GB2487076A - Hollow-runged ladder with collapsible guardrails and stabilisers - Google Patents

Abstract

A combination hollow-runged ladder 1 with collapsible guardrails 2 includes guardrails that are connected to a pair of spaced-apart swivelable yokes 3, each yoke extending through a respective ladder rung 4, and locking means to lock each yoke and hence the guardrails in an extended position relative to the ladder side rails 7. The uppermost yoke when in use is provided with collapsible wall-engaging stabiliser legs 8 on each side thereof. Each leg has a moveably mounted support arm 12 such that the stabiliser can be folded out and releasably locked in position resting against a wall. The guardrails may be telescopic at their lower most ends, with the telescopable parts (13, fig 2) being ground engageable, and lockable in place to further stabilise the ladder.

Description

I

Ladder with Guardrail Stabilisers This invention relates to hollow-runged ladders, particularly extendable nests of such ladders made of aluminium.

In our pending patent application number GB1011374.4 we have described a ladder with collapsible guardrails supported by pairs of yokes extending either wholly or partially through respective ladder rungs so that the inherent strength of the ladder is not weakened by the use of rivets or other types of fasteners which would otherwise have to be used in order to support guardrails on either side of the ladder. Whilst our aforementioned patent application discloses a ground-engaging stabiliser for use with the ladder so as to prevent or inhibit twisting of the ladder about its major axis, in practice it has been found that a major disadvantage of having a relatively wide stabiliser at the foot of the ladder is that it assumes, firstly, that there is sufficient space available and, secondly, that the ground upon which the ladder is resting is generally flat, both of which conditions are often not met when ladders are used in practice.

The present invention is derived from the realisation that, whatever space or topographic constraints may be at a site where a ladder is to be used, with or without ground engaging stabilisers, the ladder itself is usually leaned against a vertical, generally flat, surface where the possibility of the ladder twisting is increased by the presence of a user of the ladder, who may have to lean over to one side for work purposes at the top end of the ladder, thereby significantly increasing the risk of the ladder twisting.

According to the invention there is provided a combination hollow-runged ladder with collapsible guardrails in which the guardrails are connected to at least a pair of spaced-apart swivelable yokes, each yoke extending through a respective ladder rung, and locking means to lock each yoke and hence the guardrails in an extended position relative to the ladder side rails, characterised in that the uppermost yoke relative to the ladder when in use is provided with collapsible wall engaging stabiliser legs on each side thereof, each leg also having a moveably mounted support arm connected at one end to an intermediate portion of the stabiliser leg and at its other end to the guardrail or the end of the yoke, the arrangement being such that when the ladder has been erected and the guardrails moved to their extended position for use, each stabiliser arm can be folded out and releaseably locked in position resting against a wall or similar surface, to thereby ensure that the risk of twisting of the ladder from the top is substantially reduced.

With this arrangement an extremely stable combination ladder and guardrail assembly can effectively obviate the risk of the ladder twisting during use, particularly if a ground engaging stabiliser also forms part of the ladder.

Conveniently, each stabiliser leg is telescopic so that the length can be adjusted as required.

Advantageously, the support arms are adjustable as to length, such as by the use of turnbuckles by which the angular extent to which each leg can be splayed apart relative to the upper most yoke can be adjusted.

Similarly, the elbows of each yoke may be partly swivelable so that when the ladder is not in use the guardrails may be stored immediately adjacent to the side rails, and when the guardrails are extended out for use they may then be splayed apart within the limit of movement dictated by each elbow joint. This is a particularly advantageous arrangement since it is often necessary to carry tools or materials up ladders which collectively mean that the width required to safely do this is more than the width of the ladder, whereas by being able to splay the guardrails apart by a limited amount this potential problem is obviated.

To further enhance the stability of the combination ladder and guardrails, the guardrails may be telescopic at their lower-most ends remote from the top most end relative to an upright ladder, with the telescopicable parts thereby being ground engageable, in which position they may be releasably locked in place to further stabilise the ladder. Alternatively, the lowermost yoke and/or guardrails may also be provided with stabilizer legs of the type described above but for ground-engaging use, thereby, in combination providing enhanced stability for the ladder at each end thereof.

The invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the upper part of a combination ladder and guardrails having wall engaging stabiliser legs, and Figure 2 is a perspective view of part of the ladder of Figure 1 showing a ground engaging foot extending from one of the guardrails.

Referring firstly to Figure 1, there is shown the upper part of a set of three inter-linked hollow-rung ladders shown generally at 1 incorporating a pair of collapsible guardrails 2 moveably mounted on one of a pair of swivellable yokes shown generally at 3 extending through the uppermost ladder rung 4, the other such yoke (not shown) extending through a lower rung of the ladder 1 and being similarly connected to the other ends of the guardrails 2. Each yoke 3 has a pair of yoke arms 5 to which respective ends of the guardrails 2 are hingeably linked.

The elbow 6 is jointed so that the arms 5 can be splayed apart to the extent shown so that the guardrails 2 are similarly splayed apart relative to the major axis of the ladders 1, the joints 6 therefore allowing the arms 5 to be moved to a respectively parallel position for storage when the guardrails 2 are moved to their stored position immediately next to the side rails 7 of the ladder 1.

In order to prevent twisting of the ladder 1 at its uppermost end a pair of stabiliser legs 8 are provided, each being moveably attached to a respective yoke arm 5 at one end by means of a pivot joint 9 and having a telescopicable foot portion 10 at its free end which may be locked in any desired position via a releasable toggle 11. In order to control movement of each stabiliser leg 8 a support arm 12 is provided between an end part of each guardrail 2 and an intermediate portion of each stabiliser leg 8, although it will be apparent that the support arms 12 could instead be connected to an upper part of each yoke arm 5. In the embodiment shown, each support arm 12 is in the form of an adjustable turnbuckle so that the length of the support arm can be adjusted to, in turn, adjust the angular position of each stabiliser leg relative to the yoke arms 5.

Figure 2 shows the lower part of one half of the ladder I in its upright condition leaning against a wall surface and in which it will be seen that the lower end of the guardrail 2 shown includes a telescopicable foot portion 13 which may be locked in any required position by means of a releasable toggle 14.

In use, the ladder 1 is moved to a generally upright position against e.g. a wall surface and extended to a required height, the yoke arms 5 and attendant guardrails 2 are moved to the position shown in Figure 1, whereafter the respective foot portions 13 extending from each guardrail 2 are extended outwards to engage with the ground, whereafter they are locked in place by means of a toggle lock 14. This stabilises the lower end of the ladder 1 and the upper end of the ladder 1 is stabilised by means of the stabiliser legs 8, whose length and angular orientation relative to the ladder may be adjusted via, respectively, adjustment to the length of the leg portions 10 and/or the respective support arms 12. As a consequence, when the combination of hollow runged ladder I with associated collapsible guardrails 2 are extended out for use both the lower and upper ends are stabilised by, respectively, the stabiliser feet 13 engaging the ground and the stabiliser legs 8 engaging a wall surface, such that a very stable working arrangement can then be established. This is enhanced by the ability of the guardrails 2 to be splayed slightly outwards to the position shown in Figure 1 without compromising safety of a person using the ladder, who may therefore carry tools or materials up or down the ladder in the knowledge that any loss of balance will not result in the ladder twisting, even if the or each guardrail 2 is gripped tightly to prevent e.g. falling.

Claims (8)

1. Claims 1. A combination hollow-runged ladder with collapsible guardrails in which the guardrails are connected to at least a pair of spaced-apart swivelable yokes, each yoke extending through a respective ladder rung, and locking means to lock each yoke and hence the guardrails in an extended position relative to the ladder side rails, characterised in that the uppermost yoke relative to the ladder when in use is provided with collapsible wall engaging stabiliser legs on each side thereof, each leg also having a moveably mounted support arm connected at one end to an intermediate portion of the stabiliser leg and at its other end to the guardrail or the end of the yoke, the arrangement being such that when the adder has been erected and the guardrails moved to their extended position for use, each stabiliser arm can be folded out and releaseably locked in position resting against a wall or similar surface, to thereby ensure that the risk of twisting of the ladder from the top is substantially reduced.
2. 2. The combination according to claim I where the support arms are adjustable as to length.
3. 3. The combination according to claim 2 wherein adjustment of length is by * * the use of turnbuckles by which the angular extent to which each leg can be * !20 splayed apart relative to the upper most yoke can be adjusted.
4. 4. The combination according to any preceding claim wherein the elbows of *s * * each yoke are partly swivelable so that when the ladder is not in use the **t * guardrafls may be stored immediately adjacent to the side rails, and when the guardrails are extended out for use they can then be splayed apart within the limit of movement dictated by each elbow joint.
5. 5. The combination according to any preceding claim wherein the guardrails are telescopic at their lower-most ends remote from the top-most end relative to an upright ladder, with the telescopable parts thereby being ground engageable, in which position they can be releasably locked in place to further stabilise the ladder.
6. 6. The combination according to any preceding claim wherein the lowermost yoke and/or guardrails are provided with stabilizer legs of the type described above for ground-engaging use.

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7. 7 -A-combinationhollow-runged-ladder-with-collapsible-guardrails-in which-----the guardrails are connected to at least a pair of spaced-apart swivelable yokes, each yoke extending through a respective ladder rung, and locking means to lock each yoke and hence the guardrails in an extended position relative to the ladder side rails, wherein the guardrails are telescopic at their lower-most ends remote from the top most end relative to an upright ladder, with the telescopable parts thereby being ground engageable, in which position they may be . : releasably locked in place to stabilise the ladder. * 1*
8. 8. A combination ladder and guardrail substantially as hereinbefore *:s* described with reference to Figure 1 or Figure 2. * *S * 0 *0* * 0.