GB2211772A

GB2211772A - Torque box spanner

Info

Publication number: GB2211772A
Application number: GB8829681A
Authority: GB
Inventors: Charles Hugh Mcauley; May Mcauley
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-12-21
Filing date: 1988-12-20
Publication date: 1989-07-12
Anticipated expiration: 2008-12-20
Also published as: GB2211772B; GB8729687D0; GB8829681D0

Abstract

A torque box spanner comprises a tubular body 10 having at one end means 11, 32 for engaging a nut, bolt head or the like and at the other end a cap 16. A tool for location in the body 10 has a head 24 and a stem 22 with the stem 22 fashioned as a key 26 projecting out through an aperture 18 in the cap 16. The head 24 is biased by a helical spring 30 surrounding stem 22 against a pin 14 in the body 10 whereby the amount of torsion available to tighten a nut, bolt or the like is limited by the degree of compression of the biasing. The key 26 of the stem 22 is fashioned to fit the chuck of a brace or similar fitment of another rotating means. <IMAGE>

Description

SPANNERS.

This invention relates to a torque box spanner for use as a fitting or attachment for a joiner's brace or similiar rotating means for tightening or loosening nuts, bolts, or the like, and is particularly, but not exclusively, for tightening a nut or bolt to a required tension.

Accordingly, the present invention is a torque box spanner comprising a tubular body having at one end means for engaging a nut or bolt head or the like and at the other end a cap, and a tool for location in the body, the tool having a head and a stem with the stem projecting out through an aperture in the cap with the head being for biased abutment against a fixture in the body whereby the amount of torsion available to tighten a nut, bolt or the like is limited by the degree of compression of the biasing, the other end of the stem being fashioned to fit the chuck of a brace or similar fitment of another rotating means.

Preferably, the fixture in the body comprises a pin diametrically secured to opposite locations internally of the body. The head of the tool preferably has at least one diametrical groove across the side of the head remote from the stem and into which groove the pin is intended to seat. The head preferably has an annular wall extending in the direction away from the stem, the distal end of the wall having the or each groove therein.

Preferably further, the engaging means is a socket cap detachably secured to the body by friction fitment to a socket cap holder provided integral with the body.

The socket cap may have a female or male fitment engagable with a complementary male or female fitment on the body respectively.

Alternatively, the socket cap is screw-threadedly engaged with an internal or external screw-thread provided on the body.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawing, in which: Fig. 1 is a partially exploded side perspective view of a torque box spanner according to the present invention with part of the body cut-away for clarity to show the internal assembly; Fig. 2 is a side elevation of a body showing a scale externally thereof; and Fig. 3 is a perspective side and top elevation of a head of a tool for internal fitment in the body.

Referring to the drawing, a torque box spanner comprises a tubular, in this embodiment cylindrical, body 10 with one end having an integral male socket cap holder ii in the form of a peg, and the other end having an external screw thread 12. A detachable socket cap 32 having a complementary female fitment is provided for friction fit onto the male cap holder 11 at the one end.

Biased retaining means of conventional form is provided on the holder 11 to retain a cap 32 in position. The socket cap 32 may be one of a series of socket caps 32 for use with differently sized hexagonal or other shaped nuts or bolt heads or the like. A fixture is provided internally of the body 10 comprising a diametrical pin 14 secured internally to opposed locations in the tubular wall of the body 10.

A tool 20 is provided having a stem 22 with a head 24 at one end and with a rectangular key 26 being fashioned at the other end. The head 24 is dimensioned to fit internally of the body 10 and is provided with an annular wall 25, as shown in Fig. 3, extending in the direction away from the stem. Two diametrically arranged grooves 28 are provided in the distal end of said annular wall 25 as shown in Fig. 3. The two diametrical grooves 28 are provided off-set at 90 angular degrees to each other. The tool 20 is located head first into the body to abut against the pin 14 and is rotated till the pin 14 seats in one of the grooves 28 in the head 24. A helical spring 30, providing biasing, is located around the stem 22 for its inner end to abut the underside of the head 24. A spacer ring 34 is fitted into the body 10 as shown to abut the outer end of the spring 30.The spacer ring 34 extends a distance beyond the end of the body 10 as shown in Fig. 1.

A cap 16 having an aperture 18 co-axial in its top is provided with an internal screw-thread to engage the screw-threaded end 12 of the body 10. The cap 16 tightens against the spacer ring 34 and compresses the spring 30 as it is screwed onto the body 10, and when tightened provides a fixed seat serving to hold the head 24 against the pin 14 in its seat in one of the grooves 28 and against which spacer ring 34 the spring 30 is compressed when the head 24 moves theretowards when riding on the pin 14 as hereinafter described. The tightening of the cap 16 and therefore the compression of the spring 30 determines the tension to which nuts or bolts can be tightened by using the torque box spanner.

The left-hand side of each of the grooves 28 as seen in Figs. 1 and 3 is sloped as shown to allow the tool 20 to ride out of abutment with the pin 14 at the full extent of the selected torsion given to the spring 30. The cap 16 preferably has a hexagonal or square surround to allow for ready tightening of the cap 16 onto the body 10.

In use, with the torque box spanner assembled as above described, the key 26 can be fitted into a chuck of a joiner's brace or similar fitment of another rotatable means and be used to tighten or loosen nuts, bolts or the like. In tightening nuts, bolts or the like, when the nut, bolt or the like is tightened to the desired tension, the head 24 of the tool 20 as the spanner is further rotated will simply ride out of the groove 28 against the influence of the spring 30.

In a modification, the socket cap 32 is provided with a male fitment engagable with a female fitment provided on the body 10. Also, in the alternative, the socket cap 32 can be provided with a screw-thread internally or externally thereof to engage with a respective external or internal screw-thread provided on the body 10.

In a further modification, the fixture can be of any suitable construction, such as two diametrically opposed stub pins each extending inwardly a distance sufficient to engage in opposite ends of one of the grooves 28.

Variations and other modifications can be made without departing from the scope of the invention as above described.

Claims

CLAIMS:

1. A torque box spanner comprising a tubular body having at one end means for engaging a nut, bolt head or the like and at the other end a cap, and a tool for location in the body, the tool having a head and a stem with the stem projecting out through an aperture in the cap with the head being for biased abutment against a fixture in the body whereby the amount of torsion available to tighten a nut, bolt or the like is limited by the degree of compression of the biasing, the other end of the stem being fashioned to fit the chuck of a brace or similar fitment of another rotating means.

2. A box spanner as claimed in Claim 1, wherein the fixture in the body comprises a pin diametrically secured to opposite locations internally of the body.

3. A box spanner as claimed in Claims 1 or 2, wherein the head of the tool has at least one diametrical groove across the side of the head remote from the stem and into which groove the pin is intended to seat.

4. A box spanner as claimed in Claim 3, in which the head has an annular wall extending in the direction away from the stem in whose distal end the grooves are provided.

5. A box spanner as claimed in any one of the preceeding Claims, wherein the engaging means is a socket cap detachably secured to the body by friction fitment to a socket cap holder provided integral with the body.

6. A box spanner as claimed in Claim 5, wherein the socket cap has a female or male fitment engagable with a complementary male or female fitment on the body respectively.

7. A box spanner as claimed in Claim 5, wherein the socket cap is screw-threadedly engaged with an internal or external screw-thread provided on the body.

8. A torque box spanner substantially as hereinbefore described with reference to the accompanying drawings.