GB2419373A

GB2419373A - Foldable access platform

Info

Publication number: GB2419373A
Application number: GB0423412A
Authority: GB
Inventors: Gary Frank Clubb
Original assignee: Youngman Group Ltd; SGB Services Ltd
Current assignee: Youngman Group Ltd
Priority date: 2004-10-21
Filing date: 2004-10-21
Publication date: 2006-04-26
Anticipated expiration: 2024-10-21
Also published as: GB2419373B; GB0423412D0

Abstract

An access platform comprises a support structure (1) having a first part (2) telescopically engaged with a second part (3) such that the second part (3) can be moved horizontally relative to the first part (2). The access platform is provided with a ladder frame (21) and a support frame (26). Each frame is pivotally connected at one end to the first part (2) and pivotally connected at the other end to a platform unit (29) such that the platform unit (29) can be moved from a position adjacent the support structure (1) to an elevated, horizontal position. A connection frame (25) is provided pivotally connected at one end to the support frame (26) and pivotally connected at the other end to the second part (3) such that the raising of the platform unit (29) above the support structure (1) causes the second part (3) to move horizontally towards the first part (2). A locking pin (20) is provided to lock the platform unit (29) at the desired level.

Description

241 9373

DESCRIPTION OF INVENTION

"IMPROVEMENTS IN OR RELATING TO AN ACCESS PLATFORM" THE PRESENT INVENTION relates to an access platform, and more particularly relates to an access platform to provide low level access.

There is a requirement for a low level access platform that is easy to transport, easy to assemble and easy to use.

The present invention seeks to provide an improved low level access platform.

According to the present invention there is provided an access platform, the access platform comprising: a support having a first part and a second part, said second part being substantially horizontally moveable relative to the first part; a pivotable frame pivotally mounted to the first part and moveable between a substantially horizontal storage position and at least one in-use position which is raised with respect to said storage position, a connection element being provided connecting said frame to the second part such that pivotal movement of the pivotable frame causes horizontal movement of the second part relative to the first part; an access platform unit being provided and being configured to engage the frame such that when the frame is in the or each in-use position the platform unit adopts an elevated position relative to said support.

Preferably, a locking means is provided configured to releasably lock the frame in the or each in-use position. s

Conveniently, said first part telescopically engages said second part.

Advantageously, said locking means is configured to releasably lock said telescopically engaged first and second parts relative to one another.

Preferably, said locking means comprises one or more locking apertures or recesses provided in one of said first and second parts, and a locking pin provided on the other of said parts, the locking pin being releasably engageable in the or each said aperture or recess. ]5

Conveniently, said locking means comprises a plurality of said locking apertures or recesses, each said locking apertures or recess corresponding to discrete and respective said in-use positions.

Advantageously, the locking pin is biased towards engagement with the or each said locking aperture or recess.

Preferably, said locking means further comprises a release element operable to move the locking pin against said bias.

Conveniently, said release element takes the form of a foot pedal.

Advantageously, a further frame is provided pivotally mounted to the first part.

Preferably, the platform unit is pivotally connected to both of said frames.

Conveniently, said frames are configured such that said platform unit remains substantially horizontal as said pivotable frame is moved between said storage position and the or each said in-use position.

Advantageously, the or each frame comprises a pair of substantially parallel stiles.

Preferably, the or at least one of said frames is provided with at least one cross-member extending between the stiles.

I 5 Conveniently, the or at least one of said frames is a ladder frame comprising a plurality of said cross-members in the form of rungs.

Advantageously, the connection element comprises a strut pivotally connected at one end to the pivotable frame and pivotally connected at the other end to the second part.

Preferably, said connection element comprises a pair of substantially parallel struts interconnected by at least one cross-member.

Conveniently, the or each strut is connected to one of the cross-members of the or each respective frame.

Advantageously, the first part and the second part are each provided with at least one support formation configured to engage with the ground to support the access platform.

Preferably, the or each support formation provided on at least one of said first and second parts, is mounted on a moveable outrigger configured for movement along an axis substantially perpendicular to the axis of said horizontal movement of the second part relative to the first part.

Conveniently, at least one said support formation comprises a castor.

Advantageously, the platform unit is provided with a collapsible structure comprising a guard rail configured to extend at least partially around a person standing on the platform unit, said collapsible structure allowing movement of the guard rail between a storage position substantially adjacent the platform unit and an operational position raised above the platform unit.

Conveniently, when the guard rail is in said operational position it remains at the same raised height above the platform unit for any elevated position of the platform unit relative to said support.

Preferably, the collapsible structure is configured such that said guard rail remains substantially horizontal as it is moved between its storage position and its operational position.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a perspective view of an access platform in accordance with the present invention having a platform unit, the platform unit being illustrated in an intermediate in- use position; FIGURE 2 is a perspective view of the access platform of figure 1, showing the platform in an alternate, storage position, and a collapsible guard rail structure in a partially collapsed state; lO FIGURE 3 is a perspective view of the access platform, showing the platform unit in a storage position; and the guard rail in an in-use position; FIGURE 4 is a perspective view of the access platform, showing the platform unit in a fully elevated in-use position; FIGURE S is a perspective view of part of the access platform showing part of a locking means; and FIGURE 6 is a perspective view part of the access platform showing another part of the locking means.

Referring initially to Figure 1 of the accompanying drawings the access platform according to the present invention comprises a support structure 1 having a first part 2, and a second part 3.

The first part 2 takes the form of a frame comprising a pair of elongate base tubes 4, 5 which are parallel and spaced apart from one another. Each base tube 4, 5 has a free end 6 and an engagement end 7. The base tubes 4, S. are interconnected towards their free ends 6 by a first a transverse pivot tube 8 and by a transverse base tube 9, the transverse base tube 9 being nearer the free end 6 of each base tube 4, 5 than the first transverse pivot tube 8. Both the first transverse pivot tube 8, and the transverse base tube 9 extend between the base tubes 4, 5, and therefore lie in the same plane as the base tubes 4, 5. The engagement ends 7 of the base tubes 4, 5 are interconnected by means of a second transverse pivot tube 10.

The second part 3 of the support structure 1 also takes the form of a frame and comprises a pair of elongate extension tubes 13, 14 which are parallel and spaced apart from one another. Each extension tube 13, 14 has a free end 15 and an engagement end 16. The extension tubes 13, 14 are interconnected near their free ends 15 by a third transverse pivot tube 17 which extends between the extension tubes 13, 14 such that it lies in the same plane as the extension tubes 13, 14.

The external diameter of each extension tube 13, 14 of the second part 3 is slightly less than the internal diameter of each base tube 4, 5 of the first part 2 to enable the engagement end 16 of each extension tube 13, 14 to be telescopically received within the engagement end 7 of a respective base tube 4, 5, preferably as a close-sliding-fit. It should therefore be appreciated that the first part 2 of the support structure 1 is telescopically engaged with the second part 3 so that the two parts are horizontally moveable relative to each other in the same plane. It is envisaged that nylon bushes could be provided at the ends of the extension tubes 13, 14 and the base tubes 4, 5 to improve the sliding fit between the telescopically engaged tubes.

The free end 6 of each base tube 4, 5 is provided with a support formation in the form of a castor 18 of a type which is well known per se. The castors 18 are configured for engagement with the ground so as to maintain the plane of the support structure 1 at a position spaced from the ground.

The free ends 15 of the second part 3 are provided with an outrigger arrangement which comprises a transverse stabiliser tube 11 which is a substantially elongate tube of rectangular cross-section. The transverse stabiliser tube 11 is fixedly mounted to the third transverse pivot tube 17 by means of a pair of mounting brackets in a position substantially adjacent the free ends 15 of the second part 3 and substantially parallel with the third transverse pivot tube 17.

A pair of stabiliser clamps 12 are provided at positions substantially adjacent the respective ends of the transverse stabiliser tube 11. Each stabiliser clamp 12 comprises a bolt which has a handle at one end and which is threadedly engaged with an aperture through the wall of the [ransverse stabiliser tube 11 at the other end.

A pair of elongate outriggers 11 a are provided, each of which comprises an substantially elongate tube of rectangular cross-section and which is sized and shaped to enable it to be telescopically received within a respective end of the transverse stabiliser tube 11, preferably as a close sliding fit as illustrated most clearly in Figure 2. The outer end of each outrigger 1 la is also provided with a support formation in the form of a castor 18. It is to be appreciated that because both the stabiliser tube 11 and each outrigger lla are rectangular in cross- section and are in sliding engagement with each other, the outrigger 1 la is prevented from rotating relative to the transverse stabiliser tube 11 such that the castor 18 at the end of the outrigger 1 la is maintained in substantially the same orientation relative to the ground for any extension of the outrigger 1 la from the transverse stabiliser tube 11. It is further to be appreciated that each outrigger lla can be telescopically extended outwardly from the transverse stabiliser tube 11 along an axis substantially perpendicular to the axis along which the extension tubes 13, 14 move relative to the base tubes 3, 4. The outriggers 11 a can also each be locked in position by twisting the handle of its respective stabiliser clamp 12 such that the end of the bolt of the stabiliser clamp 12 bears against the outer surface of the outrigger lla within the stabiliser tube 11.

The castors 18 enable the support structure 1 to be manoeuvred over the ground and are each provided with a castor-wheel-lock 19 (again of a type known per se) to lock the wheel of each castor 18 once the support structure 1 has been moved to the desired location, thereby preventing subsequent movement of the support structure 1 relative to the ground.

It is to be appreciated that by virtue of the telescopic engagement of the extension tubes 13, 14 of the second part 3 with the respective base tubes 4, 5 of the first part 2, the effective "footprint", defined by a line bounding the points of contact of each castor 18 in engagement with the ground, can be increased, or reduced.

Furthermore, extension of the outriggers 1 la from the transverse stabiliser tube 11 increases the lateral distance between the points of contact of the castors 18 at the ends of each outrigger 1 la such that the lateral stability of the access platform can be further improved. It is also envisaged that such a outrigger arrangement could be provided at the free ends 6 of the base tubes 4,5 of the first part 1.

In the region of the engagement ends 7 of the base tubes 4, 5 there is provided a locking means 20 which is configured to lock releasably the first part 2 of the support structure 1 to the second part 3 of the support structure l, so as to prevent the first and second parts 2, 3 moving relative to one another once a desired "footprint" has been set. The locking means 20 will be described in more detail hereinafter.

A pivotable ladder frame 21 is provided which comprises a pair of spaced apart, and parallel stiles 22, 23 interconnected by a plurality of transverse cross-members 24 in the form rungs. The lower end of each stile 22, 23 is pivotally connected to the first transverse pivot tube 8 of the first support part 2, such that the ladder frame 21 is moveable between a substantially horizontal storage position, and a substantially vertical, fully elevated in-use position. Figure 1 shows the ladder frame in an intermediate position between said storage position and said fully elevated position.

A pivotable support frame 26 is also provided which comprises a pair of spaced apart and substantially parallel support struts 27, 28, each of which is substantially the same length as the stiles 22, 23 of the ladder frame 21. The support struts 27, 28 are interconnected by a cross-member located at a point intermediate their ends. The support struts 27, 28 are pivotally connected at their lower ends to the second transverse pivot tube 10. Hence, the support frame 26 can also be moved between a substantially horizontal storage position and a substantially vertical, fully elevated in-use position.

A connection element 25 is provided which comprises a pair of substantially parallel struts 25a which are each interconnected by one, or preferably two, cross-members and which are pivotally connected at one end to the transverse cross-member of the support frame 26. The struts 25a are pivotally connected at their other ends to the third transverse pivot tube 17 of the second part 3 of the support structure 1.

A platform unit 29 is provided which comprises a generally square, planar platform. One side of the platform unit 29 is pivotally connected to the free ends of the support struts 27, 28 of the support frame 26, and the other, opposed, side of the platform unit 29 is pivotally connected to the free ends of the stiles 22, 23 of the ladder frame 21. The platform is dimensioned such that the point of connection between each support strut 27, 28 and the platform is spaced from the point of connection between a corresponding stile 22, 23 and the platform by a distance equal to the spacing between the second transverse pivot tube 10 and the first transverse pivot tube 8. Thus, the platform unit 29 remains substantially horizontal and parallel to the plane of the support structure 1, throughout the complete range of movement of the ladder frame 21 and the support frame 26.

A lifting handle bar 29a is provided which takes the form of an elongate tube which is transversely mounted to the under surface of the platform unit 29 in a position substantially adjacent the pivotal connections of the free ends of the stiles 22, 23 of the ladder frame 21 to the platform unit 29. The free ends of the lifting handle bar 29a each extend a short distance out from respective sides of the platform unit 29 to provide a convenient lifting handle for the user of the access platform. The lifting handle bar 29a also serves a support function which will be described in more detail hereinafter.

The platform unit 29 also has a collapsible guard structure 30 mounted on top of it which comprises a first guard frame 31 and a second guard frame 32. The first guard frame 31 comprises a pair of spaced apart guard posts 33, 34 which are parallel with each other and are interconnected by a transverse top guard rail 35, and by a transverse intermediate guard element 36, the intermediate guard element 36 being spaced below the top guard rail 35. The lower ends of the guard posts 33, 34 are each pivotally connected to a respective corner of the platform unit 29 on the same side of the platform unit 29 as the pivotal connection of the support struts 27, 28 of the support frame 26. The first guard frame 31 is thus pivotally moveable relative to the platform unit 29 between a substantially horizontal position and a substantially vertical position.

The second guard frame 32 also has a pair of spaced apart guard posts 37, 38 which are parallel with each other and which are substantially the same length as the guard posts 33,34 of the first guard frame 31. The guard posts 37, 38 are selectively interconnected by a gate 39 which is hingedly connected to one of the guard posts 37 and which is provided with a locking arrangement configured to engage and lock with the other guard post 38. The lJckir arrangement will be described in more detail hereinafter. The top of the gate 39 defines a second transverse guard rail 40a at the top of the guard posts 37, 38.

The bottom of the gate 39 defines a lower transverse guard element 40b. The lower ends of the guard posts 37, 38 are each pivotally connected to a respective corner of the platform unit 29 on the same side of the platform unit 29 as the pivotal connection to the ladder frame 21. The second guard frame 32 is thus also pivotally moveable relative to the platform unit 29 between a substantially horizontal position and a substantially vertical position.

The tops of the two guard frames 31, 32 are interconnected by way of a pair of spaced apart rail elements 41, 42, each rail element 41, 42 being pivotally connected at one end to the top of a respective post of the first guard frame 31, and being pivotally connected at the other end to the top of a respective post of the second guard frame 32. The first transverse guard rail 35, the second transverse guard rail 40a, and the rail elements 41, 42 together define a peripheral guard rail 43 extending around the platform at a convenient height to provide protection to a person standing on the platform.

The locking arrangement for the gate will now be described in more detail. The gate 39 is hingedly connected to one of the guard posts 37 by means of a pair of spaced apart cylindrical collars slidably engaged with the outer surface of the guard post 37. The lower collar is provided with two notches (not shown) along its lower edge which are diametrically opposed to each other on an axis substantially perpendicular to the plane of the gate 39. The free end of the second transverse guard rail 40a, defining the top of the gate 39, terminates in a downwardly projecting button 40c.

Thus, the collars enable the gate 39 to be rotated about the longitudinal axis of the guard post 37 as well as be moved axially along the guard post 37.

The gate 39 is prevented from moving downwardly along the guard post 37 by means of a retaining pin (not shown) which extends diametrically through the guard post 37 on an axis which preferably makes an angle of substantially 20 to the plane of the second guard frame 32, and which bears against the lower edge of the lower collar. A helically wound compression spring is provided on the guard post 37 between the upper edge of the lower collar and a flange on the guard post 37 to bias the lower edge of the lower collar against the retaining pin.

Therefore, it is to be appreciated that when the gate 39 is in the open position, the notches in the lower collar are aligned, and engaged with the retaining pin such that the gate 39 is held open. Furthermore, it is to be appreciated that because the axis of the retaining pin makes an angle of substantially 20 to the plane of the second guard frame 32, the plane of the gate 39 is substantially 110 to the plane of the second guard frame 32 when held in the fully open position. To close the gate 39, the user must lift the gate 39 upwardly against the bias of the compression spring to release the retaining pin from the notches and enable the gate 39 to be swung towards its closed position. When the planes of the gate 39 and second guard frame 32 are substantially coplanar, the user can release the gate 39 to enable it to move downwardly such that the downwardly projecting button 40a engages with a corresponding recess in the other guard post 38 to lock the gate 39 in the closed position. The other guard post 38 may also be provided with a backstop to prevent the gate from swinging too far inwards when being moved from the open position to the closed position.

The collapsible guard structure 30 is configured such that the point of connection between each guard post 33, 34 and the platform unit 29 is spaced from the point of connection between a corresponding guard post 37, 38 and the platform unit 29 by a distance equal to the spacing between the pivotal connections of each rail element 41, 42. Thus, the guard rail 43 remains substantially horizontal and parallel to the plane of the platform unit 29, throughout the range of pivotal movement of the first guard frame 31 and the second guard frame 32 relative to the platform unit 29.

The collapsible guard structure 30 is also provided with pair of hinged struts 44, 45, each of which is hinged at a point intermediate its end so that it may be locked in a linear position. Each strut 44, 45 is pivotally connected at its upper end to a respective rail element 41, 42 near its pivotal connection with the top of the first guard frame 31, and is pivotally connected at its lower end to the platform unit 29 adjacent the pivotal connection of the respective guard post 37, 38 of the second guard frame 32.

Referring now to Figure 2, the collapsible guard structure 30 is shown in a partially collapsed state. It can be seen that upon the unlocking of the hinged Struts 44, 45, the guard frames 31, 32 can be moved from a substantially vertical in-use position, towards a substantially horizontal storage position (not shown) in which the guard rail 43 is located substantially adjacent the platform unit 29, and over the first part 2 of the support structure.

The way in which the access platform can be used will now be described.

Referring to Figure 3, it can be seen that when the ladder frame 21 is in its substantially horizontal storage position, the platform unit 29 lies substantially parallel with and adjacent the plane of the support structure l.

The under surface of the lifting handle bar 29a bears against the support struts 27, 28 of the support frame 26 to space the under surface of the platform unit 29, in the region of the free ends of the stiles 22, 23 of the ladder frame 21, from the support struts 27, 28 to ensure that the platform unit 29 remains substantially parallel with the plane of the support structure 1 when a person stands on the platform unit 29 in this storage position. It will be noted that in this storage position the first part 2 and the second part 3 of the support structure are fully horizontally extended away from each other such that the "footprint" defined by the castors is maximised. Figure 3 also shows that the collapsible guard structure 30 has been moved to its substantially vertical in-use position with the hinged struts 44, 45 locked in their linear positions so that the guard rail 43 extends around the platform at a convenient height above the platform unit 29 in readiness to provide protection to a person standing on the platform.

Referring now back to Figure 1, it can be seen that the platform unit 29 may be raised by the user by means of conveniently grasping one or other of the lifting handles at the ends of the lifting handle bar 29a, to a desired jr-use elevated position above the support structure 1, and that as the platform unit 29 is raised relative to the support structure 1, the ladder frame 21 pivots about the first transverse pivot tube 8, and the support frame 26 pivots about the second transverse pivot tube 10, such that the platform unit 29 remains horizontal and parallel with the plane of the support structure 1. It can also be seen that as the support frame 26 pivots about the second pivot tube 10, the extension tubes 13, 14 of the second part 3 are slidably moved into the corresponding base tubes 4, of the first part 2 by virtue of the pivotal connection of the connection element 25 between the cross-member of the support frame 26 and the third transverse pivot tube 17 of the second part 3, such that the "footprint" is reduced. Subsequent locking of the first part 2 relative to the second part 3, by virtue of the locking means 20, not only locks the support frame 26 in a fixed pivotal position relative to the support structure 1, it also, therefore, locks the platform unit 29 at the desired elevated position above the support structure 1.

It is to be appreciated that the user can then gain access to the raised platform unit 29 from the ground by means of the first transverse base tube 9 of the first part 2 and the rungs provided by the transverse crossmembers 24 of the ladder frame 21, climbing the ladder frame in much the same way as a conventional ladder. Once the user is standing on the platform unit 29, the gate 39 of the second guard frame 32 can be closed such that the guard rail 43 extends completely around the user to prevent he or she from falling off the platform unit 29. Although Figure 4 shows a person climbing the ladder frame 21 in a substantially vertical orientation, it is envisaged that in variants of the invention, the ladder frame 21, in its fully raised position will make an angle of approximately 70 to the horizontal. This will present a more convenient climbing angle for a user of the platform.

The access platform may also be provided with biasing means in the form of a helically wound tension spring connected to each side of the support structure (not illustrated). Each spring is attached at one end to a projection formed on a base tube 4, 5 and at the other end to a projection formed on the respective extension tube 13, 14 engaged with the base tube 4, 5. It is therefore to be appreciated that when the platform unit 29 is in its lowest, storage position, the extension tubes 13, 14 are in their fully extended horizontal position, and so these springs would adopt their fully extended state. When in this extended state, the force applied by the tension in the springs may be sufficient to overcome, or significantly counter, the force due to the combined weight of the platform unit 29, and the collapsible guard structure 30, hence assisting the user in raising the platform unit 29 to a raised operational position.

Alternatively, it is envisaged that the biasing means could be located entirely within an extension tube 13, 14 engaged with a respective base tube 4, 5, with its ends being connected to projections formed on the inner surfaces of the respective tubes, such that the biasing means is protected from damage and the ingress of dirt and damage. It is of course to be appreciated that the biasing means could be attached between other parts of the support structure 1, such as, for example, between the second and third transverse pivot tubes 10, 17, or between other parts of the access platform to assist in its raising, and that the biasing means could take the form other elastic, force storing elements.

Figure 4 shows the platform unit 29 at its maximum elevation relative the support structure 1, with the ladder frame 21 located at a position in which it extends upwardly at an angle of substantially 90 degrees relative to the support structure 1. It will be noted that in this in-use position the first part 2 and the second part 3 are horizontally retracted to their fullest extent relative to each other such that the "footprint" is minimised.

The locking means 20 which is configured to lock releasably the first part 2 relative to the second part 3 will now be described in detail, with particular reference to figures 5 and 6.

Each extension tube 13, 14 is provided with a plurality of apertures or recesses 46, 47 along its length which extend inwardly from its outer surface.

Each base tube 4, 5 is provided with an aperture 48, 49 which is configured for selective alignment with each aperture or recess 46, 47 of the extension tubes 13, 14. A pair of locking pins 50, 51 are provided, each of which is configured to extend from the outer surface of a respective base tube 4, 5, through its aperture 48, 49, and engage with one of the apertures or recesses 46, 47 on the corresponding extensiontube 13, 14 to lock the first part 2 relative to the second part 3.

In order to facilitate the simultaneous locking of the locking pins 50, 51 in each base tubes 4, 5 with the respective apertures or recess 46, 47 in the respective extension tubes 13, 14, the locking pins 50, 51 are interconnected by means of a transverse locking element 52 which extends transversely between the base tubes 4, 5. The transverse locking element 52 comprises a bar having an upwardly directed tab 53 (see Figure 5) at one end and an upwardly directed pressure plate 54 (see Figure 6) at the other end. An upper end of the tab 53 is connected to one of the locking pins 50, and the pressure plate 54 is connected to the other locking pin 51. The locking pins 50, 51 are aligned such that transverse movement of the locking element 52 moves each locking pin 50, 51 in or out of its respective aperture 48, 49 in the base tube 4, 5. The locking element 52 is provided with a biasing means such as a spring (not illustrated) which is configured to bias the locking pins 50, 51 towards engagement with their respective apertures or recesses 46, 47 in the extension tubes 13, 14.

A foot pedal 55 is also provided which comprises a pair of spaced apart and substantially parallel arms 56 which are interconnected at their lower ends by a transverse pedal bar 57. The upper end of each arm 56 is pivotally connected to the base tube 4 by means of a collar 58 rotatably engaged with the outer surface of the base tube 4 such that the foot pedal 55 is able to pivot about the longitudinal axis of the base tube 4. The collars 58 may be interconnected by a spacer element to ensure that the arms 56 remain parallel with one another.

The upper end of each arm forms a cam 59 which is fixed to a respective collar 58 and which is configured to bear against the pressure plate 54.

Therefore, pressure applied by the foot of the user against the foot pedal causes it to rotate about the longitudinal axis of the base tube 4 and cause ] 5 the cams 59 to urge the pressure plate 54 away from the base tube 4, thereby moving the transverse locking element 52 transversely, against the bias of the biasing means, and simultaneously disengaging the locking pins 50, 51 from their respective apertures or recesses 46, 47 on the extension tubes 13, 14. The extension tubes 13, 14 are then free to move telescopically within the base tubes 4, 5 such that the platform unit 29 can be moved to a discrete elevational position above the support structure 1. Subsequent removal of pressure from the foot pedal 55 enables the bias of the biasing means to drive the locking pins 50, 51 towards engagement with the apertures or recesses 46, 47.

Therefore, it is to be appreciated that the platform unit 29 can be raised by the user to the desired elevation relative to the support structure 1 when the foot pedal 55 is depressed, and upon the removal of pressure from the foot pedal 55, the locking pins 50, 51 are free to engage with a respective aperture or recess 48, 49 in the extension tubes 13, 14, thus locking the platform un t 29 at the desired elevation relative to the support 1.

It is to be appreciated that because the extension tubes 13, 14 are provided with a plurality of apertures or recesses 46, 47 along their length, each locking pin 50, 51 can be engaged with any one of the apertures or recesses 46, 47 such that the first part 2 can be locked relesably relative to the second part 3 in any one of a plurality of discrete horizontal positions. Therefore, by virtue of the support frame 26 being coupled to the first and second parts 2, 3, the support frame 26 is also locked in any one of a plurality of discrete angular in- use positions which corresponds with any one of a plurality of discrete elevated positions of the platform unit 29 relative to the support structure 1.

It envisaged that at least one of the extension tubes 13 could be provided lS with an alignment gauge in the form of a series of visual markers (not illustrated) provided at spaced apart positions along the longitudinal axis of the extension tube 13. The markers would be preferably located at an angular orientation of substantially 90 to the positions of the apertures or recesses 46 of the extension tube 13 so that the markers can be easily seen from above by ( the user of the access platform. Each marker would be spaced along the extension tube 13 such that when it is aligned with the edge of the engagement end 7 of the base tube 4, a corresponding pair of the apertures or recesses 46, 47, are aligned with the locking pins 50, 51. In this way, the user can determine when to release the foot pedal 55 to ensure effective locking of the extension tubes relative to the base tubes. Preferably each marker takes the form of an indicator hole formed in the outer surface of the extension tube 13 which may be filled with a highly visible coloured plug, but it is to be appreciated that other forms of indicia could be used.

It is to be appreciated that the above locking means 20 constitutes one of many possible ways in which the first support part 2 may be locked relative to the second support part 3. Other convenient locking mechanisms could be used without departing from the scope of the invention. Indeed, such locking mechanisms, instead of locking the first support part 2 relative to the second support part 3 could instead be configured to lock the support frame 26 or the ladder frame 21 in discrete angular positions relative to the first support part 2.

Such a locking mechanism would also be effective in locking the platform in discrete raised positions.

It is to be appreciated that the foot pedal 55 could be mounted to base tube 5 instead of base tube 4, and the gate 39 could be pivotally mounted to guard post 38 instead of guard post 37, such that the user could operate the access platform and gain access to the platform unit 29 from the other side of the access platform.

Whilst the embodiments discussed above describe an access platform which has platform unit 29 coupled to a telescopically extendible support structure 1, such that the raising or lowering of the platform unit 29 corresponds with a respective increase or decrease of the "footprint", an arrangement is also envisaged in which the platform unit 29 is not coupled in this manner to the support structure 1. This would enable the 'footprint" of the telescopically extendible support structure to be increased or decreased independently of the raising or lowering of the platform unit 29.

It is to be appreciated that when the access platform unit 29 is locked in a raised position above the support structured by means of the locking means 20, an inadvertent knock to the foot pedal 55, or any other part of the locking means 20, may be sufficient to disengage the locking pins 50, 51 from the respective apertures or recesses 46, 47 such that the platform unit 29 collapses.

Therefore, it is envisaged that some sort of safety catch arrangement or the like could be provided which is configured to prevent the locking means 20 from disengaging inadvertently, such as for example a pin which may be passed through an aperture in one of the collars 58 and through a corresponding aperture in the base tube 4 to prevent rotation of the foot pedal 55.

In the present specification "comprises" means "includes or consist of" and "comprising" means "including or consisting of".

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS: 1. An access platform, the access platform comprising: a support

having a first part and a second part, said second part being substantially horizontally moveable relative to the first part; a pivotable frame pivotally mounted to the first part and moveable between a substantially horizontal storage position and at least one in-use position which lO is raised with respect to said storage position, a connection element being provided connecting said frame to the second part such that pivotal movement of the pivotable frame causes horizontal movement of the second part relative to the first part; an access platform unit being provided and being configured to engage the l 5 frame such that when the frame is in the or each in-use position the platform unit adopts an elevated position relative to said support.
2. An access platform according to claim l provided with a locking means configured to releasably lock the frame in the or each in-use position.
3. An access platform according to any preceding claim, wherein said first part telescopically engages said second part.
4. An access platform according to claim 3 as dependent on claim 2, wherein said locking means is configured to releasably lock said telescopically engaged first and second parts relative to one another.
5. An access platform according to claim 4, wherein said locking means comprises one or more locking apertures or recesses provided in one of said first and second parts, and a locking pin provided on the other of said parts, the locking pin being releasably engageable in the or each said aperture or recess.
6. An access platform according to claim 5, wherein said locking means comprises a plurality of said locking apertures or recesses, each said locking apertures or recess corresponding to discrete and respective said in-use positions.
7. An access platform according to claims 5 or 6, wherein the locking pin is biased towards engagement with the or each said locking aperture or recess.
8. An access platform according to claim 7, wherein said locking means further comprises a release element operable to move the locking pin against said bias.
9. An access platform according to claim 8, wherein said release element takes the form of a foot pedal.
10. An access platform according to any preceding claim, having a further frame pivotally mounted to the first part.
1 1. An access platform according to claim 10, wherein the platform unit is pivotally connected to both of said frames.
12. An access platform according to claim 11, wherein said frames are configured such that said platform unit remains substantially horizontal as said pivotable frame is moved between said storage position and the or each said in- use position.
13. An access platform according to any preceding claim, wherein the or each frame comprises a pair of substantially parallel stiles.
14. An access platform according to claim 13, wherein the or at least one of said frames is provided with at least one cross-member extending between the stiles.
15. An access platform according to claim 14, wherein the or at least one of said frames is a ladder frame comprising a plurality of said crossmembers in the form of rungs.
16. An access platform according to any preceding claim, wherein the connection element comprises a strut pivotally connected at one end to the pivotable frame and pivotally connected at the other end to the second part.
17. An access platform according to any one of claims 1 to 16, wherein said connection element comprises a pair of substantially parallel struts interconnected by at least one cross-member.
18. An access platform according to claim 16 or 17 as dependent on claim 1 4 or claim 15, wherein the or each strut is connected to one of the cross members of the or each respective frame.
19. An access platform according to any preceding claim, wherein the first part and the second part are each provided with at least one support formation configured to engage with the ground to support the access platform.
20. An access platform according to claim 19, wherein the or each support formation provided on at least one of said first and second parts, is mounted on a moveable outrigger configured for movement along an axis substantially perpendicular to the axis of said horizontal movement of the second part relative to the first part.
21. An access platform according to claim 19 or 20, wherein at least one said support formation comprises a castor.
22. An access platform according to any preceding claim, wherein the platform unit is provided with a collapsible structure comprising a guard rail configured to extend at least partially around a person standing on the platform unit, said collapsible structure allowing movement of the guard rail between a storage position substantially adjacent the platform unit and an operational position raised above the platform unit.
23. An access platform according to Claim 22, wherein when the guard rail is in said operational position it remains at the same raised height above the platform unit for any elevated position of the platform unit relative to said support.
24. An access platform according to claim 22 or 23, wherein the collapsible structure is configured such that said guard rail remains substantially horizontal as it is moved between its storage position and its operational position.
25. An access platform substantially as hereinbefore described with reference to and as shown in the Figures 1 to 6 of the accompanying drawings.
26. Any novel feature or combination of features disclosed herein.