GB2456630A

GB2456630A - Roofer's ladder for use on a hip roof or roof valley

Info

Publication number: GB2456630A
Application number: GB0900733A
Authority: GB
Inventors: Gary Skrzypkowski
Original assignee: CHINA TECHNOLOGY Ltd
Current assignee: CHINA TECHNOLOGY Ltd
Priority date: 2008-01-16
Filing date: 2009-01-16
Publication date: 2009-07-22
Also published as: GB0900733D0; GB0800686D0

Abstract

A roofer's ladder with a pair of side members 10, 11 and a plurality of treads or rungs 12 hinged to the side members to form a parallelogram linkage. There may be one or more locking devices 15 which may take the form of variable length members, which may be telescopic, screw threaded, pneumatic, hydraulic or have a rack and pinion and may fit into a slot in the ladder. Alternatively the locking mechanism may take the form of pin engaging in a part circular plate. There may also be support hooks fitted to the top 13 and/or the sides 14 to secure the ladder to the roof ridge or hip ridge of the roof. These hooks may be extendable and rotatable and could also be used as spacers.

Description

2456630

- 1 -

• • • • •

• ••I

• • • •

• • • • • • • • • ••• • • • •

• • »• •

• •••

«

• • • •

ROOFER'S LADDER

This invention relates to an improved roofer's ladder, particularly for use on hip or valley roofs, where a tiled or slated roof area is bounded by an inclined edge.

Hip roofs are frequently encountered in the design of standard British semi-5 detached dwelling houses, to provide a gable-free construction with inclined edges where slopping roof surfaces meet in a half-pyramid configuration. Many other roofs feature valleys, between a main roof and a wing or dormer roof.

Standard roofer's ladders comprise a simple construction of two parallel side rails, and a plurality of treads or rungs extending between the rails. Hooks extend 10 from the top ends of the side rails to engage over the ridge of the roof, so that the ladder can be securely held with the rails flat against the sloping roof, so that a roofing worker can safely climb up the ladder, and work on slates or tiles to either side of the ladder.

A problem arises say with hip roofs, in that a considerable area of the roof is 15 not safely accessible from a straight ladder hooked over the roof ridge. The alternatives to date have been to try to reach as far as possible from a straight ladder, which has obvious dangers, or to work from ground based ladders at maximum extension, perhaps bracing the feet of a further ladder on the upper ends of a ground based ladder, which has the danger that the further ladder may tend to push the top of 20 the ground based ladder away from its support on the eaves of the roof. All these unsatisfactory arrangements arise because it is not possible to safely slant a roof ladder, because the slanted treads provide an insecure foothold, or hook it over the hip ridge, as the hooks cannot be securely located on the hip ridge.

It is an object of the invention accordingly to provide a ladder which can be securely supported from the roof ridge, yet be slanted to enable access into the hip roof area.

The invention provides a roofer's ladder which comprises two parallel side rails and a plurality of mutually parallel treads, the treads extending between the side rails and each being articulated at each end to each rail, whereby the treads and side rails comprise a parallelogram linkage which can be adjusted in inclination whilst keeping the side rails and the treads in respectively parallel relationships.

Advantageously, the ladder preferably also comprises means whereby the linkage may be locked into one or more desired positions of inclination.

The locking means may comprise one or more members of variable length which each extend either between respective pairs of treads, or the side rails.

Preferably one end of the locking means is fixed in position on one of the treads, or side rails, and the other end is preferably adjustable in position along the other of the pair of treads or the other side rail.

The fixed end of the locking means may be mounted so that the variable length member extends substantially at right angles to the tread or side rail on which it is mounted. This fixed end is preferably mounted half way along the respective tread, or on the side rail half way between adjacent treads, to afford an equal range of movement to the other end of the variable length member in each direction along the other tread of the pair, or the other side rail.

The variable length member may comprise a telescopic strut, having a smaller diameter piece slidably received in a larger diameter piece, and securable in a range of selectable positions by a pin or equivalent detent engaging through alignable holes on

the smaller and larger diameter pieces. In an alternative embodiment, the variable length member may comprise a screw threaded shaft which can be turned by a knob to rotate through a threaded collar to thereby retract or extend the shaft.

Possible alternatives include a rack and pinion device, or a pneumatic or hydraulic jack. The movable end of the variable length member may be for example received on a slot associated with the tread or side rail, and retained in position for example by a pin which engages in a selected hole, or rack member or the like.

An alternative and preferred locking means comprises a part circular plate or disc, secured to one side rail of the ladder, and having a series of holes near the periphery for engagement with a pin passed through a tread, so that the ladder can be retained in a range of slanted positions. Two or more such locking means may be provided along the length of the ladder.

The ladder preferably also has hooks which extend from an upper tread or cross member to engage over a roof ridge, to support the ladder, and additionally support hooks may be provided on one, or each of the side rails for engaging with a hip ridge to further secure the ladder in a selected use position. The hooks may be extensible to vary the slope and spacing of the ladder from the hip ridge, and comprise an end part which can be rotated between a position wherein the hooks can engage over a hip roof ridge, and an alternative position wherein the ends thereof rest on a roof part extending at an angle to the roof on which the ladder rests, in a roof valley.

An embodiment of roofer's ladder according to the invention will now be described by way of example, with reference to the accompanying drawings,

Figure 1 is a general view of a roofer's ladder according to the invention, in a normal, straight, position;

Figure 2 is a detailed view of an upper end of the ladder, in a slanted position; Figure 3 is a view of the ladder in use on a hip roof, slanted for working in the hip area of the roof; and Figure 4 is a fragmentary view showing an alternative latching mechanism. Figure 5 is a fragmentary view of a retaining member; and Figure 6 is a perspective view of the ladder as adapted for use in a valley of a roof structure.

A roofer's ladder according to the invention, as shown in the drawings, comprises a pair of parallel side rails 10, 11, with a plurality of treads 12 extending therebetween, and each tread 12 is pivotally connected by a respective pivot connection 13 at both ends to the respective side rails 10, 11. The side rails 10, 11 and the treads 12 form a parallelogram linkage so that the side rails 10, 11 are always parallel to each other, and the treads 12 are always parallel to each other, irrespective of the angle between the side rails and the treads. The result of this is that the treads 12 can always be horizontally whatever the angle of slant at which the ladder is laid on a roof, and also the ladder can be laid with any slant angle required, for example to match the slope of a hip roof ridge, as in Figure 3, whilst the treads remain horizontal and thus safe as a work platform.

The ladder is also provided with roof hooks 13, which are connected to the uppermost tread 12, and as in Figure 3 can be hooked over a roof ridge, to retain the ladder in use. Spaced apart support hooks 14 are also provided to connect the side rails to a retaining structure such as sloping hip ridge as in Figure 3 again. These are

provided on both side rails 10, 11 so that the ladder can be secured to either the right or the left hand sides. The hooks 13, 14 are extensible to vary the spacing and slope of the ladder from the hip ridge.

To ensure safety it is also required in accordance with the invention to retain the ladder in its selected slanted position, that is retain the required inclination angles between the side rails 10, 11 and the treads 12 and this is achieved by a locking mechanism 15. This comprises a telescopic strut which is anchored at one end to the side rail 10 and has its other end slidable in a slot 16 in the other side rail 11. The strut comprises a larger diameter part 17 and a smaller diameter part 18 which is slidable into and out of the larger diameter part 17 and the selected position may be maintained by means of a pin in one of a series of pin holes 19 in the smaller diameter part 18. The slidable end of the strut, in the slot 16 may be held by a tightenable screw with a wingnut 20.

An alternative position for the locking mechanism 15 is extending between two adjacent treads, as shown in broken lines in Figure 2 at 15a, with the movable end received in a slot 16a in one tread 12 and also shown in broken lines. Such struts 15 on 15a may be provided near the top and bottom of the ladder.

Figure 4 shows an alternative, and preferred, embodiment of latching mechanism for latching the ladder to retain it in any selected one of a range of slanted positions, from vertical to an extreme slant to either side. The latching mechanism comprises associated with each of say two or three selected treads 12, spaced at intervals up the ladder, is provided a half circular disc 16 mounted securely on one of the ladder side members 10. The disc 16 is provided towards its periphery with a series of apertures or pin holes 17, defining a plurality of angular positions which can

• •• • • • •

• • I

• ••#

• • • • • •

t •• • •

• • • •

• •• • • • • ••• • ••• • • • •••

-6-

be subtended between the tread 12 and the side member 10. A securing pin 17, which can pass through an appropriately located hole in the tread 12 is used to secure the tread 12 in position relative to the disc 16 and thereby retain the ladder in a selected slant position.

5 Figure 5 shows a fragmentary view of one of the side hooks 14, the others being similar. The hook comprises a main part 14 connected to the ladder, and an extensible part 14a which is both slidable and rotatable in an end of part 14, so as to permit adjustment of length, and position of the part 14a, which carries a hook part 14c shaped to alternatively hook over the ridge tiles of a hip roof, or rest on a roof 10 adjoining the roof part on which the ladder rests, in a roof valley.

In use, in a first position of rotation, the hooks 13 may be engaged over a horizontal roof ridge, and the ladder then adjusted in its inclination to enable access to the required area in a hip roof area, either as in Figure 3, or in some intermediate position. The slanted ladder is secured in its position by adjustment and locking of 15 the struts 15 at top and bottom, and can be safely used to gain access to the areas of the roof not easy to gain safe access to using vertical ridge ladders, or by ladders supported from below.

Figure 6 shows a roof valley where a dormer roof 21 joins a main roof 22. The ladder is rested on the main roof, and the end parts 14a, 14c of the hooks 14 are 20 rotated so that the ends 23 of the hooks 14c rest on the dormer roof, to support the ladder against sideways displacement.

Variations may be made within the scope of the invention to the shapes and configurations and dispositions of the hooks and of the locking devices.

Claims

A roofer's ladder comprising two parallel side rails and a plurality of mutually parallel treads, the treads extending between the side rails and each being articulated at each end to each rail, whereby the treads and side rails comprise a parallelogram linkage which can be adjusted in inclination whilst keeping the side rails and the treads in respective parallel relationships.

A ladder according to Claim 1, wherein the ladder also comprises locking means whereby the linkage may be locked into one or more desired positions of inclination.

A ladder according to Claim 2, wherein the locking means comprises one or more members of variable length which each extend between respective pairs of treads, or the side rails.

A ladder according to Claim 3, wherein one end of the locking means is fixed in position in one of the treads or side rails, and the other end is adjustable in position along the other of the pair of treads, or the other side rail.

A ladder according to Claim 4, wherein a fixed end of the locking means is mounted so that the variable length member extends substantially at right angles to the tread or side rail on which it is moulded.

A ladder according to Claim 5, wherein the fixed end is mounted half-way along the respective tread or on the side-rail half way between adjacent treads, to afford an equal range of movement to the other end of the variable

length member in each direction along the other tread of the pair, or the other side rail.

A ladder according to any one of Claims 3 to 6, wherein the variable length member comprises a telescopic strut having a smaller diameter piece slidably received in a long diameter piece, and securable in a range of selectable positions by a pin or equivalent detent engaging through aligned holes in the smaller and longer diameter pieces.

A ladder according to any one of Claims 3 to 6 wherein the variable length member comprises a screw-threaded shaft which can be turned by a knob to rotate through a threaded collar to thereby retract or expand the shaft. A ladder according any one of Claims 3 to 6 wherein the variable length member comprises a rack and pinion device, or a pneumatic or hydraulic jack.

A ladder according to Claim 7, 8 or 9 wherein the movable end of the variable length member is received in a slot associated with a tread or a side rail, and retained in position by a pin which engages in a selected hole, rack member or the like.

A ladder according to Claim 2 wherein the locking means comprises a part-circular plate or disc, secured to one side rail of the ladder, and having a series of holes near the periphery for engagement with a pin passed through a tread, so that the ladder can be retained in any of a range of slanted positions.

A ladder according to Claim 10 wherein two or more such locking means are provided along the length of the ladder.

-9-

13. A ladder according to any preceding claim, wherein the ladder has hooks which extend from an upper tread or cross-member to engage over a roof ridge to support the ladder.

14. A ladder according to Claim 13 wherein support hooks provided on one or 5 each of the side rails for engaging with a hip ridge to further secure the ladder in a selected use position.

15. A ladder according to Claim 14 wherein the hooks are extensible to vary the slope and spacing of the ladder from the hip ridge.

16. A ladder according to claim 15 wherein the hooks are rotatable to an

10 alternative position to enable the hooks to act as spacer members which have ends which enable the ladder to be placed in a valet between a main roof part and a wing or dormer roof, the ends resting on the other of the roof parts to that upon which the ladder rests.

17 A roofer's ladder, substantially as hereinbefore described, with reference to 15 and as illustrated in the accompanying drawings.

• •• • • • • » • • •••

•

• • • •• »•••

4

♦ ••• • « • • • •

• •• • ••••