GB2163206A

GB2163206A - A foldable platform

Info

Publication number: GB2163206A
Application number: GB08519069A
Authority: GB
Inventors: Harold John Baker; Alfred Charlton; Robert Harry Paine; Albert Francis Ball; John William Garrett; Donald Smammuel Kemp
Original assignee: AH ENGINEERING Ltd
Current assignee: AH ENGINEERING Ltd
Priority date: 1984-07-27
Filing date: 1985-07-29
Publication date: 1986-02-19
Also published as: GB8519069D0

Abstract

A foldable platform comprising a ground engageable frame 1, a platform member 3, mounted on said frame for movement from a folded position to an operative position and releasable retention means 14. The retention means is operable to prevent subsequent movement of the platform means from the operative position towards the folded position. The platform member folds within the frame for easy stowage. <IMAGE>

Description

SPECIFICATION A foldable platform The invention relates to a foldable platform and is particularly but not exciusively concerned with a platform which can used to assist persons in stepping on to and alighting from the steps of a bus or coach.

According to the invention there is provided a foldable platform comprising a ground engageable frame, a platform member mounted onsaid frame for movement from a folded position to an operative position and releasable retention means which is operable to prevent subsequent movement of the platform means fron the operative position towards the folded position.

Preferably the retention means is carried by the platform.

The retention means is preferably releasable by means of a foot engageable release element whereby a load applied by the foot to the element will enable the platform to be moved into the folded position. We prefer the element to be so placed on the platform that the load applied to the element by the foot will cause the platform member to move towards its folded position as soon as the retention means is released. Such an arrangement is useful in that it avoids the need to fold the platform member by hand, the releasing and folding operation being carried out by a single movement of the foot.

The platform is preferably pivotally mounted on the frame. The pivotal mounting for the platform member is preferably intermediate ends of the platform and the foot engageable release element may be positioned on a portion of the platform member between one of said ends and the pivotal mounting. In that way, load applied by the foot to the element can cause the said portion of the platform to move downwardly about the pivot thereby causing the remaining portion of the platform to swing upwardly into the folded position.

The retention means preferably includes a locking member which cooperates with a link which occupies a locking position where the platform member occupies its operative position. The link may be connected to said frame. The link is preferably arranged so that a portion thereof follows a path defined by a guide on the platform member as the latter is moved towards its operative position and the locking member preferably moves into the path as the platform member reaches the operative position to prevent movement of the link portion back along the path until the foot engageable release element has been operated thereby locking the platform member in its operative position. The link is preferably pivotally connected to the frame.The guide may comprise a slot preferably formed in a flange beneath the platform and the link may include a pin which projects through the slot to cooperate with the locking member. The locking member may have a surface which engages the link in wedge-like manner and/or may be formed with a pin-receiving recess.

Preferably the locking member is resiliently biased into a locking position. The resilient bias may be provided by a spring, e.g. a coil spring.

The foot engageable release element may comprise a plunger which is connected (e.g.

pivotally), to said locking member so that a load applied by the foot to the plunger will move the locking member clear of the aforesaid path. The aforesaid spring may extend between the platform member and a head of the plunger.

The platform member preferably carries one or more foldable legs spaced from the ground engageable frame.

Means may extend between the frame and the leg or legs so that when the platform member moves into the operative position, the leg or legs swing relative to the platform from a stowed position to a ground engaging position. Said means may include an arm which links the legs to the frame.

The frame is preferably shaped so as to receive the platform member within its periphery when the platform member is in its fully folded postion. Where the platform member carries one or more ground engageable legs, the leg or legs or at least a major part thereof lie, along with the platform, substantially within the periphery of the frame in the folded position. The frame is preferably contained substantially in one plane and in the folded position the platform member preferably lies substantially in the plane of the frame.

The frame may carry an auxiliary leg which can be moved from a stowed position on the frame to a ground engaging position to stabilise the platform.

The platform may be held in its folded position by retainer means e.g. a clip. The retainer means may be carried by the platform member.

The frame may be generally of inverted Ushape and the lower ends of the limbs thereof may form the legs.

Foldable platforms in accordance with 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 one embodiment of platform in accordance with the invention partly broken away; Figure 2 is an elevation of the platform on arrow II in Fig. 1; Figure 3 is a cross section of part of the platform on the line X-X in Fig. 2; Figure 4 is an elevation showing the platform in a partially folded condition; Figure 5 is an elevation showing the platform; Figures 6 and 6a are views of part of the platform showing cooperative parts of a locking member and link in locked and unlocked conditions respectively; Figure 7 is an elevation of an alternative type of platform in accordance with the invention; Figure 8 is an end view of the platform of Fig. 6 looking in the direction of arrow Z in Fig. 7;; Figure 9 is an elevation showing the platform of Fig. 6 folded Figure 10 and 10 are similar to Figs. 5 and 5a showing the locking member and link of the Fig. 6 platform and; Figure ii is a view of part of the Fig. 7 platform showing a spring clip for retaining the platform in the Fig. 9 condition.

The platform comprises a main frame 1 of generally inverted U-shape having spaced apart feet 2. A platform member 3 is pivotally connected to the frame 1 by a cross bar 4 which extends through the frame and through peripheral side flanges 4a of the platform member 3. The platform pivotally supports two legs 5. The legs 5 are connected through a cross bar 6 and an arm 7 to a further cross bar 8 on the main frame 1. The cross bar 8 pivotally carries one end of each of two spaced links 9 the opposite ends of which includes an interconnecting transverse pin 10.

The pin 10 runs in two aligned guide slots 1 2 formed in respective parallel flanges 1 3 of the channel member 1 3a suitably fastened to the underside of the platform member 3.

The pin 10 cooperates with the right hand end of an elongate locking member 14 which is pivotally mounted adjacent its left hand end on the cross bar 4. The left hand end of the locking member 14 is pivotally secured between the links of an inverted U-shaped member 1 5 which is connected to the lower end of a plunger 16. The plunger has a shank 17 which extends with working clearance through an aperture in the platform member 3, the shank terminating at a heads 1 8. A helical compression spring 1 9 is disposed around the shank 1 7 between the head 1 8 and the upper surface of the platform 3. The spring 1 9 normally biases the plunger upwardly thereby biasing the right hand end of the locking member downwardly.As can been seen from Figs. 5, 5a, the locking member 14 is urged against the pin 10 where the platform is nonhorizontal but the right hand end of the locking member 14 drops behind the pin 10 as the platform reaches its horizontal operative position as shown in Figs. 2, 5. As shown in Figs. 5 and 5a, the right hand end of the locking member 14 has a surface 20 which is inclined to the axis of member 14 by an angle O (typically 75 to 80)so that the surface effects a wedge-like action on the pin to urge it firmly against the right hand ends of the guide slots 1 2. The locking member may include an overlying finger 22 which will prevent the right hand end slipping past the pin 10 in the event of the surface 20 becoming excessively worn.

The location of the arm 7 on the cross bars 6, 8 and the spacing of links 9 on cross bar 6 is effected by spacer tubes 23 of aluminum or plastics carried by the cross bars.

The frame 1 may pivotally support an auxiliary leg 30 which pivots downwardly from the broken line position to engage the ground.

The leg 30 helps to inhibit any tipping of the platform in direction Y when in use. The leg 30 is engageable with a clip 31 on the platform member 3 when the latter occupies the Fig. 4 position to hold the platform member in its folded position.

In the use the platform is initially in a folded position as shown in Fig. 4 with the platform member 3 lying within the frame 1, the platform member, legs 5 and frame 1 lying substantially within the same plane. The arms 7 and links 9 are cranked at 24, 25 respectively so that in the folded position they clear cross bar 4. To unfold the platform, the leg 30 is released from clip 31 and the platform member 3 is pivoted downwardly into the horizontal position in which it is locked by member 14. The leg 30 is then moved into the Fig. 1 full line position to increase stability. The platform can then be used to assist stepping into and alighting from a bus or coach, the side of the platform indicated at S being placed adjacent the coach. Users grasp the upper end of frame 1 to steady themselves as they step on to the platform member 3.

To fold the platform a load is applied by foot to the plunger 1 6 whilst hilding the frame steady. The load compresses spring 1 9 and moves surface 20 of locking member 14 clear of the pin 1 0. Continued application of load pivots the platform member about cross bar 4 so that the section of the platform member 3 to the right of the cross bar 4 pivots upwards as in Fig. 3 and finally moves into the Fig. 4 position. The leg 30 is then located in the clip 31.

It will be noted from Fig. 2 that the legs 5 project slightly beyond the right hand end of the platform member 3. This is advantageous in that a downward load applied to that end of the platform will not cause the platform to tip.

The frame 1 preferably incorporates a hand grip 40 to enable it to be grasped easily and to enable the frame to be carried easily in the folded position.

Reference is now made to Figs. 7 to 11 in which parts corresponding to parts in Figs. 1 to 6 carry the same reference numerals.

Main frame 1 has one of its vertical members 50 bent outwardly as in Fig. 8 to provide first and second hand grips 52, 53. As in Fig.

1 the platform member 3 is pivotally con nected to the frame 1 by a cross bar 4 which extends through the frame and through the peripheral side flanges 4a of the platform member 3.

A cross bar 8 pivotally carries one end of each of the two spaced links 9 which are interconnected by pin 10 as in Fig. 1 platform, the pin being slidable in the slots 1 2.

Unlike Fig. 1 the links 9 are interconnected by a rod 55 which pivotally supports one end of an arm 56 broadly equivalent to arm 7 in Fig. 1. The other end of arm 56 pivotally mounted on the cross bar 6 extending between the two legs 5 pivoted (e.g. on a further cross bar 58)on the platform member 3.

Unlike the Fig. 1 platform, the legs 5 are straight to simplify manufacture.

The pin 10 cooperates with the right hand end of the elongate locking member 14 which is pivotally mounted adjacent its left hand end on the cross bar 4, The left hand end of the locking member 14 is screwed directly to the plunger 1 6 in this case the shank 1 7 of which extends with working clearance through an aperture in the platform member 3.

As in the previous embodiment a helical compression spring 1 9 is disposed around the shank 1 7 between the head 1 8 of the plunger and the upper surface of the platform 3. The locking member 14 is urged against the pin 10 where the platform is non-horizontal but the right hand end of the locking member 14 is formed with an oblique recess 57 which receives the pin 10 as the platform reaches its horizontal operative position as shown in Figs.

7, 9.

The platform is folded in a similar manner to that of Figs. 1 to 6 by applying a load by the foot to the plunger 1 6. The application of the load causes the recess 57 to disengage the pin so that the platform member an swing upwardly into the Fig. 9 position.

The legs 5 pivot into a near fully folded position (chain dotted lines in Fig. 9) on raising the platform member 3 and are pushed manually into the Fig. 9 position so that the cross bar 6 lies overcentre in relation to a notional line joining the cross bar 58 and the pin 55. In the Fig. 9 position a spring clip 59 mounted on the platform 3 snap-fits on to the frame 1 to hold the platform securely in a folded condition. However, should the clip accidentally disengage the frame, the overcentre arrangement of cross bar 6 prevents the platform falling into a horizontal position.

Therefore, to unfold the platform it is necessary both to release the clip 59 and to pivot the legs 5 into the claim dotted position before the platform can be lowered.

In the embodiment of Figs. 7 to 11 no auxiliary leg is provided as the forming of frame 1 to position the hand grips 52, 53 offset from a vertical plane containing the longitudinal centre line of the platform tends to cause a typical L load applied to the handgrips by a user to be directed towards a point inside the lower ends of the platform legs.

As shown in Fig. 7, the member 1 3a extends substantially the full length of the platform member which increases the stiffness of the platform member. The flanges 1 3 are cutaway at 60 to receive the cross bar 6 in the folded position.

Claims

1. A foldable platform comprising a ground engageable frame, a platform member mounted on said frame for movement from a folded position to an operative position and releasable retention means which is operable to prevent subsequent movement of the platform means from the operative position towards the folded position.

2. A foldable platform according to Claim 1 in which the retention means is carried by the platform.

3. A foldable platform according to Claim 1 or 2 in which the retention means includes a foot engageable release element whereby a load applied by the foot to the element will enable the platform member to be moved into the folded position.

4. A foldable platform according to Claim 3 in which the element is arranged whereby the load applied to the element by the foot will cause the platform member to move towards its folded position as soon as the retention means is released.

5. A foldable platform according to any preceding claim in which the platform member is pivotally mounted on the frame.

6. A foldable platform according to Claim 5 in which the pivotal mounting is intermediate ends of the platform member.

7. A foldable platform according to Claim 6 and in the case where said foot engageable release element is provided, in which the foot engageable release element is positioned on a portion of the platform member between one of said ends and the pivotal mounting.

8. A foldable platform according to any preceding claim in which the retention means includes a locking member which co-operates with a link which occupies a locking position where the platform member occupies its operative position.

9. A foldable platform according to Claim 8 in which the link is connected to said frame.

1 0. A foldable platform according to Claim 8 or 9 in which the link is arranged so that a portion thereof follows a path defined by a guide on the platform member as the latter is moved between its operative and folded position.

11. A foldable platform according to Claim 10 in which the guide comprises a slot

1 2. A foldable platform according to Claim 11 in which the slot is formed in a flange beneath the platform.

1 3. A foldable platform according to Claim 10, 11 or 1 2 in which the locking member is arranged to move into the path as the platform member reaches the operative position to prevent movement of the link portion back along the path until the retention means has been released thereby locking the platform member in its operative position.

14. A foldable platform according to any of Claims 9 to 1 3 where the link is connected to said frame, in which the link is pivotally connected to said frame.

15. A foldable platform according to any of Claims 11 to 14 and in the case where the guide comprises a slot, in which the link includes a pin which projects through the slot to co-operate with the locking member.

1 6. A foldable platform according to Claim 1 5 in which the locking member is formed with a recesses which receives the pin.

1 7. A foldable platform according to any preceding claim and in the case where the retention means includes said locking member, in which the locking member has a surface which engages the link in a wedgelike manner.

1 8. A foldable platform according to any preceding claim in which the retention means is resilientiy biased into a retaining position.

1 9. A foldable platform according to Claim 1 8 in which the resilient bias is provided by a coil spring.

20. A foldable platform according to any preceding claim and in the case where a foot engageable release element and a locking member are provided, in which the release element is connected to the locking member so that a load applied by the foot to the element will operate the locking member.

21. A foldable platform according to Claim 20 in which the element is pivotally connected to the locking member.

22. A foldable platform according to-any preceding claim and in the case where a foot engageable release element is provided, in which the element is a plunger

23. A foldable platform according to any preceding claim in which the platform member carries one or more foldable legs spaced from the ground engageable frame.

24. A foldable platform according to Claim 23 in which means extends between the frame and the leg or legs so that when the platform member moves into the operative position, the leg or legs swing relative to the platform from a stowed position to a ground engaging position.

25. A foldable platform according to Claim 24 in which said means includes an arm which links the leg or legs to the frame.

26. A foldable platform according to Claim 25 in which the arm is pivotally connected to the leg or legs.

27. A foldable platform according to any preceding claim in which the frame is shaped so as to receive the platform member within its periphery when the platform member is in its folded position.

28. A foldable platform according to Claim 27 and in the case where the platform member carries one or more legs, in which the leg or legs or at least a major part thereof lie, along with the platform, substantially within the periphery of the frame in the folded position.

29. A foldable platform according to Claim 27 or 28 in which the frame is contained substantially in one plane and in the folded position the platform member lies substantially in the plane of the frame.

30. A foldable platform according to any preceding claim in which the frame carries an auxiliary leg which can be moved from a stowed position on the frame to a ground engaging position to stabilise the platform.

31. A foldable platform according to any preceding claim in which the platform is held in its folded position by clip means.

32. A foldable platform according to Claim 31 in which the clip means is carried by the platform member.

33. A foldable platform according to any preceding claim in which the frame is generally of inverted U-shape.

34. A foldable platform according to Claim 33 in which the lower ends of the limbs of the inverted U-shape frame form two legs.

35. A foldable platform constructed and arranged substantially as described herein with reference to Figs. 1 to 6 or Figs. 7 to 11 of the accompanying drawings.