GB2548390A

GB2548390A - Fastening tool

Info

Publication number: GB2548390A
Application number: GB1604570.0A
Authority: GB
Inventors: Goddard Alex
Original assignee: British Gas Trading Ltd
Current assignee: British Gas Trading Ltd
Priority date: 2016-03-17
Filing date: 2016-03-17
Publication date: 2017-09-20
Anticipated expiration: 2036-03-17
Also published as: GB201604570D0; GB2548390B

Abstract

The wrench 100 comprises a rotatable member 110; a housing 120; a drive connection 130 for providing a driving torque to drive the rotatable member 110; and a gear arrangement 140-146 for converting the driving torque into rotational movement of the rotatable member 110 and for providing a reduction ratio between the first drive connection 130 and the rotatable member 110. The rotatable member 110 and has a recess 112 for receiving and gripping the nut and slides onto the nut in a direction perpendicular to the axis of rotation of the nut. The rotatable member 110 has a geared outer surface 114. The gear arrangement 140-146 comprises at least two spaced-apart driven pinions 148 for engaging with the geared outer surface 114 of the rotatable member 110 to drive the rotatable member 110. The gear arrangement 140-146 is back-drivable to permit rotation of the rotatable 110 member relative to the housing 120.

Description

FASTENING TOOL

FIELD OF THE INVENTION

The present invention relates to gripping tools. More particularly, the present invention relates to a tool for tightening and loosening nuts.

BACKGROUND OF THE INVENTION

Fastening tools such as spanners (wrenches) or pliers are normally required for gripping and rotating fasteners such as nuts and bolts. A user places the opening of the fastening tool around the nut or bolt and then applies pressure to the handle to rotate the nut/bolt. The handles of fastening tools are often quite long (e.g. 20-40cm) to allow the user to apply sufficient torque to fasten/unfasten the nut/bolt.

These fasteners are sometimes located in small spaces which are difficult to access. It may be difficult, or even impossible, to fit a conventional wrench over a fastener in a confined space. Even if it is possible to fit the opening of the wrench onto a fastener, there may not be enough room to rotate the handle. Ratchet wrenches, which have a socket for fitting over a nut or bolt and a ratcheting mechanism for turning the socket in order to rotate the nut or bolt are also known. A particular problem arises in the case of nuts fitted onto pipework, such as compression fittings or water pumps where conventional socket and ratchet spanners cannot be used and confined access issues are often greater.

SUMMARY OF THE INVENTION

The present invention seeks to provide an improved tool for tightening or loosening rotatable nuts.

Aspects of the invention are set out in the independent claim and preferred features are set out in the dependent claims.

There is described herein a tool for tightening or loosening a rotatable nut, the tool comprising: a rotatable member for rotating the nut about a first axis, the rotatable member having: a recess for receiving the nut, the recess being shaped for sliding onto the nut in a direction perpendicular to the first axis and gripping the nut to rotate with the rotatable member; and a geared outer surface; a housing for supporting the rotatable member and constraining the rotatable member to rotate about the first axis within the housing; a first drive connection for providing a driving torque to drive the rotatable member; and a gear arrangement for converting the driving torque into rotational movement of the rotatable member about the first axis and for providing a reduction ratio between the first drive connection and the rotatable member, the gear arrangement comprising at least two spaced-apart driven pinions for engaging with the geared outer surface of the rotatable member to drive the rotatable member; wherein the gear arrangement is back-drivable to permit rotation of the rotatable member relative to the housing to cause rotation of the first drive connection.

By providing a tool with a rotatable member which can be slid onto the nut from a direction perpendicular to the axis of rotation of the nut, it is possible to engage a nut in a confined space, particularly a nut on a pipe or where there is little room in the direction along the axis of rotation. Providing two spaced-apart pinions, or gears, means the rotatable member can be driven at all points of rotation, even when one of the pinions cannot engage the outside of the rotatable member due to the position of the recess. The back-drivable mechanism allows for easy removal of the tool once the tightening or loosening of the nut has been completed. In particular, when the tightening or loosening of the nut is accomplished in a fractional number of rotations, the recess in the rotatable member will be enclosed by the housing and the tool cannot be slid straight off the nut from the direction in which it was slid onto the nut. By providing a back-drivable gear arrangement it is possible to rotate the housing about the rotatable member so that the tool can be more easily removed from the nut by rotating it manually without needing to actuate the drive connection to position the recess so the tool can be slid off the nut. The drive connection may be a standard socket (e.g. a % inch or 3/8 inch socket) or other drive connection for connecting the tool to a powered or manual driving tool, such as a splined or hexagonal shaft.

Preferably, the first drive connection is configured to rotate about a second axis, substantially perpendicular to the first axis. This facilitates access, particularly when using the tool in small spaces.

Preferably, the first drive connection is coupled to the gear arrangement via a bevel gear. Advantageously, a bevel gear converts rotation about one axis into rotation about a different, non-parallel axis. This allows the driving torque to be provided as rotation about an axis which is not parallel to the first axis, which means the tool can be used even where space around the nut is limited. A bevel gear arrangement can be back-driven, unlike e.g. a worm gear arrangement. Normally first and second bevel gears are required to allow the conversion of rotation about one axis into rotation about a different, non-parallel axis.

In some embodiments, the tool further comprises a second drive connection configured to rotate about an axis substantially parallel to the first axis. This allows for flexibility In the direction from which the tool is driven, meaning it can be used in a variety of situations. Advantageously, the first and second drive connections, which allow the tool to be driven from different directions, are arranged to transmit drive from a common point. This allows for an even distribution of force around the tool, regardless of the direction (or drive connection) from which it is driven.

Alternatively, the drive connection configured to rotate about an axis substantially parallel to the first axis may be provided instead of the drive connection configured to rotate about an axis perpendicular to the first axis.

Preferably, the rotatable member or an insert therein is removable to permit interchange of the rotatable member or insert for a replacement rotatable member or insert with a different sized recess to allow the tool to be used with a variety of different sized nuts. This means only one tool Is required for use on nuts of different sizes.

Preferably, the rotatable member or insert can be removed from the housing substantially along the first axis. This allows easy removal of the rotatable member from the housing because the teeth of the rotatable member can slide out from the teeth of gear arrangement along the first axis.

Preferably, the tool further comprises a removable resiliently deformable clip for securing the interchangeable rotatable member or insert within the housing, which is a simple and easy-to-use means for allowing the clip to be removed from the tool. The clip can engage with the housing, and to change the rotatable member or insert a user can apply pressure to the clip to disengage it from the housing and allow the rotatable member or insert to be removed.

Preferably, the clip comprises a low friction base for contact with the rotatable member or insert to secure the rotatable member or insert within the housing while not impeding the rotation.

Preferably the rotatable member is configured to allow an insert to slide into the rotatable member, which provides an easy insertion method.

Preferably the rotatable member has a groove to allow the insert to slide into the rotatable member, in order to help retain the insert in the rotatable member.

In one embodiment, the insert can be inserted into the rotatable member in a direction substantially perpendicular to the first axis.

Preferably, the removable insert is magnetically retained within the recess in the rotatable member. This is a simple and effective way of ensuring the rotatable member or insert is retained securely.

Preferably, the removable member or insert is retained within the recess in the rotatable member by means of a clip or catch.

Preferably, the rotatable member or insert is retained within the recess in the rotatable member by means of a spring-loaded mechanism.

Preferably, the insert (or rotatable member) comprises a protrusion for removal of the insert from the recess of the rotatable member (or the housing). This allows easy and quick removal of the insert (or rotatable member).

Preferably, the geared outer surface extends substantially continuously about the circumference of the rotatable member for between 240 degrees and 290 degrees, preferably about 270 degrees. By extending the geared outer surface around a substantial portion of the rotatable member, the portion of rotation in which one or more of the driven pinions (or driving gears) does not engage the geared outer surface is reduced, while providing a recess that can fit a large nut, without needing an excessively large rotatable member.

Preferably, the width of the recess is between about 55% and 80% of the nominal outside diameter of the rotatable member, preferably around 70%. With this sized recess the angular size of at the circumference of the rotatable member is between 75 degrees and 110 degrees, preferably around about 90 degrees. By increasing the width of the recess, or opening, it is possible to use the tool with a larger nut, while not providing an excessively large tool (which may not fit into confined spaces). The maximum size of the recess depends on the spacing of the driven pinions, as in order to rotate there must always be at least one driven pinion in contact with the rotatable member at any given time. The width here is taken to be the distance between opposing sides of the recess at the circumference of the rotatable member. The nominal outside diameter is the largest diameter across the rotatable member, i.e. the diameter measured at the outer protrusions of the geared outer surface.

Preferably, the gear arrangement is substantially in a plane perpendicular to the first axis. By providing the gear arrangement in a plane, it is easier to access nuts in small spaces.

Preferably, the two spaced-apart driven pinions for engaging with the geared outer surface of the rotatable member are spaced apart by at least 80 degrees, preferably around 90 degrees, more preferable by more than 90 degrees.

Preferably, the driven pinions are spaced apart by more than the recess in the rotatable member, so that the rotatable member can be driven by at least one pionion at all points in its rotation.

In one embodiment, the rotatable member or insert therein is configured to receive a nut of diameter between 50mm and 100mm. In another embodiment, the rotatable member or insert therein is configured to receive a nut of diameter between 18mm and 26mm. This tool may be particularly useful for large nuts as it provides means for attaching a power tool for rotating the nut.

Preferably, the housing includes one or more idler gears for engaging with the geared outer surface of the rotatable member to guide the rotatable member into the housing. This allows smoother rotation in the housing, particularly with a larger recess.

Preferably, at least one of the drive connections comprises a socket for coupling to a tool to provide the driving torque, which is a simple and efficient way of driving the tool, particularly in confined spaces, e.g. a power tool may be particularly advantageous where space to allow sufficient torque to be applied by a manual tool may be restricted.

Preferably, at least one of the drive connections is secured to a drive shaft having a hexagonal cross-section, the drive shaft being arranged to receive a power tool to provide the driving torque. For example, the drive shaft may comprise a hexagonal attachment to receive a regular drill shank of diameter 6mm (1/4 inch) to 13mm (1/2 inch). Preferably the hexagonal cross-section will have a diameter of between 6mm and 13mm, but drill shank sizes to fit other common drill sizes are also envisaged. Thus the tool can easily be used in conjunction with power tools which are in common use. This removes the need to provide a power source in the tool, which would increase the complexity and cost of the tool. The drive shaft may also be arranged to receive a handle to allow the user to manually drive the gear arrangement. This allows the tool to be used without a power tool.

Preferably, the reduction ratio is at least 2:1, preferably at least 3:1, which provides mechanical advantage to allow a larger torque, or turning force, to be applied to the nut.

There is also described herein a tool kit comprising: a tool as described above, in which the rotatable member or insert is removable to permit Interchange of the rotatable member or insert for a replacement rotatable member or insert with a different sized recess to allow the tool to be used with a variety of different sized nuts; and at least two replaceable replacement rotatable members or inserts with different sized recesses to allow the tool to be used with a variety of different sized nuts.

Although discussed in terms of rotating a “nut”, the device can of course equally be used to rotate a corresponding bolt or other rotatable fastener.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only and with reference to the accompanying drawings, in which:

Figure 1 illustrates a top view of a tool according to a first embodiment;

Figure 2 illustrates a side view of the tool of Fig.1;

Figure 3 illustrates a perspective view of the tool of Fig.1;

Figure 4 illustrates an exploded view of the tool of Fig.1;

Figure 5 illustrates a cross-sectional view of a tool according to an alternative embodiment;

Figure 6 illustrates a top view of the tool of Fig.5; and

Figure 7 illustrates a perspective view of the tool of Fig. 5.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figure 1, a tool 100 for tightening and loosening a rotatable nut will now be described. The tool 100 comprises a housing 120, which holds a rotatable member 110. The rotatable member 110 has a recess 112 for receiving a rotatable nut. The housing 120 also has a recess to allow the rotatable member to receive a nut. The tool 100 also comprises a drive shaft 130 for providing a driving torque for driving the rotatable member 110. In use, the rotatable member 110 is slid onto the nut and grips the nut. The rotatable member 110 can rotate about an axis perpendicular to the plane of the page (shown by arrow 160) in order to tighten or loosen the nut.

The rotatable member 110 can be removed from the tool along an axis perpendicular to the page. The rotatable member 110 is secured within the housing 120 by a clip 150, which sits on top of the rotatable member 110 to secure It In place.

Figure 2 shows a side view of the tool 100 of Figure 1, showing the housing 120 and the drive shaft 130. The drive shaft 130 has a hexagonal portion 132 having a hexagonal cross-section, for easily attaching to a power drill or screwdriver. The power (typically electric) drill can provide the driving force to rotate the rotatable member 110. This allows automatic provision of the driving force. In addition it may be possible to provide more force in a relatively small space compared to e.g. a conventional spanner.

Normally where a large amount of rotational force is required, a longer handle is provided so that the same force creates a larger moment for rotating the nut. However, where there is not enough room to rotate a long handle around the nut, the presently described tool 100 can still be used because the tool does not need to be rotated about the nut.

Figure 3 shows a perspective view of the tool 100 of Figure 1. The recess 112 allows the tool to be slid onto a nut in the direction shown by arrow 180, which is perpendicular to the axis of rotation of the nut and rotatable member 110 (about arrow 160). This allows the tool 100 to be used even where there is very little space around the nut, particularly where it is not possible to slide a spanner onto the nut from a direction along the axis of rotation of the nut.

The direction of rotation of the drive shaft 130 is shown by arrow 170. The axis of rotation of the drive shaft 130 (about arrow 170) is in a plane perpendicular to the axis of rotation of the rotatable member 110 (about arrow 160). This means the tool 100 takes up very little space in a direction along the axis of rotation of the nut and so can be easily used in confined spaces.

Figure 3 also shows end projections 152 of the clip 150, which extend above the plane of the clip 150. The clip 150 can removed to allow the rotatable member 110 to be removed from the housing 120. The clip 150 functions like a circlip. The clip 150 has side protrusions (not shown in Fig.3) which each engage with a recess 126 in the housing 120 to secure the rotatable member 110 in place. The clip 150 is made of a resiliently deformable material, normally plastic, and the protruding ends 152 can be squeezed together by a user in order to disengage the side protrusions from the recesses 126.

Once the clip 150 has been removed, the rotatable member 110 can be removed in a direction along the axis of rotation of the rotatable member 110. This means the teeth along the circumference of rotatable member 110 can simply be lifted out from the gear arrangement with which they interact This provides a good way for keeping the rotatable member 110 securely in place in the housing 120, but allowing easy removal.

The rotatable member 110 can be replaced by another rotatable member with a recess of a different size for fitting onto a nut of a different size. Generally, rotatable members are sized to fit nuts of ¾ inch (19.05mm) in diameter, or 1 inch (25.4mm) in diameter. However, the tool may be suitable for use with nuts of 50mm to 100mm in diameter.

Figure 4 shows an exploded view of the tool 100 of Fig. 1. A gear arrangement 140, which sits within the housing 120 is shown. The gear arrangement 140 is driven by the rotation of the drive shaft 130. At the end of the drive shaft 130 is a first bevel gear 142, which meshes with a second bevel gear 144 in order to convert the rotation of the drive shaft 130 into a rotation about an axis parallel to the rotational axis of the nut.

Advantageously, the bevel gear arrangement allows the gear arrangement to be back-driven so that the housing 120 can be rotated about the rotatable member 110. When the rotatable member 110 reaches the end of its rotation (e.g. when the nut is fully tightened), the recess 112 may be facing towards the housing 120, so that the tool cannot slide off the nut in the direction from which it came. If it is impossible to remove the tool along the axis of rotation of the nut, a back-drivable gearing arrangement means that the housing 120 can be rotated about the rotatable member 110 until the recess 112 is in such a position with respect to the housing 120 that the tool 100 can be slid sideways off the nut (i.e. along a direction perpendicular to the axis of rotation of the nut).

The second bevel gear 144 is fixed to a central pinion 145, so that the central pinion 145 rotates when the drive shaft 130 is rotated. The teeth of the central pinion 145 mesh with the teeth of two intermediary gears 143, which in turn engage with two driven pinions 148. The outer circumference of the rotatable member 110 has a geared outer surface 114, with which the driven pinions 148 engage, to cause the rotatable member 110 to rotate.

Two idler gears 146 are positioned one either side of the recess in the housing. These idler gears 146 engage with the geared outer surface of the rotatable member 110 and guide the rotatable member within the housing.

Where possible, the gears are standard spur gears.

It can be seen that the housing 120 comprises a top portion 124 and a bottom portion 122. The housing 120 is made of reinforced plastic and has snap attachments to hold the gear arrangement 140 together permanently. Alternatively, the housing can be formed of metal (e.g. chrome vanadium steel), which allows the tool to function more effectively and with higher forces.

The clip 150 has a low friction plastic base 154 for contact with the rotatable member 110 to allow the rotatable member 110 to rotate easily within the housing 120.

When the housing is formed of metal, it may advantageously be manufactured by drop forging, preferably followed by milling. For example, computer numerical control (CNC) milling may be used. Thus, a very strong grain structure can be achieved within the metal. Product information and logos may also be located on the housing as part of the manufacture process.

Figure 5 shows a cross-sectional view of an alternative embodiment of a tool 500 for tightening and loosening a rotatable nut. The tool 500 has a housing 520 and a rotatable member 510 with a recess for receiving a nut. The tool 500 of Figure 5 differs from the tool shown In Figures 1 to 4, in that there is an additional drive connection 535, located perpendicular to a first drive connection 530. The first drive connection 530 is coupled to a gear arrangement via a first bevel gear 542 and a second bevel gear 544. The first drive connection 530 comprises a % inch socket built into the first bevel gear 542 and the additional drive connection 535 comprises a % inch socket built into the second bevel gear 544. The drive connections 530, 535 are compatible with a number of different tools, Including torque wrenches and power drills to meet specific user requirements.

The bevel gears 542, 544 are arranged to allow power to be transmitted through a 90 degree angle, so that the tool can be driven from the side (i.e. from a direction perpendicular to the axis of the rotation of the rotatable member).

The first drive connection 530 allows the tool 500 to be driven by rotation around an axis perpendicular to the axis of rotation of the rotatable member (and therefore the nut). The additional drive connection 535 allows the tool 500 to be driven by rotation about an axis parallel to the axis of rotation of the rotatable member (and therefore the nut). The rotatable member 510 can be driven by either connection (i.e. from above or from the side), and this flexibility in the angle/direction from which the tool is driven can allow easier access in small, confined spaces. The user may choose one or other direction depending on the use case and environment requirements.

Figure 6 shows a top view of the rotatable member 510 and the gear arrangement of the tool 500 of Figure 5. In use this view would be obscured by the tool housing. The rotatable member 510 has a recess 512 for receiving a nut. As in the embodiment of figures 1 to 4, tool 500 comprises two driven pinions 548 which engage with the geared outer surface of the rotatable member 510 to cause the rotatable member 510 to rotate. In the embodiment of Figure 6, the second bevel gear 544 also has a further gear surface that interlocks with the geared outer surface of rotatable member 510 to transfer rotation. This has the advantage that the rotatable member is driven in three places so that even when one driven pinion is disengaged due to the recess 512, for much of the time the rotatable member is still driven by two gears.

Each of the driven pinions 548 are connected to the second bevelled gear 544 by three intermediary gears 543. The intermediary gears 543 are each smaller than the driven pinions 548 and the bevelled gear 544, which minimises the size of the tool 500. This allows the tool to be used in small spaces, which are hard to access.

There are also provided two idler gears 546, one on each side of the housing recess. The idler gears 546 engage with the geared outer surface of the rotatable member 510 to guide the rotatable member 510 within the housing.

The internal mechanism has been developed to optimise space requirements, to allow it to be used in small locations, and to minimise the number of different sized gears required. A roller 550 is located on a pin under each of the driven pinions 548 and the idler gears 546. Two rollers 552, each on a pin, are also located around the edge of the rotatable member 510 between the driven pinions 548 and the idler gears 546. These rollers 550, 552 support the rotatable member 510, helping to hold it in place and to rotate smoothly.

Figure 7 shows a perspective view of the tool 500 of Figures 5 and 6 with the top housing removed so that the gear arrangement is visible. A nut 10, which can be rotated by the tool 500, is also shown.

An insert 560 is shown, which can be slid into the rotatable member 510 to allow the tool 500 to fit nuts of different sizes. The insert 560 has a recess 566, which is sized to shape nut 10. The insert 560 has a projection 562, which can be slid into a groove 564 on the inside of the recess of the rotatable member 510, which helps to hold the insert 560 in place. The insert 560 is slid into the rotatable member 510 along a direction in the plane of the rotation of the rotatable member 510.

Different sized inserts can be provided to allow the tool 500 to be used with nuts of different sizes.

Any system feature as described herein may also be provided as a method feature, and vice versa. As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure. Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to system aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination. It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently or in other combinations.

The above embodiments and examples are to be understood as illustrative examples. Further embodiments, aspects or examples are envisaged. It is to be understood that any feature described in relation to any one embodiment, aspect or example may be used alone, or in combination with other features described, and may also be used in combination with one or more features of any other of the embodiments, aspects or examples, or any combination of any other of the embodiments, aspects or examples. Furthermore, equivalents and modifications not described above may also be employed without departing from the scope of the invention, which is defined in the accompanying claims.

Claims

CLAIMS:

1. A tool for tightening or loosening a rotatable nut, the tool comprising: a rotatable member for rotating the nut about a first axis, the rotatable member having a recess for receiving the nut, the recess being shaped for sliding onto the nut in a direction perpendicular to the first axis and gripping the nut to rotate with the rotatable member and a geared outer surface; a housing for supporting the rotatable member and constraining the rotatable member to rotate about the first axis within the housing; a first drive connection for providing a driving torque to drive the rotatable member; and a gear arrangement for converting the driving torque into rotational movement of the rotatable member about the first axis and for providing a reduction ratio between the first drive connection and the rotatable member, the gear arrangement comprising at least two spaced-apart driven pinions for engaging with the geared outer surface of the rotatable member to drive the rotatable member; wherein the gear arrangement is back-drivable to permit rotation of the rotatable member relative to the housing to cause rotation of the first drive connection.

2. A tool according to claim 1, wherein the first drive connection is configured to rotate about a second axis, substantially perpendicular to the first axis, preferably wherein the first drive connection is coupled to the gear arrangement via a bevel gear.

3. A tool according to claim 2, further comprising a second drive connection configured to rotate about an axis substantially parallel to the first axis.

4. A tool according to any preceding claim, wherein the rotatable member or an insert therein is removable to permit interchange of the rotatable member or insert for a replacement rotatable member or insert with a different sized recess to allow the tool to be used with a variety of different sized nuts.

5. A tool according to claim 4, wherein the rotatable member or insert can be removed from the housing substantially along the first axis.

6. A tool according to claim 4 or 5, further comprising: a removable resiliently deformable clip for securing the interchangeable rotatable member or insert within the housing.

7. A tool according to claim 6, wherein the clip comprises a low friction base for contact with the rotatable member or insert.

8. A tool according to any of claims 4 to 7, wherein the rotatable member is configured to allow a removable insert to slide into the rotatable member.

9. A tool according to claim 8, wherein the rotatable member has a groove to allow a removable insert to slide into the rotatable member.

10. A tool according to any of claims 4 to 9, wherein the insert can be inserted into the rotatable member in a direction substantially perpendicular to the first axis.

11. A tool according to any of claims 4 to 10, wherein the removable insert is magnetically retained within the recess in the rotatable member.

12. A tool according to any of claims 4 to 11, wherein the rotatable member or insert is retained within the housing or recess in the rotatable member by means of a spring-loaded mechanism.

13. A tool according to any of claims 4 to 12, wherein the insert comprises a protrusion for removal of the insert from the recess of the rotatable member.

14. A tool according to any preceding claim, wherein the geared outer surface extends substantially continuously about the circumference of the rotatable member for between 240 degrees and 290 degrees, preferably about 270 degrees.

15. A tool according to any preceding claim, wherein the width of the recess is between 57% and 80% of the nominal outside diameter of the rotatable member, preferably around 70%.

16. A tool according to any preceding claim, wherein the gear arrangement is substantially in a plane perpendicular to the first axis.

17. A tool according to any preceding claim wherein the two spaced-apart driven pinions for engaging with the geared outer surface of the rotatable member are spaced apart by at least 80 degrees, preferably around 90 degrees, more preferably by more than 90 degrees.

18. A tool according to any preceding claim, wherein the rotatable member is configured to receive a nut of diameter between 50mm and 100mm.

19. A tool according to any preceding claim, wherein the rotatable member is configured to receive a nut of diameter between 18mm and 26mm.

20. A tool according to any preceding claim wherein the housing includes one or more idler gears for engaging with the geared outer surface of the rotatable member to guide the rotatable member within the housing.

21. A tool according to any preceding claim, wherein at least one of the drive connections comprises a socket for coupling to a tool to provide the driving torque.

22. A tool according to any preceding claim wherein at least one of the drive connections is secured to a drive shaft having a hexagonal cross-section, the drive shaft being arranged to receive a power tool to provide the driving torque.

23. A tool according to any preceding claim wherein the reduction ratio is at least 2:1, preferably at least 3:1.

24. A tool kit comprising: a tool according to any of claims 4, or claims 5 to 23 when dependent on claim 4; and at least two replaceable replacement rotatable members or inserts with different sized recesses to allow the tool to be used with a variety of different sized nuts.

25. An apparatus substantially as hereinbefore described In relation to the Figures.

26. A method substantially as hereinbefore described in relation to the Figures.