GB2235236A

GB2235236A - Ladder tread threaded by stiles

Info

Publication number: GB2235236A
Application number: GB9015579A
Authority: GB
Inventors: Terence Humphreys
Original assignee: LEW WAYS Ltd
Current assignee: LEW WAYS Ltd
Priority date: 1989-08-19
Filing date: 1990-07-16
Publication date: 1991-02-27
Anticipated expiration: 2010-07-16
Also published as: GB8918950D0; GB9015579D0; GB2235236B

Abstract

A ladder comprises a pair of stiles and a series of treads made as plastics mouldings, each tread being apertured at each end to be threaded by the stile, and being fixed in position relative to the stiles. <IMAGE>

Description

LADDERS This invention relates to ladders and includes within its scope such similar constructions as steps, stepstools and the like. Our prior patent application EW 2185775A proposes a ladder having two stiles, a rung extendinc therebetween and a tread located adjacent the rung, which is characterised in that the tread comprises a plastics moulding having aligned recesses at respective ends to receive the respective stiles in engagement therein, the underside of the tread being in load bearing engagement with the rung, the tread being assembled to the ladder as a wedge fit or snap fit.Such an arranccment offers substantial advantages over the prior art in reducing manufacturing costs whilst provided 2 ladder which is satisfactory for use n domestic situations or for example by children.

The object of the present invention is to provide further improvements.

According to the present invention, a ladder comprises a pair of stiles and at least one tread which is apertured at both ends, the apertures being threaded by the stiles, and the tread being fixed in position relative to the stiles.

The invention is now more particularly describe.

with reference to the accompanying drains wherein: Figure 1 is a part-sectional fragmentary elevation of a ladder: Figure 2 is a type plan view of the same: Figure 3 is an underneath plan view: and Figure 4 is a view similar to Figure 1, showing a modification.

referring no to the dra-wins, particularly figures 1-3 thereof, the ladder comprises a pair of stiles, here shown as lengths of steel tube 10, 12. Each tread comprises a plastics ciouldinc including a wide upper generally flat (possibly patterned so as to 5e non-sliF) face 14 forming the tread per se, and a pair of sockets.

one at each end of the tread, extending through vertically elongated bosses 16. The underside of the tread is reinforced by a system of webs 1z.

The bosses 16 niay be inclined at an angle different than 90 deg. to the tread, so that when the ladder is in the intended position for use at the intended inclination to the vertical, the treads are then horizontal.

The treads are to be secured at the required vertical spacing upon the stiles, and preferably are fixed in position to the stiles. Figure 1 illustrates this diagrammatically by showing abutment rings 18 fixed to the stiles by grub screws 20. Alternatively cotter pins could be passed through diametrically aligned holes in the stiles to support the abutment rings and the tread simply rests upon these. A more permanent fixing together of all of the components against unintentional displacement is preferred. It would be possible to weld the rings or equivalent abutments in place and snapengage the treads with those welded rings.

However, taking into account the desired paint finish for steel tube, and the requirements for volume production in factory conditions, the presently preferred embodiment is shown in Figure 4 where the ladder is provided with steel tube rungs 24 with flattened ends, fixed to the stiles by bolts 2. This allows the stiles and rungs to have the appropriate paint or other finish applied, and then assembled using the bolts to fix the rungs in place, and as each rung is assembled, a tread is slid along the stiles into position and snap-encaged with the rung. The tread then provides additional angular fixing preventing the parts assuming a parallelogram shape and maintaining then square. This is accomplished by the sockets being a relatively close fit upon the stiles, and by the tread bein a close fit to the rung.

Conveniently the tread has a channel on its underside to receive the rung, and the channel may be of complementary cross section to the rung. If the rung is of circular tube, which is the simpler and preferred case, the channel may be generally semi-circular but extend over more than a 12G deg. of arc, and the inherent flexibility and resilience of plastics materials suitable for moulding to make the treads will enable the rungs to be snap-enaged by the tread.

In other un-illustrated embodiments the treads are fixed to a rungless ladder provided with abutments by any convenient means.

The invention provides a ladder construction which is simple to manufacture and particularly economic to assemble.

Claims

CLP.ITi;S

1. R ladder comprising a pair of stiles and at least one tread hich is apertured at both ends, the apertures being threaded by the stiles, and the tread being fixed in position relative to the stiles.

2. A ladder as claimed in Claim 1 in which the tread is fixed to the stiles themselves.

3. h ladder as claimed in Claim 1 in which a series of rungs are provided and the treads are fixed to the rungs.

4. A ladder as claimed in any of Claims 1 to 3 wherein abutments are provided on the stiles and the tread is fixed to the abutments.

5. A ladder as claimed in Claim 1 comprising at least one rung extending between said stiles in which the tread is supported on the rung.

6. A ladder as claimed in Claim in which the abutments or rungs are detachably connected to the stiles.

7. A ladder as claimed in any preceding claim wherein the tread is a plastics moulding having a wide portion to act as the step per se and vertically extending bosses at each end provided with through bores forming sockets and through which the stiles extend.

10. P ladder substantially as hereinbefore described and with reference to and as shown in the accompanying drawings.