GB2439156A

GB2439156A - Safety rail standard

Info

Publication number: GB2439156A
Application number: GB0614998A
Authority: GB
Inventors: David Jonathan Gibbs
Original assignee: Access Technologies Ltd
Current assignee: Access Technologies Ltd
Priority date: 2006-06-12
Filing date: 2006-07-28
Publication date: 2007-12-19
Also published as: GB0614998D0; GB0611516D0

Abstract

The invention relates to a standard for use with horizontal safety rails and comprises an elongate section 19 and a rail location section 15 having a through-bore 17 which tapers from either the centre 22 to the ends 23, 24 or from one end 23 to other end 24. The bore is defined by two inner edges 25, 26 which may be a convex shape. The shape of the bore allows safety rails to be raked at an angle and reduces the deposits of zinc during plating and reduces the difficulty of feeding a horizontal rail through the bore. A later embodiment relates to a safety rail assembly comprising said standard.

Description

1 2439156

SAFETY RAIL STANDARD

This invention relates to a standard, which may also be referred to as an upright or stanchion, of a kind for use with a safety rail which extends generally horizontally or inclined for the purpose of forming a safety rail assembly such as may be used for a walkway, ramp or stairway.

The invention relates also to a component for use in constructing a safety rail standard and to a safety rail assembly comprising a standard or component of the present invention.

One well established method for constructing a standard comprises welding an apertured part-spherical solid ball section between two aligned sections of an elongate member such as a solid rod or a tube, and with another ball section being welded to the upper end of an elongate section. Alternatively the complete standard may be formed by solid forging. To form the safety rail assembly a pair of safety rails of a safety rail assembly can be fed through the respective apertures of the ball sections, thereby each to be supported by the standard.

If the standard is to be used to construct a safety rail assembly for a walkway, the longitudinal axis of each aperture is orientated to extend perpendicular to the length of the standard, whilst in the case of a standard to be used for a ramp or stairway, and with the standard mounted vertically, the longitudinal axis of each aperture is orientated to be inclined to the length of the standard at an angle corresponding to the inclination of the ramp or stairway relative to the vertical direction.

The standard typically is required to be suitable for use in external environments, and including coastal regions where the standard will be exposed to salt spray. To provide protection in external environments the standard is galvanised, usually by a hot dip galvanising process.

Although the galvanising treatment is effective to provide a standard with long-term corrosion resistance, it does suffer the disadvantage that localised excess deposits of zinc can occur within the bore of each solid ball section.

That can lead to a restriction in the bore diameter and thus a difficulty in feeding horizontal rails through the bore section apertures to form a safety rail assembly. Because the standards usually are hung or supported vertically for treatment, any excess zinc deposits do not readily drain from the ball sections, particularly if the apertures extend substantially perpendicularly relative to the length of the standard.

The risk of excess zinc deposits accumulating in the bore of a ball section can be minimised by laying the standard horizontally for galvanising. That, however, requires also that the standard is carefully positioned such that the bore of each ball section is sufficiently inclined to the horizontal to ensure that during a hot dip galvanising process excess zinc deposits drain away from the bore. There is also the disadvantage that, in contrast to a standard which has been hung or supported vertically from one end in a conventional manner, if the standard is supported horizontally there is a tendency for excess deposits to accumulate at those positions where the standard is supported along its length. This results in an adverse effect on the appearance of the finished product.

Although the problem of localised excess deposits arises particularly in the case of standards that are protected by galvanising, similar difficulties can arise when other types of surface treatment are applied to a standard.

Another difficulty often encountered when constructing a safety rail assembly is that a walkway may not be truly horizontal, or that the on-site angle of inclination of a ramp or stairway differs slightly from that envisaged at the time of constructing or selecting a suitable standard. This difficulty can arise both with standards that have solid ball sections as well as those having hollow ball sections. The problem sometimes can be addressed by slightly inclining the standards relative to the vertical, but that is visually undesirable.

Yet another difficulty which is encountered is that of not being able to feed pre-bent safety rails through the ball sections.

The present invention seeks to provide an improved safety rail standard, safety rail component and safety rail assembly, and also a method for the construction of a safety rail standard, in which at least some of the aforedescribed difficulties are mitigated or overcome.

In accordance with one aspect of the present invention there is provided a standard for a safety rail, said standard comprising an elongate section and a rail location section having a through-bore, the cross-section of said through-bore being greater at at least one end thereof than at a position between the ends of the through-bore or at the other end of the through-bore.

The rail location section may be a solid or a hollow formation. If it is a solid formation, the cross-section of the bore may be smaller at a position between the ends of the bore than at one or each end of the bore. Thus the bore of the rail location section may increase in cross section from a position between the ends of the bore to each end of the bore.

The standard maybe an integral assembly comprising an elongate section and a rail location section which have been united together for example by welding. Alternatively both sections may be formed together, integrally with one another, for example by solid forging.

In accordance with another aspect of the present invention a method of manufacture of a standard for a safety rail assembly comprises providing an elongate section and a solid type rail location section having a through-bore, welding the rail location section to an end of elongate section and then subjecting the welded assembly to a surface protection treatment, wherein the bore of the rail location section increases in cross-section from a position between the ends of the bore to each end of the bore.

The bore of the rail location section may extend substantially perpendicular to the length of the elongate section. Alternatively the bore of the rail location section may be inclined relative to the length of the standard, for example by at least 300, and more typically by at least 50 .

The standard may be of a type in which, as considered in the direction of the length of the through-bore of the rail location section, the elongate section has a thickness which is at least equal to the axial length of the through-bore.

More typically, however, the elongate section may have a thickness in said direction which is less than said axial length of the through-bore, for example less than 90%, or even less than 85% of said axial length. Constructions in which said percentage is below for example 80% are also contemplated.

The present invention is of particular benefit in the case of a rail location section for which the axial length of the through-bore is greater than the minimum cross-sectional dimension of the through-bore. It is of especial benefit, for allowing ease of use of pre-bent safety rails, in the case of a rail location section having an axial length which is at least 10%, for example at least 20%, greater than the minimum cross-sectional dimension of the bore.

Preferably the minimum cross-sectional dimension of the through-bore, at at least one end thereof, is in the range 105% to 140% of the minimum cross-sectional dimension at a position between the ends of the bore. More preferably said range is between 110% and 125%.

The invention provides also a rail location section and a standard comprising a solid type rail location section in which the bore of the rail location section increases in cross-section from a position between the ends of the bore to each end of the bore. Preferably said cross-section increases from a position which is mid-way between the ends of the bore.

The invention further provides a safety rail assembly comprising a standard in accordance with the present invention and a safety rail which extends through the rail location section, wherein the cross-sectional shape of the rail has, in use, in at least one of a vertical and horizontal direction, a dimension corresponding to the minimum diameter or dimension of the bore in the corresponding direction.

Accordingly the present invention teaches that as considered in a longitudinal sectional view in a plane containing the longitudinal, major axis of the bore of a solid type rail location section and the longitudinal axis of the elongate section, at least one of the two edges defining the bore in said cross-section is non-rectilinear and lies closer to the longitudinal axis of the bore at a position between the ends of that edge than at end positions of said edge.

Said non-rectilinear edge may comprise two rectilinear edge sections which each extend inclined to said axis of the bore or, for example, said edge may be of a curved shape. If of a curved shape, the edge may be of a convex shape such that the distance of the edge from the axis of the bore increases at a progressively increasing rate from a position between the ends of the bore, preferably from a position mid-way between the ends of the bore, to each end position.

One edge of the bore, as considered in said longitudinal cross-section, may be of a shape different from that of the other edge. For example, one edge may be rectilinear. More typically, however, the two edges of a bore may be of the same shape.

Particularly if each edge is of the same shape, the rail location section will have the advantage that, when constructing a safety rail assembly, a safety rail may extend through the bore in a direction which is slightly inclined, e.g. plus or minus 100, or even plus or minus 150 relative to the major axis of the bore. Thus any modest difference between the inclination of the major axis of the bore and the inclination of the walkway, ramp or stairway may be accommodated without having to subject the safety rail to undue deformation.

This is a particular advantage in the case of a standard constructed for use with a stairway which typically will have an inclination in the range 350 to 400 or even up to 450 to the horizontal. A standard constructed in accordance within the present invention, with the bore of the or each aperture inclined at, say, 50 or 52'12 to the length of the standard can be used for any stairway inclination within the conventional inclination range. Thus the need to manufacture and maintain stocks of standards with ball sections having apertures at different inclination angles in the range 500 to 55 is avoided. A similar advantage arises in respect of standards for walkways.

In parallel with the feature and advantage discussed in the preceding paragraph, there arises also the advantage of being able more readily to feed a pre-curved safety rail through a rail location section The cross-sectional shape of the bore of a solid type rail location section, in a plane perpendicular to the longitudinal, major axis of the bore, typically may be circular at all positions along the length of the bore. That shape is particularly suitable for providing effective support and location for a rail of the conventional circular cross-sectional shape.

Alternatively, however, the bore may be of a shape which varies at cross-sectional positions along the length of said major axis. Thus, for example, the bore may be of an oval or elliptical shape at the ends thereof and of a circular shape mid-way between the ends.

The cross-sectional shape of the bore at the ends may have a width, being the dimension of the bore in a generally horizontal direction when in use with the standard extending vertically, which corresponds substantially with the width of the generally horizontally extending rail thereby to restrain the rail against movement in a horizontal direction relative to the standard, in a direction perpendicular to the major axis of the bore. However, between the ends of the bore the dimension in said width direction may be greater thereby to provide a small space into which the horizontally extending rail may locally deform in the event that it is wished to more readily rake the safety rail or to achieve a greater degree of rake than otherwise would be possible.

The outer surface of the rail location section may be part spherical, the rail location section then being substantially in the form of a solid or hollow ball.

Other shapes, such as for example a cylindrical outer profile, may be employed.

The elongate section may be tubular or may be solid.

The rail location section may be formed for example be casting, moulding or machining. The aperture of the rail location section may be formed during casting or moulding of that component, or may be formed subsequently by machining or forging.

The standard may be of a conventional type comprising two elongate sections between which a rail location section is interposed, and with one of the elongated sections having a second rail location section attached to the other end thereof. The other of the two elongate sections may have attached thereto a mounting plate, or, in use, may be secured within a socket formation of a mounting plate or like component for location relative to a support surface.

Suitable materials for forming the rail location section include cast iron, steel, aluminium and plastics such as glass fibre reinforced plastics and suitable materials for the elongate section(s) of the standard, or for the rail of a safety rail assembly include steel, aluminium and glass fibre reinforced plastics.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which:-Figure 1 is a perspective view of a safety rail assembly in accordance with the present invention; Figures 2 & 3 are respectively side and front views of a standard in accordance with the present invention; Figures 4 & 5 are respectively longitudinal cross-sectional and end views of a rail location section in accordance with the present invention, and Figures 6, 7 & 8 show alternative cross-sectional shapes for the bore of a rail location section.

The safety rail assembly 10 shown in Figure 1 comprises a plurality of standards 11 which each support an upper horizontal safety rail 12 and an intermediately positioned safety rail 13. The standards are each secured in conventional manner in the socket of a mounting plate 14 which is adapted to be bolted to a support surface such as that of a roof or walkway.

Each standard 11 comprises two solid rail location sections 15,16 each having a through-bore 17 through which the respective safety rail 12, 13 extends in the assembly of Figure 1.

Each rail location section 15, 16 has a part-spherical outer profile 18, the rail location section thus appropriately being referred to as a ball section. One ball section 15 is welded to the upper end of a tubular post section 19 and the other ball section 16 is welded between the other end of the post section 19 and an end of the other tubular post section 20 of a standard 11. The post sections 19, 20 in this embodiment each have a diameter whichis approximately 82% of the axial length of each through-bore.

The bore 17 of each bail section is of a circular cross-sectional shape, and the axial length of the bore is approximately 15% greater than the minimum diameter of the bore.

As considered in the length of the major, longitudinal axis 21 of the bore, the diameter of the bore increases progressively, by approximately 15%, from a position 22 mid-way between the ends of the bore to each end 23, 24. Thus, as viewed in cross-section in Figure 4, the bore 17 is defined by two edges 25, 26 which each lie closest to the axis 21 at the position 22 mid-way between the ends of the bore, and which increase in distance away from that axis at a progressively increasing rate from the mid-position 22 to each of the ends 23, 24. In this embodiment the edges 25, 26 are of a smooth convex shape.

In consequence of the curvature of the edges 25. 26, when the welded assembly of ball sections 15, 16 and vertical post sections 19, 20 is suspended vertically from either end for the purpose of hot dip galvanising, the curvature of each bore ensures that any excess zinc deposit tends naturally to drain away from the bore. Accordingly the risk of the minimum diameter of the bore being unduly reduced by the presence of excess zinc deposits is minimised and, correspondingly, the risk of difficulty of feeding a standard sized horizontal rail through the bore is substantially reduced or avoided, A further benefit of the aforedescribed shape of the bore 17 is that it allows the safety rail to be raked, for example at angle of up to 10 , possibly more, relative to the horizontal, with the standard 11 extending vertically.

Accordingly there is avoided the need to provide specially fabricated standards in which the axis of the or each ball section bore is off-set from a direction perpendicular to the length of the standard. Additionally it is possible more readily to feed a pre-bent safety rail through the ball section.

Figures 6 and 7 show examples of other cross-sections of the bore 17a, 17b which result in the aforedescribed advantages of inherent tendency for draining of surface treatment from the bore and ease of raking a safety rail.

However, if there is no requirement for raking and if the ball section is conveniently to be suspended in a pre-determined orientation during surface treatment, a cross-section 1 7c such as that shown in Figure 8 may be employed.

Although the invention has been described in conjunction with the drawings with particular reference to constructing a safety rail assembly for a horizontal walkway, it will be understood that, as described earlier in the specification, the ball sections 15, 16 may be orientated such that, in use, each has a major axis inclined to the horizontal, for example in the range 35 to 40 which is the typical inclination range for a stairway.

Furthermore although there is particular reference above to a galvanised surface treatment it is to be understood that standard may be subject to other types of surface treatment, whether protective or solely decorative. Similarly, it is not essential that the standard is constructed by conventional welding of the ball sections to the vertical tube sections 19, 20. Other techniques such as friction welding may be employed KKL3TDE6

Claims

Claims.

1. A standard for a safety rail, said standard comprising an elongate section and a rail location section having through-bore, the cross-section of said through-bore being greater at at least one end thereof than at a position between the ends of the through-bore or at the other end of the through-bore.

2. A standard according to claim 1 wherein said rail location section is a solid formation.

3. A standard according to claim 2 wherein the cross-section of the bore is smaller at a position between the ends of the bore than at one or each end of the bore.

4. A standard according to claim 3 wherein the bore increases in cross-section from a position between the ends of the bore to each end of the bore.

5. A standard according to claim 3 or claim 4 wherein the said cross-section increases from a position which is mid-way between the.ends of the bore.

6. A standard according to any one of claims 2 to 5 wherein the minimum cross-sectional dimension of the through-bore, at at least one end thereof, is in the range 105% to 140% of the minimum cross-sectional dimension at a position between the ends of the bore.

7. A standard according to claim 6 wherein said range is between 110% and 125%.

8. A standard according to any one of claims 2 to 7 wherein, as considered in a longitudinal cross-sectional plane containing the longitudinal, major axis of the bore and a longitudinal axis of the elongate section, at least one of the two edges defining the bore in said cross-section is non-rectilinear and lies closer to the longitudinal axis of the bore at a position between the ends of that edge than at end positions of said edge.

9. A standard according to claim 8 wherein said non-rectilinear edge comprises two rectilinear edge sections which each extend inclined to said axis of the bore.

10. A standard according to claim 8 wherein said non-rectilinear edge is of a curved shape.

11. A standard according to claim 10 wherein said edge is of a convex shape such that the distance of the edge from the axis of the bore increases at a progressively increasing rate from a position between the ends of the bore.

12. A standard according to any one of claims 8 to 11 wherein one edge of the bore, as considered in said longitudinal cross-sectional plane, is of a shape different from that of the other edge.

13. A standard according to any one of claims 8 to 11 wherein the two edges of the bore are of the same shape.

14. A standard according to any one of claims 2 to 13 wherein the cross-sectional shape of the bore, in a plane perpendicular to the longitudinal, major axis of the bore, is circular at all positions along the length of the bore.

15. A standard according to any one of the preceding claims wherein the bore of the rail location section is inclined relative to the length of the standard by at least 30 . k

16. A standard according to claim 15 wherein said angle is at least 50 .

17. A standard according to any one of the preceding claims wherein the rail location section is a hollow formation.

18. A standard according to claim 1 and substantially as hereinbefore described.

19. A safety rail assembly comprising a standard in accordance with any one of the preceding claims and a safety rail which extends through the rail location section, wherein the cross-sectional shape of the rail has, in use, in at least one of a vertical and horizontal direction, a dimension corresponding to the minimum diameter or dimension of the bore in the corresponding direction.

20. An assembly according to claim 19 wherein the cross-sectional shape of the bore at the ends thereof has a width, being the dimension of the bore in a generally horizontal direction when in use with a standard extending vertically, which corresponds substantially with the width of the generally horizontally extending rail thereby to restrain the rail against movement in a horizontal direction relative to the standard, in a direction perpendicular to the major axis of the bore.

21. A safety rail assembly according to claim 20 wherein between ends of the bore the dimension in said width direction is greater thereby to provide a small space into which a horizontally extending rail may locally deform.

22. A safety rail assembly comprising a standard in accordanc? with any one of claims 1 to 18 and a safety rail which extends through the rail location section.

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