GB2108029A

GB2108029A - A tool for rotationally secured fasteners

Info

Publication number: GB2108029A
Application number: GB08230897A
Authority: GB
Inventors: Arthur Kenneth Cragg
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-10-30
Filing date: 1982-10-27
Publication date: 1983-05-11
Also published as: GB2108029B

Abstract

The tool has an elongate hollow body (12, 13) rotatably mounting a drive sprocket (26) at one end and a driven sprocket (21) at the other end, both housed within the body. A continuous chain (28) engages the sprockets. The drive sprocket has a formation (27) accessible at the exterior of the body for receiving a handle to rotate the drive sprocket and the other sprocket (21) has a formation (22, 23) for mounting a spanner head or bit. A pawl (30) locks the chain against movement in either selected direction. The tool bit or spanner head can be operated by using the body as a lever, or by rotating the drive sprocket. <IMAGE>

Description

SPECIFICATION A tool for rotationally secured fasteners This invention relates to a tool for rotationally secured fasteners, such as screw fasteners.

It is often necessary to secure or release such fasteners in positions which render rotation of a tool engaged with the fastener difficult. This may be due to poor visibility, problems of access for a hand or arm, or due to obstructions limiting rotational movement of the tool to a small arc.

The present invention provides a tool which reduces this problem.

In accordance with this invention, there is provided a tool comprising an elongate body, engagement means rotatably mounted adjacent one end of the body for engagement with a rotational fastener or a fastener-engageable accessory, drive means rotatably mounted adjacent the other end of the body, and transmission means between the drive means and the engagement means, so that rotation of the drive means can effect rotation of the engagement means.

The engagement means may comprise a socket for engaging a tool head such as a spanner head or screwdriver head, or the engagement means may be defined by a tool head.

The drive means may mount a handle, or be adapted to mount a handle to facilitate rotation thereof.

The transmission means may comprise gearing, but it is preferred that transmission is provided by a continuous band between the drive means and the engagement means in positive driven and driving connections therewith.

In the preferred embodiment, a pawl and ratchet arrangement is provided in association with the engagement means to permit alternative use of the tool as a ratchet lever.

Reference is now made to the accompanying drawings, wherein the sole Figure is an exploded perspective view of a tool according to the invention.

The tool may bs used as a ratchet lever and the appropriate parts for this purpose are described first.

The tool comprises an elongate hollow body of shallow depth comprising upper and lower body shells 12, 13. Each shell is adjustable in length and comprises two slidably interengaged parts 1 2a, 1 2b and 1 3a, 1 3b, one part of each shell having a iongitudinal slot 1 2c, 1 3c which aligns with an aperture 1 2d, 1 3d in the other part of the shell. By this arrangement fastening means engaged in the apertures 1 2d, 1 3d can secure the parts of each shell in different relatively adjusted positions.

Each shell is formed adjacent each end with a circular-section dished part, defining a bearing 14a, 15a and 14b, 14c.Thetwo shells can be secured together, by fasteners engaged in apertures 16, so that each bearing 1 4a, 1 spa of one shell is axially aligned with a corresponding bearing 14b, 1 56 of the other shell.

One set of bearings 1 Sa, 1 Sb, rotatably mounts a spigot 20, which circumferentially carries a sprocket 21. An axially projecting formation 22 is also carried by the spigot 20 and has the external form to mount a socket spanner head, e.g. the square-section shown. The formation also has a socket 23 for receiving a bit as an alterantive to the spanner head. The formation projects through a hole in one of the bearings 1 5a. The spigot 20 can be locked against rotation, in a manner to be described and this allows the body 12, 13 to be used as a lever for use in turning a socket spanner head.

The other set of bearings 1 4a, 1 4b rotatably mounts a second spigot 25, which circumferentially carries a second sprocket 26.

The spigot has a non-circular section axial aperture 27 therethrough for receiving a drive handle (not shown). The aperture 27 is accessible by the handle through holes in both of the bearings 14a, 14b.

A transmission means in the form of a continuous chain 28 engages with the two sprockets 21, 26, so that rotation of the second spigot 27 causes rotation of the first spigot 20 and hence of a bit or spanner head carried by the formation 23. This permits operation from a remote location, so that obstacles to use of conventional tools can be avoided.

A pawl 30 is rotatably mounted on the fastening means 31, which secures the shells together. The pawl can engage with either of two opposite runs of the chain 28 in a ratchet-like manner. When engaged with one run, rotation is prevented in one direction and vice versa; e.g. as illustrated, the chain 28 is prevented from movement in a clockwise direction, but can move in an anticlockwise direction. The pawl can be held in either selected engagement position and also in a neutral position. The pawl is rotatably mounted on a pin 31 and a resilient selector member 33 is mounted on the pin externally of the casing. The member has ramp surfaces 34 which can engage with walls of an indentation 35. The resilience of the member permits jamming of the ramp surfaces 34 against the walls of the depression to hold the pawl in either operative position.

The pawl may, alternatively, engage with the sprocket 21 instead of the chain 28 and springbiasing means may be used for the pawl.

The body length is adjustable, as described above, to permit adjustment of the tension on the chain.

Claims

1. A tool comprising an elongate body, engagement means rotatably mounted adjacent one end of the body for engagement with a rotational fastener or a fastener-engageable accessory, drive means rotatably mounted adjacent the other end of the body, and transmission means between the drive means and the engagement means, so that rotation of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A tool for rotationally secured fasteners This invention relates to a tool for rotationally secured fasteners, such as screw fasteners. It is often necessary to secure or release such fasteners in positions which render rotation of a tool engaged with the fastener difficult. This may be due to poor visibility, problems of access for a hand or arm, or due to obstructions limiting rotational movement of the tool to a small arc. The present invention provides a tool which reduces this problem. In accordance with this invention, there is provided a tool comprising an elongate body, engagement means rotatably mounted adjacent one end of the body for engagement with a rotational fastener or a fastener-engageable accessory, drive means rotatably mounted adjacent the other end of the body, and transmission means between the drive means and the engagement means, so that rotation of the drive means can effect rotation of the engagement means. The engagement means may comprise a socket for engaging a tool head such as a spanner head or screwdriver head, or the engagement means may be defined by a tool head. The drive means may mount a handle, or be adapted to mount a handle to facilitate rotation thereof. The transmission means may comprise gearing, but it is preferred that transmission is provided by a continuous band between the drive means and the engagement means in positive driven and driving connections therewith. In the preferred embodiment, a pawl and ratchet arrangement is provided in association with the engagement means to permit alternative use of the tool as a ratchet lever. Reference is now made to the accompanying drawings, wherein the sole Figure is an exploded perspective view of a tool according to the invention. The tool may bs used as a ratchet lever and the appropriate parts for this purpose are described first. The tool comprises an elongate hollow body of shallow depth comprising upper and lower body shells 12, 13. Each shell is adjustable in length and comprises two slidably interengaged parts 1 2a, 1 2b and 1 3a, 1 3b, one part of each shell having a iongitudinal slot 1 2c, 1 3c which aligns with an aperture 1 2d, 1 3d in the other part of the shell. By this arrangement fastening means engaged in the apertures 1 2d, 1 3d can secure the parts of each shell in different relatively adjusted positions. Each shell is formed adjacent each end with a circular-section dished part, defining a bearing 14a, 15a and 14b, 14c.Thetwo shells can be secured together, by fasteners engaged in apertures 16, so that each bearing 1 4a, 1 spa of one shell is axially aligned with a corresponding bearing 14b, 1 56 of the other shell. One set of bearings 1 Sa, 1 Sb, rotatably mounts a spigot 20, which circumferentially carries a sprocket 21. An axially projecting formation 22 is also carried by the spigot 20 and has the external form to mount a socket spanner head, e.g. the square-section shown. The formation also has a socket 23 for receiving a bit as an alterantive to the spanner head. The formation projects through a hole in one of the bearings 1 5a. The spigot 20 can be locked against rotation, in a manner to be described and this allows the body 12, 13 to be used as a lever for use in turning a socket spanner head. The other set of bearings 1 4a, 1 4b rotatably mounts a second spigot 25, which circumferentially carries a second sprocket 26. The spigot has a non-circular section axial aperture 27 therethrough for receiving a drive handle (not shown). The aperture 27 is accessible by the handle through holes in both of the bearings 14a, 14b. A transmission means in the form of a continuous chain 28 engages with the two sprockets 21, 26, so that rotation of the second spigot 27 causes rotation of the first spigot 20 and hence of a bit or spanner head carried by the formation 23. This permits operation from a remote location, so that obstacles to use of conventional tools can be avoided. A pawl 30 is rotatably mounted on the fastening means 31, which secures the shells together. The pawl can engage with either of two opposite runs of the chain 28 in a ratchet-like manner. When engaged with one run, rotation is prevented in one direction and vice versa; e.g. as illustrated, the chain 28 is prevented from movement in a clockwise direction, but can move in an anticlockwise direction. The pawl can be held in either selected engagement position and also in a neutral position. The pawl is rotatably mounted on a pin 31 and a resilient selector member 33 is mounted on the pin externally of the casing. The member has ramp surfaces 34 which can engage with walls of an indentation 35. The resilience of the member permits jamming of the ramp surfaces 34 against the walls of the depression to hold the pawl in either operative position. The pawl may, alternatively, engage with the sprocket 21 instead of the chain 28 and springbiasing means may be used for the pawl. The body length is adjustable, as described above, to permit adjustment of the tension on the chain. Claims

1. A tool comprising an elongate body, engagement means rotatably mounted adjacent one end of the body for engagement with a rotational fastener or a fastener-engageable accessory, drive means rotatably mounted adjacent the other end of the body, and transmission means between the drive means and the engagement means, so that rotation of the drive means can effect rotation of the engagement means.

2. A tool according to Claim 1, including a pawl and ratchet arrangement in association with the engagement means to prevent rotation in one direction.

3. A tool according to Claim 2, in which the pawl and ratchet arrangement is adjustable to prevent rotation of the engagement means in either selected direction.

4. A tool according to claim 1, 2 or 3, wherein the transmission means is a continuous band between the drive means and the engagement means and in positive engagement therewith.

5. A tool according to Claim 4, wherein the engagement means and the drive means carry sprockets and the transmission means is a chain engaged with the sprockets.

6. A tool according to Claim 4 or 5, as appendant to Claim 2 or 3, wherein the pawl engages with the continuous band.

7. A tool according to claim 6 including resiiient means biasing the pawl into engagement with either of selected opposite runs of the band.

8. A tool constructed substantially as herein described with reference to the accompanying drawings.