Lifting bridge, in particular for motor vehicle

Abstract

The invention relates to an elevator, in particular for a motor vehicle, comprising at least one lane (2); two legs (4, 4 ') hinged to the at least one lane (2) and each leg (4, 4') consisting of a single arm; at least one actuator (18, 18 ') associated with each leg (4, 4') and configured to vary the inclination of each leg (4, 4 ') with respect to the horizontal so as to raise and lower the at least one lane (2); and a synchronous control unit of all the actuators (18, 18 '); characterized in that: the two legs (4, 4 ') hinged to the at least one lane (2) are arranged symmetrically with respect to the transverse median plane of the elevator; -the lower end of each leg (4, 4 ') is hinged to the base (8) in connection with a fixed transverse shaft (10) to be anchored to the floor; -the upper end of each leg (4, 4 ') is articulated to the respective lane (2) by connecting to a transverse axis (12, 12') which is connected to a trolley (14) sliding along the lane itself; the upper end of each supporting leg (4, 4 ') is hinged to two sliding frames (14); the two carriages (14) are connected to each other by a pair of flexible traction elements (22, 22 ', 22' '), each traction element being connected to the two carriages (14) at the ends and each traction element being returned by a respective transmission member (24, 24') idling mounted on the lane (2), all of which generally define a substantially closed ring-shaped structure such that, as the inclination of the legs (4, 4 ') varies, the traction elements (22, 22', 22 '') are driven by the respective transmission member (24, 24 '). Each lane (2) is translated longitudinally towards the legs that are at this time slightly inclined with respect to the horizontal plane.

Description

[0001] The invention relates to a lift for a motor vehicle.

[0002] Lifts for motor vehicles are known, comprising a pair of carriageways and two articulated legs, on which the motor vehicle to be lifted is placed, above each carriageway and below a base, which may consist of a spar anchored or placed in the floor, or the base may consist of the same floor, suitably configured and reinforced so as to support the legs in an articulated manner.

[0003] Each leg may consist of a single rigid element or arm, articulated below to the base and below to the track; or may consist of several rigid elements or arms, articulated together and also articulated below to the base and below to the track.

[0004] The upward and downward movement of the two lanes is usually achieved by hydraulic actuators placed between the legs and the lanes, or between the legs and the base, or between the articulated arms forming each leg.

[0005] A hydraulic power unit connected to the actuator directs oil into the actuator and exhausts oil from the actuator, thereby causing synchronized upward and downward movement of the lane relative to the base.

[0006] There are various types of lifts: for example, a so-called "parallelogram" lift is described in US 4848732. It comprises two base beams anchored or placed on the floor, two lifting mechanisms relative to the base beams and two or more pairs of legs, each pair of legs consisting of a single element articulated above to the base beams and below to the corresponding carriageway.

[0007] In these lifts, the lifting of the lanes relative to the beam is achieved by placing an actuator between two homologous legs and the corresponding lanes. As the actuators lengthen and shorten as hydraulic fluid is introduced into or discharged from them, the angle formed between each leg and the lane in which each actuator is placed changes, which determines the deformation of the parallelogram formed by each beam, the corresponding lane and the two legs articulated to both, and thus determines a substantially translational movement of the lanes with a vertical component.

[0008] In this type of lift, the trend curve representing the pressure of the hydraulic fluid in the actuator as a function of the lift travel of the carriage is downward, in the sense that the greater the height reached by the carriage, the lower the pressure in the hydraulic system that keeps it lifted, which is advantageous because the pressure on the actuator and on the mechanical safety locking device of the lifted lift is lower than the pressure required to raise the lift.

[0009] This type of lift has been widely promoted due to its simple structure and operational reliability, but it also highlights some disadvantages, in particular:

[0010] - during the raising of the carriageway, there is a horizontal component to its movement, with the attendant consequence that the overall dimensions of the raised lift are significantly greater than those of the lowered lift, thus requiring a larger space for its installation than would be required for a lift in which the carriageway moves in a substantially vertical motion;

[0011] - the space occupied by the beams in the ground, which prevents the operator from passing freely under the raised lift; this inconvenience can be overcome by eliminating the side members and hinge the legs directly on the floor, however, in this case, it is necessary to prepare for this installation, for example by embedding concrete beams in the floor for the structural connection of the legs;

[0012] - Due to the integral nature of the outriggers, the maximum height that the lane can reach is limited and cannot be made excessively long without negative structural and operational impacts on the lift;

[0013] -When each lifting jack is placed between the outrigger and the track, the track actually has four or more restraint points, so statically indeterminate behavior occurs.

[0014] Another known type of lift, such as that described in US 8286944, is characterized in that each leg is formed by two arms of substantially equal length, articulated at one end to each other and at the other end to the respective base and track. In these known lifts, the track is moved in a substantially vertical motion, and the hydraulic actuator for raising and lowering the track is placed between the two arms of each leg, which also require that these two arms be assisted by other articulated arms, having the function of stabilizing the leg-track complex and providing further support for the track, which is in fact supported at four points, namely two points for each leg.

[0015] In these known lifts, the positioning of the base to which the legs are articulated requires high precision in order to allow full raising and lowering of the lift.

[0016] Furthermore, the support of each track at four points implies an indeterminate constraint which, in the event of deformations of the track or simply in the event that the track reaches different heights due to load imbalances or imbalances generated by the actuator synchronization system, gives rise to indeterminate forces which involve forces related to the constraints and deformations of the lift structure and which can only be partially reduced by the elastic compensation system of the legs.

[0017] Another disadvantage is that the trend curve representing the pressure of the hydraulic fluid supplied to the actuator as a function of the lift travel of the carriageway first decreases until it reaches a minimum value and then starts to increase again until it reaches almost the high starting value when the lift is fully raised. This means that the pressure on the actuator and the mechanical safety locking device of the raised lift is greatest when the lift is raised, i.e. in active working order.

[0018] Other disadvantages of this known type of lift are the high complexity of manufacture, associated with the large number of components which must be connected to one another and which inevitably involve plays and inaccuracies in their mutual movement.

[0019] Also known from EP 3995437 is a lift for motor vehicles comprising a pair of tracks, each supported by a pair of legs placed symmetrically with respect to a transverse centre plane of the lift. Each leg comprises a main rigid arm, articulated at the bottom to a base by connection with a first fixed transverse axis, and articulated at the top to the track by connection with a second transverse axis, which slides longitudinally along the track. Each leg also comprises an auxiliary arm, articulated at the top to the track by connection with a third fixed transverse axis, and articulated to the main arm by connection with a fourth fixed transverse axis, at the same distance from the second and third transverse axes. Each actuator for raising the lift is placed between the third transverse axis and a fifth transverse axis different from the fourth axis, and is fixed relative to the main arm.

[0020] The shortcoming of this well-known lifter is the hyperstatic connection of lifter track and outrigger and the large size of outrigger along its length.In addition, these lifters also have other shortcomings related to the described lifter according to US 8286944.

[0021] Finally, other known lifts also have legs consisting of two or more elements connected together by an articulation system involving a non-vertical movement of the track and generally with the legs arranged asymmetrically with respect to the track relative to the transverse median plane of each track; and this asymmetry in turn determines an asymmetrical behavior of the track relative to the load.

[0022] The present invention aims at creating a lift for motor vehicles which substantially eliminates all the drawbacks discernible in lifts of known type, while retaining the associated advantageous aspects.

[0023] More specifically, the object of the invention is to create a lift in which the movement of the carriageway occurs in a substantially vertical direction.

[0024] Another object of the invention is to create a lift in which each leg consists of a single element, articulated below with the base and above with the carriageway of the lift, thus having limited manufacturing complexity.

[0025] Another object of the invention is to create a lift capable of reaching a maximum height of the driveway equal to that achievable with current lifts using legs formed by a single arm but having a greater overall length.

[0026] Another object of the invention is to create a lift capable of reaching a maximum height of the driveway equal to that achieved by current lifts using legs formed by several articulated arms.

[0027] Another object of the present invention is to provide an elevator in which the support of the rails by the legs is of a balanced type, eliminating stresses associated with binding and deformation of the elevator structure.

[0028] Another object of the invention is to create a lift that does not hinder the free passage of the operator underneath the raised lift.

[0029] Another object of the invention is to create an elevator that has a dissipative behavior in the event of a seismic event.

[0030] Another object of the present invention is to create a lift that reduces deformation and structural stresses on the carriageway when the lift is raised.

[0031] All these objects, and others which will ensue from the following description, are achieved according to the present invention, either jointly or individually, by a lift for motor vehicles as defined in claim 1.

[0032] The present invention is further illustrated below by some preferred practical embodiments, which are described with reference to the accompanying drawings for illustrative and non-limiting purposes only, in which:

[0033] Figure 1 schematically shows a perspective view of a lift in a raised state according to the invention;

[0034] Figure 2 Shown according to Figure 1 II-II of the enlarged vertical cross-section;

[0035] Figure 3 Shown with Figure 2 The same view, but in a lowered state;

[0036] Figure 4 is a perspective view of a longitudinal half of the lift without the upper carriageway in the first embodiment, in a state where the lift is raised;

[0037] Figure 5 The effect of the working principle of the lift according to the present invention is schematically shown;

[0038] Figure 6 Details showing the pulleys constrained to a single lane by cushioned supports;

[0039] Figure 7 Shown with Figure 4 The same view, i.e. a perspective view of the longitudinal half of the lift without the upper carriageway in a second embodiment, in the lifted state;

[0040] Figure 8 The third embodiment shows Figure 4 Same view;

[0041] Fig. 9 The fourth embodiment shows Figure 4 Same view;

[0042] Fig.10 The fifth embodiment shows Figure 4 Same view;

[0043] Fig.11 The sixth embodiment shows Figure 4 Same view;

[0044] Fig.12 The seventh embodiment shows Figure 4 Same view;

[0045] Fig.13 The eighth embodiment shows Figure 4 Same view;

[0046] Fig.14 A side view is shown in an eighth embodiment.

[0047] As can be seen in the figure, the lift according to the invention comprises two carriageways 2, intended to accommodate motor vehicles or, in any case, loads to be lifted, and two pairs of legs 4, 4', intended for the articulated support of the two carriageways. Each leg consists of a single element, configured and dimensioned according to the specific stresses arising from the project. Preferably, each leg 4, 4' is made of metal sheets of suitable shape and thickness, welded together so as to define a box-shaped element capable of effectively resisting the bending and torsional stresses typical of lifts, in particular when they are subjected to the stresses of eccentric loads which may occur when the lift is equipped with auxiliary crosspieces connecting the carriageways, bearing mainly on the inner edges of the carriageways. In fact, for this purpose, it may be advantageous to provide a structure having, for example, a protruding continuous longitudinal step 6 (see Figure 2 , Figure 3) of the profiled track 2, which is very useful for supporting those auxiliary crosspieces (not shown, as they are conventional) which are usually required to facilitate the operator's work on vehicles placed on the raised lift track.

[0048] Each leg 4, 4' is articulated below to a base 8, preferably anchored to the floor, and above to the corresponding track 2. However, while the lower articulation of each leg 4, 4' to the relative base 8 occurs at a fixed transverse axis 10, the upper articulation of each leg 4, 4' to the relative track 2 occurs at a position corresponding to a carriage 14 which, in this embodiment, comprises a rigid crosspiece 12, 12' fixed to the upper end of the leg itself and provided at its end with a block for sliding along the track 2, preferably in the longitudinal guides thus obtained.

[0049] An actuator 18 is connected to each base 8 by means of a connection with a fixed transverse axis 16 different from the axis 10, the actuator 18 being preferably of the hydraulic type, consisting of a jack whose rod is articulated to the corresponding leg 4, 4' by means of a connection with a transverse axis 20, preferably located approximately in the central area of ​​the leg itself. The two actuators 18 applied to the two legs 4, 4' are connected to a power supply and a control unit (not shown) and are synchronized with each other in their movements by means of a shunt or an electronic system, which are themselves conventional and will not be described further. However, it is conceivable that not one but two side-by-side actuators may be applied to the same leg 4, 4', their movements obviously being synchronized.

[0050] exist Figure 4 In the first embodiment shown, a metal cable 22, 22' is fixed at one end to each trolley 14 and at the other end to the other trolley 14. The two cables 22, 22' are returned through respective idle pulleys 24, 24' having horizontal axes connected to the track 2 at a position outside the two legs 4, 4', preferably to the respective side walls of the track itself.

[0051] In this way, the two metal cables 22, 22' and the two pulleys 14 to which they are fixed form a closed loop, which surrounds the two pulleys 24, 24' and establishes a further connection between the track 2 and the legs 4, 4', designed to control the sliding of the track relative to the legs when the legs themselves have different inclinations, which will be described in detail later.

[0052] In view of their function, the two steel cables 22, 22' can be replaced by chains or belts or other substantially inextensible flexible traction elements.

[0053] The shape and size of the legs 4, 4' and base 8 of the track 2 are preferably such that when each track 2 is in its lowest position, it actually rests on the floor, housing the base 6, legs 4, 4' and actuator 18 therein, so that Figure 2 and Figure 3 This can be seen in the comparison.

[0054] In this lowered state, the axis of articulation 10 of each leg 4, 4' at the respective base 8 is preferably at a higher level than the axis of articulation 16 of the respective actuator 18 at the base itself, and also higher than the axis of articulation 12, 12' of each leg 4, 4' to the respective track 2. Since, in practice, this last axis of articulation coincides with the axis of the crosspiece 12, 12', in this description the crosspiece 12, 12' of each trolley 14 and the axis of articulation of the leg 4, 4' to the track 2 are identified with the same reference numerals.

[0055] Furthermore, the articulation axis 20 of each actuator 18 connected to the relative leg 4 , 4 ′ is preferably always at a higher height than the articulation axis 16 of the actuator itself at the base 8 , when each lane is in the lowest position.

[0056] The operation of the lift according to the invention can be better understood if we first distinguish between the case where the lift loads the motor vehicle in a balanced manner and the case where the lift loads the motor vehicle in an unbalanced manner, for example the front of the motor vehicle is heavier than the rear.

[0057] In the ideal case of perfectly balanced loads and without tolerances in the synchronizing system of the lift's lifting actuators 18 , the track 2 moves in a perfectly vertical translational movement and remains perfectly centered in the longitudinal direction relative to the legs 4 , 4 ′ during lifting of the lift.

[0058] However, in real situations, the loads are almost always unbalanced and there are always unavoidable intervention tolerances in the synchronization system of the actuators 18. If, under these conditions, the track 2 is connected to the legs 4, 4' only by means of a connection with the trolley 14, then during the ascent and descent of the lift, the inevitably greater deformation of the most loaded leg and its different inclination relative to the other leg will cause each track 2 to slide uncontrolled relative to its leg 4, 4', within the limits of the system's degrees of freedom, in a direction consistent with the movement of the upper end of the leg 4 or leg 4', at which point greater friction will occur with the track 2, regardless of whether the load placed on this leg is large or small.

[0059] However, the presence of this further constraint between each track 2 and the corresponding leg 4, 4' by means of the cables 22, 22' and the pulleys 24, 24' means that if, for example due to load imbalance, one of the legs 4 or 4' of each track 2 is less inclined than the other leg, the longitudinal sliding of the track 2 is controlled in a sense that this sliding always occurs towards the leg 4 or 4' with the least inclination and its sliding amount is equal to half the difference in the travel along the track 2 of the sleepers 12, 12' to which the legs themselves are connected.

[0060] Figure 5 The operating principle of the lift being described according to the invention is schematically illustrated: from it it can be seen that, assuming that the legs 4 of the lift are, for example, more heavily loaded than the legs 4 ′ of the same track 2, the smaller inclination of this leg 4 relative to the horizontal plane leads to a smaller inclined sliding of each track 2 relative to the upper end of the leg 4, until the transverse center plane of the track itself returns to a position equidistant from the crosspieces 12, 12′.

[0061] In this way, a series of advantages can be obtained, with a relatively simple elevator structure and safe and reliable operation, which was not available with traditional elevators before.

[0062] One advantage is that the movement of each lane 2 of the elevator relative to its legs 4, 4' can be controlled according to a determined movement law as a function of the different inclinations of the legs relative to the horizontal.

[0063] Another advantage is that the support of each lane 4 , 4 ′ on the legs 2 occurs only at two points, thus constituting an isostatic restraint that excludes the generation of stresses associated with restraint and deformation of the structure.

[0064] Another advantage is that the arrangement of the legs 4, 4' relative to the track 2 means that as the lift rises the two supports of each track 2 on the two legs 4, 4' become closer together, which reduces the inevitable bending deformation of the track under load when the lift is raised.

[0065] Another advantage is that the trend curve representing the pressure of the hydraulic fluid in the actuator 18 as a function of the lifting stroke of the carriageway 2 is decreasing, with all the beneficial effects in terms of stress on the actuator 18 and the control means, the mechanical safety of the raised lift always existing.

[0066] Another advantage is that there are no obstructions for the operator underneath the raised lift.

[0067] Another advantage is that in case of a seismic event, the energy applied to the lift is partially dissipated by the friction generated in the relative movement between the track 2 and the legs 4, 4' due to the further substantially elastic connection between the cables 22, 22' and the pulleys 24, 24'.

[0068] Another advantage is that, when the lift is lowered, the legs 4, 4' are at a higher height at the articulation axis 10 at the respective base 8 than at the articulation axis 12 of the legs themselves at the track 2, which allows the use of the entire length of the legs 4, 4', so that legs of shorter length can be used, with the same overall dimensions of the lift being lowered and the same maximum height that can be reached from the track 2. In particular, with the lift according to the invention, it is possible to obtain a ratio between the vertical lifting travel of the track 2 and the length of the legs 4, 4' (measured with reference to the articulation axis 10 and the articulation axis 12) which is close to or even greater than 1, unlike conventional lifts in which this ratio is significantly less than 1, the length of the leg being considered as the sum of the lengths of the two arms that form it, whether the lift's legs consist of a single arm or the lift's legs consist of articulated arms.

[0069] It should be noted that, when the lift is raised, differences in the loads affecting the points of support of the track 2 on the legs 4, 4' are usually due to various reasons, such as, in particular, uneven distribution of weight in the motor vehicle raised, differences in the behavior of the safety devices, deviations in the hydraulic power supply, differences in the pressure on the various jacks and consequently in the elongation of the jacks, deviations in the power supply, which tend to modify the geometry of the lift and to arrange its two track 2 in a different way, contrary to the reaction of the motor vehicle placed on the track in a braking state, which tends to exist to prevent the relative movement between them according to the track axis.

[0070] If this tendency to change the geometry of the lift is kept below a certain level, related to the structural characteristics of the lift, it can be absorbed by the contact between the vehicle tires and the track, the deformability and clearance of the lift itself, and the elasticity of the cables 22, 22'. Since, in practice, this tendency may exceed the capacity of the deformability and clearance of the lift itself and the elasticity of the cables to absorb it, the invention envisages overcoming this tendency by mounting each pulley 24, 24' on a buffer support, more specifically on a pin 26, which in turn is mounted on a trolley 28, which is equipped with a rod 30 that slides axially in a bracket 32 ​​fixed to the track 2, so as to allow the trolley itself to move along the bracket 32. A pre-stressed spring 34 is placed between the carriage 28 and the bracket 32, which keeps the cables 22, 22' taut and is capable of yielding elastically if the cables 22, 22' are subjected to a traction greater than a predetermined value.

[0071] Figure 6 The buffer pulley 24 and its supporting carriage 28 are schematically shown in FIG.

[0072] exist Figure 7 , a second embodiment is schematically shown, which differs from the previous embodiment due to the presence of an additional pulley 36 or a similar deflection component, which is also idlingly mounted on the track 2 and has the function of deflecting the straight sections of the cables 22, 22', thereby changing their direction so that they are parallel to the track 2 in the tensioning section.

[0073] This second embodiment presents, on the one hand, a greater manufacturing complexity due to the need for these additional deflection pulleys 36, but on the other hand ensures a more precise control of the movement of the track 2 relative to the legs 4, 4', since the cable portions 22, 22' comprised between the deflection pulleys 36 and the trolley 14 are substantially parallel to the upper surface of the track 2. If you wish to have all the straight portions of the two cables 22, 22' parallel to the upper surface of the track, you can provide pairs of deflection pulleys 36, such as Figure 8 The third embodiment is shown.

[0074] exist Fig. 9 In the fourth embodiment shown, the raised lift is provided with a single cable 22″ closed in a loop, fixed at two points diametrically opposite to the trolley 14 and transmitted externally to the two legs 4, 4′ through pulleys 24, 24′ which, in addition to defining the distance between two straight sections of the cable 22″ corresponding to the width of the trolley 14, are placed at different heights so as not to interfere with the movement of the trolley itself. This can be achieved by placing two pairs of pulleys 24, 24′ in the two return areas of the cable 22″, located on inclined planes in the opposite direction to the upper plane of the track 2, and with dimensions that correctly define the distance between the two straight sections of the cable, and by placing two pairs of deflection pulleys 36 on each longitudinal side of the loop formed by the cable itself; or it can be achieved by using a pair of pulleys (not shown) with a diameter equal to the distance between these straight sections, which are arranged on opposite inclined planes in the two return areas of the cable 22″.

[0075] Fig.10 The fifth embodiment shown always involves the use of a single cable 2″ which is placed completely on one side of the roadway 2. For example, Fig. 9 and Fig.10As can be seen from the comparison of the embodiment, this embodiment allows reducing the number of deflection pulleys 24, 24', 36 and reducing the size of the cables 22" and the pulleys 24, 24' in the lane 2. In turn, this reduction in size allows each leg 4, 4' to be asymmetrical with respect to the longitudinal plane of the lane 2, which can reduce the torsional moment on the legs when using a lifting beam placed between the lanes.

[0076] In this fifth embodiment, it is preferred that the deflection pulley 36 and / or the deflection pulleys 24, 24' are mounted on the track 2 with their respective rotation axes not parallel to each other but slightly inclined in opposite directions so as to keep the two sections of the single cable 22" in the center area of ​​the track at a slight distance from each other and avoid unnecessary interference between them.

[0077] exist Fig.11 In the sixth embodiment shown, a pair of rods 38 are attached to the carriage 14 associated with each leg 4 , 4 ′, which are housed in corresponding longitudinal guide cavities obtained in the corresponding track 2 and extend towards the other leg 4 ′, 4 articulated thereto.

[0078] The other ends of the two rods 38 connected to each leg 4 , 4 ′ are also connected to a respective trolley 40 configured to slide along the central part of the track 2 , ie along the track section inside the trolley 14 .

[0079] Each trolley 40 is connected to one of two straight sections of a single metal cable 22″, which is closed in a loop around two identical pulleys 24, 24′ with vertical axes, which are mounted idling on the track 2, outside the two pulleys 40 but inside the two pulleys 14. In this way, the two pulleys 40 are connected to each other in a sense that forces them to move simultaneously in opposite directions along the track 2. Then, thanks to the connection between the pulley 40 and the pulley 14 through the rod 38, a controlled longitudinal movement of the track 2 is also achieved in this case, as the inclination of the legs 4′, 4 changes.

[0080] Obviously, the single cable 22 ″ can be replaced by two cables, which are connected to two pulleys 40 at both ends after returning through the two pulleys 24, 24'.

[0081] This sixth embodiment has the important advantage of occupying limited space beneath the track 2 and ensuring easy access for maintenance of the cables and pulleys.

[0082] In all the embodiments now described, the distance between the lower ends of the two legs 4 , 4 ′ is always smaller than the distance between the upper ends of the legs themselves.

[0083] Fig.12The seventh embodiment shown is always based on the same principle, i.e. the carriage 2 is placed on two legs 4, 4' at two points (equilibrium support) and each carriage 2 has a controlled longitudinal sliding movement relative to the upper end of the legs 4, 4', but differs from the previous embodiments in that the distance between the lower ends of the two legs 4, 4' is always greater than the distance between the upper ends of the legs themselves. In this case, however, the controlled longitudinal sliding of the carriage 2 always takes place towards the leg 4 or 4' which is most inclined relative to the horizontal.

[0084] The seventh embodiment has the further advantage over the previous embodiments that two shorter cables 22, 22' (or a single cable 22" closed in a loop) are required, so that the elongation under stress is smaller, but it also has the disadvantage that the load on the lane 2 is greater when the lift is raised, and considering the longer length of the cantilever portion of the lane, a greater hydraulic fluid pressure is required in the initial stage of lifting the lift.

[0085] even though Fig.12 A seventh embodiment is shown, which uses a Fig.11 The sixth embodiment shown relates to the same connection method described above, but it is understood that all other previously described embodiments may also bring the upper ends of the legs 4, 4' closer together than the lower ends, obviously with all the advantages and disadvantages of these different embodiments.

[0086] Fig.13 The eighth embodiment shown differs from all the previous embodiments described previously in that an actuator 18' is inserted between the legs 4, 4' and the trolley 14 sliding along the track 2. In this case, the trolley 14, to which the upper ends of the legs 4, 4' are articulated, has a greater longitudinal development than the trolley 14 of the previous embodiments, since the upper end of the actuator 18' must also be articulated to the trolley by connection with an articulation axis 42 different from the axis 12, 12' to which the legs 4, 4' are articulated with the trolley itself.

[0087] In order to obtain coordination in the movement of the carriages, the connection between the two carriages 14' can be achieved using any of the methods described in the previous embodiments, and there is no need to describe them again. In addition, even if this embodiment stipulates that the upper ends of the two legs 4, 4' are closer to each other than their lower ends, the present invention also includes an embodiment in which the actuator 18' is arranged above, that is, between the lane 2 and the legs 4, 4' but with the lower ends closer than the rear ends.

[0088] All embodiments of the actuator 18' arranged as described above, in addition to all the advantages that the other embodiments also have compared with the prior art, have another advantage, namely that all the components of the elevator, which may be considered critical for different reasons, namely the actuators, mechanical safety devices, electrical and electronic control devices usually associated with the actuators, and the connections between these components and the power supply and control unit, are located in the upper part of the elevator, which means that during the use of the elevator, the elevator is kept at a distance from the floor and is therefore better protected from the dirt (contaminated materials, washing liquids, etc.) that is usually mainly present on or near the floor.

[0089] In another embodiment not shown in the drawings, the lift according to the invention comprises a single carriageway, two legs associated with the single carriageway and a plurality of crosspieces applied to the carriageway and configured to support and lift motor vehicles. Since in this single-lane lift, on the one hand, the legs are connected to one another in one of the shapes already described, and on the other hand, the configuration of the single carriageway and the crosspieces applied to the single carriageway are conventional per se, a more in-depth description of this embodiment would seem superfluous.

Claims

1. A lift, in particular for motor vehicles, comprising at least one carriageway (2); two legs (4, 4') articulated to said at least one carriageway (2), each leg (4, 4') consisting of a single arm; at least one actuator (18, 18') associated with each leg (4, 4') and configured to vary the inclination of each leg (4, 4') relative to the horizontal plane, thereby raising and lowering said at least one carriageway (2); and a control unit for synchronizing all the actuators (18, 18'); characterized in that: - the two legs (4, 4') articulated to the at least one track (2) are arranged symmetrically with respect to a transverse median plane of the lift, - the lower end of each leg (4, 4') is hinged to the base (8) by connection with a fixed transverse axis (10) so as to be anchored to the floor, - the upper end of each leg (4, 4') is articulated to the corresponding track (2) by connection with a transverse axis (12, 12') connected to a trolley (14) sliding along the track itself, - The upper end of each leg (4, 4') is hinged to two carriages (14), the two carriages (14) are connected to each other by a pair of flexible traction elements (22, 22', 22"), the ends of each traction element are connected to the two carriages (14), and each traction element is returned by a corresponding transmission member (24, 24') mounted idling on the track (2), all of which generally define a substantially closed annular structure, so that as the inclination of the legs (4, 4') changes, each track (2) moves longitudinally in translation towards the leg that is less inclined relative to the horizontal plane at this time.

2. The lift according to claim 1, characterized in that: In the lowered elevator configuration, the articulation axis (10) of each leg (4, 4') at the respective base (8) is placed at a higher level than the articulation axis (12, 12') of the leg itself connected to the respective carriage (14).

3. The lift according to claim 1 and / or 2, characterized in that: The at least one actuator (18) is placed between each leg (4, 4') and the corresponding base (8).

4. The lift according to claim 1 and / or 2, characterized in that: The at least one actuator (18') is placed between each leg (4, 4') and the trolley (14) sliding along the corresponding track (2).

5. The lift according to claim 3, characterized in that: In the lowered lift configuration, the articulation axis (20) of each actuator (18) connected to the relative leg (4, 4') is placed at a height not lower than the articulation axis (16) of the actuator itself connected to the respective base (6).

6. Lifting machine according to one or more of the preceding claims, characterized in that In the lowered elevator configuration, the at least one carriageway (2) accommodates in its interior a respective leg (4, 4'), an actuator (18, 18') associated with the leg (4, 4') and a base (8) articulated to the leg (4, 4').

7. Lifting machine according to one or more of the preceding claims, characterized in that For each flexible traction element (22, 22', 22"), it comprises an additional deflection member (36) mounted on the corresponding lane (2), and the deflection member (36) is arranged to ensure that at least one straight section of the flexible traction element extending from the deflection member (36) to the carriage (14) is parallel to the lane (2).

8. Lifting machine according to one or more of the preceding claims, characterized in that The flexible traction elements (22, 22') belong to a single flexible element (22") which is closed into a loop and presents parallel straight sections, each of which is connected to a pulley (14).

9. Lifting machine according to one or more of the preceding claims, characterized in that It comprises an additional pulley (40) sliding along the track (2) in the space defined by the pulley (14), the legs (4, 4') being hinged to the pulley (14), and also comprises a rigid rod (38) connecting each pulley (14) to the corresponding additional pulley (40), one end of the flexible traction element (22, 22', 22") being fixed to the additional pulley (40) after being transmitted through the corresponding vertical axis transmission component (24, 24') fixed on the track, and the transmission component (24, 24') is located in the middle position between each first slide (14, 14') and the corresponding additional slide (40).

10. The lift according to claim 9, characterized in that The rods (38) travel in respective longitudinal channels obtained in the lane (2).

11. Lifting machine according to one or more of the preceding claims, characterized in that The flexible traction element (22, 22', 22") belongs to the group including cables, ropes, belts and chains, and the transmission member (24, 24') and the deflection member (36) are configured to be coupled to the flexible traction element (22, 22', 22").

12. Lifting machine according to one or more of the preceding claims, characterized in that Each transmission member (24, 24') and / or each deflection member (36) is mounted on the corresponding lane (2) with an elastic yielding device inserted.

13. The lift according to claim 12, characterized in that Each transmission member (24, 24') and / or each deflection member (36) is mounted on a pin (26) sliding along the track (2) and is associated with preloaded elastic means (34) tending to keep the pin in the correct working position.

14. Lifting machine according to one or more of the preceding claims, characterized in that In any lifting state of the lift, the distance between the articulation axes (10) connecting the legs (4, 4') to the corresponding base (8) is smaller than the distance between the articulation axes (12, 12') connecting the legs (4, 4') to the corresponding track (2).

15. Lifting machine according to one or more of claims 1 to 13, characterized in that In any lifting state of the lift, the distance between the articulation axes (10) of the legs (4, 4') at the respective bases (8) is greater than the distance between the articulation axes (12, 12') of the legs (4, 4') connected to the respective rails (2).

16. Lifting machine according to one or more of the preceding claims, characterized in that The lift is configured so that the ratio of the maximum lifting stroke of the track (2) to the length of the legs (4, 4') is not less than 1, the maximum lifting stroke being measured with reference to the articulation axis (12, 12') connecting the track (2) to the legs (4, 4'), the length of the legs (4, 4') being measured between the articulation axis (12, 12') connected to the track (2) and the articulation axis (10) connected to the base (6).

17. Lifting machine according to one or more of the preceding claims, characterized in that The lift comprises a pair of carriageways (2), each carriageway being supported by two legs (4, 4').

18. Lifting machine according to one or more of the preceding claims, characterized in that Each lane (2) is configured to project a continuous longitudinal step (6) at least in correspondence with its inner longitudinal edge for supporting the inner crosspiece.

19. Lifting machine according to one or more of claims 1 to 16, characterized in that The lift comprises a single carriageway (2) to which a plurality of crosspieces are applied, which crosspieces project laterally from both sides of the carriageway itself and are configured to support motor vehicles.

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