System comprising a winding assembly and a tensioning tool

Abstract

Embodiments relate to a system (96), a method, and a control apparatus (120). The system (96) comprises a winding assembly (16) and a tensioning tool (100). The winding assembly (16) comprises a tensi

Description

FIELD OF THE INVENTION Embodiments of the present invention relate to a system comprising a winding assembly and a tensioning tool, and additionally to a method. BACKGROUND TO THE INVENTION It is known to load goods on pallets. Lids can be mounted on the loads. Such lids are provided with straps to tighten the lid against the load when the ends of the straps as secured to the pallet. The lids include tightening mechanisms, operated by levers, to tighten the strap, thereby pulling the lid against the load. BRIEF DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION According to various, but not necessarily all, embodiments of the invention there is provided a system comprising a winding assembly and a tensioning tool, wherein the winding assembly comprises: a tensioner movable between a loose position in which a tensioning line is loose relative to the tensioner, and a tensioning position in which the tensioning line is tensioned by the tensioner; a lever comprising a fulcrum body and an elongate handle extending from the fulcrum body, wherein the elongate handle has a stroke length between a first position and a second position; a drive linkage coupling actuation of the elongate handle to motion of the tensioner, wherein movement of the elongate handle from the first position to the second position moves the tensioner from the loose position towards the tensioning position; and a retainer configured to inhibit returning of the tensioner towards the loose position when the elongate handle is returned to the first position, and wherein the tensioning tool comprises: a handle rotator positionable against the elongate handle of the winding assembly. This provides the advantage of greater ease of alignment of the tensioning tool with the winding assembly. Less precision is required to align a handle rotator with the elongate handle than to align a hexagonal key with a hexagonal socket in a bolt head, for example. This reduces the time taken to complete an automated tensioning operation. Optionally, the tensioning tool further comprises an input coupled to the handle rotator, wherein the input is configured to receive force from an actuator apparatus. Optionally, the tensioning tool comprises the actuator apparatus. Optionally, the input is eccentric from the handle rotator. Optionally, the input is rotatable about an axis of rotation. Optionally, the handle rotator is rotatable about the axis of rotation of the input, wherein the handle rotator is eccentric from the axis of rotation of the input. Optionally, the tensioning tool comprises a first aligner and the winding assembly comprises a second aligner, wherein the first and second aligners define an alignment system for aligning the tensioning tool with the winding assembly to position the handle rotator against the elongate handle of the winding assembly. Optionally, the tensioning tool is operable when aligned by the alignment system to move the elongate handle of the winding assembly by the stroke length, via the handle rotator. Optionally, one of the first and second aligners comprises a plug and the other comprises a socket. Alternatively, or additionally, one of the first and second aligners comprises a sensor and the other comprises a target detectable by the sensor. Optionally, at least one of the plug or the socket is tapered in one or more planes to self-align the other of the plug and the socket as the plug and the socket are mated. Optionally, the tapering is shaped to cause self-alignment in first and second orthogonal directions (x, y). An advantage of the tapering is that less complex machinery is required, which results in less investment cost and a lower potential for complicated problems to occur. The tapering means that a lower accuracy is needed for positional and angular alignment. Optionally, the plug is free to rotate in the socket. Optionally, the plug is rotatable in the socket by an angular distance corresponding to at least a stroke length of the elongate handle, or is rotatable in the socket by 360 degrees. Optionally, the plug comprises a tapering sidewall and / or the socket comprises a tapering sidewall, wherein the tapering sidewalls of the plug and socket are engageable with each other. Optionally, at least one of the tapering sidewalls is a tapering frustoconical sidewall. Optionally, the first aligner of the tensioning tool is eccentric from the handle rotator. For example, the input of the tensioning tool may comprise the first aligner. Optionally, the second aligner of the winding assembly is coaxial with an axis of rotation of the elongate handle. Optionally, the winding assembly comprises a housing comprising a cap. Optionally, the cap of the housing covers the drive linkage. Optionally, the cap covers the tensioner. Optionally, the cap covers an axis of rotation of the elongate handle. Optionally, the cap supports an axle of the lever. Optionally, the cap comprises an opening which extends over the elongate handle when the elongate handle is in the second position, to provide vertical access for the handle rotator of the tensioning tool to move the elongate handle of the elongate handle to the second position. Optionally, the opening is positioned above an entrance of a tensioning line channel of the winding assembly. Optionally, the second aligner is formed in the cap of the housing. Optionally, the cap of the housing comprises a recess with tapered walls, defining the second aligner, wherein the second aligner is a socket. Optionally, the lever is configured for hand actuation of the elongate handle. Optionally, the retainer is automatically engaged in dependence on the elongate handle reaching the second position corresponding to the tensioning position of the tensioner. Optionally, the retainer comprises a catch configured to automatically engage following movement of the elongate handle from the first position to the second position, to prevent movement of the elongate handle from the second position to the first position. Optionally, the retainer comprises the catch in the form of a spring-loaded catch, and comprises a spiral cam against which the spring-loaded catch is biased. Optionally, the spiral cam is a single-drop spiral cam, consisting of only one drop into which the spring-loaded catch can be urged. Alternatively, the retainer may comprise a handle retainer to engage with the elongate handle of the elongate handle at the second position. Optionally, the winding assembly comprises a releaser to release the retainer. Optionally, the releaser is push-to-release. Optionally, the releaser is exteriorfacing on the winding assembly, and deflectable by a user’s digit pushing the releaser, to deflect the catch of the retainer out of engagement. Optionally, the releaser and the catch are a common part. Optionally, rotation of the tensioner winds the tensioning line around the tensioner. Optionally, actuation of the elongate handle by the stroke length from the first position to the second position moves (e.g., rotates) the tensioner from the loose position of the tensioner to the tensioning position of the tensioner. Optionally, the stroke length of the elongate handle rotates the tensioner by more than an acute angle. Optionally, the drive linkage has a gear ratio so that the stroke length of the elongate handle rotates the tensioner by a greater angle than the stroke length of the elongate handle. Optionally, the stroke length of the elongate handle rotates the tensioner by a reflex angle. Optionally, the stroke length of the elongate handle is approximately 180 degrees or is an obtuse angle. Optionally, the winding assembly further comprises a return spring to at least bias the elongate handle towards the first position. The first position may be a rest position of the elongate handle. The second position may be a full stroke position of the elongate handle. Optionally, the winding assembly comprises the return spring in a tensioner load path between the elongate handle and the tensioner. Optionally, a bias force of the return spring reaches the elongate handle via the drive linkage. Optionally, the drive linkage of the winding assembly comprises a driver actuatable by the lever, and wherein the tensioner comprises a tensioner drive input directly or indirectly coupled to the driver and actuatable by the driver. Optionally, the tensioner drive input is coupled to the driver by a transmission line such as a cable, or meshes directly or indirectly with the driver. Optionally, the driver and the tensioner drive input are rotatable about different non-parallel axes of rotation. Optionally, the driver and the tensioner drive input are rotatable about perpendicular axes of rotation. Optionally, the driver is rotatable about an upright axis of rotation. Optionally, the tensioner drive input is rotatable about a horizontal axis of rotation. Optionally, an axis of rotation of the tensioner is coaxial with the axis of rotation of the tensioner drive input. Optionally, an axis of rotation of the lever is coaxial with the axis of rotation of the driver. Optionally, the tensioner is rotatable about a tensioner axis of rotation nonparallel to the lever axis of rotation. Optionally, the tensioner axis of rotation is perpendicular to the lever axis of rotation. Optionally, the lever axis of rotation is upright. Optionally, the tensioner axis of rotation is horizontal. Optionally, the tensioner comprises a slotted spindle, slotted to receive the tensioning line therethrough. Optionally, at the loose position of the tensioner, a slot of the slotted spindle is aligned with a direction of a tensioning line channel of the winding assembly. Optionally, at the tensioning position of the tensioner, the slot of the slotted spindle is transverse to the direction of the tensioning line channel. Optionally, the tensioning line comprises a strap. Optionally, the winding assembly comprises a drum axle configured to receive a drum from which the tensioning line can be unwound and to which the tensioning line can be wound. Optionally, the drum axle comprises an urger to bias the drum fitted to the drum axle in a winding direction. Optionally, the system comprises a pallet lid which houses the winding assembly, wherein the pallet lid comprises a cover member extending over the winding assembly above an elevation of the elongate handle. Optionally, the cover member comprises an edge, such as a perimeter edge, located inboard of at least a portion of the elongate handle, to provide vertical access for the handle rotator of the tensioning tool to be positioned against the elongate handle. Optionally, the cover member comprises an opening above the elongate handle to provide vertical access for the handle rotator of the tensioning tool to move the elongate handle of the lever by the stroke length. Optionally, the cover member extends above the cap of the housing of the winding assembly. Optionally, the opening is in the form of a recessed edge of the cover member of the pallet lid. Optionally, the cover member further comprises an opening above the first aligner of the winding assembly, exposing the first aligner. Optionally, the input is rotatable about an axis of rotation eccentric from the handle rotator, wherein movement of the input about the axis of rotation moves the handle rotator to urge the elongate handle of the winding assembly from the first position to the second position According to various, but not necessarily all, embodiments of the invention there is provided a method of operating the system, the method comprising: positioning the handle rotator of the tensioning tool against the elongate handle of the winding assembly; and moving the handle rotator of the tensioning tool to rotate the elongate handle from the first position to the second position. Optionally, positioning the handle rotator comprises positioning the handle rotator against a side of the elongate handle. Optionally, the handle rotator is positioned against only one side of the elongate handle. Optionally, the side of the elongate handle is an inboard-facing side of the elongate handle when the elongate handle is at the first position. Optionally, positioning and moving the handle rotator are performed by an actuator apparatus. Optionally, positioning and moving the handle rotator are performed automatically by the actuator apparatus. Optionally, positioning the handle rotator comprises lowering the handle rotator towards the winding assembly. Optionally, positioning the handle rotator comprises lowering the tensioning tool towards the winding assembly. Optionally, moving the handle rotator comprises rotating the tensioning tool about an axis of rotation. The axis of rotation may be eccentric as defined earlier. Optionally, positioning the handle rotator comprises aligning the handle rotator with the winding assembly. Optionally, lowering the handle rotator causes the aligning. Optionally, lowering the handle rotator mates the first and second aligners of the alignment system, wherein the mating causes the aligning. According to various, but not necessarily all, embodiments of the invention there is provided a control apparatus comprising at least one processor, at least one memory including computer program code which, when executed by the at least one processor, causes execution of the method. Optionally, causing execution of the method comprises sending a control signal to the actuator apparatus to cause the positioning and the moving operations. According to various, but not necessarily all, embodiments of the invention there is provided computer software that, when executed to a computer, causes execution of the method. BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which: FIG. 1 is a perspective view of a lid in use on a load; FIG. 2 is a perspective view of a winding assembly for use in the lid shown in FIG. 1, before a strap is tensioned; FIG. 3 is a perspective view of the winding assembly of FIG. 2, after tensioning the strap; FIG. 4A is a detail view of a handle retainer engaging an elongate handle of a lever and FIG. 4B is a detail view of the handle retainer releasing the elongate handle; FIG. 5A is a detail view of a bevel gear drive linkage and FIG. 5B is a detail view of a worm gear drive linkage; FIG. 6 is a perspective view of an alternative winding assembly for use in the lid shown in FIG. 1, before a strap is tensioned; FIG. 7 is a perspective view of the winding assembly of FIG. 6, after tensioning the strap; and FIGS. 8A-8B illustrate another design of a catch for the alternative winding assembly of FIG. 6; FIG. 9 illustrates an alternative cable actuator; FIG. 10 illustrates a tensioning tool for actuating an elongate handle of a lever of the winding assembly; FIGS. 11A-11B illustrate use of the tensioning tool to actuate the winding assembly; FIG. 12 illustrates an opening in the cover member of the lid, to provide vertical access for the tensioning tool; and FIG. 13 illustrates an example of a control apparatus. DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION FIG. 1 shows a lid 1 for securing a load 2 on a pallet 3. The lid 1 comprises a body 4 with upstanding sides 5 and depending skirt 6 for capping the top sides of the load 2 (and also enabling a plurality of the lids 1 to be nested with each other or with pallets). The body 4 comprises a cover member 7 shown formed by a plurality of plastics mouldings 8, but which could be formed as a single moulding. The body 4 further includes a lower portion 9 formed by a main plastics moulding. The lid 1 includes four tensioning lines in the form of straps 10 (e.g., webbing straps or ropes). Each tensioning line 10 is movable between a retracted condition within the cover member 7, and an extended condition in which the tensioning line 10 extends from the cover member 7. Each tensioning line 10 is provided at a respective side of the lid 1. Each tensioning line 10 has a distal end to which an anchor 14 is attached. An anchor 14 can comprise a hook, loop or any other suitable attacher. In the extended condition of the tensioning lines 10, the anchors 14 can be secured to the pallet 3. As shown in FIGS 2-3, each tensioning line 10 also has a proximal end attached to a drum 12. When the anchors 14 are secured to the pallet 3, as shown in FIG. 1, the tensioning lines 10 can then be tensioned by the use of respective winding assemblies 16 operable on each tensioning line 10. Each winding assembly 16 is provided within the body 4. Only two of the tensioning lines 10 are visible in FIG. 1, extending from two of the sides of the body 4. The skilled person will realise that the other two tensioning lines 10 extend from the other two sides. Each tensioning line 10 may have its own winding assembly 16. FIGS. 2-3 illustrate an example winding assembly 16. The winding assembly 16 may comprise a housing 4b in the form of a plastic moulding securable to a winding assembly aperture in an upstanding side 5 of the body 4 of the lid 1. Alternatively, the winding assembly 16 may be integrally moulded with the body 4 of the lid 1, such that the body 4 of the lid forms the housing. The winding assembly 16 comprises a drum axle 13 configured to receive the drum 12 from which the tensioning line 10 can be unwound when in use, and to which the tensioning line 10 can be re-wound when not in use. The drum axle 13 may comprise an urger (hidden from view), such as a spring connected at one end to the drum axle 13 and at the other end to the drum 12. The urger rotatably biases the drum 12 in a winding direction to wind the tensioning line 10 on the drum 12, to move the tensioning line 10 to its retracted condition. For example, the urger may comprise a spiral spring. The tensioning line 10 extends away from the drum 12 along a tensioning line channel 22 and through a tensioning line opening 24 in the lateral exterior of the winding assembly 16. The tensioning line channel 22 interconnects a drum cavity / the drum 12 with the tensioning line opening 24. The anchor 14 of the tensioning line 10 may be oversized relative to the tensioning line opening 24 so that the distal end of the tensioning line 10 can be easily retrieved and is not 'swallowed' by the winding assembly 16. Each winding assembly 16 comprises a tensioner 37 in the form of a slotted spindle 40. The tensioner 37 is actuated to pull the tensioning line 10 once the anchor 14 of the tensioning line 10 has been secured to the pallet 3. The tensioner 37 is rotatably mounted in the winding assembly 16. The tensioner 37 spans across the tensioning line channel 22 and engages with the tensioning line 10. The illustrated tensioner 37 is rotatable about a lateral, tensioner axis of rotation 62 perpendicular to the vertical axis of rotation of the drum 12. This ensures that the winding assembly 16 is low-height. The tensioner 37 is rotatable by operation of a drive linkage actuated by an operating member in the form of a lever 19. The illustrated lever 19 comprises a fulcrum body 21 and an elongate handle 20 extending from the fulcrum body 21, which a user can turn. The drive linkage, tensioner 37, and axle / axis of rotation of the lever 19 are housed by a housing 88. Although not shown in FIGS. 2-3, the housing 88 further comprises an upper cap 90 (FIGS. 11A-11B) separate from the cover member 7 of the pallet lid 1. The upper cap 90 covers the moving parts, except the elongate handle 20 of the lever 19 which protrudes horizontally from the housing. The lever 19 is operated by pivotally moving its elongate handle 20 about a lever axis of rotation 61 from a first position (rest position) defining a start of the stroke length of the elongate handle 20 (FIG. 2) to a second position defining the end of its stroke length (FIG. 3). The lever axis of rotation 61 may be an upwards axis such as a vertical axis. Therefore, the lever 19 may move laterally. This ensures that the winding assembly 16 is low-height. The illustrated tensioner 37 has a slotted spindle 40 defining a slot 38 through which the tensioning line 10 passes. The tensioner 37 is rotatably held in the winding assembly 16 by bearings 41 A, 41B. By rotating the slotted spindle 40 after the tensioning line 10 has been anchored to the pallet 3, the tensioning line 10 is wound around the slotted spindle 40 which pulls any slack in the tensioning line 10 to tension the tensioning line 10. In another embodiment, the tensioner 37 has an eccentric cross-section, and is rotatable so that a nose of the eccentric cross-section clamps the tensioning line 10 against a reaction surface such as a recess in a base of the channel 22, or any other appropriate reaction surface. Such a tensioner 37 may not require a slot 38. The movement of the elongate handle 20 from the rest position to the end of the stroke length rotates the slotted spindle 40 from a loose position (home position) of the slotted spindle 40 to a tensioning position of the slotted spindle 40. This wraps the tensioning line 10 around the slotted spindle 40 to tension the anchored tensioning line 10. Only one stroke of the elongate handle 20 is necessary. When the slotted spindle 40 is at the home position, its slot 38 may be aligned with the direction in which the tensioning line 10 can be wound and unwound, to not resist pulling of the tensioning line 10 therethrough. The slot 38 may be parallel to the tensioning line channel 22. The slot 38 may face the tensioning line opening 24. The tensioning line 10 is therefore loose relative to the slotted spindle 40 in the home position. When the slotted spindle 40 is at the tensioning position, as shown in FIG. 3, the tensioning line 10 is sufficiently wound around the slotted spindle 40 to tension the tensioning line 10 and frictionally react against further unwinding of the tensioning line 10. The angular distance from the home position of the slotted spindle 40 to the tensioning position of the slotted spindle 40 may be a reflex angle. The elongate handle 20 may have a stroke length of approximately 180 degrees (or a different, obtuse angle). Only one stroke of the elongate handle 20 (e.g., 180 degrees) is necessary to rotate the slotted spindle 40 by the reflex angle (e.g., 300 degrees). The drive linkage has the necessary diameter ratio / gear ratio to effect this single-stroke operation. It would be appreciated that a tensioner 37 could be implemented in another manner than via a slotted spindle. For example, the slotted spindle could be replaced by an over-centre cam (not shown) at the same location, rotatable to compress the webbing of a strap 10 against a reaction surface, such as a base of the tensioning line channel 22. As the nose of the cam approaches perpendicular to the reaction surface, the normal compressive force of the tensioning line 10 increases to create sufficient traction to drag the tensioning line 10 back in a tensioning direction. Once the nose of the cam has passed over-centre (nose passes perpendicular), the tensioning line 10 is tensioned. Further it is difficult to unwind the tensioning line 10 by pulling on the tensioning line 10 because pulling hard increases the friction. In FIGS. 2-3, a non-slip drive linkage couples the lever 19 to the tensioner 37. The non-slip drive linkage has a driver 18 actuatable by the lever 19, and a tensioner drive input 42 connected to the tensioner 37. The driver 18 and tensioner drive input 42 may connect directly as shown in FIGS. 5A-5B, or indirectly via a transmission line 53 shown in FIGS. 2-3. If the non-slip drive linkage is a mesh drive linkage, the driver 18 may be a sprocket actuatable by the lever 19; the tensioner drive input 42 may be a sprocket; and the transmission line 53 may be a transverse-ribbed belt or chain that meshes with the sprockets 18, 42 If the non-slip drive linkage is instead a cable actuator, the transmission line 53 would be a wire or wire rope, connected at one end to a radial part of the driver 18 and at the other end to a radial part of the tensioner drive input 42. The driver 18 may be an integral part of the fulcrum body 21 of the lever 19. For example, the lever 19 may be comprised of an elongate handle 20 connected to a driver 18, defining a Class 2 lever. The mechanical advantage of the lever 19 is the radius of the distal end of the elongate handle 20 from the lever axis of rotation 61, divided by the shorter radius of the driver 18 from the lever axis of rotation 61. The tensioner drive input 42 is coaxial with and connected to the slotted spindle 40. The tensioner drive input 42 may be integrally moulded with, or secured to, the slotted spindle 40. The tensioner axis of rotation 62 of the tensioner drive input 42 is perpendicular to the lever axis of rotation 61 about which the driver 18 rotates. Therefore, the drive loop 53 can comprise a quarter-twist to connect the axes. FIGS. 5A-5B illustrate example alternative implementations of a drive linkage connecting different axes. Instead of a sprocket and a loop, the driver is a gear and the tensioner drive input is a gear. The driver gear meshes directly or indirectly with the tensioner drive input gear. In FIG. 5A, the driver gear is a bevel gear 18A and the tensioner drive input gear is a bevel gear 42A. In FIG. 5B, the driver gear is a worm drive 18B and the tensioner drive input gear is a worm wheel 42B. Returning to FIGS. 2-3, the winding assembly 16 is provided with a handle retainer 70 configured to engage with the elongate handle 20 of the lever 19 following actuation of the lever 19 in a first, tensioning direction (from the rest position of the elongate handle 20 to the end of the stroke length of the elongate handle 20), to prevent movement of the elongate handle of the elongate handle 20 in a second, opposite direction despite the bias force from the urger of the drum axle 13 biasing the elongate handle 20 back towards its rest position. FIG. 2 shows the elongate handle 20 at its rest position wherein the tensioner 37 is at its home position. FIG. 3 shows the elongate handle 20 at its full stroke position wherein the tensioner 37 is at its tensioning position. In FIG. 3, the elongate handle 20 of the lever 19 is engaged with the handle retainer 70. FIGS. 4A-4B show the handle retainer 70 in more detail. The handle retainer 70 comprises a catch 72 configured to automatically (i.e., without user intervention) engage and hold the elongate handle 20 of the lever 19 when the elongate handle 20 of the lever 19 is moved into the catch 72 (the full stroke position of the elongate handle 20). The catch 72 operates in the manner of a one-way gate that the lever 19 can enter but cannot leave without first undoing the catch 72. The catch 72 is implemented as a snap-fit catch 72. The snap-fit catch 72 is in the path of the elongate handle 20. The elongate handle 20 pushes against the snap-fit catch 72 to deflect the snap-fit catch 72 away from its neutral undeflected position, for example by flexing the snap-fit catch 72. The axis of flex / rotation of the snap-fit catch 72 may be a lateral axis. When the elongate handle 20 passes an over-centre detent 74 of the snap-fit catch 72, the snap-fit catch 72 toggles into engagement with the elongate handle 20. The whole elongate handle 20 may be within the detent 74. The detent 74 is hook-shaped to create the over-centre actuation. The elongate handle 20 is itself shaped to deflect the snap-fit catch 72 until the portion of the elongate handle 20 settles into the detent 74. As shown, the elongate handle 20 comprises a curved surface to deflect the snap-fit catch 72. Alternatively, the surface could be sloped and ramp-like. Likewise, the snap-fit catch 72 comprises a sloped and / or curved deflection surface for deflection by the elongate handle 20. The shape of the detent 74 of the snap-fit catch 72 may also match a portion of the cross-section shape of the elongate handle 20 (e.g., oval shaped in the Figures). As shown in FIGS. 2-3, the handle retainer 70, the elongate handle 20 and the tensioning line opening 24 are exterior parts of the winding assembly 16. They are at an upstanding side 5 of the lid 1 of FIG. 1. Therefore, a user can grab the elongate handle 20, turn the elongate handle 20 and see how the elongate handle 20 is engaged. The engagement of the elongate handle 20 into the handle retainer 70 provides clear feedback that the tensioning line 10 is now sufficiently tensioned. As shown in FIGS. 2-3, the handle retainer 70 is aligned with a distal end portion of the elongate handle 20, distal from the fulcrum body 21 of the lever 19. The term 'distal end portion' refers to alignment with the end or to the final third, quarter or fifth of the length of the elongate handle 20 (length not including the radius of the fulcrum body 21). To release the elongate handle 20 from the handle retainer 70, the user pushes (e.g., flexes) the catch 72 vertically with their finger, to separate the detent 74 from the elongate handle 20. The deflection surface of the catch 72 may function as the handle releaser by being sized to receive a user's fingertip. This disengagement of the handle retainer 70 is sufficient to allow the urger of the drum axle 13 to pull the line 10 hard enough to rotate the tensioner 37 back to its home position, the back-rotation of the tensioner 37 causing rotation of the elongate handle 20 back to its rest position. The tensioning line 10 is now slack which allows the user to separate the anchor 14 from the pallet 3 and retract the tensioning line 10. FIGS. 6-7 show an alternative design of retainer 70B, compared to the handle retainer 70 of FIGS. 2-4. Relative to the handle retainer 70 of FIGS. 2-4, the retainer 70B engages a downstream part of the drive linkage connecting the handle to the tensioner. This downstream retainer 70B is at least partially hidden / internal rather than being exposed. The retainer 70B of FIGS. 6-7 comprises a single-drop spiral cam 76 comprised in the fulcrum body 21 of the lever 19, and a spring-loaded catch 72B configured to engage with the spiral cam 76. The axis of the spiral cam 76 may be coaxial with the lever axis of rotation 61. The illustrated spiral cam 76 is above the driver 18, but could alternatively be below the driver 18. The retainer 70B is configured to engage with the lever 19 following actuation of the elongate handle 20 in the first, tensioning direction (from the rest position of the elongate handle 20 to the end of the stroke length of the elongate handle 20), to prevent movement of the elongate handle 20 in the second, opposite direction despite the bias force from the urger of the drum axle 13 biasing the lever 19 back towards the rest position of the elongate handle 20 of the lever 19. FIG. 6 shows the elongate handle 20 at its rest position wherein the tensioner 37 is at its home position. As the elongate handle 20 is rotated to the full stroke position shown in FIG. 7, the rotating spiral cam 76 deflects the catch 72B, acting against the spring 80 of the catch 72B. FIG. 7 shows the elongate handle 20 at its full stroke position wherein the tensioner 37 is at its tensioning position. In FIG. 7, the retainer 70B is in an engaged state. Specifically, the catch 72B has fallen into the drop 77 of the spiral cam 76. Therefore, when the user releases the handle 20, the elongate handle 20 remains stationary because the spiral cam 76 is unable to back-rotate due to the engagement between the catch 72B and the drop 77 of the spiral cam 76. The catch 72B operates in the manner of a one-way gate that the spiral cam 76 can enter but cannot leave without first undoing the catch 72B. The catch 72B is implemented as a spring-loaded catch 72B. As shown in FIGS. 6-7, the elongate handle 20 and the tensioning line opening 24 are exterior parts of the winding assembly 16. They are at an upstanding side 5 of the lid 1 of FIG. 1. Therefore, a user can grab the elongate handle 20, turn the elongate handle 20 and feel the elongate handle 20 being engaged by the retainer 70B. The engagement of the retainer 70B provides clear haptic feedback that the tensioning line 10 is now sufficiently tensioned. To release the elongate handle 20 from the retainer 70B, the user pushes a releaser in the form of a release button 78 with their finger, to separate the catch 72B from the drop 77 of the spiral cam 76. The release button 78 is sized to receive a user's fingertip. This disengagement of the retainer 70B by the release button 78 may or may not be sufficient to allow the urger of the drum axle 13 to pull the line 10 hard enough to rotate the tensioner 37 back to its home position. Should the urger of the drum axle 13 not be powerful or consistent enough to cause rotation of the tensioner 37 to its home position, a return spring 82 can be provided. FIGS. 6-7 illustrate an example return spring 82, described below. One end of the illustrated return spring 82 is connected to the slotted spindle 40 and another end of the return spring 82 is attached to the housing of the winding assembly 16. The return spring 82 is wrapped around the slotted spindle 40. The return spring 82 is configured to bias the tensioner 37 back to its home position upon actuation of the release button 78. If the handle 20 is connected to the slotted spindle 40 via a non-slip drive linkage, then the return spring 82 is able to simultaneously bias the tensioner 37 back to its home position and the elongate handle 20 to its rest position. Otherwise, a separate return spring may be provided for the lever 19 at the cost of an increased part count. In other implementations, the return spring 82 could be connected to another part of the tensioner load path connecting the handle 20 to the rotation of the slotted spindle 40. In some examples, a return spring 82 of the type described in relation to FIGS. 6 and 7 could be employed in the winding assembly 16 of FIGS. 2 to 4B. The tensioning line 10 is now slack which allows the user to separate the anchor 14 from the pallet 3 and retract the tensioning line 10. The release button 78, the catch 72B, and optionally the spring 80, may be an integral part such as an integrally-moulded part. This obviates the need for a mechanism connecting the release button 78 to the catch 72B, or multiple parts during manufacture. For intuitive use, the release button 78 is an exterior part of the winding assembly. The release button 78 is adjacent the lever 19. The release button 78 is exposed at the upstanding side 5 of the lid 1 of FIG. 1. The spring 80 may be internal and anchored against a part of the lid 1 of FIG. 1. FIG. 9 illustrates a further example cable actuator providing a non-slip drive. As shown in the detail view of FIG. 9, the transmission line 53B is in the form of a cable. The cable is connected at one end to a first seat 92 mounted to the lever 19, and connected at its opposite end to a tensioner drive input 42B of the tensioner 37, the input 42B being in the form of a second seat. The seats 42B, 92 and cable 53B define a winding mechanism. It would be appreciated that a different form of connection could be provided, in other examples. It would be appreciated that a different type of retainer and / or releaser could be implemented than that shown. FIGS. 10-11B illustrate a system 96 comprising the winding assembly 16 and a tensioning tool 100. The system 96 is an automated winding system. The winding assembly 16 is not limited to the example shown, and may be as described in any of the preceding examples. The tensioning tool 100 comprises an input 104 which is attached in an unspecified manner to an actuator apparatus 110. The input 104 may comprise any appropriate connector to connect it to the actuator apparatus 110. The actuator apparatus 110 comprises one or more actuators. The tensioning tool 100 comprises an output in the form of a handle rotator 102 which is positionable against a side of the elongate handle 20 of the lever 19, as shown in FIGS. 11A-11B. The actuator apparatus 110 is operable to firstly translate the tensioning tool 100 in a downwards direction to position the handle rotator 102 into a space 99 behind the elongate handle 20 when the elongate handle 20 is in the rest position. The space 99 is located inboard of the elongate handle 20 in the rest position. This is represented in FIG. 11A. The handle rotator 102 is then rotated to rotate the elongate handle 20 of the lever 19 of the winding assembly 16. The space 99 behind the elongate handle 20 is accessible from above the pallet lid 1. FIG. 12 shows that a perimeter edge 98 of the cover member 7 of the pallet lid 1 comprises a recessed portion defining an opening 94, through which the tensioning tool 100 can be lowered into the space 99 behind the elongate handle 20 in the rest position. The perimeter edge 98 of the cover member 7 is shaped so that the elongate handle 20 remains outboard of the perimeter edge 98 of the cover member 7 between the rest position and full stroke position of the elongate handle 20. The input 104 of the tensioning tool 100 is rotatable by the actuator apparatus 110, and is eccentric from the handle rotator 102. The input 104 and the handle rotator 102 together define a paddle shape. Specifically, the input 104 is connected to the handle rotator 102 by a radially-extending transverse member 101, and the handle rotator 102 protrudes downwardly from the transverse member 101. It would be appreciated that the shape of the tensioning tool 100 may differ depending on the implementation. A control apparatus 120 may be configured to control the actuator apparatus 110 to translate the tensioning tool 100 downwardly to engage the handle rotator 102 with the elongate handle 20, and then rotate the input 104 so that the handle rotator 102 rotates the handle from the home position to the full stroke position. The tensioning tool 100 and winding assembly 16 comprise an alignment system so that as the tensioning tool 100 translates downwardly, a horizontal alignment is performed to coaxially align a portion of the tensioning tool 100 with a portion of the winding assembly 16, in x- and y- axes. This ensures that when the handle rotator 102 is rotated, it remains located against the side of the elongate handle 20 for the entire stroke of the elongate handle 20. Specifically, the tensioning tool 100 comprises a plug 106 defining a first aligner, and the cap 90 of the winding assembly 16 comprises a socket 84 defining a second aligner. As best shown in FIG. 10, the plug 106 comprises a downwards-facing protrusion with a circular frustoconically tapering sidewall 108, mounted to an underside of the tensioning tool 100 beneath the input 104 and coaxial with the input 104. The socket 84 is an upwards-facing circular recess formed in the cap 90 of the winding assembly 16, with a circular curved perimeter sidewall 86. The socket 84 is coaxially located above the lever axis of rotation. The sidewalls 108, 86 of the plug 106 and socket 84 define lead-in surfaces to perform horizontal (x- and y-axes) self-alignment as they are brought together. The plug 106 and socket 84 allow full freedom of rotation. Before this selfalignment, an initial coarse alignment may be performed, but the details are outside the scope of this disclosure. The cap 90 of the housing 88 of the winding assembly 16 has an outboard perimeter edge 97 which is located below the perimeter edge 98 of the cover member 7 of the pallet lid 1, when the winding assembly 16 is seated with the body 4 of the pallet lid 1. The perimeter edge 97 of the cap 90 of the housing 88 of the winding assembly 16 is shaped so that the elongate handle 20 of the lever 19 remains outboard of said perimeter edge 97, between the rest position and full stroke position. Therefore, interference between the tensioning tool 100 and the cap 90 of the housing 88 is avoided. FIG. 11A illustrates the perimeter edge 97 of the cap 90 comprising a recess-type opening 92 for this purpose, in which the perimeter edge 97 is recessed to provide vertical clearance above the elongate handle 20 when the elongate handle 20 is in the full stroke position. The opening 92 of the cap 90 of the housing 88 of the winding assembly 16 is positioned above an entrance of a tensioning line channel of the winding assembly 16, because the elongate handle 20 at the full stroke position is located above the tensioning line channel. Motion of the tensioning tool 100 may be controlled by a control apparatus 120 as shown in FIG. 13. The control apparatus 120 comprises at least one processor 122, at least one memory 124 including computer program code 126 which, when executed by the at least one processor 122, causes execution of a method comprising: positioning the handle rotator 102 of the tensioning tool 100 against the elongate handle 20 of the winding assembly 16; and moving the handle rotator 102 of the tensioning tool 100 to rotate the elongate handle 20 from the rest position to the full stroke position. As described earlier, positioning the handle rotator 102 can comprise, after an initial coarse alignment of the plug 106 and socket 84, controlling the actuator apparatus 110 to lower the tensioning tool 100 towards the space 99 behind the elongate handle 20, until the handle rotator 102 is located horizontally adjacent to a side of the elongate handle 20. This operation lowers the plug 106 into the socket 84, therefore causing fine self-alignment in x- and y-axes between the tensioning tool 100 and the winding assembly 16. Then, the control apparatus 120 controls the actuator apparatus 110 to rotate the input 104 of the tensioning tool 100. This rotates the handle rotator 102 of the tensioning tool 100 about an axis of rotation which is generally coaxial with the lever axis of rotation. The elongate handle 20 is rotated to the full stroke position, which tensions the winding assembly 16. In examples where the pallet lid 1 comprises multiple winding assemblies, the above method can optionally be performed by a plurality of tensioning tool 100s simultaneously, to tension all of the winding assemblies. Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. For example, aspects of the invention are applicable to winding assemblies with ratchet mechanisms, that require multiple turns of the elongate handle 20 to rotate the tensioner to its tensioning position. In some examples, one of the first and second aligners comprises a sensor and the other comprises a target detectable by the sensor. Features described in the preceding description may be used in combinations other than the combinations explicitly described. Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not. Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and / or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A system comprising a winding assembly and a tensioning tool, wherein the winding assembly comprises:a tensioner movable between a loose position in which a tensioning line is loose relative to the tensioner, and a tensioning position in which the tensioning line is tensioned by the tensioner;a lever comprising a fulcrum body and an elongate handle extending from the fulcrum body, wherein the elongate handle has a stroke length between a first position and a second position;a drive linkage coupling actuation of the elongate handle to motion of the tensioner, wherein movement of the elongate handle from the first position to the second position moves the tensioner from the loose position towards the tensioning position; anda retainer configured to inhibit returning of the tensioner towards the loose position when the elongate handle is returned to the first position, andwherein the tensioning tool comprises:a handle rotator positionable against the elongate handle of the winding assembly.

2. The system of claim 1, wherein the tensioning tool further comprises an input coupled to the handle rotator, wherein the input is configured to receive force from an actuator apparatus.

3. The system of claim 2, wherein the input is rotatable about an axis of rotation, wherein the handle rotator is rotatable about the axis of rotation of the input, wherein the handle rotator is eccentric from the axis of rotation of the input, wherein movement of the input about the axis of rotation moves the handle rotator to urge the elongate handle of the winding assembly from the first position to the second position.

4. The system claim 1,2, or 3, wherein the tensioning tool comprises a first aligner and the winding assembly comprises a second aligner, wherein the first and second aligners define an alignment system for aligning the tensioning tool with the winding assembly to position the handle rotator against the elongate handle of the winding assembly.

5. The system of claim 4, wherein the tensioning tool is operable when aligned by the alignment system to move the elongate handle of the winding assembly by the stroke length, via the handle rotator.

6. The system of claim 4 or 5, wherein one of the first and second aligners comprises a plug and the other comprises a socket, and / or wherein one of the first and second aligners comprises a sensor and the other comprises a target detectable by the sensor.

7. The system of claim 6, wherein at least one of the plug or the socket is tapered in one or more planes to self-align the other of the plug and the socket as the plug and the socket are mated.

8. The system of claim 6 or 7, wherein the plug is free to rotate in the socket, wherein the plug is rotatable in the socket by an angular distance corresponding to at least a stroke length of the elongate handle, or is rotatable in the socket by 360 degrees.

9. The system of any preceding claim, wherein the winding assembly comprises a housing comprising a cap.

10. The system of claim 9, wherein the cap of the housing covers the drive linkage, wherein the cap covers the tensioner, wherein the cap covers an axis of rotation of the elongate handle.

11. The system of claim 9 or 10, wherein the cap comprises an opening which extends over the elongate handle when the elongate handle is in the second position, to provide vertical access for the handle rotator of the tensioning tool to move the elongate handle of the elongate handle to the second position.

12. The system of claim 9, 10, or 11 as dependent through claim 4, wherein the second aligner is formed in the cap of the housing, wherein the cap of the housing comprises a recess with tapered walls, defining the second aligner, wherein the second aligner is a socket.

13. The system of any preceding claim, wherein the retainer is automatically engaged in dependence on the elongate handle reaching the second position corresponding to the tensioning position of the tensioner, wherein the retainer comprises a catch configured to automatically engage following movement of the elongate handle from the first position to the second position, to prevent movement of the elongate handle from the second position to the first position.

14. The system of any preceding claim, wherein the drive linkage of the winding assembly comprises a driver actuatable by the lever, wherein the tensioner comprises a tensioner drive input directly or indirectly coupled to the driver and actuatable by the driver, wherein the tensioner drive input is coupled to the driver by a transmission line such as a cable, or meshes directly or indirectly with the driver.

15. The system of any preceding claim, wherein the tensioner comprises a slotted spindle, slotted to receive the tensioning line therethrough.

16. The system of any preceding claim, wherein the winding assembly comprises a drum axle configured to receive a drum from which the tensioning line can be unwound and to which the tensioning line can be wound.

17. The system of any preceding claim, wherein the system comprises a pallet lid which houses the winding assembly, wherein the pallet lid comprises a cover member extending over the winding assembly above an elevation of the elongate handle, wherein the cover member comprises an edge, such as a perimeter edge, located inboard of at least a portion of the elongate handle, to provide vertical access for the handle rotator of the tensioning tool to be positioned against the elongate handle.

18. The system of claim 17, wherein the cover member comprises an edge, such as a perimeter edge, located inboard of at least a portion of the elongate handle, to provide vertical access for the handle rotator of the tensioning tool to be positioned against the elongate handle, wherein the cover member comprises an opening above the elongate handle to provide vertical access for the handle rotator of the tensioning tool to move the elongate handle of the lever by the stroke length.

19. The system of claim 17 or 18 as dependent through claim 4, wherein the cover member further comprises an opening above the first aligner of the winding assembly, exposing the first aligner.

20. A method of operating the system as claimed in any one of the preceding claims, the method comprising:positioning the handle rotator of the tensioning tool against the elongate handle of the winding assembly; andmoving the handle rotator of the tensioning tool to rotate the elongate handle from the first position to the second position.

21. The method of claim 20, wherein positioning the handle rotator comprises positioning the handle rotator against a side of the elongate handle.

22. The method of claim 20 or 21, wherein positioning and moving the handle rotator are performed automatically by an actuator apparatus.

23. The method of claim 20, 21, or 22, wherein positioning the handle rotator comprises lowering the handle rotator towards the winding assembly, wherein moving the handle rotator comprises rotating the tensioning tool about an axis of rotation.

24. The method of any one of claims 20 to 23 as dependent through claim 4, wherein positioning the handle rotator comprises aligning the handle rotator with the winding assembly, wherein lowering the handle rotator mates the first and second aligners of the alignment system, wherein the mating causes the aligning25. A control apparatus comprising at least one processor, at least one memory including computer program code which, when executed by the at least one processor, causes execution of the method as claimed in any one of claims 20 to 24.

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