GB2127472A - A ladder - Google Patents

Abstract

A ladder is disclosed which can be used as a step ladder, an extension ladder and a stair-well ladder. The ladder has a first ladder member (2) having a pair of stiles (6) and rungs extending therebetween, at least one bracket (14) pivotally mounted on the first ladder member (2), and a second ladder member (4) having a pair of stiles (6) and rungs extending therebetween. The stiles or one of the stiles of the second ladder member (4) are mounted for slidable movement longitudinally of the length thereof in the bracket (14) or a respective one of the brackets (14). The bracket has an arcuate slot (18) formed therein and is guided in its pivoting movement by a pin (20) fixed to the first ladder member (2). <IMAGE>

Description

SPECIFICATION A ladder This invention relates to a ladder, preferably a ladder which can be used in a plurality of configurations. Some such ladders are known, but all suffer from various disadvantages. For example, the ladder disclosed in U.S. Patent 1497253 employs a locking mechanism which requires the use of stiles of non-standard cross-section, thus increasing its cost of manufacture. Also a locking over-centre link is employed which it is easy for a user to omit to put into the locking position before use.

According to the present invention there is provided a ladder comprising a first ladder member having a pair of stiles and rungs extending therebetween, at least one bracket pivotally mounted on the first ladder member and having means for guiding the or each bracket between first and second positions at opposite ends of its pivoting movement, and a second ladder member having a pair of stiles and rungs extending therebetween, the stiles or one of the stiles of the second ladder member being mounted for slidable movement longitudinally of the length thereof in the bracket or a respective one of the brackets.

Preferably the bracket has an arcuate slot formed thereon and is guided in its pivoting movement by a pin fixed to the first ladder member.

An embodiment of the invention is shown in the accompanying drawings, in which: Fig. 1 is a side view of a ladder according to the invention, in use as a step ladder; Fig. 2 shows, on a larger scale than Fig. 1, a section taken on line X-X in Fig. 1; Fig. 3 shows, on a larger scale than Fig. 1, the upper end of one of the ladder members shown in Fig. 1; Fig. 4 shows a bracket forming part of the ladder of Fig. 1; Fig. 5 is a part section on line A-A in Fig. 4; and Fig. 6 shows a guide member forming part of the ladder of Fig. 1.

The illustrated ladder comprises a first ladder member 2 and a second ladder member 4, each having a pair of stiles 6 and a plurality of rungs 8 (not shown in Fig. 1, but one rung shown in Fig. 3).

Stops 10 of rubber or plastic material are provided at the lower end of ladder member 2 and at the upper and lower ends of ladder member 4. The ladder members themselves are preferably in the form of hollow rectangular sections of a metal, for example of an aluminium alloy. The sections may be formed by any appropriate method, for example by seam welding or extrusion. A hook-shaped bottom clip 1 2 is provided near the bottom of the ladder member 4 for a purpose described below.

The ladder members 2 and 4 are held together by a pair of brackets 14, one on each side of the ladder. One of the brackets 14 is shown in Fig. 1.

The bracket 14 is pivotally connected to the ladder member 2 for pivotal movement about an axis 16.

The bracket 1 4 has an arcuate slot 18, and a guide member 20, which is fixed to the ladder member 2, is slidable in the slot 1 8. The bracket 14 has a stile-engaging portion 22 in which a respective one of the stiles 6 of the ladder member 4 is free to slide longitudinally. One of the brackets is shown in more detail in Figs. 4 and 5. From these Figures it can be seen that the stile-engaging portion 22 comprises an upstanding wall 24 and an opposing wall portion 26 with a flange 28 extending at right-angles thereto which together define a space 30 in which a stile may be slidably received.As can also be seen in these Figures the slot 1 8 extends along a recess 1 9 defined by a wall 31, and one end of the recess takes the form of an enlarged portion 32 the purpose of which is described below.

The upper end of each stile 6 of the ladder member 2 carries a shaped stop 34. The stop 34 serves to engage a rung 8 of the ladder member 4 when the ladder is being used as a step ladder (as in Fig. 1). This is shown most clearly in Fig. 3 which shows a recess 36 engaging an edge of a rung 8. The stop 34 also provides a location on which to pivotally mount the bracket 14. This can be most clearly seen in Fig. 2 which shows that the stop 34 has a cylindrical aperture 38 which receives one end of a rivet 40. The other end of the rivet 40 is received in an aperture 42 in the bracket 14.

Fig. 6 shows in detail the guide member 20.

This comprises a cylindrical shank 44 and an enlarged head 46. Flats 48 are formed on opposite sides of the head 46 to form a flattened portion which can slide in the recess 1 9 without rotating.

The use of the ladder will now be described. In the position shown in Fig. 1 the ladder is a step ladder. In this position the guide members 20 are turned manually through 900 to cause the flatcarrying portions 48 to extend into the respective enlarged openings 32. This locks the ladder in position and prevents the ladder members 2 and 4 being shifted towards one another. Also, in this position the stops 34 engage a rung 8 of the ladder member 4 to prevent the brackets 14 sliding downwardly on the ladder member 4.

The ladder can also be used as a stair-well ladder or in the situation where the surface on which one of the ladder members stands is at a different height to that on which the other of the ladder members stands. To bring the ladder from the position of Fig. 1 into a position in which it can be used as a stair-well ladder, the ladder is first unlocked by turning the guide members 20 through 900. The ladder member 4 is then pivoted towards the ladder member 2 about the axis 1 6 to a sufficient extent for the recess 36 of the stops 34 to disengage the rung 8. The ladder member 4 is then slid upwardly, its stiles sliding through the stile-engaging portions 22 of the brackets 14, until it is at the desired height.The ladder member 4 is then pivoted away from the ladder member 2 until the stops 34 engage a rung 8 of the-la,dder member 4 situated lower than the previouly engaged rung, and the ladder is then re-locked by turning the guide members through 900.

Yet another use of the ladder is as an extension ladder. To bring the ladder from the position of Fig.

1 into a postion in which it can be used as an extension ladder, the ladder is first unlocked by turning the guide members through 900. The ladder member 4 is then pivoted towards the ladder member 2 until the members 2 and 4 lie nearly parallel to one another. The ladder member 4 is then slid upwardly, its stiles sliding through the stile-engaging portions 22 of the brackets 14, until it is just above the desired height, and the ladder member 4 is then lowered to cause the bottom clip 12 to hook over a rung 8 of the ladder member 2. The upper end of the ladder member 4 is then in a position such as that indicated in phantom in Fig. 1.

Claims (6)

1. A ladder comprising a first ladder member having a pair of stiles and rungs extending therebetween, at least one bracket pivotally mounted on the first ladder member and having means for guiding the or each bracket between first and second positions at opposite ends of its pivoting movement, and a second ladder member having a pair of stiles and rungs extending therebetween, the stiles or one of the stiles of the second ladder member being mounted for slidable movement longitudinally of the length thereof in the bracket or a respective one of the brackets.

2. A ladder according to claim 1, wherein the bracket has an arcuate slot formed therein and is guided in its pivoting movement by a pin fixed to the first ladder member.

3. A ladder according to claim 2, wherein locking means are provided for enabling the pin to be locked with respect to the bracket at a locking position which the pin occupies when the first and second ladder members are pivoted apart from one another.

4. A ladder according to claim 3, wherein at least a portion of the pin is of non-circular crosssection and is rotatable at the said locking position into an orientation in which it is prevented from sliding along the arcuate slot.

5. A ladder according to any preceding claim, wherein the stiles and rungs are of an aluminium alloy.

6. A ladder substantially as herein described with reference to the accompanying drawings.