GB2484083A

GB2484083A - Pivotable platform

Info

Publication number: GB2484083A
Application number: GB201016301A
Authority: GB
Inventors: Robert Stephens
Original assignee: Tata Steel UK Ltd
Current assignee: Tata Steel UK Ltd
Priority date: 2010-09-28
Filing date: 2010-09-28
Publication date: 2012-04-04
Also published as: GB201016301D0

Abstract

An apparatus has two base units (4,6 fig.1) and two pivot points (64,66,68) connected to a single platform 8, to accommodate any difference in height between the two base units (4,6), whilst maintaining the platform in an essentially horizontal position. The platform may find application in the loading and unloading of vehicles.

Description

ACCESS PLATFORM

Embodiments of the invention relate to a platform, and particularly, although not exclusively, relate to a platform suitable for providing access to vehicles.

Manual loading and unloading of goods vehicles, for example flatbed trucks, can be a difficult and often hazardous activity for workers. The raised height of the truck makes it awkward for workers who have to climb onto the back of the truck in order to remove goods. Furthermore, once onboard workers may be at risk of falling from the truck.

Employers have a duty of care to provide a safe working environment that reduces the risk of accidents, or injury through accidents. This duty extends to a requirement to provide appropriate safety equipment in the workplace.

It is currently known to provide inflatable cushions or bags at the side of vehicles in order to cushion the fall of a worker if they happen to fall from the truck. However, this can be hazardous in itself. For example, a worker may fall onto an inflatable cushion and then either rebound and fall onto the ground or rebound and impact the side of the truck. This can cause serious injury.

It is therefore desirable to provide an apparatus that allows vehicles to be unloaded safely.

According to a first aspect of the invention there is provided an access platform comprising a base comprising first and second base units, a platform pivotally coupled to the first base unit and pivotally coupled to the second base unit such that a difference in the elevation of the first base unit with respect to the second base unit is accommodated by pivoting of the platform with respect to the base units.

The platform may be pivotable with respect to the first and second base units about respective horizontal axes that are perpendicular to a direction of elongation of the platform.

The platform may be slidably coupled to the base such that the platform is slidable with respect to the base between a retracted position and an extended position.

The platform may be slidable in a lateral direction with respect to the base.

The platform may be slidable in a direction which is parallel to the pivot axes of the respective pivotal connections between the platform and the first and second base units. The platform may be elongate and the platform may be slidable in a direction which is substantially transverse to the direction of elongation of the platform.

The platform may be cantilevered with respect to the base. The platform may overhang a perimeter of the base, at least in the extended position.

The base may comprise means for accommodating ballast. The means for accommodating ballast may comprise means for removably accommodating ballast.

The means for accommodating ballast may be disposed such that ballast counterbalances the platform when in the platform is in the extended position.

The means for accommodating ballast may be suitable for accommodating an intermediate bulk container.

The platform may be slidably coupled to the base on at least one linear bearing. The platform may be slidably coupled to the base on spaced apart linear bearings. The linear bearings may be arranged such that a first end of the platform can be further forward than the second end.

The or each linear bearing may comprise a rail and a carriage. The rail may comprise an elongate channel defined by opposed side walls and a base.

The carriage may comprise a plurality of rollers that can roll/slide in the channel about an axis substantially perpendicular to the base. At least one of the side walls may comprise an elongate groove formed on an inner surface within which the rollers roll.

The cross-section of the or each groove may correspond to the shape of the circumferential surface of the or each roller. The cross-section of the groove may be substantially V-shaped.

The access platform may further comprise first and second sliders disposed between the platform and the respective first and second base units, the platform being pivotally coupled to each slider and each slider being slidably coupled on the respective first and second base units.

The access platform may further comprise a locking means for locking the platform in the extended position and/or the retracted position.

According to a second aspect of the invention there is provided an access platform comprising a base, and a platform slidably coupled to the base such that the platform is slidable with respect to the base between a retracted position and an extended position.

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:-Figure 1 is perspective view of an access platform; Figure 2 is a front view in section of the access platform shown in Figure 1; Figure 3 is a perspective view of a base unit of the access platform shown in Figure 1 in isolation; Figure 4 is an elevation view in section of the access platform shown in Figure 1 through a linear bearing; Figure 5 is a partial elevation view in section of the access platform in region J as shown in Figure 4; Figure 6 is a partial front view in section of the access platform in the region of the bearing; Figure 7 is a perspective view of the slider shown in Figure 1 in isolation; Figure 8 is an elevation view in section of the slider shown in Figure 7; Figure 9 is front view in section of the platform of the access platform shown in Figure 1 in isolation; Figure 10 is an elevation view in section of the access platform shown in Figure 1; Figure 11 is a partial elevation view in section of the access platform in region H as shown in Figure 10; Figure 12 is a perspective view of an access platform shown in Figure 1 in an extended position; Figure 13 is an elevation view in of the access platform shown in Figure 1 in a retracted position; and Figure 14 is an elevation view in of the access platform shown in Figure 1 in an extended position.

Figures 1 and 2 show an access platform 2 according to an embodiment of the invention comprising first and second base units 4, 6. a platform 8 mounted on and above the base units 4, 6 and first and second sliders 10, 12 disposed between the respective base units 4, 6 and the platform 8. The platform 8 is supported by the base units at an elevated height. The platform 8 is generally elongate in this embodiment and is supported at either end by one of the base units 4, 6. However, it should be appreciated that in other embodiments there may only be a single base unit that supports the platform 8, possibly substantially along the entire length of the platform 8.

ln the embodiment shown, the base units 4, 6 are identical but in other embodiments this may not necessarily be the case.

Figure 3 shows a single base unit 4, 6 of the access platform 2 of the embodiment shown in Figures 1 and 2. The base unit 4, 6 comprises a box-frame plinth 14 connected to a means for accommodating ballast 16 which is adjacent to, and rearward of, the plinth 14.

Each box-frame plinth 14 comprises a plinth base 18 and plinth top 20. The plinth base 18 and plinth top 20 are each constructed from two main beams 22 connected at their ends by cross-beams 24. Each plinth base 18 is connected at the corners to respective corners of the corresponding plinth top 20 by two front pillars 26 and two rear pillars 28. The rear pillars 28 of each plinth 14 extend upwardly from the plinth 14.

The means for accommodating ballast 16 comprises a support base 30 which is connected to, and extends rearward from, the plinth base 18. Struts 32 connect rearward corners of the support base 30 to the tops of the respective rear pillars 28 of the plinth 18 to form a truss arrangement on opposite sides of the base unit 4, 6. The support base 30, rear pillars 28 and struts 32 define a region of the base unit 4, 6 in which ballast can be received. The base unit 4, 6 is constructed from metal, for example steel, beams welded or bolted together. This provides a lightweight assembly having a good strength-to-weight ratio.

As shown in Figure 4, linear bearings 34 are fastened to each of the main beams 22 of the plinth top 20. Each base unit 4, 6 therefore has a linear bearing 34 on each side of the base unit 34. The linear bearings 34 are elongate and are parallel to one other and lie in a horizontal plane. The linear bearings 34 extend from the front of the base unit 4, 6 towards the rear.

The linear bearing 34 shown in Figure 4 is shown more clearly in Figures 5 and 6.

Each linear bearing 34 comprises a rail 36 and two carriages 38 arranged to slide along the rail 36. The rail 36 has a base 361 and opposing side walls 362 along each side of the base 361 which define a channel along the length of the rail 36. An elongate groove 363 is formed in the inwardly facing surface of each side wall 362 and extends along the length of the rail 36. Each groove 363 has a substantially V-shaped cross-section which converges towards the outer surface of the side wall 362. Each carriage 38 comprises three rolling elements 381 which are disposed along the length of the carriage 38. The rolling elements 381 are supported on the carriage 38 by spindles 382 which extend in a vertical direction that is perpendicular to the length of the carriage 38. Each rolling element 381 has a circumferential surface 383 which substantially corresponds to the shape of the grooves 363. The rolling elements 381 are arranged to engage the grooves 363 in the opposing side walls 362 so that the rolling elements 381 can roll along the grooves 363 in a forwards and backwards direction. The rolling elements 381 are thus held captive by the grooves 363 so that they are constrained to roll in the lengthwise direction of the rail 36. This allows the carriages 38 to side relative to the rail 36 in a forwards and backwards direction.

As shown in Figure 5, the linear bearings 34 support the sliders 10, 12 on the base unit 4, 6 so that they are between the respective base units 4, 6 and the platform 8.

A slider 10, 12 is shown in isolation in Figures 7 and 8. The slider 10, 12 comprises parallel beams 42 which are connected to each other at their respective ends by end beams 44. A slot 46 extends along the length of the upper surface of each beam 42.

A bore 48 extends through the mid portion of each of the beams 42 and extends across the slot 46. The bores 48 are coaxial and extend transversely with respect to the lengths of the beams 42. Two guides 50 are disposed in each slot 46. The guides 50 are disposed on opposite sides of the bore 48, between the bore 48 and the respective ends of the slider 10, 12.

The slider 10, 12 is fixed to both linear bearings 34 of a base unit 4, 6. Each beam 42 of the slider 10, 12 is secured by bolts, or other fastening means, to a respective carriage 38 of a linear bearing 34 on one side of the base unit 4, 6 and a corresponding carriage 38 on the opposite side of the base unit 4, 6. The slider 10, 12 can therefore slide in a forward/rearward direction with respect to the base unit 4, 6 on which it is mounted.

The platform 8 is shown in isolation in Figure 9. The platform 8 comprises an elongate floor 52, providing a walkway, bordered along one side and both ends by a barrier 54.

In the embodiment shown, the barrier 54 comprises multiple rails 56 supported between posts 58. The barrier 54 is interrupted along the side of the platform 8 by openings 60 between the posts 58, from which steps 61 ascend away from the floor 52 to provide access to the platform 8. The steps 61 are provided with support rails adjacent to the steps 61. The steps 61 are positioned centrally on the platform 8 so that when the platform 8 is mounted on the base units 4, 6, the steps 61 are inward of the base units 4, 6 and so do not interfere with the base units 4, 6 in use. The underneath of the floor 52 is supported by a supporting structure 62 which provides strength and flexural rigidity to the platform 8. In the embodiment shown, the supporting structure 62 is a framework comprising metal, for example steel, beams welded or bolted together.

Two sets of pivot plates 64 are rigidly connected to the supporting structure 62 underneath the floor 52, for example by a bolting arrangement or by welding. Each set of pivot plates 64 is spaced apart from the other set of pivot plates 64 in the lengthwise direction of the platform 8. Each set of pivot plates 64 is offset from the lengthwise centreline of the platform 8 towards the rear of the platform 8 (i.e. towards the barrier 54 along the side of the platform 8) as shown in Figure 10.

Each set of pivot plates 64 comprises two pivot plates 66 which are spaced apart from each other in the transverse direction of the platform 8. The pivot plates 66 are spaced so that they will align with the respective slots 46 provided in each of the beams 42 of the sliders 10, 12. The pivot plates 66 extend downwardly away from the floor 64. A bore 68 is provided through the lower portion of each pivot plate 66.

The platform 8 is mounted onto the sliders 10, 12 by slotting the sets of pivot plate 66 into the respective slots 46 in the sliders 10, 12 on each of the base units 4, 6. The arrangement of the pivot plates 66 with respect to the slider is shown in Figures 10 and 11. Each pivot plate 66 is accommodated within one of the slots 46 and between the guides 50 disposed in the slot. The guides 50 align each pivot plate 66 within the slot 46 so that the bores 48 of each slider 10,12 are coaxial with the bores 68 of the corresponding pivot plates 66. A pin or bearing arrangement 70 extends through the bores 48, 68 to secure the pivot plates 66 to the corresponding slider 10, 12. The pin or bearing arrangement 70 define pivot axes which are substantially horizontal and parallel to the sliding direction of the platform 8 (and therefore perpendicular to the elongate direction of the platform) about which the platform 8 pivots with respect to each of the base units 4, 6.

The platform 8 is thus able to pivot with respect to the each of the base units 4, 6 and slide from a retracted position above the base units 4, 6 to an extended position substantially forward of the base units 4, 6. The components of the linear bearings 34, for example the rolling elements 381, are toleranced to accommodate a small angle of rotation of the platform 8 in a horizontal plane. The linear bearings 34 can therefore be displaced forward by different amounts, thus allowing one end of the platform 8 to be moved further forward than the other end of the platform 8.

A locking mechanism, such as a drop pin arrangement, is provided for locking the platform 8 in the extended or retracted position.

In use, the base units 4, 6 of the access platform 2 are set on the ground; for example, adjacent an unloading/loading bay for a truck. If the ground is raised under one of the base units 4, 6 with respect to the ground underneath the other of the base units 4, 6, the pivotal connection between the platform 8 and the sliders 10, 12 allows the platform 8 to tilt to accommodate the difference in height between the base units 4, 6 without destabilising the access platform 2. The pivotal connection is suitable for accommodating a height difference between the base units of up to 500 mm. In addition, the bending or twist of the access platform does not lead to lock-up of the linear bearings 34.

A ballast, such as an Intermediate Bulk Containers (IBC) which is a container for storing and transporting liquid or powder, is placed on each support base 30 and between the struts 32 of the ballast retainer 16. The IBCs are then filled with water, for example, to provide ballast at the rear of the access platform 2 so as to resist displacement and counterbalance forward tipping of the access platform 2. The IBCs may be 1000 litre capacity containers which when filled with water provide approximately 1 tonne of ballast.

Figures 1 and 10 show the access platform 2 in situ on level ground. The platform 8 is in a retracted position in which the platform 8 is supported over the central region of each of the base units 4, 6. A truck can be manoeuvred into position alongside the side of the platform 8 not having the barrier 54. The truck, or trailer, should be approximately level with the edge of the floor 52 of the platform 8, but spaced away from the platform 8 so as to leave a lateral gap between the truck/trailer and the platform 8.

The platform 8 is then pushed forward, for example by a person positioned between the steps 61 (although actuators may be provided), to slide the platform 8 forward on the sliders 10, 12 towards the truck/trailer. The steps 61 pass between the base units 4, 6 and so do not obstruct forward motion of the platform 8. The offset attachment of the platform 8 with the sliders 10, 12, means that the platform 8 extends forward of the base units 4, 6 when moved to its forward position and overhangs the front of the base units 4, 6. In this extended position, as shown in Figures 12 and 14, the lateral gap between the truck/trailer and the floor 52 is reduced significantly or eliminated completely. The tolerance in the bearings 34 allows for the ends of the platform 8 to be pushed forward by different amounts. The linear bearings 34 thus allow for one end of the platform 8 to slide further forward than the other without causing locking of the linear bearings 34. Consequently, the platform 8 can be aligned with a side of the vehicle even when the vehicle is not perfectly aligned with the lengthwise direction of the access platform 2. For a platform 8 which is 12,000 mm in length, the maximum difference in forward displacement of one end of the platform 8 with respect to the other end of the platform 8 is approximately 50 mm.

The IBCs counter the increased moment exerted by the overhanging platform 8 to prevent the access platform 2 toppling forward. The platform 8 is locked with respect to the base units 4, 6 in the extended position using the locking mechanism.

The access platform 2 provides a safe working environment when unloading or loading a truck/trailer by providing a raised platform 8 having with an integral barrier 54 adjacent the trailer from which to load/unload the truck. Access to the platform 8 is provided through the openings 60 via the steps 61.

The ballast provided by the IBC5 (or similar) can be set to prevent the access platform 2 from toppling forward even in the extended position. The sliding motion enables the base units 4, 6 to remain static 2 whilst enabling a gap between the floor 52 of the platform 8 and the truck/trailer to be closed without excessive manoeuvring of the truck.

In addition, the access platform 2 provides easy access to the trailer by way of the steps6l.

Once loading/unloading of the truck has been completed, the locking mechanism is unlocked and the platform 8 is pulled to slide the platform 8 away from the truck. The truck is thus able to manoeuvre away from the platform 2 unimpeded.

The access platform 2 may be staked to the ground rather than, or in addition to, providing ballast.

The platform 8 need not have steps 61, or may have one or more than two flights of steps 61. Steps may descend from the ends of the platform 8 in a plane parallel to the length of the platform 8.

The platform 8 may be of any length and may, for example, be 12m, lOm, 8m or 6m in length.

In a variant of the invention, the linear bearings 34 may be arranged perpendicularly to the arrangement shown in the drawings. The rolling axes of the rolling elements 381 are thus substantially parallel to the upright direction of the base units 4,6 on which linear bearings are mounted, The base units 4, 6 may comprise other suitable load bearing units such as concrete plinths or similar.

It will be appreciated that the sliding and pivotal connections between the base units 4, 6 and the platform 8 may be utilised independently of each other. For example, the base may be a single base that is generally coextensive with the platform, with respect to which the platform can slide. This can be used where there is no requirement to accommodate a difference in height between opposite ends of the platform.

Alternatively, first and second base units may be provided at either end of the platform without a sliding arrangement, the platform being pivotally connected to each base unit.

The sliding arrangement (e.g. linear bearings) is therefore not provided. The base units may, for example, be mounted on wheels which allow for the access platform to be wheeled into position. The platform can then pivot with respect to each base unit to accommodate for a change in height.

Claims

CLAIMS1. An access platform comprising: a base comprising first and second base units; a platform pivotally coupled to the first base unit and pivotally coupled to the second base unit such that a difference in the elevation of the first base unit with respect to the second base unit is accommodated by pivoting of the platform with respect to the base units.
2. An access platform as claimed in claim 1, wherein platform is pivotable with respect to the first and second base units about respective horizontal axes that are perpendicular to a direction of elongation of the platform.
3. An access platform as claimed in claim 1 or 2, wherein the platform is slidably coupled to the base such that the platform is slidable with respect to the base between a retracted position and an extended position.
4. An access platform as claimed in claim 3, wherein the platform is slidable in a lateral direction with respect to the base.
5. An access platform as claimed in claim 4, wherein the platform is slidable in a direction which is parallel to the pivot axes of the respective pivotal connections between the platform and the first and second base units.
6. An access platform as claimed in claim 4 or 5, wherein the platform is elongate and the platform is slidable in a direction which is substantially transverse to the direction of elongation of the platform.
7. An access platform as claimed in any one of the preceding claims, wherein the platform is cantilevered with respect to the base.
8. An access platform as claimed in any one of the preceding claims, wherein the platform overhangs a perimeter of the base, at least in the extended position.
9. An access platform as claimed in any one of the preceding claims, wherein the base comprises means for accommodating ballast.
10. An access platform as claimed in claim 9, wherein the means for accommodating ballast comprises means for removably accommodating ballast.
11. An access platform as claim in claim 9 or 10, wherein the means for accommodating ballast is disposed such that ballast counterbalances the platform when in the platform is in the extended position.
12. An access platform as claimed in any one of claims 9 to 11, wherein the means for accommodating ballast is suitable for accommodating an intermediate bulk container.
13. An access platform as claimed in any one of the preceding claims, wherein the platform is slidably coupled to the base on at least one linear bearing.
14.An access platform as claimed in claim 13, wherein the platform is slidably coupled to the base on spaced apart linear bearings.
15.An access platform as claimed in claim 14, wherein the linear bearings are arranged such that a first end of the platform can be further forward than the second end.
16. An access platform as claimed in any one of claims 13 to 15, wherein the or each linear bearing comprises a rail and a carriage.
17. An access platform as claimed in claim 16, wherein the rail comprises an elongate channel defined by opposed side walls and a base.
18. An access platform as claimed in claim 17, wherein the carriage comprises a plurality of rollers that can roll/slide in the channel about an axis substantially perpendicular to the base.
19. An access platform as claimed in claim 18, wherein at least one of the side walls comprises an elongate groove formed on an inner surface within which the rollers roll.
20. An access platform as claimed in claim 19, wherein the cross-section of the or each groove corresponds to the shape of the circumferential surface of the or each roller.
21. An access platform as claimed in claim 20, wherein the cross-section of the groove is substantially V-shaped.
22. An access platform as claimed in any one of claims 3 to 21, further comprising first and second sliders disposed between the platform and the respective first and second base units, the platform being pivotally coupled to each slider and each slider being slidably coupled on the respective first and second base units.
23. An access platform as claimed in any one of the preceding claims, further comprising a locking means for locking the platform in the extended position and/or the retracted position.
24. An access platform substantially as described herein with reference to, and as shown in, the accompanying drawings.