GB2144168A - Ladder stabiliser - Google Patents

Abstract

The present invention provides a ladder stabiliser 2 comprising a cross-member 4 having a length greater than the width of a ladder 1 and provided with spaced apart engagement means 8 to either side of a central portion 5 for engagement with a wall 9 to either side of the ladder 2. The stabiliser 2 has mounting means at the central portion 5 for securing the cross-member 4 to the ladder 1 so as to extend substantially transversely of the ladder. The engagement means comprise wheel means 8 rotatably mounted in wheel support means 7 pivotally connected 25,26 to said cross-member 4 for movement in a plane generally at rightangles to the principal plane in which the wheels 8 rotate, between a stabilising position in which the wheels 8 are supported transversely of the cross-member 4 for resisting sideways movement of the ladder 1 in use of the stabiliser 2, and a transfer position in which the wheels 8 are supported generally parallel to the cross-member 4 for facilitating transverse movement of the ladder 1 along the wall 9 in use of the stabiliser 2. <IMAGE>

Description

SPECIFICATION Ladder stabiliser This invention relates to a ladder stabiliser suitable for use in improving the safety of ladders.

It has previously been proposed to improve the safety of ladders by providing attachments with wall engagement means arranged to prevent sideways movement of the ladder relative to the wall; known such devices are however relatively cumbersome and awkward to use, particularly when it is required to move the ladder between a number of different work points along a wall, so much so that they are often not used even when they are available.

It is an object of the present invention to avoid or minimize one or more of the above disadvantages.

The present invention provides a ladder stabiliser for use with a ladder having a predetermined width said stabiliser comprising a cross-member having a length greater than said predetermined width and provided with spaced apart engagement means to either side of a central portion for engagement, in use of the stabiliser, with a wall or the like to either side of the ladder, said stabiliser having mounting means at said central portion for securing said cross-member to said ladder so as to extend substantially transversely of the ladder, said engagement means comprising wheel means rotatably mounted in whell support means pivotally connected to said cross-member for movement in a plane generally at rightangles to the principal plane in which said wheels rotate, between a stabilising position in which the wheels are supported transversely of the cross-member of resisting sideways movement of the ladder in use of the stabiliser, and a transfer position in which the wheels are supported generally parallel to the cross-members forfacilitat- ing transverse movement of the ladder along the wall in use of the stabiliser.

Desirably the stabiliser is provided with remote control means formed and arranged for moving said wheel support means between said positions.

Advantageously there is provided a retaining means formed and arranged for retaining the wheel support means in at least said stabilising position and preferably, alternately in each of said stabilising and transport positions.

Further preferred features and advantages of the present invention will appear from the following detailed description given by way of example of a preferred embodiment illustrated with reference to the accompanying drawings in which: Figure 1 is a general perspective view of a stabiliser of the invention in use on a ladder; Figure 2 is a front elevation of the stabiliser of Figure 1 and part of the ladder; Figure 3 is a general wide elevation of the ladder and stabiliser of Figure 1; and Figure 4 is a detail side elevation of the stabiliser of Figure 1 and part of the ladder on an enlarged scale.

Figure 1 shows a ladder 1 provided with a ladder stabiliser 2 of the invention attached thereto in proximity to its upper end 3. The stabiliser 2 comprises a cross member 4 in the form of a central tubular member 5 with telescopically supported therein outer elements 6 at whose free ends are mounted respective wheel support means 7 with wheels 8. The wheels 8 engage a wall 9 of a building holding the top 3 of the ladder away from the wall 9, while the bottom 10 of the ladder rests in the ground 11 further away from the wall so that the ladder is inclined towards the wail.

As may be seen more readily in Figures 2 and 4 the central cross-member 4 has a generally rectangular sub-frame 12 depending therefrom which rests against the back of the ladder 1 in use of the stabiliser 2. Two first engagement means 13 have generally V-shaped notches 14 facing generally towards the cross-member 4 for engagement with a first rung 15 of the ladder 1, and are mounted on a lower frame cross-piece 16.

Pivotally connected 17 to each frame side member 18 is a second, generally hook-shaped, engagement means 19 having its hooked end 20 engageable with a second rung 21 above the first 15 with the hook opening 22 facing generally away from the crossmember 4 and its other end 23 screwthreadedly engaged in a nut means 24 on the opposite side of the pivotal mounting 17 of said second engagement means 19. The arrangement is such that when the nut means 24 is tightened up longitudinal clamping forces are exerted through the first and second engagement means (both are in pairs) to two different rungs in opposite directions thereby securely clamping the subframe to the ladder.This torm of arrangement is particularly convenient because the subframe can be easily supported against the ladder in a relatively stable manner during connection and disconnection and/or adjustment of the engagement means. This may be contrasted with the rather awkard mounting procedures involved with some earlier designs.

Each wheel support means 7 comprises a tubular support member 25 secured to the free end of the respective outer element 6 in which is slidably and rotatably supported a support leg 26 at whose foot 27 is mounted a wheel 8. The support leg is movable between extended and retracted positions 8a and 8b in which it supports the top of the ladder closer to and further away from the wall respectively, the various positions being secured with the aid of a suitable retaining pin 28.

Each wheel support leg 26 is provided with a radially extending control arm 29 which is privotally connected 30 via a telescopic linkage 31 to a control plate 32 diametrically opposite the other. The control plate 32 is rotatably mounted 33 on the upper cross-piece 34 of the sub-frame 12 and/or the cross-member 4. Intermediate the link connections 30, are provided diametrically opposed shackles 35 via which control cords 36 are connected to the control plate 32 to permit remote operation thereof from the bottom of the ladder.

The control plate 32 is provided with a 90 angle arcuate guide slot 37 for engagement with a guide pin 38 mounted on the cross-piece 34 to limit movement of the control plate 32 and thence the wheel support leg 26 to 900, the arrangement being such that the wheels are movable only between a stabilizing position in which their principal plane extends transversely of the cross-member 4 and a travel position in which the plane is parallel thereto.

In order to prevent accidental shifting between the two positions, the cross-member mounts a safety pin 39 spring biased 40 into a locking position in engagement with the control plate 32 and disengageable therefrom with the aid of a remote control operating cord 41.

In use of the stabiliser, it is secured to the ladder as indicated above and the wheels locked in the stabilising position. The ladder is then driven up the wall into a working position as shown in Figure 3 in which the wheels prevent lateral movement of the top of the ladder. When it is desired to move the ladder along the wall the safety pin is retracted and the control plate rotated through 90" to bring the wheels into the travel position as shown in Figure 1.

The ladder may now be very easily moved along the wall to the new position whereupon the wheels are returned again to their stabilising position.

Claims (16)

1. A ladder stabiliser for use with a ladder having a predetermined width said stabiliser comprising a cross-member having a length greater than said predetermined width and provided with spaced apart engagement means to either side of a central portion for engagement, in use of the stabiliser, with a wall or the like to either side of the ladder, said stabiliser having mounting means at said central portion for securing said cross-memberto said ladder so as to extend substantially transversely of the ladder, said engagement means comprising wheel means rotatably mounted by wheel support means pivotally connected to said cross-member for movement in a plane generally at right angles to the principal plane in which said wheels rotate between a stabilising position in which the wheels are supported transversely of the cross-member for resisting sideways movement of the ladder in use of the stabiliser, and a transfer position in which the wheels are supported generally parallel to the cross-member for facilitating transverse movement of the ladder along the wall in use of the stabiliser.

2. A stabiliser according to claim 1 wherein is provided a remote control means formed and arranged for moving said wheel support means between said positions.

3. A stabiliser according to claim 1 or claim 2 wherein is provided a retaining means formed and arranged for retaining the wheel support means in at least said stabilisation positions.

4. A stabiliser according to claim 3 wherein said retaining means is formed and arranged for retaining said wheel support means alternately in each of said stabilising and transfer positions.

5. A stabiliser according to any one of claims 1 to 4wherein said cross-member comprises outer portions telescopically connected to said central portion.

6. A stabiliser according to any one of claims 1 to 5 wherein said central member has a generally rectangular sub-frame depending therefrom.

7. A stabiliser according to claim 6 wherein said sub-frame is formed and arranged for engagement with the back of the ladder facing the wall, in use of the stabiliser.

8. A stabiliser according to claim 6 or claim 7 wherein a lower cross-piece of the sub-frame has two laterally spaced apart general V-or U-shaped recess means facing generally in a direction parallel to said sub-frame for engagement with a first rung of the ladder in use of the stabiliser.

9. A stabiliser according to claim 8 wherein said sub-frame is provided with a generally hook-shaped engagement means secured to said sub-frame by a securing means so as to be engagable, in use of the stabiliser, with a second rung, with the mouth of said engagement means facing said generally V- or U-shaped recess means, said securing means being formed and arranged for progressively drawing said engagement and recess means towards each other, thereby clamping said first and second rungs therebetween to secure said sub-frame to said ladder.

10. A stabiliser according to claim 9 wherein said engagement means has a screw-threaded portion and said securing means comprises a mounting member pivotally connected to the sub-frame and through which the engagement means extends slidably, and a complementary screw-threaded member in screw-threaded engagement with said engagement means portion and in abutment with said mounting member.

11. A stabiliser according to claim 10 wherein said engagement means comprises at least two laterally spaced apart engagement members with respective securing means.

12. A stabiliser according to any one of claims 1 to 11 wherein is provided a remote control means for moving each of said wheel support means between said positions, each of said remote control means being generally in the form of a parallelogram linkage means having a fixed member constituted by the cross-member, a movable member parallel to said fixed member and connected thereto by first and second link means, with the first link means rigidly secured to the wheel support means for rotation together therewith and the second link means having an elongate drive means connected thereto for operation, in use of the stabiliser from the base of the ladder.

13. A stabiliser according to claim 12 wherein said second link means are constituted by a rotatable control plate and said elongate drive means comprises two elongate flexible members extending from substantially angularly spaced parts of said control plate.

14. A stabiliser according to any one of claims 1 to 13 wherein said wheel support means are telescopic.

15. A ladder stabiliser substantially as described hereinbefore with particular reference to the accompanying drawings.

16. A ladder stabiliser according to any one of claims 1 to 15 where secured to a ladder.