Scaffolding platforms

Abstract

A scaffolding platform 10 in which two pairs of legs 11, 12 are pivotally attached to the platform for folding between an operative and folded position beneath the platform, a first leg 11a of each p

Description

This invention relates to scaffolding platforms and in particular to such platforms in which pairs of legs are pivotally attached to the platform for folding between an operative position in which the platform is supported on the legs above a floor and a folded position in which the legs are folded beneath the platform for storage or transportation. Whilst such platforms exist, they tend to have support stays which hold the legs in their operative positions and which are somewhat awkward and time consuming to operate. There is therefore a requirement to provide such a folding leg arrangement which is quick and simple to operate and which ensures that the legs cannot be left accidentally in a state where they might collapse if a user were to attempt to stand on the platform. Thus according to the present invention there is provided a scaffolding platform in which pairs of legs are pivotally attached to the platform for folding between an operative position and a folded position beneath the platform, a first leg of each pair of legs being pivotally attached to the platform by a first push button pivot assembly having one or more plungers which are displaceable generally parallel to the pivot axis of the pair of legs by depressing a push button of the first push button pivot assembly to disengage the plungers from cooperating apertures carried by the platform and the first leg to allow pivoting of the pair of legs relative to the platform, the first push button pivot assembly being arranged to hold the plungers disengaged from the apertures when its push button has been depressed once whilst the first leg is at first and second predetermined angles relative to the platform corresponding to the folded and operative positions of the first leg, and a second push button pivot assembly for pivotally mounting a second leg of the pair of legs to the platform, the second push button pivot assembly having the same construction as the first push button pivot assembly, but being rotated through 180 degrees about a vertical axis before being connected with the platform and the second leg of the pair of legs, the second leg of the pair of legs being connected to the second push button pivot assembly so that the folded position of the pair of legs beneath the platform still corresponds with the first predetermined angle of the second push button pivot assembly but the operative position of the pair of legs no longer corresponds to the second predetermined angle of the second push button pivot assembly thus requiring the user of the scaffolding platform to continue to depress the push button of the second push button pivot assembly in order to retain its plungers disengaged from the cooperating apertures to allow movement of the pair of legs away from the operative position thus preventing accidental folding of the pair of platform legs. Not only does the above arrangement provide a fail-safe construction but it also gives an economic advantage in enabling the same push button pivot assembly to be used on both left and right hand sides of each pair of legs. The first and second push button pivot assemblies may have more than one predetermined angle corresponding to each of the folded and / or operative positions of the pairs of legs to provide more than one folded and / or operative position for the pairs of legs. One or more of the legs may be telescopic. One or more push button assemblies connect to the platform via corner brackets which also support a guard rail structure for the platform. One or more push button assemblies connect to the legs via inserts inserted into the ends of the legs. The present invention will now be described, by way of example only, with reference to the accompanying drawings in which :- Fig. 1 shows a perspective view of a scaffolding platform in accordance with the present invention in its operative position supported above the floor on two pairs of legs; Fig. 2 shows one end of the platform of Fig. 1 with its legs in their folded position beneath the platform; Fig. 3 shows part of the attachment of the legs of Fig. 1 in more detail; Fig. 4 shows an exploded view of one of the push button pivot assemblies which mount the legs onto the platform; Fig. 5 shows a side view of the first or left hand push button pivot assembly with the legs at a first predetermined angle corresponding to their folded position; Fig. 6 shows a side view of the first or left hand push button pivot assembly with the legs at a second predetermined angle corresponding to their operative position; Fig. 7 shows a side view of the second or right hand push button pivot assembly with the legs at a first predetermined angle corresponding to their folded position, and Fig. 8 shows a side view of the second or right hand push button pivot assembly indicating that the legs cannot move to the second predetermined angle so that the plungers will no longer be held disengaged from their apertures when their push button has been pressed once if the legs are in their operative position shown in dotted detail in Fig. 8. Referring to the drawings, a scaffolding platform 10 is mounted on two pairs of legs 11 and 12 which pivot on platform 10 about axes X via first and second push button pivot assemblies 13,13' mounted on corner brackets 14,14' secured to the platform. Each pair of legs includes steps 15 which assist the user in mounting onto the platform and legs 11 and 12 may be telescopic to provide several different heights for the platform 10 above the floor. Mounted on the platform via corner brackets 14,14' is a guardrail structure (not shown) which prevents the user from falling off the platform. One suitable form of guardrail structure is shown in, for example, UK patent GB2437737. As best seen in Figs. 3 and 4, first push button pivot assembly 13 has a first push button 18 on one end of a shaft 19 which extends through a cylindrical body 20 and which carries cross member 21 on its other end on which are mounted plungers 22 which slide within apertures 23a and 23b in bracket 14 when button 18 is pressed. When assembled, a protrusion 24 on cylindrical body 20 engages a slot 25 in an opening 26 in an insert 30 inserted into the end of the first or left -hand leg 11a so that when first leg 11a rotates about axis X the cylindrical body 20 is also rotated so that the push button assembly knows the angular position of leg 11a about axis X. Push button 18, plungers 22 and cross member 21 do not rotate about axis X but can move translationally along axis X. Plungers 22 engage with holes 23a,23b in bracket 14 and holes 27 in the insert 30 in the end of first leg 11a when the leg 11a is stowed under the platform and with holes 23a, 23b in bracket 14 and holes 28 in the insert 30 in leg 11a when the first leg is in its operative position. The internal details of the push button assemblies 13,13' (which do not form part of the present invention) are designed to recognise predetermined angles of the legs 11a, lib relative to their associated brackets 14,14' and to hold their buttons 18,18' in the depressed / disengaged position once the user presses the associated button once, and until the associated leg is rotated away from that predetermined position. Such push button assemblies are available from, for example, FUJIAN XIANGXIN LIGHT ALLOY MANUFACTURING CO. LTD. at https: / / www.xxaluminum.com / MT-22-Telescoping-ladders-22-Feet-Aluminum-pd43730100.html. In the present invention the stowed position under the platform is set up as a first predetermined angle or zero-angle position of the first assembly 13 in which plungers 22 engage with holes 27. The operative position is set up as a second predetermined angle or a 105-degree position which is located 105 degrees anticlockwise from the zero-angle position and in which plungers 22 engage with holes 28. Referring to Fig. 5 this shows the first or left leg 11a in its stowed position, the leg is horizontal and in the first predetermined zero-degree position of the push button assembly 13. Button 18 can then be pressed along axis X to disengage plungers 22 from holes 23a and 27 as far as holes 23b. When in this first predetermined zero-angle position the push button assembly remembers to hold button 18 in the depressed / disengaged position. Then the leg 11a can be rotated anticlockwise through 105 degrees until the second predetermined angle of the assembly is reached which corresponds to the operative position of the leg 11a (see Fig. 6) when holes 28 align with holes 23a and 23b. At that point plungers 22 spring back along axis X to engage with holes 28 and re-engage with holes 23a. To move the first leg 11a from its operative (105 degrees) position back to the (zero degree) stowed position button 18 is pressed once along axis X which disengages plungers 22 from holes 23a and 28 as far as holes 23b. When the button 18 is depressed in the operative position (105-degree angle) the push button assembly remembers to hold the button in the depressed / disengaged position. Then the leg 11a can be rotated clockwise by 105 degrees until holes 27 re-align with holes 23a and 23b. At that point plungers 22 spring back along axis X to engage with holes 27 and re-engage with holes 23a thus holding the leg 11a in its stowed position. In accordance with the present invention a second push button assembly 13' identical to first assembly 13 is installed between the bracket 14' and the insert 30' inserted into the end of the second or right-hand leg lib. This push button assembly 13' is rotated through 180 degrees about a vertical axis before being connected with the bracket 14' and the second leg lib (see Figs 7 and 8). Thus the leg lib extends to the right in Fig. 7 when in the stowed position as opposed to the leg 11a which extends to the left in Fig. 5. The first and second predetermined angles of the second assembly 13' are still 0 degrees (horizontal stowed position) and 105 degrees anticlockwise from the stowed position. These are the two angular positions at which the second assembly 13' will hold its plungers 22' (identical to plungers 22 of first assembly 13) disengaged from their various cooperating holes 27', 28', 23a' which are identical to the previously described holes 27, 28 and 23a of first assembly 13. Whilst the first predetermined angle (0 degrees) still coincides with the stowed position of the second leg arm lib (see Fig.7) the second predetermined angle, at 105 degrees anticlockwise from the stowed position, no longer coincides with the operative position of second leg lib (shown at the dotted position lib' in Figure 8) which would be past the vertical of the corner bracket 14' in position llb"and is thus not an achievable rotational position. Thus only the first predetermined angle is recognised by the second assembly 13'. Thus when the second leg lib is horizontal (zero-degree position) the button 18' of the second assembly 13' can be pressed along axis X to disengage its plungers 22' from holes 23a' and TT as far as holes 23b'. At this zero-degree angle the second push button assembly 13' is in one of the positions where the assembly remembers to hold the button 18' in the depressed / disengaged position. From here, the leg lib can then be rotated clockwise by 105 degrees until holes 28' align with holes 23a' and 23b'. At that point plungers 22' spring back along axis X to engage with holes 28' of the insert 30' and re-engage with holes 23a' to lock the leg lib in its operative position. However, this is not one of the predetermined positions where the hinge remembers to hold the button 18' and plungers 22' in the depressed / disengaged position once the user has pressed it. In order for plungers 22' to be disengaged, and stay disengaged, from holes 23a' and 28', the user must therefore press and continue to press / hold second button 18' so that the leg lib can be rotated back to the horizontal, stowed position. If the user does not continue to press and hold second button 18', plungers 22' will re-engage with holes 23a' and 28'. In the above description the operation of pivot assemblies 13,13' have been separately described regarding their effect on the legs 11a and lib for simplicity but the first and second legs 11a, lib are interconnected via steps 15 thus to move the legs 11a and lib from the operative to the stowed position both push button assemblies 13 and 13' need to be operated simultaneously. The first push button 18 only needs to be pushed once, whilst the second button 18'needs to be pressed and held pressed for the leg assembly to be released. Thus, the pair of legs 11a, lib are fail-safe and cannot be used unsafely, as at least one push button assembly of each pair of legs is locked, even if the scaffolding platform is accidentally left unattended. The other pair of legs 12 is attached to the platform 10 by the same push button assemblies 13,13' as used to mount the legs 11 described above. Thus the pairs of legs at both ends of the platform have the above described fail-safe locking arrangement. In the platform described above the first and second push button pivot assemblies may have more than one predetermined angle corresponding to each of the folded and / or operative positions of the pairs of legs to provide more than one folded and / or operative position for the pairs of legs.

Claims

1) A scaffolding platform in which pairs of legs are pivotally attached to the platform for folding between an operative position and a folded position beneath the platform, a first leg of each pair of legs being pivotally attached to the platform by a first push button pivot assembly having one or more plungers which are displaceable generally parallel to the pivot axis of the pair of legs by depressing a push button of the first push button pivot assembly to disengage the plungers from cooperating apertures carried by the platform and the first leg to allow pivoting of the pair of legs relative to the platform, the first push button pivot assembly-being arranged to hold the plungers disengaged from the apertures when its push button has been depressed once whilst the first leg is at first and second predetermined angles relative to the platform corresponding to the folded and operative positions of the first leg, and a second push button pivot assembly for pivotally mounting a second leg of the pair of legs to the platform, the second push button pivot assembly having the same construction as the first push button assembly, but being rotated through 180 degrees about a vertical axis before being connected with the platform and the second leg of the pair of legs, the second leg of the pair of legs being connected to the second push button pivot assembly so that the folded position of the pair of legs beneath the platform still corresponds with the first predetermined angle of the second push button pivot assembly but the operative position of the pair of legs no longer corresponds to the second predetermined angle of the second push button pivot assembly thus requiring the user of the scaffolding platform to continue to depress the pushbutton of the second push button pivot assembly in order to retain its plungers disengaged from the cooperating apertures to allow movement of the pair of legs away from the operative position thus preventing accidental folding of the pair of platform legs.2) A scaffolding platform according to claim 1 in which the first and second push button pivot assemblies have more than one predetermined angle corresponding to each of the folded and / or operative positions of the pairs of legs to provide more than one folded and / or operative position for the pairs of legs.3) A scaffolding platform according to claims 1 or 2 in which one or more legs are telescopic.4) A scaffolding platform according to any one of claims 1 to 3 in which one or more push button assemblies connect to the platform via corner brackets which also support a guard rail structure for the platform.5) A scaffolding structure according to any one of claims 1 to 5 in which one or more push button assemblies connect to the legs via inserts inserted into the ends of the legs.

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