GB2470952A

GB2470952A - Scaffold coupler

Info

Publication number: GB2470952A
Application number: GB0910136A
Authority: GB
Inventors: Wayne Mccrory
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-06-12
Filing date: 2009-06-12
Publication date: 2010-12-15
Also published as: GB0910136D0

Abstract

A scaffold coupler comprises a main body 4 and at least one clamp member 6 attached to the main body and movable from an open position to a closed position adapted to surround a scaffold member 14. The coupler also includes a threaded bolt 18 which is can be aligned with the clamp member in its closed position. The coupler also comprises a safety nut 26 with an inner thread corresponding to the threaded bolt and an outer circumferential surface which features indentations and /or projections. Preferably the outer circumference does not include any flat surfaces. The safety nut can only be loosened by use of a complementary shaped device, and so prevents unauthorised loosening of the nut when using a regular spanner or a hammer.

Description

I

Scaffold Coupler The present invention relates to a scaffold coupler, particularly but not exclusively to secure two scaffold members together, generally in a transverse arrangement.

Scaffold couplers are well known in the art and generally comprise a main body having two swivel clamps independently pivoted therefrom, which swivel clamps can be located around two usually transverse scaffold members, generally being longitudinal piping. The free ends of the swivel clamps are tightened against the main body by nuts on threaded bolts extending from the main body, and tightened by a spanner or other conventional fastening tool used by scaffolders to secure the fittings. A particular example of such scaffold couplers are generally known as right-angled couplers.

However, despite increasing health and safety legislation, there are still regular occurrences of scaffold couplers being loosened and even removed by non-scaffolders, generally being unauthorised persons', for example builders and painters, when their position or presence is deemed to be in the way of other requirements. As conventional scaffold couplers are tightened by use of ordinary nuts, usually hexagonal nuts on the threaded bolts, anyone with the correct spanner, or even by using sufficient force from a hammer, can loosen such nuts for their own purposes. Thus, it is still a relatively regular occurrence for scaffolding to collapse following to the loosening of one or more conventional scaffold couplers in this way.

It is an object of the present invention to provide an improved safety scaffold coupler.

Thus, according to one aspect of the present invention, there is provided a scaffold coupler comprising: a main body, at least one clamp member attached to the main body and movable from an open position to a closed position adapted to surround a scaffold member; a threaded bolt alignable with the clamp member in its closed position; and a safety nut having an inner thread corresponding to the threaded bolt and having an irregular outer circumferential surface.

By having an irregular outer circumferential surface, the safety nut can only be loosened by use of a complementary shaped device, avoiding or minimising the possibility of loosening of such a nut by a regular spanner or a hammer by unauthorised persons.

The scaffold coupler preferably has two or more clamp members, more preferably two clamp members. Such two clamp members are preferably in a transverse or right-angled arrangement so as to secure transverse or right-angled or perpendicular scaffold members, although the invention is not limited thereto, and can include scaffold couplers having at least two clamp members moveable in relation to each other in one or more dimensions.

The or each clamp member may be attached to the main body by any suitable arrangement, including one or more hinges, pins, pivots or other arrangements, generally allowing movements about one or more axis.

Preferably, the or each clamp member is attached to the main body through a pivot so as to be rotatable about the main body between its open position and its closed position.

In the open position of the clamp member, a scaffold member, generally being an elongate cylindrical tube or pole, can be located between the main body and the clamp member. Generally, it is the scaffold coupler which is located around a first scaffold member, following which the clamp member is moved to its closed position so as to wholly or substantially surround the scaffold member between it and the main body.

The scaffold coupler includes one or more threaded bolts corresponding to the number of clamp members. The threaded bolts are preferably connected to the main body through any suitable attachment, usually such that the threaded bolt is moveable between a free position and a secured position aligned with the clamp member in its closed position. One form of attachment is a pivotable arrangement such that the threaded bolt is rotatably moveable in relation to the main body.

Following alignment of a threaded bolt with a clamp member in its closed position, a safety nut is moveable along the threaded bolt to secure the clamp member against the main body, and therefore to secure the scaffold member in a fixed position in relation to the scaffold coupler, more usually also in relation to one or more other scaffold members fixed to the scaffold coupler.

The safety nut has an irregular circumferential outer surface. That is, the safety nut does not include on its outer surface at least two parallel flat surfaces associated with regular spanners, sockets, etc. having at least two complementary parallel flat surfaces. Thus, the unconventional or custom nature of the outer circumferential surface of the safety nut prevents its movement from a tight or tightened position by a conventional spanner, and requires a custom decoupler. For example, the safety nut could be pentagonal.

The custom decoupler required to tighten or untighten the safety nut has a complementary portion, usually a head portion, to the shape of the outer circumferential surface of the safety nut.

The outer circumferential surface of the safety nut may include one or more indentations and/or projections, such as slots, ribs or knuckles, optionally running transverse to the circumference of the safety nut.

In one embodiment of the present invention, the safety nut has a non-polygonal outer circumferential shape, including circular, eliptical, oval or a similar shape, and generally not including one or more flat surfaces.

In another embodiment of the present invention, the width of the safety nut is changeable along its depth. Thus, the outer surface of the safety nut may taper, generally from the side of the safety nut intended to abut the clasp member, to the non-abutting side.

In another embodiment of the present invention, the clasp member includes a housing able to at least partially surround the safety nut in its tightened position. Preferably, the clasp member is able to surround approximately half or more of the outer circumferential surface of the safety nut, to further hinder access to the outer circumferential surface of the safety nut in its tightened position by unauthorised persons.

An embodiment of the present invention will now be described by way of example only, and with reference to the accompanying drawings in which: Figure 1 is a side view of a scaffold coupler according to one embodiment of the present invention in a tightened position; and Figures 2a and 2b are top and side views of the safety nut shown in Figure 1.

Referring to the drawings, Figure 1 shows a scaffold coupler 2 comprising a main body 4 and two clamp members 6.

The main body 4 comprises a single-shaped piece having a first set of shoulders 8 able to house a first pivot or pin 10, and a second set of transverse shoulders 11 able to house a second pin 12.

Journalled on each pin 8, 12 are the clamp members 6, arranged to form a right-angled coupler so as to secure two scaffold members 14 in a transverse or perpendicular arrangement customary in the art. The invention is not limited to transverse or perpendicular arrangements, such that a scaffold coupler of the present invention may be able to secure two or more scaffold members in a different arrangement, and/or one or more scaffold members to one or more other items, apparatus, units or devices known in the art.

The main body 4 includes two bolt pin housings 16 (only one of which is shown in Figure 1) able to house a bolt pin 18, extending from which is a threaded bolt 20. In this way, the threaded bolts 20 are moveable relative to the main body 4, generally between a free position and a tightening position as shown in Figure 1 to be in alignment with the clamp member 6 as hereinafter described.

At the distal end of the clamp member 6, the clamp member 6 has a housing 22 with a slot 24, into which the threaded bolt 20 can be located, although the housing 22 may have any sort of passageway or throughhole into which the threaded bolt 20 can be located, and against which a safety nut can be fastened.

Figure 1 also shows two safety nuts 26, shown in more detail in Figures 2a and 2b. The safety nut 26 has a generally circular outer circumferential surface which tapers from a bottom surface 28, able to abut the housing 22 of the clasp means 6, towards a top surface 30. The safety nut 26 also includes a plurality of elongate slots 32 extending between the top and bottom surfaces 30, 28 of the safety nut 26.

In use, the scaffold coupler 2 is usually brought towards a first scaffold member 14 already in position, for the scaffold coupler 2 to be secured therearound to form a secure engagement between the scaffold member 14 and the scaffold coupler 2. A second scaffold member 14 can then be located between the main body 4 of the scaffold coupler 2 and the other clamp member 6 in its open position, following which the other clamp member 6 is moved to its closed position and the threaded bolt 20 is brought in alignment with the clamp member 6, particularly in alignment with the slot 24 in the housing 22 at the distal end of the clamp member 6.

The safety nut 26 may already be located on the threaded bolt 20 in a position which allows the alignment of the threaded bo't 20 with the housing 22, or may be separate therefrom. From a non-tightened position, the safety nut 26 is then tightened along the thread of the threaded bolt 20 in a manner known in the art so as to abut or engage a relevant surface of the housing 22. Further movement of the safety nut 26 tightens or fastens the clamp member 6 against the threaded bolt 20, and thus against the main body 4, and thus creates a tightened arrangement with the scaffold member 14.

In order to tighten or fasten the safety nut 26 along the threaded bolt 20, especially as increased pressure is required to rotate the safety nut 26, a custom tool is required having a complementary shape to that of the outer circumferential surface of the safety nut 26. With respect to the example of the safety nut 26 shown in the accompanying figures, the head of such a complementary tool would have a generally circular inner circumference, with a number of radial projections or knuckles to match the slots 32, and optionally also being tapered in a complementary fashion. The head of such a tool is sufficiently customised or unconventional so as to be not available to unauthorised persons. In addition, the outer circumferential surface of the safety nut 26 cannot be untightened or unfastened by conventional tools that an unauthorised person may typically have or have access to.

Figure 1 also shows the housing 22 having a countersunk portion 34, optionally formed by a raised outer wall 36, which countersunk portion 34 is able to at least partially surround the safety nut 26 in its tightened position as shown in Figure 1. Thus, not all of the outer circumferential surface of the safety nut 26 is accessible in a transverse direction, such that any complementary tool may require a socket-type head to fit in a vertically aligned arrangement with the safety nut 26, further hindering the possibility of an unauthorised person being able to unfasten or untighten the safety nut 26.

Thus, the present invention provides a safety coupler able to be used in conventional scaffolding, but having one or more safety nuts having an unconventional or irregular outer circumferential surface that prevents any or easily loosening of such couplers by unauthorised users.

Various modifications and variations to the described embodiments of the invention will be apparent to those skilled in the art without departing from the scope of the invention as defined herein. Although the invention has been described in connection with specific preferred embodiments it should be understood that the invention as defined herein should not be unduly limited to such specific embodiments.

Claims

Claims 1. A scaffold coupler comprising: a main body, at least one clamp member attached to the main body and movable from an open position to a closed position adapted to surround a scaffold member; a threaded bolt alignable with the clamp member in its closed position; and a safety nut having an inner thread corresponding to the threaded bolt and having an irregular outer circumferential surface.

Q
2. A scaffold coupler as claimed in Claim I wherein having two or more clamp members, preferably two clamp members.

Q
3. A scaffold coupler as claimed in Claim 2 wherein two such clamp members are in a transverse or right-angled arrangement.
4. A scaffold coupler as claimed in any one of the preceding claims wherein the or each clamp member is attached to the main body through a pivot so as to be rotatable about the main body between its open position and its closed position.
5. A scaffold coupler as claimed in any one of the preceding claims wherein the scaffold coupler includes one or more threaded bolts moveable between a free position and a secured position aligned with a corresponding clamp member in its closed position.
6. A scaffold coupler as claimed in claim 5 wherein one or more of the bolts are attached to the main body through a pivotable arrangement such that the threaded bolt is rotatably moveable in relation to the main body.
7. A scaffold coupler as claimed in any one of the preceding claims wherein the safety nut does not include on its outer surface at least two parallel flat surfaces.
8. A scaffold coupler as claimed in any one of the preceding claims wherein the outer circumferential surface of the safety nut includes one or more indentations and/or projections.

Q
9. A scaffold coupler as claimed in claim 8 wherein the one or more indentations and/or projections are slots, ribs or knuckles. (0 15
10. A scaffold coupler as claimed in claim 8 or claim 9 wherein the one or more indentations and/or projections run transverse to the circumference of the safety nut.
11. A scaffold coupler as claimed in any one of the preceding claims wherein the safety nut has a non-polygonal outer circumferential shape.
12. A scaffold coupler as claimed in claim 11 wherein the safety nut has a circular, eliptical, or oval outer circumferential shape.
13. A scaffold coupler as claimed in any one of the preceding claims wherein the safety nut has an outer circumferential shape not including one or more flat surfaces.
14. A scaffold coupler as claimed in any one of the preceding claims wherein the width of the safety nut is changeable along its depth.
15. A scaffold coupler as claimed in claim 14 wherein the outer surface of the safety nut tapers, preferably from the side of the safety nut intended to abut the clasp member, to the non-abutting side.
16. A scaffold coupler as claimed in any one of the preceding claims wherein the or each clasp member includes a housing able to at least partially surround the safety nut in its tightened position.
17. A scaffold coupler as claimed in claim 16 wherein the or each clasp Q member is able to surround approximately half or more of the outer circumferential surface of the safety nut. (0 15
18. A scaffold coupler substantially as herein defined and with reference to the accompanying drawings.