GB2472198A

GB2472198A - Stabilisation device for ladder

Info

Publication number: GB2472198A
Application number: GB0913009A
Authority: GB
Inventors: Joseph Trevor Sidaway
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-07-27
Filing date: 2009-07-27
Publication date: 2011-02-02
Also published as: GB0913009D0

Abstract

A stabilisation or leveling device 20 is suitable for stabilising the standing of a ladder or a four-legged apparatus, such as a stepladder 10 on a support surface. It includes a stabilising member 22 which is secured relative to each of two legs 18, 19 of the apparatus, by a respective link 25, 26. Each link is pivoted relative to the stabilising member and relative to a leg part 18a, 19a of a respective leg so that the links extend downwardly from the respective leg pivots P1, P2 and in opposite lateral directions. A brace (35, fig 2) is provided between the two legs to maintain their distance apart. The stabilisation member may include feet F1, F2 to grip the ground. The stabilization device settles into a rigid structure when weight is applied.

Description

Title: Stabilisation Device Dcription p1 Invention This invention relates to a stabilisation device for stabilising a four legged apparatus such as a step ladder, and for stabilising a lean-to ladder It is well known that using ladders on irregular and/or inclined surface can lead to ladder instability or "wobble". Various proposals have been made for stabilising ladders, Including the use of chocks under the legs of ladders, providing ladder legs with telescoping sections. and even tne use of outriggers which extend sideways from the ladders.

According to a first aspect of the invention i provide a stabilisation device for stabilising the standing of a four-legged apparatus on a support surface, the device including a stabilising member which is secured relative to each of two legs of the apparatus, by a respective link, each link being pivoted relative to the stabilising member and relative to a leg part of a respective leg so that the links extend from the respective leg pivots in opposite directions to the stabilising member at a respective angle to both the leg and the stabilising member, and there being a brace to maintain the distance apart between the two legs.

Utilising the present invention, the weight of the apparatus and, where the anparatus is a ladder, of any person climbing on the apparatus, will tend to pivot the links such that the links will tend to move the legs either apart, where the links extend downwardly from the leg part pivots towards one another, or together where the links extend downwardly from the leg part pivots away from one another. In each case, the brace will maintain the legs a fixed distance apart and so the links, stabilising member leg parts and brace will settle into a rigid structure. Where the support surface is irregular and/or inclined, with the other two legs of the apparatus supported on the support surface, the links will settle in different angles to the leg parts as required by the irregular and/or uneven ground, and the apparatus will be stable.

Particularly where the invention is applied to a step ladder for example, the invention provides a more satisfactory solution to ladder instability than using chocks for example which are not inherently safe, and because the device will automatically pivot to angles where the step ladder is stabilised, there is no need for a user to perform adjustments as with telescopic leg proposals. As there is no need for outriggers, the present invention does not require any, or at least significant additional footprint space in order to use the device.

The leg parts where the links are pivoted, may be integral with the respective legs of the apparatus, and thus the stabilisation device may be provided as an integral part of the apparatus. However it is envisaged that the stabilisation device may be fitted to an existing four-legged apparatus, in which case the leg parts of the stabilisation device may be secured to the respective legs of the apparatus. In each case, the brace may be located above the links, and may be an integral part of the apparatus, for example, a cross strut between the leg of the apparatus. However, the brace may be an additional component which is secured to each of the two legs or leg parts, to maintain the leg distance apart.

The leg parts to which the links are pivoted, may each be in-line with the remainder of the respective leg of the apparatus, especially where the links extend from their pivots to the leg parts downwardly towards one another, or the leg parts to which the links are pivoted may be located outwardly beyond the respective leg of the apparatus, so that the distance between the two pivots between the links and the leg parts, is greater than the distance between the legs of the apparatus. This is especially desirable where the links extend from their pivots to the leg parts away from one another, and has the effect of increasing the base width of the apparatus, which is particularly useful where the apparatus is tall.

The stabilising member may be a solid bar or hollow elongate fabrication, and may include feet which improve grip between the stabilising member and the ground. For example the feet may be of a softer material than the stabilising member, such as natural or synthetic rubber or plastic.

At least one, but preferably both of the links may be provided by a pair of parallel plates which are coupled together at their one ends, either side of the respective leg part, by an axle which passes through the leg part, thus to provide the pivot connection between the link and leg, and similarly the plates may be coupled together at their other ends, either side of the stabilising member, by an axle which passes through the stabilising member, thus to provide the pivot connection between the link and the stabilising member.

However other link/pivoting arrangements are possible, for example, the links may be of one-piece construction which may add to the rigidity of the stabilisation device and allow for pivots to the respective leg part and the stabilising member with a minimum of play.

The invention has particular but not exclusive applicability to an apparatus which is a step ladder.

According to a second aspect of the invention I provide a stabilisation device for stabilising the standing of a ladder on a support surface, the device including a stabilising member which is secured relative to each of two legs of the ladder, by a respective link, each link being pivoted relative to the stabilising member and relative to a leg part of a respective leg so that the links extend from the respective leg pivots in opposite directions to the stabilising member at a respective angle to both the leg part and the stabilising member, and there being a brace to maintain the distance apart between the two legs.

The ladder may be a step ladder having two rear legs between which rungs or steps extend, and two front legs, each hinged to a respective rear leg. The stabilising member of the stabilisation device may be secured to the pair of front legs by the links, but may instead be secured to the pair of rear legs.

However if desired a stabilisation device may be provided for each of the respective front two legs and rear two legs.

However, the invention may usefully be used for a lean-to ladder which includes a pair of legs only with ladder rungs extending between the legs, the links of the stabilisation device being pivoted to respective leg parts of the only two legs of the ladder. Whereas in the case of a step ladder, the engagement of the two legs to which links of the stabilisation device are not pivoted, on the support surface (ground) will be required to give the four-legged structure stability, where the invention is applied to a lean-to two-legged ladder, the engagement of the legs at their upper ends on a wall for example, will give the ladder overall stability.

According to a third aspect of the invention I provide a ladder including or having attached thereto, a stabilisation device according to the first or second aspect of the invention.

Embodiments of the invention will now be described with reference to the accompanying drawings in which:-FIGURE 1 is an illustrative perspective view of a ladder which includes a stabilisation device in accordance with the present invention; FIGURE 2 is a side illustrative view of part of the ladder of figure 1; FIGURE 2a is a side view similar to figure 2 but showing at least two legs of the ladder on an inclined surface; FIGURE 3 is a side view similar to figure 2, but of an alternative embodiment.

Referring to the drawings an apparatus 10 is in the example, a step ladder, which is to be supported on a support surface S being the ground. The step ladder 10 has four legs, namely two rear legs 14, 15 between which rungs or steps 16 extend, and two front legs 18, 19. The legs 14, 15 of the pair of rear legs are hinged to respective legs 18, 19 of the front pair of legs to enable the step ladder 10 to be opened for use, and closed for storage, about an axis A. The step ladder 10 is shown supported on irregular and/or inclined ground S. Because the step ladder 10 is a four-legged apparatus, one of the legs, in the example one of the front legs 18, typically, will not be supported on the irregular and/or inclined ground S when the other three legs 14, 151 19 are so supported.

This can lead to ladder instability. Even though the extent of ground S irregularity and/or inclination may not be such as to cause a general imbalance of the step ladder 101 such instability is at the least disconcerting to a user, and often dangerous as this can lead to a user making sudden movements in response to ladder movements, which can lead to imbalance, or a user falling from the step ladder 10.

In accordance with the invention a stabilisation device 20 is provided. This includes a stabilising member 22 which in this embodiment extends beneath the two front legs 18, lOin the example, and which in use, rests on the ground S or other support surface. In the example, the stabilising member 22 is an elongate metal bar1 which could be hollow or solid and of any cross sectional shape, the stabilising member 22 being slightly longer than the width of the step ladder 10 between the two front legs 18, 19, at least in the embodiment shown in figure 3.

Referring particularly to figures 1 to 3, the stabilisatio.n device 20 further includes a pair of links 25, 26. The links 25, 26 are each pivoted at their one, upper, ends (upper when the step ladder 10 is erected), to a leg part 1 Ba, I 9a of a respective one of the front legs 18, 19, at pivots P1 and P2, and the links 25, 26 each extend downwardly towards one another to further pivot positions P3, P4, where the links 25, 26 are pivoted at their other ends to the stabilising member 22. The distance between the pivot connections P3 and P4 between the links 25, 26 and the stabilising member 22 is thus less than the distance between the pivot connections P1 and P2 between the links 25, 26 and the leg parts 18a, lYa. Thus the links 25, 26 extend from their respective pivots P1, P2 to the front leg parts 18a, 19a, downwardly towards one another, at an angle to both the respective leg 18, 19 and the stabilising member 22.

In this example, the links 25, 26 each include a pair of parallel plates, with one plate being located at either side of the respective leg part 18a, 19a, and the stabilising member 22, with there being a first axle 30 provided by a pivot pin which extends between the plates, through the respective leg part 18a, 19a to provide the pivot connection P1 to the respective leg parts iSa, 19a, and a second axle 31 again provided by a pivot pin which extends between the plates, through the stabilising member 22 to provide the pivot connection P2 to the stabilising member 22.

There is provided a brace 35 to maintain the distance apart of the front legs 18, 19 when the stabilising device 20 is in use, the brace 35 in this example extending between the leg parts iSa, lYa adjacent to, but above where the links 25, 26 are pivoted to the respective leg parts 18a, 19a. In another example) provided this does not interfere with the action of the links 25, 26, the brace 35 may be level with or even below the pivots P1, P2 of the links to the leg parts ISa, 19a.

In the example the stabilising member 22 includes a pair of feet Fl, F2. These feet Fl, F2 do not provide any levelling function per se, but are provided to improve the grip between the stabilisirig member 22 and the ground S. It will be appreciated that the weight of the step ladder 10 plus the weight of any user climbing on the step ladder 10 will fend to cause the links 25, 26 to pivot apart as the pivotal connections P3, P4 of the links 25, 26 at the lower ends to the stabilising member 22 are closer together than the pivotal connections P1, P2 of the links 25, 26 to the front leg parts 18a, 19a, However because the distance between the legs 18, 19 is maintained by the brace 35, this merely results in the structure locking up as the links 25, 26 settle at respective angles to the front legs 18, 19 and to the stabilising member 22.

Because the rear legs 14, 15 of the step ladder 10 are supported on the ground, the stabilisation device 20 affords an overall stability to the step ladder 10. As suggested in figure 2a, where there is very inclined ground S beneath the front legs 18, 19, and the rear legs 14, 15 are on flatter ground, the stabilisation device 20 actually levels the step ladder 10. If the ground beneath the rear legs 14, 15 is as inclined as the ground S beneath the front legs 15, although the step ladder 10 may incline sideways, provided this is not to a degree which would cause ladder imbalance, the stabilisation device 10 will align and lock the step ladder 10 and provide a "wobble" free support.

Figure 3 shows a similar stabilisation device 20 to that of the previous figures and thus similar parts are indicated by the same references.

In figure 3, the links 25, 26 extend downwardly from their pivotal connections P1, P2 to the leg parts I Ba, I 9a, away from one another. In this embodiment,

B

the stabilising member 22 length is extended beyond the base width of the step ladder 10 and the distance between the pivot connections P3, P4 where the links 25, 26 are pivoted to the stabilising member 22, is greater than the distance between the pivot points P1, P2 where the links 25, 26 are pivoted to the leg parts 18a, 18b.

Such an arrangement may be advantageous where the step (or other) ladder lOis tall.

In this example, the brace 35 maintains the spacing apart of the legs 18, 19 which the links 25, 26 will in use, tend to move together.

Various modifications may be made within the scope of the present invention.

In the examples, the leg parts 18a, 19a to which the links 25, 26 are pivoted, are each inline with the remainder of the respective front leg 18, 19 of the step ladder 10. In another embodiment, where the links 25, 26 extend from their pivots P1, P2 to the leg parts 18a, 19a downwardly away from one another, the leg parts 1 Ba, I 9a to which the links 25, 26 are pivoted at P1, P2, may be located beyond the respective legs 18, 19 of the step ladder 10, so that the distance between the two pivots P1, P2 between the links 25, 26 and the leg parts 18a, 19a, is greater than the distance between the legs 18, 19 of the step ladder 10. Thus the leg parts ISa, 18b may be secured relative to the legs 18, 19 proper of the step ladder 10.

This has the effect of increasing the base width of the step ladder 10 which is particularly useful where the ladder 10 is tall.

In the examples described, the stabilisation device 20 is an integral part of the step ladder 10 and thus is provided as original equipment on the remainder of the step ladder 10. Thus the brace 35 is an integral part of the structure of the step ladder 10 and would be provided whether or not the step ladder 10 is fitted with a stabilisation device 20.

However in another example, the stabilising device 20 may be provided as an attachment for an existing ladder. Such an attachment stabilisation device may have its own leg parts which are attached to existing leg parts of the ladder proper, or the links of the stabitisation device 20 may be adapted to be secured e.g. by clamps or the like, to the existing leg parts ISa, 19a of the ladder proper, in a manner so as to permit of pivoting of the links 25, 26 relative to the leg parts 18a, 19a as described above.

Although the invention has been described in relation to a stabilisation device for a four-legged step ladder, the invention may usefully be employed to stabilise lean-to two-legged type ladders, and to four-legged apparatus and structures generally.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAI MS1. A stabflisation device for stabilising the standing of a four-legged apparatus on a support surface, the device including a stabilising member which is secured relative to each of two legs of the apparatus, by a respective link, each link being pivoted relative to the stabilising member and relative to a leg part of a respective leg so that the links extend from the respective leg pivots in opposite directions to the stabilising member at a respective angle to both the leg and the stabilising member, and there being a brace to maintain the distance apart between the two legs.
2. A device according to claim I wherein the links extend downwardly from the leg pivots towards one another.
3, A device according to claim 1 wherein the links extend downwardly from the leg pivots away from one another.
4. A device according to any one of claims I to 3 wherein the leg parts are integral with the respective legs of the apparatus, the stabilisation device being provided as an integral part of the apparatus.
5. A device according to any one of claims 1 to 3 wherein the leg parts of the stabilising device are secured to the respective legs of the apparatus.
6. A device according to any one of the preceding claims wherein the brace is located above the links.
7. A device according to claim 6 wherein dependant on claim 4 wherein the brace is an integral part of the apparatus.
8. A device according to dairn 6 where dependant on claim 5 wherein the brace is an additional component which is secured to each of the two legs or leg pads.
9. A device according to any one of the preceding claims wherein the leg parts to which the links are pivoted, are each in-line with the remainder of the respective leg of the apparatus.
A device according to any one of claims I to S wherein the Eeg parts to which the links are pivoted are located outwardly beyond the respective leg of the apparatus, so that the distance between the two pivots between the links and the leg parts1 is greater than the distance between the legs of the apparatus.
11. A device according to any one of the preceding claims wherein the stabilising member is a solid bar or hollow elongate fabrication.
12 A device according to claim 11 wherein the stabilising member includes feet which improve grip between the stabilising member and theground.
13. A device according to any one of the preceding claims wherefti at least one of the links is provided by a pair of parallel plates which are coupled together at their one ends, either side of the leg part, by an axle which passes through the leg part, thus to provide the pivot connection between the link and leg, and similarly the plates are coupled together at their other ends, either side of the stabilising member, by an axle which passes through the stabilising member, thus to provide the pivot connection between the link and the stabilising member.
14. A device according to any one of the preceding claims wherein the apparatus is a step ladder.
15. A stabilisation device for stabilising the standing of a adder on a support surface, the device including a stabUising member which is secured relative to each of two legs of the ladder, by a respective link, each link being pivoted relative to the stabilising member and relative to a leg part of a respective leg so that the links extend from the respective leg pivots in opposite directions to the stabilising member at a respective angle to both of the legs and the stabihsing member, and there being a brace to maintain the distance apart between the two legs.
16. A device according to claim 15 for a step ladder having two rear legs between which rungs or steps extend, and two front legs, each hinged to a respective rear leg.
17. A device according to claim 16 wherein the stabilising member of the stabilisation device is secured to the pair of front legs by the links.
18. A device according to claim 15 wherein the device is For a lean-to ladder which includes a pair of legs only with ladder rungs extending between the legs, the links of the stabilisation device being pivoted to respective leg parts of the only two legs of the ladder.
19, A stabilisation device as hereinbefore described with reference to and/or as shown in the accompanying drawings.
20. A ladder including or having attached thereto a stabilisation device according to any one of preceding claims.
21. A ladder substantially as hereinbefore described with reference to andlor as shown in the accompanying drawings.
22. Any novel feature or novel combination of features descilbed herein andlor as shown In the accompanying drawings.