GB2473961A

GB2473961A - A folding ladder

Info

Publication number: GB2473961A
Application number: GB1016202A
Authority: GB
Inventors: Charles Woods
Original assignee: FIRE ESCAPES
Current assignee: FIRE ESCAPES
Priority date: 2009-09-28
Filing date: 2010-09-27
Publication date: 2011-03-30
Also published as: GB0916950D0; GB201016202D0; EP2305945A1

Abstract

A collapsible ladder includes a pair of stiles 20, and rungs 21 pivotally connected to the stiles in such manner that the ladder is movable between a folded, storage condition, in which the stiles cooperate to define a chamber within which the rungs are contained, and an unfolded condition in which the rungs extend horizontally. A cap (11, fig 4) is provided for fitment over the upper ends of the stiles to hold them together in the folded, storage condition. Cover formations 14 are formed integrally with the stiles, and are arranged to inter-engage when the ladder is in its folded condition to prevent access to the rungs and stiles and hence tampering or damage to the ladder. The ladder may be used with a multi-storey building. In further aspects a folding ladder is provided with a chamfered cap or a security device for preventing unauthorized removal of the cap.

Description

FOLDING LADDERS

Field of the Invention

This invention relates to folding ladders.

In British Patent Specification No. 2 363 156 there is described a folding ladder which includes a pair of elongated stiles, a plurality of rungs pivotally connected to the stiles in such manner that the ladder is movable between a folded, storage condition, in which the stiles cooperate with one another to define a chamber within which the rungs are contained, and an unfolded condition in which the rungs extend horizontally, a cap for fitment over the upper ends of the stiles to hold them in contact with one another in the folded, storage condition, and cover formations carried by the stiles, the cover formations being arranged to interengage when the ladder is in its folded, storage condition to prevent access to the rungs and stiles and hence tampering of, and damage to, the rungs and stiles.

The cover formations are of generally semi-cylindrical configuration and spring clip means are provided at the lower end of one of the stiles for engagement with the other stile to restrain the lower ends of the stiles from separation when the ladder is in its folded, storage condition.

It is an object of the present invention to provide improvements in and modifications of the folding ladder referred to above.

A folding ladder which includes a pair of elongated stiles, a plurality of rungs pivotally connected to the stiles in such manner that the ladder is movable between a folded, storage condition, in which the stiles cooperate with one another to define a chamber within which the rungs are contained, and an unfolded condition in which the rungs extend horizontally, and a cap for fitment over the upper ends of the stiles to hold them in contact with one another in the folded, storage condition is hereinafter referred to as "a folding ladder as defined".

It is a more specific object of the present invention to provide an improved form of folding ladder as defined.

Summary of the Invention

According to a first aspect of the present invention there is provided a folding ladder which includes a pair of elongated stiles, a plurality of rungs pivotally connected to the stiles in such manner that the ladder is movable between a folded, storage condition, in which the stiles cooperate with one another to define a chamber within which the rungs are contained, and an unfolded condition in which the rungs extend horizontally, a cap for fitment over the upper ends of the stiles to hold them in contact with one another in the folded, storage condition, and cover formations formed integrally with the stiles, the cover formations being arranged to interengage when the ladder is in its folded, storage condition to prevent access to the rungs and stiles and hence tampering of, and damage to, the rungs and stiles.

According to a second aspect of the present invention there is provided a folding ladder as defined in which the lower edge of the cap is chamfered.

According to a third aspect of the present invention there is provided a folding ladder as defined which includes a security device for preventing unauthorized removal of the cap.

The security device preferably has a snap-fit engagement with the upper ends of the stiles.

According to a further aspect of the present invention there is provided a folding ladder as defined in which the cap includes a handle for facilitating authorized removal thereof.

According to another aspect of the present invention there is provided a folding ladder as defined which includes brackets for fixing the ladder to a host wall, the brackets having curved support surfaces engaged by the stiles, the curved support surfaces being formed with slots to receive fixing bolts.

According to another aspect of the present invention there is provided a folding ladder having the features set out above which is formed as two or more sections which, in use, are disposed one above another and which includes an intermediate release device permitting opening of a lower ladder section independently of an upper ladder section.

Brief Description of the Drawings

Figure 1 is a plan view of a cap fitted to the top of a folding ladder, Figure 2 is a sectional view showing the cap fitted to the top of the ladder, Figure 3 is a plan view of a security device fitted to the top of the ladder, Figure 4 is a sectional view showing the security device in use, Figure 5 is a schematic view showing adjustment of the angle of the ladder to the host wall, Figures 6 and 7 show the configuration of the bracket used to attach the ladder to the host wall, Figures 8 and 9 illustrate the cross-sectional configuration of the outer casing of the ladder, and Figures 10, 11 and 12 show the use of an intermediate release device used to join together an upper ladder and a lower ladder.

Description of the Preferred Embodiments

The top cap/release mechanism of British Patent Specification No. 2 363 156 not only allows the ladder to open when removed but prevents the ingress of water and dirt, helping keep the rungs and moving/hinging connections clean and dry so that usage is safer when required. Although the cap is usually a minimum of 4.5 m above ground there is a perception that it can be pushed off from below allowing the ladder to open and perhaps be used to gain entry to the upper window of a building The new top cap design shown in Figures 1 and 2 has two features not included in the top cap design of British Patent

Specification No. 2 363 156:-

(a) There is a handle 10 which is semi-circular in shape moulded or fitted to the top surface of the cap 11 to help children (with smaller hands) or elderly or arthritic people remove the cap 11 when required. The handle 10 gives the facility to open/ pull off the cap 11 without an outstretched hand ensuring that anyone can use the product.

(b) The bottom outer edges 12 of the cap 11 have been chamfered / feathered to eliminate the existing square edge. This would tend to deflect an object such as a long rod which could potentially be used to push off the cap 11.

The improved ladder design can include a security device shown in Figures 3 and 4 that is in the form of a component 13 which is designed to prevent the top cap 11 being pushed off from below. The device is a moulded or formed component which is fitted over the top edges of the ladder outer casings 14. It takes the form of a sleeve fit with the outer side having a chamfered I feathered edge 15 to deflect any object being used in an attempt to push the top cap off from below. The inner section of the sleeve-like component 13 has multiple (probably four) raised sections 16 at the bottom edge which snap into holes formed in the outer ladder casings 14. These snap-in sections 16 prevent the component 13 (security device) being pushed or pulled off the top of the ladder.

The top cap 11 of Figures 1 and 2, when used with the security device 13, has the feathered bottom edges removed to allow the cap 10 to fit down onto a shoulder in the security device.

This design prevents the top cap 11 being removed from below such that it can only be pulled off upwards from above.

The security device 13 has the added benefit of placing a moulded plastic (or other material) component which has no sharp edges at the top of the ladder thereby covering the top surfaces of the ladder which could potentially cause injury such as a cut, by nature of their shape and material used (usually aluminium) A bracket 17 (the configuration of which is shown in Figures 6 and 7 and which is shown in use in Figure 5) is cut from an aluminium extrusion and is then drilled or slotted to receive ladder bolt connections and to allow fixings to the host building.

The bracket 17 is curved to follow the outer casing 14 of the ladder thereby ensuring a solid connection which also prevents the ladder from twisting when in use. A horizontal slot 18 in the bracket is to receive the connecting bolt 19 from the ladder and allows the ladder to pivot 13° either side of a 900 angle to the host building.

The purpose of the pivot facility is to allow the ladder to possibly avoid an obstruction but also effectively gives more shoulder room for the user when in the pivot position by angling the user away from the host wall 20. Brackets 17 can be fitted at irregular spacings on the ladder (if required to facilitate better fixings to the host wall) as the bolt heads do not foul the operation of the folded rungs.

The ladder design of British Patent Specification No. 2 363 156 (to which reference should be made) has the strings and outer casings as separate components effectively meaning that the ladder might be manufactured and used without the need for outer casings. The outer casings not only make the ladder look like a rain water pipe and therefore unobtrusive but, more importantly, they cover the strings / rungs I bolts etc. keeping them out of sight from potential vandalism I tampering and also keeping the moving parts i.e. rungs, etc. clean and dry for safe use when required.

The ladder design of the present invention combines the outer casings 14 and strings 20 into one extrusion (as shown in Figures 8 and 9) and this prevents the ladder being manufactured or used without the protection offered by the outer casings 14. The detailed shaping of the strings 20 and the manner in which they interengage is shown in Figure 8. Forming the outer casings 14 integrally with the strings 20 also reduces the number of components from the previous four extrusions down to one extrusion, as shown in Figure 9, which is used for the strings, the rungs 21 forming the hinging mechanism. Substantial cost savings can thus be achieved.

The ladder design of the present invention also incorporates extruded slots to hold the heads of the bolts used for fixing to the brackets in such a way as to prevent them spinning or turning when tightening the nuts on the fixing bracket bolts. The recessed bracket bolt head positions of the present invention now allow the rungs to be folded closed without fouling on the bolt heads. This in turn allows the rungs to be 50 mm wider and the brackets can be fitted in any position needed e.g. to be moved up or down on a host wall to achieve better fixing without consideration of rung closing. There are similar extruded slots where the bolt heads for fixing the rungs are used. This prevents rotation in the same way as the bracket bolts.

As indicated in Figure 9, there is a "V" guide in the outer casing 14 to locate the drill bit when drilling holes to receive the bolts 19 used for attachment of the outer casing 14 to the brackets 17.

Where two or more ladders were placed one above the other, the ladder design of British Patent Specification No. 2 363 156 had no facility to open the ladder at intermediate positions i.e. where a ground floor ladder meets the second floor and so on.

The reason why this facility is needed is to allow opening of the lower ladder without necessarily opening the one above e.g. for use in multi-storey buildings I flats etc. The ladder design of the present invention allows opening of the lower ladder in isolation or, if at second floor level, enables the user to open the bottom two ladders and the ones above remain closed and so on.

Figures 10, 11 and 12 show the provision of an intermediate release device, which is used to connect an upper ladder section to a lower ladder section 21. The release device comprises a pair of blocks 22 and 23, with one block 22 being connected to the bottom of the upper ladder section 20 and the other block 23 connected to the top of the lower ladder section 21. A stainless stee' pin 24 fits in aligned bores in the two blocks 22 and 23 to hold the two ladder sections 20 and 21 against movement relative to one another and is removable by pulling on a pull ring 25 attached to the pin 24.

Claims

Claims:- 1. A folding ladder which includes a pair of elongated stiles, a plurality of rungs pivotally connected to the stiles in such manner that the ladder is movable between a folded, storage condition, in which the stiles cooperate with one another to define a chamber within which the rungs are contained, and an unfolded condition in which the rungs extend horizontally, a cap for fitment over the upper ends of the stiles to hold them in contact with one another in the folded, storage condition, and cover formations formed integrally with the stiles, the cover formations being arranged to interengage when the ladder is in its folded, storage condition to prevent access to the rungs and stiles and hence tampering of, and damage to, the rungs and stiles.
2. A folding ladder as claimed in Claim 1, in which the lower edge of the cap is chamfered.
3. A folding ladder as claimed in either of the preceding claims, which includes a security device for preventing unauthorized removal of the cap.
4. A folding ladder as claimed in Claim 3, in which the security device has a snap-fit engagement with the upper ends of the stiles.
5. A folding ladder as claimed in any one of the preceding claims, in which the cap includes a handle for facilitating authorized removal thereof.
6. A folding ladder as claimed in any one of the preceding claims, which includes brackets for fixing the ladder to a host wall, the brackets having curved support surfaces engaged by the stiles, the curved support surfaces being formed with slots to receive fixing bolts.
7. A folding ladder as defined in which the lower edge of the cap is chamfered.
8. A folding ladder as defined which includes a security device for preventing unauthorized removal of the cap.
9. A folding ladder as claimed in Claim 8, in which the security device has a snap-fit engagement with the upper ends of the stiles.
10. A folding ladder as defined in which the cap includes a handle for facilitating authorized removal thereof.
II. A folding ladder as defined which includes brackets for fixing the ladder to a host wall, the brackets having curved support surfaces engaged by the stiles, the curved support surfaces being formed with slots to receive fixing bolts.
12. A folding ladder as claimed in any one of the preceding claims, which is formed as two or more sections which, in use, are disposed one above another and which includes an intermediate release device permitting opening of a lower ladder section independently of an upper ladder section.
13. A folding ladder substantially as hereinbefore described with reference to and as shown in the accompanying drawings.