GB2483692A

GB2483692A - Ladder stabiliser

Info

Publication number: GB2483692A
Application number: GB201015534A
Authority: GB
Inventors: Adrian Lowes
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-09-17
Filing date: 2010-09-17
Publication date: 2012-03-21
Also published as: GB201015534D0

Abstract

A ladder stabiliser includes a ladder support 1 arranged to support a ladder, a base 13, 14, 15, 16 and a locking system (2, 3, 4, 7, fig 3). The base is arranged to be seated on the ground, the ladder support being pivotally coupled (2, 3, fig 3) to the base to permit rotational movement between the ladder support and the base about three orthogonal axes. The locking system is arranged to lock the position of the ladder support relative to the base. The locking system may use a hand actuated cam.

Description

-I-

A ladder Stabiliser The present invention relates to a ladder stabiliser which supports and secures the base of a ladder. In particular the present invention enables a user to move a ladder through three axis of movement to achieve the desired angular and rotational position. in certain embodiments a hand operated locking device secures the ladder in the desired position.

Many accidents and fatalities occur through the use of ladders which are incorrectly secured at the base end on uneven surfaces. It is also difficult to manoeuvre long ladders in to a desired vertical resting position when resting the bottom of the ladders on the ground.

There are other inventions surrounding the securing of the bases of ladders. Published UK patent application GB-2420 146-A discloses a ladder stabiliser including a ball and socket arrangement; however this is only on a stabilising foot and plays no part in ladder alignment and setup. Furthermore, there is no facility to lock the ball and socket assembly.

It is an object of embodiments of the present invention to obviate or mitigate one or more of the problems associated with the prior art, whether identified herein or elsewhere. In particular, it is an object of embodiments of the present invention to provide a ladder stabiliser enabling an operator to set up ladders on uneven or angled surfaces and on stairways, providing a safe and stable, working platform.

According to the present invention there is provided a ladder stabiliser comprising: a ladder support arranged to support a ladder; a base arranged to be seated on the ground, the ladder support being pivotally coupled to the base to permit rotational movement between the ladder support and the base about three orthogonal axes; and a locking system to lock the position of the ladder support relative to the base.

Advantageously, the present invention significantly increases the stability of a ladder relative to a ladder supported directly on the ground. Furthermore, a ladder may be more quickly and safely positioned against a wall when the ground is uneven or sloping due to the three-axis movement between the ladder support (and hence the ladder) and the base (and hence the ground). Once in position, the ladder is locked in place to prevent further rotational movement, providing the operator with a more secure working platform.

Preferably, the base comprises a frame having legs and the ladder support comprises a tray arranged to receive an end of a ladder.

Preferably, the pivotal connection permits rotational movement between the tray and the frame about three orthogonal axes.

Preferably, the tray is coupled to the frame via a ball a socket joint, the ball being coupled to the underside of the tray and the socket being coupled to the frame.

The frame may extend around the tray with a cross bar extending across a central portion of the frame, the socket being coupled to the cross bar.

Preferably, the socket comprises a first jaw fixed to the frame and having a concave face to engage a first side of the ball and a second jaw arranged to slide relative to the first jaw and having a concave face to engage a second side of the ball opposite to the first side.

The ladder stabiliser may further comprise a push rod coupled to the frame and arranged to apply a linear force to the second jaw so that the ball is compressed between the first and second jaws to limit rotational movement between the tray and the frame.

The ladder stabiliser may further comprise a handle pivotally coupled to the frame and having a cam portion arranged to transfer a linear force to the push rod when the handle is rotated relative to the frame.

The legs may be pivotally coupled to the frame such that they can rotate about an axis lying in a plane defined by the frame, the legs further comprising a locking mechanism to lock the rotational position of each leg relative to the frame.

At least one of the ball and the concave faces of the jaws maybe treated to increase its friction.

The jaws may be coupled together via at least one pin having an interference fit in a bore extending into one jaw and a sliding fit in a bore extending into the other jaw.

An embodiment of the present invention comprises a ladder stabiliser having a frame with four legs which have adjustable rotational positions for setting up a rough level platform.

The frame supports a locking socket arrangement. The locking system is a cam lock which applies pressure to the socket and hence applies pressure to the ball, acting as a brake assembly. Alternatively, the locking system could be hydraulically actuated. The base end of a ladder is placed on a fabricated tray having a ball attached to the underside of the tray, which fits into the locking socket assembly. The ball and socket provide continuously variable adjustment through three axis (within predefined limits) to give the operator an ideal ladder position. Once a preferred position is achieved the ball and socket assembly is locked to prevent further relative movement. The same principle of three-axis movement could also be achieved using a gyroscopic assembly in replacement of a ball and socket assembly, as will be readily apparent to the appropriately skilled person.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a ladder stabiliser in accordance with an embodiment of the present invention; Figure 2 is a side view of the ladder stabiliscr of figure 1; Figure 3 is a vertical sectional view of the ladder stabiliser of figure 1 along the line A:A in the direction of the arrows illustrating detail of the ball and socket joint; Figure 4 is a vertical sectional view of the ladder stabiliscr of figure 1 along the line B:B in the direction of the arrows illustrating detail of a supporting leg; Figure 5 is an isometric projection of the ladder stabiliser of figure 1 from above; Figure 6 is an isometric projection of the ladder stabiliser of figure 1 from below; Figure 7 is a side view of the ladder stabiliser of figure 1; Figure 8 is a horizontal sectional view of the ladder stabiliser of figure 1 along the line C:C in the direction of the arrows illustrating detail of the ball and socket joint; Figure 9 is an isometric projection of the ladder stabiliser of figure 1 with a ladder in position; Figure 10 is an end view of the ladder stabiliser of figure 1 with a ladder in position illustrating the extent of rotational movement about a first axis; Figure 11 is a side view of the ladder stabiliser of figure 1 with a ladder in position illustrating the extent of rotational movement about a second axis orthogonal to the first axis; and Figure 10 is a plan view of the ladder stabiliser of figure 1 with a ladder in position; Referring first to figures 1 and 2, these respectively show a plan view and a side view of a ladder stabiliser for supporting the base of a ladder in accordance with an embodiment of the invention. The bottom end or base of a ladder fits into a tray 1. Packing blocks or fixing screws could be applied to eater for varying sized ladders. The tray is attached to a ball 2 on the underside of the tray. The ball 2 has a knurled or high friction outer finish.

The ball could be welded or adhered to the tray depending on the selected material. The ball is retained by a split socket assembly comprising jaws 3, 4 (visible in the vertical sectional view of figure 3). The spherical faces ofjaws 3, 4 which engage ball 2 may also be knurled or otherwise be provided with a high friction finish to engage ball 2.

One jaw 4 of the split socket is fixed to a frame 14. The frame 14 may be generally rectangular extending around the tray. A cross bar 16 extends across the centre of frame 16, and it is to cross bar 16 that the fixed jaw 4 is secured, for instance by welding. Cross bar 16 may comprise a tray to contain jaws 3, 4. The two halves 3, 4 of the split socket are joined together by pins 18 (visible in the horizontal sectional view of figure 8). Pins 18 are interference fitted into fixed jaw 4. The pins 18 pass through movable jaw 3 with a sliding fit. Pins 18 are fastened to a guide plate 19 (again visible in figure 8). A push rod 5 passes through the guide plate 19 with a sliding fit and bears against movable jaw 3.

Hand actuated cam 7 is fixed to the outside of frame 14 by bracket 17 and pivots about bolt 8. The hand actuated cam 7, when rotated relative to frame 14 about bolt 8, applies a linear force to screw adjustment pin 6. Push rod 5 has a female thread and screw adjustment pin 6 has a corresponding male thread. Parts 5 and 6 can be screwed together and apart to adjust the stroke length. A lock nut (not visible) is applied to maintain the selected position between screw adjustment pin 6 and push rod 5. The linear force from hand actuated cam 7 transmits down parts 5 and 6 subtending a force on moving jaw 3, which in turn applies a compressive force between parts 2, 3 and 4 to lock the position of the ball 2 relative to jaws 3, 4.

In an alternative embodiment, cam 7 could be replaced by a hydraulic cylinder to apply force to push rod 5, or directly to the moving jaw 3. A hydraulic pump coupled to a piston generates a linear force, which can be transferred directly or indirectly to the moving jaw 3. The force applied to the jaw 3, and hence the compressive force applied to the ball 2, may be controlled by adjusting the pressure within the piston, for instance by monitoring the developed pressure with a pressure gauge coupled to the pump. Advantageously, a ball and socket joint locking system operating through hydraulic pressure may generate a larger compressive force to the ball, thereby providing a more stable coupling between the tray and the frame. Furthermore, a hydraulically operated locking system is better able accommodate wear in the balI and socket joint that a hand operated cam, which in certain embodiments may require a resilient element such as a coiled spring between the cam and the moveable jaw to ensure consistent compression of the ball, or regular adjustment of the screw adjustment pin.

Leg brackets 15 are coupled to frame 14, as for instance shown in figure 2. Leg brackets 15, along with cross bar tray 16, may be welded or adhered to the frame 14 depending on the selected material. Possible materials for manufacturing embodiments of the present invention include steels, polymers, carbon fibres, glass fibres, ceramics and / or alloys.

Referring to figure 4, this illustrates section B-B of figure 1. At each corner of the frame 14 a leg 13 is coupled to the frame, and specifically to a leg bracket 15. Leg 13 is coupled to a rotational adjustment plate 9 at one end and nonslip foot 12 at the other end. The nonslip foot 12 is push fitted onto leg 13. Rotational adjustment plate 9 is welded or adhered into position on leg 13. The leg assembly formed from parts 13, 9, and 12 sits within brackets 15 and rotate around bolt or pin 10 (shown in figure 2). The leg assembly can be locked into position by passing pin 11 through bracket 15 and through rotational adjustment plate 9 on the leg assembly. The rotational adjustment plate 9 comprises multiple holes so that the angular position of the leg relative to the frame may be varied according to the surface underlying the frame.

Figures 9 to 12 illustrate a device according to the present invention supporting a ladder and show the typical angular range of the ladder relative to the frame 14. Specifically, figure 10 shows that in one embodiment the ladder may pivot about an axis extending through the centre of the ball parallel to the long axis of the frame until the ladder subtends an angle of 67° with the frame. Figure 11 shows that in one embodiment the ladder may pivot about an axis extending through the centre of the ball parallel to the short axis of the frame until the ladder subtends an angle of 64° with the frame. The ladder may also rotate about an axis normal to the plane of the frame as shown in the top view of figure 12.

It will be readily apparent to the appropriately skilled person that certain aspects of the present invention may be readily changed. For instance, the shape of the tray may be varied according to the size and shape of the ladder.

Further modifications to, and applications of, the present invention will be readily apparent from the description herein, without departing from the scope of the appended claims.

Claims

CLAIMS: I. A ladder stabiliser comprising: a ladder support arranged to support a ladder; a base arranged to be seated on the ground, the ladder support being pivotally coupled to the base to permit rotational movement between the ladder support and the base about three orthogonal axes; and a locking system to lock the position of the ladder support relative to the base.
2. A ladder stabiliser according to claim I, wherein the base comprises a frame having legs and the ladder support comprises a tray arranged to receive an end of a ladder.
3. A ladder stabiliser according to claim 2, wherein the pivotal connection permits rotational movement between the tray and the frame about three orthogonal axes.
4. A ladder stabiliser according to claim 2 or claim 3, wherein the tray is coupled to the frame via a ball a socket joint, the ball being coupled to the underside of the tray and the socket being coupled to the frame.
5. A ladder stabiliser according to claim 4, wherein the frame extends around the tray with a cross bar extending across a central portion of the frame, the socket being coupled to the cross bar.
6. A ladder stabiliser according to claim 4 or claim 5, wherein the socket comprises a first jaw fixed to the frame and having a concave face to engage a first side of the ball and a second jaw arranged to slide relative to the first jaw and having a concave face to engage a second side of the ball opposite to the first side.
7. A ladder stabiliser according to claim 6, further comprising a push rod coupled to the frame and arranged to apply a linear force to the second jaw so that the ball is compressed between the first and second jaws to limit rotational movement between the tray and the frame.
8. A ladder stabiliser according to claim 7, further comprising a handle pivotally coupled to the frame and having a cam portion arranged to transfer a linear force to the push rod when the handle is rotated relative to the frame.
9. A ladder stabiliser according to any one of claims 2 to 8, wherein the legs are pivotally coupled to the frame such that they can rotate about an axis lying in a plane defined by the frame, the legs further comprising a locking mechanism to lock the rotational position of each leg relative to the frame.
10. A ladder stabiliser according to claim 6 or any claim dependent thereto, wherein at least one of the ball and the concave faces of the jaws is treated to increase its friction.
11. A ladder stabiliser according to claim 6 or any claim dependent thereto, wherein the jaws are coupled together via at least one pin having an interference fit in a bore extending into one jaw and a sliding fit in a bore extending into the other jaw.