GB1578143A - Structures supported by an adjustable leg - Google Patents

Description

(54) STRUCTURES SUPPORTED BY AN ADJUSTABLE LEG (71) I, ALAN HENRY KYNASTON, a British Subject, of Kinney Associates Limited, 1 St. George's Road, Park Street, Bristol BS1 5UZ, formerly of 59 Queen Charlotte Street, Queen Square, Bristol BUS 1 4HL, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to structures such as ladders, having a supporting device, and more particularly a device supporting the structure on a non-level surface.

If structures such as ladders are used on non-level surfaces there is a danger that they will overbalance, possibly causing injury.

There is therefore a need for a supporting device which will enhance the stability of such structures on non-level surfaces.

The present invention provides a structure having a device for supporting the structure on a surface, said device comprising a housing rigidly attached to the structure and an elongate second element slidable longitudinally with respect to the housing into one of a plurality of spaced positions which are arranged such that in use the second element forms a variable length leg for engaging with the surface, the housing having a slot therein which is longitudinal with respect to the second element, the second element having a locating member which runs in said slot when the second member slides in the housing, and wherein the slot has transverse recesses to engage the locating member in said positions.

To provide positive location for the locating member, each transverse recess preferably has an edge remote from the surface-engaging end of the second element which rises upwardly away from the slot.

Preferably the locating member is screwthreaded and receives a nut which tightens directly or indirectly against the housing to secure the second element in said positions.

Preferably the nut tightens against the housing through an intermediate member which is shaped to match the housing.

Preferably the second element carries at its surface-engaging end a foot which is pivotally mounted to the second element.

The pivotable mounting is preferably universally pivotable. In a preferred embodiment the foot has a domed upper surface and the second element has a cup-shaped lower surface arranged to bear against the domed surface in use.

The shape of the cup-shaped lower surface preferably conforms to that of the domed upper surface to spread the weight of the structure being supported evenly. Preferably a stem projects from the main part and enters an aperture in the domed surface of the foot and is retained therein. Suitably a bulbous head on the stem is retained behind a portion of the aperture of restricted diameter, and the bulbous head and restricted portion provide the pivot point for the foot.

If the aperture extends through the foot to a side thereof remote from the domed surface and is of substantially greater diameter than the stem, relative movement of the foot and the stem causes any debris entrapped in the region of the aperture to fall through the aperture and out from said remote side.

An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings, wherein: Figure 1 is a partially exploded perspective view of a supporting device, Figure 2 shows two such devices in use on a ladder, Figure 3 is a plan view from below of a foot for the device of Figure 1, and Figure 4 is a cross-section on an enlarged scale along the line A-A in Figure 3.

Referring firstly to Figure 1; the supporting device comprises a generally tubular housing 10 in which slides a bar 12 which protrudes from either end of the housing. The housing 10 has a longitudinal slot 30 in which runs a locating member 16 which is secured transversely to the bar 12. The slot 30 has transverse recesses 32 cut out from the housing 10, the recesses 32 being in staggered relationship on either side of the slot 30.

The locating member 16 fits into one of these transverse recesses in order to locate the bar 12 at a given vertical position in the housing 10. The locating member is screwthreaded, and to clamp the bar in that given position, a wing nut 34 is screwed onto the locating member 16 to tighten an intermediate shroud 36 against the housing. The shroud 36 has a hole 38 to receive the locating member 16, and is arcuate in shape and mates with the tubular housing 10 to ensure secure clamping. Obviously, the shroud could be dispensed with if desired and the wing nut tightened directly against the housing 10. The housing includes two securing plates 20 which are drilled at 22 to receive screws to secure the housing to a structure to be supported, for example to a stile of a ladder or to scaffolding. Other securing means, e.g. bolts or welding, could be used.

Figure 2 shows two such devices in use, secured to end portions of respective stiles 40 of a ladder. The ladder can be supported in a stable position on a non-level surface 42 by location of the bar 12 of each supporting device in a suitable position in its housing 10, so that the two supporting devices form respective legs for the ladder which are of differing lengths to compensate for the unevenness of the surface 42. Where the devices are being attached to ladders having channel-section metal stiles, it will often be desirable to fit wooden blocks on the side of each stile remote from the device to receive the fixing screws passing through the holes 22.The devices can be fixed to the outsides of the stiles if desired, but a neater and more convenient arrangement is produced if they are fitted to the insides of the stiles, and they should therefore be made of a size which will fit between the bottom of the stiles and the lowest rung of the ladder. It will be appreciated that in simple ladders a supporting device need only be fitted to one stile, since by merely turning the ladder around it can be supported in a stable position on a surface which slopes in any direction. However this is not possible with extending ladders, so it will normally then be necessary to fit two devices as shown in Figure 2.

It will be appreciated that in use the locating member 16 bears against the upper edge 44 of the recess 32 in which it is located.

To ensure positive engagement of the locating member, each recess 32 (and in particular each upper edge 44) is angled slightly upwardly away from the slot 30. The locating member 16 is thus retained in its recess 32 in use by the load which it is supporting.

The supporting device shown in Figure 1 has a foot 46 which is mounted to the bar 12 by a universal pivot which as can be seen in Figure 2 ensures that the entire lower surface of the foot bears on the non-level surface 42. The foot is shown in more detail in Figures 3 and 4 and has a moulding 48 of rubber or plastics material which provides aslip-resistant lower surface 50 for the foot.

Channels 52 in the lower surface 50 lead away water when the device is used in wet conditions, and enhance the slip-resistant properties of the foot.

A metal plate 54 is bonded to the moulding 48 and provides a domed upper surface 56 for the foot. A cup-shaped collar 58 is provided on the lower end of the bar 12, and the lower surface 60 of this collar conforms to the shape of the domed surface 56 and bears against that surface in use.

Where the moulding 48 is of plastics material, the domed surface 56 can be formed as part of the moulding, without a separate plate 54.

A stem 62 projects downwardly from the end of the bar 12 into an aperture 64 extending through the moulding 48. The stem 62 has a bulbous head 66 which is retained in the aperture 64 by a portion 68 thereof having a restricted diameter. The portion 68 may have a wire ring 70 integral with the moulding 48 to retain its shape if necessary. The stem 62 and the head 66 are a loose fit in the aperture 64 and the restricted portion 68, but the mouth of the aperture 64 is conically flared at 72 and the bulbous head 66 is somewhat rounded so that the stem 62 can pivot universally with respect to the portion 68. Because the head 66 is retained only loosely in the aperture 64, the cup-shaped surface 60 is likewise a loose fit on the dome-shaped surface 56.Because of the loose fits and because the aperture 64 is open at the bottom, any foreign debris entrapped in the aperture 64 or between the surfaces 56, 60 will fall through the aperture on shaking the device.

The foot 46, with the collar 58, stem 62 and head 66, is secured to the bar 12 by screwing it into a screw-threaded hole 74 therein. Thus, the foot 46 can be replaced by a foot of alternative design if required for a particular application.

The supporting device will be fixed to a ladder or other structure in such a manner that the stile of the ladder in normal use lies to the right of the line X-Y in Figure 4.

Advantageously it is mounted on the stile in such a manner that when the bar 12 is fully retracted into the housing 10 (the foot 46 being pivoted away from the stile to achieve this), the stile lies to the right of line Y-Z in Figure 4, and the foot does not protrude below the bottom of the stile. The foot 46 is thus neatly housed inside the stile and the ladder can be used normally without the supporting device, if required.

The supporting device described is adjustable only manually, but adjustment could be effected by pneumatic, electrical or hydraulic means if desired.

WHAT I CLAIM IS: 1. A structure having a device for supporting the structure on a surface, said device comprising a housing rigidly attached to the structure and an elongate second element slidable longitudinally with respect to the housing into one of a plurality of spaced positions which are arranged such that in use the second element forms a variable length leg for engaging with the surface, the housing having a slot therein which is longitudinal with respect to the second element, the second element having a locating member which runs in said slot when the second member slides in the housing, and wherein the slot has transverse recesses to engage the locating member in said positions.

2. A structure according to claim 1 wherein each transverse recess has an edge remote from the surface-engaging end of the second element which rises upwardly away from the slot to provide positive location for the locating member.

3. A structure according to claim 1 or claim 2 wherein the locating member is screw-threaded and receives a nut which tightens directly or indirectly against the housing to secure the second element in said positions.

4. A structure according to claim 3 wherein the nut tightens against the housing through an intermediate member which is shaped to match the housing.

5. A structure according to any one of the preceding claims wherein the second element carries at its surface-engaging end a foot which is pivotally mounted to the second element.

6. A structure according to claim 5 wherein the first element is attached or attachable to a surface of the structure which is generally parallel to the leg formed by the second element, the foot projecting laterally beyond said surface in an operative extended condition of the leg, and being pivotable to lie wholly to one side of said surface in an inoperative retracted condition of the leg.

7. A structure according to claim 5 or claim 6 wherein the pivotable mounting is universally pivotable.

8. A structure according to claim 7 wherein the foot has a domed upper surface and the second element has a cup-shaped lower surface arranged to bear against the domed surface in use.

9. A structure according to claim 8 wherein the shape of the cup-shaped lower surface conforms to the shape of the domed upper surface.

10. A structure according to claim 8 or claim 9 wherein a stem projects from the cup-shaped lower surtace and enters an aperture in the domed surface of the foot and is retained therein.

11. A structure according to claim 10 wherein a bulbous head on the stem is retained behind a portion of the aperture of restricted diameter, and the bulbous head and restricted portion provide the pivot point for the foot.

12. A structure according to claim 10 or claim 11 wherein the aperture extends through the foot to a side thereof remote from the domed surface and is of substantially greater diameter than the stem, whereby movement of the foot relative to the stem causes any debris entrapped in the region of the aperture to fall through the aperture and out from said remote side.

13. A structure having a supporting device as described herein with reference to Figure 1, or Figure 1 together with Figures 3 and 4, of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (13)

**WARNING** start of CLMS field may overlap end of DESC **. The supporting device described is adjustable only manually, but adjustment could be effected by pneumatic, electrical or hydraulic means if desired. WHAT I CLAIM IS:

1. A structure having a device for supporting the structure on a surface, said device comprising a housing rigidly attached to the structure and an elongate second element slidable longitudinally with respect to the housing into one of a plurality of spaced positions which are arranged such that in use the second element forms a variable length leg for engaging with the surface, the housing having a slot therein which is longitudinal with respect to the second element, the second element having a locating member which runs in said slot when the second member slides in the housing, and wherein the slot has transverse recesses to engage the locating member in said positions.

2. A structure according to claim 1 wherein each transverse recess has an edge remote from the surface-engaging end of the second element which rises upwardly away from the slot to provide positive location for the locating member.

3. A structure according to claim 1 or claim 2 wherein the locating member is screw-threaded and receives a nut which tightens directly or indirectly against the housing to secure the second element in said positions.

4. A structure according to claim 3 wherein the nut tightens against the housing through an intermediate member which is shaped to match the housing.

5. A structure according to any one of the preceding claims wherein the second element carries at its surface-engaging end a foot which is pivotally mounted to the second element.

6. A structure according to claim 5 wherein the first element is attached or attachable to a surface of the structure which is generally parallel to the leg formed by the second element, the foot projecting laterally beyond said surface in an operative extended condition of the leg, and being pivotable to lie wholly to one side of said surface in an inoperative retracted condition of the leg.

7. A structure according to claim 5 or claim 6 wherein the pivotable mounting is universally pivotable.

8. A structure according to claim 7 wherein the foot has a domed upper surface and the second element has a cup-shaped lower surface arranged to bear against the domed surface in use.

9. A structure according to claim 8 wherein the shape of the cup-shaped lower surface conforms to the shape of the domed upper surface.

10. A structure according to claim 8 or claim 9 wherein a stem projects from the cup-shaped lower surtace and enters an aperture in the domed surface of the foot and is retained therein.

11. A structure according to claim 10 wherein a bulbous head on the stem is retained behind a portion of the aperture of restricted diameter, and the bulbous head and restricted portion provide the pivot point for the foot.

12. A structure according to claim 10 or claim 11 wherein the aperture extends through the foot to a side thereof remote from the domed surface and is of substantially greater diameter than the stem, whereby movement of the foot relative to the stem causes any debris entrapped in the region of the aperture to fall through the aperture and out from said remote side.

13. A structure having a supporting device as described herein with reference to Figure 1, or Figure 1 together with Figures 3 and 4, of the accompanying drawings.