AU699109B2

AU699109B2 - Ladder supporter

Info

Publication number: AU699109B2
Application number: AU62055/96A
Authority: AU
Inventors: William Urquhart
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-08-17
Filing date: 1996-08-13
Publication date: 1998-11-19
Anticipated expiration: 2016-08-13
Also published as: AU6205596A

Description

P/00/01il Regulation 3,2

AUSTRALIA

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ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "LADDER SUPPORTER"

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The following statement is a full description of this invention, including the best method of performing it known to me: 2 THIS INVENTION relates to a stabilizer for ladders.

Throughout the specification, the term ladders will be used to include movable steps and the like.

Safe use of ladders is of major significance whether in the workplace or the home. Occupational safety legislation puts considerable onus on both employers and employees to ensure that ladders are used safely.

While ladder designs have been improved, eg., with the design of non-skid feet, there is still a problem of securing the ends ofI ladders to structures, eg., roof fascias or gutters, shipping containers or the like before the user steps onto the ladder. It is not safe practice to require a workman to climb a ladder so that the upper end •ec of the ladder can then be secured, eg, to a shipping container.

Additionally, there is danger to the workman after the upper end of 15 the ladder has been released from the shipping container or the like.

*99* *9l It is an object of the present invention to provide a o. stabilizer which can be fitted to a ladder to enable it to be releasably os 9 restrained to a supporting structure.

It is a preferred object of the present invention to provide 9 o 0 such a stabilizer which can be fitted at a number of locations along the ladder.

It is a further preferred object of the present invention to provide such a stabilizer which has hook means which may be 1L~~ iiiiiYiTriL-~EZ~ I I oC o 4c *444 04 40 .4.4 4r 4 4 k i 0.

0I* tpr L i j configured to suit engagement with particular structures.

It is a still further preferred object of the present invention to provide such a stabilizer which is easily fitted and used, and which can be easily and inexpensively manufactured.

Other preferred objects of the present invention will become apparent from the following description.

In a broad aspect, the present invention resides in a stabilizer for ladders including: a pair of plates adapted to receive a ladder stile therebetween; spacer means interconnecting the plates and adapted to bear on an adjacent face of the stile; hook means at or ad!acent one end of the plates to releasably engage a structure; and 15 aligned slot means in the plate to receive a rung of the ladder; so arranged that: when the hook means are engaged with the structure and the ladder is pulled downwardly and/or outwardly relative to the structure, the rung is caused to engage one end of the slots, and the 20 spacer means are caused to bear on the one face of the stile, to enable the stabilizer to releasably secure the ladder to the structure.

The plates may be formed from sheet steel, aluminium, reinforced plastics or other suitable material and preferably the plates

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tr A tp 4 are spaced to provide at least a small running clearance between the stile of the ladder and the plates.

Preferably, the spacer means includes two bars, rods or the like adjacent one side of the plates and are adapted to preferably bear against the face of the stile spaced from the structure.

Preferably, each hook means has a tongue relatively offset relative to the plates, and the side edges of the tongues may be convergent towards the tips of the hooks to provide a wedging engagement with the structure. Serrations may be provided along one or both side edges of the hooks to increase the releasable locking engagement of the hooks of the tongue with the structure.

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SPreferably, the slot means are elongate and extend t CCsubstantially parallel to the longitudinal axis of the plates, and L aperture means, open to one side of the plate enable the rungs of the ladder to be selectively engaged in the slot means.

Preferably, releasable fingers or latch means selectively allow engagement of the rungs in the slots.

To enable the invention to be fully understood, a preferred embodiment will now be described with reference to the accompanying drawings in which: FIG 1 is a perspective view showing a pair of the stabilizers secured to a ladder; FIG 2 is a side elevational view of one of the stabilizers; i ,i FIG 3 is a front elevational view of the stabilizer of FIG 2; and a Cr C C r CC C a It

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1 FIGS 4 and 5 show the stabilizers releasably securing the ladder to a twist-lock socket on a shipping container.

Referring to FIG 1, a pair of stabilizers 10 are fitted to respective stiles 101, 102 of a ladder 100 to secure the ladder to a structure, eg., a shipping container 200.

Stiles 101, 102 of the ladder 100 are interconnected by a plurality of spaced rungs 103.

10 Referring to FIGS 2 and 3, each stabilizer 10 has a pair of side plates 11, 12 of sheet steel or aluminium (or moulded from, eg., glass fibre-reinforced plastics). The plates 11, 12 are substantially parallel and are spaced to provide at least a small running clearance between the inner faces of the plates 11, 12 and the ladder stile 101, 102 to which the stabilizer 10 is fitted.

The plates 11, 12 are interconnected by spacer assemblies 14, each having a spacer tube 15 is mounted on the shank of a stud 16, extending between the plates 11, 12, each stud 16 being secured by a wing nut 17 or other suitable fastener. Where the disassembly of the stabilizer 10 is not required, the plates 11, 12 could be fixed, eg., by welding to the ends of the spacer tube 15.

An elongate aligned slot 18 (having a longitudinal axis substantially parallel to, but offset from, the longitudinal axis of the iC i 1' i i A~b t i ij LIF--LI--~ P- i. t00r 0 4 C6 C c Sf 545* 6 plates 11, 12) is provided in each plate and has an abutment face 19 at its lower end.

An aperture 20 is open to one face of the plates 11, 12 to enable a ladder rung 103 to be engaged in the slots 18, the entry or release of the rung 103 from the slots 18 being controlled by a pair of spring-loaded fingers 21 which normally close the apertures A hook assembly 22 is provided at the upper end of each plate 11, 12 and has a downwardly-directed tongue 23, offset from the plates 11, 12 with convergent side edges 24, 25 to co-operate 10 with the structure 200 to form a wedging engagement therewith.

The operation of the stabilizer 10 will now be described with reference to FIG 1, where a pair of the stabilizers 10 are used to releasably secure the ladder 100 to a top side or end beam 201 on a shipping container 200.

s15 When the workman has established which rung 103 of the ladder 100 will be just below the beam 201, he swings the fingers 21 inwardly (as shown in the direction of the arrow in FIG 2) to enable the stabilizer 10 to be slipped onto the stile 101, and the appropriate rung 103 to enter the slots 18 in the two plates 11, 12.

The spacer tubes 15 bear on the face of the stile 101 spaced from the beam 201, on which the other face of the stile will rest. A second stabilizer 10 is fitted to stile 102.

The hook assemblies 22 are engaged over the beam 201 j i i i I i 1 i; ii i i n"" tr; i+ i I ~~~""sasula~ AF 7 1/ and the ladder 100 is then pulled downwardly and/or outwardly until the rung 103 engages the abutment faces 19 at the lower ends of the slots 18. The foot of the ladder can then be rested on the ground or supporting surface, eg., the deck of the ship.

The stabilizers 10 will secure the ladder 100 to the shipping container 200 and will prevent the top end of the ladder 100 swinging outwardly or sliding to one side, and will prevent the foot of the ladder 100 from slipping away from the container 200.

To release the ladder 100 from the shipping container Ez"* 10 200, the workman simply pushes the ladder 100 upwardly until the 'tt, 0hooks 22 are released from the beam 201, and then can swing the o'upper end of the ladder 100 outwardly to release it from the shipping container 200.

t In the embodiments shown in FIGS 4 and 5, the hook assemblies 22 have their tongues 23 engaged in a slot 202 of a twist- S lock socket 203 of the top corner of the shipping container 200.

o The spacing of the plates 11, 12 is designed so that the ~external width of the tongues 23 does not exceed the internal width of the slot 202 of the twist-lock socket 203; while the tapered edges 24, 25 of the tongues 23 ensure wedging engagement against the side edges of the slot 202 when engaged in the manner shown in FIG 4.

The shape of the hook assemblies 22 and, eg., the i i'

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0051 11 OM M 8 provision of serrated edges on the tongues 23, can be varied to suit the particular intended application for the stabilizers 10. For example, where the stabilizers 10 are to be engaged with pipework, eg., on scaffolding, the inner edges 25 of the tongues 23 can have a curved profile in side view.

While the embodiment illustrated is shown interconnected by a pair of spacer tubes 15, it will be readily apparent to the skilled addressee that they could be interconnected by one or more straps or webs; and the plates and strap(s) or web(s) could be cast or moulded as an integral unit.

The provision of the spacer tubes 15, as illustrated, ¢°r enables spacer tubes having a range of lengths to be provided to enable spacing between the plates 11, 12 to be easily adjusted to suit ladder stiles 101, 102 having a range of thicknesses.

Various changes and modifications may be made to the Setembodiments described and illustrated without departing from the present invention.

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Claims

1. A stabilizer for ladders including: a pair of plates adapted to receive a ladder stile therebetween; spacer means interconnecting the plates and adapted to bear on an adjacent face of the stile; hook means at or adjacent one end of the plates to releasably engage a structure; and aligned slot means in the plate to receive a rung of the ladder; so arranged that: when the hook means are engaged with the structure and the ladder is pulled downwardly and/or outwardly relative to the structure, the rung is caused to engage one end of the slots, and the spacer means are caused to bear on the one face of the stile, to 15 enable the stabilizer to releasably secure the ladder to the structure.

2. A stabilizer as claimed in Claim 1 wherein: the plates are formed from sheet steel, aluminium, reinforced plastics or other suitable material, and the plates are spaced to provide at least a small running clearance between the stile of the ladder and the plates.

3. A stabilizer as claimed in Claim 2 wherein: preferably, the spacer means includes at least two bars, straps or the like, an integral web, adjacent one side of the plates, 1~1 (S~t Sitt S t C (t CC S CSC '4 S SC SCt: adapted to bear against the i'ace of the stile spaced from the structure.

4. A stabilizer as claimed in any one of Claims 1 to 3 wherein: each hook means has a tongue relatively offset relative to the plates, and the side edges of the tongues are optionally convergent towards the tips of the hooks to provide a wedging engagement with the structure.

A stabilizer as claimed in Claim 1 wherein: serrations are provided along one or both side edges of the hooks to increase the releasable locking engagement of the hooks of the tongue with the structure.

6. A stabilizer as claimed in any one of Claims 1 to wherein: the slot means are elongate and extend substantially parallel to the longitudinal axis of the plates; and aperture means, open to one side of the plates, enable the rugs of a ladder to be selectively engaged in the slot means.

7. A stabilizer as claimed in Claim 6 wherein: releasable fingers or latch means selectively allow engagement of the rungs in the slots.

8. A stabilizer for a ladder substantially as hereinbefore described. -_YICC*Lli-~ r 1 I

9. A ladder fitted with at least one stabilizer substantially as hereinbefore described. DATED this thirteenth day of August 1 996. WiILLIAM LUROLJHART By his Patent Attorneys FISHER ADAMS KFLLY T. $o ai: i~ r:I If 12 ABSTRACT A stabilizer (10) for a ladder (100) has a pair of side plates (11, 12) spaced to receive a stile (101, 102) therebetween, with spacer tubes (15) bearing on the stiles (101, 102). The rungs 103 of the ladder (100) are selectively engaged in slots (18) in the plates (11, 12) and the hook assemblies (22) have tongues (23) arranged to engage the structure (200) against which the ladder (100) is placed. When the ladder (100) is pulled downwardly and/or outwardly, the stabilizer (10) releasably restrains the ladder (100) to the structure (200). t t I 1 1 1.