EP3145849A1

EP3145849A1 - Stairlift

Info

Publication number: EP3145849A1
Application number: EP15733883.1A
Authority: EP
Inventors: Marco LORETI
Original assignee: ANTANO GROUP Srl
Current assignee: ANTANO GROUP Srl
Priority date: 2014-05-20
Filing date: 2015-05-20
Publication date: 2017-03-29
Anticipated expiration: 2035-05-20
Also published as: JP6687606B2; CN106687095A; WO2015177625A1; EP3145849B1; JP2017523008A; CN106687095B

Abstract

Stairlift (1) comprising a frame (2) provided with at least one unit (3) for raising, or lowering, said stairlift along the stairs (100) having a plurality of bearing surfaces (100a, 102a, 103 a, 100b) and at least one couple of wheels for the sliding of said stairlift, said at least one unit (3) comprising at least one first foot (4) movably constrained to said frame (2), directly or indirectly, in order to raise, or lower, said stairlift (1) along said stairs (100), characterized in that said at least one first foot (4) is shaped so that to be contemporaneously in contact with at least two bearing surfaces (100a, 102a; 102a; 103a; 103a, 100b) of said plurality of bearing surfaces (100a, 102a, 103 a, 100b) placed at different heights, during at least part of the raising, or lowering, of said stairlift (1) along said stairs (100).

Description

"Stairlift"

***

DESCRIPTION FIELD OF THE INVENTION

The present invention relates to a stairlift.

In particular, the stairlift concerned is employed for raising, or lowering, disabled people along straight o spiral stairs. More in detail, such stairlifts are also advantageously used for raising, or lowering, normal wheelchairs that disabled people use for their displacements.

KNOWN BACKGROUND ART

Stairlifts that comprise a frame, a unit for raising, or lowering, the stairlift itself along the stairs, and a couple of wheels for the sliding of the stairlift on an upper, or lower floor, with respect to the stairs, when the raising, or lowering step, of said stairlift along the stairs is finished, are known in the art. The above mentioned sliding means comprise wheels conveniently arranged at the base of the frame.

For example the Patent ITMC2008A043, in the name of the Proprietor, describes a stairlift provided with a frame to which two cranks rotatable by 360° are linked. For the displacement of the stairlift, at the free ends of the two cranks two idle wheels are pivoted in correspondence to their center. When the stairlift is in proximity of a step, the two cranks are rotated by 360°, so that the respective wheels are placed on the bearing surface of the step itself. Continuing in the rotation of the two cranks, the two wheels begin to raise the stairlift itself, thus being employed as means for raising of the stairlift itself.

Such a stairlift, although very simple and extremely effective, requires that an expert operator is always present which, positioning himself at the back part of the stairlift, keeps in balance the stairlift both during the raising and the lowering steps of the stairlift along the stairs.

Also, the Patent ITPG2010A000034 still in the name of the Proprietor, describes a stairlift of the kind comprising at least one unit to raise, or lower, said stairlift from the lower or upper landing, to the upper or lower landing, of a step of stairs. Such a raising/lowering unit comprises a first foot rotatably constrained with respect to the frame of the stairlift and, during part of the rotation, is directly or indirectly gripped on a first area of the upper landing of the step for raising, or lowering, the stairlift. ' Furthermore, such a raising and/or lowering unit is provided with a second foot that is roto-translatable with respect to the stairlift and, during part of its roto-translation, is directly or indirectly gripped on a second area of the lower landing of the step for raising, or lowering, the stairlift, and with synchronizing means to roto-translate the first foot and the second foot when gripped.

Such a stairlift, however, has some drawbacks. First of all, the second supporting foot proves to be extremely bulky when the stairlift must slide along a bearing plane different from that one of a step of stairs such as, for example, a flat surface above or underneath the stairs itself. With such a purpose the synchronizing mechanism, as well as the first and second supporting foot, must be shaped and dimensioned so that both the first foot and the second foot adopt, when non-working, a position raised with respect to the same bearing plane because they otherwise would always be pushing, i.e. the stairlift would always be raised or lowered when on the sliding plane.

Furthermore, such a solution doesn't prove to be completely independent of an expert operator obliged to keep the stairlift in balance during the raising or lowering of the stairlift along the stairs, in particular when the stairlift, with its couple of sliding wheels, reaches the landing of a step of the stairs.

Therefore, object of the present invention is to implement a stairlift structurally simpler than those of the known art and, at the same time, provided with a raising/lowering unit assuring the full stability of the stairlift in each step of the stairlift ascent or descent along the stairs.

Also, object of the present invention is to implement a stairlift provided with a raising, or lowering unit, which is space-saving, mainly in switching from raising and lowering step to the simple sliding step along any flat surface above or underneath the stairs. Further object of the present invention is to implement a stairlift not making broad use of electrical/electronic components for its raising or lowering functions, but being almost completely mechanical.

SUMMARY OF THE INVENTION These and other objects are achieved by a stairlift comprising a frame provided with at least one unit for raising, or lowering, said stairlift along the stairs and with at least one couple of wheels for the sliding of said stairlift along a plane, said at least one unit comprising at least one first foot movably constrained to said frame, directly or indirectly, in order to raise, or lower, said stairlift along said stairs, characterized in that said at least one first foot is shaped so that to be contemporaneously in contact with at least two bearing surfaces of said stairs which have different heights, during at least part of the raising, or lowering, of said stairlift along said stairs.

Practically, according to the invention the stairlift, during its-raising, or lowering step, is always contacting at least two landings of two following steps in order to improve the stability of the stairlift during the ascent and descent along the stairs. This is obtained by conveniently shaping said at least one first foot.

According to a particular embodiment of the invention, said at least one first foot is L- shaped so that it can touch, with at least two different areas preferably arranged at the free ends of the "L", the landings of two different and consecutive steps. According to a preferred embodiment, the free ends of the first foot comprise at least one cylindrically shaped abutment element.

According to the invention, said at least one raising, or lowering, unit comprises at least one first crank hinged in a first point to said frame, at least one second crank hinged in a second point to said frame, wherein said at least on first foot is rotatably constrained to said at least one first crank and said at least one second crank. Therefore, ultimately, said frame, said at least one first crank, said at least one second crank and said at least one first foot define a fpur-bar linkage so that, during the raising or lowering of the stairlift along the stairs, the first foot itself could perform a roto- translation by 360° with respect to the frame following the driven rotation of one of the two cranks. The driven rotation can occur, for example, thanks to the presence of an electric, or hydraulic, or other kind of motor that drives such a crank to rotate. Therefore, the proposed solution also allows to solve the problems that would happen in case the steps of the stairs were placed at non-constant heights, since the free rotation of the first foot with respect to the first and second crank allows to adjust its inclination so that it could always keep contact to the bearing surfaces of two different steps, at least when the stairlift is in the air phase, that is, the couple of sliding wheels and the frame are completely raised from any bearing surfaces.

According to the invention, said at least one raising/ lowering unit further comprises at least one second foot movably constrained, directly or indirectly, to said frame, and at least one mechanism for synchronizing the displacement of said at least one second foot with respect to said at least one first foot during at least part of the raising, or lowering, of said stairlift along said stairs, said at least one second foot, under the control of said at least one first foot and thanks to said synchronizing means, varies its own angular position with respect to at least one bearing surface of said plurality of bearing surfaces of said stairs and, depending on the direction of the force each second foot is subject to, at least when contacting a bearing surface of said stairs or the rise of a step of said stairs, is subjected to a moment adapted either to block it in position, in order to support said stairlift at least when said at least one first foot is not contacting said at least two bearing surfaces placed at different heights, or to push it towards a bent position, for the sliding of said stairlift.

Still according to the invention, said at least one second foot, under the control of said at least one first foot and thanks to said synchronizing means, thus varies its own angular position with respect to at least one bearing surface of said plurality of bearing surfaces between a first angular position and a second angular position so that:

- at least when contacting said at least one bearing surface in said at least one first angular position, it is subjected to a moment adapted to block it in position, in order to support said at least one stairlift at least when said at least one first foot is not contacting said at least two bearing surfaces placed at different heights; and

- - at least when contacting said at least one bearing surface in said second angular position, it is subjected to a moment adapted to push it towards a bent position, for the sliding of said stairlift.

Therefore, practically, when the second foot comes in contact with a bearing surface in said first position, the second foot is subject to a moment that keeps it blocked in position preventing any further forward displacement of the stairlift and, furthermore, such a second foot acts as a support during the repositioning of said at least one first - foot on two surfaces having different heights, that is, when said at least one first foot is not really contacting said at least two different surfaces. Conversely, when the second foot meets a bearing surface in said second position, it is subject to an opposite moment that leads it to a bent position in order to not hinder the sliding of the stairlift on the upper or lower surface of the stairs.

In the same way, when the second foot comes in contact with the rise of the last step of the stairs, also in said first position, and the stairlift is set back, it is however subject to a moment that leads it to bent position in order to not hinder the sliding of the stairlift on the upper surface of the stairs. Therefore, indeed, such a second foot not only makes more stable the stairlift during the raising, or lowering step, of the stairlift along the stairs, that is, in the air phase of the stairlift, but also it is able to bend to aid the sliding of the stairlift along an upper or lower landing of the stairs. In such a way it is avoided that the raising, or lowering unit, encumbers or hinders the sliding of the stairlift itself. In a further embodiment, at least when said at least one second foot is contacting said at least one bearing surface and subject to a moment adapted to block it in a stable position, in order to support said stairlift at least when said at least one first foot is not contacting said at least two bearing surfaces placed at different heights, said at least one couple of sliding wheels is contacting an additional bearing surface placed at a height different from said bearing surface for said at least one second foot. In particular, at least when said at least one second foot is contacting said at least one bearing surface and is in said first angular position, said at least one couple of sliding wheels is contacting an additional bearing surface placed at a height different from said bearing surface for said at least one second foot. This solution causes that in any step of the raising, or lowering, and therefore also when said at least one first foot is raised from the ground to reposition itself at two further bearing surfaces placed at different heights, the stairlift is always contacting two bearing surfaces placed at different heights, so that the maximum stability of the stairlift is guaranteed in any step of the raising.

In detail, said at least one second foot is rotatably constrained with respect to said frame and, at least when is not contacting said at least one bearing surface, carries out a reciprocating rotatory motion between said first angular position and said second angular position, and vice versa, being driven by said at least one first foot that preferably carries out a roto-translation. Preferably, between said first angular position and said second angular position, said at least one second foot passes through a vertical position. Furthermore, said at least one second foot is arranged in a front position with respect to said at least one first foot.

According to a further embodiment of the invention, said synchronizing mechanism comprises means for driving the synchronized displacement between said at least one first foot and said at least one second foot, at least when said at least one second foot is not contacting said at least one bearing surface, and for precluding the synchronized displacement between said at least one first foot and said at least one second foot, at least when said at least one second foot, contacting said at least one bearing surface, or the rise of the last step of said stairs, is subject to a moment adapted to push it towards a bent position, for the sliding of said stairlift.

According to a particular embodiment of the invention, said synchronizing mechanism comprises means for driving the synchronized displacement between said at least one first foot and said at least one second foot, at least when said at least one second foot is not contacting said at least one bearing surface, or it is in said first angular position, and for precluding the synchronized displacement between said at least one first foot and said at least one second foot, at least when said at least one second foot is in said second angular position and is^: contacting said at least one bearing surface, or when is contacting the rise of the last step of said stairs.

In particular, according to such embodiment, said driving and precluding means comprise at least one connecting rod rotatably constrained to said frame and synchronized to said at least one first foot, and at least one bar for connecting, directly or indirectly, said at least one connecting rod to said at least one second foot; said at least one connecting rod being constrained to said at least one connecting bar so that, at least when said at least one second foot is not contacting said at least one bearing surface, said at least one first connecting rod drives the movement of said at least one connecting bar between said first position and said second position and so that, at least when said at least one second foot is in said second position and contacting said at least one bearing surface or when contacting the rise of said upper step of said stairs, said at least one connecting bar slides with respect to said at least one connecting rod for the displacement of said at least one second foot in said bent position. Advantageously, said at least one connecting bar comprises at least one slot inside which said at least one connecting rod is constrained to slide, directly or indirectly, at least when said at least one second foot is contacting said at least one bearing surface and is in said second angular position, or when contacting the rise of said upper step of said stairs. Therefore, this allows to release said at least one first foot from said at least one second foot, when the second foot is in its second angular position contacting a bearing surface of the kind of the lower surface of the stairs, and consequently to aid the displacement of said at least one second foot in its bent position. This allows to greatly reduce the size of the raising, or lowering, unit.

According to a particular aspect of the invention, however it has to be mentioned that the objects of the invention are also achieved by a stairlift comprising a frame provided with at least one unit for raising, or lowering, said stairlift along the stairs having a plurality of bearing surfaces and at least one couple of wheels for the sliding of said stairlift, said at least one unit comprising at least one first foot movably constrained to

1

said frame, directly or indirectly, in order to raise, or lower, said stairlift along said stairs, at least one second foot movably constrained, directly or indirectly, to said frame, and at least one mechanism for synchronizing the displacement of said at least one second foot with respect to said at least one first foot during at least part of the raising, or lowering, of said stairlift along said stairs, said at least one second foot varying its own angular position with respect to at least one bearing surface of said plurality of bearing surfaces of said stairs and, depending on the direction of the force each second foot is subject to, at least when contacting a bearing surface of said stairs or the rise of a step of said stairs, being subjected to a moment adapted either to block it in position, in order to support said stairlift at least when said at least one first foot is not contacting at least one of the bearing surfaces of said stairs, or to push it towards a bent position, for the sliding of said stairlift.

BRIEF DESCRIPTION OF THE FIGURES

These and other aspects of the present invention will be more evident to the field technician from the following description of a preferred embodiment of the present invention, provided by way of example and not of limitation, referring to the attached figures, in which:

figures 1 - 7 show a side view of the stairlift according to the invention during the lowering (or raising) of the stairlift along the stairs;

figures 8-10 show a side view of the stairlift according to the invention during the lowering or raising of the stairlift in proximity of the lower surface of the stairs; figure 1 1 is a perspective view of the stairlift according to the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE PRESENT INVENTION

Referring particularly to such figures, with numeral 1 a stairlift according to the invention is shown.

In particular, as it is visible in the enclosed figures, the stairlift 1 comprises a frame 2 provided with one unit 3 for raising, or lowering, the stairlift along the stairs 100 and with two couples of wheels 30, 31 (in figures 1 to 10 only one wheel per couple is visible) for the sliding of said stairlift along a lower 100b, or upper 100a, surface of the stairs 100. The raising, or lowering unit 3, comprises two first feet 4 (in figures 1 to 10 only one first foot is visible) placed at the two sides 2a, 2b of the frame 2, movably and indirectly constrained to the frame 2 in order to raise, or lower, the stairlift 1 along the stairs 100 consisting, in the exemplary case shown in the enclosed figures, of three steps 101 , 102 and 103 and four bearing surfaces or landings 100a, 102a, 103a and 100b. It should be noted that the upper 100a and lower 100b surfaces are, respectively, the upper and lower landing of the stairs 100 along which the stairlift 1 can slide, whereas the landings 102a and 103 a are those of the steps 102 and 103. Obviously, the stairlift 1 according to the invention can also work on stairs of different shape, for example spiral stairs or having a higher, or lower number of steps and therefore a different number of bearing surfaces, or landings.

Advantageously, each first foot 4 is shaped so that to be contemporaneously in contact with two bearing surfaces, such as the surfaces 100a and 102a, or 102a and 103a, or 103a and 100b placed at different heights, during part of the raising, or lowering of the stairlift 1 along the stairs 100. In the enclosed figures, such two bearing surfaces are, respectively, the upper landing 100a of the stairs 100 and the landing 102a of the step 102 (as shown in figures 3 to 7), or the lower landing 100b of the stairs 100 and the landing 103a of the step 103 (as shown in figures 8 to 10). For simplicity, the case in which such two bearing surfaces are, respectively, the landing 102a of the step 102 and the landing 103a of the step 103, is not shown, but such a situation is however similar to that shown in figures 3 to 10.

Such a shape of the first foot 4 allows to lead the stairlift 1 in a safety condition to face stairs, both in raising and lowering. In fact, during the raising or lowering of the stairlift 1, that is, during the air phase of the stairlift, the two first feet 4, by leaning against two different bearing surfaces and having a different height, thus allow to assure a higher safety to the user, by the way without any operator being obliged to keep in balance the stairlift 1 during such an operation.

Furthermore, each first foot 4, precisely as a result of the L-shape thereof, has two free ends 4a, 4b to which the respective cylindrical abutment elements 61 are linked. Still according to the embodiment described in the enclosed figures, the raising or lowering unit 2 comprises, for each first foot 4, a first crank 6 hinged in a first point 6a to the frame 2, a second crank 7 hinged in a second point 7a to the frame 2, wherein each first foot 4 is rotatably constrained to the first crank 6 and to the second crank 7 at the hinging points 4c and 4d. In such a way the frame 2, first crank 6, second crank 7 and first foot 4, define a real four-bar linkage at each side 2a, 2b of the frame 2. Still according to the embodiment herein described, the stairlift 1 comprises an electric motor (herein not visible) fixed to the frame 2 and with a drive shaft placed at the hinging point 7a of the second crank 7; each second crank 7 is thus rotated by the electric motor and, in turn, rotate the respective first crank 6 and roto-translate the respective first foot 4 rotatably constrained to the two cranks 6 and 7. Such a motor can rotate both clockwise and anti-clockwise, depending whether the raising or lowering of the stairlift 1 along the stairs 100 has to be carried out. It should be mentioned that, according to the known art, the first crank 6 and second crank 7 are linked to each other by a chain so that the way of rotation of one crank is identical to that one of the other crank and, thus, avoiding that the two cranks 6 and 7 could jam the operation of the four-bar linkage by rotating in opposite directions.

According to the solution herein depicted, the raising, or lowering unit 2 further comprises two second feet 8 each arranged at a side 2a, 2b of the frame 2 and in a front position with respect to the first feet 4. Each second foot 8 is indirectly constrained to frame 2. Furthermore, the raising or lowering unit 2 comprises a mechanism 9 for the synchronized displacement of the two first feet 4 and two second feet 8. Therefore, practically, such a synchronizing mechanism 9 allows to move in a synchronized way the two second feet 8 following the movement of the two first feet 4 driven, in turn, by the second crank 7 forced to rotate by the above mentioned electric motor.

During the roto-translation of the two first feet 4, each second foot 8 varies its own angular position with respect to the bearing surfaces 100a, 102a, 103a, 100b of the stairs 100 between a first angular position PI and a second angular position P2 so that: - if the second foot 8 comes in contact with a bearing surface in said first angular position PI , such a second foot 8 is subject to a moment that blocks it in said first angular position, in order to support the stairlift 1 at least when the two first feet 4 are not contacting two bearing surfaces placed at different heights; - when the second foot 8 comes in contact with a bearing surface in said second angular position P2, such a second foot is subject to a moment adapted to push it towards a bent position P3, not to hinder the sliding of the stairlift 1 (see figures 8-10). In the same way, when each of the two second feet 8 comes in contact with the rise 101b of the last step 101 of the stairs 100, also in said first position PI , for example when performing a backward movement, is however subject to a moment that brings it to a bent position P3 not to hinder the sliding of the stairlift on the upper surface 100a of the stairs 100.

Practically, generalizing we can say that, depending on the direction of the force each second foot 4 (and therefore on the direction of the moment generated) is subject to, when contacting a bearing surface of the stairs or the rise of a step, each second foot 4 remains still to stop in position the stairlift 1 and thus to allow the first foot 4 to reposition on two bearing surfaces at distinct and different heights for the next raising, or lowering step of the stairlift 1, or it is pushed by the same bearing surface or by rise of the step towards a bent position P3, that is, of non-interference for the sliding of the stairlift along a generic plane.

It is noted that, thanks to such a solution, the condition wherein each second foot 8 comes in contact with a bearing surface of the stairs 100 in the angular position P 1 , is achieved when the two first feet 4 are in the air phase, that is not contacting any bearing surface. In the stairlift of the known art, such as for example described in ITPG2010A000034, in such a situation it is absolutely required the presence of an operator keeping in balance the stairlift 1 until the first feet 4 are touching a bearing surface for the next raising or lowering of the stairlift 1.

Furthermore, it has to be added that the free end 8a of each second foot 8 comprises an idle wheel 60.

Figure 1 shows that each second foot 8, leaving from the upper surface 100a of the stairs 100, has reached the contact with the bearing plane 102a of the step 102 in the angular position P 1 and, therefore, as shown in the following figures 2 and 3, it remains stopped in such a position to allow the two first feet 4 to bring back in such a position to contact at the same time two bearing surfaces, such as the surfaces 100a and 102a placed at different heights (as visible in figures 2 and 3).

Subsequently, in figures 4, 5, 6 and 7 different steps are shown wherein the two first feet 4 support the stairlift 1 during its displacement from the bearing surface 100a of the step 101 to the bearing surface 102a of the step 102. During such a step, the two second feet 8 are moved towards the following lower step 103, thereby reaching the bearing surface 103a in the first position PI . Following to the position reached and shown in figure 7, the two second feet 8 are in position identical to that one illustrated in figure 1. It has to be, noted that, during such a stage and before touching the bearing surface 103a, the two second feet 8 are also employed as anti-rollover elements as they are always facing the bearing surface 103a of the following step 103.

It should also be noted that, in case the stairlift 1 was at the last step 103 of the stairs 100 (figure 8), the two second feet 8, instead of meeting the bearing surface 103a in the angular position PI , meet the lower surface 100b of the stairs 100 in the angular position P2, since the latter is mostly extending with respect to the surface 103a of the step 103, and therefore they are subjected to a moment adapted to push them towards a bent position P3 (see figures 9 and 10), for the sliding of the stairlift 1.

In case of raising of the stairlift 1 from the last upper step 101 to the upper surface 100a of the stairs 100, each second foot 8, while being in the position P 1 when moving backward, meets and touches the rise 101b of the step 101 and is, hence, subject to a moment pushing it towards the bent position P3.

With the purpose of improving the stability of the stairlift 1 , the synchronizing mechanism 9 is further configured so that, at least when each second foot 8 is contacting a bearing surface 102a or 103a and is in said first angular position PI, a couple of sliding wheels 30, that one backward with respect to the stairlift 1 , is contacting a bearing surface 100a or 102a placed at a height, in the case in point upper, different from that each second foot 8 is in contact with. This is only visible in figures 1 and 2, but the situation happens for all of the remaining steps 102 and 103 of the stairs 100 with a considerable increase in stability of the stairlift 1.

As visible in figures, each second foot 8 is rotatably constrained to the frame 2 and, at least when is not contacting any bearing surface, it is driven by the first foot 4 and, through the synchronizing means 9, is urged to reciprocating rotatory motion between the first angular position PI and the second angular position P2, and vice versa.

Furthermore, between said first angular position PI and said second angular position P2, the two second feet 8 pass through a vertical position v (shown by a dashed line in figures 2, 8 and 9). In such figures it has also been depicted the angle β with respect to which the second foot 2 is rotated, still calculated taking into account the fact that the angular position of the second foot 8 is evaluated with reference to the straight line r^' connecting the hinging point 8b of each second foot 8 with the frame 2, and the hinging point of the idle wheel 60 placed at the end 8a of each second foot 8.

Still according to the embodiment illustrated in the enclosed figures, the synchronizing mechanism 9 comprises means 50 for driving the synchronized displacement between the two first feet 4 and the two second feet 8, at least when the two second feet 8 are not contacting any bearing surface or they are in said first angular position P 1 , and for precluding the synchronized displacement between the two first feet 4 and the two second feet 8, at least when the two second feet 8 reach a bearing surface from all the bearing surfaces 100a, 102a, 103a and 100b of the stairs 100, in the second angular position P2. In the specific case, at the lower surface 100b of the stairs 100 only. There is also the preclusion of the synchronization when the second foot 8 comes in contact, at the last upper step 101 , with the rise 101b of such a last step.

In detail, the driving and precluding means 50 comprise, for each first 4 and second foot 8, a connecting rod 10 rotatably constrained to frame 2 and synchronized to the first two feet 4, and a bar 1 1 for connecting each connecting rod 10 with the respective second foot 8. Each connecting rod 10 is constrained to the respective connecting bar 1 1 so that the connecting rod 10 drives the movement of the connecting bar 1 1 for the displacement of the second foot 8 between said angular position P 1 and second angular position P2 at least when the second foot 8, to which the bar 1 1 is linked through the projection 15 integral with the same second foot 8, is not contacting any bearing surface, and so that on the contrary the connecting rod 10 slides with respect to the connecting bar 1 1 for the displacement of the second foot in the bent position P3, at least when each second foot 8 is in the second position P2 and contacting a bearing surface (see figures 8 to 10). This is also accomplished when the second foot 8 comes in contact with the rise 101b of such last upper step 101 of the stairs 100.

Specifically, each connecting bar 1 1 comprises a slot 12 inside which the connecting rod 10 is constrained to slide by means of a pin (not visible in figure) when the respective second foot 8, to which the connecting bar 1 1 is linked, is contacting a bearing surface 100b and is in the second angular position P2 (still see figures 8 to 10). In fact in such a second position P2, wherein the straight line r, integral with the second foot 8, is in a forward position with respect to the vertical v, i.e. farther from the step, the second foot 8 is subject to a moment urging it to rotate in such a way that the connecting bar 1 1 slides with respect to connecting rod 10, thus in some sense precluding the synchronized connection between the first foot 4 and the second foot 8. The translation of the connecting rod along the slot 12 of the connecting bar 1 1 also occurs when each second foot 8 comes in contact with the rise 101b of the last upper step 101 of the stairs 100, since the rise 101b produces a moment on each second foot 8 involving the displacement thereof towards the bent position P3 (such a case is not visible in the enclosed figures, but similar to what depicted in figure 10).

Instead, in the case where the second foot 8 comes in contact with a bearing surface in the first angular position PI, wherein the straight line r, integral with the second foot 8, is set back with respect to the vertical v, i.e. closer to the step, then such a second foot 8 is subject to a moment balanced by a stop element (herein not visible) integral to the frame and able to hinder the rotation of the second foot 8 in the way opposite to which it reaches the bent position P3.

Still according to the embodiment herein described, said synchronizing mechanism 9 comprises, per each first foot 4, a first driven pulley 80 rotated by an arm 95 provided with a first hinging point 95a placed on the frame 2 and coaxial to the hinging point 6a of the first crank 6, and a second hinging point 95b placed on the first foot 4. Also such a second hinging point 95b is coaxial to that one 4c of the first crank 6, but such an arm 95 lies at the side of the first foot 4 opposite to that on which said first crank 6 lies. The synchronizing mechanism 9 further comprises a second pulley 81 rotatably constrained to the frame 2 in its hinging point 81 a, and a belt 82 (or a chain) for the transmission of the motion between the first pulley 80 and the second pulley 81. Furthermore, each connecting rod 10 is integrally constrained to the respective second pulley 82 so that to be rotated by the latter in a synchronized way.

Since the first pulley 80 is integral to the arm 95 and shares also the hinging point 95a, it follows that each connecting rod 10 is rotated by the respective second pulley 81 , which is rotated by the first pulley 80 following the synchronized rotation of the arm 95 with the first foot 4.

Still according to the embodiment herein described, said synchronizing means further comprise means 90 to push the two second feet 8 to the first angular position PI , at least when the two second feet 8 are not contacting any bearing surface. In particular, said pushing means 90 comprise two compression springs 91 (in figure only one compression spring is visible) each rotatably constrained, at one end 91 a, to a second foot 8 and, at a second end 91b, to the frame 2.

Claims

1. Stairlift (1) comprising a frame (2) provided with at least one unit (3) for raising, or lowering, said stairlift along the stairs (100) having a plurality of bearing surfaces (100a, 102a, 103a, 100b) and at least one couple of wheels for the sliding of said stairlift, said at least one unit (3) comprising at least one first foot (4) movably constrained to said frame (2), directly or indirectly, in order to raise, or lower, said stairlift (1 ) along said stairs (100), characterized in that said at least one first foot (4) is shaped so that to be contemporaneously in contact with at least two bearing surfaces (100a, 102a; 102a; 103a; 103a, 100b) of said plurality of bearing surfaces (100a, 102a, 103a, 100b) placed at different heights, during at least part of the raising, or lowering, of said stairlift (1) along said stairs (100).

2. Stairlift (1 ) according to claim 1 , characterized in that said at least one foot (4) is L-shaped.

3. Stairlift (1) according to claim 1 or 2, characterized in that said at least one raising, or lowering, unit (2) comprises at least one first crank (6) hinged in a first point

(6a) to said frame (2), at least one second crank (7) hinged in a second point (7b) to said frame (2), wherein said at least on first foot (4) is rotatably constrained to said at least one first crank (6) and said at least one second crank (7).

4. Stairlift (1) according to one or more of the preceding claims, characterized in that said at least one raising lowering unit (2) further comprises at least one second foot (8) movably constrained, directly or indirectly, to said frame, and at least one mechanism (9) for synchronizing the displacement of said at least one second foot (8) with respect to said at least one first foot (4) during at least part of the raising, or lowering, of said stairlift along said stairs, said at least one second foot (8) varying its own angular position with respect to at least one bearing surface of said plurality of bearing surfaces (100a; 102a; 103a, 100b) of said stairs (100) and, depending on the direction of the force each second foot (8) is subject to, at least when contacting a bearing surface of said stairs or the rise, of a step of said stairs, being subjected to a moment adapted either to block it in position, in order to support said stairlift (1 ) at least when said at least one first foot (4) is not contacting said at least two bearing surfaces placed at different heights, or to push it towards a bent position (P3), for the sliding of said stairlift (1).

5. Stairlift (1) according to one of more of the preceding claims, characterized in that said at least one second foot (8) varies its own angular position with respect to at least one bearing surface of said plurality of bearing surfaces of said stairs between a first angular position (PI) and a second angular position (P2) so that:

- at least when contacting said at least one bearing surface (102a; 103a), in said at least one first angular position (PI), it is subjected to a moment adapted to block it in position, in order to support said stairlift (1) at least when said at least one first foot (4) is not contacting said at least two bearing surfaces placed at different heights; and

- at least when contacting said at least one bearing surface, in said second angular position (P2), it is subjected to a moment adapted to push it towards a bent position (P3), for the sliding of said stairlift (1);

- at least when contacting the rise of the last upper step (101 ) of said stairs (100), in said at least one first angular position PI , it is subjected to a moment adapted to push it towards a bent position (P3), for the sliding of said stairlift (1).

6. Stairlift (1 ) according to claim 4 or 5 characterized in that, at least when said at least one second foot (8) is contacting said at least one bearing surface (102a; 103a) and subjected to a moment adapted to block it in a stable position, said at least one couple of sliding wheels (30; 31) is contacting an additional bearing surface (100a; 102a) placed at a height different from said bearing surface for said at least one second foot (8).

7. Stairlift ( 1 ) according to one or more of claims 4 to 6, characterized in that said at least one second foot (8) is rotatably constrained with respect to said frame (2) and, at least when it is not contacting said at least one bearing surface of said plurality of bearing surfaces, it is driven to perform a reciprocating rotary motion between said first angular position (PI) and said second angular position (P2), and vice versa.

8. Stairlift (1) according to claim 7 characterized in that, between said first angular position (PI) and said second angular position (P2), said at least one second foot (8) passes through a vertical position.

9. Stairlift according to one or more of claims 4 to 8, characterized in that said at least one second foot (8) is arranged in a front position relative to at least one first foot.

10. Stairlift according to one or more of claims 4 to 9, characterized in that said synchronizing mechanism (9) comprises means (50) for driving the synchronized displacement between said at least one first foot (4) and said at least one second foot (8), at least when said at least one second foot is not contacting said at least one bearing surface, or it is in said first angular position, and for precluding the synchronized displacement between said at least one first foot and said at least one second foot, at least when said at least one second foot is in said second angular position and is contacting said at least one bearing surface.

1 1. Stairlift according to claim 10, characterized in that said driving and precluding means comprise at least one connecting rod (10) rotatably constrained to said frame and synchronized to said at least one first foot, and at least one bar (1 1) for connecting, directly or indirectly, said at least one connecting rod to said at least one second foot, said at least one connecting rod being constrained to said at least one connecting bar ( 1 1 ) so that, at least when said at least one second foot (8) is not contacting said at least one bearing surface, said at least one first connecting rod drives the movement of said at least one connecting bar for the displacement of said at least one second foot between said first position (PI) and said second position (P2) and so that, at least when said at least one second foot is in said second position and contacting said at least one bearing surface, said at least one connecting bar (1 1) slides with respect to said at least one connecting rod for the displacement of said at least one second foot in said bent position (P3).

12. Stairlift according to claim 1 1 , characterized in that said at least one connecting bar (1 1) comprises at least one slot (12) inside which said at least one connecting rod is constrained to slide, directly or indirectly, at least when said at least one second foot is contacting said at least one bearing surface and is in said second angular position.

13. Stairlift (1) according to one or more of the preceding claims, characterized in that it comprises at least one electric, or hydraulic, motor, and in that said at least one first crank, or said at least one second crank, or said at least one first foot, is driven by said at least one motor.

14. Stairlift (1) according to claim 13, characterized in that said synchronizing mechanism comprises at least one first pulley (80) directly or indirectly driven by said motor, at least one second pulley (81 ) rotatably constrained to said frame (2), and at least one belt (82) for the transmission of the motion between said first pulley and said second pulley, said at least one connecting rod being integrally constrained to said at least one second pulley.

15. Stairlift according to one or more of claims 4 to 14, characterized in that-said synchronizing means further comprise pushing means (90) for pushing said at least one second foot (8) to said first angular position (PI), at least when said at least one second foot is not contacting said at least one bearing surface of said plurality of bearing surfaces.

16. Stairlift according to claim 15, characterized in that said pushing means comprise at least one compression spring (91) that is rotatably constrained, at one end (91 a), to said at least one second foot (8) and, at a second end (91b), to said frame (2).