EP0444386A1

EP0444386A1 - A mobile platform for disabled persons affording access to and from vehicles, in particular railway carriages

Info

Publication number: EP0444386A1
Application number: EP90830257A
Authority: EP
Inventors: Claudio Morara; Claudio Menzani
Original assignee: CASARALTA SpA
Current assignee: CASARALTA SpA
Priority date: 1990-02-27
Filing date: 1990-06-08
Publication date: 1991-09-04
Also published as: IT9003357A0; IT1238252B; IT9003357A1

Abstract

The platform is designed around a central frame (4) supported slidably between two fixed beams (5a, 5b) anchored to the chassis (1) of a railway carriage and traversed by a suitable drive (6) across the carriage axis so as to extend sideways from either one of the two doorways (2a, 2b) afforded by the vestibule; the frame (4) incorporates two decks (7) on which to support a wheelchair (9), located on opposite sides in a common plane and independently driven by belts (10) in such a way as to enable their vertical movement, when the central frame (4) is extended, between a position of horizontal alignment with the frame and a lowered position at the level of the trackside surface (3) beneath.

Description

The present invention relates to a mobile platform by means of which disabled persons may board and alight from vehicles, and in particular railway carriages.
For any disabled person confined to a wheelchair, the problem of boarding and alighting from road vehicles or railway carriages is one still lacking a definitive solution, and especially in the case of railway carriages.
Whereas for motor vehicles, a variety of equipment or apparatus has been designed and built (featuring pneumatic or mechanical devices in many instances), by means of which it has become possible to some extent to move a disabled person in a wheelchair swiftly and easily into and out of a motor vehicle, there has never been any such structure, nor even an accessory, designed for use specifically in conjunction with railway carriages and capable of facilitating access for a disabled person wishing to make use of rail transport.
The disabled person confined to a wheel chair is in fact denied such access by way of the conventional entry points to rail carriages, with their steeply angled steps and narrow doorways, and of necessity, accommodation is provided currently in carriages affording greater manoeuvring space (e.g. the mail car) or at all events in carriages not specifically designated for passenger use; this in no sense constitutes a solution however, but is simply a makeshift and especially uncomfortable arrangement that permits of catering for disabled persons on an occasional basis, given the lack of any suitable structure in conventional rolling stock.
The need is thus discerned by the applicant for a mobile platform that can be suitably operated by railway staff and will allow a disabled person to enter, occupy and subsequently leave the vestibule of a railway carriage, without leaving his or her wheelchair, and at the same time, without modifying the basic constructional specifications of current rolling stock.
Accordingly, the object of the present invention is to embody a platform that will provide for the ascent and descent of disabled persons into and from railway carriages, exhibiting a structure such as requires no alteration to the architecture of the carriage, and featuring simple, safe operation. The stated object is achieved in a mobile platform as characterized in the appended claims, which consists essentially in a central frame slidably supported by two beams fixed permanently to the chassis of a railway carriage. The central frame is set in motion by relative drive means, and capable of movement transversely to the longitudinal axis of the chassis in such a way as to extend on either side through one of the two doorways afforded by the carriage. The central frame is also provided with a pair of decks to support a wheelchair, which lie on opposite sides in a common plane and are power driven independently by belt means in such a way as to manoeuvre vertically, when the central frame is extended from the carriage, between a position of alignment with the frame and a lowered position substantially level with the trackside pedestrian surface.
Among the advantages of the present invention is that it sets forth a compact unit comprising all such elements as are necessary to enable a disabled person's boarding and/or alighting from a railway carriage, which can be fitted in its entirety to the vestibule of the carriage without any need for prior modification, and operated thus safely and faultlessly.
The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which:

fig 1 is a schematic illustration of the platform according to the present invention, fitted to a railway carriage, viewed in plan from above and seen in two operating configurations;
fig 2 is a view of the platform of fig 1 taken through II-II, seen with certain parts cut away better to reveal others;
fig 3 is the section through III-III of fig 1, showing a part of one of the moving decks with which the platform is provided, seen with certain parts cut away better to reveal others;
fig 4 illustrates a part of the platform of fig 1, viewed in plan and with certain parts cut away;
figs 5, 5a and 5b are respective side elevations of the decks of the platform disclosed, showing three different operating configurations;
fig 6 illustrates a safety device with which each deck of the platform is provided, viewed in plan from above;
fig 7 is the side elevation of a railway carriage fitted with the platform of fig 1;
fig 8 shows part of the railway carriage of fig 7, viewed in perspective with the platform in a given operating position.

With reference to the drawings, the mobile platform according to the invention is intended for use in conjunction especially with a railway carriage (illustrated schematically in figs 1 and 7); the carriage consists essentially in a fixed chassis 1 affording a first floor level 1a that coincides with vestibule areas located one at each end. Each such end area of the carriage affords two doorways, denoted 2a and 2b in fig 1, positioned opposite one another, by way of which passengers can enter the carriage or alight onto a trackside area 3 lying at a height H lower than the first floor level 1a of the carriage.
In the example of fig 1, the railway carriage is of a type designed with two floor levels, the higher level being reached by way of a flight of steps GR of which the individual height is denoted G1; needless to say, however, the essential concept of the present invention is by no means limited to any one type of carriage.
According to the present invention, the platform comprises essentially two principal components, namely: a horizontally traversing central frame 4, and a pair of decks 7 capable of vertical movement independently of the central frame 4. More exactly, the central frame 4 (figs 1 and 2) is positioned at the first floor level 1a and serves in its turn to establish a second floor level 1b set at a height G greater than that of the first and creating a full step, preferably equal to the height G1 of the carriage steps GR.
The central frame 4 runs across the carriage and is carried slidably between a pair of fixed beams 5a and 5b (hollow sections, for example, of which one only 5a is visible in fig 2) rigidly associated with the first floor level 1a.
6 denotes drive means housed between the two floor levels 1a and lb, by which the central frame 4 can be traversed horizontally in either direction F (see figs 1 and 8) between a non-operative limit position (not illustrated), in which the frame 4 simply constitutes the second floor level 1b, and an operative position in which the frame projects a given distance externally of a relative doorway 2a or 2b.
In the particular example illustrated (see fig 2), drive means 6 for the central frame 4 comprise a first vertical shaft 12 driven by a first geared motor 45 positioned substantially to coincide with the transverse axis X of the frame 4, and a timing pulley 12p keyed to the shaft 12 and flanked by idle tension pulleys 13; a timing belt 14 is looped around the keyed pulley 12p, over the idle tension pulleys 13 and around two second timing pulleys 15 disposed symmetrically one on either side of the transverse axis X of the central frame 4. Each such second pulley 15 is keyed in turn to a respective second vertical shaft 16 the central part of which carries a keyed gear 17 meshing with a further gear denoted 17a, which in turn meshes with a horizontal rack 18 secured to the side of the central frame 4. The rack 18 is provided with travel limiting means denoted 50 in fig 1, which are designed to stop the frame 4 in either of the two aforementioned limit positions, and fitted to the sides of the frame 4 at points which coincide substantially with the transverse axis X of the frame when the frame is in the non-operative position, and at all events, in such a way at least as to ensure complete extension of either deck 7 before the traversing movement of the frame ceases. The travel limiting means 50 themselves are operated by contact with or striking against a corresponding transducer or cam mounted to the fixed beam 5a (operation of the limiter may be mechanical, optical or electric depending on whether the platform drive system is electric or pneumatic).
The decks 7 serve to accommodate the wheelchair 9 of a disabled person boarding or alighting, and are located one at each end of the frame 4, disposed symmetrically in relation to the transverse axis X. Each deck 7 constitutes an integral part of the frame, and incorporates means 8 by which to ensure stable positioning of the wheels 9a of the chair 9. Such means 8 consist in a pair of quadrangular recesses 19 (see fig 3) afforded by the internal area of each deck 7, each recess in turn affording a matching plate 19a that serves both as a cover and as a support for the relative wheel 9a.
The single plate 19a is capable of movement (in the direction of the arrow denoted F1 in fig 3) between a raised, at-rest position of alignment with the plane of the deck 7, in which the recess 19 is covered, and a lowered working position assumed when occupied by the wheel 9a of a chair, in which the plate 19a descends fully into and settles on the bottom 19f of the recess 19. Each plate 19a is provided with travel limiting means 20 associated with its underside and consisting in a pair of arms or lugs 20a, fixed at right angles to the plate itself and carrying a roller 35 at bottom that is rotatable about its own axis and designed to bring about the return of the plate 19a to the at-rest position when the deck 7 is in a lowered position (shortly to be illustrated), and also upon passage of the central frame 4 from the operative to the non-operative position. The latter repositioning manoeuvre occurs through contact of the roller 35 with a corresponding stop or distance rail 36 that is part angled and rigidly associated with the chassis 1 of the carriage. Also associated with the underside of each plate 19a are three U-shaped supporting arms 60 (see figs 3 and 4), disposed parallel one with another and anchored at their respective ends to the internal area of the plate and to the internal area of the deck 7 in the manner of an articulated parallelogram linkage, by which the plate 19a is kept in alignment with and parallel to the remainder of the deck 7 throughout the various stages of its movement. The supporting arms 60 naturally will be of depth and position so as not to interfere with the limit roller 35.
The two decks 7 are capable of movement not only independently of the central frame 4, as mentioned above, but also of one another; this facility is provided by belt drive means 10 housed within the central frame 4 and operating on both sides of each deck 7 in such a way as to enable movement in a vertical direction, with the frame 4 occupying the operative position needless to say, between two limit positions: elevated, in which the deck 7 occupies the same plane as the central frame 4, and lowered, with the deck 7 on a level substantially corresponding to that of the trackside 3. More in detail, the single deck 7 comprises two parallel side members 7a each lying adjacent to the central frame 4 and partially accommodating the belt drive means 10, which are capable of vertical movement between the elevated and lowered limit positions aforesaid. The area between the side members 7a is occupied by a table 7b that supports the wheels 9a of the chair 9 and is likewise capable of movement between two limit positions derived from the belt drive means 10, though only with the side members 7a in the lowered position: a raised non-operative position, whereby the table 7b is distanced from the trackside surface 3 at a height substantially equal to that of the side members 7a, and a lowered operative position in which the table 7b is set down effectively on the trackside surface in such a way that a wheelchair 9 can roll onto or off the platform. Further travel limiting means 53 located between the table 7b and the side members 7a permit of locking the belt drive means 10 once the deck has reached the lowered limit position.
In the example of the drawings (figs 4 and 5 in particular), movement of the deck 7 thus structured is produced by belt drive means 10 that comprise a pair of first pulleys 21 and 21a, mounted laterally between the end of the side member 7a innermost in relation to the central frame 4, and the fixed beams 5a and 5b, and keyed to a horizontal shaft 22 driven by a corresponding second motor 46. These first pulleys 21 and 21a are paired with respective belts 23 and 23a of which the former extends parallel to the side member 7a from the relative first pulley 21 to the projecting end of the side member, and the latter runs perpendicular from the corresponding first pulley 21a to the innermost end of the side member 7a; each belt 23 and 23a is anchored at one end to the relative first pulley 21 and 21a and at the remaining end to a respective second pulley 24 and 24a permanently associated with the deck 7, passing additionally around a set of intermediate third pulleys 25s, of which one denoted 25 is capable of movement internally of a relative vertical channel 25a in the side member 7a and permanently associated with the table 7b. The third pulleys 25s serve to keep the belts tensioned with the deck 7 occupying either of the elevated or lowered limit positions. 51 denotes travel limiting means fitted to the innermost edge of each table 7b (such means may also be of different type depending on the drive system adopted), which interact with a relative transducer or receiver 52 fitted to the central frame 4 and serve to lock the belts 23 and 23a, hence the deck 7, on arrival at the elevated limit position.
Whereas one side of one deck 7 only is detailed in the drawings, in the interests of simplicity, each deck 7 is in fact equipped with a relative motor 46 and a pair of belts 23-23a along each longitudinal flank, as fig 1 clearly illustrates; to occasion the movement of the matching pair of belts 23 and 23a located on the longitudinal side of the deck 7 opposite from the motor, the end of the horizontal drive shaft 22 adjacent to the table 7b is fitted with a gear 26 in mesh with a further gear 27, this in its turn integral with a transmission shaft 28 mounted rotatably to and passing transversely through the central frame 4 to connect at the far end, by way of a third gear (not illustrated, being identical to that denoted 27) with an identical assembly comprising gear 26, horizontal shaft 22 and first pulleys 21 and 21a, in such a way as to synchronize the movements of the four belts 23 and 23a in elevating and lowering the deck 7.
11 denotes vertical guide means associated with the two sides of each deck 7, which serve to keep the decks parallel with the trackside surface 3 when manoeuvring from one limit position to the other. In the example illustrated (see figs 5, 5a and 5b in particular) such guide means 11 consist in a pantograph 30 associated with each longitudinal flank of the single deck 7, housed internally of the corresponding side member 7a and anchored by its ends to the central frame 4 and the side member itself, respectively. Thus installed, each such pantograph 30 is capable of movement in the usual manner, the end anchored to the side member 7a being slidable in a relative slot 30a afforded by the side member itself, between two limit positions of minimum and maximum extension which coincide with the limit positions of the deck 7.
As illustrated in figs 3 and 5..., the outermost edge of each table 7b carries a hinged ramp 32, freely rotatable about a pivot denoted 32d and extending across the entire breadth of the table. The ramp 32 is also supported from beneath, at each end or thereabouts, by a jacking strut 33 freely connected at one end 33a to the crank arm 34a of an operating lever 34 disposed parallel with the strut and pivoted at mid-point to the side member 7a; this same operating lever 34 is also anchored rotatably at one end 34b to the aforementioned moving third pulley 25, which lies alongside the outermost end of the side member 7a. The jacking strut 33 is also made to slide in a substantially horizontal direction through a hole 33f fashioned in the fascia of the table 7b. Thus supported, the ramp 32 can be angled between a non-operative position, adopted in the elevated position of the table 7b, in which the face of the ramp is disposed at right angles to the table and the strut 33 distanced from the ramp, and an operative position coinciding with the lowered position of the table, in which the ramp is disposed at an angle denoted α in relation to the table (fig 5b) and the strut 33 motioned forward against its underside by rotation of the operating lever 34.
In order to protect the moving parts thus described in the course of the various movements effected by the decks 7, the front of each side member 7a is fitted with a boot 38 anchored by its ends to the central frame 4, and to the member itself (figs 4, 5... and 8); added protection is afforded laterally of the side member 7a by a first cloth denoted 39, which unwinds from a parallel first roller 39a accommodated internally of the central frame 4.
Thus, unfolding and unwinding together, the boot 38 and the cloths 39 ensure that the belt drive means 10 and the guide means 11 remain protected during passage of the deck 7 from the elevated position to the lowered position.
Similarly, a second cloth 40 associated with the innermost edge of the table 7b (see figs 3 and 4), anchored by one end to a corresponding second roller 40a mounted rotatably to the table itself, and to the central frame 4 at its remaining end, serves to cover the rear part of the table 7b during passage between the limit positions of the deck 7.
The platform will of course be provided with a number of safety devices. Each deck 7, for example, incorporates a mechanical device that will lock the pantograph 30 in the event of belt failure, and is caused to operate whenever the belts 23 and 23a may register insufficient tension; as discernible in fig 6, in fact, one of the moving third pulleys 25 (that denoted 25b), is mounted so as to oscillate in the manner of a jockey, tensioned into a lowered operative position by the action of the respective belt 23 and 23 against a spring (not illustrated), and connected to one respective end of a double lever 55 accommodated within each side member 7a.
The two sections of the double lever 55, which are capable of reciprocating horizontally, project from the respective ends of the relative member 7a and are interconnected by a rocker arm 56 pivotably mounted at centre to the side member 7a. The rocker arm 56 is located to coincide with the end of a locking rod 57 pivoted likewise at one end to the side member 7a, which affords a set of teeth 57a offered to a matching set of teeth 58 associated with the moving end of the relative pantograph 30.
Should either belt 23 or 23a happen to break during operation, the corresponding third pulley 25b will no longer be biased toward its lowered operative position, but rotate upwards (under the force of the spring). This movement causes the corresponding section of the lever 55 to shift forward, rotating the rocker arm 56 and causing a pin 56a carried by the arm to impinge on the end of the locking rod 57 and bring the two sets of teeth 57a and 58 into frontal engagement, thereby inhibiting further movement of the pantographs 30 (the locked position is shown by the bold line of fig 6). 59 denotes a sensor or optical device located alongside the locking rod 57, the purpose of which is to pilot the locking action of the belts 23 and 23a during normal operation.
Likewise with safety in view, the system by which the central frame is driven (rack and pinion) will be connected to manually operated release levers consisting, for example, in a flexible linkage 99 connecting with each of the doorways 2a and 2b (see fig 1). In the event of a power failure occurring, the linkage could be operated through a suitably located flap, for example, so as to release the clutch (permanently coupled) of the first motor 45 and allow the central frame to be pushed back to the inboard position by hand.
With a platform designed and constructed as per the foregoing description, a disabled person confined to a wheelchair can be afforded access to and from a railway carriage in the following manner. In the case, for example, of the disabled person alighting from the railway carriage, the railways attendant will be stationed alongside a set of push buttons 47 mounted to the exterior of the carriage and providing control over the various movements of the platform, whilst the wheelchair 9 is moved onto the deck 7 nearest the doorway at the trackside 3 (that denoted 2a in the example of figs 1 and 8) with its wheels 9a planted squarely on the recess plates 19a.
The attendant now operates the first motor 45 to traverse the central frame 4 through the doorway 2a to the point where it projects from the carriage at least far enough to bring the deck 7 fully out of the vestibule (as illustrated in fig 1). As the deck moves forward, the plates 19a will be lowered by the action of the rollers 35 which, no longer afforded support by the distance rails 36, allow each plate to drop under its own weight and settle on the bottom 19f of the relative recess 19.
With the central frame 4 extended to the position of figs 1 and 5, engagement of the relative travel limiting means 50 will automatically generate a signal to switch in the second motor 46 and start up the drive of the deck 7, which thereupon begins its descent toward the trackside surface 3 as the four belts 23-23a and the two pantographs 30 are set in motion (fig 5a). The moment the two side members 7a touch the trackside surface 3, the third pulleys 25 begin moving down the relative vertical channels 25a under their own weight, causing the table 7b (rigidly associated with the rollers 25, it will be remembered), to descend further until full contact is made with the trackside 3 (fig 5b); at this point, the relative limiting means 53 will operate to enable the full locking action of the belts 23 and 23a.
At the same time, the jacking rods 33 are rotated by the relative third pulleys 25b, and the ramp 32 swings through the angle α whereby it is brought into the operative position of fig 5b.
At the moment in which the table 7b is brought to the level of the trackside surface 3, the limit rollers 35 strike firm ground, causing the relative plates 19a to return to the raised position and freeing the wheels 9a of the chair 9, whereupon the chair can roll off onto the trackside surface 3 (fig 8).
Naturally enough, the boarding procedure whereby a wheelchair is elevated from the trackside 3 to the vestibule of the railway carriage involves the same sequence of steps as described above, implemented in reverse order.
A platform thus structured affords certain notable advantages: the assembly of central frame, decks and beams (including the relative drive and travel limiting means, needless to say), forms a single unit complete with means, denoted 41 in fig 1, for fastening to the first floor level 1a; such a unit can be fully integrated into the existing carriage floor (see figs 7 and 8 in particular), and its inclusion results in one part of the vestibule area being raised by an amount preferably equal to the height G1 of the adjacent passenger steps GR. What is more, the unit is especially robust, capable of withstanding the everyday traffic of passengers descending via the vestibule onto the trackside, and creates no visible obstacle that might obstruct their passage.
Clearly enough, with suitably modified dimensions, the platform structure disclosed might be fitted to other types of railway carriage not specifically mentioned in the foregoing specification, without by any means detracting from the substance of the invention as claimed below.

Claims

A mobile platform for disabled persons affording access to and from vehicles, in particular railway carriages consisting in a permanent chassis (1) with at least one first floor level (1a) enclosed by vestibule areas located one at each end of the carriage and affording two doorways (2a, 2b) each, disposed one opposite the other on either side, by which access is provided to and from the vestibule from and to a trackside pedestrian surface (3) lying at a height (H) lower than that of the first floor level (1a),
characterized
in that it comprises:
- a movable central frame (4) positioned at the first floor level (1a) and establishing a second floor level (1b) at a given height (G) above the first, extending transversely across the carriage and supported slidably on either flank between two fixed beams (5a) rigidly associated with the first floor level (1a);

- drive means (6) located between the two floor levels (1a, 1b), by which the central frame (4) is traversed horizontally back and forth between at least a non-operative inboard limit position, in which the frame (4) functions as the second floor level (1b), and an operative position in which the frame projects externally in part beyond one of the doorways (2a, 2b);

- a pair of decks (7) for the support of a wheel chair (9), incorporated one into each end of the central frame (4) and disposed symmetrically on either side of its transverse axis, and provided each with means (8) by which to position the wheels (9a) of the chair (9);

- belt drive means (10) housed internally of the central frame (4) and associated with each side of each deck (7), by which the single deck is invested independently with vertical movement when the frame is in the operative position, between at least an elevated limit position, in which the deck (7) is aligned with the central frame (4) in a common plane, and a lowered limit position in which the deck is disposed substantially at the height (H) of the trackside pedestrian surface (3);

- guide means (11) associated with each side of each deck (7), by which the single deck is maintained parallel with the trackside surface (3) while manoeuvring from one limit position to the other.
A platform as in claim 1, wherein each deck (7) incorporates two parallel side members (7a), each disposed adjacent to the central frame (4) and accommodating the belt drive means (10) and the guide means (11) in part, and capable of movement between the elevated and lowered limit positions, and a table (7b) located between the side members (7a), serving to support the wheels (9a) of the wheelchair (9) and capable of movement in its turn between two limit positions whenever the side members (7a) occupy the lowered limit position: a non-operative raised position, in which the table (7b) is substantially distanced from the trackside surface (3), and an operative lowered position in which the table substantially coincides with the trackside surface, thereby permitting a wheelchair to roll on or roll off the platform.
A platform as in claim 1, wherein the central frame (4) is traversed by drive means (6) that consist in a first vertical shaft (12) rotatable about its own axis, coinciding substantially with the transverse axis of the central frame (4) and driving a timing belt (14) looped around a pair of second timing pulleys (15) disposed symmetrically on either side of the same transverse axis, each keyed to and rotatable with a corresponding second shaft (16) disposed parallel to the first shaft and affording a keyed gear (17) in mesh with a relative second gear (17a) meshing in turn with a horizontally disposed rack (18) secured to the side of the central frame (4).
A platform as in claim 1, wherein means (8) by which to position the wheels (9a) of a chair (9) comprise:
- a pair of recesses (19) afforded by the internal area of each deck (7), each covered by a matching plate (19a) that affords support to a relative wheel (9a) and is capable of movement under the resulting weight between a raised at-rest position of horizontal alignment with the deck (7), in which the recess (19) is covered, and a lowered working position in which the plate (19a) comes to rest on the bottom (19f) of the recess (19) while occupied by the wheel (9a);

- travel limiting means (20) associated with the underside of each plate (19a), designed to enable the return of the plate (19a) to the raised at-rest position both when the deck (7) is in the lowered position and when the central frame (4) is returned from the operative position to the non-operative inboard position;

- a set of at least three U-shaped arms (60) associated with the underside of each plate (19a), each parallel with the other and anchored by their opposite ends to the internal area of the plate and to the internal area of the deck (7), respectively, in such a way as to articulate in the manner of a parallelogram linkage and permit of aligning the plate (19a) with the deck (7).
A platform as in claim 4, wherein travel limiting means (20) consist in a pair of lugs (20a) fixed to the underside of the plate (19a) and carrying a roller (35) at their projecting ends that is rotatable about its own axis and designed to bring about the return of the plate (19a) to the at-rest position both when the deck (7) is in the lowered position and on passage of the central frame (4) from the operative to the non-operative inboard position, through contact of the roller (35) with a corresponding distance rail (36) rigidly associated with the chassis (1) of the carriage.
A platform as in claim 1, wherein the belt drive means (10) of each deck (7) comprise a pair of first pulleys (21, 21a) keyed to a horizontal drive shaft (22) and positioned laterally between the end of the deck (7) innermost in relation to the central frame (4) and the relative fixed beam (5a), and a pair of belts (23, 23a), the first extending substantially parallel to and beneath the deck (7) from the respective first pulley (21) to the outermost end of the deck, the second descending vertically and at right angles to the first from the respective first pulley (21a) to the innermost end of the deck, which are anchored by their opposite ends to the respective first pulleys (21, 21a) and to corresponding second pulleys (24, 24a) associated with the deck (7), and pass also around a plurality of relative third intermediate pulleys (25s) supporting the table (7b), of which at least one (25) is capable of movement internally of a channel (25a) and secured in a fixed position to the table (7b).
A platform as in claim 6, further comprising a gear (26) carried coaxially by the end of the horizontal drive shaft (22), adjacent to the deck (7) and meshing with a second gear (27) keyed to one end of a transmission shaft (28) mounted rotatably and extending transversely across the central frame (4), of which the remaining end connects by way of a third gear with an assembly comprising gear (26), horizontal shaft (22) and first pulleys (21, 21a) essentially identical to that of the opposite side in order to enable synchronized operation of the set of four belts (23, 23a).
A platform as in claim 1, wherein guide means (11) comprise a pantograph (30) associated with each longitudinal flank of each deck (7), accommodated internally of the deck itself with one end anchored to the central frame (4) and the opposite end anchored to and slidable in a slot (30a) afforded by the deck (7), and capable thus of movement between positions of minimum and maximum extension that coincide with the elevated and lowered limit positions of the deck (7).
A platform as in claim 6, further comprising a ramp (32) pivotably associated with the outermost edge of each deck (7), extending substantially across the entire available breadth and supported from beneath substantially at each end by a jacking strut (33) freely connected at one end (33a) to the crank arm (34a) of an operating lever (34) that is disposed parallel with the strut, pivoted at midpoint to the deck (7), and anchored rotatably at one end (34b) to the moving third pulley (25) associated with the outermost end of the table (7b) in such a way as to permit of angling the ramp (32) between a non-operative position, adopted in the elevated limit position of the deck (7), in which the face of the ramp is perpendicular to the deck and the strut (33) distanced from the ramp, and an operative position coinciding with the lowered limit position of the deck (7), in which the ramp is disposed at a given angle (α) in relation to the deck and the strut (33) substantially in contact with the ramp following rotation of the operating lever (34).
A platform as in claim 2, further comprising a reciprocrating double lever (55) affording control over the belt drive means (10), accommodated by and extending the full length of each side member (7a) and connected to the belt drive means (10) by each of its ends, which is embodied in two identical sections interconnected substantially in a central position by way of a perpendicularly disposed rocker arm (56) pivotably mounted at centre to the side member (7a) and impinging on the end of a locking rod (57), pivoted likewise to the side member (7a), which is embodied with a set of teeth (57a) offered to a matching set of teeth (58) associated with the guide means (11) and rotatable between a non-operative raised limit position, in which the sets of teeth (57a, 58) are distanced one from the other, and an operative lowered position in which the two sets of teeth (57a, 58) engage and lock the guide means (11), concurrently with the reciprocating movement of the relative section of the double lever (55).
A platform as in claim 2, wherein each of the side members (7a) is fitted at the end outermost with a retractable boot (38), and laterally with a first cloth (39) wound onto a first roller (39a) disposed parallel with and accommodated internally of the side member, by which the belt drive means (10) and the guide means (11) are afforded protection during movement of the deck (7) between the elevated limit position and the lowered limit position.
A platform as in claim 2, further comprising a second cloth (40) fitted to the innermost end of the table (7b), having one end anchored to a second roller (40a) mounted rotatably to the table and the opposite end to the central frame (4), by which a covering is provided between the innermost end of the table (7b) and the frame (4) during movement of the deck (7) between the elevated limit position and the lowered limit position.
A platform as in claim 1, of which the central frame (4), the two decks (7), the fixed beams (5a, 5b) and the corresponding drive means (6, 10) and guide means (11) together form a single unit incorporating means (41) for fastening to the first floor level (1a) of the carriage and of height (G) equal to the height (G1) of the existing carriage steps (GR).