GB2447420A

GB2447420A - Safety gates for access equipment

Info

Publication number: GB2447420A
Application number: GB0704835A
Authority: GB
Inventors: Liam Clear
Original assignee: Safestand Ltd
Current assignee: Safestand Ltd
Priority date: 2007-03-13
Filing date: 2007-03-13
Publication date: 2008-09-17
Also published as: GB0704835D0; WO2008110812A1

Abstract

A safety gate assembly 26 comprises a mounting 28 attachable to scaffolding or an edge protection barrier 24 for builders' trestles. The mounting hingedly supports a gate leaf 30 The safety gate assembly further comprises a keeper 32 comprising a stop 48 which engages the gate leaf in a closed position and prevents the gate leaf from opening in response to forces acting in an opening direction. The mounting 28 supports the gate leaf 30 so as to allow it to be lifted clear the stop and be opened.

Description

SAFETY GATES FOR ACCESS EQUIIPMENT

Field of the Invention

This invention concerns safety gates for access equipment such as scaffolding and builders' trestles. Such safety gates may form part of an edge protection barrier, openable to allow workers to pass through, but normally being closed to prevent accidental falls from height.

Invention Background

It is commonplace to use ladders to allow workers to climb onto or descend from raised working platforms supported by scaffolding or builders' trestles. In many countries it is now mandatory for such raised platforms to be provided with edge protection barriers to reduce the risk of accidental falls. The area where the workers step between the ladder and the platform poses particular problems. Either a gap must be left in the edge protection barrier, or the workers have to climb over or through the barrier. A permanent gap presents a permanent fall hazard. Making workers climb over or through the barrier also presents a risk of falling or other injury, particularly when the workers concerned are carrying tools or building materials. It is known to use unfastenable / refastenable safety chains or an upwardly pivotable length of scaffolding tube to close the gap when no-one is using the ladder. However these measures may not provide effective fall protection even when properly in position. They are difficult to operate particularly with your hands full andlor occupied with grasping the ladder. Often, they will not be properly refastened after use.

These problems are addressed to some extent by GB2367088, which in one embodiment provides a safety gate pivotally mounted to a hinge structure in which the pivot axis lies at an angle to the vertical. The centre of mass of the gate is arranged to be at its lowest position when the gate is closed, thereby ensuring that the gate falls (is biassed) shut. A lower end of the hinge structure is provided with a concave upper surface which mates with a tubular part of the gate. This holds the gate in the closed position, but the gate may still be opened by sideways pressure pivoting it inwardly of the platform. This can cause the gate to open unexpectedly, with potential for accidents and alarm. Such pressure can be applied accidentally by persons either on the ladder or on the platform. The gate is prevented from swinging outwardly of the platform by a projection opposite to and extending away from the hinge structure, and which abuts an adjacent scaffolding pole when the gate is closed.

There is a need for a gate which is more positively retained in the closed position and so is S less likely to be opened accidentally, and yet which can still be opened easily by workers when their hands are full.

Summary of the Invention

The invention provides a safety gate assembly comprising a mounting attachable to scaffolding or an edge protection barrier for builders' trestles, the mounting hingedly supporting a gate leaf, the safety gate assembly further comprising a keeper comprising a stop which engages the gate leaf in a closed position and prevents the gate leaf from opening in response to forces acting in an opening direction, the mounting supporting the gate leaf so as to allow the gate leaf to be lifted clear the stop and be opened. This provides a simple, robust, positively acting locking arrangement for the gate leaf; which substantially eliminates the danger of the gate accidentally being pushed open. At the same time the gate is easily opened when desired, even "no-handed". For example a foot, knee, elbow, shoulder, etc., or an object being carried, can be engaged beneath the gate leaf to lift it clear of the stop and then push it open away from the keeper.

The gate leaf may comprise an open framework or mesh, which is easy and economical to fabricate, affords adequate fall protection and also provides additional purchase points for the lifting movement described above.

The keeper may comprise a further stop co-operable with a part of the gate leaf and whose height exceeds the lifting movement of that part. In this way the gate is prevented from moving past the keeper, for example outwardly of the working platform. Equally, by reversing the positions of the stop and further stop, the gate leaf can be constrained to open to whichever side of the keeper is desired. In its closed position, preferably the gate leaf rests snugly between the stop and further stop, so that there is little free play for movement of the gate leaf along the opening/closing direction. Preferably however there should be sufficient clearance between the gate leaf and stops to allow the gate leaf to drop between the stops easily on closing.

The stop and further stop are conveniently formed by opposed sides of an upwardly open S channel. The stop may comprise a lead-in ramp so that the gate leaf is automatically lifted over it on closing.

As a simple and effective means to allow the lifting movement of the gate leat the attachment between the mounting and the scaffolding or edge protection barrier, or the gate leaf binge, may provide sufficient play.

The keeper may comprise a projecting arm against which a ladder can be rested. This necessarily positions the ladder close to the gate opening, in an orientation such that workers can easily step sideways between the ladder and an adjacent working platform, through the Is gate assembly. Preferably the arm lies above the level of the working platform so that overturning moments caused by workers climbing near the top of the ladder are reduced or eliminated.

The keeper and/or the mounting may be engageable over or within the top of an upright of the scaffolding or trestles. Alternatively or as well, they may be fixed to such an upright by releasable clamps.

A pair of the stops may be provided, one to either side of the keeper, so that the keeper may co-operate with gate leaves hung to either side of it.

The gate leaf may be biassed towards the closed position, for example by resilient means such as a spring, or by rising butt or skewed axis hinges.

Illustrative embodiments of the invention are described below with reference to the drawings.

Brief Description of the Drawings

Figure 1 shows a gate assembly embodying the invention, fitted to a guard rail for a run of builders' trestles; Figure 2 is a more detailed view of the keeper shown in Figure 1, detached from the guard rail, and Figure 3 is a more detailed view of the gate mounting shown in Figure 1, detached from the guard rail.

Detailed Description

As shown in Figure 1, a run of builders' trestles 10 supports a raised working platform 12 formed from scaffolding boards or staging. Further scaffolding boards are used as toe boards 14 at the edge of the platform 12. The trestles 10 include upright supports 16, 16a, 16b that extend above the level of the platform 12. Such trestles are further described in UK Patent specification GB2378978 for example. Upper and lower horizontal rails 18 are fixed is between adjacent uprights 16, 16a, 16b to form an edge protection barrier 24. Transverse pins 20 fixed to the ends of the rails 18 are inserted into pockets 22 attached at suitable intervals along the lengths of the uprights 16, 1 6a, 1 6b, to fix the rails 18 to the uprights.

The rails may be telescopic, to adjust to different trestle spacings. A safety gate assembly 26 is fitted to a gap in the edge protection barrier 24 left between an adjacent pair of the uprights I 6a, 1 6b. The safety gate assembly may thus replace a pair of the rails 18. The assembly comprises a mounting 28 to which a gate leaf 30 is hingedly attached, and a keeper 32. The mounting is fitted to the upper end of the upright 16a, and the keeper is fitted to the upper end of the upright 26b, for co-operation with a downwardly directed edge portion 34 of the gate leaf, as further described below. Workers may access the platform 12 through the open gate leaf; from an adjacent ladder (not shown).

As best shown in Figure 2, the keeper 32 comprises a framework made from square sectioned steel tubing. The framework comprises a vertical arm 36 having a crosspiece 38 welded to its lower end, to form an inverted T' shape. The upper end of the arm 36 has a horizontal plate 40 welded to it. A cylindrical spigot 42 depends from the plate 40, parallel to the vertical arm 36. The spigot 42 is a snug sliding fit in the hollow interior of the trestle uprights. The spigot may therefore be inserted into the upper end of trestle upright 1 6b until the plate 40 contacts the upper end face of the upright I 6b. In this position (shown in Figure 1), the vertical ann lies parallel to and against the outer face of the trestle upright 1 6b. The keeper 32 is thus suspended from the upper end of the trestle upright 1 6b. To further steady the keeper 32 and help to prevent it from rotating around the axis of trestle upright 16b, an opposed pair of gusset plates 44 project from the vertical arm below the spigot 42, so as to engage snugly one on either side of the upright 16b in use.

On the side of the crosspiece 38 that is directed towards the working platform in use (i.e. on the same side as the spigot 42 and the projecting ends of the gusset plates 44), an upwardly open channel member 46a is welded, with its axis parallel to the crosspiece 38. The channel member 46a lies at substantially the same height as the gate leaf edge portion 34 in use. One side wall 48 of the channel 46a forms a stop which selectively prevents the gate leaf 30 from swinging inwardly over the platform 12, and the other side wall 50 of the channel 46a forms a further stop which prevents the gate leaf 30 from opening outwardly of theplatforml2.

From the position shown in Figure 1 in which the gate leaf 30 is slightly ajar, the side of the gate leaf opposite to the mounting 28 is lifted to allow the edge portion 34 to clear the top of the stop 48. For this purpose, the mounting 28 can rock slightly on the trestle upright I 6a, as further described below. The edge portion can then be allowed to drop so as to be held in the channel portion 46a, between the stop 48 and further stop 50. As the channel side walls forming these stops are substantially vertical and securely embrace the gate leaf edge portion 34 in this position, the gate leaf 30 is held securely against opening movement either inwardly or outwardly of the platform 12, under the influence of transversely directed forces.

The side wall 50 is preferably made higher than the side wall 48, such that the further stop extends above the range of lifting movement of the gate leaf edge portion 34. Hence the gate leaf is completely prevented from opening outwardly of the platform 12. To open the gate leaf, the edge portion 34 must be positively lifted over the stop 48 again. This is easily to do deliberately, but difficult to do accidentally. The gate leaf comprises a frame welded from steel tube. The necessary lifting for opening and closing can therefore be done by a worker even with their hands full, by engaging a foot, knee, elbow, shoulder etc., or an item being carried, beneath any suitable horizontal portion of the gate leaf frame, towards the keeper side.

Optionally, the keeper may comprise a generally horizontal arm 52 against which a ladder may be leant and tied securely, for accessing the platform 12. With the keeper in position on the upright 1 6b as shown in Figure 1, the ladder (not shown) then extends diagonally partially across the opening in the edge protection barrier 24 occupied by the safety gate assembly 26. With the gate leaf 30 open, workers can easily step sideways between the ladder and platform 12. The arm 52 supports the ladder at a position well above the platform 12, so that forces imposed on the ladder by workmen using it do not generate overturning moments. A rectangular plate 54 forms an end stop for the ladder at the free end of the arm 52. The gusset plates 44 serve to reinforce the welded connection between the horizontal and vertical arms 52, 36.

A channel member 46b may be provided at the opposite end of the crosspiece 38, symmetrical to channel member 46a, to provide a stop and further stop for a gate positioned to the other side of the keeper 32. The illustrated keeper is therefore both left and right handed.

Figure 3 shows the gate mounting 28 in more detail. It comprises a channel-shaped body 56 arranged with its axis substantially vertical. Upper and lower arms 58, 60 extend outwardly from the base of the channel towards the gate leaf 30 (only partly shown in Figure 3). An axle 62 is mounted between the ends of the arms. A bearing sleeve 64 is rotatably mounted on the axle 62 and the gate leaf 30 is hung from the bearing sleeve by a web 66. The upper arm 58 is longer than the lower arm 60 so that the axis of the bearing sleeve 64 lies at an angle to the vertical. The web 66 is trapezoidal in shape, so that in the illustrated closed position, the adjacent stile 68 of the gate leaf 30 lies substantially parallel to the axis of the body 56. When the gate leaf 30 is opened, it rotates on the bearing sleeve 64 and therefore lifts up as it opens. Conversely, the gate will fall from an open position towards the closed position. The skewed axis of the bearing sleeve 64 and axle 62 therefore biases the gate leaf towards the closed position.

The upper end of the channel through the body 56 is closed by a top wall 70, from which depends a pin 72. The lower end of the channel is partly closed by a bottom wall 74. When the mounting 28 is fitted to an upright such as 1 6a, the pin 72 is a loose sliding fit in the hollow upper end of the upright. The weight of the gate leaf 30 exerts a turning moment on the mounting 28 that causes the free edge 76 of the bottom wall 74 to be braced against the upright 16a. The loose fit of the pin 72 allows the distal end of the gate leaf to be lifted slightly, causing the edge 76 to part company from the upright 16a and the mounting 28 to rock slightly on the pin 72. This lifting movement is enough to allow the gate leaf edge portion 34 to be lifted over the stop 48, as described above. The space above the bottom wall 74 in the body 56 is sufficient to accommodate the uppermost pocket 22 on the gate leaf side of the upright 1 6a. The opposite pocket 22a projects freely from the mouth of the channel-shaped body 56 for connection of a horizontal rail 18.

Similarly, the pockets 22 on the adjacent upright 22b remain unobstructed by the keeper 32.

Although the channel members 46a, 46b are aligied with the upright 1 6b in use and are substantially the same height as the lowermost pockets 22, the channel members are spaced to either side of the upright 1 6b at the ends of the crosspiece 38, leaving sufficient clearance for the pockets 22 and the corresponding rail 18. The upper pockets 22 on the upright 22b remain accessible to either side of the keeper vertical arm 36 and horizontal plate 40.

Numerous variations and modifications of the particularly described embodiment are possible within the scope of the claims. For example, the movement of the gate leaf (either rocking or translational or a combination of both) to allow lifting of the edge portion over the stop can be accommodated at the hinge mechanism, with the mounting firmly fixed to the adjacent edge protection barrier, e.g. such a barrier formed from scaffolding. The gate leaf need not be biassed towards the closed position, or other biasing means such as springs, rising butt hinges or other door or gate closers conventional as such can be used. The keeper may co-operate with differently positioned parts of the leaf frame, which can likewise be lifted over the stop. The stop 48 may be provided with a lead-in ramp or striker plate (78, shown in ghost lines in Figure 2) so that the gate leaf edge portion can be lifted over the stop 48 simply by pulling the gate closed, or allowing it to close with sufficient momentum.

Claims

1. A safety gate assembly comprising a mounting attachable to scaffolding or an edge protection barrier for builders' trestles, the mounting hingedly supporting a gate leaf, the safety gate assembly further comprising a keeper comprising a stop which engages the gate leaf in a closed position and prevents the gate leaf from opening in response to forces acting in an opening direction, the mounting supporting the gate leaf so as to allow the gate leaf to be lifted clear the stop and be opened. I0

2. A safety gate assembly as defined in claim 1, in which the gate leaf comprises an open framework or mesh.

3. A safety gate assembly as defined in claim 1 or 2, in which the keeper comprises a further stop co-operable with a part of the gate leaf and whose height exceeds the lifting movement of that part.

4. A safety gate assembly as defmed in claim 3, in which in its closed position, the gate leaf rests snugly between the stop and further stop.

5. A safety gate assembly as defmed in claim 3 or 4, in which the stop and further stop are formed by opposed sides of an upwardly open channel.

6. A safety gate assembly as defined in any preceding claim, in which the stop comprises a lead-in ramp so that the gate leaf is automatically lifted over the stop on closing.

7. A safety gate assembly as defined in any preceding claim, in which the attachment between the mounting and the scaffolding or edge protection barrier, or the gate leaf hinge, provide sufficient play to allow the lifting movement of the gate leaf.

8. A safety gate assembly as defined in any preceding claim, in which the keeper comprises a projecting arm against which a ladder can be rested.

9. A safety gate assembly as defined in claim 8, in which the projecting arm lies above the level of the working platform

10. A safety gate assembly as defined in any preceding claim, in which the keeper andlor the mounting are engageable over or within the top of an upright of the scaffolding or trestles.

11. A safety gate assembly as defmed in any preceding claim, in which the keeper and/or the mounting are fixed to an upright of the scaffolding or trestles by releasable clamps.

12. A safety gate assembly as defmed in any preceding claim, in which a pair of the stops are provided, one to either side of the keeper, so that the keeper may co-operate with gate leaves hung to either side of it.

13. A safety gate assembly as defmed in any preceding claim, in which the gate leaf is biassed towards the closed position,

14. A safety gate assembly substantially as described with reference to or as shown in the drawings.