GB2427433A

GB2427433A - Climbing guardrail protection system for scaffolding towers

Info

Publication number: GB2427433A
Application number: GB0612037A
Authority: GB
Inventors: Andrew Charles Owens
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-06-21
Filing date: 2006-06-19
Publication date: 2006-12-27
Anticipated expiration: 2026-06-19
Also published as: GB0612037D0; GB0512597D0; GB2427433B

Abstract

The system comprises end frames 2 and telescopic fixed side rails 4 which form a protective guardrail for use whilst erecting and dismantling the scaffolding towers. Rotatable hooks 8 allow the end frames 2 to be raised vertically from within the scaffolding tower without the hooks impeding the raising process, but allowing the frames to be hooked onto a higher frame member automatically. The end frames 2 may also incorporate a pair of locking devices 16 which are pivotly connected to the frame side member by spindles (17 figure 3a) incorporating a body portion (18 figure 3a) which blocks the jaw of the hook thereby preventing the frame from being raised vertically. The locking device may be rotated to unblock the hook aperture when it is required to release the frame from the locked position.

Description

CLIMBING GUARDRAIL PROTECTION SYSTEM

FOR SCAFFOLDING TOWERS The present invention relates to scaffolding and more particularly to guard rails therefor. Scaffolding has long been used in industry for gaining access to high and awkward locations. Whilst scaffolding provides a safe environment for operatives to work this is not always the case for the persons erecting the scaffolding structures. Systems exist for providing temporary safety rails in advance of the erection of the scaffolding but are primarily designed for guarding the outside fence and ends of the scaffold and due to the complexity of the designs they are an expensive addition to the scaffolding project. This invention therefore relates to a system of safety rails for use on scaffolding towers whereby guardrail protection is provided in advance of a tower access platform being installed. The safety rails provided are independent of the scaffolding structure and are so arranged that the scaffolding towers can be erected and dismantled by operatives working within the perimeter of the safety rail system. Once in place on the scaffolding tower at a position safely accessible from ground level, the safety rail system may be progressively relocated upwardly to higher levels of the scaffolding tower by action taken from within the safety of the guardrail system of the scaffolding tower. During dismantling, the safety rail system may be progressively relocated downwardly to lower levels by actions taken within the scaffolding tower to provide a safe working environment for the operatives. When the scaffold tower is erected to the required height, it is not necessary to remove the advance guardrail system which may be left in place as a semi-permanent safety system until such time as dismantling of the scaffolding is performed. Additional safety rail end frames may be placed alongside the system and the adjacent handrails relocated to provide a double width platform. According to a first aspect of the present invention, there is provided a guard rail system for scaffolding, comprising first frame members and protection barrier means, two pairs of claw hook means mounted rotatably to each said first frame member such that when one said first frame member is moved to a new position by operation from a location within the scaffolding, the hook means may so rotate as to disengage with a horizontal transom member of the scaffolding and readily engage with an adjacent transom member. According to a second aspect of the present invention, there is provided a guard rail protection system incorporating end frames and side protection barriers with each end frame incorporating two pairs of rotatable multiple claw hooks arranged around a central aperture forming a pivot point whereby the hook members are free to rotate on spindles such that when the end frame is raised to a new position within the scaffolding the hooks rotate to avoid the horizontal transom members of the scaffolding but which having passed the obstructing members the hooks are presented in such a position as to be readily hooked onto the nearest available transom member. The guard rail protection system may include rotating hooks with a single hook jaw which may be incorporated with a counterbalance weight or a spring bias to return the hook to the desired engagement position. Preferably the guard rail protection system has end frames incorporate a pair of rotatable locking devices which block the jaws of one pair of hooks preventing the frame from being raised vertically or rotated laterally and which may be rotated to unblock the hook aperture when it is required to release the frame from the locked position for re-positioning. In this case, the device may be biased into the locked position by a counterweight formed within the locking device or by the action of a spring mechanism. The guardrail device may have telescopic side rails pivotally connected to releasable lugs on the end frame members. The guardrail device may have fixed side frame members may be rigidly connected to the end frame members. The invention will now be more particularly described by way of example and with reference to the accompanying drawings, in which:- Figure 1 shows a side elevation of the guardrail system incorporating fixed side barriers; Figure 2 shows a side elevation of the guardrail system incorporating telescopic side barriers pivotally connected to opposite end frames; Figure 3a to 3f show enlarged partial elevations of one of the rotating claw mechanisms demonstrating the sequential vertical movement and consequential rotation and engagement of the claw; Figure 4 shows a side elevation of a pair of the guardrail end frames together with telescopic handrails located onto the lower frame members of a scaffolding tower; Figure 5 shows a side elevation of the guardrail system being advanced up the rungs of the scaffolding tower frame members;Figure 6 shows a scaffolding platform being inserted within the side members such that the guardrails are already in place prior to platform erection; and Figure 7 shows further erection of the scaffold tower from within the guarded framework of the safety guardrail system. The system includes a pair of guard rail end frames (2) each comprising a pair of side members (4) connected together by horizontal spacing members (6) forming a rigid frame. Each pair of guardrail end frame members incorporates two pairs of multiple claw hooks (8) arranged around a central aperture forming a pivot point (10). The hook members typically having at least three hook portions (12) are pivotably connected through this pivot point to the side frame members such that they are free to rotate on spindles (14) passing through holes in the side members. The end frames (2) also incorporate a pair of locking devices (16) which are pivotably connected to the frame side member by spindles (17) incorporating a body portion (18) which blocks the jaw of the hook thereby preventing the frame from being raised vertically. The locking device may be rotated to unblock the hook aperture when it is required to release the frame from the locked position. Each frame may be biased in the locked position by a counterweight formed within the locking device or by the action of a spring mechanism. Rotatable hooks with a single hook may be incorporated with a counterbalance weight or a spring bias to return the hook to the desired operating position. The end frames incorporate fixing means to rigidly attach side guard members (20) to the end frame assembly. Alternatively the end frames may incorporate lugs (22) such that telescopic handrails (24) may be pivotally attached to these lugs. The operation of the hook mechanism is now described in detail with reference to Fig 3 a-f Figure 3a shows the rotatable hook (8) pivotally connected to the frame side member together with the locking device (16) which is also pivotally connected to the frame side member. Figure 3b shows the frame member being offered up to the scaffolding tower tubular rung member (30). Figure 3c shows the frame side member being raised causing the hook to rotate anticlockwise. Figure 3d and 3e show further raising of the frame member causing continued rotation of the hook member such that the hook jaw (32) closes over the frame tubular member at this point the locking device is retracted to allow the frame to be fully raised.Figure 3f shows the frame member being lowered to fully engage the jaw of the rotating hook around the tubular rung at which point the locking device is allowed to deploy into the locking position thus preventing further movement or removal of the guard rail frame. To use the guardrail system, the lower sections of a scaffold tower are erected at ground level as shown in Figure 4. A pair of end guardrail sections are attached at a convenient working height to each tower end frame such that they are opposite one another and then telescopic handrails or fixed guard side frames are attached to the guardrail end frames to form a continuous perimeter barrier. Whilst standing within the framework of the tower structure the safety frame may be released from the scaffolding frame and moved upwards causing the telescopic handrails to extend and causing the hooks to rotate until contact is made with the next frame rung, further movement causes all four hooks to rotate and engage around the frame members. The frame is then lowered slightly until the hooks lock around the frame members as shown in Figure 5. Similarly the opposite safety frame may be raised one or two pitches up the tower until the desired height is achieved. When both safety frames are at the required position the scaffold platform may be placed in position between the upper pair of rotating hooks to provide a safe guarded platform as shown in Figure 6. Access onto the scaffold platform is usually provided by a trapdoor within one end of the platform. Further tower components may be added to the tower structure from the safety of the guarded deck, (Figure 7), until the desired tower structure is complete.

Claims

1. A guard rail system for scaffolding, comprising first frame members and protection barrier means, two pairs of claw hook means mounted rotatably to each said first frame member such that when one said first frame member is moved to a new position by operation from a location within the scaffolding, the hook means may so rotate as to disengage with a horizontal transom member of the scaffolding and readily engage with an adjacent transom member.

2. A guard rail protection system as claimed in claim 1, wherein the hook members are free to rotate on spindle means.

3. A guard rail protection system as claimed in either claim 1 or claim 2, wherein the rotatable hook means comprise a single hook jaw with a counterbalance weight to return the hook to the desired engagement position.

4. A guard rail protection system as claimed in either claim 1 or claim 2, wherein the rotatable hook means comprise a single hook jaw with a spring bias to return the hook to the desired engagement position.

5. A guard rail protection system as claimed in any one of the preceding claims wherein each first frame member is provided with a pair of rotatable locking devices each of which in a first disposition blocks the jaws of one pair of hook means to prevent the frame from being raised vertically or rotated laterally and which may be rotated to a second disposition to unblock said jaws so as to release the frame member for repositioning.

6. A guard rail system as claimed in claim 5, wherein each locking device is biased into said first locking disposition by a counterweight within the locking device.

7. A guard rail system as claimed in claim 5, wherein each locking device is biased into said first locking disposition by a spring means.

8. A guard rail device as claimed in any one of the preceding claims wherein the protection barrier means comprise telescopic side rails pivotally connected to releasable lugs on the first frame members.

9. A guard rail device as claimed in any one of the preceding claims, wherein the protection barrier means comprise fixed side frame members rigidly connected to each first frame member.

10. A guard rail system for scaffolding substantially as described herein with reference to the Figures of the accompanying drawings.