GB2283795A - A tool for tightening a pipe clamp - Google Patents

Abstract

A tool for tightening a split clamping band 10 comprises an elongate handle 22 which is pivoted at its lower end to an abutment member 24 for abutting against an end of a threaded rod 12 at a point B where it is fixed to one end of the band 10. An elongate puller 26 is pivoted to the handle 22 and arranged to abut a bracket 14 on the other end of the clamping band 10. In use, the handle 22 is pivoted to draw the puller member 26 towards the abutment member 24. The nut 16 on the threaded rod 12 is then be tightened. <IMAGE>

Description

TIGHTENING TOOL This invention relates to a tool for use in tightening clamping bands around the flanged junctions between two duct members, particularly in heating and ventilating systems.

It has been proposed for lengths of duct to be joined end-to-end by engaging a ring-shaped clamping band over the flanged ends of the adjoining ducts, and then circumferentially tightening the clamping band. For example, our U.K. patent application No. 9305844.4 proposes a fan casing which comprises a duct formed of a sheet of metal wrapped into cylindrical form, and a ring-shaped flange attached to each end of the duct.

Hitherto, the clamping band has included a long, threaded rod fixed adjacent one end of the band and extending circumferentially and through a bracket fixed adjacent the other end of the band. A nut is engaged with the threaded rod to abut the end of the bracket, and is then turned to tighten the clamping band. However, the nut must be rotated through a large number of turns, and this process takes considerable time and effort, even when a powered rotary tool (or nut runner) is used. Furthermore, we have found that the opposite end of the bracket tends to bind against and tear or bite into the radially-inwardly facing side of the threaded rod.

We have now devised a tool for use in tightening clamping bands, which overcomes the above problems.

In accordance with this invention, there is provided a tool for tightening a split clamping band, the tool comprising an elongate handle which carries, at one end thereof, an abutment for abutting an end of a threaded rod where it is fixed to one end of the band, and a puller member pivoted to the handle and arranged to abut a bracket on the other end of the clamping band, such that by pivoting the handle the puller member is drawn towards said abutment.

Thus by a pivoting movement of the handle, the two ends of the clamping band are quickly drawn together. Then the nut on the threaded rod can be advanced quickly by finger to abut the bracket, before being finally tightened a few turns e.g. using a spanner.

Preferably the puller member is an elongate member having a transverse element at its free end, which is able to pass between the threaded rod and the clamping band and brought to abut the bracket of the clamping band, even whilst the nut is threaded on the rod.

Preferably the abutment member is pivoted to the handle, so that when the handle is turned in use of the tool, the abutment member remains stationary relative to the end of the band to which it is applied, and the handle is pivoted relative to the abutment member.

An embodiment of this invention will now be described by way of example only and with reference to the accompanying drawing, the single Figure of which shows the two overlapping ends of a clamping band and also, in longitudinal section, a tightening tool in accordance with this invention.

Referring to the drawing, there is shown a ringshaped clamping band 10 which is V-shaped in section, thus providing a radially-inwardly facing groove for engagement over two abutting flanges of two adjoining duct members (not shown). The clamping band 10 is split and its two ends can be moved towards each other to tighten the band around the abutting flanged ends of the two ducts. A threaded rod 12 is fixed adjacent one end of the band and extends circumferentially of the band and through a tubular passage of a bracket 14 fixed adjacent the other end of the band.

A nut 16 is engaged on the threaded rod 12 to abut the end of the bracket 14: hitherto, a powered rotary tool (or nut runner) has been used to move the nut along the threaded rod 12 and correspondingly move the two ends of the clamping band 10 towards each other. This procedure takes considerable time: also, we have found that the opposite end of the bracket 14 tends to bind against and bite into the radially-inwardly facing side of the rod 12, i.e. at the point indicated at P.

The drawing further shows a tool 20 which, by a pivoting movement, can draw the two ends of the clamping band together, after which the nut can be advanced along the threaded rod 12 by finger-turning, and then finally tightened using a spanner or other tool.

The tool 20 comprises a U-section metal handle 22 having a metal abutment member 24 pivoted to one end, and also a metal puller member 26 pivoted to it at a point spaced from the abutment member 24. The puller member 26 comprises a pair of parallel arms (one shown) the ends of which lie outside the opposite side elements of the Usection handle 22, and a pivot pin 27 extends through the two arms of the puller member 26 and the two opposite side elements of the handle 22. The puller member 26 further comprises a narrow strip 28 extending between the two opposite arms of the member, at its free end. The abutment member 24 comprises a U-section member positioned between the two opposite side elements of the handle 22 and pivoted thereto by a pivot pin 25. A rear end of the U-section abutment member 24 is closed by an inclined wall 29. The handle 22, abutment member 24 and puller member 26 are each formed of a one-piece member of sheet metal which has been cut to appropriate shape and then bent to the appropriate form.

In use of the tool 20, the strip 28 of the abutment member is slipped under the threaded rod 12 and nut 16, i.e.

between the rod 12 and the band 10, to abut the bracket 14 at point A. The abutment member 24 is positioned over the opposite end portion of the rod 12, for the edge of its wall 29 to abut the end of the rod at point B. Then the handle 22 is pulled in the direction of the arrow indicated, with the effect of drawing the end 28 of the puller member 26 towards the abutment member 24: thus the two ends of the clamping band are quickly and easily pulled together. The tool 20 is then removed, the nut 16 quickly spun by the fingers until it abuts the bracket 14, and the nut is then tightened a final few turns.

The tool thus enables the clamping band to be tightened in an easy and quick manner. Also, we have found that use of the tool avoids the bracket 14 binding against the threaded rod, as described above.

Claims (7)

Claims

1) A tool for tightening a split clamping band, the tool comprising an elongate handle which carries, at one end thereof, an abutment for abutting an end of a threaded rod where it is fixed to one end of the band, and a puller member pivoted to the handle and arranged to abut a bracket on the other end of the clamping band, such that by pivoting the handle the puller member is drawn towards said abutment.

2) A tool as claimed in claim 1, in which the puller member comprises an elongate member having a transverse element at its free end, which is able to pass between the threaded rod and the clamping band.

3) A tool as claimed in claim 2, in which the puller member comprises a pair of parallel arms inter-connected at their free ends by said transverse element.

4) A tool as claimed in any preceding claim, in which the puller member is pivoted to the handle at a point spaced from the abutment.

5) A tool as claimed in any preceding claim, in which the abutment comprises a member pivoted to the handle.

6) A tool as claimed in claim 5, in which the abutment member comprises a U-section member pivoted to one end of the handle.

7) A tool for tightening a split clamping band, the tool being substantially as herein described with reference to the accompanying drawing.