NZ580246A - Scaffold stair foldable and with platform surface free of side obstruction - Google Patents

Abstract

A stair is disclosed having a platform, an upper pair of beams, a lower pair of beams, a plurality of steps extending transversely between the beams, the steps being pivotally secured to each beam, the beams being pivotal with respect to the platform such that the beams, the steps and the platform can assume a substantially flat disposition for storage and wherein the beams can subsequently be swung with respect to the platform such that the stair assumes an erect functional disposition, the stair having an upper and lower connections adapted to enable it to engage the bars of a scaffold structure when in use, and such that the standing surface of the platform is substantially clear from side obstruction.

Description

580246 1 Patents Form No. 5 THE PATENTS ACT 1953 COMPLETE SPECIFICATION SCAFFOLD STAIR I/We, Bruce Joseph Senior, a New Zealand citizen, of 43 Niven Street, Onekawa, Napier, New Zealand, hereby declare this invention for which l/we pray that a patent 25 may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: 580246 2 Title Scaffold Stair Field of Invention This invention relates to a scaffold stair.

Background It is known to use ladders or the like with scaffolding. It is an object of the present invention to go at least some way toward providing an alternative to such known 10 products.

Summary of Invention According to one aspect of the invention there is provided a stair having a platform, an upper pair of beams, a lower pair of beams, a plurality of steps extending 15 transversely between the beams, the steps being pivotally secured to each beam, the beams being pivotal with respect to the platform such that the beams, the steps and the platform can assume a substantially flat disposition for storage and wherein the beams can subsequently be swung with respect to the platform such that the stair assumes an erect functional disposition, the stair having upper and lower 20 connections adapted to enable it to engage the bars of a scaffold structure when in use.

Optionally the upper connection comprises a pair of hooks.

Optionally the lower connection comprises a pair of hooks.

Optionally the stair has two pairs of link arms, one pair of these extending from the lower pair of beams to the platform and the other of these extending from the upper pair of beams to the platform, each link arm pivotally connected to a respective one 30 of the beams and pivotally connected to the platform.

Optionally the stair is formed such that the standing surface of the platform is substantially clear from side obstruction.

Optionally the stair has a second platform arranged at an end of the beams remote from the first mentioned platform. 580246 3 Optionally the upper and lower pairs of beams can be releasably locked at a selection of angles with respect to the platform(s), and wherein for each selection the steps and the platform(s), are substantially horizontal.

General Description of the Drawings Some preferred embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a set of stair in a functional disposition; Figure 2 is a perspective view of a stair in a substantially folded down disposition; Figure 3 is a perspective view of a similar stair fitted with removable hand rails; 15 and Figures 4 & 5 are perspective views illustrating detail of the stair of figure 3.

Detailed Description Referring to figure 1, the stair 1 is designed for use as part of a scaffolding structure 20 to provide a convenient way to walk between upper and lower levels of scaffolding. Figure 1 shows the stair when in a normal in-use disposition (the surrounding scaffolding is omitted for clarity). Figure 2 shows the stair 1 when in a compact folded down disposition, ready for transport or storage.

Referring to figure 1, the stair has a series of steps 2 spaced apart and proceeding in sequence from the bottom to the top of the stair. The steps 2 are each held in a horizontal disposition by a pair of upper diagonal beams 3a and 3b and a pair of lower diagonal beams 4a and 4b. Each side of each step 2 is pivotally attached to one of the upper and one of the lower diagonal beams by way of pivot connections 5. 30 When the diagonal beams are locked in place the steps are correspondingly locked against pivoting movement.

As shown most clearly in figure 1, the stair 1 has lower and upper platforms 6 and 7. The lower platform has a pair of support arms 8a and 8b extending rearwards and 35 which support a pair of walking panels 9 and 10. It can be seen from figure 1 that the panels 9 and 10 provide a walking or standing surface which is clear of side 580246 4 obstruction. A pair of rear struts/link arms 11a and 11b pivotally connect the support arms 8a and 8b to the lower diagonal beams 4a and 4b respectively. A pair of forward struts/link arms 12a and 12b similarly connect the support arms 8a and 8b to the upper diagonal beams 3a and 3b respectively. When the stair is caused to 5 assume its collapsed figure 2 disposition the struts 11a, 11b, 12a and 12b swing downwardly and rearwards until they lay substantially parallel to the support arms 8a and 8b.

The upper platform 7 need not be constructed the same as the lower one, although if 10 preferred it can be, with appropriate adjustments to enable it to function at the top part of the stair. However in the embodiment shown in the accompanying drawings the upper platform is simply secured to the upper end of the diagonal beams by way of two side pivot connections 13 per side which enable the upper platform to pivot and lay substantially parallel to the diagonal beams, ie when the stair is in its figure 2 15 disposition.

Removable locking pins 14 may be used to lock the stair in its figure 1 in-use disposition. These locking pins pass through the diagonal beams and the struts 11a, 11b, 12a and 12b and upper platform 7.

Referring to figure 1, a pair of hook connectors 15 is secured at each end of the stair to enable it to be releasably coupled to the bars of a scaffolding structure.

In some embodiments of the invention the diagonal beams can be locked at a 25 selection of angles with respect to the platforms to accommodate situations where the scaffold levels between which the stair is used are at varying vertical distances from one another, eg from one job to the next. This may be facilitated by providing a selection of holes for the removable locking pins 14.

As shown in figure 3, in some embodiments of the invention separate detachable left and right side hand rails 16 may be secured to the upper and or lower diagonal beams for safety. Figures 4 and 5 show further detail of the stair of figure 3, and in particular the manner in which the upper platform 7a is associated with the diagonal beams. In this embodiment there is a joint 17 between each lower diagonal beam 18 35 and the upper platform. When the joint is unlocked the upper platform 7a is able to swing about pivot points 19 between each upper diagonal beam 20 and the upper platform. Such swinging movement can be used to position the upper platform in a 580246 substantially flat state with respect to the rest of the stair when in a folded up disposition. To facilitate the locking and unlocking of the joints 17 each joint has a pair of plates 21 either side of each lower diagonal beam and a removable locking pin 22.

While some preferred forms of the invention have been described by way of example it should be appreciated that modifications and improvements can occur without departing from the scope of the appended claims. 580246 6

Claims (7)

Claims

1. A stair having a platform, an upper pair of beams, a lower pair of beams, a plurality of steps extending transversely between the beams, the steps being 5 pivotally secured to each beam, the beams being pivotal with respect to the platform such that the beams, the steps and the platform can assume a substantially flat disposition for storage and wherein the beams can subsequently be swung with respect to the platform such that the stair assumes an erect functional disposition, the stair having upper and lower connections adapted to 10 enable it to engage the bars of a scaffold structure when in use, the stair formed such that the standing surface of the platform is substantially clear from side obstruction.

2. A stair according to claim 1, wherein the upper connection comprises a pair of 15 hooks.

3. A stair according to claim 1 or 2, wherein the lower connection comprises a pair of hooks. 20

4. A stair according to claim 1, 2 or 3, having two pairs of link arms, one pair of these extending from the lower pair of beams to the platform and the other of these extending from the upper pair of beams to the platform, each link arm pivotally connected to a respective one of the beams and pivotally connected to the platform. 25

5. A stair according to any one of the preceding claims, having a second platform arranged at an end of the beams remote from the first mentioned platform.

6. A stair according to any one of the preceding claims, wherein the upper and lower 30 pairs of beams can be releasably locked at a selection of angles with respect to the platform(s), and wherein for each selection the steps and the platform(s), are substantially horizontal.

7. A stair according to any one of the preceding claims substantially as herein 35 described. 580246 7 A stair substantially as herein described with reference to figures 1 and 2, or figure 3. A scaffolding structure fitted with a stair according to any one of the preceding claims, the stair providing a walkway between two levels of the scaffolding. Bruce Joseph Senior By His Attorney A.J. Pietras & Co