WO2002006623A1

WO2002006623A1 - Ladder safety device

Info

Publication number: WO2002006623A1
Application number: PCT/IE2001/000091
Authority: WO
Inventors: Joseph Barrett; Daniel Barrett
Original assignee: Joseph Barrett; Daniel Barrett
Priority date: 2000-07-14
Filing date: 2001-07-13
Publication date: 2002-01-24
Also published as: IES20010663A2; AU2001269396A1

Abstract

A ladder safety device comprises stand-off means (20) for bearing against a roof (16) of a building (18) to maintain the ladder out of contact with the building. The stand-off means comprises a pair of substantially rigid arms (122) which diverge away from one side of the ladder so that the separation of the arms at their free ends is substantially greater than the separation of the ladder uprights. A respective X-shaped load spreading member (128) is mounted to the free end of each arm for rotation about two mutually perpendicular axes.

Description

Ladder Safety Device

This invention relates to a safety device for stabilising a ladder when alighting from the ladder to a roof and vice versa.

Conventionally, when one wishes to get on a sloping roof a ladder is positioned with its base on the ground a meter or so from the wall of the building, depending on the height of the building, and the top of the ladder is rested against the eaves or the gutter running along the eaves. However, there is a danger that when a person attempts to move sideways off the ladder onto the roof, or vice versa, the ladder will slip sideways along the eaves or gutter in the opposite direction.

Existing devices to stabilise a ladder against such slipping use elaborate frames or other structures at the base of the ladder. These are cumbersome and hazardous on site.

It is a object of the invention to provide an improved ladder safety device.

According to the present invention there is provided a ladder safety device comprising stand-off means at or near the top of the ladder for bearing against a roof of a building and maintaining the ladder out of contact with the building such that a notional straight line joining the base of the ladder with the part of the stand-off means engaging the roof intersects the line of the roof, wherein the stand-off means comprises a pair of substantially rigid arms at or near the top of the ladder which diverge away from one side of the ladder so that the separation of the arms at their free ends is substantially greater than the separation of the ladder uprights, and wherein a respective load spreading member is mounted to the free end of each arm for rotation about two mutually perpendicular axes.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a front view of a ladder having a safety device according to a first embodiment of the invention placed up against a building for access to a sloping roof;

Fig. 2 is a side view of the ladder of Fig. 1;

Figs. 3A and 3B are side and front views respectively of one of the arm-support brackets of the first embodiment;

Fig. 4 is a cross-section illustrating how the ar - support brackets are clamped to the ladder;

Figs. 5A and 5B are side and plan views respectively of one of the arms of the first embodiment including X- shaped load spreader;

Fig. 6 illustrates a universal coupling between the X- shaped load spreader and the associated arm; Fig. 7 is a front view of a ladder having a safety device according to a second embodiment of the invention; and

Fig. 8 is a cross-section, similar to Fig. 4, illustrating how the arm-support brackets are clamped to the extension members of Fig. 7.

Referring first to Figs. 1 and 2 of the drawings, a ladder 100 comprises a pair of parallel uprights 112 joined by rungs 114 in conventional manner. In order to stabilise the ladder when it is used to gain access to a sloping roof 16 of a building 18, a safety device 20 is rigidly clamped at or near the top of the ladder.

The safety device 20 comprises a pair of substantially rigid arms 122 which diverge symmetrically away from the plane of the ladder 110 on the side facing the building. The separation of the arms 122 at their free ends is substantially greater than the separation of the uprights 112, preferably at least twice the separation of the uprights, such that the free ends of the arms lie laterally beyond the respective edges of the ladder. The angle of divergence of the arms 122 is preferably about 60 degrees.

In use, as seen in Fig. 2, the ladder 110 is positioned such that the only contact with the building 18 is via the arms 122, which bear on the roof 16 and maintain the uprights 112 out of contact with the eaves 24.

Since a notional straight line 26 joining the base of the ladder to the free ends of the arms 122 intersects the line of the roof 16, any tendency of the ladder to slip sideways when a person is moving on or off the ladder is counteracted by the ends of the arms "digging in" to the roof to resist such slippage.

The arms 122 are adjustable in length to accommodate different pitched roofs and, in order to prevent the arms from penetrating the roof from the load applied by the ladder and a person on it, each arm terminates in a respective elongated X-shaped shoe 128 which spreads the load across several roof tiles.

The entire device 220 is preferably manufactured from aluminium, except for friction material 148 (Fig. 5) on the shoes 128.

Referring now additionally to Figs. 3 to 6, each X- shaped load spreader 128 is faced with resilient material 148, and each is mounted to the free end of an arm 122 by a respective joint 150 (Figs. 5 and 6) allowing rotation of the spreader 128 about two mutually perpendicular axes relative to the arm.

Each joint 150 comprises a collar 152 rigidly attached to the free end of the arm 122 and a member 154 passing through and rotatable in the collar about an axis A-A. A lock screw 156 allows the member 154 to be releasably locked against rotation in any desired angular position relative to the collar 152. The lower end of the member 154 has a pin 144 rotatably passing therethrough in a direction perpendicular to the axis A-A. The pin 144 extends between two flanges 146 fixed to the load spreader 128. Thus the load spreader 128 can rotate about an axis B-B relative to the member 154. The joint 150 allows the X-shaped load spreader 128 to adjust to a wide range of roof pitches.

Each arm 122 comprises two parts 122A, 122B telescoped one within the other to permit adjustment of the length of the arm. A particular length is fixed by aligning a selected one of a series holes 130A in the part 22A with a hole 13OB in the part 22B and inserting a pin 131 through both.

The inner end of each arm 122 is rigidly clamped to a respective ladder upright by a respective bracket 132. Each bracket 132 comprises a clamp 134 (Figs. 3 and 4) for embracing the upright 112 on three sides and a cluster of three sockets 136A, 136B and 136C angularly offset from the clamp 134 by different amounts. Each socket 136A-C is in the form of a short length of reinforced hollow pipe for selectively receiving the inner end of the arm part 122B which is rigidly fixed therein by a bolt (not shown) passing through the selected socket 136A-C and part 122B.> The clamps 134 are rigidly fixed to the ladder uprights 112 by a bolt 140 which passes through a hole 160 in one clamp 134 into the interior of a hollow rung 114, where it screw- threadedly engages a barrel nut 142 fixed to and extending within the rung from the other clamp 134.

By the above construction each bracket 134 provides multiple mounting choices for the relevant arm 122 whereby the orientation of the arms 122 relative to the ladder may be varied. In use, a particular pair of sockets 136A, 136B or 136C is chosen for receiving the arms 122 according to the situation at hand. The sockets 136A point up along the roof and the arms 122 are attached to these sockets when a fully extended ladder is only one or two rungs above the eaves-shoot. The sockets 136B correspond to the position where the arms 122 lie in a plane substantially normal to the longitudinal axis of the ladder, and are the sockets which would be used in a normal situation. The sockets 136C angle down to suit a flat roof.

In a second embodiment of the invention, Fig. 7, the ladder 100 includes two preferably telescopic aluminium extension members 200 removably bolted to the tops of the ladder uprights 112 and forming a rung-less upward extension of the ladder. In this case the arms 122 are clamped, via brackets 134 (not shown in Fig. 10), to the top ends of the extension members 200. This arrangement allows the ladder to be used on 3-story buildings. Each member 200 may be constructed as two 4-foot. box aluminium sections, one sliding within the other and lockable at various overall lengths by a pin or bolt passing through selected aligned holes in the two sections in the same manner as the arms 122.

Fig. 8 illustrates how the brackets 134 are clamped to the extension members 200 in a manner that also rigidly ties the top ends of the extension members together in the manner of a rung 202. This is necessary in the absence of actual rungs between the extension members .

A barrel bolt comprising two hollow cylindrical members 204, 206 screw-threaded one within the other is placed between the extension members 200 and the member 204 is rotated on the member 206 until the overall length of the barrel bolt equals the desired spacing of the members 200. Next a continuous bolt 208, screw- threaded at each end, is passed through the barrel bolt 204, 206 and through two holes 210 in the extension members 200 so as to project from either side of the latter. A respective clamp 134 is placed over each end of the bolt 208, the clamp surrounding the respective member 200 on three sides, and the whole assembly is clamped securely in place by nuts 212 screwed onto the opposite ends of the bolt 208 and tightened up against the clamps 134.

The invention is not limited to the embodiments described herein which may be modified or varied without departing from the scope of the invention.

Claims

1. A ladder safety device comprising stand-off means at or near the top of the ladder for bearing against a roof of a building and maintaining the ladder out of contact with the building such that a notional straight line joining the base of the ladder with the part of the stand-off means engaging the roof intersects the line of the roof, wherein the stand-off means comprises a pair of substantially rigid arms at or near the top of the ladder which diverge away from one side of the ladder so that the separation of the arms at their free ends is substantially greater than the separation of the ladder uprights, and wherein a respective load spreading member is mounted to the free end of each arm for rotation about two mutually perpendicular axes.

2. A ladder safety device as claimed in claim 1, wherein each load spreading member is substantially X- shaped.

3. A ladder safety device as claimed in claim 1 or 2 , wherein each arm is adjustable in length.

4. A ladder safety device as claimed in any preceding claim, wherein each arm is removably attached to the ladder.

5. A ladder safety device as claimed in claim 4, wherein each arm is mounted on a respective bracket clamped to the ladder.

6. A ladder safety device as claimed in claim 5, wherein each bracket provides multiple mounting choices for the arm whereby the orientation of the arm relative to the ladder may be varied.

7. A ladder safety device as claimed in claim 5 or 6, wherein the ladder has at least one hollow tubular rung and the brackets are releasably clamped at opposite ends of said rung by fixing means entering the rung from opposite ends.

8. A ladder safety device as claimed in any one of claims 1 to 6, wherein the ladder includes removable extension members attached to the ladder uprights, the extension members forming a rung-less extension of the ladder, the stand-off means being attached to the extension members .