GB2145146A

GB2145146A - Ladder attachments

Info

Publication number: GB2145146A
Application number: GB08421063A
Authority: GB
Inventors: Samuel David Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-08-19
Filing date: 1984-08-18
Publication date: 1985-03-20
Also published as: GB2145146B; GB8322442D0; GB8421063D0

Abstract

The ladder attachment is for location in a hollow open ended non-circular rung of a metal ladder. The attachment comprises an elongate cross bar 10 mounting a wall engageable wheel 11 at each end, one of which is removable to enable one end of the cross bar to pass through the rung. Pins 15-18 are mounted on the cross bar such that two 16-17 locate inside the rung and two 15, 18 are external of the rung. One external pin 18 is fixed to halt movement of the cross bar through the rung. The two inner pins 16, 17 are retractable to locate within the rung and engage the wall thereof to prevent rotation of the cross bar. The other outer pin 15 is retractable so that it can pass through the rung then expand once it exits from the rung. Alternatively (Fig 7), the other outer pin 30 is removable to be positioned on the cross bar once it has been located through the rung, and a spring 31 is placed between the pin 30 and the ladder stile 13' to prevent lateral movement of the cross bar. The cross bar may be in three parts (Fig. 6), a central part 20 to locate through in the rung and extension 21 telescopic on the centre part 20. <IMAGE>

Description

SPECIFICATION Ladder attachments This invention relates to ladder attachments.

It is now well known to attach to the upper end of a ladder, an elongate cross bar having wheels at its ends for the purpose of more safely supporting the ladder against a wall. Normally, the cross bar is attached by hooks which grip a pair of rungs of the ladder or by brackets which engage the ladder stiles.

An object of the present invention is to provide an alternative means for connecting the cross bar to a ladder, particularly a metal ladder having hollow open ended rungs.

According to the present invention there is provided a ladder attachment for location in a hollow open ended non-circular rung of a metal ladder, said attachment comprising an elongate cross bar mounting a wall engageable wheel at each end, at least a portion of the cross bar being of external dimensions such that it can locate within the hollow rung and be non-rotatable therein or have means associated therewith to prevent rotation, and stop means provided to limit movement of the cross bar through the rung so that a predetermined length of cross bar extends from each side of the ladder.

Preferably, the cross bar is a unitary cylindrical member at least one wheel being moveable so that the cross bar can pass through the hollow rung.

Preferably also, the means to prevent rotation and the stop means are pins which extend through the cross bar at locations therealong in the same plane, the pins to extend beyond the dimensions of the cross bar, two pins being so positioned that they locate externally of the ladder stiles and thus prevent lateral movement of the cross bar in the rung at least one of these pins being retractable or removable to enable one end of the cross bar to pass through the rung, and at least two pins located within the rung to extend across the major cross sectional dimension thereof and prevent rotation of the cross bar.

Preferably a spring surrounds the cross bar between one of the external stop pins and the adjacent ladder stile.

Alternatively, the cross bar may comprise a centre tube for location in the hollow rung and to extend beyond each side and telescopically mounted extension arms mountable on the extended portions of the centre tube and carrying the wheels.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a front view of the upper portion of a ladder carrying an attachment according to the invention; Figs. 2 to 5 are sectional views of Fig. 1; and Figs. 6 and 7 are elevations of alternative arrangements.

Referring firstly to Figs. 1 to 5, a unitary elongate cylindrical cross bar 10 is provided having a wheel 11 at each end, at least one (in this embodiment both) being removably retained by a lynch pin 12.

One wheel can therefore be removed and the cross bar pushed through the hollow open-ended rung 13 of a metal ladder 13', the cross bar being dimensioned to permit this. The rung is non-circular in cross section; it may be square or D-shaped.

Six pins 14--19 are mounted on the cross bar, all in one plane and project out of the cross bar to different lengths. The pins are spaced along the cross bar and positioned for different purposes. The two outer pins 14, 19 limit the distance the wheels can slide along the cross bar, i.e. the pins 14, 19 are located close to each end of the cross bar and are of a length which permits the relevant one to pass through the rung when the cross bar is being mounted. The centre two pins 16, 17 are identical to the outer pins 14, 19; they can locate within the rung when the cross bar is in position and for a square extend diametrically across the inside of the rung, thus preventing rotation of the cross bar.

The intermediate pins 15, 18 are longer than the others and at least one is spring loaded so that it can be depressed to enable it to pass through the rung.

When it exits it expands to lie alongside a stile and prevent return movement of the crossbar; at the same time the other pin abuts the other stile.

If desired, a sleeve or a collar (not shown) may be located round portion of the cross bar to be contained within the rung, the sleeve or collar being shaped externally to provide an additional or alternative means for preventing rotation of the cross bar.

In an alternative, Fig. 6, the cross bar is in three parts; a centre tube 20 which locates in the rung 13 as described above and extends beyond each side of the ladder, and two extension arms 21 which telescopically engage the projecting portions of the centre tube. The extension arms 21 may be straight, but are preferably L-shaped, i.e. at the outer end of each arm 21 is a sleeve 22 at right angles thereto, and the sleeve 22 carries a shaft 23 which has a wheel 11 at its end and carry a wheel-mounting shaft at their ends.

In such an arrangement, the sleeve or collar is provided to countertorqueforces caused by the wheels being spaced from the plane of the cross bar by the L-arms.

In a further embodiment, illustrated in Fig. 7 the retractable stop pin 15 is replaced by a removable pin 30 which can locate in holes provided in the cross bar at a small distance away from the adjacent ladder stile 13'. A spring 31 is placed between the stile and the stop pin 30 and prevents lateral movement of the cross bar on the ladder. In this embodiment, one end of the cross bar is passed through the ladder rung 13 until prevented from further movement by the fixed stop pin 18. The spring 31 is then slid along the said end of the cross bar to abut the stile and a washer 33 is slid along the cross bar to abut the spring. The stop pin 30 is then located in position to secure the spring 31 between it and the stile under pressure.

1. A ladder attachment for location in a hollow open ended non-circular rung of a metal ladder, said attachment comprising an elongate cross bar

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Ladder attachments This invention relates to ladder attachments. It is now well known to attach to the upper end of a ladder, an elongate cross bar having wheels at its ends for the purpose of more safely supporting the ladder against a wall. Normally, the cross bar is attached by hooks which grip a pair of rungs of the ladder or by brackets which engage the ladder stiles. An object of the present invention is to provide an alternative means for connecting the cross bar to a ladder, particularly a metal ladder having hollow open ended rungs. According to the present invention there is provided a ladder attachment for location in a hollow open ended non-circular rung of a metal ladder, said attachment comprising an elongate cross bar mounting a wall engageable wheel at each end, at least a portion of the cross bar being of external dimensions such that it can locate within the hollow rung and be non-rotatable therein or have means associated therewith to prevent rotation, and stop means provided to limit movement of the cross bar through the rung so that a predetermined length of cross bar extends from each side of the ladder. Preferably, the cross bar is a unitary cylindrical member at least one wheel being moveable so that the cross bar can pass through the hollow rung. Preferably also, the means to prevent rotation and the stop means are pins which extend through the cross bar at locations therealong in the same plane, the pins to extend beyond the dimensions of the cross bar, two pins being so positioned that they locate externally of the ladder stiles and thus prevent lateral movement of the cross bar in the rung at least one of these pins being retractable or removable to enable one end of the cross bar to pass through the rung, and at least two pins located within the rung to extend across the major cross sectional dimension thereof and prevent rotation of the cross bar. Preferably a spring surrounds the cross bar between one of the external stop pins and the adjacent ladder stile. Alternatively, the cross bar may comprise a centre tube for location in the hollow rung and to extend beyond each side and telescopically mounted extension arms mountable on the extended portions of the centre tube and carrying the wheels. Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a front view of the upper portion of a ladder carrying an attachment according to the invention; Figs. 2 to 5 are sectional views of Fig. 1; and Figs. 6 and 7 are elevations of alternative arrangements. Referring firstly to Figs. 1 to 5, a unitary elongate cylindrical cross bar 10 is provided having a wheel 11 at each end, at least one (in this embodiment both) being removably retained by a lynch pin 12. One wheel can therefore be removed and the cross bar pushed through the hollow open-ended rung 13 of a metal ladder 13', the cross bar being dimensioned to permit this. The rung is non-circular in cross section; it may be square or D-shaped. Six pins 14--19 are mounted on the cross bar, all in one plane and project out of the cross bar to different lengths. The pins are spaced along the cross bar and positioned for different purposes. The two outer pins 14, 19 limit the distance the wheels can slide along the cross bar, i.e. the pins 14, 19 are located close to each end of the cross bar and are of a length which permits the relevant one to pass through the rung when the cross bar is being mounted. The centre two pins 16, 17 are identical to the outer pins 14, 19; they can locate within the rung when the cross bar is in position and for a square extend diametrically across the inside of the rung, thus preventing rotation of the cross bar. The intermediate pins 15, 18 are longer than the others and at least one is spring loaded so that it can be depressed to enable it to pass through the rung. When it exits it expands to lie alongside a stile and prevent return movement of the crossbar; at the same time the other pin abuts the other stile. If desired, a sleeve or a collar (not shown) may be located round portion of the cross bar to be contained within the rung, the sleeve or collar being shaped externally to provide an additional or alternative means for preventing rotation of the cross bar. In an alternative, Fig. 6, the cross bar is in three parts; a centre tube 20 which locates in the rung 13 as described above and extends beyond each side of the ladder, and two extension arms 21 which telescopically engage the projecting portions of the centre tube. The extension arms 21 may be straight, but are preferably L-shaped, i.e. at the outer end of each arm 21 is a sleeve 22 at right angles thereto, and the sleeve 22 carries a shaft 23 which has a wheel 11 at its end and carry a wheel-mounting shaft at their ends. In such an arrangement, the sleeve or collar is provided to countertorqueforces caused by the wheels being spaced from the plane of the cross bar by the L-arms. In a further embodiment, illustrated in Fig. 7 the retractable stop pin 15 is replaced by a removable pin 30 which can locate in holes provided in the cross bar at a small distance away from the adjacent ladder stile 13'. A spring 31 is placed between the stile and the stop pin 30 and prevents lateral movement of the cross bar on the ladder. In this embodiment, one end of the cross bar is passed through the ladder rung 13 until prevented from further movement by the fixed stop pin 18. The spring 31 is then slid along the said end of the cross bar to abut the stile and a washer 33 is slid along the cross bar to abut the spring. The stop pin 30 is then located in position to secure the spring 31 between it and the stile under pressure. CLAIMS

1. A ladder attachment for location in a hollow open ended non-circular rung of a metal ladder, said attachment comprising an elongate cross bar mounting a wail engageable wheel at each end, at least a portion of the cross bar being of external dimensions such that it can locate within the hollow rung and be non-rotatable therein or have means associated therewith to prevent rotation, and stop means provided to limit movement of the cross bar through the rung so that a predetermined length of cross bar extends from each side of the ladder.

2. A ladder attachment as claimed in claim 1, in which the cross bar is a unitary cylindrical member at least one wheel being movable so that one end of the cross bar can pass through the hollow rung.

3. A ladder attachment as claimed in claim 1 or 2 in which the means to prevent rotation and the stop means are pins which extend through the cross bar at locations therealong in the same plane, the pins to extend beyond the dimensions of the cross bar, two pins being so positioned that they locate externally of the ladder stiles and thus prevent lateral movement of the cross bar in the rung at least one of these pins being retractable or removable to enable one end of the cross bar to pass through the rung and at least two pins located within the rung to extend across the major cross sectional dimension thereof and prevent rotation of the cross bar.

4. A ladder attachment as claimed in claim 3 in which a spring surrounds the cross bar between one of the external stop pins and the adjacent ladder stile.

5. A ladder attachment as claimed in claim 1 or 2, in which the cross bar comprises a centre tube for location in the hollow rung and to extend beyond each side and telescopically mounted extension arms mountable on the extended portions of the centre tube and carrying the wheels.

6. A ladder attachment, substantially as hereinbefore described with reference to Figs. 1 to 5 or Figs. 1 to 5 when modified by Fig. 6 or Fig.

7.