GB2281897A

GB2281897A - Stackable wheeled platform.

Info

Publication number: GB2281897A
Application number: GB9319228A
Authority: GB
Inventors: Kevin Richard Bridges
Original assignee: Lin Pac Mouldings Ltd
Current assignee: Linpac Mouldings Ltd
Priority date: 1993-09-16
Filing date: 1993-09-16
Publication date: 1995-03-22
Anticipated expiration: 2013-09-16
Also published as: GB9319228D0; GB2281897B

Abstract

A wheeled platform assembly 10 had a rectangular platform 12 with a deck 14, fixed wheels (18, Fig. 1) and castored wheels (22). The deck 14 has alignment means 44, lying directly above each of the wheels 18, 22, and comprising two perpendicularly intersecting channels 46, 48 each extending diametrically across a circular recess and having downwardly directed deflecting surfaces 51 located between the intersected channels 46, 48. The channels 46, 48 have side walls (54, Fig. 3/4) and an upwardly extending projection 62 at the intersection of the two channels. When two similar assemblies are stacked in vertical alignment, the wheels (18, 22) of the upper assembly 10 engage the alignment means 44 of the lower assembly 10 and are deflected by the deflecting surfaces (51) into one or other of the channel means 46, 48, where they are restrained from horizontal displacement relative to the lower assembly by the channel side walls (54), a perimeter 58 of the recess and the projection 62. The platform is preferably a plastics moulding and has a handle 40 recessed into a triangular recess 42. <IMAGE>

Description

A Platform Assembly The present invention relates to platform assemblies and is primarily concerned with wheeled platform assemblies having load carrying decks with castor wheels which are to be stacked vertically when not in use.

Typically, wheeled platform assemblies are difficult to stack vertically since slight movement can cause the wheels of the upper assembly to roll about the deck of the lower assembly creating an unstable vertical stack, therefore recesses have been formed in the upper deck of such platforms into which the wheels of the overlying platform may to be placed to prevent them from moving relative to the lower deck structure.

It is an object of the present invention to provide a wheeled platform assembly which has an improved means for vertically stacking two or more such assemblies to form a stable stack.

According to the present invention there is provided a wheeled platform assembly comprising a substantially horizontal, rectangular platform having a deck and ground engaging castored wheels for moving the platform, said platform being adapted to receive on its deck a similar platform assembly and having alignment means for aligning and restraining the wheels of the upper platform assembly in a preferred orientation and position relative to the deck of the lower assembly, which alignment means comprises deflecting means positioned relative to channel means so that the castored wheels of the upper platform assembly may engage, and be deflected by, the deflecting means so as to be received and restrained in the channel means.

The alignment means will preferably comprise a recess in the deck and this recess, which will usually be circular, is for accommodating the deflecting means and channel means so that these means do not project proud of the horizontal surface of the deck.

The channel means may comprise two intersecting channels, each channel having parallel upstanding side walls and horizontal bases, where the upstanding side walls are for restraining relative horizontal movement between the channel and a wheel disposed therein, while the deflecting means may comprise an array of sloped surfaces disposed relative to and downwardly directed towards the channels so that engagement between these sloped surfaces and a castored wheel will cause the castored wheel to be deflected into one or other of the channels.

In its preferred form, in which the recess is circular, the two channels extend diametrically across the extent of the recess at right angles to one another, dividing the recess into four quarters, and may comprise an upwardly extending projection at the intersection of the two channels, creating four equal channel arms.

The deflecting means will preferably comprise four similar ridges, one each located in each quarter of the recess formed by the channels, so as to deflect the wheels of the upper platform assembly towards one of the channels disposed between adjacent ridges. Each ridge will usually be convex and extend radially outwards from the centre of the circular recess and increasing in height above the channel bases away from the centre of the recess to lie flush with the deck at the perimeter of the recess, and have sloped surfaces extending downwardly from the ridge towards the adjacent channels.

These sloped surfaces will preferably have concave surfaces so as to cause the castor of the castored wheel to rotate about a vertically extending axis so as to align the wheel with one or other of the channel arms into which the wheel will be deflected.

The platform assembly may comprise four alignment means disposed towards each of the four corners of the rectangular deck and having a wheel associated with each alignment means, of which at least two are castored wheels.

Furthermore, the deck may comprise a triangular recess with a handle formed across it, coplanar with the deck, and the platform will preferably made substantially as a plastics moulding.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings in which FIGURE 1 is a side elevation of a wheeled platform assembly; FIGURE 2 is a plan view of the platform assembly of Figure 1; FIGURE 3 is a plan view of a wheel alignment means; FIGURE 4 is a section of the alignment means along the line IV-IV of Figure 3; and FIGURE 5 is a part section of the alignment means section along the line V-V of Figure 3.

The mobile platform assembly 10 comprises a rectangular, substantially horizontal, platform 12 having a deck 14 and a base 16. This platform comprises a single plastics moulding.

The base 16 carries four wheels, two fixed wheels 18, fixed so as to rotate parallel to a longitudinally extending edge 20 of the platform 12, and two castored wheels 22. The four wheels 18, 22 are located one towards each of the four corners of the base 16, the two fixed wheels 18 disposed towards one laterally extending edge 24 of the platform 12 while the two castored wheels 22 are disposed towards the longitudinally opposed laterally extending edge 26 of the platform 12.

The castored wheel assemblies 22 may be considered to be of a standard structure, having a plate 25 with downwardly extending castor arms 28 rotatable about a vertically extending axis 30, and having a substantially cylindrical wheel 23 rotatable about a horizontal axis supported by the castor arms 28. The wheel being slightly offset from the vertically extending axis 30.

The deck 14 carries an array of castellations 32 which serve for locating and restraining containers on the deck when in use, and it will be appreciated that the array of such castellations will vary greatly on the requirements of the platform assemblies. Two handles 40 are also located on the deck 14, one towards each of the longitudinally opposed edges 24, 26. These handles 40 are formed flush with the deck 14, lying across one apex of a recessed triangle 42 and having sufficient space between the handle 40 and the recessed triangular surface to allow a hand or hook to be placed beneath the handle 40. The handle 40 is moulded integral with the platform 12.

Located in the deck 14, one towards each of the four corners of the rectangular deck 14 are four similar alignment means 44, best seen in Figure 3. Each alignment means 44 may be considered as being formed in a circular recess such that no part of the alignment means extends proud of the deck surface 14 (thereby alleviating the formation of an uneven deck surface on which loads may be placed in use).

Each alignment means 44 comprises two intersecting channels 46, 48, with both channels extending diametrically across the recess and intersecting, at its centre, at right angles, to form a uniform cross which divides the recess into four equal quarters 50. Each quarter 50 accommodates deflecting surfaces 51. The two channels 46, 48 extend parallel with the longitudinally extending edges 20 and the laterally extending edges 24, 26 of the platform respectively. Both channels 46, 48 have flat, substantially horizontal bases 52, conveniently formed by the base of the circular recess in which they are located. The channels each have upstanding and substantially parallel side walls 54. These walls 54 upstand from their respective bases 52 only partway of the vertical extent (depth) of the recess.

Each of the quarters 50, formed by the channels 46, 48, has a ridge 56 as best seen in Figure 5, with deflecting surfaces 51 extending downwardly therefrom. Each of the ridges 56 extend partway along a diametrical line, from the intersection of the two channels 46, 48, to the perimeter 58 of the recess. Each ridge 56 increases in height above the bases 52 of the channels 46,48, as it increases in radial distance from the intersection of the channels, until, at the perimeter 58, each ridge 50 is flush with the deck 14 (as seen in Figure 5). Figure 5 also shows how the line of each ridge (56) increases in height and such line is not uniform but presents a convex curve. On either side of each ridge 56 are the deflecting surfaces 51 which slope downwardly from the line of the ridge 56 to top edges 60 of the channel side walls 54 (as seen in Figure 4).These sloped deflecting surfaces 51 present a concave profile as seen in Figure 4.

At the centre of the circular recess is a conical projection 62 upstanding from the bases 52 of the channels 46, 48. This projection 62 serves to effectively divide the intersected channels 46, 48, into four separate channel portions 70, each of which corresponds in width and length to the size of wheels used in the wheel assemblies 18, 22.

When two similar platform assemblies 10 are stacked in vertical alignment, the wheels 18, 22 of the upper assembly 10 are roughly located so as to overlie the alignment means 44 of the deck 14 of the lower assembly 10. The fixed wheels 18 engage the sloped deflecting surfaces 51 of the alignment means of the lower assembly 10 and are deflected, under the weight of the upper assembly 10, towards one of the channel arms 70 which is orientated parallel to the longitudinally extending edge 20 of the platform 12, and hence extends in the same direction as the fixed wheel 18. The deflection of these fixed wheels 18 results in the deflection of the upper platform assembly 10 as a whole if the two vertically stacked platforms are not in close vertical alignment.The projection 62 also serves to deflect the wheel 18, by causing the wheel to rotate about its horizontal axis, into one of the two longitudinally extending channel arms 70 if it engages the wheel during this deflection stage.

The two castored wheels 22 of the upper assembly also engage the sloped deflecting surfaces 51 of their associated alignment means 44 of the lower assembly 10 and are deflected under the weight of the upper assembly 10 towards one of the four channel portions 70, the concave profile of the surfaces 51 serve to cause rotation of the castored wheel 22 about its vertically extending axis 30 so as to orientate the wheel 22 until it is parallel with the channel portion 70 towards which it is deflected. The castored wheels 22 may be deflected to any one of the four channel arms 70 since they are not held in one direction like the fixed wheels 18, but are freely rotatable about the vertically extending axis 30.

The width of the channels 46, 48 is designed to correspond closely with the width of the wheels so that when the wheels 18, 22 of the upper assembly 10 are positioned in the channels 46, 48 (within one of the four channel portions 70) of the lower assembly 10 they are restrained from displacement in one direction transversely with respect to those channels 46, 48 by the channel side walls 54, while the projection 62 and the perimeter 58 of the recess restrain the wheels from longitudinal displacement (by rolling) relative to the channels 46, 48. Thus the vertically stacked assemblies 10 are securely restrained from relative horizontal displacement when in vertical alignment.

The stacked assemblies 10 may be simply separated by lifting the upper assembly, by handles 40, so that the wheels 18, 22 of the upper assembly are lifted clear of the alignment means 44 of the lower assembly.

It will be appreciated that more than two assemblies 10 may be stacked vertically with the wheels of the overlying assembly engaging the alignment means of the assembly directly below.

It will be further appreciated that several variations to the preferred embodiment of the present invention as herein described and illustrated are possible. For example, the fixed wheels 18 may be replaced with castored wheels so that all four wheels are castored. In addition, a different array of wheels may be used, but each wheel having associated with it, on the overlying deck, an alignment means similar to that previously described. Furthermore, the bases 52 of the channel portions 70 may be recessed so as to accommodate the curve of the wheels received therein.

Other examples of the present invention could have the alignment means proud of the deck structure and/or such alignment means having more than two channels. Alternatively the alignment means could be accommodated in recesses which are not circular but, for example, could be substantially square.

Claims

1. A wheeled platform assembly comprising a substantially horizontal, rectangular platform having a deck and ground engaging castored wheels for moving the platform, said platform being adapted to receive on its deck a similar platform assembly and having alignment means for aligning and restraining the wheels of the upper platform assembly in a preferred orientation and position relative to the deck of the lower assembly, which alignment means comprises deflecting means positioned relative to channel means so that the castored wheels of the upper platform assembly may engage, and be deflected by, the deflecting means so as to be received and restrained in the channel means.

2. An assembly as claimed in claim 1 in which the alignment means comprises a recess in the deck, which recess accommodating the deflecting means and channel means so that these means do not project proud of the horizontal surface of the deck.

3. An assembly as claimed in claim 2 in which the recess is circular.

4. An assembly as claimed in any one of the preceding claims in which the channel means comprise two intersecting channels, each channel having parallel upstanding side walls and horizontal bases, wherein the upstanding side walls restrain relative horizontal movement between the channel and a wheel disposed therein.

5. An assembly as claimed in claim 4 in which the deflecting means comprises an array of sloped surfaces disposed relative to and downwardly directed towards the channels so that engagement between the sloped surfaces and a castored wheel will cause the castored wheel to be deflected into one or other of the channels.

6. An assembly as claimed in either claim 4 or claim 5 when appendant to claim 3 in which the two channels extend diametrically across the extent of the recess at right angles to one another, dividing the recess into four quarters.

7. An assembly as claimed in claim 6 which comprises an upwardly extending projection at the intersection of the two channels, creating four equal channel arms.

8. An assembly as claimed in either claim 6 or claim 7 in which each the deflecting means comprises four similar ridges, one each located in each quarter of the recess formed by the channels, so as to deflect the wheels of the upper platform assembly towards one of the channels disposed between adjacent ridges.

9. An assembly as claimed in claim 8 in which each ridge is convex and extends radially outwards from the centre of the circular recess and increasing in height above the channel bases away from the centre of the recess to lie flush with the deck at the perimeter of the recess, and having sloped surfaces extending downwardly from the ridge towards the adjacent channels.

10. An assembly as claimed in either claim 9 in which the sloped surfaces have concave surfaces so as to cause the castor of the castored wheel to rotate about a vertically extending axis so as to align the wheel with one or other of the channel arms into which the wheel will be deflected.

11. A platform assembly substantially as herein described with reference to the accompanying illustrative drawings.

11. An assembly as claimed in any one of the previous claims comprising four alignment means disposed towards each of the four corners of the rectangular deck and having a wheel associated with each alignment means, of which at least two are castored wheels.

12. An assembly as claimed in any one of the previous claims in which the deck comprises a triangular recess with a handle formed across it, coplanar with the deck.

13. An assembly as described in any one of the preceding claims in which the platform is made substantially as a plastics moulding.