GB2254098A

GB2254098A - Ladder safety frame.

Info

Publication number: GB2254098A
Application number: GB9102772A
Authority: GB
Inventors: Ronald Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-02-09
Filing date: 1991-02-09
Publication date: 1992-09-30
Anticipated expiration: 2011-02-09
Also published as: GB2254098B; GB9102772D0

Abstract

A safety frame for a ladder has two hook means (14, 16), each to engage a rung of the ladder and a rigid hoop (12) connected to the hook means and arranged to prevent the user from falling back, e.g. while repairing guttering. The hook means are positively fixed to the rungs by bolts (28) and nuts (29). <IMAGE>

Description

SAFETY FRAME This invention relates to a safety frame, and in particular to a ladder safety frame.

Many persons are fearful of working at height, and are particularly fearful of tasks to be done whilst standing on the rungs of a ladder, holding by one hand only. Some tasks such as fixing guttering, or drilling require both hands to be released from the ladder, whilst others (such as removing brickwork) require in addition heavy tools to be swing with force.

Although it is known for fire escape ladders fixed vertically to the outside wall of a building, to have rigid safety hoops fixed thereto, it has not previously been proposed so far as we are aware to provide a rigid safety hoop as part of a removable safety frame, usable with a removable, non-fixed ladder.

We are also aware that signalmen who are required to work at height, e.g. on telegraph and similar poles, use a "loop", but this is of a flexible material and so the signalman is required to remain pressed against it (to prevent it slipping), i.e. it is a loop forming part of his operating gear, rather than an ancillary safety hoop for occasional use, and being required strictly for emergency use, only rarely.

Thus we now propose a safety frame for use with a ladder having in use vertically spaced rungs, comprising a rigid hoop, a first hook arrangement, a second hook arrangement, said hook arrangements being adapted removably to embrace part of two ladder rungs, the hook arrangements and the hoop being rigidly interconnected.

In a preferred embodiment, the hoop is connected to a pair of hooks forming the upper hook arrangement, and is additionally supported by rigid stays. The hoop can be adjustable in size, to suit-different users, whilst the hooks can be pivotally connected to the hoop to permit storage in a 'lay-flat' condition. The stays can be adjustably connected to the hoop, to permit the hoop attitude or angle to be varied, for instance so that it comfortably fits into the small of the user's back. Usefully, to reduce weight, the safety frame is of tubular aluminium, though in an alternative embodiment the hooks can be formed from a solid sheet of material.

Preferably the safety frame includes a catch for each hook, adapted to hold the hook to a ladder rung, and usefully the catch is pivoted to part of the hook and locked by a butterfly nut.

However the catch can be. pivoted catch spring-biased towards the locking condition wherein it grips around a frame cross-strut and a (lower) ladder rung.

As an additional safety feature, the ladder can have (removably) mounted on its upper end a friction cross-strut, adapted to prevent lateral (sideways) slippage of the ladder, under the more vigorous usage safely available when our safety frame is fitted.

The invention will be further described by way of example with reference to the accompanying schematic drawings, in which: Figure 1 is a side view of a safety frame according to the invention, in use adjacent a building roof; Figure 2 is a perspective view of one embodiment of safety frame according to the invention; Figure 3 is a side view of the safety frame of Figure 2; Figure 4 is a perspective view of the safety frame of Figure 2 fitted on a ladder, on which is also mounted a friction cross-strut; Figure 5 is a perspective view of a plate cut to form an alternative embodiment of the invention, and with a rigid hoop and stays indicated in ghost outline; and Figure 6 is a side view of an alternative embodiment to that of Figure 3, with adjustable components, and suited for lay flat storage.

Figure 7 is of an alternative embodiment of hook to that shown in Figure 2, with the butterfly nut inwards of the frame; Figure 8 is a perspective view of the arrangement of Figure 7; Figure 9 is of a further alternative embodiment of hook, with the bolt located in an elongated slot; Figure 10 is a perspective view of the arrangement of Figure 9; Figure 11 is a perspective view of another embodiment of hook; and Figure 12 is a side view, of an alternative embodiment to that of Figure 6.

User 1 is standing on a rung of ladder 2, and is fitting guttering 3 using tool 4. Guttering 3 is supported in one hand, and tool 4 in the other.

User 1 is supported by a safety frame 10 according to the invention, whilst ladder 2 is located by a friction cross-strut 5 also disclosed in this application, and to which further reference is made below. Such stabiliser or friction cross-strut allows work to be carried out more safely at window opening, i.e.

by strapping a suitable length of timber to the disclosed angle to span the window opening.

The safety frame 10 of Figure 2 includes a rigid hoop 12, a first (upper) hook arrangement comprising spaced hooks 14, and a second (lower) hook arrangement comprising spaced hooks 16. The hoop 12 is connected to the hooks 14, whilst hooks 14 are themselves connected together by cross-piece 20, hooks 16 are connected together by cross-piece 22, and are connected to (upper) hooks 14 by upwardly extending struts 24,26. Cross-piece 20 has cranked sections 21, and cross-piece 22 has cranked sections 23.

In this embodiment the frame is given further rigidity by the use of stays 27, which extend between hoop 12 and cross-piece 22. In an alternative embodiment stays 12 are connected respectively to struts 24,26 respectively.

Each hook 14, 16 has an associated locking bolt 28 and is locked by butterfly nut 29. In the embodiment of Figure 3 the butterfly nut 29 is outwards of the frame; in the embodiment of Figures 7,8 the butterfly nut 29 is inwards of the frame. In the alternative embodiments of Figures 9,10, the locking bolt 28 is pivotally mounted to one arm of the hook 14 and fits within an open ended slot 27 in the other arm of the hook, i.e. the slot 27 is downwardly directed as viewed in Figure 10, pivotally mounted in the inwards hook arm 14a and engagable in the slot 27 in the outwards hook arm 14b.

As seen in Figure 4, a ladder stabiliser in the form of a novel friction cross-strut 5 is held to the uprights 6 of ladder 2 by screws 6 located in tapped holes in connecting parts 7. In this embodiment, cross-strut 5 is of length 3 feet, and of 1.5" x 1.5" angle iron; connecting parts 7 are of hollow box form 2" x 3.5" x 4". If required a beam, e.g. of wood, can be strapped or otherwise affixed to angle cross-strut 5.

In the embodiment of Figure 5, a metal plate 30 has cuts 32,34,36. These are each used to form a single hook, i.e. in use an upper hook 44 and a lower hook 46, vertically space in one embodiment, the plate is of 3/8" thick aluminium. Strengthening tubes 45 are provided. In the alternative embodiment of Figure 11, only two bolts 28 are used, with respective butterfly nuts 29.

In use the hooks 14,16 and 44,46 closely embrace rungs 50 of ladder 52 in this embodiment they are of 1" x 3/8" bar; because the safety frame has upper and lower hook arrangements, the frame is prevented both from pivoting about one or other of the rungs, and from forwards and rearwards transitional movement.

Preferably the hook arrangements fit closely within the uprights 6 of ladder 2, to inhibit sideways movement of the frame relative to ladder 2.

In an alternative but less preferred embodiment, preferably the frame includes a single pivoted catch biassed by a spring towards a locking condition wherein it grips around both lower rung 50 and cross-piece 22, whereby to hinder inadvertent lifting of the safety frame when fitted onto the ladder 2.

Usefully the hoop 12 has a diameter of 22", and is of C-shape, the hoop being "completed" by cross-piece 20, though the hoop can be continuous with a section alongside cross-piece 20, and perhaps connected thereto. In a preferred embodiment the safety frame 10 is of aluminium, with the component parts bolted together, but alternatively can be of a weldable material.

Though the cross-pieces 20,22 can be circular in cross-section, usefully they are made from 2" x 3/8" bar, whilst the hoop 12 is of 1.5" and 3/8" bar and hooks 14,16 are of 1" x 3/8" bar. In an alternative embodiment the safety frame components are of different materials, and of hollow tube.

Thus we have now disclosed a safety frame, which can be easily fitted to a ladder, including an extending ladder, thus if the ladder rests against a fascia board the hoop 12 can be horizontal or at a small angle below the horizontal notwithstanding that the ladder is itself angled to the true vertical. Thus the hoop in use is at an acute included angle to the ladder.

The rigid hoop 12 can be used to hold a tool container, which can be hooked or looped thereover.

In use, the safety frame will give we believe the user the confidence to release both hands from the ladder, e.g. when painting a soffit board at the house eaves.

When the ladder is no longer required, the safety frame can be removed, either before the ladder is lowered to the ground, or afterwards, and stored separately as required, i.e. the convenient storage and (roof-rack) transport shape of the standard ladder is not affected. As indicated in the embodiment of Figure 6, the safety frame can be collapsed to the 'lay-flat' condition, following removal of pin 60, and pivoting of stays 27 about pivot 62. Furthermore, the attitude or inclination angle of hoop 12 in use, i.e. as seen in Figure 1, can be altered by re-positioning pin 60 in another aperture 64. In the alternative embodiment of Figure 12 one or both hoop ends are connected to end pieces 21 of cross-piece 20 by a pair of removable pins 62 whereby the size of the hoop can be adjusted; apertures 64 are in a separate piece 70 affixed in the hoop length.

Although we prefer the hook arrangements to fit partly around adjacent ladder rungs, the vertically extending struts 24,26 can be cranked or otherwise formed so that there are (unused) rungs between those about part of which the hook arrangements grip.

Claims

1. A safety frame for use with a ladder having vertically spaced rungs, the frame comprising upper and lower hook means adapted removably to embrace part of two rungs of the ladder, the hook means being rigidly connected together, a hoop portion connected to at least one of the hook means and arranged to prevent the user from falling off the frame, the hoop being rigid and rigidly connected to the hook means.

2. A frame according to Claim 1, wherein the hoop portion is connected to the upper hook means.

3. A frame according to Claim 1 or 2, wherein the hoop portion is supported by rigid stays.

4. A frame according to any preceding Claim, wherein the hoop portion is of generally "C" shape as seen in plan.

5. A frame according to any preceding Claim, wherein the hoop portion is formed of tubular aluminium.

6. A frame according to any preceding Claim, wherein the hook means comprises a pair of spaced hooks.

7. A frame according to any of Claims 1 to 5, wherein the hook means comprises a single hook.

8. A frame according to any preceding Claim, including lock means to lock a hook means to a rung of the ladder.

9. A frame according to Claim 8, wherein the lock means comprises a catch which is locked by a butterfly nut.

10. A frame according to Claim 8, wherein the lock means is spring biased.

11. A frame according to any preceding Claim, adapted to be collapsed to lay flat condition.

12. A frame according to any preceding Claim, in combination with a ladder.

13. A frame according to Claim 12, wherein a cross-strut is present at the top end of the ladder, the cross-strut being elongate and adapted to abut the wall against which the ladder is placed.

14. A safety frame substantially as described and with reference to the drawings.

15. A method of carrying out a task whilst standing on a ladder, a safety frame according to any of Claims 1 to 11 and 14 being present on the ladder, the operator being held from falling by the hoop portion of the frame.