GB2229949A - Band wrench - Google Patents

Abstract

A wrench to apply a torque to a body, particularly a body in a confined position, comprises a spool 2, rotatably mounted inside a frame 1, and a band 3, one end of which is anchored to the spool, the other end of which is attached to a point 4 of the frame radially spaced from the axis 5 of the spool. The band is made from a strip of material which is flexible in one direction but rigid in the other directions, and is of length suitable to wrap around a body 7. Rotation of the spool inside the frame first tightens the band around the body and then applies a torque to the body. <IMAGE>

Description

Band Wrench.

The invention relates to a device to be used to apply a torque to a body, particularly when the body is in a confined position.

A particularly common problem is the removal of an oil filter which has become fast on its screw mounting, the filter being usually positioned in a somewhat inaccessible part of a car engine. Conventional chain wrenches are equipped with a chain which is passed around the filter body and hooked onto a handle. The handle, which is long enough to provide sufficient leverage, is then pivoted around the filter body to first tighten the chain, and then provide the torque to rotate the body. A problem with such a device is that the handle may be too long to be confortably manipulated around the filter body in the confines of the engine bay. Also, the chain is prone to slip, causing unexpected motion of the handle, which may result in damage to the operator's hand.Garage mechanics faced with the problem of removing an oil filter often resort to puncturing the filter casing with a screwc?rriver, which is then used as a torque wrench. This leads to obvious problems of oil spillage and may damage the scretrdriver.

The present invention provides a device for applying a torque to a body, comprising a frame, a spool rotatable about its axis relative to the frame, and a band, one end of which is anchored to the spool, the other end of which is attachable or attached to the frame at a point radially spaced from the axis of the spool, the band being of length suitable to be passed around a body so that rotation of the spool first tightens the band around the body and then applies a torque to the body.

Preferably the spool is equipped with means for engagment with a turning tool, for example a spigot of a conventional ratchet wrench. The rotatable tool may be operated at some distance from the device using conventional extension attachments.

The band is preferably made from a strip of inextensible material which is flexible in one direction but rigid in the other directions, for example a flat strip of spring steel.

It is a particular advantage that once urund from the spool, around which the band is coiled for storage, the spring steel band forms a self-supporting arc which can be easily slipped around a body. It is also important that the band is of a material strong enough to withstand the stress of tightening around the body, and applying a torque to the body.

The frame is preferably made of sheet metal, and the spool of metal or plastics material.

Perferably there is means, for example, a row of teeth, disposed along the edge of the frame, to engage and grip the side of the body when the spool is rotated to apply the torque to the body.

An embodiment of the invention will now be described by way of example with reference to the following drawings, of which: Figure 1 shows a perspective view of a device according to the invention; Figure 2 shows a detail of the device of Figure 1 showing one method of anchoring the band to the spool; Figure 3 shows a modification of the device of Figure 2 showing an alternative method of anchoring the band to the spool.

Referring to Figure 1, this shows a frame 1, in which is rotatably mounted a spool 2, around which there is wound a band 3. One end of the band is anchored to the spool, the other end is attached to the frame at a point 4 radially spaced from the axis 5 of the spool. In the centre of the spool there is a socket hole 6 suitable to take a conventional spigot of a ratchet wrench. A square spigot will fit the socket shown. The figure shows the device placed against the side of a cylindrical body 7. There is a row of teeth 8 disposed along the edge of the frame between the part of the frame housing the spool and the point of attachment of the end of the band to the frame.The teeth engage the side of the body to grip the body and prevent the device from slipping as the band is tightened around the body by rotation of the spool, and as further rotation of the spool applies the torque to the body.

The frame is made of a single shaped sheet of metal which is bent over into a U-shape to enclose the spool. At the point of attachment 4 of the end of the band to the frame the two sides of the frame are held together by a rivet 14. The end of the band 3 is bent around the rivet 14 to form a sleeve 15, which is held in place by riveting the end to the band itself at 16. The frame has two aligned circular openings 17, which receive raised circular areas 18 on opposite sides of the spool, these raised areas forming bearings for rotation of the spool in the frame. A square socket hole 6 passes axially through the spool to allow engagment with the spigot of a conventional ratchet wrench.

Figure 2 shows one method for anchoring the end of the band onto the spool. The band is bent to follow the shape of a recess 9 in the edge of the spool. The recess is shaped to widen out from its entrance in the edge of the spool so that once the band has been inserted, from the flat face of the spool, it is locked in position. A pin 10 provides added security to prevent the band from straightening out under tension. The band is anchored in positon in the spool prior to assembly of the spool within the frame.

Figure 3 shows an alternative way of securing the end of the band to the spool. The band is bent to conform to the shape of a shallow recess 11 and is held in place by a screw 12, fitted through a hole in the band and inserted into a screwthread hole in the edge of the spool.

When not in use, the band is wound around the spool, and it is desirable that the dimensions of the spool and frame are such that the band may be stored within the overall dimensions of the frame. A web portion 13 of the frame which joins the two side portions of the frame keeps the band in close contact with the spool.

In operation the band is manually uncoiled from the spool and placed around the body to which the torque is to be applied, with the device in the appropriate orientation so that the band is tightened when the spool is rotated in the same direction in which it is desired to turn the body. Figure 1 shows the device in the orientation for turning a body anticlockwise as viewed from above. A spigot is inserted into the socket and turned to rotate the spool and thus tighten the band around the body. Further rotation of the spool will provide the tore to trove the body, the row of teeth gripping the side of the body and preventing the device from slipping.

Because of the small size of the device it may be easily located at a suitable position around the body. The spool may be rotated by a ratchet wrench operated at some distance from the body, where there is more room to manoeuvre the handle of the wrench, by using conventional extension attachments.

Because of this and because of the small size of the device, there is less likelihood of the device interfering with other objects around the body when the device and body rotate together. The device can therefore be used in even the most confined spaces.

It is an advantage of the device according to the invention that it may be used to apply a torque to a variety of sized bodies. Variations in the overall diameter of the body may be acoommodated by the action of winding excess length of band material onto the spool, until the band is tight around the body. For example, a device incorporating a suitable length of band can be used to cater for both commonly available sizes of oil filter; those of diameter 75run and 95mm.

Although the invention is particularly useful for the removal of oil filters, it will be appreciated that the invention could be used to apply a torque to any body around which a band could be placed. It may for example be used by disabled people for unscrewing lids from jars. In this instance the device may be fitted with its own handle for rotating the spool, the type of handle fitted being dictated by the level of dexterity of the individual. For example a butterfly key handle could be attached to the spool.

Claims (7)

1. A device for applying a torque to a body, comprising a

frame, a spool rotatable about its axis relative to the frame, and a band, one end of which is anchored to the spool, the other end of which is attachable or attached to the frame at a point radiaily spaced from the axis of the spool, the band being of length suitable to be passed around a body, so that rotation of the spool first tightens the band around the body and then applies a torque to the body.

2. A device according to claim 1, wherein the spool is equipped with means for engagment with a turning tool.

3. A device according to claim 2, wherein the means for engagament with a rotatable tool comprises a socket for accepting the spigot of a conventional ratchet wrench.

4. A device according to claim 1, 2 or 3, wherein the band is made from a strip of material, which is flexible in one direction but rigld in the other directions, and which is capable of forming a self-supporting arc which can easily b slipped around a body.

5. A device according to claim 4, wherein the band comprises a flat strip of spring steel.

6. A device according to any of the above claims, wherein there is means disposed along the edge of the frame to engage and grip the side of the body.

7. A device substantially as hereinbefore described, with reference to the accompanying drawings.