GB2089873A - Convertible ladder - Google Patents

Abstract

The apparatus of the invention comprises a step ladder having first and second ladder portions 1, 5 which may, in alternative configurations, be: i) aligned for use as an ordinary ladder ii) used as a step ladder iii) turned for support by a brace 9 and a support 13 with the first ladder portion 1 horizontal for use as a platform. <IMAGE>

Description

SPECIFICATION Supporting apparatus The present invention relates to supporting apparatus.

Presently there are available a number of apparatuses for use in household maintenance and construction work by both amateur handymen and professional builders. Examples of such apparatuses are i) an ordinary ladder, i.e. a straight ladder which requires support from a wall for example against which the ladder is stood, ii) a step ladder, i.e. a short ladder having its own supporting leg which together form a selfsupporting invert V, iii) a tressel-supported platform, iv) a wall-papering table, v) a conventional work bench, vi) a special collapsible work bench sold by Black and Decker under the name "Workmate".

The supporting apparatus of the invention has been developed in a project to incorporate features from many existing supporting apparatuses into a single supporting apparatus, and is based on the concept of turning a step ladder to a position where its ladder portion is held horizontally and can be used as a platform.

The supporting apparatus of the invention comprises:- a first ladder portion having a pair of longitudinal rails and a plurality of rungs fixed between the rails, a second ladder portion having a pair of longitudinal rails and a plurality of rungs fixed between the rails, the portions being pivotally connected together at a pivotal end of each portion, a first brace for bracing apart the opposite ends of each ladder portion, whereby the two ladder portions define and acute included angle, and a support for supporting the pivotal ends of the ladder portions such that when the ladder portions are braced apart with the opposite end of one portion on the ground, the other portion is supported substantially horizontal.

In the preferred embodiment of the supporting apparatus, as described below, the supporting apparatus can be used in the following configurations; 1 ) a step ladder 2) an ordinary ladder of twice the length of the step ladder, 3) an ordinary ladder with an extension permitting the top rung of the ordinary ladder to be stood on and enabling work to be carried out behind the top rung which is held away from the wall, for instance, against which the ladder is stood.

4) a platform for standing on which is adjustable between two different heights, 5) a wall-papering table, and 6) a work bench.

To help understanding of the invention this preferred embodiment will now be described with reference to the accompanying drawings in which: Figure 1 is a perspective view, with some parts exploded, of the preferred supporting apparatus configured for use as a bench/wall-papering table/platform: Figure 2 is a sectional side view of the configuration of Figure 1; Figure 3 is a side view of the supporting apparatus in a low level platform configuration; Figure 4 is a side view of the supporting apparatus in a collapsed configuration; Figure 5 is a detailed end view of a clamp attachment; Figure 6 is a detailed sectional side view of a fastening attaching a platform board to the supporting apparatus at A in Figure 2; Figure 7 is a detailed sectional side view of a fastening attaching a stretcher of a support to a rung B in Figure 4;; Figure 8 is a detailed side view at C in Figure 2 of a brace member attached to a longitudinal rail; Figure 9 is a sectional end view in the direction of arrow /X in Figure 8; Figure 10 is a sectional oblique plan view on line X-X in Figure 8; Figure 11 is a detailed side view at D in Figure 2 of a support leg attached to a longitudinal rail; Figure 12 is a sectional end view in the direction of arrow X/ in Figure 1 1; Figure 1 3 is a perspective view of the supporting apparatus of Figure 1 configured for use as a step ladder; Figure 14 is a perspective view of the supporting apparatus of Figure 1 configured for use as an ordinary ladder; and Figure 15 is a view similar to the Figure 14 view showing a brace used as an extension of the ordinary ladder.

Referring first to Figures 1, 2 and 3, which show the supporting apparatus in the table/bench/platform configuration, the apparatus can be thought of as a step ladder turned flat and supported at both ends. Its main components, ali of aluminium, are a first ladder portion 1 having two longitudinal rails 2, 3 and rungs 4, a second ladder portion 5 also having two longitudinal rails 6, 7 and rungs 8, a brace 9 having two brace members 10, 11 and a cross-piece 12 and a support 13 also having two support legs 14, 1 5 and a stretcher 1 6. The first ladder portion 1 is supported horizontally above the ground by the support 13 at its pivotal end 1 7 at which it is pivoted to the second ladder portion 5.At its other end 18, the first ladder portion 1 is held horizontal by the brace 9, which is pivoted to the second ladder portion 5 close to its other end 19 which is itself resting on the ground G.

As may be seen by comparing Figures 2 and 3, the apparatus may be adjusted between its high level configuration Figure 2 and its low level configuration, Figure 3. However, in both configurations the two ladder portions 1, 5 define an acute included angle a therebetween.

Adjustment of the brace 9 is achieved by engaging either of two bolts 20, 21, provided in each brace member 1 0, 11 at different positions, in a key slot 22 provided in each longitudinal rail 2, 3, see Figures 8, 9, and 10. To allow the adjustment to be made without interference of the bolt heads 23a with the longitudinal rails prior to engagement in the key hole slot, the brace members are formed of a rectangular extrusion having a channel 23 dimensioned to receive the bolt heads 23a as shown dotted in Figure 9. The bolts are provided with wing nuts 24 and are peened to prevent loss of the wing nuts. As shown in Figure 2, the bolts 20 further from the second ladder portion 5 are engaged in the key hole slot 22 for the high level and, as shown in Figure 3, the bolts 21 nearer the second ladder portion 5 are engaged in the key hole slot 22 for the low level.

Adjustment of the support 13 is achieved a little differently. As shown in Figures 11 and 12, a plate 25 is riveted to the outside of each first portion longitudinal rail 2, 3. The pivotal ends of the second ladder portion longitudinal rails 6, 7 are pivotally pinned to the plates 25 by pins 25a.

The support legs 14, 1 5 are also pivotally pinned to the plates 25 and to the respective longitudinal rails 2, 3 by pins 26 are a position 27 spaced from the mid point of the support legs by approximately half the height difference between the high platform level and the low platform level. Thus when one end of the support legs is on the ground the first ladder portion 1 is supported at one level, and when the other end of the support legs is on the ground the first ladder portion is supporting at the other level as shown in Figures 2 and 3. The support legs are each equipped with two bolts 28, 29 at equal radii to each other but on opposite sides of the pin 26. Each plate 25 has a key hole slot 30 also at the same radius. According to which level is required the support legs are rotated for either of the bolts to be engaged in the key hole slot.The "bottom" of the key hole slot in each plate is positioned slightly further from the pin 25a than a line L through the pin 26 perpendicular to the length of the first ladder portion 1. Thus when as is intended the first ladder portion is supported horizontally the support legs are inclined slightly outward in a downwards direction, with the result that whichever bolt 28, 29 is engaged in the slot 30, it is urged against the "bottom" of the slot.

The support legs are formed of the same extrusion as the brace members with the same channel 23 to accommodate the heads 23a of the bolts 28, 29 to avoid them fouling the longitudinal rails 2, 3 during rotation of the support legs. Again the bolts are equipped with wing nuts 24 and are peened at their ends.

Returning to Figure 1, the platform can be seen to be provided with a board 31, for use as a walking board or wall-papering board for example.

It is provided with holes 32 for accommodating pegs for use as planing stops for example. The board is attached to the first ladder portion by two fastenings 33 consisting of wing nuts 34 and uneven leg U-clips 35 on peened end coach bolts 36 extending through the board 31. The short leg of the U-clips 35 each engage behind the front flange 37 of one of the rungs 4. To secure the attachment, the flanges 37 are provided with inturned rims 38 held captive with the U-clips when the wings nuts 34 are tightened.

A clamp attachment 39 which may be secured anywhere along either longitudinal rail 2, 3 is shown in Figure 5. These rails are formed of an H section extrusion with rungs 4 riveted in one channel 40 and the clamp attachment accommodatable in the other channel 41. This channel 41 opens sideways of the ladder portion and has rims 42 directed towards each other at either side of the mouth of the channel, see also Figure 9. These rims 42 captivate a clamp back plate 43 which has welded on a stud 44 carrying a clamp front plate 45, a washer 46 and a tightening unit 47. The clamp attachment 39 is free to move along the channel 41 until the nut 47 is tightened. As shown in Figure 5 the clamp attachment may be provided with a further clamp 48 for clamping down onto the board 31.The further clamp has an anchor plate 49, held as if it were a workpiece in the attachment 39, to which is welded a stud 50 carrying a similar clamp plate 51, washer 52 and tightening unit 53. Normally two clamp attachments 39 and further clamps 48 are provided in a tool box 54 provided by plating the other end 1 8 of the first ladder portion 1. The tool box has a hinged door 55 equipped with a lock.

Turning now to Figure 13, the supporting apparatus is there shown in its step ladder configuration. The two ladder portions 1 and 5 are held at a slightly larger acute angle than in either of the platform configurations, Figures 2 and 3, by a hook 56 of steel rod which is journalled in the longitudinal rail 6 and hooks into a hole in the rear flange of the channel 40 of the longitudinal rail 2.

The brace 9 could be used for holding the ladder portions in the step ladder configuration but it would have to be considerably ionger than as shown. In fact the brace 9 is clipped to lie along the second ladder portion 5 in the step ladder configuration by a spring-loaded U shaped clip 57 provided on either brace member 10 or 11. The support 1 3 is also not used in the step ladder configuration and lies along the first ladder portion. Its stretcher 1 6 is fastened to one of the rungs as shown in Figure 7. The stretcher 1 6 is an aluminium strip having a part of itself flanged down at 58. The opposite edge lies below the corner 59 of the rung 4 to which the stretcher 1 6 is fastened by a fastening 33 identical to that by which the platform board is fastened in the platform configuration.

Figure 14 shows the supporting apparatus in an ordinary ladder configuration with the second ladder portion swung round to align with the first ladder portion. Between the extremities 60 of the longitudinal rails 6, 7 abut the rear flanges of the channels 40, 41 in the longitudinal rails 2, 3 thus providing the ladder with stability when stood against a wall W. To hold hold the ladder portions in their aligned position for manoeuvring, an L-shaped clip 61, is provided on the portion of the hook 56 extending through the long-rail 6. One arm of the L clip has the hook 56 passing through it so that the clip can be pivoted over the extremity of the rear flange of the channel 40 in the Figure 14 configuration so that the other arm engages the flange.

Figure 1 5 shows a configuration similar to that of Figure 14 except that the brace 9 is swung around to form an aligned extension of the second ladder portion 5 to enable the full length of the second ladder portion 5 to be used. The brace members 10, 11 bear against pegs 62, see Figure 14, provided at the end of the second ladder portion. The U clip 57 clips over one peg 62 to maintain the brace 9 in its aligned extension position for manoeuvring of the ladder. It should be noted that the cross-piece 1 2 is not intended to be rung but may be used as a hand grip.

The invention is not intended to be restricted to the details of the above described embodiment.

For instance the platform board could be permanently attached to the first ladder portion if it were attached to the back side thereof and the second ladder portion is arranged to pivot from one side of the first ladder portion to the other.

This is the arrangement shown in the priority application no. 8041286.

Claims (24)

1. Supporting apparatus comprisingl a first ladder portion having a pair of longitudinal rails and a plurality of rungs fixed between the rails; a second ladder portion, having a pair of longitudinal rails and a plurality of rungs fixed between the rails, the portions being pivotally connected together at a pivotal end of each portion; a first brace for bracing apart the opposite ends of each ladder portion, whereby the two ladder portions define an acute included angle; and a support for supporting the pivotal ends of the ladder portions such that when the ladder portions are braced apart with the opposite end of one portion on the ground, the other portion is supported substantially horizontal.

2. Supporting apparatus as claimed in claim 1 wherein the brace is adjustable for bracing the ladder portions apart at differing acute included angles and the support is correpondingly adjustable to support the pivotal ends at differing heights whereby the other portion is supported substantially horizontal.

3. Supporting apparatus as claimed in either preceding claim wherein the pivotal connection at the said pivotal ends is such that the ladder portions can be pivoted to an aligned position for use as an ordinary ladder.

4. Supporting apparatus as claimed in claim 3 wherein the pivotal connection restricts pivoting of the ladder portions beyond the aligned position.

5. Supporting apparatus as claimed in claim 4 wherein it is the first ladder portion which is supportable substantially horizontal by the brace and the support, and the pivotal connection comprises a pivot plate fixed to each longitudinal rail of the first ladder portion a short distance from the extremity of the pivotal end of each said rail and a pin pivotally pinning one of the longitudinal rails of the second ladder portion to a respective one of the pivot plates, the arrangement being such that the longitudinal rails of the second ladder portion abut the longitudinal rails of the first ladder portion between the pivot plates and the said extremities when the two ladder portions are aligned for use as a ladder.

6. Supporting apparatus as claimed in claim 3, claim 4 or claim 5 including a clip for retaining the ladder portions in their aligned position as required.

7. Supporting apparatus as claimed in claim 6 as appendant to claim 5 wherein each longitudinal rail of the first ladder portion has a flange against which the corresponding longitudinal rail of the second ladder portion abuts when the ladder portions are in their aligned position and the clip is L-shaped and pinned via one arm of the L to one of the longitudinal rails of the second ladder portion in such position that it can be turned over the said extremity of the flange to engage with the other arm of the L on the surfaces of the flange opposite from the abutting longitudinal rail of the second ladder portion.

8. Supporting apparatus as claimed in claim 7 wherein the L-shaped clip is pinned by a pin having a hook-shaped extension engageable with the said flange when the ladder portions are disposed at an acute included angle whereby the supporting apparatus may be used as a step ladder.

9. Supporting apparatus as claimed in any preceding claim wherein the support comprises two legs each pivoted to a respective one of the longitudinal rails of the first ladder portion.

10. Supporting apparatus as claimed in claim 9 as appendant to claim 5 as appendant to claim 2 wherein each support leg is pinned by a pin to its own longitudinal rail and the respective pivot plate at a point spaced from the mid-point of the support leg, each pivot plate is equipped with a key-hole bolt slot and each support leg is equipped with a pair of bolts on opposite sides of the said point and at the same radius from pin as the key-hole slot, the arrangement being such that either bolt can be engaged in the slot so that the first ladder portion is supported at differing heights according to which bolt is engaged.

11. Supporting apparatus as claimed in claim 10 wherein each support leg is formed from an extrusion having a channel sized to receive the heads of the said bolts whereby the support legs can be pivoted without interference of the bolt heads with the longitudinal rails of the first ladder portion or with the pivot plates.

12. Supporting apparatus as claimed in claim 10 or claim 11 wherein the support legs are interconnected by a stretcher adapted to be secured against a rung of the first ladder portion when the support is not in use.

13. Supporting apparatus as claimed in any preceding claim wherein the brace comprises two brace members each pivoted to a respective one of the longitudinal rails of the second ladder portion at a position remote from the said pivotal end of the said rail.

14. Supporting apparatus as claimed in claim 1 2, as appendant to claim 2 wherein each brace member is equipped with, at spaced positions, two bolts and each longitudinal rail of the first ladder portion is equipped with one corresponding key-hole bolt slot, the arrangement being such that either bolt can be engaged in the slot so that the first ladder portion is supported at differing heights according to which bolt is engaged.

15. Supporting apparatus as claimed in claim 14 wherein each brace member is formed from an extrusion having a channel sized to receive the heads of the said bolts whereby the brace members can be moved for engagement of the bolts with the key-hole slots without interference of the bolts with the longitudinal rails of the first ladder portion.

1 6. Supporting apparatus as claimed in claim 13, claim 14 or claim 15, wherein the brace members are inter-connected by a cross-piece and the brace members can be pivoted to a position aligned with the aligned first and second ladder portions to form an extension of the said ordinary ladder.

17. Supporting apparatus as claimed in claim 1 6 wherein the longitudinal rails of the second ladder portion are each equipped with a peg at their other ends against which pegs of the respective brace members bear when aligned as the said extension.

18. Supporting apparatus as claimed in claim 1 7 wherein each brace member is equipped with a spring loaded clip for alternatively engaging the respective peg or the respective longitudinal rail of the second ladder portion according to whether the brace members are aligned as a said extension or pivoted to extend along the second ladder portion.

19. Supporting apparatus as claimed in any preceding claim wherein it is the first ladder portion which is supportable substantially horizontal by the brace and the support and the apparatus further comprises a platform board attachable to the first ladder portion.

20. Supporting apparatus as claimed in claim 1 9 wherein the platform board is attachable by means of fastenings engaging a plurality of the rungs of the first ladder portion at angled rims of the rungs.

21. Supporting apparatus as claimed in any preceding claim wherein the longitudinal rails of the first ladder portion are formed from an extrusion having a channel opening sideways of the ladder portion and rims directed towards each other at either side of the mouth of the channel.

22. Supporting apparatus as claimed in claim 22 including at least one clamp attachment engageable in the said channel at the said rims.

23. Supporting apparatus as claimed in any preceding claim including an openable box at the other end of the first ladder portion.

24. Supporting apparatus substantially as hereinbefore described with reference to the accompanying drawings.