GB2537143A

GB2537143A - A stabilising device

Info

Publication number: GB2537143A
Application number: GB1506016.3A
Authority: GB
Inventors: Akhtar Mubashir
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-09
Filing date: 2015-04-09
Publication date: 2016-10-12
Anticipated expiration: 2035-04-09
Also published as: GB2537143B; GB2538852A; GB2538852B; GB201506016D0

Abstract

The present invention relates to a stabilising device for ladders. The device 10 is designed for a stepladder 18 with two side rails 14, 16 and hollow tubular rungs 20. The mechanism includes a clamp body designed to be placed adjoining a side rail of the ladder with two clamp faces 28, 30. The fastener features a mechanism 32 which moves the two clamp surfaces, so they hold onto a section of the side rail. A rung grip device 34 extends from the clamp and is received within the interior of a tubular rung. A leg 40 mounted at one end 42 on the clamp body so that the opposite end rotates about an axis 44 perpendicular to its second surface 24. The mechanism may feature a lock 46 for securing the leg at a fixed angle and a stop (48, Figure 4) limiting the movement of the leg.

Description

A stabilising device

Field of the Invention

The present invention relates to devices to stabilise devices, in particular to stabilising devices for ladders, more particularly but not exclusively stabilising legs attachable to a ladder in use.

Background

It is known to stabilise ladders against slipping, in particular on uneven, sloping or slippery ground. A variety of devices are known to achieve this, typically comprising a leg that is attachable to the ladder that will provide extra footing and friction against movement parallel to the ladder -i.e. the feet of the ladder slip backwards from the wall or building -or movement transverse to it -i.e. the ladder sways sideways. The present invention provides a convenient stabilising device to counter the former, that is easily fixed to the ladder and readily adjustable when in place, and may be retrofitted to existing ladders.

Prior Art

Accordingly a number of patent applications have been filed in an attempt to resolve the problem or similar, including the following: US20120048647 which discloses: A ladder system is disclosed which allows for stabilizing a ladder on multiple surfaces without the need for a second person or a great deal of setup time. The collapsible ladder system includes a larger ladder section and a smaller ladder strut section which are pivotally connected at a point which is at or below the midpoint of the larger ladder section. The larger ladder section and smaller ladder strut section are connected by a rigid adjustable linkage, or spreader, at a point that is below the pivotable connection. The ladder further includes a means for stability on a variety of surfaces. At the ground contact point, the point where the ladder side rail ends and the ground meet, there are adjustable gripping feet, which can be independently or in combination vertically or angularly adjusted for maximum stability.

This device requires a permanent fixture to the ladder and needs modification -i.e. holes drilled in the side rails of the ladder to fix the device to the side rails, which means it is suitable only for inclusion at the manufacturing stage.

US20140131541 discloses: According to principles of the present inventive concepts, a ladder safety device can include one or more stabilizing legs configured to be removably or permanently attached to a ladder. In a preferred embodiment, an attachment mechanism of the ladder safety device removably attaches to the ladder through rung holes already present in the ladder. The stabilizing legs are preferably secured in the attachment mechanism such that they can be securely oriented at a desired angle extending away from the ladder legs and can be independently extended to have a desired length.

This device has legs that may be extended transversely from the ladder, but which do not extend in the direction parallel to the ladder. Therefore they only protect against transverse slippage of the ladder.

In contrast the present invention provides a device that will protect against slippage parallel to the ladder.

Summary of the Invention

According to the present invention there is provided a stabilising device for a ladder 25 comprising two side rails joined by hollow tubular rungs, the device comprising: a clamp body having a first clamp surface and an opposed second clamp surface, the first surface adapted to mount adjacent to a side rail of the ladder; a clamp mechanism adapted to move first and second clamp surfaces to clamp the clamp body onto a portion of the side rail; a rung grip device extending from the clamp body adapted to be received within the interior of a tubular rung; and an elongate leg mounted at a first end onto the second clamp surface of the clamp body such that a second opposed end of the leg is rotatable about an axis extending substantially perpendicular to the second clamp surface.

In some embodiments the leg comprises a locking means operable to lock the leg at a chosen angular position with respect to the clamp.

In some embodiments the leg is separable from the clamp.

In some embodiments the rung grip device comprises an actuation device adapted to expand within the rung to grip the internal surface of the rung, In some embodiments the clamp body comprises a leg rotation stop to control the range of angular rotation of the leg relative to the clamp body, such that in use the stop determines a minimum angle at which the leg may be set relative to the side rail. In this way the rotation stop ensures a large enough angle relative to the side rail to provide an acceptable degree of stabilisation in use, such that the device comprises a safety means to prevent the leg from being set at too narrow an angle relative to the side rail when in use.

In some embodiments the apparatus comprises a first and a second assembly, each assembly comprising a clamp, a leg and a locking means, wherein the first and second assemblies are configured to mount on and to stabilise the first and the 20 second side rails of the ladder.

In some embodiments the device is configured such that the leg may be mounted in a first angular orientation with respect to the clamp body to adapt the device for use on the right side rail and a second angular orientation with respect to the clamp body 25 to adapt the device for use on the left side rail.

In this way the device may be adapted to mount securely on a side rail of a ladder standing on the ground, with the rung grip device within the inside of a hollow tubular rung and actuated to grip the inside of the rung, and the first and second clamp faces on opposing sides of the side rail and clamped to the rail; the leg is mounted on the clamp and locked at a chosen angle such that the second end of the leg distal from the first is in contact with the ground to stabilise the ladder. A first and a second device may be used to stabilise both legs. The variable angle of the leg with respect to the clamp, and hence with respect to the side rail allows the leg to stabilise the side rail at a chosen angle of the ladder with respect to the ground, and to compensate for variable height or slope of the ground.

The clamp mechanism may comprise a rotatable knob and a gear mechanism to connect rotation of the knob to movement of the clamp faces towards or away from each other, for example comprising a rotating gear connected to the knob and one or 5 more linear racks attached to one or both clamp faces and engaging with the gear.

The rung grip device may comprise: a hollow cylindrical body extending from the first clamp surface of the clamp body, a deformable hollow bung mounted around the outside of the cylindrical body and movable with respect to it, a nut connected to the distal end of the bung such that the nut and the bung are rotatably fixed with respect to one another, a clearance hole extending through the clamp body and aligned coaxially with the cylindrical member, and a bung bolt configured to pass through the clearance hole and the distal nut.

In this way, tightening of the bung bolt may cause the distal nut to be drawn towards the clamp body, so compressing the bung and causing it to expand outwards to grip the internal surface of the rung.

In some embodiments the rung grip comprises: a support member extending from the first clamp surface of the clamp body and adapted to pass inside the rung, a distal nut free to slide within the support member and rotatably fixed with respect to the support member, a wing member pivoted to the support member and pivoted to the distal nut, a clearance hole extending through the clamp body and aligned coaxially with the distal nut, and a bung bolt configured to pass through the clearance hole and the distal nut.

In this way, tightening of the bung bolt causes the distal nut to be drawn towards the clamp body, so causing the wing to pivot with respect to the support member and causing it to expand outwards to grip the internal surface of the rung.

In some embodiments the locking means comprises a twist grip knob mounted fixedly on a screw thread, the leg comprises a clearance hole for the screw thread and the clamp body comprises a threaded hole provided on its second face to receive the screw thread. In this way the screw thread may be passed through the clearance hole in the leg and into the threaded hole, tightening the screw thread using the twist grip knob then acting to clamp the leg to the second face of the clamp body. In some embodiments the second face comprises a substantially cylindrical projection and the threaded hole is coaxial with the projection, and the first end of the leg comprises a substantially cylindrical recess to receive the projection. In this way in use the leg may be located correctly with respect to the clamp body and force on the leg parallel to the clamp body may be taken in use by contact between the projection and the inner wall of the recess. In some embodiments the projection and the recess may comprise one or more stepped profiles around their circumference. The stepped profiles may act to provide friction against rotary movement of the leg relative to the clamp body. The stepped profiles may be configured such that the leg may move axially relative to the clamp body between a first, outward position in which the leg is free to rotate relative to the clamp body and a second, inward position adjacent to the second surface of the clamp body in which the stepped profiles engage to prevent rotation of the leg relative to the clamp body. In this way the leg may be fitted to the clamp body, rotated to the correct angular position, and then moved towards the clamp body to hold it in place against rotation. The twist grip knob may then be tightened to lock the leg in place.

In some embodiments the device comprises a foot articulated to the second end of the leg.

Brief Description of Figures

Figure 1 shows an isometric embodiment of two devices according to the invention in place on each side rail of a ladder.

Figure 2 shows an isometric view of the two devices as shown in figure 1.

Figure 3 shows a front elevation of a device according to the invention.

Figure 4 shows an exploded view of the device shown in figure 3.

Figure 5 shows an exploded view of the device ready to mount onto the rung and side rail of a ladder.

Figure 6 shows an exploded view of the clamp body of a device according to the invention.

Detailed Description of Figures

Referring to figures 1 to 6, an embodiment 10 of the invention comprises: A clamp 12 to configured to mount on a side rail 14, 16 of a ladder 18 having two 5 side rails joined by hollow tubular rungs 20, the clamp comprising: A clamp body 22 having a first surface 24 adapted to mount adjacent to the side rail when the clamp is in position on the side rail and an opposing second surface 26, A first 28 and second 30 clamp faces slidably mounted on the first surface of the clamp body and movable towards and away from each other to receive a portion of the side rail between them, A clamp mechanism 32 mounted on the clamp body adapted to move the first and second clamp faces towards and away from each other to clamp onto the side rail, and A rung grip device 34 adapted to pass into the interior of a tubular rung 20, the rung grip device being mounted on the first surface 24 of the clamp body and extending from it, the rung grip device comprising an actuation device adapted to expand within the rung to grip the internal surface of the rung, and An elongated leg 40 mounted at its first end 42 on the second surface 26 of the 20 clamp body and rotatable about an axis 44 substantially perpendicular to the second surface, and A locking means 46 operable to lock the leg at a chosen angular position with respect to the clamp.

In this embodiment the leg 40 is separable from the clamp 12.

In this embodiment the clamp body 22 comprises a leg rotation stop 48 to control the range of angular rotation of the leg relative to the clamp body, such that in use the stop determines a minimum angle at which the leg may be set relative to the side rail.

In this way the rotation stop ensures a large enough angle relative to the side rail to provide an acceptable degree of stabilisation in use, such that the device comprises a safety means to prevent the leg from being set at too narrow an angle relative to the side rail when in use.

In this embodiment the device is configured such that the leg may be mounted in a first angular orientation with respect to the clamp body to adapt the device for use on the right side rail and a second angular orientation with respect to the clamp body to adapt the device for use on the left side rail. The clamp body comprises a first leg rotation stop 48, to control the range of angular rotation of the leg relative to the clamp body when in use on the right hand rail 14 and a second leg rotation stop 50, to control the range of angular rotation of the leg relative to the clamp body when in use on the left hand rail 16.

In this way the device is adapted to mount securely on a side rail of a ladder standing on the ground, with the rung grip device within the inside of a hollow tubular rung and actuated to grip the inside of the rung, and the first and second clamp faces on opposing sides of the side rail and clamped to the rail; the leg is mounted on the clamp and locked at a chosen angle such that the second end of the leg distal from the first is in contact with the ground to stabilise the ladder. A left and a right hand device may be used to stabilise both legs. The variable angle of the leg with respect to the clamp, and hence with respect to the side rail allows the leg to stabilise the side rail at a chosen angle of the ladder with respect to the ground, and to compensate for variable height or slope of the ground.

The clamp mechanism 32 comprises a rotatable knob 52 and a gear mechanism 54 to connect rotation of the knob to movement of the clamp faces 28, 30 towards or away from each other, for example comprising a rotating gear connected to the knob and one or more linear racks attached to one or both clamp faces and engaging with the gear.

The rung grip device 34 comprises: a hollow cylindrical body 60 extending from the first face 24 of the clamp body, a deformable hollow bung 62 mounted around the outside of the cylindrical body and movable with respect to it, a nut 64 connected to the distal end of the bung such that the nut and the bung may 30 not rotate with respect to one another, a clearance hole 66 through the clamp body coaxial with the cylindrical member, and a bung bolt 68 passing through the clearance hole and the distal nut.

In this way, tightening of the bung bolt 68 causes the nut 64 to be drawn towards the 35 clamp body, so compressing the bung 62 and causing it to expand outwards to grip the internal surface of the rung.

In this embodiment the locking means 46 comprises a twist grip knob 70 mounted fixedly on a screw thread 72, the leg 40 comprises a clearance hole 74 for the screw thread and the clamp body comprises a threaded hole 66 (also the clearance hole for the bung bolt 68) provided on its second face to receive the screw thread. In this way the screw thread may be passed through the clearance hole 74 in the leg and into the threaded hole 66, tightening the screw thread using the twist grip knob then acting to clamp the leg to the second face of the clamp body. In this embodiment the second face 26 of the clamp body comprises a substantially cylindrical projection 76 and the threaded hole is coaxial with the projection, and the first end 42 of the leg comprises a substantially cylindrical recess to receive the projection 76. In this way in use the leg may be located correctly with respect to the clamp body and force on the leg parallel to the clamp body may be taken in use by contact between the projection and the inner wall of the recess. In this embodiment the projection 76 and the recess comprise a stepped profile 78 around their circumference. The stepped profiles acts to provide friction against rotary movement of the leg relative to the clamp body. In some variants of the embodiment the stepped profile may be configured such that the leg may move axially relative to the clamp body between a first, outward position in which the leg is free to rotate relative to the clamp body and a second, inward position adjacent to the second surface of the clamp body in which the stepped profiles engage to prevent rotation of the leg relative to the clamp body. In this way the leg may be fitted to the clamp body, rotated to the correct angular position, and then moved towards the clamp body to hold it in place against rotation. The twist grip knob may then be tightened to lock the leg in place.

In this embodiment the device comprises a foot 80 articulated to the second end 82 of the leg.

It is an advantage of the device that the leg 40 may be moved to a position parallel 30 to, and pointing in the direction upwards alongside, the side rail, and locked in place so that the ladder may be stored with the device in place.

The invention has been described by way of examples only and it will be appreciated that variation may be made to the above-mentioned embodiments without departing 35 from the scope of invention. Firstly it will be understood that any features described in relation to any particular embodiment may be featured in combinations with other embodiments.

With respect to the specification therefore, it is to be realised that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered as illustrative only of the principles of the invention, with variation and implementation obvious and clear on the basis of either common general knowledge or of expert knowledge in the field concerned. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as set out in the accompanying claims.

Claims

Claims 1. A stabilising device for a ladder comprising two side rails joined by hollow tubular rungs, the device comprising: a clamp body having a first clamp surface and an opposed second clamp surface, the first surface adapted to mount adjacent to a side rail of the ladder; a clamp mechanism adapted to move first and second clamp surfaces to clamp the clamp body onto a portion of the side rail; a rung grip device extending from the clamp body adapted to be received within the interior of a tubular rung; and an elongate leg mounted at a first end onto the second clamp surface of the clamp body such that a second opposed end of the leg is rotatable about an axis extending substantially perpendicular to the second clamp surface.
2. A device according to claim 1 further comprising a locking means operable to lock the leg at a predetermined angular position with respect to the clamp.
3. A device according to claim 1 or claim 2 wherein the rung grip device comprises an actuation device adapted to expand within the rung to grip the internal surface of the rung,
4. A device according to claim 1, 2 or 3 wherein the leg is separable from the clamp.
5. A device according to any of the preceding claims wherein the clamp body comprises a leg rotation stop to control the range of angular rotation of the leg relative to the clamp body.
6. An apparatus comprising a first and second device according to any preceding claim comprising a first and a second assembly, each assembly comprising a clamp, a leg and a locking means, wherein the left and right hand assemblies are configured to mount on and to stabilise the first and the second side rails of the ladder.
7. A device according to any preceding claim configured such that the leg is mountable in a first angular orientation with respect to the clamp body to adapt the device for use on the right side rail and a second angular orientation with respect to the clamp body to adapt the device for use on the left side rail.
8. A device according to any preceding claim wherein the clamp mechanism comprises a rotatable knob and a gear mechanism to connect rotation of the knob to movement of the clamp faces towards or away from each other. 10
9. A device according to any preceding claim wherein rung grip device comprises: a hollow cylindrical body extending from the first face of the clamp body, a deformable hollow bung mounted around the outside of the cylindrical body and movable with respect to it, a nut connected to the distal end of the bung such that the nut and the bung are rotatably fixed with respect to one another, a clearance hole extending through the clamp body and aligned coaxially with the cylindrical member, and a bung bolt arranged to pass through the clearance hole and the distal nut.
10. A device according to any of claims 1 to 9 wherein the rung grip comprises: a support member extending from the first surface of the clamp body and adapted to pass inside the rung, a distal nut free to slide within the support member but not to rotate with respect to the support member, a wing member pivoted to the support member and pivoted to the distal nut, a clearance hole extending through the clamp body and aligned coaxially with the distal nut, and a bung bolt arranged in use to pass through the clearance hole and the distal nut.
11. A device according to any preceding claim wherein a locking means for rotation of the leg comprises a twist grip knob mounted fixedly on a screw thread, the leg comprises a clearance hole for the screw thread and the clamp body comprises a threaded hole provided on its second face to receive the screw thread.
12. A device according to any preceding claim wherein the second face of the clamp body comprises a substantially cylindrical projection and the threaded hole is coaxial with the projection, and the first end of the leg comprises a substantially cylindrical recess to receive the projection.
13. A device according to any preceding claim wherein the projection and the recess comprise one or more stepped profiles around their circumference.
14. A device according to claim wherein the stepped profiles are configured such that the leg may move axially relative to the clamp body between a first, outward position in which the leg is free to rotate relative to the clamp body and a second, inward position adjacent to the second surface of the clamp body in which the stepped profiles engage to prevent rotation of the leg relative to the clamp body.
15. A device according to any preceding claim comprising a foot articulated to the second end of the leg.