GB2201988A

GB2201988A - Safety indicator for ladder

Info

Publication number: GB2201988A
Application number: GB08805083A
Authority: GB
Inventors: Berisford Gardner; Keith Turner
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-06-20
Filing date: 1988-03-03
Publication date: 1988-09-14
Also published as: GB8805083D0; DE3521689A1

Abstract

A safety device in the form of an angle indicator adapted for juxtaposition with a ladder stile an indicator, such as a bubble level, for displaying the relative positions of a locus relative to a datum position either to represent a safe working position for the ladder or to indicate an unsafe working position or positions to enable a safe position to be established in the light of the indication. The device is either placed against a ladder when setting the ladder in position or is incorporated in the ladder as an integral device. <IMAGE>

Description

SAFETY DEVICE This invention relates to a safety device. It is particularly concerned with a safety device for encouraging the safe usage of a ladder or like essentially longitudinal unit.

According to a first aspect of the present invention there is provided a safety device in the form of an angle indicator adapted for juxtaposition with a part of a longitudinal unit such as a ladder at least while the unit is at or near a safe working position, the device including a locus establishing means and an indicator for displaying the position of a locus established by the means at least while the indicator is juxtaposed with the unit, and an indicator for displaying the relative positions of the locus relative to a datum position either to represent a safe working position for the unit as such or to indicate an unsafe working position or positions so enabling a safe position to be established in the light of the indication.

Preferably the device is in the form of a housing incorporating a bubble level, the locus establishing means forming a part of the housing and adapted for juxtaposition as aforesaid, the indicator comprises a bubble level adapted to indicate when the locus establishing means and the datum position are related as aforesaid.

According to a second aspect of the present invention there is provided a ladder equipped with a safety device according to the first aspect.

An exemplary embodiment of the invention will now be described with reference to the accompanying drawings of which Figure 1 is a perspective view of a part of ladder equipped with a demountable safety device; and Figure 2 is a side view of Figure 1 when viewed in the direction of arrow A.

Figure 1 shows a part of a ladder 11 having side supports 12, 13 and rungs (typically rung 14). Support 12 has a front face 12A. In use the ladder 11 is disposed so that when viewed from the front it is vertical and when viewed from the side, as shown in Figure 2, at an angle A. It has been established as a good working practice that in use a ladder should be disposed in accordance with the one-in-four rule: that is to say for a horizontal extension of one unit the ladder should extend vertically a distance of four units. In this position the tangent of angle P is approximately 4.

To establish that the ladder 11 is disposed in accordance with the one-in-four rule safely device 15 is used. The device 15 comprises a housing 16 having a face 17 which forms a locus establishing means for juxtaposition with front face 12A of side support 12. Bubble level 17 is incorporated in the housing 16 and is aligned relative to the face 12A so that, with the face 17 clipped as shown against face 12A, the level 17 serves to indicate the amount by which the plane surface 16, and so the ladder 11, varies from a datum position corresponding to the appropriate one-in-four disposition. The device 15 is anchored to rung 14 by a chain.

The exemplary embodiment refers to a device making use of an indicator in the form of a bubble level it is also possible to make use of a device having an indicator in the form of a plumb line or pendulum. As before the locus establishing means comprises a surface or plurality of contacts having a similar function.

With a device according to the invention the safe working position of a ladder is readily and accurately established even by inexperienced users. This ready establishment of a safe operating position is achieved regardless of any local inclination of the surface upon which the ladder is disposed and regardless of any obstruction which may make an estimation of the ladder angle difficult to achieve.

The embodiment describes a demountable version of the safety device used in conjunction with a ladder. The invention also encompasses a ladder or other longitudinal device having an integral, built-in, version of a the safety device according to the invention. While the provision of an integral version of the device will increase the cost of producing the ladder the additional cost need not be great. In addition the use of an integral safety device avoids the need to obtain and mount such a device so providing a further simplification in the use of such a device.

Claims

1 A safety device in the form of an angle indicator adapted for juxtaposition with a part of a longitudinal unit such as a ladder at least while the unit is at or near a safe working position, the device including a locus establishing means and an indicator for displaying the relative positions of the locus relative to a datum position either to represent a safe working position for the unit as such or to indicate an unsafe working position or positions so enabling a safe position to be established in the light of the indication.

2 A safety device as claimed in Claim 1 in the form of a housing incorporating a bubble level, the locus establishing means forming a part of the housing and adapted for juxtaposition as aforesaid, the indicator comprises a bubble level adapted to indicate when the locus establishing means and the datum position are related as aforesaid.

3 A ladder equipped with a safety device according to any preceding claim.

4 A ladder as hereinbefore described with reference to the accompanying drawing.