GB2444262A

GB2444262A - Scaffolding clamp

Info

Publication number: GB2444262A
Application number: GB0624043A
Authority: GB
Inventors: Lewis Alberto Grijo Dos Santos
Original assignee: ACCESS PRODUCTS Ltd; Product Solutions Catalysis Ltd
Current assignee: Product Solutions Catalysis Ltd
Priority date: 2006-11-30
Filing date: 2006-11-30
Publication date: 2008-06-04
Anticipated expiration: 2026-11-30
Also published as: GB2444262B; GB0624043D0

Abstract

A scaffolding locking device 14 for securing a scaffolding component 10 to a generally horizontally extending scaffolding tube 16. The locking device has a jaw portion 15 for partially encircling the tube 16 and a latch 19 mounted on the jaw portion adjacent the mouth 18 of the jaw portion. The latch 19 is biased to a closed position in which any tube within the jaw portion 15 is retained in the jaw portion and is displaceable away from the closed position by a tube 16 as the tube moves into the jaw portion. The latch also having a stable open position into which the latch must be moved by an operator to hold the latch open during disengagement of the jaw portion 15 from the tube 16. The latch means may stay in the stable open position until it is positively moved by the operator or the scaffolding component is angled away from the horizontal whereby gravity biases the latching means to the closed position.

Description

SCAFFOLDING

This invention relates to scaffolding and in particular to locking devices for securing a scaffolding component to a generally corresponding horizontally extending scaffolding tube. Such devices are used, for example, to secure a scaffolding platform to scaffolding tubes to hold the platform in position on the tube and prevent the platform being blown off the tube by high winds. Such locking devices can also be used to secure bracing tubes onto scaffolding frames etc. It is an object of the present invention to provide an improved form of the above scaffolding locking device which is both economical to manufacture, intrinsically safe, and easy to use.

Thus according with the present invention there is provided a scaffolding locking device for securing a scaffolding component to a generally horizontal extending scaffolding tube, the device comprising a jaw portion for partially encircling the tube and a latch means mounted on the jaw portion adjacent the mouth of the jaw portion, the latch means being biased to a closed position in which any tube within the jaw portion is retained in the jaw portion and being displaceable away from the closed position by a tube as the tube moves into the jaw portion, the latch means also having a stable open position into which the latch means must be moved by an operator to hold the latch means open during disengagement of the jaw portion from the tube.

In a preferred arrangement, the latch means remains in the stable open position until it is either positively moved therefrom by the operator or the scaffolding component is significantly angled away from the horizontal whereupon gravity biases the latching means to the closed position.

As will be appreciated, such a scaffolding locking device is not only of a simple and thus economical construction but also is easy to use since not only can the jaw portion be automatically engaged with the scaffolding tube but the release of the jaw portion is facilitated by the provision of the stable open position of the latching means which does not require the scaffolding assembler to maintain a continuous force on the latching means to hold it open during disengagement of the jaw portion from the tube. Also, the return of the latching means to the closed position under the action of gravity if the scaffolding component is angled away from the horizontal by more than say 15 degrees, makes the latching means in practice "self-priming" as almost inevitably the scaffolding component will be so angled as it is moved around between successive installations on scaffolding tubes.

In an alternative construction, the latch means is biased into the closed position by spring means which has a line of action which moves over-centre as the latch means moves between the open and closed positions.

The scaffolding locking device of the present invention is particularly suitable for use with a scaffolding platform to prevent the platform being blown off the tube in high winds. The present invention thus also provides a scaffolding platform provided with one or more locking devices in accordance with the present invention for securing the platform to a generally horizontally extending scaffold tube.

The invention also provides a scaffolding tube provided with a locking device in accordance with the invention at one or both ends of the tube for securing the tube to a generally horizontally extending scaffolding tube.

One embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:-Figure 1 shows a perspective view of one end of a scaffolding platform fitted with a locking device in accordance with the present invention for securing the platform to a horizontally extending scaffolding tube; Figure 2 shows a side view in the direction of arrow A of the locking device of figure 1; Figure 3 shows a side view in the direction of arrow B of the locking device of figure 1; Figure 4 is a perspective exploded view corresponding to figure 2; Figures 5 to 7 show a sequence of movement illustrating the insertion of a scaffolding tube into the locking device of figures 1 to 4; Figure 8 shows the locking device with the latching means held in an open position; Figures 9 and 10 show perspective views in opposite directions of the latching means used in the locking device of figures 1 to 4; Figure 11 shows a perspective view of a pivot pin used to mount the latching means offigures9and 10; Figure 12 shows a perspective view of a scaffolding platform with two locking devices in accordance with the present invention, one devices at each end of the platform at diagonally opposite corners, and Figure 13 shows a partly assembled scaffolding tower using two platforms of the form shown in figure 12.

Referring to the drawings, a scaffolding platform 10 has an outer rectangular aluminium frame 11 onto which boarding 12 is secured at 13. Secured to one corner of each end of the frame 11 is a locking device 14 in accordance with the present invention.

As best seen in figure 4, each locking device 14 has an aluminium jaw portion 15 designed to partially encircle a horizontal scaffolding tube 16 on which the platform is supported. The jaw portion is bolted to frame 11 at 17. The jaw portion 15 has a jaw mouth 18 through which the tube 16 is inserted. A latch 19 is pivoted adjacent mouth 18 on a pin 20 (see figure 11) which has a serrated portion 21 which is pressed or hammered into opening 22 in the jaw portion 15. The pin 20 has a smooth portion 20a on which latch 19 pivots and a shoulder 20b designed to contact the side of the jaw portion to control the depth D' of the smooth portion so that the latch can pivot freely. The other corner of each end of the frame 11 is provided with a jaw portion 15 which has no latch 19.

Figures 2 and 3 show the latch 19 in a closed position in which the tube 16 is retained in the jaw by the latch. The latch 19 has a weight concentration in portion I 9a which assists in biasing the latch to the closed position of figures 2 and 3 under the action of gravity as the centre of mass of the latch is to the right of pivot pin 20 (as viewed in figure 2) when the latch is in the closed condition which generates a turning force shown by the arrow X in figures 2 and 3 thus forcing tab 19d to engage an abutment I 5a on the associated jaw thus maintaining latch 19 substantially horizontal in the closed position.

Figures 5 to 7 show various stages in the installation of the jaw portion 15 on the tube 16. In figure 5 the jaw portion 15 is moved towards the tube 16 in the direction of the arrow Y with the latch 19 in the closed position. When the latch 19 contacts the tube 16 at corner 1 9b (see figure 6), and the movement of the jaw portion towards the tube 16 continues, the latch is rotated in the direction of the arrow Z to allow the tube 16 to pass through the mouth 18 of the jaw portion to the fully inserted position shown in figure 7 in which the latch 19 is clear of the tube 16 and is free to return under the action of gravity to the closed position of figures 2 and 3 in which the tube is held captive in the jaw portion.

In order to release the jaws from the tube 16 each latch 19 is pivoted in the direction of arrow R to its open position shown in figure 8 in which a flange I 9c on the latch

S

engages an abutment 11 a on the associated frame cross member 11. The latch is held in this open position, in which the jaw can be raised clear of the tube 16, by gravity as the centre of mass of the latch has moved "over-centre" to the left hand side of the latch pivot axis (as viewed in figure 8). Once the jaws have cleared the tube 16, the latches 19 can be again rotated to their closed position by the scaffolding assembler ready for the next engagement with a scaffolding tube. The latches 19 are also designed to be "self-priming" so that, if an end of the platform 10 is angled downwardly away from the horizontal by more than say 15 degrees, the weight concentrated in portion I 9a of each latch moves over-centre to automatically return the latch to its closed position ready for the next engagement with a scaffolding tube. Thus, almost inevitably, each latch will be automatically returned to its closed position as the platform is moved around between successive installations on scaffolding tubes.

Figure 12 shows a scaffolding platform 10 provided with jocking devices 14 one at each end of the platform to allow the platform to be secured to the top tubes 16 of two scaffolding tower frames 25 as shown in figure 13. These scaffolding tower frames could be of the form shown in the Applicant's co-pending UK patent application No. 0618106.9. The locking devices 14 are located at diagonally opposite corners of the platform. The other diagonally opposite corners simply have jaw portion 15 without the latches 19 as referred to above. If desired, four locking devices could be used on the platform, by providing each jaw portion 15 with a latch 19.

As will be appreciated, although the invention has been described above in relation to a latch 19 which is biased towards the closed position and held in the open position by gravity, this gravity bias could be augmented by,or replaced by, a spring whose line of action moves over-centre as the latch is moved between its open and closed positions.

Claims

1. A scaffolding locking device for securing a scaffolding component to a generally horizontally extending scaffolding tube, the device comprising a jaw portion for partially encircling the tube and a latch means mounted on the jaw portion adjacent the mouth of the jaw portion, the latch means being biased to a closed position in which any tube within the jaw portion is retained in the jaw portion and being displaceable away from the closed position by a tube as the tube moves into the jaw portion, the latch means also having a stable open position into which the latch means must be moved by an operator to hold the latch means open dunng disengagement of the jaw portion from the tube.

2. A locking device according to claim 1 in which the latch means pivots on the jaw portion between the closed and open positions.

3. A locking device according to claim I or 2 in which the latch means remains in the stable open position until it is either positively moved therefrom by the operator or the scaffolding component is significantly angled away from the horizontal whereupon gravity biases the latching means to the closed position.

4. A locking means according to claim 1 or 2 in which the latch means is biased into the closed position by spring means which has a line of action which moves over-centre as the latch means moves between the open and closed positions.

5. A locking device according to claim 3 or 4 in which first and second abutments on the latching means co-operate with complementary abutments on the jaw portion or scaffolding component to define the closed and open positions of the latching means.

6. A scaffolding platform provided with one or more locking devices according to any one of claims 1 to 5 for securing the platforrri to a generally horizontally extending scaffolding tube.

7. A scaffolding tube provided with a locking device according to any one of claims 1 to 5 at one or both ends thereof for securing the tube to a generally horizontally extending scaffolding tube.

8. A scaffolding device constructed and arranged substantially as hereinbefore described with reference to and as shown in the accompanying drawings.