NZ533772A - A tensioning apparatus using a rotating forked spindle to tension a strap - Google Patents

Abstract

Apparatus (1) for tensioning a strap is disclosed. A forked spindle (4) having two tines is rotatably mounted in a frame (18) and one of the tines (41) is longer than the other (42). A tightening means, such as a ratchet, rotates the spindle in a first direction, while release means operate to allow the spindle to rotate in the opposite direction. A strap is positioned in the slot (40) between the tines of the spindle by movement other than threading the strap through the slot. For example, the spindle can be moved relative to the frame so that the shorter tine (42) does not extend between side plates (2, 3) of the frame, allowing access to the slot from the free end of the shorter tine.

Description

Patents Form # 5 NEW ZEALAND Patents Act 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL # : 533772/538708 DATED : 25 June 2004 / 9 March 2005 TITLE : A Tensioning Apparatus We, GREYSON MANUFACTURING LIMITED Address: 338 Whites Road, Putaruru, New Zealand Nationality: A New Zealand company do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: 130704NZB Cap _20050802_l441 _NlC.doc l:ELi CODK 1050 'NTELLECTUALFPRoPERfY 0FF(CE ~ 8 AUG 2005 —iVFn 0 This invention relates to a tensioning apparatus and has been devised particularly although not necessarily solely for use as a ratchet tie down or a winch for use on trucks, trailers, trays and in other instances where it is desired to tie down a strap or webbing (hereinafter referred to as "a strap").

When using tie downs or winches of the type currently used to tension the tie down straps on trucks, lorries, trailers, trays and other devices the tie downs provide a rotatable spindle which has a slot in it. The strap is threaded through the slot and then by use of a ratchet action the strap is tightened. When releasing these straps or webbing the ratchet is disengaged and the spindle free wheels around the spindle to a loosened position whereupon 10 the strap can be withdrawn by pulling it back through the slot.

Frequently the tail on the strap or webbing is somewhat lengthy and therefore a substantial amount of strap must be fed lengthwise through the slot in the spindle before the ratchet construction can be operated to tighten or tension the strap. Frequently the engagement, and indeed the disengagement, of the strap or occurs in wet conditions and possibly on a wet or 15 muddy surface. The operation of threading the strap or webbing through the slot in the spindle can therefore be both time consuming and muddy or otherwise dirty. Removing the strap is likewise time consuming and may be also be a dirty operation. When tensioned the tail of the strap or webbing is often tied into a knot to stop the tail dragging on the ground. In order to release the strap or webbing, the knot must be untied which again is time 20 consuming. Furthermore any frayed end is difficult or almost impossible to feed through the slot. Clearly this is disadvantageous.

It is therefore an object of the present invention to provide a tensioning device such as a tie down or a winch which will obviate or minimise the foregoing disadvantages in a simple yet effective manner or which will at least provide the public with a useful choice.

Accordingly, the invention consists in a tensioning apparatus comprising a frame, a bifurcated spindle providing two spindle tines one of which is longer than the other, the spindle being mounted on the frame for rotational movement thereon and defining a slot between the two spindle tines, tightening means operable to rotate the spindle in a first direction, release means operable to cause or allow the spindle to rotate in the opposite 30 direction, and the spindle being shaped or able to be configured so that in use a strap may be positioned within the slot formed in the bifurcated spindle by movement other than threading the strap lengthwise of the strap, through the slot. 130704NZB Ps 20050805 1 011 NK..doc/CW/nk intellectual property office of n.2. 2 9 JAN 2007 Preferably the frame has a pair of spaced apart side plates and the spindle being moveable relative to the frame so that the spindle is moveable between a first position wherein both spindle tines extend between the side plates and a second position wherein at least one spindle tine does not extend between the side plates to allow access to the slot from the free 5 end of the shorter tine.

Preferably lock means are provided operable to lock the spindle into said first position.

Preferably the said lock means comprise a lock arm moveable to and from a position wherein movement of the spindle from the first position to the second position is substantially prevented.

Preferably said tightening means comprises a ratchet.

Preferably the shorter said arm has a key way therein and one or more detents are associated with or fixed with respect to one cog said detent or detents being able to move in said key way.

Preferably the ratchet includes or comprises one or more cog and pawl assemblies.

Preferably the release means comprises withdrawal means to withdraw said pawl or pawls from the cog or cogs.

Preferably, the lock ami withdraws as the pawl or pawls are withdrawn from the cog or cogs.

Preferably the withdrawal means comprises a bias member mounting said pawls, arranged so that said biasing member is biased to a position where in said pawls engage the teeth of said 20 cogs.

Preferably the said bias member mounts the lock arm so that when said pawl or pawls are removed from said teeth said arm moves to a position where the movement of said spindle from the first position to the second position can occur.

Preferably said second lock means includes a handle, said second lock means being 25 prevented from allowing said lock arm to be removed from said spindle until the spindle is rotated with respect to the handle. 130704NZB Ps 20050805 1011 NK.doc/CW/nk intellectual property office of n.2. 2 9 JAN 2007 RECEIVED Preferably the spindle cannot be rotated until the lock arm prevents movement of the spindle to the second position.

Preferably the tensioning device comprises a winch.

Preferably the pawl is biased in use towards the cog by gravity.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

One preferred form of the invention will now be described with reference to the accompanied drawings in which.

Figure 1 is a front elevation of a tensioning device according to one preferred form of the invention.

Figure 2 is a partially underneath view of the tension device of Figure 1 in an open 15 configuration.

Figure 3a, 3b & 3c is a side elevation of part of the tension device of Figure 1, is a diagrammatic representation of a spindle and other associated parts for use in the tension devicc of Figure 1, is a diagrammatic cross section through a spindle and spindle supporting parts of the tensioning device, is a diagrammatic cross section of a spindle for use in the invention, is cross sections diagrammatic view through the spindle of an alternative construction, Figures 8, 10, 12, 13 and 14 comprise side elevations of alternative bifurcated members for 25 use in the invention.

Figures 9, 11 and 15 are cross sections of figures 8, 10 and 12 respectively. 130704NZB Ps 20050805 1011 Nk.doc/CVV/nk Figure 4 Figure 5 Figure 6 Figure 7 s - Figure 16 is a front cross section of a winch according to a further preferred form of the invention, Figure 17 is an end elevation of a cog and pawl for use in the winch of Figure 16, Figure 18 is an end elevation of a spool for use in the winch of the embodiment of 5 Figure 16, Figure 19 shows an alternative construction, and Figure 20A and 20B show a further alternative to the constructions in Figures 1 to 15.

In the tensioning device of the embodiment of the invention in Figures 1 to 14 a tensioning devicc in the form of a tie down is provided much of which is relatively standard, for 10 example the tensioning device 1 comprises a frame formed by a pair of side plates 2 and 3 between which a spindle generally indicated at 4 extends.

Associated with the spindle 4 are tightening means and release means.

The tightening means in the preferred form comprise a pair of ratchets each comprising a cog 6 or 7 and pawls 8 or 9 which are biased into engagement with the teeth of the cogs. The 15 pawls may therefore comprise extensions from a plate 10 which is biased towards the position where the pawls 8 or 9 engage the teeth of the cogs 6 or 7, for example, by a spring 12 of known type. The plate 10 may be pulled against the spring pressure by means of a handle 15 which enables the pawls 8 or 9 to be withdrawn from the teeth of the cog 6 or 7 respectively to allow the cogs and therefore the spindle 4 to rotate freely.

In order to rotate the cogs 6 and 7 in the tightening direction, a frame 18 is provided which has further detents 21 and 22 on a plate 23 so that by relative rotation of the plates 20 with respect to the side plates 2 and 3, the cogs 6 and 7 may be rotated. The teeth on the cogs 6 and 7 are shaped so that during this rotation so that they "click" over the pawls 8 and 9. When the device is opened a cam or protrusion 26 on arms 2 and/or 3 pushes back the 25 detents 21 and 22 so pushing plate 23 and releasing the detents 21 and 22 from the cogs 6 and 7. The handle 15 can be firstly pulled back to allow the device to fully open and then released so that pawls 8 and 9 or plate 10 enters slots 27 in the periphery of the plates 20 to hold the device in an open position. 130~04NZB Ps 2005081)5 1011 NK.doc/CWVnk Side plates 2 and 3 may then be rotated with respect to plates 20 by means of a rod 19 spanning plates 2 and 3, for example by holding the plates 20 and rotating plates 2 and 3 along with the rod 19 to and fro. When plates 2 and 3 close onto plates 20 pawls 8 and 9 "click" over the teeth of cogs 6 and 7, but when the plates 2 and 3 open from plates 20 the 5 cogs 6 and 7 are rotated by the pawls 8 and 9 thereby rotating the spindle 4. Detents 21 and 22 work oppositely on cogs 6 and 7 to prevent the spindle 4 from rotating as the plates 2 and 3 close onto plates 20 but allow rotation of the cogs 6 and 7 as plates 2 and 3 open from plates 20.

The cog 7 may be spaced from the side plate 3 by a spacing washer 30, and from the frame 10 member 20 on that side of the construction by further spacing washer 31.

The invention shapes or configures the spindle 4 so that a strap can be positioned therein without the necessity of threading the strap lengthwise of the strap through the slot 40, between bifurcated tines 41 and 42 which form the spindle 4. This may be achieved in a number of ways and for example part of one spindle arm, for example tine 42, or indeed tine 15 41, may be pivotally mounted to the remainder of the device so as to be openable with a suitable latching mechanism or other constructions may be provided.

The intention is to provide access to the slot in the spindle other than by threading lengthwise of the strap. Other constructions could include, a single sided device with a spindle open at one end, with a flange at the open end, or one side frame could pivot outwardly or upwardly 20 or downwardly to provide access to the slit in the spindle, or the spindle could slide outwardly away from one arm to allow access to the slot in the spindle, or one frame arm could move in translational fashion away from the spindle. A further method would be to shape the spindle 4 in the manner shown in Figure 7 to provide a slot 46 with a narrow mouth 47. The strap 48 can be manipulated into the slot 46, for example, by forming the 25 strap 48 to the shape indicated at 49 and releasing the belt within the slot 46. A further particular and preferred method is to provide the tine 42, somewhat shorter than the tine 41, and provide that the spindle is laterally movable in the direction of the arrows 43. Thus with the spindle in the position shown in Figure 1 both tines 41 and 42 span between the frame and can be operated in substantially the known manner.

If however, the spindle is moved towards the left (Figure 1) the arm 42, will eventually reach a position wherein access to the slot 40, can be obtained from the end 45 of the arm 42. The 130704NZB I's 20050805 1011 NK.doc/CW/nk tines 41 and 42 can then be moved towards the right of Figure 1 to in effect close the gap leading into the slot 40.

In order to maintain alignment a key way 50, may be provided into the tine 42, and the detents 32 and 33 become positioned therein. The detents 32 and 33 are formed by turning 5 outwardly tabs extending from the spacers 30 and 31. This substantially ensures that frame parts 3 and 20 as well as the cog 7 and spacers 30 and 31 maintain the correct relative position when the spindle is moved to the left (in Figure 1) to allow entry to the slot. The cogs 6 and 7 are prevented from rotation on spindle 4 in any suitable manner. For example the spindle tines 41 and 42 can pass through separate apertures in the cogs 6 and 7. As the 10 spindle 4 cannot rotate with respect to the cogs 7, and as the detents 32 and 33 substantially prevent rotation of the spindle with respect to the spacers 30 and 31 the detents 32 and 33 are effectively fixed with respect to cog 7.

A pin 54 is desirably provided towards the distal end of the arm 41 to prevent movement of arm 41 too far to the left (in Figure 1).

It will also be apparent that it is necessary to prevent unwanted movement towards the left by the spindle 4 (by reference to Figure 1) to this end a lockmeans is provided which may be formed by an ann 60, which provides a cap 61 which is able to be positioned over the left hand end of the spindle 4 (with reference to Figure 1) and it will also be apparent that this must be able to be withdrawn when required. To this end the arm 60 may be connected to 20 the plate 10, so that the arm 60 is withdrawn when the pawls 8 and 9 are removed from the teeth of the cogs 6 and 7. Accordingly, if handle 15 is pulled upwardly (as shown in Figure 1) the arm 60 will move drawing the cap 61 away from the end of the spindle 4 thereby allowing the spindle 4 to be moved to the left.

Second lock means are provided to substantially prevent accidental movement of the spindle 25 4 along its axis to the open position. Plates 20 carry protrusions 55 and the handle 15 carries lugs 56. The protrusions 55 and lugs 56 are shaped and positioned such that with the plates 2 and 3 closed onto the plates 20 the protrusions 55 engage or about the lugs 56 to substantially prevents the handle 15 from moving to an extent such that the cap 61 is withdrawn from covering (in part) the spindle 4. 130704N/.B Ps 20050805 1011 NK.doc ("W/nk In order to remove the detents 8 and 9 from the slots behind protrusions 57 the handle 15 must be pulled. Cap 61 cannot be pulled away from spindle 4 until the handle 15 is pulled to remove detents 8 and 9 from the slots behind protrusions 57, and the plates 2 and 3 rotated away from plates 20 to an extent the protrusions 55 clear the lugs 56. This allows the cap 61 5 to clear the spindle 4 In reverse if the spindle 4 is in the open position the cap is shaped to substantially prevent the detents 8 and 9 from engaging the teeth on cogs 6 and 7.

Connector 62 assists in holding the arms 2 and 3 together to substantially prevent the construction from falling apart. Fixing devices such as rivets 63 passing through apertures in the arms 2 and 3 fix the connector 62 to the arms 2 and 3.

Referring now to Figures 5 and 6 a stop, such as pin 65 spans the arms 41 and 42 of the bifurcated spindle 4 to prevent movement too far to the left (in Figure 5) and substantially prevents the cog 6, washer 31 and plate 20 from falling from the spindle 4 in use.

Flanges 66 extend outwardly from a plate 67 spanning plates 20. The plates 2 and 3 may 15 each also have flange 68 thereon to increase the rigidity of plates 2 and 3. The flanges 66 are positioned so that they overlay the ends of plates 2 and 3 to substantial prevent spreading of the arms 2 and 3.

An extension 69 of handle 15 extends through an elongated slot in plate 3. A turned lug 90 is positioned on the outside of the plate 3. Should the free end of arm 41 be hit inwardly the force will be transferred to cap 61, through handle 15 to the lug 90 which will strike or abut the plate 3 thus reducing any tendency of the plates 2 and 3 to spread.

If desired the free end of tine 42 can be tapered as shown in Figure 6 to ease entry of tine 42 through the apertures in plate 20, plate 3 and cog 7 as the taper will assist in aligning the various apertures. This is particularly useful as the construction wears in use.

In use the tensioning device would ordinarily be connected to one end of a strap which is engaged for example to part of a truck or lorry or otherwise as it is being used. The strap (not shown) is attached at or adjacent one end to the truck or lorry and passes over a load on the tray of the truck or lorry. The strap is then positioned into the slot 40 to enable the tensioning to occur. To enable this to occur the handle 15 is pulled so that the spindle 4 can 130704NZB Ps 20050S05 1011 NK.dnc.CW/nk movc to the left revealing the free end 45 of the tines 42 between the plates 2 and 3. The strap is then fed in crosswise fashion past the end 45 into the slot 40. Once positioned the spindle then can be returned to the position in Figure 1, the handle released so that the arm 60, covers the left hand end of the spindle 4, and tensioning can then occur by moving the 5 arms 2 and 3 to and fro in known fashion. When it is desired to release the construction the pressure is released in the known manner by pulling on the handle 15 to release the pawls 8 and 9 from the teeth of the cogs 6 and 7. The arms 2 and 3 are rotated in to the open position thus cams 26 or protrusions on plates 2 and 3 will push detents 21 and 22 from cogs 6 and 7 to allow spindle 4 to spin taking the pressure from the strap engaged with the spindle. The 10 arm 61 can also be withdrawn by pulling handle 15 and when the strap is loose the spindle can be moved to the left and the strap withdrawn from the slot 40, in the opposite manner to which it was inserted.

Referring now to Figure 8 and 9 the bifurcated spindle 4 has a pin 54 as before but a brace in the form of a pin 70 with a sleeve 71 thereabout is placed between the tines being positioned 15 in use underneath plate 2. The brace both acts as a stop to prevent movement of the spindle 4 to the left (in Figure 8) beyond the point where the pin 70 and sleeve 71 contacts the outside of the cog 6 and also acts to spread any loads tending to cause the tines 41 and 42 to close one onto the other.

In the construction shown in Figure 10 and 11 the pin 72 is transverse and may fit into recess 20 73 and 74 in tines 41 and 42. The pin 71 acts in the same manner as of the tines 41 and 42 pin 70 and sleeve 71 shown in Figures 8 and 9.

In figure 12 the inner end of slot 40 is thickened as at 78 to achieve the same result as pin 70 and sleeve 71 in Figures 8 and 9.

In the construction of Figures 13, 14 and 15 the pin 70 or 71 is replaced by a pair of spring 25 loaded screws 75 and 76 between tines 41 and 42, which in this embodiment may be independent members. The enlarged head of screws 75 and 76 may be set in recesses 77 and 78 in tine 41 (or 42) and be screwed into tines 42. The screws 75 and 76 may pass through apertures in tines 41. Springs 80 and 81 are positioned about screws 75 and 76 respectively to hold the tines 41 and 42 in a position where any tendency of the tines 41 and 42 to move 30 mutually inwardly, as in Figure 14, the screws 75 and 76 ideally act to maintain the correct relative orientation of the tines 41 and 42. 130704NZB I's 20050805 1011 NK.doc/CW/nk In the construction of Figure 19 a flanged sleeve 150 is provided the bore 151 of the sleeve 150 is irregular in outline, for example being semi-circular so that arm 42 will not rotate in the sleeve 150. The inner flange 152, and outer flange 153, hold the plate 20. cog 7 and plate 3 there between.

In the constructions of Figures 20A and 20B the shorter arm 42 has an aperture 160 at one end 161. The aperture 160 and arm 41 are shaped so that the material defining aperture 160 can slide on the arm 41 but cannot substantially rotate. As can be seen Figure 20A shows the construction in an "open" position and Figure 20B shows the construction in a "closed" position.

Referring now to Figures 16 to 18 a winch 101 is provided which comprises a frame 102 which has a pair of side plates 103 and 104. In the preferred form an intermediate plate 105 is provided. The plates 104 and 105 have apertures into which is placed a spool 106. The spool 106 has end flanges 107 and 108 and a central part 109 which has a pair of apertures 110 and 111 which in the preferred form are in the shape of segments of a circle but which 15 may be of other cross sectional shapes if desired. The end plate 103 also has an aperture at 115 through which a spindle 120 passes. The spindle 120 has a pair of tines 121 and 122 in bifurcated fashion so that tine 121 for example passes through aperture 110 in the spool 106 and 122 passes through the aperture 111. The tine 121 is somewhat longer than the tine 122. The spindle 120 is moveable longitudinally as shown in arrow 125 from the position shown 20 in Figure 16 to a position where the spindle is placed somewhat more to the left of the position shown in Figure 16. A pin or other stop 128 may be provided to prevent movement to the left (as shown in Figure 16) to an extent that would cause the construction to come apart. When in the extreme left position an entrance way into the slot 129 between the tines 121 and 122 is provided so that webbing can be placed therein. In the preferred form the 25 spindle has an aperture 130 through which a jemmy bar or other bar can be placed so that the spindle can be rotated about its longitudinal axis.

In order to allow the rotational spindle 120 to occur in one direction but to be substantially cemented in the other a cog 135 is desirably mounted on the spindle 120 so as to rotate therewith. Simply this could be achieved by providing an aperture in cog 135 and a shaped 30 part of the spindle or more desirably the cog 135 and the spindle 120 are connected together. The cog 135 is associated with a pawl 140 which may be mounted so that it can swing on an axle or pin 141 passing through a suitable aperture in the plate 103 and being provided with I30704N/.B Ps 20050805 1011 Nk.doc'CW/nk an enlarged head for example to substantially prevent unintended removal. The pawl has a first part 143 which engages teeth 144 in the cog to prevent rotation thereof and a second part 146 which overlaps the cog to substantially prevent any movement of the cog away from the position shown in Figure 16. When it is desired to release the spindle the pawl 140 can 5 be swung out of the way so that the part 143 no longer engages the teeth 144 allowing the spindle to rotate. When it is desired to move the spindle to the left (in Figure 16) again the pawl can simply be swung out of the way so that the spindle and cog thereon can be moved on to the left to allow access to the slot 129.

In use the pawl 140, which is biased by gravity, is swung out of the way, and the spindle 120 10 is moved to the left to allow access to slot 129 and strapping can be passed other than lengthwise into the slot 129. The spindle is then returned to the position shown in Figure 16 and the spindle rotated about its longitudinal axis for example utilising the aperture 130. The pawl 140 will maintain the tension in the straps. When it is desired to release the tension the pawl is withdrawn so that the spindle can rotate freely. The strap can then be removed for 15 example by again moving the spindle to the left (in Figure 16).

Thus it can be seen that with reference to Figures 1 to 15 a tensioning device is provided in which the strap can be readily inserted into the slot between the tines of the bifurcated spindle. It is not necessary to feed the strap length wise into the slot 40 and pull it through. Accordingly, the engagement of the strap into the slot between the bifurcated arms of the 20 spindle is more quickly achieved and also it is not necessary to handle a free end of the strap or webbing which may be wet, muddy or otherwise dirty. The strap can be released from the tensioning device in the reverse manner to its engagement, which also saves time. Also the strap can be released without the need to undo any knot made in the strap and provided the strap is sufficiently long the actual length does not affect the use of the tensioning device. It 25 is believed that a substantial time saving can be achieved by the tensioning device of the invention over those currently available on the market. Large frayed ends of a strap do not prevent the strap from being used.

Referring to Figures 16 to 18 it can be seen that a winch is provided in which the strap can also be readily inserted into the slot between the tines of the bifurcated spindle. It is not 30 necessary to feed the strap length wise into the slot 129 and pull it through. Accordingly, the engagement of the strap into the slot between the bifurcated arms of the spindle is more quickly achieved and also it is not necessary to handle a free end of the strap which may be 1307O4NZB Ps 20050805 1011 NK.doc'CW/nk wet, muddy or otherwise dirty. The strap can be released from the winch in the reverse manner to its engagement, which also saves time. Also the strap can be released without the need to undo any knot made in the strap or webbing. Furthermore provided that sufficient length is provided the actual length of strap does not affect the use of the winch.

Large frayed ends also do not prevent use of the strap. It is believed that a substantial time saving can be achieved by the winch of the invention over those currently available on the market.

I30704NZB Ps 20050SD5 1011 Nk.tloeC'W.nk

Claims (7)

1. A tensioning apparatus comprising a frame, a bifurcated spindle providing two tines one of which is longer than the other, the spindle being mounted on the frame for rotational movement thereon and defining a slot between the two tines, tightening means operable to rotate the spindle in a first direction, release means operable to cause or allow the spindle to rotate in the opposite direction, and the spindle being shaped or able to be configured so that in use a strap may be positioned within the slot formed in the bifurcated spindle by movement other than threading the strap lengthwise of the strap through the slot.

2. A tensioning device as claimed in claim 1 wherein the frame has a pair of spaced apart side plates and the spindle being moveable relative to the frame so that the spindle is moveable between a first position wherein both tines extend between the side plates and a second position wherein at least one tine does not extend between the side plates to allow access to the slot from the free end of the shorter tine.

3. A tensioning device as claimed in either one of claims 1 and 2 further including lock means operable to lock the spindle into said first position.

4. A tensioning device as claimed in claim 3 wherein the said lock means comprise a lock arm moveable to and from a position wherein movement of the spindle from the first position to the second position is substantially prevented.

5. A tensioning device as claimed in any one of the preceding claims wherein said tightening means includes a ratchet.

6. A tensioning device as claimed in claim 6 wherein the ratchet includes or comprises one or more cog and pawl assemblies.

7. A tensioning device as claimed in claim 6 wherein the shorter said tine has a key way therein and one or more detents are associated with or fixed with respect to one cog said detent or detents being able to move in said key way. 130704NZB Ps 20050805 1011 NK.doo/CW/nk intellectual property ofrce of im.z. 2 9 JAN 2007 BJLCEiVEn - 14- 9. 5 10. 10 12. 15 13. 20 14. 15. 16. 25 A tensioning device as claimed in either one of claims 6 and 7 wherein the release means comprises withdrawal means to withdraw said pawl or pawls from the cog or cogs. A tensioning device as claimed in claim 6 when dependent on claim 4 wherein the lock arm withdraws as the pawl or pawls are withdrawn from the cog or cogs. A tensioning device as claimed in claim 8 wherein the withdrawal means comprises a bias member mounting said pawls, arranged so that said biasing member is biased to a position wherein said pawls engage the teeth of said cogs. A tensioning device as claimed in claim 10 when dependent on claim 4 wherein the said bias member mounts the lock arm so that when said pawl or pawls are removed from said teeth said arm moves to a position where the movement of said spindle from the first position to the second position can occur. A tensioning device as claimed in either claim 3 or claim 4 wherein second lock means are provided and the lock arm cannot be removed from said spindle to allow said spindle to move to said second position until the second lock means are released. A tensioning device as claimed in claim 12 when dependent on claim 4 wherein said second lock means includes a handle, said second lock means being prevented from allowing said lock arm to be removed from said spindle until the spindle is rotated with respect to the handle. A tensioning device as claimed in claim 4 wherein the spindle cannot be rotated until the lock arm prevents movement of the spindle to the second position. A tensioning device as claimed in any one of claims 1, 2 and 6 to 8 wherein the tensioning device comprises a winch. A tensioning device as claimed in claim 15 when dependent on any claim 7 or claim 8 iased in use towards the cog by gravity. Limited 2 9 JAN 2007 received intellectual property office of n.z. 130704NZB Ps 20050805 1011 NK..doc/CW/nk