Lifting device

Abstract

The present invention relates to a lifting system (1) for a wheelchair provided with an active, motor-driven drive system for a platform (2), and with a passive, non-motor-driven drive system for a gangway (3) movable between a rest position (P0) in a retracted state relative to the platform (2), and an active position (P1) in an extended state in front of the platform (2).<sb / > <sb / > The active, motor-driven drive system (10) is configured to move the platform (2) in height, and the passive, non-motor-driven drive system (11) is configured to automatically adjust a degree of extension (S) of the gangway (3) according to the height position (Pc) of the platform (2).

Description

[0001] LIFTING DEVICE

[0002] Technical field of the invention

[0003] The present invention relates to the field of freight elevators, and more particularly to lifting devices adapted for wheelchairs, baby strollers, or small trolleys.

[0004] State of the art

[0005] To enable elderly or disabled people to access different floors of a building, various devices such as stairlifts for wheelchairs or, for example, with a seat, are already available. Devices designed for wheelchairs generally include a mobile platform to support the wheelchair, as well as a motorized mechanism to move this platform up or down a ramp; alternatively, it can be operated by a hydraulic cylinder to move the platform from a lower level to a higher level by "skipping" a certain number of steps.

[0006] However, this type of device has the disadvantage of being very expensive, particularly because of the need for custom installation according to the shape of each staircase on which it is to be installed, and the provision of corresponding guide rails.

[0007] Furthermore, when it comes to providing a suitable platform to overcome an obstacle of only a few steps for private housing, for example for a house that is not built on one level, it is very difficult to create a standardized device adaptable to any height and depth of usual steps.

[0008] One aim of the proposed invention is to provide an exemplary solution to these known drawbacks.

[0009] Summary of the invention In particular, an object of the present invention is to provide a new solution for a wheelchair lifting system made at a lower cost, and which could be placed in as many homes as possible.

[0010] These goals are achieved according to the invention through the features of the main claim, and in particular through a wheelchair lifting system provided with a motorized active drive system for a platform, and a non-motorized passive drive system for a mobile walkway between a resting position in a retracted state relative to the platform, and an active position in a stretched-out state in front of the platform, the motorized active drive system being configured to move the platform vertically, and the non-motorized passive drive system being configured to automatically adjust a forward movement level of the walkway according to the vertical position of the platform.

[0011] One advantage of the proposed solution is that it significantly reduces costs by eliminating the need for a second motor dedicated to the gateway and also indirectly eliminating the need for power supplies, since the gateway is moved entirely by mechanical means and therefore does not require any additional electrical power supply.

[0012] Another advantage of the proposed solution is that it provides a simple and elegant solution suitable for various types of steps that may vary slightly in height and depth without requiring a custom solution each time.

[0013] In a preferred embodiment, the lifting system comprises a chassis with a platform access ramp and at least one first side railing. The motorized active drive system is integrated into the first side railing and jointly defines a maximum lifting height for the platform and a maximum extension stroke for the walkway, which is reached in the active position. In this way, not only is access to the platform facilitated, but safety is maximized throughout the platform's movement. Integrating the motorized active drive device into a railing saves space, and the correlation between the walkway's extension movement and the platform's height also allows for efficient calibration of the chassis's position relative to the steps that the lifting device is intended to span to provide access to a higher level.

[0014] According to another preferred embodiment of the lifting system according to the invention, the passive drive system of the platform includes means for elastically activating the walkway outwards, and means for returning the walkway inwards, the return means being formed by a cable of a fixed length.

[0015] The advantage of this proposed embodiment is that it requires only conventional tension and return elements to ensure the kinematic link between the platform and the walkway; however, it may be noted that the use of a cable as a return element and an elastic element as a tension element towards the outside of the platform may appear counterintuitive.

[0016] According to an even more preferred embodiment for the wheelchair lifting system according to the invention, the advancement level of said walkway is determined by a differential in the useful length of said cable, said to be of fixed length, between a first return roller attached to the platform and an attachment point of the walkway, the useful length of the cable, said to be of fixed length, depending on the distance between a first fixed attachment point of the cable, said to be of fixed length, and the first return roller attached to the platform.

[0017] Such a configuration allows the vertical movement of the platform to be transmitted in a particularly simple way into a translational movement of the walkway, thanks to purely geometric considerations. Indeed, the reduction in length between the attachment point of one end of the prestressed cable and the return roller, preferably located at the rear of the platform, when the platform is in its lowered position and when it gradually rises, corresponds exactly to a difference in the effective cable length that is released and thus directly determines the level of advancement of the walkway, which is simultaneously pulled forward by elastic means.

[0018] According to an even more preferred embodiment for the wheelchair lifting system according to the invention, the non-motorized passive drive system further comprises a translational guidance system for the walkway, which is formed by lateral rails each equipped with a plurality of guide rollers.

[0019] One advantage of this embodiment is that it allows for a particularly simple and inexpensive implementation of the invention.

[0020] According to yet another preferred embodiment of the wheelchair lifting system according to the invention, the non-motorized passive drive system also includes an indexing system to adjust the relative positioning between the walkway and the platform.

[0021] One advantage of this design is that it allows for fine-tuning the platform's positioning, particularly at the end of its travel, enabling adaptation to a wide range of step depths without requiring any other modifications to the lifting system, especially the frame's positioning, which is more delicate due to its weight. This adjustment can therefore be made last, once the entire system is permanently installed in the building.

[0022] According to another preferred embodiment which is even more advantageous, the wheelchair lifting system according to the invention provides for a plurality of fixing holes in each of the side rails.

[0023] In this way, it is possible to combine the guidance and indexing mechanisms at the level of the side rails efficiently and advantageously, making the assembly of the system even easier and less expensive.

[0024] According to an even more preferred embodiment, the wheelchair lifting system according to the invention is characterized in that the platform comprises a base plate, as well as a cover plate, the mobile walkway moving between the base plate and the cover plate in the manner of a drawer.

[0025] This embodiment allows, on the one hand, for the effective concealment of the non-motorized passive drive system, which is thus completely invisible from the outside, thereby improving the aesthetics of the proposed lifting device, and on the other hand, for optimal protection of the entire transmission mechanism against external elements, which cannot penetrate the confined space between these two plates, as the walkway prevents any access from the front of the platform. The walkway and all potentially attached guide elements, such as guide rails, are thus "sandwiched" between the two plates and move in and out of the platform like a drawer in and out of a chest of drawers.

[0026] According to an even more preferred embodiment for implementing the invention, the wheelchair lifting system according to the claim is characterized in that the elastic stress means are formed by a first spring, one end of which is fixed to the base plate and the other end is fixed to a first lateral rail, and a second spring, one end of which is fixed to the base plate and the other end is fixed to a second lateral rail.

[0027] Such a configuration allows for the advantageous use of the lateral rails not only as guide elements, but also as transmission elements that drive the outward movement of the walkway at the front of the platform; the force exerted by these springs also helps maintain the tension level of the prestressed cable. According to an even more preferred embodiment for the wheelchair lifting system of the invention, the non-motorized passive drive system further includes end stops for the mobile walkway that define a reduced maximum extension stroke, which is strictly less than the maximum extension stroke for the walkway's forward movement.

[0028] In such a configuration, a stopping mechanism can be defined to further limit the forward movement of the protruding walkway at the front of the platform before it reaches its active position. Since the walkway's maximum extension stroke is already limited by the platform's maximum travel height, this means that a reduced maximum extension stroke can be achieved, strictly less than the nominal maximum possible extension stroke. This allows for adjustments based on the specific requirements of the lifting system's installation location. Thus, the configuration possibilities of the proposed lifting device are increased. Furthermore, the simplified integration of the stops into the cover plate, thanks to functional synergies and parts savings, further reduces manufacturing costs.

[0029] According to an even more preferred embodiment for implementing the invention, the wheelchair lifting system is characterized in that a return system comprising four fixed rollers and one movable roller is provided to allow an excess length of cable to be housed in a cable magazine in a configuration where the advancement level of the walkway is limited to the maximum extension stroke reduced by the exit stops, and where the platform continues to be moved in height via the motorized active drive system.

[0030] In a configuration where the effective cable length is constant, and the difference in effective length between a fixed point (e.g., at the front of the platform) and a moving point (e.g., at the rear) determines the forward movement of the projecting walkway, this difference mechanically increases as the platform rises. However, since any further increase in the effective cable length, corresponding to an additional extension of the walkway, is prevented by the walkway's blocking due to the extension stops, it is advantageous to provide a mechanism for adjusting the cable length (corresponding to its effective length) within the platform to maintain its tension.According to the proposed preferred variant, this functionality is implemented as soon as the walkway reaches its reduced maximum extension stroke before reaching its active position when the platform's maximum height is reached. This improves the device's reliability, as the cable cannot derail between the various fixed deflection elements within the platform, particularly on the base plate.

[0031] According to an even more preferred embodiment for implementing the invention, the wheelchair lifting system is characterized in that the movable roller is guided in translation in the magazine by means of a slide sliding in a groove provided in a magazine rule, and is forced into movement in the magazine by a dedicated return spring.

[0032] In this configuration, any excess cable length generated after the walkway reaches its end stop is adjusted in a particularly simple way on the base plate. A movable roller, mounted like a tourbillon in a watch, is free-swinging on a sliding track, allowing it only one degree of translational freedom. This roller is automatically moved by the action of a dedicated return spring to absorb any excess cable length that would otherwise need to be stored within the system. This embodiment thus allows for a particularly simple and elegant management of any excess cable length generated when the walkway reaches its end stop, limiting its extension to a reduced maximum travel distance.According to another preferred embodiment for the implementation of the wheelchair lifting system according to the invention, the mobile walkway is terminated at its front end by a pivoting flap.

[0033] This configuration allows for the simple creation of a sort of adjustable exit ramp for the platform, thus achieving the smoothest possible height adjustment relative to the landing to be reached. Furthermore, it allows for this slight height adjustment to be made automatically when needed, which is particularly advantageous.

[0034] According to another preferred embodiment of the invention, the wheelchair lifting system is characterized in that it also contains a safety system integrated at the rear of the platform comprising a pivoting arch arranged to move between a horizontal position, in the lower position of the platform, where it is flush with the upper surface thereof, and an inclined position where a retaining bar protrudes above the platform.

[0035] Thanks to this configuration, the level of safety provided by the proposed lifting system is further improved, as the wheelchair can only move forward once the platform is raised. This is achieved without any negative impact on convenience and user comfort, since the pivoting bar is concealed in the lowered position of the platform when the wheelchair or any other component is loaded onto it. Beyond the practical advantages, this beneficial implementation of the invention can also facilitate compliance with safety standards that may be essential for market access in certain countries.

[0036] According to an even more preferred embodiment for the implementation of the wheelchair lifting system according to the invention, the safety system integrated at the rear of the platform comprises pivoting rods subjected to rotation by an activation spring, a first end of the pivoting rods being equipped with ground support wheels, while a second end of the pivoting rods includes a support surface adapted to support the lateral uprights of the pivoting hoop, the pivoting rods being movable between a horizontal position superimposed under the lateral uprights in the lower position of the platform, and an upright position in which the support surfaces support the lateral uprights of the pivoting hoop and maintain the latter in an inclined position.

[0037] Such a configuration allows for a particularly simple and automatic implementation of a safety device at the rear of the platform, still without requiring motorized actuation, but nevertheless preventing particularly effective any rearward movement of the wheelchair as soon as the platform leaves the ground, the hoop acting as a rear railing which is activated as soon as the wheels of the pivoting rods are no longer in contact with the ground.

[0038] Brief description of the drawings

[0039] Other advantageous features will become clearer from the following description of particular embodiments of the invention given by way of non-limiting example and represented by the accompanying drawings, in which:

[0040] - Figure 1A is a three-dimensional view of a lifting system according to a preferred embodiment seen from the front, with the extended walkway in an intermediate position between the rest position, i.e. in the retracted position, and the active position; Figure 1B illustrates, as a complement, the detail of the front of the walkway highlighting the extension stops formed to limit the extension of the latter in the active position, these stops being formed by retaining beaks and determining a reduced maximum extension stroke for the walkway;

[0041] - Figure 2A is a three-dimensional view of the lifting system of the preferred embodiment of Figure 1, this time seen from the rear, to highlight the safety device as well as the slides in the side railings provided for the movement of the platform and which determine the rest and active positions of the walkway respectively, i.e. in its extended state; Figure 2B shows the detail of the integrated safety system operated at the rear of the platform;

[0042] - Figures 3A and 3B are respectively a three-dimensional view of the inside of a railing where the active drive mechanism of the platform is housed, and a profile view of the lifting system according to the preferred embodiment illustrated in the previous figures, in the same intermediate position.

[0043] - Figure 4A is a 3D top view of the lifting system, highlighting the base plate of a mobile platform according to a preferred embodiment and a non-motorized passive drive system for the spring-loaded walkway; Figures 4B and 4C show the operating principle of a movable roller mounted on a slide inside a cable magazine, respectively according to a 3D side and top view;

[0044] - Figure 5 illustrates a diagram of the operation of the gateway exit up to a stop arrival as a function of the available cable length going against the elastic restoring force exerted by the springs;

[0045] - Figure 6 is a top view of a return system including a movable roller and a cable magazine designed to manage excess cable once the gateway has been extended to its stop;

[0046] - Figures 7A and 7B illustrate the detail of the integrated safety system provided at the rear of the mobile platform according to a preferred embodiment, Figure 8A being a top view of the platform showing the pivoting hoop in a horizontal position in the lower position of the platform and Figure 8B being a cross-sectional view of the rear of the platform showing the pivoting hoop in an inclined position as soon as the platform leaves the ground.

[0047] Detailed Description The following description describes a preferred embodiment of the invention, given by way of non-limiting example. For most figures, when a series of figures includes several different suffixes followed by the same number (for example 1 A-1 B, 2A-2B, 3A-3B-3C, 4A-4B-4C, 7A-7B), all the figures in the same series will be described together.

[0048] Figure 1A illustrates in three dimensions, from the front, a lifting system 1 according to a preferred embodiment comprising two safety railings, namely a first lateral railing 42 in which the motorized active drive system 10 is housed, and a second lateral railing 43, illustrated in detail later with reference to Figures 3A and 3B. In Figure 1A, the walkway 3 is extended in an intermediate position between the rest position Po, i.e., the retracted position, corresponding to the lower position PB of the platform 2, and the active position Pi, which corresponds to the upper position PH of the platform 2. The lower and upper positions PB,PH are visible in particular in Figures 3A and 3B which follow.

[0049] The extent of the extension of the walkway 3 between the respective rest positions Po and active Pi is illustrated in Figure 1B, which shows the detail of the front of the walkway 3, with its pivoting flap 33 mounted at the front around a hinge (not referenced) to allow slight height adjustment if needed, and whose advancement level S at the exit protruding towards the front of the platform 2 is precisely between the rest position Po and the active position Pi.

[0050] In Figure 1A, apart from the first side railing 42 and the second side railing 43, an integrated safety system 8 can be seen. This system prevents, for example, a wheelchair or other object placed on platform 2, or more precisely, the platform cover plate 22, from tipping backward when the platform is raised. As can be seen in Figure 1A, the first side railing 42 prevents any leftward movement in the direction of loading and unloading of platform 2, while the second side railing 43 prevents any rightward movement. However, when platform 2 is raised from its lower position PB to its upper position PH, any object placed on platform 2 would tend to move backward due to inertia, particularly when the motorized active drive system 1 is activated.These low PB and high PH positions of platform 2 illustrated in particular on figure 3B correspond to a positioning of the platform corresponding to a position against the bottom of each of the circular guide rails, that is to say at the rear of the first circular guide rail 420 of the first side rail 42, and at the front of the second circular guide rail of the first side rail 42, and similarly at the rear of the third circular guide rail 430 of the second side rail 43, and at the front of the fourth circular guide rail 431 of the second side rail 43.

[0051] This integrated safety system 81 is mainly made up of a pivoting hoop 81, formed of a retaining bar 810 and two lateral posts 810, the actuation mechanism of which will be described in more detail with the help of the figures 7A and 7B which follow.

[0052] In the foreground of Figure 1A, lateral rails 32 can be seen, specifically a first lateral rail 32A adjacent to the first lateral railing 42, i.e., on the left side of platform 2 in the loading and unloading direction and on the right side of the figure, and a second lateral rail 32B adjacent to the second lateral railing 42, i.e., on the right side of platform 2 in the loading and unloading direction and on the left side of the figure. These lateral rails 32A and 32B serve as guides in the direction of exit from the walkway. Also in the foreground of Figure 1A, the ends of a cable 60, acting as a restraint means 6 for the walkway, can be seen, along with its fixed attachment points 601 and 602, respectively attached to the frame 4 of the lifting device 1.It is precisely the fixed length of the cable, referred to as 60, which, according to the preferred embodiment described, enables the operation of the non-motorized passive drive system 11, allowing the exit of the walkway 3 to be actuated as the platform is raised. This passive drive system is integrated into the platform 2 and will be described later, particularly with reference to the series of figures 4A-4B-4C, the diagram in Figure 5, and Figure 6, which illustrate the correlation between the advancement level S of the walkway 3 at the front of the platform 2 and the height of the platform 2.

[0053] Each of the side rails, that is, the first side rail 32A and the second side rail 32B, has mounting holes 321, which allow not only for fixing each of these side rails 32A, 32B to the walkway 3, but also for adjusting the nominal output level of the walkway at rest. By convention, the walkway's forward travel level S can be considered zero in the rest position (i.e., S = 0). Each of the side rails is fixed to the walkway using mounting screws 322.

[0054] According to this variant, a translational guidance device for the walkway 3 can be advantageously implemented in conjunction with an indexing device 112 for determining its relative position with respect to the platform 2, both at rest and in the extended position, depending on the chosen fixing hole 321 (see the dashed arrow in Figure 1B to show the range of possible indexed length values, assuming that the screw 322 is inserted here into the last possible hole on the right). As will be seen later, particularly with reference to Figure 4A, the translational guidance system for the walkway preferably also includes guide rollers 320 mounted on each of the lateral rails 32A, 32B. In Figure 1A, these guide rollers 320 are concealed inside the platform 2.

[0055] Figure 1B consists of an enlargement of the front part of the left side of platform 2 and walkway 3, highlighting the type of outward stop preferably used to limit the extension of the latter in the active position Pi. As can be seen, these outward stops are formed here by retaining beaks 220 - each of the retaining beaks interacting with a corresponding lateral rail, i.e. the first retaining beak 220A with the first lateral rail 32A and the second retaining beak 220B interacting with the second lateral rail 32, determining a reduced maximum extension stroke for walkway 3 when the corresponding fixing screw 322 comes to rest against the corresponding retaining beak 220A,220B.

[0056] According to the preferred embodiment illustrated in Figure 1B, the second retaining beak 220B cooperating with the second lateral rail 32B (the first retaining beak cooperating with the first lateral rail 32A being visible only in Figure 1A, which is less detailed regarding this stop mechanism for the walkway 3) is fixed to the platform using another fixing screw 221, but any other method of fixing (by bending a part of the cover plate 22 of the platform 2, visible in Figures 1A and 1B, as well as by welding or other means).

[0057] According to an unillustrated variant, the exit stops can alternatively be formed by a first retaining beak 220A and a second retaining beak 220B which would always be arranged on the cover plate 22 of the platform, but with the first retaining beak 220A acting on a first guide roller 320 associated with the front of the first guide rail 32A, and similarly and the second retaining beak 220B acting on a second guide roller 320B associated with the front of the second guide rail 32B.

[0058] In such a configuration, it is always advantageous to combine guiding elements—the rollers attached to the side rails—with a stopping mechanism that can further limit the forward movement of the walkway relative to the platform, which is already restricted by the walkway's travel height. Furthermore, the simplified integration of the exit stops into the cover plate 22, thanks to the resulting functional synergies and parts savings, allows for a further reduction in the manufacturing costs of the proposed lifting device.

[0059] Regardless of the variant used to reduce the advance level of the walkway S, it is thus confined to a reduced maximum extension stroke C', which is less than the maximum extension stroke C that the walkway would have reached in the active position Pi when the platform 2 had reached its maximum height H in the raised position PH (illustrated respectively in Figures 5 and 3B). Once this reduced maximum extension stroke C' is reached by the walkway, an adjustment mechanism is necessary to ensure that the cable remains constantly taut, even when the platform continues to rise after the advance level S of the walkway 3 reaches the reduced maximum extension stroke C'. This mechanism will be described in more detail, particularly with reference to the series of Figures 4A-4C, which highlight the cable magazine provided for this purpose.

[0060] In the described embodiment, two side railings are used as a safety mechanism to prevent any fall to the left and / or right of the platform 2; it will be understood that it is possible to implement an elevation system 1 with a single side railing as a safety element, and for example with a wall as another side guardrail.

[0061] In the figures that follow, not all the references that have been described previously in figures 1 A-1 B will be repeated in detail, and we will focus on the characteristics that had not been described previously.

[0062] Figure 2A is a three-dimensional view of the lifting system 1 of the preferred embodiment of Figure 1, this time viewed from the rear, to highlight the access ramp 41 in addition to the integrated safety device 8 and the slides in the side railings.

[0063] The proposed lifting device can be used as a freight elevator; it is particularly suitable for wheelchairs, but it can also be considered for use with small trolleys, baby strollers, or other items.

[0064] As already explained with reference to Figures 1A-1B, the chassis 4 of the proposed lifting system 1 comprises two side rails: a first side rail 42 on the left, into which the motorized active drive system 11 is integrated (described later with reference to Figures 3A-3B), and a second side rail 43 on the right. Each of these rails 42 and 43 is provided with circular guide rails, specifically a first circular guide rail 420 at the front of the first side rail 42 and a second circular guide rail 421 at the rear of it, and similarly, a third circular guide rail 430 at the front of the second side rail 43 and a fourth circular guide rail 431 at the rear of the latter.These various slides (420, 421, 430, 431) are designed to allow the platform 2 to move according to a predetermined motion, both forward and upward. When the platform moves from bottom to top, the walkway 3, equipped with its pivoting flap 33, moves forward between a rest position Po and an active position Pi. It should be noted that, according to the described embodiment, the pivoting flap 33 is horizontal at rest and can only pivot upward to compensate for a slight height difference relative to a step to be reached at the exit. However, a non-zero, or even slightly negative, angle of inclination at rest could be determined. The pivoting flap 33 of the walkway thus provides a kind of adjustable exit ramp, complementing the access ramp 41 at the rear of the frame 4.

[0065] The proposed lifting device 1 being designed to perform a passage of a few steps, the simultaneous movement of the platform forward at the same time as it moves upwards is particularly suitable; the walkway 3 being then designed to fill in an adjustable way the gap remaining between the front edge of the platform and the top of the last step to be crossed.

[0066] However, a threshold effect of crossing an obstacle also occurs at the entrance of the lifting device 1, when trying to get onto the platform 2. This is why the access ramp 41 is provided at the entrance of the chassis 4, with the lowest possible inclination to avoid having to exert too much effort to pass the ramp.

[0067] The lifting device 1 shows the platform 2 in a position similar to that of the previous Figures 1A-1B, i.e., intermediate in height, between the low position PB of the platform 2 and the high position PH of the platform 2, as also indicated by the intermediate position of the platform 2 anchor points in the circular guide rails (420, 421, 430, 431). As soon as the platform leaves the ground, i.e., when the height position is different from the low position PB for the platform 2, the integrated safety device 8, consisting of a pivoting hoop 81, rises to prevent any backward movement of the wheelchair or any device placed on the platform 2 when the lifting system is activated.

[0068] As can be seen in Figure 2A, the integrated safety device is essentially formed by the pivoting hoop 81, itself formed of a retaining bar 811 and lateral uprights 810, mounted respectively pivoting around a first pivot axis 81A. In the raised position, the hoop 81, or more precisely the lateral uprights 810 of the hoop 81, come to rest against rods 82 which are themselves also pivoting around a second pivot axis 82A and are subjected to rotation by an activation spring 83 which is compressed when the platform 2 is in its lower position PB.This activation spring 83 is visible in Figure 2B, where we also see in more detail the lateral grooves 85 in which both the pivoting rods 82 and the lateral uprights 810 of the hoop 81 fit, which overlap one on top of the other, so as to be flush with the upper surface 20 of the platform, illustrated later in Figures 7A-7B, and with the help of which the activation mechanism of the integrated safety device 8 will be explained in more detail.

[0069] Figures 3A and 3B respectively show a three-dimensional view of the inside of the first side railing 42 where the motorized active drive mechanism 10 of the platform 2 is housed, and a profile view of the lifting system 1 according to the preferred embodiment illustrated in the previous figures, in the same intermediate position.

[0070] As can be seen in Figure 3A, the platform's active motorized drive system uses a single piston 100 common to two traction cables, namely the front traction cable 100A and the rear traction cable 100B. These cables are respectively connected, via linkages 102 (consisting, for example, of hollow rollers), to traction levers, specifically a front traction lever 10A and a rear traction lever 10B. The end of each of these levers is connected to a cable and moves in a circular guide groove.More specifically, the end of the front traction cable 100A is connected to the end of the front traction lever, which moves in the first circular guide slide 420 in front of the first side rail 42, while that of the rear traction cable 100B is connected to the end of the rear traction lever 10B, which moves in the second circular guide slide 421 in rear of the first side rail 42. When the piston 100 simultaneously pulls both the front traction cable 100A and the rear traction cable 100B, the latter pull their respective traction levers, i.e. the front traction levers 10A and 10B, causing them to pivot to the left.During this operation, the two front and rear traction cables (100A & 100B) remain guided by a respective arc-shaped guide piece, namely the front guide piece 101A for the front traction cable 100A and the rear guide piece 101B for the rear traction cable 100B. Since both guide pieces and grooves have the same shape, the winding length of each of the traction cables 100A and 100B is identical, and it is possible to perform this platform lifting operation with a single common piston 100, thus minimizing costs.

[0071] Figures 3A and 3B still illustrate platform 2 in an intermediate height position, as in the previous figures. However, Figure 3B allows us to visualize the low position PB and high position PH of platform 2, each of these positions corresponding to a positioning of the ends of each of the levers associated with the motorized active drive system 10 of platform 2 at one end of its respective circular guide rail, as well as the current height position Pc, somewhere between the two ends of the circular guide rails (here the third and fourth circular guide rails 430 and 431, respectively), therefore in an intermediate position similar to that illustrated in the previous figures.In Figure 3B, it can be seen that we are no longer dealing with the traction levers associated with the cables, but with passive levers inserted into the other railing, that is, the second lateral railing 43. These passive levers are connected to their respective active levers via beams that cross transversely through platform 2, forming rigid arches (similar to the pivoting arch 81, with the levers then forming the uprights of this arch) supporting the platform at the front and rear. These beams are not shown in the figures, however, as they are hidden inside platform 2.We can therefore distinguish in figure 3B a front passive lever 10C, connected to the front active lever 10A at the front of platform 2, and a rear passive lever 10D, connected to the rear active lever 10B at the rear of platform 2; each of the front-rear lever pairs respectively 10A-10C and 10B-10D are arranged in the same angular position inside their respective circular guide slides 420-430 and 421-431.

[0072] While Figures 3A and 3B explain how platform 2 moves simultaneously upwards and forwards by means of the motorized active drive system 10, the following series of Figures 4A-4C now focuses on the non-motorized passive drive system 11 which is configured to automatically adjust the advance level S of walkway 3 according to the current height position Pc of platform 2.

[0073] Figure 4A is a three-dimensional top view of the lifting system 1 according to a preferred embodiment of the invention, highlighting the base plate 21 of a movable platform 2 on which the unpowered passive drive system 11 of the walkway 3 is housed. This unpowered passive drive system 11 is preferably concealed beneath the cover plate 22 of the platform 2, and the walkway 3 moves back and forth between the base plate 21 and the cover plate in a drawer-like fashion. The side rails 32, or more precisely the first left side rail 32A and the second right side rail 32B, to which two guide rollers 320 are attached on each side, are the integral elements of the walkway 3 that move between the base plate 21 and the cover plate 22. The operation of the unpowered passive drive system 11 is as follows.The cable 60, visible in the middle of Figure 4A, and its attachment point 31, or the point at which the walkway 3 is held in its retraction direction, are used. Elastic force means 5 exerting outward pressure are used to move the walkway from its rest position Po to its active position Pi. In the illustrated embodiment, the elastic force means 5 consist of a first spring 51, one end 511 of which is fixed to the base plate 21 and the other end 512 of which is fixed to the rear of the first lateral guide rail 32A. The fact that a first fixed return wheel 217 is located at the front of the platform means that this spring exerts a restoring force that tends to move the walkway 3 forward of the platform 2.The second end 512 of the first spring 51 is therefore translationally movable and tends to pull the first guide rail 32A outwards. Similarly, according to axial symmetry, a second spring 52 is used to form the elastic load means 5 to the right of the base plate 21, that is, with a first end 521 fixed to the base plate 21 and a second end 522 fixed to the rear of the second lateral guide rail 32B. Thanks to the use of the second fixed return wheel 218 also located at the front of the platform, the second end 522 of the second spring is also translationally movable relative to the platform and tends to pull this second guide rail 32B outwards as well. In the end, the elastic means of stressing 5 formed by the first return spring 51 and the second return spring 52 exert a first restoring force F1 in tension of the walkway 3 outwards.

[0074] This first restoring force F1 is however compensated by a second restoring force F2 consisting of the tensile force of the presumed cable 60, which is used as a restoring means 6 to maintain the walkway in its retracted position towards the inside of the platform 2. As can be seen in figure 4A, the presumed cable runs on one side of the base plate 21 in a straight line and on the other, via a series of rollers constituting a return system 210.The return system 210 is specifically formed of five rollers, including four fixed rollers (211, 212, 214, 215) and a movable roller 213 – the third roller in the series – which can move within a guide 70 of a cable magazine 7. This movable roller is designed to compensate for a difference in the cable's usable length as soon as the walkway 3 reaches its end stop, thus determining a reduced maximum extension stroke C' that is strictly less than the maximum extension stroke C when the platform reaches its upper position PH. The return system 210 is also detailed in Figure 6 below, and Figures 4B and 4C show the operating principle of a movable roller 213 mounted on a slide 72 inside a cable magazine 7, respectively, in a three-dimensional side and top view.But before detailing the cable length recovery mechanism, it is first necessary to understand how the automatic adjustment system for the elongation level S of gateway 3 works when it is not yet blocked by any stop.

[0075] This is explained by Figure 5, which illustrates a diagram of the operation of the gateway 3 output as a function of the alleged cable length 60 available and which acts against the elastic restoring force exerted by the springs, i.e. the first restoring force F1 in outward pull, visible in Figure 4A.

[0076] As can be seen in Figure 5, the cable length between the fixed points of the frame 601 / 602 and the return rollers 219A / 219B [schematically indicated here by reference numeral 219 for simplicity – the first and second return rollers 219A and 219B respectively being visible in Figures 4A and 6], which are movable relative to the frame 4 at the rear of the platform 2, varies between a first distance D1 in the raised position PH of the platform 2 and a second distance D2 in the lowered position PB of the platform 2. Since the maximum height H is reached in the raised position PH, this height is equal, given the particular shape of the circular guide rails, to the radius R of these rails. Considering that the platform has a length P, we therefore have the inequality D2 > D1 because:

[0077] D1 = / H2 + P2 while D2 = H + P Therefore, the differential in useful cable length A (Lu) between the low position PB and the high position PH of platform 2 is equal to the difference D2- D1, and corresponds to the elongation level S of the walkway, which is theoretically equal to the maximum elongation stroke C in the high position.This maximum extension stroke C is necessarily less than the maximum height H for platform 2 for obvious geometric reasons (a circle with center 601 / 602 and radius D1 will intersect the horizontal axis between a distance P and P+H corresponding to D2, but therefore the difference between D2 and D1 is necessarily strictly less than H), but as illustrated in Figure 5, if the extension level S of the platform at the exit is limited to a reduced maximum extension stroke C' strictly less than C, then the cable claimed 60 would tend to relax as soon as the walkway reaches its abutment as in the configuration illustrated in Figure 1A, because the difference in useful length of cable A (Lu) would then no longer be strictly equal to the extension level S at the exit of walkway 3.In other words, the balance between the first restoring force F1 pulling the footbridge outwards and the second restoring force F2 exerted by the alleged cable 60 tending to retract the footbridge 3 is broken and the alleged cable 60 therefore tends to relax.

[0078] It is precisely at this moment that the third restoring force F3 exerted by the dedicated restoring spring 71 of the movable roller 213 in the rule 70 of the cable magazine 7 takes over.

[0079] Indeed, since the differential in the useful cable length A (Lu) continues to increase in the plane of platform 2, but this cannot be achieved by an increase in the elongation level S of the walkway, this additional length must be recovered somewhere in the non-motorized passive drive system 11 arranged on platform 2. When the first strand of the cable, 60, arriving from a first fixed point 602 attached to the front of the chassis – visible in Figure 1A – is returned via the first roller 219A and the second roller 219B to the return system 210, it is then redirected by a first roller 211 located immediately next to the 2 e roller 219B, and in the sequence a second roller 212, a third movable roller 213, a fourth roller 214 and a fifth roller 215 before continuing onto the attachment point 31 of the gangway 3 and being returned to the 2 eroller 219B is then redirected to the second fixed point 602. The portion of the cable, 60, between the attachment point on the walkway can then be considered as constituting a second strand. In the redirection system 210, all the rollers (211, 212, 214, 215) are fixed, and only the third roller is a movable roller 213, which therefore allows the excess length (LE) to be recovered. This excess length is defined as the difference between the useful length differential A (Lu) of the cable and the reduced maximum elongation stroke C', provided that the elongation level S of the walkway is limited to this value. In this case, we have the following equality:

[0080] LE = A (Read) - C'

[0081] According to the preferred embodiment described, the movable roller 213 is provided to allow an excess length of cable (LE) to be housed in a cable magazine 7. As soon as the advance level S of the walkway 3 is limited to the reduced maximum extension stroke C' by the exit stops 220A,220B visible in Figures 1A and 1B, and where the platform 2 continues to be moved vertically via the motorized active drive system 10 described with reference to the preceding Figures 3A-3B, the movable roller 213 is driven by its dedicated return spring 71, visible in all Figures 4A-4B-4C, in translation under the action of a third return force F3, in the same direction as the first return force F1 and via a configuration similar to that of the first and second springs 51,52 used as elastic loading means 5 to pull the walkway outwards.Indeed, the dedicated return spring 71 is fixed to the platform 2 via a first fixed end 711, and returned via a deflection pinion 73 to a slide 72 attached to a second movable end 712. The slide 72 is mounted to slide in a groove 701 of the cable magazine guide 7. The movable roller 213, so named because of its degree of translational freedom in the cable magazine guide 70 under the action of the third return force F3, is mounted to rotate freely on the slide 72. In this configuration, the movable roller 213 is mounted "flying" on the guide 70, which acts as a bridge. This preferred embodiment thus requires no special modifications to the platform 2.However, according to one variant, it would be possible to provide a guide groove for the axis of the movable roller 213 in the platform 2 as well as another, thinner guide groove in the rule to guide the other end of the axis of the movable roller, i.e. its upper end.

[0082] In Figures 4B and 4C, the movable roller 213 is shown in an intermediate position in the rule 70, meaning that the excess cable is non-zero and that the walkway 3 has already reached its end stop and its reduced maximum extension stroke C', which will correspond to its active position Pi when the platform reaches its maximum height PH. The third restoring force F3, acting on the movable roller 213 in the magazine 7 under the action of the dedicated return spring 71, nevertheless appears in opposite directions between Figures 4B and 4C due to the different viewing angles for these figures.

[0083] Figure 6 is a top view of the lifting system 1 showing the platform 2 without the cover plate 22, i.e. to highlight all the different functional modules of the non-motorized passive drive system 11 of the platform on the base plate 21 of the platform, and which will then be hidden under the cover plate 22.

[0084] Figure 6 is similar to Figure 4A, but it is oriented according to a view from the rear of the chassis 4 (respectively of the platform), and thus in the direction of extension of the walkway 3, under the action of the first restoring force F1 exerted by the first restoring spring 51 and the second restoring spring 52 arranged symmetrically on the base plate 21.This figure highlights the symmetrical arrangement of the rails along the axis of movement of the platform 2 and the walkway 3 on either side of the platform (first lateral guide rail 32A and second lateral guide rail 32B on the right, with their respective associated guide rollers), leaving sufficient space in the center of the base plate 21 to accommodate the first and second springs 51, 52, as well as the return system 210 comprising a movable roller 213 and the cable magazine 7 designed to manage excess cable LE once the walkway has been fully extended and reaches its reduced maximum extension stroke C'. It should be noted that the second restoring force F2 exerted by the cable 60 is in the opposite direction to that of the first restoring force F1, but that the third restoring force F3 is, conversely, again in the same direction as the first restoring force F1.

[0085] All the elements of chassis 4 (side railings 42,43 as well as the circular guide rails etc.) as well as the non-motorized passive drive system 11 having already been explained in detail with the help of the previous figures, they will not be explained again in detail here within the framework of this figure, which aims to show synthetically all the associated functional modules which compose it, namely the translational guidance system - formed by the lateral rails 32A,32B - the indexing system 112 for adjusting the relative position between the walkway and the platform at rest, formed here by the fixing holes 321 on the rails, as well as the elastic force means 5 for pulling the walkway 3 outwards, composed of the first return spring 51 and the second return spring 52, which are balanced or compensated by the return means 6 for the walkway 3, formed by the cable 60 which exerts a second return force F2 in the opposite direction to the first return force F1.And finally, the cable store 7 with its length compensation system when the gateway 3 is brought to a stop before the platform reaches its maximum height H.

[0086] It can simply be noted in figures 4A and 6 that spacers 25 are provided on either side of the base plate 21, and arranged symmetrically as reinforcement elements intended to be placed under the cover plate 22, in order to support the weight of relatively heavy trolleys or people without generating any indentation in the latter, and thus damaging the entire non-motorized passive drive system 11 of the walkway 3.

[0087] The proposed solution for the lifting system described above defines a kind of "master-slave" system to condition the movement of walkway 3 as an auxiliary to that of platform 2, without requiring dedicated, bulky and expensive motorized drive means for walkway 3. The latter thus moves outwards towards the front of platform 2 in conjunction with the vertical movement of the latter, with possibilities of adjusting the maximum possible extension level outwards at the front of the platform to fill the gap necessary to reach the edge of the last step to be crossed.

[0088] Finally, figures 7A and 7B illustrate the detail of the integrated safety system 8 provided at the rear of the mobile platform 2 according to a preferred embodiment, figure 7A being a top view of the platform showing the pivoting hoop 81 in horizontal position in the lower position of the platform and figure 7B being a cross-sectional view of the rear of the platform 2 showing the pivoting hoop 81 in inclined position Pi as soon as the platform 2 leaves the ground, or more precisely its lower position PB.

[0089] Firstly, it should be noted that the proposed integrated safety system 8 consists of a completely independent module, arranged at the rear of platform 2, and which can be implemented in a completely independent manner from the other characteristics of the proposed lifting system 1, and in particular from the motorized active drive system 10 planned for platform 2 and the non-motorized passive drive system 11 planned for walkway 3.

[0090] As illustrated in Figure 7A, the integrated safety system 8 located at the rear of the platform 2, behind the cover plate 22, is designed to be concealed or hidden while the platform 2 is in its lowered position PB. The pivoting arch 81, formed by the retaining bar 811 and the two side posts 810, can be seen in the horizontal position. The side posts 810 are positioned in the lateral guides 85 above pivoting rods 82 – not visible in Figure 7A, but visible further on in Figure 7B – so as to be flush with the upper surface 20 of the platform 2. Once the trolley, or for example the wheelchair, has been loaded onto the platform 2 via the access ramp 41, the integrated safety system 8 is designed to prevent any rolling back, particularly when the motorized active drive system 10 of the platform 2 is activated.The illustration in Figure 7B shows how this integrated safety system 8 is automatically activated as soon as the platform 2 leaves its lower position PB to reach any current height position Pc (Pc ^ PB). At that moment, the activation spring 83, which was compressed when the pivoting rod 82 was in the horizontal position, can be released and bring the latter to the upright position PR, which simultaneously brings the lateral post 810 of the hoop 81 to the inclined position Pi, so that the hoop's retaining bar 811 can be functional and prevent any backward movement. It may be noted that both the pivoting rods 82 and the lateral uprights 810 of the hoop are mobile in rotation around the respective pivot axis, namely the first pivot axes 81 A for the lateral uprights 810 of the hoop 81, and the second pivot axis 82A for the pivoting rods 82.During its pivoting movement, the pivoting rod 82 slides under the lateral post 810 of the hoop 81 until it reaches a limiting stop 26 arranged, for example, directly in the platform 2 as a retaining beak, which acts as a rotation stop. According to the preferred embodiment illustrated in Figure 7B, the angle of inclination of both the lateral post 810 in the inclined position Pi and the pivoting rod 82 in the upright position PR are approximately 45°, such that the lateral post 810 of the hoop can be placed, at a right angle, on a support surface 822A at the upper end 822 of the pivoting rod 82; at its lower end 811, on the other hand, rollers 84 are provided to facilitate the bearing of this end on the ground without generating undue wear.

[0091] Thus, according to the proposed configuration for the integrated safety system 8, as soon as the platform 2 leaves the ground, the restoring force exerted by the compression spring 83 on the pivoting rod 82 instantly returns the rod to the upright position PR, and simultaneously moves the corresponding lateral support 810 of the hoop 81 to an inclined position Pi, so that the restraint bar 811 is active by protruding from the platform 2. This simple and elegant solution also provides an additional guardrail, completely automatically, reinforcing the safety provided, particularly for elderly people. It will be understood from this detailed description that the advantageous features derived from the preferred embodiments and the alternative variants described may be considered individually or in combination without departing from the scope of the invention, except when they are presented as mutually exclusive.

Claims

Demands 1. Wheelchair lifting system (1) having a motorized active drive system for a platform (2), and a non-motorized passive drive system for a walkway (3) movable between a rest position (Po) in a retracted state relative to said platform (2), and an active position (Pi) in a prone state in front of said platform (2), said motorized active drive system (10) being configured to move said platform (2) vertically, and said non-motorized passive drive system (11) being configured to automatically adjust a forward position (S) of said walkway (3) according to the vertical position (Pc) of the platform (2).

2. Wheelchair lifting system (1) according to claim 1, characterized in that it comprises a chassis (4) provided with an access ramp (41) to said platform (2), as well as at least one first side railing (42), said motorized active drive system (10) being integrated into said first side railing (42) and jointly defining a maximum lifting height (H) for said platform (2) as well as a maximum extension stroke (C) of the advancement level (S) of said walkway (3) in active position (Pi).

3. Wheelchair lifting system (1) according to any one of the preceding claims, said passive drive system (11) of said platform (2) comprising means for elastically applying (5) of said walkway (3) outwards, and means for returning (6) of said walkway (3) inwards, said return means (6) being formed by a cable alleged to be of fixed length (60).

4. Wheelchair lifting system (1) according to claim 3, the advancement level (S) of said platform (3) being determined by a differential (A) of usable length (Lu) of said alleged fixed-length cable (6) between a first return roller (219A) integral with said platform (2) and an attachment point (31) of said platform (3), said useful length (Lu) of said alleged fixed length cable (6) depending on the distance (D) between a first fixed attachment point (601) of said alleged fixed length cable (6), and said first return roller (219A) attached to said platform (2).

5. Lifting system (1) for wheelchair according to claim 4, non-motorized passive drive system (11) further comprising a translational guidance system for said walkway (3), said translational guidance system being formed by lateral rails (32) each provided with a plurality of guide rollers (320).

6. Wheelchair lifting system (1) according to claim 4 or 5, said non-motorized passive drive system (11) further comprising an indexing system for adjusting the relative positioning between said walkway (3) and said platform (2).

7. Wheelchair lifting system (1) according to claim 6, where it depends on claim 5, a plurality of fixing holes (321) being provided in each of said side rails (32).

8. Wheelchair lifting system (1) according to any one of claims 4 to 7, characterized in that said platform (2) comprises a base plate (21) and a cover plate (22), said mobile walkway (3) moving between said base plate (21) and said cover plate (22) in the manner of a drawer.

9. Wheelchair lifting system (1) according to claim 8, when it depends on claim 5, characterized in that said elastic stress means (5) are formed by a first spring (51) of which a first end (511) is fixed to said base plate (21) and a second end (512) is fixed to a first lateral rail (32A), and a second spring (52), of which a first end (521) is fixed to said base plate (21) and a second end (522) is fixed to a second lateral rail (32B).

10. Wheelchair lifting system (1) according to any one of the preceding claims, characterized in that said non-motorized passive drive system (11) further contains exit stops (220A,220B) for said mobile platform (3) defining a maximum reduced extension stroke (C') strictly less than said maximum extension stroke (C) for the advancement level (S) of said platform (3).

11. Wheelchair lifting system (1) according to claim 10, characterized in that a return system (210) comprising 4 fixed rollers (211, 212, 214, 215) and a movable roller (213) is provided to accommodate an excess length of cable (LE) in a cable magazine (7) in a configuration where the advance level (S) of said walkway (3) is limited to said reduced maximum extension stroke (C') by said exit stops (220A, 220B) and where said platform (2) continues to be moved in height via said motorized active drive system (10).

12. Wheelchair lifting system (1) according to claim 11, characterized in that said movable roller (213) is guided in translation in said magazine (7) by means of a slide (72) sliding in a groove (701) provided in a rule (70) of said magazine (7), and forced into movement in said magazine (7) by a dedicated return spring (71).

13. Wheelchair lifting system (1) according to any one of the preceding claims, said mobile walkway (3) terminates at its front end by a pivoting flap (33).

14. A wheelchair lifting system (1) according to any one of the preceding claims, characterized in that it further contains an integrated safety system (8) at the rear of said platform (2) comprising a pivoting bar (81) arranged to move between a horizontal position, in the lowered position (PB) of said platform (2), where it is flush with the upper surface (20) of said platform (2), and a inclined position (Pi) where a retaining bar (811) protrudes above said platform (2).

15. Wheelchair lifting system (1) according to claim 14, said safety system integrated (8) at the rear of said platform (2) comprising pivoting rods (82) rotated by an activation spring (83), a first end (821) of said pivoting rods (82) being equipped with ground support casters (84), while a second end (822) of said pivoting rods (82) comprises a support surface (822A) adapted to support lateral uprights (810) of said pivoting frame (81), said pivoting rods (82) being movable between a horizontal position superimposed under said lateral uprights (810) in the lowered position (PB) of said platform (2), and an upright position (PR) in which said support surfaces (822A) support said lateral uprights (810) of said pivoting frame and maintain the latter in an inclined position. (Pi).

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