GB2362921A

GB2362921A - Lockable scaffolding claw

Info

Publication number: GB2362921A
Application number: GB0113394A
Authority: GB
Inventors: John Francis Travers; Adam Rossi
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-06-02
Filing date: 2001-06-02
Publication date: 2001-12-05
Anticipated expiration: 2021-06-02
Also published as: GB2362921B; GB0113394D0

Abstract

A claw for use with scaffolding. The claw 1 is operative to capture another scaffolding component, for example a tube. The claw 1 includes a locking means 16,17 operative to prevent release of a captured component without the use of a key 18.

Description

f 2362921 ---1 15 SCAFFOLDING APPARATUS The present invention relates to

apparatus for use with scaffolding.

Scaffolding is generally constructed from a number of poles or tubes. In one known arrangement claws with releasable latches are fastened to the ends of the poles or tubes. The claws are arranged to capture a pole or tube. They enable one pole or tube to be quickly latched onto, and released from, another. This facilitates rapid assembly and disassembly of scaffolding but also leads to problems.

Scaffolding components are expensive. They are often made from aluminium and have a readily realisable scrap value. As such they are vulnerable to theft.

In some countries, such as the United Kingdom, regulations require that scaffolding be erected by a competent person. At present, however, once erected by a competent person there is nothing to stop an unauthorised non-competent person removing or rearranging scaffolding components and thereby potentially compromising safety.

Another problem, particularly with mass market products, is that where different parties on the same site are using a similar scaffolding system and components of each party's scaffolding are easily interchanged a conflict of ownership can arise.

The present invention has been made in consideration of these problems.

1 _. 1E According to a first aspect of the present invention there is provided a claw for use with scaffolding, the claw being operative to capture another scaffolding component and including a locking means operative to prevent release of a captured component without the use of a key.

As used herein "key" is to be understood to mean another separate component or information, such as a code, necessary to permit the locking means to allow the claw to release a captured component.

Keys may be issued to selected persons authorised to separate scaffolding components thus preventing unauthorised disassembly or rearrangement of scaffolding and reducing theft. Different parties may use claws requiring different keys, preventing one party from disassembling the other party's scaffolding and thereby reducing the risk of ownership conflicts.

The claw is preferably operative between a first position in which it may capture a scaffolding component ar-1.4 a second position in which it may release a captured component. The claw preferably includes a releasable latch means operative to retain it in the first position. The latch means may be manually operable. The locking means is preferably operable to prevent operation of the latch means.

In one embodiment the locking means preferably comprises a boot operative to restrict movement of the latch means. The boot is preferably mounted on a rotatable shaft. The rotatable shaft is preferably rotatable by means of a key. The key is preferably a separate component which is engageable with the shaft, and particularly with a barrel disposed in the shaft. The key is preferably only removable from the shaft when the lock is in either the first or second operative positions. In an alternative embodiment the locking means comprises a combination lock and the key is a combination for that lock. The boot is preferably movable between a first operative position where it restricts operation of the latch means and a second operative position where it does not restrict operation of the latch means.

In another embodiment the locking means comprises a barrel and plunger. The plunger is slidably mounted in the barrel and operable between locked and unlocked positions. The plunger is connected to a member operative to restrict movement of the latch means when the plunger is in the locked position.

The locking means may be arrang--1 so that the claw is automatically locked when used to capture another component. Alternatively, the locking means may allow the claw to be used in the conventional manner, that is without locking, if desired.

The claw is preferably adapted to capture a substantially cylindrical component, for example a pipe or tube. The claw preferably comprises a jaw, operable between an open and closed position.

According to. a second aspect of the present invention there is -1.5 provided apparatus for use with scaffolding comprising a manually releasable latch means operative to capture another scaffolding component and a locking means operative to prevent release of a captured component without the use of a key.

The latch means is preferably manually operable between a first position in which it may capture a sc.-.lfolding component and a second position in which it may release a captured component. The locking means is preferably operable to prevent operation of the latch means.

In one embodiment the locking means preferably comprises a boot operative to restrict movement of the latch means. The boot is preferably mounted on a rotatable. shaft. The rotatable shaft is preferably rotatable by means of a key. The key is preferably a separate component which is engageable with the shaft, and particularly with a barrel disposed in the shaft. The key is preferably only removable from the shaft when the lock is in either the first or second operative posit ions. In an alternative embodiment the locking means comprises a combination lock and the key is a combination for that lock. The boot is preferably movable between a first operative position where it restricts operation of the latch means and a second operative position where it does not restrict operation of the latch means.

The locking means may be arranged so that the latch means is automatically locked when used to capture another component. Alternatively, the locking means, may, t. 'low the latch means to be used without locking if desired.

The apparatus is preferably adapted to capture a substantially cylindrical component, for example a pipe or tube. The apparatus preferably comprises a jaw, operable between an open and closed position and may be a claw.

In order that the invention may be more clearly understood embodiments thereof will now be described by way of example with ---11 z reference to the accompanying drawings of which:

Figure 1 shows a part cut away view of an embodiment of a claw according to the invention in an open position; Figure 2 shows a view similar to Figure 1 but with the claw in the closed position; and Figure 3 shows a view similar to Figure 1 of another embodiment of a claw according to the invention in an open position.

Referring to Figures 1 and 2 a claw comprises a body 1 supporting a pivoting member 2 which together form a jaw for receiving and retaining a length of tubing, or similar.

The body 1 comprises an aluminium casting. One end forms an insert portion 3, adapted to be inserted into a length of aluminium scaffolding tubing 4 to which the claw may be welded. The opposite end of the body 1 to the insert portion 3 forms a hook 4 for receiving a tube 5 or similar.

The inside surface of the hook 4 is.-ierverally arcuate to enable it to cooperate with an object of circular cross-section.

The pivoting member 2 is pivotally connected to the body 1 by pivot 6 and comprises two arms 7 and 8, extending either side respectively of the pivot 6. Arm 7 extends around the inside of the hook 4 and arm 8 extends out of the hook 4. The pivoting member 2 is curved and has generally arcuate inner and outer surfaces, save for the tip of arm 8 which is generally flat sided and extends outside the radius of curvature of the -7remainder of the member 2. The inner surface has approximately the same radius of curvature as the inner surface of the hook 4. The outer surface includes an outwardly projecting lug 9, positioned slightly displaced along the arm 8 from pivot 6.

A latch member 10 is also pivotally connected to the first pivoting member 1, by pivot 11. The latch member 10 is elongate, fastened to the remainder of the claw near one end and hooked at its opposite end. The latch member 10 is also spring loaded by way of a spring 12 operative to urge the latch member 10 towards the pivoting member 2 so that the end of the hooked part of the latch member bears against the pivoting member The latch member 10 also includes a projection 13 extending from the side of the latch member 10 facing the pivoting member 2. The projection 13 on the latch member is disposed to cooperate with the projection 9 on 1 -5 the pivoting member 2 to enable +1h-,pivx-',n,g- member to be moved between two operative positions relative to the remainder of the claw, an open position in which a circular body, for example a tube, may be moved into and out of the jaw and a closed position in which the circular body may be retained by the jaw.

The open position is shown in Figure 1. In this position the projections 9,13 of the pivoting member 2 and the latch member 10 abut one another. The effect is to lock the two members relative to one another in a position where the inside surface of arm 7 of the second pivoting member is disposed within the radius of the inside surface of the hook 4.

The closed position is shown in Figure 2. The claw is arranged to automatically adopt the closed position when the hook 4 is urged over a pipe, or similar. When the hook 4 is urged over a pipe the pipe will exert a force on arm 7 of the second pivoting member, tending to urge the arm into a recess 14 formed in the inside surface 15 of the hook 4 and thereby to pivot the pivoting member 2 about pivot 6. This causes the abutting surfaces of the two projections 9 and 13 to slide, separating the projections. This unlocks the pivoting member 2 from the latch member 10 whereupon the latch member 10 urges the pivoting member 2 into the closed position. Movement of the pivoting member 2 under the action of the spring loaded latch member 10 is prevented by the outside of the arm 7 coming into contacting with the surface of the recess 14 in the hook 4.

-1 r In the closed position the sides of the projecting lugs 9 and 13 abut one another as compared with the open position, locking the pivoting member 2 into the closed position. In the closed position arm 8 of the second pivoting member prevents removal of a tube from the jaw.

To release the jaw the latch member 10 must be moved against the action of the spring 12, away from the pivoting member 2 to separate the two projections 9,13 and allow the pivoting member 2 to move back to the open position.

The claw further includes a locking means. This comprises-a boot 16, mounted on a rotatable shaft 17 which may be rotated by means of a separate removable key 18. The boot 16 extends radially away from the axis of rotation of the shaft 17 which is disposed so that by rotation of the shaft the boot 16 may be brought towards or away from the outside surface of the latch member 10. In particular, the boot 16 may be brought into contact with or sufficiently close to the surface of the latch member 10 when the claw is in the closed position to prevent movement sufficient to release the pivoting member 2 so that the open position may be adopted.

The boot 16, shaft 17 and key 18 are formed from metal, but could be formed from a plastics or any other suitable material. The boot 16 may be of any suitable shape. Essentially, though, it will be appreciated that it must form a non-symmetrical projection about the shaft 17.

When the claw is secured onto a tube, or the like, it may be locked in the closed position such that. it nnnno.-L -',e femoved from the tube without the use of the key. It is therefore possible to restrict who may remove a claw and hence separate scaffolding components, overcoming the problems associated with conventional scaffolding which cannot be locked.

The key may take any suitable form.

Referring now to figure 3 the illustrated embodiment is substantially the same as that shown in Figures 1 and 2 save that the latch member includes a further projection 19, and that the shaft 17 and boot 16 are replaced by a barrel 20, plunger 21 and rod 22 lock arrangement.

The projection 19 extends from the side of the latch member 10 facing away from the pivoting member 2 into a region beneath the lock arrangement 20,21,22. The projection 19 thus moves with the latch member 10 between the open and closed positions. The lock arrangement comprises a barrel 20 mounted on the body 1 of the claw. A plunger 21 is slidably mounted on the barrel 20 and may be moved between a locked position where it is depressed into the barrel 20 so that the top of the plunger 21 lies flush with the top of the barrel 20 and an unlocked position where it protrudes from the top of the barrel as shown in Figure 3. The barrel 20 and plunger 21 are arranged so that when the plunger 21 is moved to the locked position it can only be moved back to the unlocked position by inserting and turning an appropriate key 18.

The plunger 21 is connected to a rod 22, arranged such that when --157 the plunger 21 is in the locked, ps t ort. he rod prevents movement of the latch member 10 from the closed position to the open position, by contacting the projection 19. To move the latch member 10 to the open position it is necessary to move the plunger 21 to the unlocked position using the key 18.

The above embodiments are described by way of example only and many variations are possible without departing from the invention.

1 - -l r

Claims

1 A claw for use with scaffolding, the claw being operative to capture another scaffolding component and including a locking means operative to prevent release of a captured component without the use of a key. A claw as claimed in claim 1, operative between a first position in which it may capture a scaffolding component and a second position in which it may release a captured component. A claw as claimed in claim 2, including a releasable latch means operative to retain it in the first position. A claw as claimed in claim 3, wherein the latch means is manually operable. Apparatus for use with scaffolding comprising a manually releasable latch means operative to capture another scaffolding component and a locking means operp-+;,,,"- to. prevent release of a captured component without the use of a key.

6. Apparatus as claimed in claim 5, wherein the latch means is manually operable between a first position in which it may capture a scaffolding component and a second position in which it may release a captured component.

7. Apparatus as claimed in any of claims 3 to 6, wherein the locking means is operable to prevent operation of the latch means.

2.

3.

4.

5.

i 10.

l r_, 14.

8. Apparatus as claimed in claim 7, wherein the locking means comprises a boot operative to restrict movement of the latch means.

9. Apparatus as claimed in claim 8, wherein the boot is mounted on a rotatable shaft. Apparatus as claimed in claim 9, wherein the rotatable shaft is rotatable by way of a key.

11. Apparatus as claimed in claim 10, wherein the key is engageable with a barrel disposed in the rotatable shaft.

12. Apparatus as claimed in any of claims 1 to 7, wherein the locking means comprises a plunger slidably mounted in a barrel.

13. Apparatus as claimed in claim 12, wherein the plunger is operable between locked and unlocked positions and connected to a member operative to restrict movement of the latch means when the plunger is in the locked position.

Apparatus as claimed--- in ariv prreceding claim arranged to automatically lock when used to capture another scaffolding component.

15. Apparatus as claimed in any of claims 3 to 13, wherein the locking means may allow the latch means to be used without locking if desired.

16. Apparatus as claimed in any preceding claim adapted to capture a substantially cylindrical component.

17. Apparatus substantially as herein described with reference to Figures 1 and 2 of the accompanying drawings, or as modified as described with reference to Figure 3 of the accompanying drawings.