre is optional. The tyre may be polyurethane or hard nylon, for example.

[0200] The annular body of each roller may be metal (e.g., aluminium or stainless steel) or plastic or a composite material.

[0201] In one embodiment, the inner diameter of annular body 25 is 27 mm; the outer diameter of the roller (including any tyre) is 41 mm; and the width of the roller is 12 mm.

[0202] With reference to FIG. 9, a radial plane P passes through distal end 26e of rim 26 of each roller. A tangent at distal end 26e is parallel to the rotational axis of the roller.

[0203] Each roller is inclined at angle α relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8. Accordingly, each roller is inclined at angle β relative to the longitudinal direction of axial shaft 8.

[0204] In one embodiment, the cross-sectional profile of the leading portion of rim 26 is at an angle α relative to the radial plane P of the roller. Such a cross-sectional profile is shown in FIG. 10 which is a cross-sectional view taken though line A-A of FIG. 11b. The leading portion of rim 26 is the tension portion of the rim, being the front-facing portion of rim 26 in this embodiment.

[0205] Each first-direction (tension) roller 14 has radial plane P which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in a forward direction relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8. In one embodiment, angle α is 24 degrees.

[0206] Accordingly, each first-direction (tension) roller 14 has radial plane P which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in a forward direction relative to the longitudinal direction of the axial shaft. In one embodiment, angle β is 66 degrees.

[0207] Each second-direction (retract) roller 16 has radial plane P which is inclined at an angle in the range of 5 to 60 degrees, preferably 10 to 45 degrees, more preferably 15 to 35 degrees, in a rearward direction relative to a direction which is perpendicular to the longitudinal direction of axial shaft 8. In one embodiment, angle α is 24 degrees.

[0208] Accordingly, each second-direction (retract) roller 16 has radial plane P which is inclined at an angle in the range of 30 to 85 degrees, preferably 45 to 80 degrees, more preferably 55 to 75 degrees, in a rearward direction relative to the longitudinal direction of the axial shaft. In one embodiment, angle β is 66 degrees.

[0209] In this embodiment, the radial plane of each first-direction (tension) roller 14 and the radial plane of each second-direction (retract) roller 16 are inclined at the same angle but in opposite directions relative to a plane which is perpendicular to the longitudinal direction of axial shaft 8.

[0210] Referring to FIGS. 8 and 9, a ball-bearing 28 is provided to enable rotation of each first-direction (tension) roller 14 and second-direction (retract) roller 16. The bearing is annular in shape and comprises a plurality of balls 30, an inner race 32 and an outer race 34, between which the balls are adapted to run. Ball-bearing 28 is located radially inward of annular body 25.

[0211] Each roller is mounted on nut member 12 using a connector 36 and a pair of shaft bushes 38. Shaft bushes 38 act to clamp inner race 32 of ball bearing 28 in place. As shown in FIG. 9, shaft bushes 38 are provided with annular shoulder portions which accommodate and fix inner race 32.

[0212] Shaft bushes 38 are located between connector 36 and ball-bearing 28. Ball-bearing 28 is located between shaft bushes 38 (which surround connector 36) and annular body 25. Inner race 32 is adjacent shaft bushes 38. Outer race 34 is adjacent annular body 25.

[0213] Connector 36 is provided with a screw thread for connection to a threaded aperture 40 provided in nut member 12. Once connected, connector 36 is fixed against rotation.

[0214] Each roller is mounted for rotation about the axis of connector 36.

[0215] Connector 36 may be a socket head cap screw or a counter sunk screw, for example.

[0216] Inner race 32 is stationary in use, relative to nut member 12. Outer race 34 is adapted to rotate with annular body 25 of the roller. As the outer race rotates in use it causes balls 30 to rotate.

[0217] In use of the reeling device, each first-direction (tension) roller 14 and each second-direction (retract) roller 16 rotates about the shaft of connector 36 while engaging helical groove 11. Rim 26 of each roller engages the helical groove on the outer surface of reel 10: the profile of rim 26 is shaped to fit snugly in the profile of the groove. Each roller is urged to rotate by frictional contact with the helical groove.

[0218] In this embodiment, the axis of connector 36 is inclined at angle α relative to the longitudinal direction of axial shaft 8 of the reeling device. The rotational axis of each roller is therefore inclined relative to the rotational axis of reel 10.

[0219] In use, reel 10 is driven to rotate about axial shaft 8 such that first-direction (tension) rollers 14 and second-direction (retract) rollers 16 progress along helical groove 11. Nut member 12 consequently moves in the axial direction of reel 10.

[0220] In this embodiment, nut member 12 moves forward in use between the rear and front ends of reel 10 and moves backwards in use between the front and rear ends of reel 10. In FIG. 1, nut member 12 is positioned closer to the rear end of reel 10. In FIG. 2, nut member 12 is positioned closer to the front end of reel 10.

[0221] Nut member 12 is located between first payload cable 4 coiled on reel 10 and second payload cable 6 coiled on reel 10.

[0222] First-direction (tension) roller 14, second-direction (retract) roller 16, first payload cable 4 and second payload cable 6 share the same helical groove rather than having mutually exclusive helical grooves.

[0223] In general terms, each roller includes a base 27 mounted directly or indirectly on the connector 36, a distal end 26e opposite the base and a pair of sidewalls 29 extending between base 27 and distal end 26e, as shown in FIG. 10. Distal end 26e engages groove 11, as shown in FIG. 9.

[0224] Reeling device 2 comprises a carriage 42 which is arranged for movement in the longitudinal direction of axial shaft 8 along track 44 which is a linear slide track: nut member 12 is connected indirectly to carriage 42.

[0225] Carriage 42 is provided with a diverter sheave 46 for each payload cable. Diverter sheave 46 deflects the payload cable it guides by approximately 90 degrees. For example, when the payload cable is being paid out, the payload cable is diverted from being substantially perpendicular to the longitudinal direction of axial shaft 8 to being substantially parallel to the longitudinal direction of axial shaft 8; and when the payload cable is being pulled in, the payload cable is diverted from being substantially parallel to the longitudinal direction of axial shaft 8 to being substantially perpendicular to the longitudinal direction of axial shaft 8.

[0226] In this embodiment, diverter sheave 46 is a pulley which is mounted for rotation with its radial plane being substantially parallel to the longitudinal direction of axial shaft 8.

[0227] Carriage 42 comprises two opposing brackets 42b which are located on either side of reel 10, these brackets opposing each other in a direction which is substantially transverse to the longitudinal direction of axial shaft 8. Nut member 12 is located between the brackets of the carriage such that a radial plane of the nut member lies in a direction which is substantially transverse to the longitudinal direction of the axial shaft. Between brackets 42b, carriage 42 extends beneath reel 10 (as shown in FIG. 7).

[0228] In this embodiment, as shown in FIGS. 1 to 7, each bracket 42b of carriage 42 is provided with one diverter sheave 46.

[0229] Helical groove 11 has the effect of transporting diverter sheave 46 in the longitudinal direction of axial shaft 8.

[0230] Diverter sheave 46 for second payload cable 6 is shown in FIGS. 1, 2, 6 and 7: diverter sheave 46 for first payload cable 4 is shown in FIGS. 4 and 5.

[0231] Each diverter sheave 46 is aligned in the longitudinal direction of axial shaft 8 with the point of reel 10 at which the payload cable to be diverted is rolled on and off the reel at all times. Hence diverter sheave 46 for first payload cable 4 is positioned closer to the front end of the reeling device than diverter sheave 46 for second payload cable 6.

[0232] As reel 10 rotates in use of the reeling device, one of the payload cables is rolled on the reel and the other payload cable is rolled off the reel. One diverter sheave 46 receives the payload cable being rolled off the reel and diverts it by approximately 90 degrees, guiding the payload cable in a forward direction which is substantially parallel to axial shaft 8. Meanwhile, the other diverter sheave receives the other, paid out payload cable from a direction which is substantially parallel to axial shaft 8 and diverts it by approximately 90 degrees, guiding the payload cable in a rearward direction and then diverting it as it is pulled towards and rolled on the reel.

[0233] With reference to FIGS. 1 and 2, in the case where nut member 12 travels from the rear end to the front end of reel 10, the length of first payload cable 4 rolled on reel 10 decreases and the length of second payload cable 6 rolled on reel 10 increases. The first-direction (tension) rollers and the second-direction (retract) rollers are guided along the helical groove, causing the nut member to slide towards the front end of reel 10.

[0234] Nut member 12 is positioned between the lengths of the first and second payload cables rolled on reel 10. Diverter sheaves 46 and thus carriage 42 move axially along track 44 at the same rate as nut member 12, such that the diverter sheaves are always in the same position relative to the points at which their respective payload cables roll on and off reel 10. As shown in FIGS. 1 to 6, the lengths of the first and second payload cables which are not rolled on reel 10 each enter / leave the body of the reeling device at respective predetermined, stable positions.

[0235] Nut member 12 surrounds reel 10 and is radially spaced from the outer surface of the reel. Referring to FIG. 8, nut member 12 has three arc-shaped bushes 48 connected to second annular face 22. A rear-facing outer surface of each bush 48 is shaped as a portion of a spherical segment: together the three bushes provide a convex spherical bearing surface. Each bush 48 abuts a carriage nut 50 which is substantially annular. The carriage nut is radially spaced from the outer surface of reel 10.

[0236] Spring member 54 extends between carriage nut 50 and nut member 12. In this embodiment, there are two spring members 54 which are each located on diametrically opposite sides of nut member 12 and carriage nut 50 as shown in FIG. 7.

[0237] Carriage nut 50 is mounted between and connected to each bracket 42b of carriage 42 at a connection point 52. Referring to FIG. 7, connection point 52 provides a bearing 52b (e.g., a plastic bearing in a top hat shape) and a connector 52c (e.g., a socket head cap screw) passing through the bearing to connect the bracket to the carriage nut. Connection point 52 in this embodiment also provides a sandwich of annular steel plates 52p which are screwed together and surround bearing 52b. An aperture is provided in each bracket 42b at each connection point 52 to accommodate plates 52p, bearing 52b and connector 52c and thereby enable sliding and rotation of carriage nut 50 about bearing 52b.

[0238] Carriage nut 50 provides an annular concave surface to abut the convex spherical bearing surface provided by the rear-facing outer surfaces of bushes 48. The mating of these concave and convex surfaces, together with the mounting of torque arm 23 and the movement provided at connection point 52, allow nut member 12 to move slightly relative to track 44 thus accommodating deflection and flex of the structure of the reeling device as a load is lifted in use of the device.

[0239] By carrying diverter sheaves 46, brackets 42b are able to transmit force from the diverter sheaves and reel onto nut member 12 via the mounting arrangement of nut member 12 described above and thereby resolve axial tension in the cables in use of the reeling device.

[0240] This mounting arrangement of nut member 12 provides a sliding, gimbal-like mechanism to accommodate some flex and movement of nut member 12 in response to tension changes in the payload cables.

[0241] This mounting arrangement and mechanism are present in the present embodiment to accommodate real world limitations of the exemplified reeling device but they are not essential to the present invention.

[0242] A safety nut 56 is also provided and is coaxial with carriage nut 50 and nut member 12. Safety nut 56 is configured to move in the longitudinal direction of axial shaft 8 at the same rate as carriage nut 50 and nut member 12. Carriage nut 50 is located between nut member 12 and safety nut 56 in FIGS. 3 to 6: with reference to FIG. 9, safety nut 56 extends beneath carriage nut 50 and nut member 12 in the axial direction.

[0243] Safety nut 56 sits independently within groove 11. A small space is provided between safety nut 56 and nut member 12 in the axial direction. When there is wear or other problems with the tension or retract rollers, tension in the payload cable(s) will tend to pull nut member 12 away from the safety nut. The space between safety nut 56 and nut member 12 in the axial direction is monitored and a warning system is triggered if the space increases beyond a certain limit. The warning system shuts down the operation of the reeling device.

[0244] With reference to FIG. 9, safety nut 56 is substantially annular and is provided with a radially-protruding portion having an aperture through which a peg 58 extends in a direction parallel to axial shaft 8. Peg 58 is provided with a screw thread for connection to a threaded aperture provided in carriage 50. Once connected, peg 58 is fixed against rotation. Peg 58 has a shaft and a flange 60 located along the shaft. One end of the shaft is fixed in carriage 50. Flange 60 fits within the aperture in the radially-protruding portion of the safety nut. When reel 10 rotates, light friction between the reel and the safety nut exerts a torque about the safety nut; flange 60 prevents safety nut 56 from rotating as a result of this torque.

[0245] Should the space between nut member 12 and safety nut 56 increase by more than the width of flange 60, the flange moves in an axial direction away from the aperture in the radially-protruding portion. Once flange 60 is located externally of the aperture in the axial direction, only a free end of the shaft of peg 58 is accommodated in the aperture. Since the shaft of peg 58 has a smaller diameter than flange 60, safety nut 56 rotates slightly. This rotation triggers the warning system.

[0246] The operation of the reeling device in its other aspects will be clear to a person skilled in the art from FIGS. 1 to 12 and from the following components which are labelled in the figures.

[0247] A cable chain 62 for electric cables extends in the longitudinal direction of axial shaft 8. The electric cables are connected to load cells 64. A load cell 64 is mounted on each side of carriage 42 and measures the force on the adjacent diverter sheave 46 and thus the force of the payload cable guided by the diverter sheave.

[0248] Electro-magnetic motor 17 comprises a series of motor stators 66 which are co-axial with reel 10 and located within the reel. In this embodiment, five motor stators are used, connected by stator-to-stator link cables 67. Motor stators 66 are surrounded by a cylindrical magnet 68 which in turn is surrounded by a cylindrical iron rotor 69, as shown in FIGS. 5 to 7. Magnet 68 and rotor 69 are co-axial with reel 10 and located within the reel.

[0249] An electrical connector box 70 is provided towards the rear end of the reeling device: cable glands 72 each feed a rear-end electrical item into the connector box; cable glands 74 each feed a front-end electrical item into the connector box.

[0250] Electrical connector box 70 contains housing 76 for spark quenchers, for example. It also contains a terminal block 78 mounted for electrical connections.

[0251] Mounted above electrical connector box 70 is a brake 80 (for example, a two rotor / two coil / double brake or a stage brake). Rearwards of brake 80 is a module connector 82.

[0252] A housing 84 containing a rotary limit switch 86 is provided at the front end of the reeling device. Between housing 84 and motor 17, a coaxial cooling fan 88 is provided inside reel 10.

[0253] The components of the reeling device are supported by an external frame 90 which is elongate in the longitudinal direction of axial shaft 8. In this regard, frame 90 supports, inter alia, brake 80 and housing 84 and reel 10 is mounted therebetween in the longitudinal direction of axial shaft 8.

[0254] In another embodiment, four payload cables replace single payload cable 4. Three additional diverter sheaves 46 are mounted on carriage 42. There is a commensurate reduction in stroke per cable and the axial length of reel 10 is increased. A load pin is provided on each diverter sheave.

[0255] Referring now to FIGS. 13 to 19, there is shown a reeling device 102 in accordance with a further aspect of the present invention. Reeling device 102 is of similar construction to reeling device 2 described above with reference to FIGS. 1 to 7. Equivalent features are shown with corresponding numerals and description thereof will not be repeated.

[0256] In FIGS. 13 to 19, various features including housing 184 and external frame 190 (corresponding to housing 84 and external frame 90 of the previous embodiment) are omitted for clarity. It will be appreciated that the exclusion of such features from FIGS. 13 to 19 does not restrict their inclusion in the embodiments described hereafter. That is, features of the embodiments described above with reference to FIGS. 1 to 12 may be included in the embodiments described below with reference to FIGS. 13 to 19, even if such inclusion is not expressly described below.

[0257] As for the previously described embodiment, reeling device 102 comprises a reel 110 mounted on an axial shaft 108 (shown most clearly in FIG. 17) and a nut member 112 substantially surrounding reel 110 and radially spaced from the outer surface of reel 110. Nut member 112 is arranged to travel in the longitudinal direction of axial shaft 108 as the payload cables are paid out and pulled in from reeling device 102 and is fixed against rotation about axial shaft 108. In this embodiment, nut member 112 has a spherical mounting arranged to transmit a (lower) axial force equally in both directions; whereas in the first embodiment, the spherical bearing was arranged to transmit an axial force in predominantly one direction.

[0258] Nut member 112 comprises first-direction rollers 114 and second-direction rollers 116 that engage a helical groove 111 provided in the outer surface of reel 110. Rotation of first-direction rollers 114 and second-direction rollers 116 effects axial movement of nut member 112 as described above.

[0259] Arrangement of nut member 112, including first-direction rollers 114 and second-direction rollers 116, may be substantially as described above and description thereof will not be repeated.

[0260] First payload cable 104 and second payload cable 106 are fixed to the reeling device 102 and are helically coiled about the outer surface of reel 110 as described above. Nut member 112 is located between the respective lengths of the two payload cables 104, 106.

[0261] Reel 110 is mounted for rotation about axial shaft 108. Upon rotation of the reel in one direction, first payload cable 104 is rolled on the reel and second payload cable 106 is rolled off the reel and, upon rotation of the reel in an opposite direction, first payload cable 104 is rolled off the reel and second payload cable 106 is rolled on the reel.

[0262] Reeling device 102 comprises a first diverter mechanism comprising a first diverter sheave 146a arranged to receive first payload cable 104 from reel 110, and a first compensator sheave 147a arranged to receive first payload cable 104 from first diverter sheave 146a. When being rolled off reel 110, first payload cable 104 passes from reel 110 to first diverter sheave 146a and subsequently to first compensator sheave 147a.

[0263] First diverter sheave 146a diverts first payload cable 104 in a first direction D1 parallel to the longitudinal direction of axial shaft 108. First compensator sheave 147a diverts first payload cable 104 in a second direction D2 parallel to the longitudinal direction of axial shaft 108. As can be seen in FIGS. 13 to 15, in particular, first compensator sheave 147a diverts first payload cable 104 substantially 180 degrees relative to the first direction D1. The first direction D1 is parallel to the second direction D2 and opposes the second direction D2.

[0264] Reeling device 102 further comprises a second diverter mechanism comprising a second diverter sheave 146b arranged to receive second payload cable 106 from reel 110, and a second compensator sheave 147b arranged to receive second payload cable 106 from the second diverter sheave 146b. When being rolled off reel 110, second payload cable 106 passes from reel 110 to second diverter sheave 146b and subsequently to second sheave 147b.

[0265] Second diverter sheave 146b diverts second payload cable 106 in a third direction D3 parallel to the longitudinal direction of axial shaft 108. Second compensator sheave 147b diverts second payload cable 106 in a fourth direction D4 parallel to the longitudinal direction of axial shaft 108. As can be seen in FIGS. 13, 14 and 16, in particular, second compensator sheave 147b diverts second payload cable 106 at substantially 180 degrees relative to the third direction D3. The third direction D3 is parallel to the fourth direction D4 and opposes the fourth direction D4. In the illustrated embodiment, the first, second, third and fourth directions D1, D2, D3, D4 are all parallel with each other and with the longitudinal direction of the axial shaft 108.

[0266] First diverter sheave 146a is aligned in the longitudinal direction of axial shaft 108 with the point of reel 110 at which the first payload cable 104 to be diverted is rolled on and off reel 110 at all times. Similarly, second diverter sheave 146b is aligned in the longitudinal direction of axial shaft 108 with the point of reel 110 at which the second payload cable 106 to be diverted is rolled on and off reel 110 at all times. Hence first diverter sheave 146a of the first diverter mechanism is positioned closer to the front end of the reeling device 102 than second diverter sheave 146b of the second diverter mechanism.

[0267] As reel 110 rotates in use of the reeling device 102, one of the payload cables is rolled on the reel and the other payload cable is rolled off the reel. One of the diverter sheaves 146a, 146b receives the payload cable being rolled off the reel and diverts it by approximately 90 degrees, guiding the payload cable in a forward direction which is substantially parallel to axial shaft 8. Meanwhile, the other diverter sheave 146a, 146b receives the other, paid out payload cable from a direction which is substantially parallel to axial shaft 108 and diverts it by approximately 90 degrees, guiding the payload cable in a rearward direction and then diverting it as it is pulled towards and rolled on the reel. This operation is substantially as described above in relation to the embodiment of FIGS. 1 to 7.

[0268] In contrast to the previous embodiments, each payload cable 104, 106 passes via a compensator sheave 147a, 147b and is diverted by approximately 180 degrees, guiding the payload cable in a direction of the load. Accordingly, in contrast to the previously described embodiments, the payload cables 104, 106 exit the reeling device 102 at its rear end: tension is generated in the rearward direction only. As such, in the embodiment shown in FIGS. 13 to 19, first-direction rollers 114 face generally towards a rear of reeling device 102 in an axial direction (i.e. in a general direction of a tension load applied on the payload cables 104, 106 exiting the reeling device) and second-direction rollers 116 face generally towards a front of the reeling device 102 in an axial direction.

[0269] Provision of compensator sheaves 147a, 147b has been found to significantly reduce (substantially eliminate) the axial load on the first-direction rollers 114. This allows the number of first-direction rollers 114 to be reduced. Additionally, noise generated by first-direction rollers 114 bearing against helical grooves 111 during operation of reeling device 102 is reduced.

[0270] Accordingly, in the illustrated embodiment, only four first-direction rollers 114 are spaced at substantially uniform intervals around nut member 112. Four second-direction rollers 116 are spaced at substantially uniform intervals around nut member 112, however it will be appreciated that alternative embodiments may comprise only three second-direction rollers 116, as for the previous embodiment.

[0271] It will be appreciated that the above benefits of this arrangement are equally applicable to a reeling device provided with only a single payload cable.

[0272] First and second diverter sheaves 146a, 146b are indirectly connected to nut member 112 via a carriage 142. Carriage 142 is arranged for movement in the longitudinal direction of axial shaft 108 along track 144 which is a linear slide track: nut member 112 is connected indirectly to carriage 142.

[0273] Carriage 142 comprises two opposing brackets 142b located on either side of reel 110 and arranged to indirectly connect first and second diverter sheaves 146a, 146b to nut member 112 in the same manner as described above in relation to the embodiment of FIGS. 1 to 7. Accordingly, helical groove 111 has the effect of transporting first and second diverter sheaves 146a, 146b in the longitudinal direction of axial shaft 108.

[0274] Accordingly, as reel 110 rotates, first and second diverter sheaves 146a, 146b move axially along track 144 at the same rate as nut member 112, such that the first and second diverter sheaves 146a, 146b are always in the same position relative to the points at which their respective payload cables roll on and off reel 110.

[0275] First and second compensator sheaves 147a, 147b are rotatably mounted within a compensator carriage 143. Compensator carriage 143 is arranged for movement in the longitudinal direction of axial shaft 108 along track 144.

[0276] Compensator carriage 143 is arranged for concurrent movement with carriage 142 (hereafter ‘diverter carriage’142) in the longitudinal direction of axial shaft 108, such that first and second compensator sheaves 147a, 147b are arranged for concurrent movement with first and second diverter sheaves 146a, 146b.

[0277] Compensator carriage 143 is connected to diverter carriage 142 via a gear mechanism 192 to effect concurrent movement. A gear ratio of gear mechanism 192 is arranged such that a rate of movement of diverter carriage 142 (and thus diverter sheaves 146a, 146b) is greater than a rate of movement of compensator carriage 143 (and thus compensator sheaves 147a, 147b).

[0278] More specifically, a rate of movement of diverter carriage 142 (and thus diverter sheaves 146a, 146b) is two times greater than a rate of movement of compensator carriage 143 (and thus compensator sheaves147a, 147b).

[0279] This is illustrated in FIGS. 18 and 19. FIG. 18 shows reeling device 102 with nut member 112 in a forward position. First payload cable 104 is substantially rolled off reel 110 and second payload cable 106 is substantially rolled on reel 110: nut member 112 is located towards the front of reeling device 102.

[0280] FIG. 19 shows reeling device with nut member 112 in a rearward position. First payload cable 104 substantially rolled on reel 110 and second payload cable 106 substantially rolled off reel 110: nut member 112 is located towards the rear of reeling device 102.

[0281] In FIG. 18, a position of a rotational axis of first compensator sheave 147a in the longitudinal direction is indicated as position X1(A) and a position of a rotational axis of second compensator sheave 147b in the longitudinal direction is indicated as position X1(B). A position of a rotational axis of first diverter sheave 146a in the longitudinal direction is indicated as position Y1(A) and a position of a rotational axis of second diverter sheave 146b in the longitudinal direction is indicated as position Y1(B).

[0282] In FIG. 19, a position of a rotational axis of first compensator sheave 147a in the longitudinal direction is indicated as position X2(A) and a position of a rotational axis of second compensator sheave 147b in the longitudinal direction is indicated as position X2(B). A position of a rotational axis of first diverter sheave 146a in the longitudinal direction is indicated as position Y2(A) and a position of a rotational axis of second diverter sheave 146b in the longitudinal direction is indicated as position Y2(B).

[0283] When the nut member 112 moves from a forward position (FIG. 18) to a rearward position (FIG. 19), a distance travelled by the first compensator sheave 147a is denoted ΔX(A); a distance travelled by the second compensator sheave 147B is denoted ΔX(B); a distance travelled by the first diverter sheave 146A is denoted ΔY(A); and a distance travelled by the second compensator sheave 147B is denoted ΔY(B).

[0284] As can be seen, ΔY(A) is greater than ΔX(A), and ΔY(B) is greater than ΔX(B). Specifically, ΔY(A) is two times greater than ΔX(A), and ΔY(B) is two times greater than ΔX(B).

[0285] With this arrangement, the compensator sheaves 147a, 147b compensate for the change in length of the first and second payload cables 104 and 106 as the nut member 112 (and thus the first and second diverter sheaves 146a, 146b) travels in the longitudinal direction of the axial shaft 108. This ensures that respective ends of the first and second payload cables 104, 106 that are attached to a load are provided in the desired position, despite the change in position along the longitudinal direction of the axial shaft at which the payload cables 104, 106 are rolled on and rolled off the reel 110. Accordingly, the position of the end of the payload cable is determined only by the payload cable being rolled on and off the reel.

[0286] Whilst relative movement of first and second diverter sheaves 146a, 146b and first and second compensator sheaves 147a, 147b is effected by means of gear mechanism 192 in the illustrated embodiment, it will be appreciated that alternative means for effecting the relative movement may be used so as to provide a gearless reeling device.

[0287] One such embodiment is illustrated schematically in FIG. 20, which shows a reeling device 202 comprising a reel 210 and a nut member 212. A single payload cable 204 is shown coiled around reel 210 for clarity, however it will be appreciated that a second payload cable may also be used as for the embodiments previously described.

[0288] A diverter sheave 246 is indirectly connected to nut member 212 via a diverter carriage 242 arranged for movement in the longitudinal direction of an axial shaft (not shown) on which reel 210 is mounted. Carriage 242 moves along a track 244. Diverter sheave 246 diverts payload cable 204 from the reel 210 in a first direction.

[0289] A compensator sheave 247 receives payload cable 204 from diverter sheave 246 and diverts payload cable 204 approximately 180 degrees into a second direction. Compensator sheave 247 is mounted on a compensator carriage 243 that is arranged for concurrent movement with diverter carriage 242 in a longitudinal direction of the axial shaft, along track 244, such that compensator sheave 247 is arranged for concurrent movement with diverter sheave 246.

[0290] Reeling device 202 comprises a cable mechanism 294 for effecting concurrent axial movement of diverter sheave 246 and compensator sheave 247. Cable mechanism 294 comprises a compensator cable 295 having a fixed length, a first sheave 296a (provided on the same rotational axis as compensator sheave 247), a second sheave 296b arranged to receive compensator cable 295 from first sheave 296a and divert compensator cable 295 at approximately 180 degrees, and a third sheave 296c arranged to receive compensator cable 295 from second sheave 296b and divert compensator cable 295 at approximately 180 degrees. A first end 295a of compensator cable 295 is fixed to a chassis 297 that is fixed relative to reel 210 in a longitudinal direction of the axial shaft. A second end 295b of compensator cable 295 is fixed to carriage 242 so as to move with diverter sheave 246 in a longitudinal direction of the axial shaft.

[0291] With this arrangement, movement of nut member 212 in a longitudinal direction of the axial shaft effects a concurrent movement of diverter sheave 246 and compensator sheave 247 in the same direction. Therefore, as payload cable 204 is rolled on and off reel 210, diverter sheave 246 and compensator sheave 247 move concurrently.

[0292] A second position of nut member 212, diverter sheave 246 and compensator sheave 247 is indicated in dashed lines. A distance travelled by compensator sheave 247 is denoted ΔX and a distance travelled by diverter sheave 246 is denoted ΔY.

[0293] A tension of compensator cable 295 is denoted Fc and a tension of payload cable 204 is denoted Fp.

[0294] When the payload cable is in tension:Fc=Fp

[0295] Tension Fp of payload cable 204 acts on diverter sheave 246 (and thus on nut member 212 and rollers mounted thereon) in a first axial direction. Tension Fc of compensator cable 295 acts on nut member 212 (and thus rollers mounted thereon) via carriage 242 in a second axial direction opposing (at 180 degrees relative to) the first axial direction. A sum of the forces acting on diverter sheave 246 (and therefore on rollers mounted on nut member 212) in the longitudinal direction of the axial shaft is:Fc-Fp⁢=0

[0296] Tension Fp of payload cable 204 acts on compensator sheave 247 in the second axial direction. Tension Fc of compensator cable 295 acts compensator sheave 247 in the first axial direction. A sum of the forces acting on compensator sheave 247 in the longitudinal direction of the axial shaft is:2·Fc-2·Fp⁢=0

[0297] Thus, an axial load acting on the or each roller mounted on the nut member 212 in the longitudinal direction of the axial shaft resulting from tension of said payload cable is zero. At the same time, the distance ΔX travelled by compensator sheave 247 is half the distance ΔY travelled by diverter sheave 246 (that is, ΔY is two times greater than ΔX).

[0298] It will be appreciated that further alternative arrangements for effecting concurrent movement of the diverter sheave and compensator sheave may be employed, wherein the resultant axial load on the nut member and rollers is zero, and the rate of movement of the diverter sheave is two times greater than the rate of movement of the compensator sheave. Such mechanisms may include lever mechanisms or hydraulic / fluid-powered mechanisms.

[0299] 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.

Examples

Embodiment Construction

[0157]Referring to FIGS. 1 to 7, a reeling device 2 in accordance with one aspect of the present invention is shown. The reeling device 2 is a winch for the controlled coiling and uncoiling of two payload cables being a first payload cable 4 and a second payload cable 6.

[0158]The reeling device 2 comprises an axial shaft 8, a reel 10 mounted on axial shaft 8, a nut member 12 which is a travelling nut and a plurality of first-direction rollers 14 and a plurality of second-direction rollers 16 mounted on nut member 12.

[0159]Reel 10 has an outer surface about which a length of first payload cable 4 and a length of second payload cable 6 are coiled in use.

[0160]Nut member 12 substantially surrounds reel 10 and is radially spaced from the outer surface of reel 10.

[0161]The outer surface of reel 10 is provided with a helical groove 11 (see FIG. 9) for receiving first payload cable 4, second payload cable 6, first-direction rollers 14 and second-direction rollers 16. In use, these rollers ...

Claims

1. A reeling device for the controlled coiling and uncoiling of a payload cable, the reeling device comprising an axial shaft and a reel mounted on the axial shaft for rotation about the axial shaft, a nut member and at least one roller mounted on the nut member, whereinthe reel has an outer surface about which a length of cable is adapted to be wrapped,the nut member substantially surrounds the reel and is radially spaced from the outer surface of the reel,the outer surface of the reel is provided with a helical groove for receiving one or more payload cables, andthe at least one roller is adapted to rotate while engaging the helical groove,the reeling device further comprising:a diverter sheave directly or indirectly connected to the nut member arranged to receive a payload cable from the reel and divert the payload cable in a first direction, anda compensator sheave arranged to receive said payload cable from the diverter sheave and divert the payload cable in a second direction different to the first direction,wherein the diverter sheave and compensator sheave are arranged for concurrent movement in the longitudinal direction of the axial shaft.

2. A reeling device as claimed in claim 1, wherein the first direction and second direction are arranged such that, in use, when a payload cable is received by the reel, diverter sheave and compensator sheave and is in tension, an axial load acting on the at least one roller in the longitudinal direction of the axial shaft resulting from tension of said payload cable is zero.

3. A reeling device as claimed in claim 1, wherein a rate of movement of the diverter sheave in a longitudinal direction of the axial shaft is greater than a rate of movement of the compensator sheave in the longitudinal direction of the axial shaft.

4. A reeling device as claimed in claim 3, wherein the rate of movement of the diverter sheave in a longitudinal direction of the axial shaft is two times greater than the rate of movement of the compensator sheave in the longitudinal direction of the axial shaft.

5. A reeling device as claimed in claim 1, wherein the first direction is parallel to the second direction.

6. A reeling device as claimed in claim 1, wherein the first direction and / or the second direction is parallel to the longitudinal direction of the axial shaft.

7. A reeling device as claimed in claim 1, wherein the nut member is mounted for movement in the longitudinal direction of the axial shaft and fixed against rotation about the axial shaft.

8. A reeling device as claimed in claim 7, wherein the diverter sheave is directly or indirectly connected to the nut member to move with the nut member in a longitudinal direction of the axial shaft.

9. A reeling device as claimed in claim 8, wherein movement of the diverter sheave in the longitudinal direction of the axial shaft is fixed relative to movement of the nut member in the longitudinal direction of the axial shaft.

10. A reeling device as claimed in claim 7, wherein the reeling device further comprises a carriage which is arranged for movement in the longitudinal direction of the axial shaft and at least one of the nut member and the first diverter sheave is directly or indirectly connected to the carriage.

11. A reeling device as claimed in claim 7, wherein the at least one roller comprises a first direction roller and a second direction roller, the first direction roller is mounted on the nut member and faces generally towards a first end of the reeling device in an axial direction, and second direction roller is mounted on the nut member and faces generally towards an opposing second end of the reeling device in an axial direction.

12. A reeling device as claimed in claim 11, wherein the nut member is substantially annular in shape and has a first annular face and an opposing second annular face, wherein the first annular face is positioned facing the first end of the reeling device and the second annular face is positioned facing the second end of the reeling device and wherein at least one first-direction roller is generally mounted on the first annular face and at least one second-direction roller is generally mounted on the second annular face.

13. A reeling device as claimed in claim 7, wherein the at least one roller has a radial plane which is inclined relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

14. A reeling device as claimed in claim 11, wherein the first-direction roller has a radial plane which is inclined at an angle in the range of 5 to 60 degrees in a first direction relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.

15. A reeling device as claimed in claim 14, wherein the second-direction roller has a radial plane which is inclined at an angle in the range of 5 to 60 degrees in an opposing second direction relative to a direction which is perpendicular to the longitudinal direction of the axial shaft.16.-20. (canceled)21. A reeling device as claimed in claim 7, wherein the reeling device comprises another nut member which substantially surrounds the reel.

22. A reeling device as claimed claim 1, wherein the reeling device comprises an additional reel and an additional nut member which substantially surrounds the additional reel.

23. A reeling device as claimed claim 1, wherein the reel is fixed against movement in the longitudinal direction of the axial shaft.

24. A reeling device as claimed claim 1, wherein the diverter sheave and the compensator sheave form a first diverter sheave and a first compensator sheave, respectively, of a first diverter mechanism for coiling and uncoiling a first payload cable onto the reel,the reeling device further comprising a second diverter mechanism for coiling and uncoiling a second payload cable onto the reel, the second diverter mechanism comprising:a second diverter sheave arranged to receive a second payload cable from the reel and divert the second payload cable in a third direction, anda second compensator sheave arranged to receive said second payload cable from the second diverter sheave and divert the payload cable in a fourth direction different to the third direction.

25. A reeling device as claimed in claim 24, wherein the second diverter sheave is arranged for movement in a longitudinal direction of the axial shaft, said movement of the second diverter sheave being fixed relative to movement of the first diverter sheave of the first diverter mechanism, and wherein the second compensator sheave is arranged for movement in a longitudinal direction of the axial shaft, said movement of the second compensator sheave being fixed relative to movement of the first compensator sheave of the first diverter mechanism.26.-43. (canceled)

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