GB2161529A - A platform stand for a ladder - Google Patents

Abstract

A removable platform stand for a ladder has a platform with side supports (27,28) having recesses (31,32,33,34;) which, when the stand is fitted to a ladder, receive adjacent rungs (152, 153). The platform can be split and pivoted to allow a front part (35) to be folded back over a rear part (36) so that the platform does not obstruct the user when climbing or descending the ladder, and the stand may be provided with an adjustment mechanism by which the inclination of the platform with respect to the ladder can be adjusted to ensure that the platform is always horizontal whatever the inclination of the ladder. <IMAGE>

Description

SPECIFICATION A platform stand for a ladder The present invention relates to a platform stand for a ladder, and particularly to such a stand which is removably attachable to a ladder to provide an enlarged area for a user to stand on for extended periods without discomfort.

Although ladders are convenient and easy to use for gaining access to positions higher than otherwise would be accessible, they have the considerable disadvantage for use over an extended period of offering only a very narrow support surface for the feet of the user. If the job in hand requires a user to remain in the same position for some considerable time discomfort, and even pain, can be experienced due to the fact that only the balls of the feet are supported so that the pressure at these points is considerable. Further, the achilles tendons and calves are continually flexed in order to maintain balance. The human anatomy is adapted for the feet to rest on flat horizontal surfaces and the present invention seeks to provide such a surface on a ladder.

Clearly, each rung on a ladder cannot be made with an extensive wide surface since this would be inconvenient to store and difficult to use. The present invention seeks, therefore, to provide a single platform stand which can be attached to the rungs of the ladder in any convenient position along the length of the ladder to enable a user to stand on the platform for an extended period without experiencing discomfort.

The forward projection of the platform stand (and in this context the term "forward" will be understood to refer to projection in a direction towards the user and away from the vertical surface against which the ladder is supported) of the platform should preferably be minimised as far as possible or other arrangements are required to make it convenient for a user to pass the platform stand when climbing the ladder without inconvenience or risk of dislodgement from the ladder. However, it is also important that there be a reasonable projection on either side of a rung to allow for adequate balance and comfortable positioning of the feet. Of course, the platform stand must not have such a bulk that it is a serious obstacle to the user in descending the ladder.

According to one aspect of the present invention, therefore, a removable platform stand for a ladder, which can be positioned at one of a plurality of locations along the ladder to provide a support for a user, and having a greater area than a rung enabling the user to stand on the ladder for extended periods without discomfort, comprises a generally flat platform portion carried on supports having attachment means for attaching the stand to a rung of a ladder to transfer the weight of a user thereto, the said supports having a length greater than the spacing between two adjacent rungs of a ladder such that turning moments about the attachment rung are resisted by contact between the sides of the platform and the next lower rung of the ladder.

In a preferred embodiment of the invention the said attachment means comprise recesses in the edges of the said supports for receiving a rung of the ladder, the recesses being so shaped that the supports can be hooked over the rung for suspending the platform stand to the ladder. In order that the platform should be as closely aligned as possible with the vertical height of a rung, the said recesses preferably extend substantially to the junction between the said supports and the platform.

When climbing the ladder, therefore, the platform stand will offer a support at very approximately the same height as a rung rather than at a height in between two rungs so that the minimum disturbance to the regular spacing of the treads is occasioned thereby.

The said recesses are preferably downwardly open in position of use so that they may simply be hooked over the ladder rung to attach the platform stand to the ladder although in one embodiment the recesses have a cranked shape in order to allow the stand to be fitted with less risk of dislodgement.

The platform stand may incorporate a platform which is rigidly, and permanently, secured to the said supports and in a simple embodiment this is effected by making the said supports integral with the platform, folding the supports in the form of sides from a single blank of sheet metal.

The said side supports may each have two recesses for engagement by respective adjacent rungs of the ladder to provide an even more secure attachment of the platform to the ladder. This also enables the platform to extend rearwardly of the ladder, that is towards the vertical surface against which the ladder is supported, without there being any risk that the platform will be tilted if the weight of the user is placed on the platform at a horizontal location between the run and the vertical support surface against which the ladder is supported since turning moments in either directional sense about the attachment to either run will be resisted by the attachments to the other rung.

in another embodiment of the invention the platform is pivotally mounted on the side support to allow a user's foot to displace it from a rung to stand directly on the rung. In such an embodiment the platform may be formed in two parts hingedly mounted together with the hinge joining the two platform parts extending parallel to the pivot axis of the pivotal connection between the platform and the side supports.

A first of the two hingedly joined platform parts may be pivoted to the side supports and turntable in a first directional sense about the pivot between lowered working position and a raised position, and the second of the two hingedly joined platform parts may be hinged to the first part and turnable about the hinge axis in the opposite sense from the first in moving from the lowered, working position to the raised position.

The platform may be adapted to receive a board or plank to form a trestle with a suitable or similar support for the other end of the board or plank.

The platform may also be formed in two parts with a first or front portion being hingedly mounted to a second or rear portion which is rigidly secured to the side supports, the front portion being turnable between a working position in which it lies substantially coplanar with the rear portion and is supported on the side supports, and a raised position in which it overlies the rear portion to allow a user to climb past without obstructions.

The hinge line between the first and second portions may be substantially coincident with the vertical plane passing through the rung of a ladder to which the platform stand is attached. In this way when the first or forward portion of the platform is turned to its raised position overlying the fixed portion of the platform the tread formed thereby lies slightly higher than the associated rung but does not project forwardly therefrom so that in climbing the ladder the user experiences the minimum disturbance to the regular tread pattern. The said first portion may be resiliently biased towards the said lowered working position so that displacement between the working position and the raised position can be effected by the forward or leg of a user as he climbs past the platform, and once past, the platform will revert to the position of use.

As so far described the platform stand of the present invention has the disadvantage that the ladder must always be positioned at approximately the same inclination with respect to the vertical in order for the platform to be generally horizontal. If other constraints, such as obstacles or unsuitable ground, result in the ladder being unavoidably positioned at an inclination other than the optimum inclination, then the inclination of the platform is not horizontal and this could lead to inconvenience. Particularly if the ladder is inclined at a smaller angle to the vertical than the optimum inclination, then the platform will be inclined downwardly away from the wall and any tendency to slip will result in the feet of the user moving away from the ladder.An inclination of the ladder greater than the optimum angle will result in the platform being inclined inwardly towards the wall and although this is not in itself dangerous it could be uncomfortable and obviate the advantages gained from the platform itself.

According, therefore, to another aspect of the present invention, a removable platform stand for a ladder, positionable at one of a plurality of locations co-incident with the rungs along the ladder to provide a wider area of support for a user than the rungs of the ladder itself, and enabling the user to stand on the ladder for extended periods without discomfort, comprises a generally flat platform portion carried on side supports having attachment means for attaching the stand to a rung of a ladder, in which the attachment means of the side supports are adjustable whereby to vary the inclination of the plane of the platform with respect to the plane defined by the two stiles of the ladder.

The term "plane of the ladder" will hereinafter be understood to refer to the plane defined by the two faces of the stiles of the ladder facing away from a wall when a ladder is leant up against it.

The adjustment of the inclination of the plane of the platform with respect to the plane of the ladder may be incremental or discrete, or may be infinitely adjustable between two end positions. In either case, the attachment means may comprise two recesses or notches in each side plate for receiving rungs of the ladder when the platform is fitted thereto, one such recess in each side plate having an associated retaining member serving to retain the rung of the ladder at a selected position along its length to determine the inclination between the platform and the ladder. Preferably, the said one recess is arcuate having a centre of curvature which coincides with the intersection between the axis of a rung fitted in the other said recess or notch of the side plate and the plane of the side plate itself.

In a preferred embodiment of the invention the retaining member comprises a pivoted, bifurcated plate having arms spaced by a distance not less than the thickness of the rungs of a ladder on which the platform stand is anticipated to be used. In practice the thickness of rungs of a ladder vary only over a narrow range and this limitation therefore means that the arms of the bifurcated plate must be at least far enough apart to receive the thickest rung likely to be encountered in a commercially available ladder.

The adjustment of the inclination of the bifurcated plate with respect to the side of the ladder support may be achieved in any suitable way. For example, the bifurcated plate may have detente means for determining its angular position about the pivotal attachment to the associated side plate, in which case a plurality of discrete angular positions would be available to the plate. In such a case the detente means may comprise an arcuate array of openings in the side plate or in the retaining member, and a cooperating opening in either the retaining member or the side plate respectively, and a pin for insertion between aligned openings in the two said members at each selectable relative inclination between the retaining member and the side plate.Such a pin may be captive on one of the two members and resiliently urged into a position where it projects through an aligned opening in the other member.

Alternatively, the plate may be infinitely adjustable between end positions by means of an associated screw adjusting means the adjustment of which determines the relative inclination between the retaining member and the side plate.

Various embodiments of the present invents tion will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a first embodiment of the invention; Figure 2 is a side view of the embodiment of Fig. 1 showing it in partial section in position on a ladder; Figure 3 is a perspective view of an alternative embodiment of the invention; Figure 4 is a sectional side view of an alternative embodiment illustrating the platform in a position adopted immediately prior to being fitted on a ladder; Figure 5 is a sectional side view similar to Fig. 4 showing the side plate fitted in position on the ladder; and Figure 6 is a perspective view illustrating the embodiment of Figs. 1 and 2 in position on a ladder.

Referring first to Figs. 1 and 2, the platform stand is generally indicated with the reference numeral 11 and is adapted to be fitted to a ladder 1 2 having two parallel stiles 13, 1 4 spanned by identical regularly spaced rungs 1 5. In the drawings individual rungs have been identified with a subscript 1, 2, 3 etc., to the reference numeral 15, but these subscripts are for identification purposes only and it is not to be considered that the ladder stiles are numerically identified thereby.

The platform stand illustrated in Fig. 1 comprises a rigid rectangular platform 1 6 having depending rigidly connected side support walls 17, 1 8 integral with the platform 1 6 and formed by bending a substantial sheet metal blank which has been preliminarily cut to the required outline shape. Short reinforcing flanges 19, 20 folded down from the platform 1 6 and welded to the side supports 17, 1 8 are also provided for added security.

The side supports 17, 1 8 have aligned respective downwardly open notches or recesses 21, 22 shown in the drawings as being hooked over the rung 1 52. The lower edge of each side wall 17, 1 8 rests on the immediately lower rung 1 53 so that the platform 16 is able to support the weight of a user by transferring it to the rungs 1 52 1 53, and the platform 16 extends to both sides of the rung 152 with the rearward extension allowing the forward extension to be minimised so as to reduce the obstruction presented by the platform to the user climbing the ladder.Indeed, as will be appreciated from Fig. 2, when climbing the ladder the user must negotiate the front edge of the platform, defined by the flange 19, in order to be able to climb from the rungs 1 54, 1 53 to the higher rungs 1 52, 15" and this can be done either by bringing the feet sideways round the sides 17, 1 8 or by lifting them slightly higher than usual in order to clear the front edge 19.

The embodiment of Fig. 3 is adapted to minimise any inconvenience this may cause as will be described below.

Referring now to Fig. 3 the embodiment is broadly similar in comprising a platform generally indicated 26 supported on two side supports 27, 28 attachable to rungs 152, 1 53 of a ladder 12. In this embodiment, however, the sides 27, 28 are provided not only with downwardly open recesses 31, 32 for receiving the rung 1 53 of the ladder 12, but also additional recesses 33, 34 for receiving the rung 1 53. This dual interconnection of the two rungs with the side supports 27, 28 makes it entirely certain that the platform 26 cannot rock about the rung 1 53 if the weight of the user is placed on the rear portion of the platform 26.In the embodiment of Figs. 1 and 2, the platform could rock slightly in these circumstances and although the user's shin would contact rung 15, in order to prevent any substantially rocking motion from taking place this slight disadvantage is overcome in the embodiment of Fig. 3 by the provision of the two recesses. In order to allow for a variation in the rung spacing which may be experienced from one ladder to another if the stand is used on different ladders, the recesses 33, 34 are formed with a greater length than the minimum necessary to receive the rung 1 53 so that if the ladder spacing is greater the rung will still enter the recess, but may not be able to reach right to the end of the recess, being lodged partway along its length.

The most important difference between the embodiment of Fig. 3 and that of Figs. 1 and 2, lies in the fact that the platform 26 is split into two portions, a rear portion 36 and a forward portion 35 separated by a hinge line 37 parallel to the rungs of the ladder. A spring 38 resiliently biases the forward portion 35 of the platform 26 to the position illustrated in Fig. 3 which is the working position in which it is coplanar with the fixed portion 36. However, the forward portion 35 can be turned about the hinge line 37 against the action of the spring 38 to a position where it overlies the rear portion 36 as shown in broken outline in the drawings and identified by the reference numeral 35'.This dis placement can take place as the user climbs the ladder, by contact between the shin or foot of the user with the underface of the pivoted portion 35 allowing it to be displaced to the raised position illustrated in broken outline where it is only slightly higher than the rung 1 52 and does not project forwardly beyond the vertical plane passing through the rung. When the user's foot leaves the platform the portion 35 is urged back to the working position by the spring 38 so that the user may then place his foot on the platform and stand at any point over the whole area 26.

Although described as a pressed sheet metal construction it will be appreciated that any alternative construction employing and/or metal and/or plastics may be employed providing sufficient rigidity and strength is obtained thereby to support the weight of a user.

The platform stand may alternatively be used to support one end of a scaffold plank or board which may be suitably supported at the other end by a similar platform stand on a ladder to provide an extended area of use.

Referring now to Figs. 4 to 6 of the drawings, a ladder generally indicated 14 and having rungs indicated 15i, 153, 153 and 154 (see Fig. 3) is shown in an inclined position such as it would adopt when leant up against a wall (not shown). The ladder platform comprises a platform element 41 supported by two side plates 42, 43 having respective recesses 44, 45 therein. The recess 44 is a straight notch extending perpendicularly with respect to the platform 41 and open at an end remote from the platform 41 whilst it has a curved lined end towards the platform 41.

The recess 45, on the other hand, is arcuately curved and has a centre of curvature centred on the same point as the arcuately curved blind end of the recess 44. Thus, when the platform stand is fitted to the ladder the rung 1 52 enters the notch 44 and the rung 1 53 enters the notch 45 in such a way that the whole of the platform stand can turn about an axis defined by the central axis of the rung 1 52 coincident with the centre of arcuate blind end of the recess 44 throuugh a range of inclinations determined by the length of the arcuate slot 45.

In order to retain the platform stand in a selected position, a retaining member in the form of a pivoted bifurcated plate 46 is attached to each side plate 42, 43. The plate has two arms 47, 48 extending parallel to one another and spaced by a slot 49 having the same width as the arcuate slot 45 in the side plate 43. The plate 46 is pivoted at a pivot 50 and has two openings 51, 52 on a lug 53 which extends laterally from the main body of the plate 46. Two arcuate arrays 54, 55 of openings in the side support plate 43 of the platform are provided.These have a centre of curvature coincident with the pivot axis of the pivot 50 and a radius of curvature equal, respectively, to the distance between the pivot 50 and the openings 51 and the pivot 50 and the opening 52 so that the angular inclination of the bifurcated plate 46 with respect to the side plate 43 can be determined by inserting a pin through one of the holes 51, 52 and a selected one of the two rows of holes 54, 55 respectively.

Thus, as can be seen in Fig. 1, with the pin (not shown) removed the bifurcated plate is allowed to adopt a position where the arms 47, 48 extend almost vertically downwards from the pivot 50 so that a rung such as the rung 1 53 can be introduced into the space 49 between them and at the same time pass into the slot 45 whilst the adjacent higher rung 1 52 of the ladder is introduced into the recess 44. The inclination of the platform 41 is then adjusted in dependence on the inclination of the ladder 14 until the nearest available discrete position to the horizontal is achieved and then the pin is inserted through either the hole 51 or the hole 52 of the bifurcated plate 46 and whichever of the holes in the arrays 54, 55 is most nearly aligned therewith. This prevents further rotation of the bifurcated plate 46 which thus retains the rung 1 53 at the selected position along the length of the arcuate slot 45 as illustrated in Fig. 2 which shows the ladder 14 in approximately its position of greatest inclination with respect to the vertical.

Claims (23)

1. A removable platform stand for a ladder, which can be positioned at one of a plurality of locations along the ladder to provide a support for a user, and having a greater area than a rung enabling the user to stand on the ladder for extended periods without discomfort, comprising a generally flat platform portion carried on side supports having attachment means for attaching the stand to a rung of a ladder to transfer the weight of a user thereto, the said sides having a length greater than the spacing between two adjacent rungs of a ladder such that turning moments about the attachment rung are resisted by contact between the sides of the platform stand and the next lower rung of the ladder.

2. A removable platform stand as claimed in Claim 1, in which the attachment means comprise recesses in the edges of the side supports for receiving a rung of the ladder so shaped that the sides can be hooked over the rung for suspending the platform stand to the ladder.

3. A removable platform stand as claimed in Claim 2, in which the said recesses extend substantially to the junction between the side supports and the platform.

4. A removable platform stand as claimed in Claim 2 or Claim 3, in which the said recesses are downwardly open in the position of use.

5. A removable platform stand as claimed in any of Claims 2, 3 or 4, in which the said recesses have a cranked shape.

6. A removable platform stand as claimed in any preceding Claim, in which the platform is rigidly (and permanently) secured to the side supports.

7. A removable platform stand as claimed in Claim 6, in which the platform and the side supports are integrally formed by folding from a single blank of sheet metal.

8. A removable platform stand as claimed in any of Claims 2 to 7, in which each side support has two recesses for engagement by respective adjacent rungs of the ladder.

9. A removable platform stand as claimed in any preceding Claim, in which the platform projects substantially on either side of the rung with the said side supports on one side and the platform projecting at least to some extent on the other side.

1 0. A removable platform stand as claimed in any of Claims 1 to 6 or 8, in which the platform is pivotally mounted on the side supports to allow a user's foot to displace it from a rung to stand directly on the rung.

11. A removable platform stand as claimed in Claim 10, in which the platform is formed in two parts hingedly mounted together with the hinge joining the two platform parts extending parallel to the pivot axis of the pivotal connection between the platform and the side supports.

1 2. A removable platform stand as claimed in Claim 11, in which a first of the two hingedly joined platform parts is pivoted to the side supports and turntable in a first directional sense about the pivots between a lowered, working position and a raised position, and the second of the two hingedly joined platform parts is hinged to the first part and turnable about the hinge axis in the opposite sense from the first in moving from the lowered, working position to the raised position.

1 3. A removable platform stand as claimed in any preceding Claim, in which the platform is adapted to receive a board or plank to form a trestle with a suitable or similar support for the other end of the said board or plank.

14. A removable platform stand as claimed in any preceding Claim, in which the platform is formed in two parts with a first or front portion being hingedly mounted to a second or rear portion which is rigidly secured to the side supports, the front portion being turnable between a working position in which it lies substantially coplanar with the rear portion and a raised position overlying the rear portion to allow a user to climb past without difficulty.

1 5. A removable platform stand as claimed in Claim 14, in which the first portion is resiliently biased towards the said working position.

1 6. A removable platform stand for a ladder positionable at one or a plurality of locations coincident with the rungs along the ladder to provide a wider area of support for a user than a rung of the ladder itself, enabling the user to stand on the ladder for extended periods without discomfort, comprising a generally flat platform portion carried on side supports having attachment means for attaching the stand to a rung of a ladder, in which the attachment means of the side supports are adjustable whereby to vary the inclination of the plane of the platform with respect to the plane defined by the two stiles of the ladder.

1 7. A removable platform stand as claimed in Claim 16, in which the attachment means comprise two recesses or notches in each side plate for receiving rungs of the ladder when the platform is fitted thereto, one such recess in each side plate having an associated retaining member serving to retain the rung of the ladder at a selected position along its length to determine the inclination between the platform and the ladder.

1 8. A removable platform stand as claimed in Claim 16 or Claim 17, in which the retaining member comprises a pivoted bifurcated plate having arms spaced by a distance approximately equal to the thickness of the ladder rungs.

1 9. A removable platform stand as claimed in any of Claims 16 to 18, in which the pivoted bifurcated plate has detent means for determining its angular position about the pivotal attachment to the associated side plate.

20. A removable platform stand as claimed in any of Claims 1 6 to 19, in which the detent means comprise an arcuate array of openings in either the side plate or the retaining member and a cooperating opening in either the retaining member or the side plate, and a pin for insertion between aligned openings in the two said members at each selectable relative inclination between the retaining member and the side plate.

21. A removable platform stand as claimed in any of Claims 1 6 to 20, in which the retaining member is infinitely adjustable between end positions.

22. A removable platform stand as claimed in Claim 21, in which the retaining member has associated screw adjusting means for determining the relative inclination between the retaining member and the side plate.

23. A removable platform stand as claimed in any of the preceding claims and substantially as hereinbefore described with reference to, and as shown in, any of the Figures of the accompanying drawings.