GB2605607A - Trestle system with safety barriers - Google Patents

Abstract

A system 100 comprising a plurality of trestles 28 each comprising a pair of uprights 36, 38 connected by a crossmember 30 and at least one tubular post 24a extending above the level of the crossmember. The tubular post comprises a plurality of attachment sockets (20, fig 3) in opposing pairs along the height of the post. The system further comprises a plurality of rails 22 comprising pins complementary to those of the post and the rails are removably attachable between the tubular posts to form a safety barrier. Additionally the system comprises a plurality of elongate extension pieces 10 comprising an axially projecting spigot (14, fig 1) removably received in the upper end of the tubular posts, and a further pair of opposed attachment sockets (20, fig 1) whereby a further rail is removably attachable between a pair of extension pieces. The invention provides a safety rail at a greater height.

Description

TRESTLE SYSTEM WITH SAFETY BARRIERS

This invention relates to trestles ("bandstands") for supporting work platforms used on building sites and the like. Two or more such trestles are usually used together, with the work platform made up of scaffolding boards supported between them. Such trestles are generally used to support work platforms of relatively low height (e.g., 0.23.0 m) as a more convenient alternative to scaffolding.

W02005/124057 describes a system in which each trestle comprises a pair of upright supports connected by a crossmember. Planks or boards are supported between the crossmembers of adjacent trestles to make up the work platform. One of the upright supports of each trestle has an integral upward extension reaching above the crossmember, to which a pair of horizontally extending rails can be attached, positioned one above the other, to form an edge protection safety barrier for the work platform. At its end opposite to the upward extension, the crossmember is provided with a socket for receiving the lower end of a removable upright. Further such rails can be attached to the removable upright to form a further safety barrier at the corresponding edge of the work platform, when required. Matching attachment points on the upward extensions and on the removable uprights are horizontally aligned and the rails are telescopically adjustable in length. Thus, further such rails can be attached between the endmost upright extensions and corresponding endmost removable uprights, to form safety barriers at the ends of the work platform, if required. Different spacings between the trestles can also be accommodated by appropriately adjusting the length of the rails.

While this arrangement can be used to provide the work platform with good edge protection on all four sides, meeting current UK safety regulations for working at height, there are occasions where further enhancement of the edge protection barriers may be required. There is therefore a need for a quick and convenient way to upgrade this edge protection when desired.

Accordingly, the present invention provides a system comprising a plurality of trestles, each trestle comprising: a pair of upright supports connected by a crossmember upon which planks or boards can be supported in use to make a platform; and atleast one tubular post extending above the level of the crossmember, the tubular post comprising a plurality of attachment pins or sockets arranged in opposed pairs spaced from one another along the height of the tubular post; in which the system further comprises a plurality of rails comprising at their opposed ends attachment sockets or pins complementary to those of the tubular post, whereby the rails are removably attachable between adjacent ones of the tubular posts to form a safety barrier, to and in which the system further comprises a plurality of elongate extension pieces each comprising: an axially projecting spigot adapted to be removably slidably received in the upper end of a corresponding one of the tubular posts, and a further opposed pair of attachment sockets or pins corresponding to those of the tubular post, whereby a further rail is removably attachable between a pair of the extension pieces which have their projecting spigots received in the upper ends of a pair of the tubular posts. In this way, the height of the safety barrier can be quickly and easily extended, using minimal additional kinds of components.

The tubular post and the axially projecting spigot may have a substantially square or rectangular cross-section. In this way, the extension pieces and tubular posts may be held fixed against relative rotation about their mutual axis, with their respective pairs of opposed attachment sockets/pins aligned.

Each extension piece may have a tubular end opposite to the axially projecting spigot and of complementary cross-section to the axially projecting spigot. This allows a plurality of extension pieces to be stacked to further increase the height of the safety barrier.

The axially projecting spigot may be formed by swaging an end of the tubular body of the extension piece.

Alternatively, each extension piece may have a tubular body in one end of which the axially projecting spigot is secured. This results in a simple robust construction which is easy to make. The lower end of the tubular body and projecting spigot form a shoulder by which the extension piece can be supported at the correct height, on the upper end of the tubular post The axially extending spigot could be secured in the tubular body by a fillet weld at this shoulder. However, variations in the size of the weld could cause the extension piece to be supported at inconsistent heights. The weld may also cause the tubular body to be to supported on the upper end of the tubular post unevenly around its periphery. The weld may also tend to stick or jam in the upper end of the tubular post and to splay and/or cause wear damage to this upper end through repeated insertion and withdrawal.

The axially extending spigot may be secured in the tubular body by a substantially flush fastening received in a through hole formed in the side of the tubular body. For example, weld or braze material may be deposited in the through hole. This results in a clean, square shoulder where the spigot emerges from the tubular body, for stably supporting the extension piece at the correct height, against the upper end face of the tubular post One of the extension pieces may comprise a hinged connection for mounting a safety gate arranged to provide user access to the work platform, through the extended height safety barrier.

The invention correspondingly provides an extension piece configured and adapted for use in a system as described above, to extend the height of a safety barrier.

For the better understanding of the present invention and some of its optional or features and further advantages, the following description of an illustrative trestle system embodying the invention is provided, referring to the drawings, in which: Fig. 1 is a side view of an extension piece embodying the present invention; Fig. 2 is a top plan view of the extension piece shown in Figure 1; Fig. 3 is a perspective view showing the spigot of the extension piece partly engaged in/disengaged from the top of a tubular post; Fig. 4 is a perspective view of part of an assembled trestle system, with broken lines indicating an upward extension of the safety barriers which is possible through use of extension pieces as shown in the preceding Figures; Fig. 5 is a perspective view from on the work platform, of the assembly of Figure 5, including the extended safety barriers; and Fig. 6 is a perspective view of a safety gate and its mounting for use in the extended safety barrier of Figs. 4 and 5.

Figures 1 and 2 show an extension piece 10 useable to extend the height of a safety barrier in a trestle system embodying the present invention. The extension piece has a main body 12 formed from a length of square hollow section (SHS) mild steel tubing e.g. of 31.75 x 31.75 mm cross-section outside dimensions and 2.03 mm wall thickness.

This may match the corresponding dimensions of tubular posts of the trestle system, as further described below. A spigot 14 projects from a lower end of the main body 12. The spigot 14 may be formed from SHS mild steel tubing e.g. of 25 x 25 mm outside dimensions and 1.5 mm wall thickness. The spigot 14 is partially inserted into the lower end of the main body 12 as indicated by the broken lines in Figure 1. It can be secured in this position by weld or braze material deposited in a through hole 16 formed in the main body 12 and then ground flat. However, any other suitable fastening method may be used, for example a rivet or countersunk threaded fastener, with a head received in the hole 16. Although not essential, such fastening methods leave a clean and square shoulder 18 formed where the spigot 14 emerges from the main body 12. Hence the extension piece 10 may be stably supported at a consistent height when the spigot 14 is inserted into the top of a tubular post, as further described below. The square shoulder 18 is not liable to jam or cause wear or flaring of the post end. Alternatively, the spigot 14 and shoulder 18 may be formed by swaging a lower end of the main body 12 to suitably reduced dimensions. The upper end of the main body 12 may be left open so that, if desired, the spigot 14 of a further similar extension piece 10 may be inserted into it, to further extend the height of the safety barrier.

A pair of attachment sockets 20 are welded or otherwise suitably fastened on opposite sides of the upper end of the main body 12. The attachment sockets 20 may be positioned and dimensioned to match those present on the safety rail supporting posts of the rest of the trestle system. Then standard safety rails 22 of the same kind as used elsewhere in the trestle system may be held in place between adjacent extension pieces 10, as further described below. The attachment sockets 20 may be formed for example from 40 mm lengths of SHS mild steel tubing of 20 x 20 mm outside dimensions and 2.0 mm wall thickness. A suitable paint coating or like decorative and/or corrosion inhibiting finish may be applied to the completed extension piece, for example an electrostatically applied polyester powder coating. The length of the main body 12 may be e.g., 460 mm, to provide a corresponding increase in the height of the edge protection safety barrier of the trestle system.

Figure 3 shows the spigot 14 of an extension piece 10 partly inserted into, or partly withdrawn from, the top end of a tubular post 24 of complementary square cross section (e.g. matching the cross-section of the extension piece main body 12). The matching non-round cross-sections of the spigot 14 and post 24 prevent the post 24 and extension piece 10 from rotating relative to one another about their mutual axis. The attachment sockets 20 on the extension piece 10 (not visible in Figure 3) may therefore be kept in vertical alignment with the corresponding attachment sockets 20' on the post 24. Substantially identical safety rails 22 are provided with transversely extending attachment pins 26. These attachment pins 26 may be inserted vertically downwards through the attachment sockets 20 or 20', to secure and support each rail 22 between a pair of adjacent extension pieces 10 or posts 24. The rails 22 may be telescopically or otherwise adjustable in length, for example as described in W02005/124057 or GB2378978, to accommodate different spacings between the posts 24 or extension pieces 10.

Figure 4 shows a trestle system 100 equipped with edge protection safety barriers 110 30 which are (or are to be) upwardly extended as indicated in broken lines 112, with the assistance of extension pieces 10 as described above with reference to the preceding Figures. The system includes trestles 28 which have crossmembers 30, on and between which planks 32 are supported to form a work platform 34. An upright 36 on one side of each trestle 28 extends above the level of the crossmember 30 to form an upward extension or post 24a. At its opposite end, each crossmember 30 has a socket 38 for receiving a removable post 24b. The posts 24a and 24b each carry a firstpair of opposed attachment sockets 20' at substantially the same elevation, about half-way up their height The posts 24a and 24b extend to substantially the same height as each other above the work platform 34 and each carry a second pair of opposed attachment sockets 20' near to their top ends. The post 24 shown in Figure 3 may therefore represent a more detailed view of either the post 24a (trestle upright upward extension) or of the to (removable) post 24b shown in Figure 4. Transversely extending attachment pins 26 at the opposite ends of safety rails 22 may be received in attachment sockets 20' positioned at the same height on adjacent posts 24a, to form the safety barrier at the edge of the work platform 34 in the foreground of Figure 4. Similarly, transversely extending attachment pins 26 at the opposite ends of safety rails 22 may be received in attachment sockets 20' of the same height on adjacent posts 24b, to form the safety barrier at the edge of the work platform 34 in the background of Figure 4. At either end of the work platform 34, further safety rails 22 may be supported and secured between attachment sockets positioned at the same height on the posts 24a and 24b, to form the safety barrier there. (Only one end of the work platform 34 is visible in Figure 4). Access to the work platform 34 may be provided via a foldable staircase 40 with demountable handrails 42. A safety gate 44 may be provided in the safety barriers 110 at the top of the staircase 40. The safety gate 44 may be extended upwardly as shown at 46 in Figure 4, to match the extended height of the safety barriers 110.

Figure 5 shows the trestle system and enhanced edge protection barriers 110 viewed as if standing on the work platform 34, looking towards one end of it. The extension pieces 10 received in the top ends of the posts 24a and 24b can be seen, supporting a third, top row of safety rails 22, above first and second rows of safety rails 22 supported directly by the posts 24a and 24b. The enhanced height safety gate 44 can also be seen.

Figure 6 shows the enhanced height safety gate 44 in more detail. It comprises an extended top portion not present in a standard height safety gate. The enhanced height safety gate 44 is mounted to a modified extension piece 10a by upper and lower extension piece brackets 48a and 48b, slanted hinge pin SO, and a slanted journal tube 52 attached to the gate 44 by a gate bracket 54.

A latch bracket has an inverted T-shaped body 56. A top plate 58 of the latch bracket caries a spigot (not visible in Figure 6) which extends downwards from the top plate 58, parallel to the vertical limb of the inverted T-shaped body 56. The latch bracket to spigot is received in the open top end of the extension piece 10. The latch bracket is thereby suspended from the extension piece 10 by the spigot and top plate 58, leaving the attachment sockets 20 of the extension piece 10 free and unobstructed, for the reception of attachment pins 26 of safety rails 22. A pair of stabiliser plates 60 (only one of which is visible in Figure 6) attached to the vertical limb of the inverted T-shaped body embrace the extension piece 10, to hold the latch bracket against it The latch bracket is further secured in place by one of the safety rails (referenced 22' in Figure 6) whose end is received in a first latching hook 62a attached to one end of the horizontal limb of the inverted T-shaped body 56. This end of the safety rail 22' is also secured to one of the attachment sockets 20' of the post 24a below the extension piece 10.

A second latching hook 62b attached to the other end of the horizontal limb of the inverted T-shaped body 56 holds the safety gate 44 in the closed position. When it is desired to open the safety gate 44, it can be lifted out of the latching hook 62b, rising up the hinge pin 50 on the journal tube 52. The safety gate 44 can only be opened inwards, towards the work platform 34. It is prevented from being opened outwards by the horizontal limb of the inverted T-shaped body 56 and the second latching hook 62b. After being opened and released, the slanted hinge pin 50 and journal tube 52 cause the safety gate 44 to fall automatically towards the closed position under its own weight A lead-in ramp extending from the second latching hook 62b (not visible in Figure 6) allows the safety gate 44 to rise up over and then drop into the second latching hook 62b at the end of this fall. Note that the latch bracket is mirror-symmetrical, so that the safety gate 44 can also be mounted to the right of it, rather than to the left as shown in Figure 6 (in which case the latching hook 62b will receive a safety rail end and the latching hook 62a will receive the safety gate 44 in its closed position).

Claims (10)

1. CLAIMS1. A system comprising a plurality of trestles, each trestle comprising: a pair of upright supports connected by a crossmember upon which planks or boards can be supported in use to make a platform; and at least one tubular post extending above the level of the crossmember, the tubular post comprising a plurality of attachment pins or sockets arranged in opposed pairs spaced from one another along the height of the tubular post; to in which the system further comprises a plurality of rails comprising at their opposed ends attachment sockets or pins complementary to those of the tubular post, whereby the rails are removably attachable between adjacent ones of the tubular posts to form a safety barrier, and in which the system further comprises a plurality of elongate extension pieces each 15 comprising: an axially projecting spigot adapted to be removably slidably received in the upper end of a corresponding one of the tubular posts, and a further opposed pair of attachment sockets or pins corresponding to those of the tubular post, whereby a further rail is removably attachable between a pair of the extension pieces which have their projecting spigots received in the upper ends of a pair of the tubular posts.
2. 2. A system as claimed in claim 1, in which the tubular post and the axially projecting spigot have a substantially square or rectangular cross-section.
3. 3. A system as claimed in claim 1 or 2, in which each extension piece comprises a tubular end opposite to the axially projecting spigot and of complementary cross-section to the axially projecting spigot.
4. 4. A system as claimed in any preceding claim, in which the axially projecting spigot is formed by swaging an end of the tubular body of the extension piece.
5. 5. A system as claimed in any of claims 1-3, in which each extension piece comprises a tubular body in one end of which the axially projecting spigot is secured.
6. 6. A system as claimed in claim 5, in which the axially extending spigot is secured in the tubular body by a fastening received in a through hole formed in the side of the tubular body.
7. 7. A system as claimed in claim 6, in which the fastening comprises weld or braze material deposited in the through hole.
8. 8. A system as claimed in any preceding claim, in which a lower end of the tubular body and the projecting spigot form a shoulder by which the extension piece can be supported on the upper end of the tubular post
9. 9. A system as claimed in any preceding claim, in which one of the extension pieces comprises a hinged connection for mounting a safety gate arranged to provide user access to the work platform.
10. 10. An extension piece configured and adapted for use in a system of trestles as claimed in any preceding claim.