GB2358214A

GB2358214A - Ladder top cap

Info

Publication number: GB2358214A
Application number: GB0000759A
Authority: GB
Inventors: James Dimitrios Williamson; Adrian Butter; David Simon Draddy James
Original assignee: SGB Services PLC
Current assignee: SGB Services PLC
Priority date: 2000-01-13
Filing date: 2000-01-13
Publication date: 2001-07-18
Also published as: GB0000759D0

Abstract

A top cap (12) for a ladder has a body defining a portion (18) to be received within the end of a hollow ladder stile (2) and an end face (13) to be exposed when the cap is mounted on the ladder stile. The portion to be received within the stile defines a transverse bore (21). The bore defines a resilient snap fastening means adapted to cooperate with corresponding means (28) on a mounting pin (25) which passes through the bore and co-aligned apertures (9,10) in the stile (2).

Description

2358214 PATENT ACT 1977 P13973QB-NF/jsd

DESCRIPTION OF INVENTION

4MPROVEMENTS IN OR RELATING TO A LADDER FITTING" THE PRESENT INVENTION relates to a ladder fitting, and more particularly relates to a fitting suitable for use with a ladder formed with hollow stiles. It is envisaged that the fitting of the invention may be of particular use in connection with an extension ladder.

According to one aspect of this invention there is provided a top cap for a ladder stile, the top cap having a body defining a portion to be received within the end of a hollow ladder stile and an end face to be exposed when the cap is mounted on the ladder stile, the portion to be received within the stile defining a transverse bore, the bore defining resilient snap fastening means adapted to co-operate with corresponding means on a mounting pin passing through the bore and co-aligned apertures in the stile.

The top cap may be moulded from a plastics material.

Preferably the snap fastening means are in the form of one or more tabs located centrally of the bore so that the top cap is symmetrical.

2 Conveniently the top cap defles at least a partial skirt about It he periphery of the end face adapted to embrace the end party of a hollow st 1e, when the cap is mounted on the stile.

Preferably an inclined face is defirted by the cap, at least one end of t4e end face and the face may be inclined at an angle of 20 degrees to the axis pf a stile when the cap is mounted on a stile.

This invention also provides a ladder having two hollow stiles alq h d,' a plurality of rungs and incorporating a top cap according to any one of tie

Claims

preceding Claims mounted on a stile of the ladder, with a mounting pin pas 1 g through co-aligned apertures in opposed side-walls of the hollow stile andi we said bore, the mounting pin defining a groove to receive said resilient fasten' 1 ig means with a snap action. Conveniently the mounting pin projects beyond one of the side-w,a.Is and a bung is mounted on the projecting end of the pin. The bung may,)e mounted on the pin with a snap action. The pin may define an abu nt between a conical terminal head and a tapering intermediate portion andItie bung has a bore to receive the pin, the bore being associated with inwaf ly directed lugs to engage the abutment to provide the snap action. Preferably the bung presents two orthogonal faces, one face abuttin a top clip, and the other face extending parallel with, but spaced from a guide element forming part of the top clip, the bung and the top clip forming a g#ide for a stile of an adjacent ladder section. The top clip maybe secured to the tlle with self piercing screws which pass through apertures formed in part of thel tb p clip that extends perpendicularly to the guide element. 3 In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is an exploded perspective view of an end part of one stile of a ladder showing various components, including a top cap and a top clip, that are mounted on the end of the stile of the ladder, FIGURE 2 is a part sectional view illustrating the top cap of Figure 1 inserted in the stile of the ladder, the top cap being shown in section, FIGURE 3 is a view showing an intermediate stage in the assembly of the ladder, FIGURE 4 is a view corresponding to Figure 3 showing a further stage in the assembly of the ladder, FIGURE 5 is a sectional view of the ladder taken on line V-V of Figure 4, FIGURE 6 is a view corresponding to Figure 4 showing yet a further stage in the assembly of the ladder, FIGURE 7 is a view corresponding to Figure 6 showing a subsequent further stage in the assembly of the ladder, FIGURE 8 is a perspective view of part of an extension ladder showing two stiles provided with fittings of the type illustrated in Figures 1 to 7. 4 Referring initially to Figure 1 of the accompanying drawings, a sect,d 1 1 n of an extending ladder is of conventional form, being provided with two parallel stiles, only one of which, 2, is illustrated. The ladder incorporatos a plurality of rungs only one of which, 3, is illustrated. One end of 4 of the stile, as shown in Figure 1, is intended to be die upper end of the stile. The stile is either formed as a hollow extrusio, of aluminium or an aluminium alloy, or formed as a seam welded rolid r aluminium or aluminium alloy hollow section. The stile has two relatiel,, large opposed parallel side walls 5, 6, inter-connected by two relatively nartc W side walls 7, 8. A pair of aligned apertures 9, 10 are provided in the relatively 14r ge walls 5 and 6. A moulded plastics material top cap 12 is provided which is adapte to be mounted on the open end 4 of the stile. The end cap 12 presents an i! d face 13 of generally rectangular form adapted to be substantially nonnal to'!tie axis of the stile of the ladder. The end face 13 is provided, at each end of, e rectangular end face, with a partial skirt 14, 15. The partial skirt 14, l$ Js adapted to embrace the end part of the stile 2. As will be described be ow when the end cap is mounted on the stile, part of the end cap is inserted intolithe open end of the stile. The skirt 14, 15 will be on the exterior of the stile thus the end cap will protect the end of the stile, which is susceptiblil to j damage. The junction between the exterior of the partial skirt 14, 15 at e 1 ph end of the end cap, and the rectangular end face 13 defines an inclined rib d wall 16, 17. The ribbed wall is so located that the plane of the wall make an angle of approximately 20' with the axis of the stile. The reason for this is at a ladder, when correctly positioned against a wall, makes an angle of 70' to the ground and 20' to the wall, and thus an end face, such as the end face 16, 17, will fninly abut the wall when the ladder is in the correct position. On the rear part of the end face 13 is a projection 18 which is generally of rectangular section and which is dimensioned to be received within the open end of the stile 2. The nature of the projection can be seen more clearly in Figure 2. The projection 18 has two opposed chamfered faces 19, 20, on the relatively narrow side faces thereof remote from the end face 13 to facilitate insertion of the projection 18 into the hollow end of the stile. The projection 18 is provided with a transverse bore 21. In the centre of the bore, as can be seen in Figure 2, four evenly spaced diametrically inwardly extending tabs 22 are provided. The four tabs thus extend radially into the bore at a substantially central position. The tabs are resilient to provide a snap fimction, as will become clear from the following description. The end cap is symmetric and can be used either way round. Two bores 23, 24 are provided in the end cap 12, opening on the end face 13, to minimise the quantity of material used in fabricating the end cap. A fixing pin 25, for example, of steel, is provided having a head 26 and a shank 27. The shank 27 is provided with a circumferential groove 28 adapted to receive the tabs 22, with a snap function.. The fixing pin is also provided with a further portion 29 which is tapered and which abuts against the larger diameter end of a terminal conical head 30, defining an abutment which also provides a further snap function. 6 The pin 25 is of such a length that it will pass through the co-aliori,ed apertures 9 and 10 of the stile 2, whilst simultaneously passing through! the bore 21 of the top cap when the projection 18 is received within the open le d of the stile 2, with part of the pin 25 projecting on the far side of the stile. tliat part of the pin includes the tapered portion 29 and the conical head 30. Tifis part of the pin is adapted to engage a bung 31 which is of generally sqOare cross-section with rounded corners, and which has an axially extendirig bore 32. The bore 32, as can be seen most clearly in Figure 5, is provided ll.th diametrically opposed inwardly directed lugs 33 adapted to form a snap-fit th V. the rear face of the conical head 30 of the fixing pin. As can be seen, there re, that initially the top cap 12 will have the projection 18 thereof inserted intoi the open end 4 of the stile 2, and subsequently the pin 25 will be passed thrugh 1 the apertures 9 and 10 co-aligned with the bore 21 until the tabs 22 engagel tk peripheral groove 28 formed in the pin 25. Subsequently the bung 31 wil he urged onto the then exposed end part of the pin 25 until the lugs 33 within' the bore 32 engage, with a snap action, the abutment between the conical hea 30 and the tapering portion 29 of the pin 25. A top clip 41 is provided. The top clip 41 is part of a generally tf,l, 55sectioned extrusion formed of aluminium or the like. The top clip 41 prescot' a i: relatively large rectangular plate 42, formed on one arm of the 'L' and a ide 0 1 portion 43, formed by the other arm of the U, extending perpendicularly fc'm one end of the rectangular plate 42. The rectangular plate 42 is provided with two apertures 43, 44 adao d to receive self-tapping screws 45, 46 that may be used to secure the top cli 41 to the stile 2. It is intended that the top clip 41 will be located with the pla 42 in contact with the stile, with one edge of the plate in abutment with one facl lof the bung 3 1. The top clip will be positioned so that there is an approp,,te 7 distance between the under-surface of the guide element 43 and the face of the bung 31 which is closest to the guide element 43. The face of the bung that is closest to the guide element 43 is orthogonal to the face that abuts the bung. The self-piercing screws will then be used to secure the top clip in position on the ladder. The top clip is thus selectively positioned ( see Figure 6) so that the spacing between the guide element 43 and the bung 3 1 is just sufficient to receive the stile of the next adjacent ladder section of an extending ladder. The self piercing screws 45, 46 are then used to secure the top clip in place ( see Figure 7). A single size top clip may be positioned, relative to the bung, to receive one of a plurality of different sizes of stile of an adjacent ladder. Thus, instead of having to provide a different top clip extrusion for each size of stile, a few different extrusions may be able to accommodate a complete range of stile sizes. This may reduce the costs of manufacturing a range of ladders. The position of the top clip is selected to control the "overlap" of the adjacent ladder sections, and also serves to restrict the maximum "opening" angle between adjacent ladder sections to I O'C. At this stage it is to be mentioned that in a conventional extending ladder the size of the stile of each ladder section is slightly less than the size of the stile of the adjacent ladder section. Thus, when manufacturing a range of ladders, it is desirable to be able to provide various top guide assemblies which can accommodate any one of a number of different stile sizes. Previously it has been proposed to provide a separate extruded clip for each size of stile. This is, of course, a relatively expensive expedient. However, it is to be appreciated that in using an arrangement as described, the top clip can be positioned appropriately, relative to the top bung 3 1, to constitute a guide to receive a stile 8 S of any selected size within a predetermined range of sizes, the range of size' 11 dependent upon the size of the plate 42 of the top clip 41, and also itie dimension of the side walls 6 of the stile 2. Nevertheless, by utilising11 M 1 1 arrangement as disclosed in the present invention, it is envisaged that it wilf, k pe possible to manufacture a commercially sensible range of ladders whi ist utilising a minimum number of different components. Figure 8 illustrates part of an extension ladder utilising a ladder -ence to Figures 1 to 7. It can be seen that lhe section 1 as described with refei ladder section 1 is operating in conjunction with a second ladder sectioni 50 which has two stiles 51, 52, and a plurality of rungs 53, 54. It can be seen 1h 1 at i 1 the stiles 51, 52 are snugly received between the bungs 31 and the top clip51 41 so that the ladder section 50 may slide relatively freely relative to the ladr section 1, but movement in a plane transverse to the plane of the ladd,b,r section 1 is prevented. In the present specification "comprise" means "includes or consists 1.or, ' and "comprising" means "including or consisting of". The features disclosed in the foregoing description, or the follo 'il g claims, or the accompanying drawings, expressed in their specific forms o In terms of a means for performing the disclosed function, or a method or proess for attaining the disclosed result, as appropriate, may, separately, or in combination of such features, be utilised for realising the invention in divdrse forms thereof. 9 CLAIMS:

1. A top cap for a ladder stile, the top cap having a body defining a portion to be received within the end of a hollow ladder stile and an end face to be exposed when the cap is mounted on the ladder stile, the portion to be received within the stile defining a transverse bore, the bore defining resilient snap fastening means adapted to co-operate with corresponding means on a mounting pin passing through the bore and coaligned apertures in the stile.

2. A top cap according to Claim 1 moulded from a plastics material.

3. A top cap according to Claim 1 or 2 wherein the snap fastening means are in the form of one or more tabs located centrally of the bore so that the top cap is symmetrical.

4. A top cap according to any one of the preceding Claims wherein the top cap defmes at least a partial skirt about the periphery of the end face adapted to embrace the end party of a hollow stile when the cap is mounted on the stile.

5. A top cap according to any one of the preceding Claims wherein an inclined face is defined by the cap at least one end of the end face.

6. A top cap according to Claim 5 wherein the inclined face is inclined at an angle of 20 degrees to the axis of a stile when the cap is mounted on a stile.

7. A ladder having two hollow stiles and a plurality of rungs and incorporating a top cap according to any one of the preceding Claims mounted on a stile of the ladder, with a mounting pin passing through co-ali4r'ed apertures in opposed side-walls of the hollow stile and the said bore,l ie mounting pin defining a groove to receive said resilient fastening means with a snap action.

8. A ladder according to Claim 7 wherein the mounting pin projp pts i 1 beyond one of the side-walls and a bung is mounted on the projecting en'; of the pin.

9. A ladder according to Claim 8 wherein the bung is mounted on the': pin with a snap action.

10. A ladder according to Claim 9 wherein the pin defines an abu 'nt between a conical terminal head and a tapering intermediate portion and! the bung has a bore to receive the pin, the bore being associated with inwardly directed lugs to engage the abutment to provide the snap action.

11. A ladder according to Claims 8, 9 or 10 wherein the bung presents 0 orthogonal faces, one face abutting a top clip, and the other face extening parallel with, but spaced from a guide element forming part of the top clip,' the bung and the top clip forming a guide for a stile of an adjacent ladder sectioti.:

12. A ladder according to Claim 11 wherein the top clip is secured toi the stile with self piercing screws which pass through apertures formed in pan of the top clip that extends perpendicularly to the guide element.

13. A top cap substantially as herein described with reference to and as shown in the accompanying drawings.

11

14. A ladder substantially as herein described with reference to and as shown in the accompanying drawings.