GB2556939A

GB2556939A - Locking Arrangement

Info

Publication number: GB2556939A
Application number: GB1620074.3A
Authority: GB
Inventors: John Richardson Mark; Robert King Brian
Original assignee: Power Towers Ltd
Current assignee: Power Towers Ltd
Priority date: 2016-11-28
Filing date: 2016-11-28
Publication date: 2018-06-13
Anticipated expiration: 2036-11-28
Also published as: GB201620074D0; WO2018096352A1; GB2556939B

Abstract

A locking arrangement for apparatus having a first component and a second component moveable relative to each other in a vertical direction such as an access platform having an elevating work platform. The locking arrangement comprises a first locking member (40), which is a pendulum or bob suspended with respect to the first component (12), such as an access platform, so as to be pivotable under gravity and a second locking member (20), which is a stop plate, fixed with respect to a second component (10), such as a chassis. The device incorporates a stop portion that cooperates with pendulum (40) to permit relative movement of the first and second components (12, 10) in a vertical direction only when the stop portion (24, 26) of the second locking member (20) adopts a horizontal orientation or deviates therefrom by less than a predetermined amount. This can be achieved by having the distal end of the pendulum terminate in an enlarged head (4,7) which incorporates hooks (48, 50) which will interact with the stop plate or second locking member (20) when the second locking member (20) has deviated sufficiently from the horizontal.

Description

(54) Title of the Invention: Locking Arrangement

Abstract Title: Pendulum locking arrangement for an elevating work platform (57) A locking arrangement for apparatus having a first component and a second component moveable relative to each other in a vertical direction such as an access platform having an elevating work platform. The locking arrangement comprises a first locking member (40), which is a pendulum or bob suspended with respect to the first component (12), such as an access platform, so as to be pivotable under gravity and a second locking member (20), which is a stop plate, fixed with respect to a second component (10), such as a chassis. The device incorporates a stop portion that cooperates with pendulum (40) to permit relative movement of the first and second components (12, 10) in a vertical direction only when the stop portion (24, 26) of the second locking member (20) adopts a horizontal orientation or deviates therefrom by less than a predetermined amount. This can be achieved by having the distal end of the pendulum terminate in an enlarged head (4,7) which incorporates hooks (48, 50) which will interact with the stop plate or second locking member (20) when the second locking member (20) has deviated sufficiently from the horizontal.

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At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Title: Locking Arrangement

Field of the Invention

This invention relates to a locking arrangement, and concerns a locking arrangement for apparatus having components relatively moveable in a vertical direction in use of the apparatus, such as an access platform, access tower, crane etc. in which a component is elevated with respect to a supporting chassis.

Background to the Invention

Many types of such apparatus (e.g. access platforms) are required to have an arrangement to determine the angle of deviation from horizontal of the chassis, and to provide an interlock to prevent the platform or other component from being elevated is into a potentially dangerous condition. A warning alarm, e.g. audible and/or visual, may also be generated. Known arrangements typically operate electronically and use reed switches or other electronic angle or tilt sensors.

The present invention seeks to provide an alternative approach.

Summary of the Invention

The present invention provides a locking arrangement for apparatus having a first component and a second component moveable relative to each other in a vertical direction in use of the apparatus, the locking arrangement comprising a first locking member fixed with respect to the first component and suspended so as to be pivotable under gravity, and a second locking member fixed with respect to the second component and having a stop portion that cooperates with the first locking member to permit relative movement of the first and second components in a vertical direction only when the stop portion of the second locking member adopts a horizontal orientation or deviates therefrom by less than a predetermined amount.

Because the first component is suspended so as to be pivotably under gravity, it will generally adapt a vertical orientation regardless of the orientation of the apparatus.

If the apparatus, and hence the stop portion, is in a generally horizontal orientation (deviating by less than the predetermined amount), movement of the first locking member past the stop portion of the second locking member will not be impeded on relative movement of the first and second components away from each other, and the apparatus can be moved from a lowered condition to a fully raised condition, e.g. raising an elevating platform.

However, if the deviation from horizontal of the apparatus, and hence the stop portion, equals or exceeds the predetermined amount, e.g. as a consequence of it being on an inclined surface, the first locking member engages the stop portion and so limits relative movement of the first and second components, preventing the apparatus from is adopting a fully raised condition.

The arrangement thus effectively constitutes a tilt sensor that provides a simple mechanical interlock preventing raising of the apparatus when the tilt equals or exceeds the predetermined amount, without the need for powered tilt sensors.

The second component is typically stationary, in use of the apparatus, e.g. being a chassis, with the second component being moveable, e.g. being an elevating platform with respect of which the second locking member is suspended.

The reverse arrangement is also possible, with the first component (with the suspended first locking member) being stationary and the second component moving with respect thereto.

The first locking member is typically of elongate form, having an elongate axis, e.g.

comprising an elongate rod suspended with the elongate axis extending vertically.

The first locking member desirably includes an enlarged diameter portion, typically at or near the lower end. The enlarged portion may for instance comprise one or more outwardly-extending flanges, projections, juts, protrusions, etc., for example a pair of opposed projections etc. or a circumferential projection etc. extending around the full periphery of the member. The enlarged portion is sized so as not to engage the stop portion of the second member when the apparatus is oriented horizontally, e.g. being located on a horizontal surface, and also when oriented with a slight inclination up to the predetermined amount (e.g. 5 °, 10 °, 15°), permitting relative upwards movement of the first locking member past the second locking member, but preventing such movement when the predetermined amount is reached or exceeded as a result of the enlarged portion engaging the stop portion.

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Suspension of the first locking member is conveniently by means of a pivot arrangement. For instance a first pivot arrangement may permit movement in a vertical plane about a horizontal axis. Two orthogonal pivot arrangements may be employed to enable multidirectional movement. Alternatively, other pivot is arrangements may be used to provide a multi-axis pivot, e.g. a gimble bearing.

The stop portion of the second locking member is conveniently defined by one or more edge portions of the second locking member, e.g. edge portions of an opening in the second locking member. The opening may, for example, comprise a slit, an aperture or a cutout etc. The edges of the opening may be straight or curved. In a simple case, the opening comprises a circular aperture or a straight-edged slit. The profile of the opening in a vertical direction effectively reduces as the apparatus is tilted.

One preferred arrangement uses an opening comprising a slit or aperture having a pair of opposed edges, with a cutout in each of the opposed edges. This may produce a cruciform opening. Such an opening can conveniently be used with a first locking member with an enlarged portion comprising a pair of opposed projections.

The predetermined amount of permitted deviation from horizontal may be selected as appropriate having regard to the apparatus, e.g. taking into account the extent of elevation involved, loads carried etc., and may be set appropriately e.g. at 5°, 10°, 15°, 20°.

The predetermined amount is determined by the relative geometry of the first and second locking members, and can be regulated as desired by adjusting the geometry.

The first locking member and at least the stop portion of the second locking member should be of rigid material, and are typically made of metal, e.g. steel.

The locking arrangement finds application in connection with access platforms having an elevating work platform, access towers, cranes etc., having an elevating component such as a work platform, boom etc. that is elevated in use with respect to a chassis.

The arrangement finds particular application on mobile equipment, such as mobile access platforms etc., that are used in a variety of locations, possibly including those with non-horizontal surfaces where it would be potentially dangerous to elevate the is component. The mobile apparatus typically has ground-engaging wheels mounted on a chassis, to facilitate movement of the apparatus, and may be self-propelled or otherwise.

In a further aspect, the invention provides an access tower comprising a locking 20 arrangement in accordance with the invention.

An embodiment of the invention will be described, by way of illustration, with reference to the accompanying drawings, in which:

Figure 1 is an end view, partly in section, of part of a locking arrangement for an elevating access platform;

Figure 2 is a side view of the arrangement of Figure 1;

Figure 3 is a plan view of the arrangement of Figure 1;

Figures 4 to 6 correspond to Figures 1 to 3, and illustrate movement of the pendulum.

Detailed Description of the Drawings

The drawings illustrate a locking arrangement forming part of an elevating access platform apparatus comprising a chassis represented at 10 (constituting the second component) mounted thereon for elevating movement in a vertical direction to raise the platform above the ground. The elevating access platform can be of generally conventional construction, as is well known in the art.

A rigid stop plate 20 (constituting the second locking member) is fixed with respect to io chassis 10 and has a rectangular central cutout portion 22, seen best in Figure 3, defining stop portions. Each edge of the cutout portion is of C-shaped configuration, having a central portion 24,26 with protruding flanges 28,30 and 32,34. The plate defines a pair of opposed elongate stop portions 24,26 along a first plane Pl, and two pairs of opposed stop portions constituted by flanges 28,30 and 32,34 facing each is other along a perpendicular second plane P2.

An elongate, rigid pendulum 40 (constituting the first locking member) is suspended from the platform 12, being mounted on a pivot axle 42 fixed with respect to the platform to permit rotation along one axis to enable pivoting movement of the pendulum along the second plane P2, as shown in Figure 5. A second pivot 44 is fitted to a U-bracket 46 to enable the pendulum to move along the first plane Pl, as shown in Figure 4, enabling multidirectional movement of the pendulum as shown in Figure 6, and hence multidirectional level sensing. The pendulum can thus adapt a vertical orientation under gravity, regardless of the orientation of the apparatus.

Alternative pivot arrangements may be used to provide a multi-axis pivot such as a gimble bearing.

The pendulum 40 is of elongate form, with an enlarged diameter lower end portion 47, having two opposed outwardly extending flanges or hook portions 48,50.

The pendulum lower end portion 47 and the stop plate cutout portion 22 are dimensioned so that the end portion can pass through the cutout portion when the apparatus is oriented horizontally, e.g. being located on a horizontal surface, and the components adopt the position shown in Figures 1 to 3. However, when the apparatus is tilted, in any direction by more than a predetermined amount, pivoting of the pendulum, as represented in Figures 4 to 6, means that the upper surface of one of the hook portions 48,50 will engage one or more of the stop portions 24,26,28,30,32,34 on the underside of stop plate 20, as shown in Figure 6, preventing the lower end portion 47 of the pendulum from passing through the cutout portion 22 of the stop plate 20 and thus preventing elevation of the platform. Thus only a very limited extent of vertical movement of the platform with respect to the chassis (determined by the initial spacing of the hook portions 48,50 from the stop portions) will be possible, io and significant elevation of the platform will not be possible.

The arrangement thus acts as a tilt sensor and lock, preventing elevation of the platform in potentially unsafe conditions.

is The permitted angle of tilt, and hence the predetermined deviation from horizontal orientation of the apparatus is typically about 5°.

The geometry of the pendulum 40 and stop plate cutout 22 determine the extent of deviation from horizontal of the apparatus that will be tolerated and still permit passage of the pendulum end portion through the cutout and hence elevation of the platform. Where space permits, the length of the pendulum can be extended to give greater accuracy.

The components are typically made of steel.

Claims

1. A locking arrangement for apparatus having a first component and a second component moveable relative to each other in a vertical direction in use of the

5 apparatus, the locking arrangement comprising a first locking member fixed with respect to the first component and suspended so as to be pivotable under gravity, and a second locking member fixed with respect to the second component and having a stop portion that cooperates with the first locking member to permit relative movement of the first and second components in a vertical direction only when the io stop portion of the second locking member adopts a horizontal orientation or deviates therefrom by less than a predetermined amount.

2. An arrangement according to claim 1, wherein the second component is stationary, in use of the apparatus, with the second component being moveable.

3. An arrangement according to claim 1 or 2, wherein the first locking member is of elongate form.

4. An arrangement according to claim 1, 2 or 3, wherein the first locking member

20 includes an enlarged portion, typically at or near the lower end.

5. An arrangement according to claim 4, wherein the enlarged portion comprises one or more outwardly-extending flanges, projections, juts, protrusions, etc.

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6. An arrangement according to any one of the preceding claims, wherein the first locking member is suspended by means of a pivot arrangement.

7. An arrangement according to claim 6, comprising a first pivot arrangement that permits movement in a vertical plane about a horizontal axis.

8. An arrangement according to claim 7, comprising two orthogonal pivot arrangements.

9. An arrangement according to any one of the preceding claims, wherein the stop portion of the second locking member is defined by one or more edge portions of the second locking member.

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10. An arrangement according to claim 9, wherein the stop portion is defined by one or more edge portions of an opening in the second locking member.

11. An arrangement according to claim 10, wherein the opening comprises a slit, an aperture or a cutout etc.

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12. An arrangement according to claim 10 or 11, wherein the opening comprises a slit or aperture having a pair of opposed edges, with a cutout in each of the opposed edges.

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13. An arrangement according to claim 12, wherein the first locking member has an enlarged portion comprising a pair of opposed projections.

14. An arrangement according to any one of the preceding claims, wherein the predetermined amount of permitted deviation from horizontal is 5°, 10°, 15° or 20°.

15. An arrangement according to any one of the preceding claims for use with an with access platform having an elevating work platform, that is elevated in use with respect to a chassis.

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16. An arrangement according to claim 15, wherein the first component comprises an elevating work platform and the second component comprises a chassis.

17. A locking arrangement substantially as herein described with reference to, and as shown in, the accompanying drawings.

18. An access tower comprising a locking arrangement in accordance with any one of the preceding claims.

Intellectual

Property

Office

Application No: GB1620074.3 Examiner: Chris Bennett