Trolley to move motor vehicles in a car park

Abstract: Trolley to move a motor vehicle (15) inside a car park (10), having lifting means (18a, 18b) which comprise for each wheel (55) of said motor vehicle a pair of arms (26) able to move selectively towards each other to lift said wheel (55) from the ground (21), and alignment means (23a, 23b) which comprise, for each pair of front and rear wheels (55), two thruster elements (42) able to move in opposite directions to each other towards a respective wheel (55) to push it outwards until the longitudinal axis of said motor vehicle (15) and said reference axis (25) of said trolley (20) coincide.

Description: FIELD OF THE INVENTION This invention concerns a trolley able to move motor vehicles in an automated car park comprising a plurality of parking spaces. To be more exact, the trolley according to the invention is able to move a vehicle automatically from the entrance to the car park to a defined parking space and, subsequently, from said parking space to the exit of the car park, also in co-operation with a lift. BACKGROUND OF THE INVENTION The state of the art includes a trolley to move motor vehicles in an automated car park as, for example, in US-A-3 435 965 comprising an underground or elevated structure which defines a plurality of parking spaces in each of which a motor vehicle is able to be parked. The trolley is able to pick up a motor vehicle left by the user at a delivery point and to park it in a free parking space. At a later time, the trolley is able to collect the motor vehicle from the relative parking space and to deposit it at the collection point. In order to carry out these operations, the automated trolley is able to position itself under the motor vehicle, to lift it from the ground and to move it along preferential paths. Conventional trolleys are able to lift the front wheels of the motor vehicle to move it from one place to another in the car park, letting only the rear wheels rest on the ground. Such trolleys are not able to align the motor vehicle with respect to themselves, and this is a problem especially in automated car parks where the width of each parking space is extremely limited in order to exploit the spaces available to the utmost. At present, in fact, the motor vehicle and the trolley must be aligned by the user himself when, at the moment he delivers the motor vehicle, he must ascertain that he has positioned it correctly at the delivery point. This procedure is a subjective one, and hence is not very reliable. A mistaken positioning of the motor vehicle with respect to the trolley can cause imbalance to the movement organs of the trolley itself, it can cause damage to the motor vehicle and to the structure of the car park or may even constitute a danger for other users and workers. For this reason, in automated car parks using trolleys which are not able to center the motor vehicle automatically, the parking spaces must be very wide and therefore, given the same size, it is not possible to achieve car parks of great capacity. The present Applicant has devised and embodied this invention to overcome the shortcomings of automated trolleys such as have been proposed until now, and to obtain further advantages. SUMMARY OF THE INVENTION The invention is set forth and characterized in the main claim, while the dependent claims describe other innovative characteristics of the invention. One purpose of the invention is to provide a self-moving trolley for automated car parks able to perform, quickly and with extreme safety, the operations to park and deliver any motor vehicle, irrespective of the dimensions thereof. Another purpose is to make possible to reduce the width of the parking spaces and therefore to increase, given the same dimensions, the capacity of the automated car parks. A further purpose of the invention is to provide a trolley which can be easily employed in existing car parks too. The trolley according to the invention is able to lift any motor vehicle and center it with respect to the trolley itself so as to distribute the load uniformly and to prevent danger to users, motor vehicles and the structures of the car park. The trolley according to the invention is able to position itself under the vehicle to be moved and is equipped with lifting means able to lift said motor vehicle to a defined height from the ground, alignment means able to correctly position the motor vehicle on the trolley and moving means able to move it from one part of the car park to another, along preferential paths. The extremely limited maximum width of the trolley and its ability to center the motor vehicle lifted make possible to achieve much narrower parking spaces than those in car parks using trolleys of a conventional type. To give an example, the trolley according to the invention in working conditions reaches a maximum width of about 180 cm, so that the width of the parking space can be reduced to about 200 cm, compared with the 230÷250 cm of present parking spaces for trolleys of a conventional type. The lifting means according to the invention comprise, for each wheel of the motor vehicle, a pair of arms arranged at a defined height from the ground and able to move selectively between an inactive position wherein they do not interfere with the wheels of the motor vehicle and a working position wherein they are positioned on opposite sides with respect to the axis of the wheel and draw progressively nearer to each other until a pre-defined distance. This distance is less than the value of the diameter of the wheel and the height of the arms from the ground is less than the radius of the wheel. The alignment means according to the invention are activated only after all the wheels of the motor vehicle have been lifted from the ground and comprise, for each pair of wheels which are opposite each other with respect to the longitudinal axis of the motor vehicle, two thruster elements able to move, in opposite directions to each other, towards the outside of the trolley in the direction of a respective wheel. The thruster elements are able to move the motor vehicle laterally, acting on the inner part of the wheel, until the longitudinal axis of the motor vehicle and one reference axis of the trolley, for example, the median axis, coincide. Each thruster element is located between a pair of arms and therefore causes the wheels to slide sideways on the arms. According to the invention, the arms are shaped so as to facilitate this lateral sliding and the lifting of the wheels. In one embodiment, the arms comprise at least a roller equipped with an idler movement, which assists the lifting of the wheel, and the surface is carefully finished, which assists the lateral sliding of the wheel. In one embodiment of the invention, the counter-positioned thruster elements defining the same pair are able to protrude from the trolley to an equal extent; in this way, when both the thruster elements touch a respective wheel, the longitudinal axes of the trolley and of the motor vehicle coincide. In the preferential embodiment of the invention the trolley is equipped with front lifting means and rear lifting means which are independent of each other, and front alignment means and rear alignment means which are independent of each other. According to another characteristic of the invention, the rear lifting means and the rear alignment means and/or the front lifting means and the front alignment means are able to vary their position along the trolley so as to adapt to any interaxis whatsoever of the wheels of the motor vehicle to be moved. BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the invention will become clear from the following description, given as a non-restrictive example, of a preferential form of embodiment of the invention with reference to the attached drawings wherein: Fig. 1 is a simplified side view of an automated car park employing a trolley according to the invention; Fig. 2 shows an exploded view from above of the trolley according to the invention; Fig. 3 is a side view of Fig. 2; Fig. 4 is a longitudinal section of the trolley according to the invention; Fig. 5 is a view from A to A of Fig. 2; Fig. 6 shows a section from B to B of Fig. 2; Fig. 7 shows a section from C to C of Fig. 2; Fig. 8 shows a section from D to D of Fig. 2; Fig. 9 shows a section from E to E of Fig. 2; Fig. 10 shows a plane view of a delivery or collection point without the trolley according to the invention; Fig. 11 shows a variant of Fig. 10; Figs. 12 and 13 show respectively a transverse section and a longitudinal section of Fig. 11; Fig. 14 shows a variant of Fig. 2; Fig. 15 shows the longitudinal section of Fig. 14; Fig. 16 shows the section from F to F of Fig. 14; Fig. 17 shows the section from G to G of Fig. 14; Fig. 18 shows the section from H to H of Fig. 14; Fig. 19 shows another variant of Fig. 2; Fig. 20 shows the longitudinal section of Fig. 19. DETAILED DESCRIPTION OF PREFERENTIAL EMBODIMENT Fig. 1 shows an automated car park 10 comprising a vertical, elevated structure able to define a plurality of parking spaces 13, a delivery point 11, a collection point 12, a lift 14 and a trolley 20 according to the invention. The trolley 20 is able to lift a motor vehicle 15 from the surface of the points 11 and 12, from the lift 14 and the parking spaces 13, to transport it from one place to another inside the car park 10. Thus, during the parking operations, the trolley 20 is able to transport the motor vehicle from the delivery point 11 into the lift 14 and from the latter to a defined parking space 13 and, during the pick up operations, is able to transport the motor vehicle 15 from said parking space 13 into the lift 14 and from the latter to the collection point 12. The trolley 20 and the lift 14 are moved in a completely automatic manner, managed by a programmable control unit which is not shown in the drawings. The trolley 20 according to the invention comprises a bearing frame 16, of a conformation able to position itself without interference under the motor vehicle 15. In this case, the points 11 and 12, the parking spaces 13 and the lift 14 are each equipped with their own channel 19 (Figs. 5-13) inside which the trolley 20 is able to move, by means of wheels 17, to position itself under the motor vehicle 15. The front wheels 17 are connected to an electric motor 22 commanded by the control unit according to the signals received from appropriate end-of-travel elements, not shown here, provided inside every channel 19 and/or on the frame 16. The motor 22 is equipped with a device able to regulate the acceleration and deceleration thereof, so that the trolley 20 is not subjected to sudden movements which might compromise the safety of the motor vehicle 15. The frame 16 defines a box-like structure able to contain the functional organs of two lifting assemblies, front 18a and rear 18b, able to lift the motor vehicle 15 with respect to the ground 21, and two alignment assemblies, front 23a .and rear 23b, able to center the motor vehicle 15 with respect to the trolley 20 (Figs. 5-9). In the embodiment shown, the trolley 20 is equipped, on each of its two long sides, with wheels 24 (Fig. 3) with a vertical axis of rotation and idler movement, able to slide on the side walls of the channel 19 and therefore to prevent dragging of the bearing frame 16 on said walls (Figs. 5-9). Each lifting assembly 18a and 18b comprises two pairs of horizontal arms 26, each located on the upper part of the frame 16 near its long side and on opposite sides with respect to the longitudinal axis 25 of the trolley 20 (Fig. 2). Each arm 26 supports a roller 27 equipped with idler movement and is orthogonally coupled to the upper end of a vertical pin 28 connected, as will be described hereafter, to an electric motor 29 of the reversible type. The electric motor 29, controlled by appropriate end-of-travel means which are not shown here, is able to make the pins 28 rotate to selectively take each arm 26 into two distinct positions: a first position, or inactive position, wherein the arm 26 is arranged parallel to the longitudinal axis 25 of the trolley 20, keeping inside the bulk of the bearing frame 16, and a second position, or working position, wherein the arm 26 is arranged orthogonal to the longitudinal axis 25, protruding from the bearing frame 16. As shown in Fig. 2, the arms 26 constituting the same pair of the lifting assembly, 18a or 18b, that is to say, those located on the same side of the trolley 20, are able to move towards each other in order to grip between them a wheel 55 of the motor vehicle 15 in order to lift it from the ground 21 (Fig. 3). The wheel 55 is lifted without any damage to the tyres or other parts of the motor vehicle 15 since the rollers 27, equipped with idler movement, are able to follow the profile of the wheel 55, whatever the width and the diameter "D" may be, remaining continuously in contact therewith. The arms 26 are able to draw close to each other to a distance "x", less than the diameter "D" of the wheel 55 and their height "h" from the ground 21 is less than the radius "r" of the wheel 55 (Figs. 3, 5). In this case, the motor 29 is connected to the four vertical pins 28 by means of a kinematic chain comprising two bevel gears 31 able to connect the shaft 30 of the motor 29 to respective lower transverse shafts 32 and two flexible transmissions 50, for example consisting of belts or chains, able to connect each lower transverse shaft 32 to a respective upper transverse shaft 33. The two ends of each upper transverse shaft 33 are connected, by means of a respective bevel gear 34, to a corresponding vertical pin 28 of two arms 26 which are specular with respect to the longitudinal axis 25 (Fig. 6). In the trolley 20 according to the invention, while the lifting assembly 18a is solidly coupled with the bearing frame 16, the rear lifting assembly 18b is able to move along the same frame 16 between a position, indicated in Fig. 3 by a line of dashes, wherein it is located at a minimum distance "d1" from the front moving assembly 18a, and a position, indicated in Fig. 3 by a continuous line, wherein it is located at a maximum distance "d2" from the front moving assembly 18a. This allows to adapt the trolley 20 to the interaxis of the wheels 55 of the motor vehicle 15 and, therefore, to lift and move any type of motor vehicle. In this case, the lifting assembly 18b is installed on a slider 35 able to slide on the frame 16 by means of lower wheels 36 able to rest on the inner bottom wall of the frame 16 and side wheels 37 able to rest on the inner side walls of the frame 16 (Fig. 9). The slider 35 is translated along the frame 16 by activating a reversible-type electric motor 38 solid with the frame 16. The motor 38 is connected, in this case by means of chains 40, to two parallel threaded bars 39, coupled at the two ends and free to rotate, to the bearing frame 16 (Fig. 2). The two threaded bars 39 are inserted into respective elements 41, equipped with lead screws, solid with the slider 35. In this way, the rotation in one direction or the other of the motor 38, and therefore of the two threaded bars 39, causes the rear lifting assembly 18b to be distanced from, or brought nearer to, the front lifting assembly 18a. The lifting assemblies, front 18a and rear 18b, differ from each other in that the front assembly 18a is solid with the bearing frame 16 whereas the rear assembly 18b is installed on the slider 35. Moreover, the rear lifting assembly 18b has the innermost pair of arms 26 and the outermost pair of arms 26, in the direction of the length of the trolley 20, which are autonomous since two independent motors are provided; a first motor 29 is able to command the innermost pair of arms 26 and a second motor 52 is able to command the outermost pair of arms 26. The alignment assemblies, front 23a and rear 23b, differ from each other in that the front assembly 23a is solid with the bearing frame 16 whereas the rear assembly 23b is installed on the slider 35. Each alignment assembly 23a, 23b comprises two thruster elements 42 equipped at the outer end with respective abutment elements 51 made of elastic material, for example rubber. The thruster elements 42 are parallel to each other and able to move, driven by an electric motor 43, in directions orthogonal to the longitudinal axis 25 of the trolley 20, each in the opposite direction to the other. To be more exact, each thruster element 42 is able to move between a retracted position, shown in Fig. 2 by a continuous line, wherein the abutment element 51 is contained inside the lateral edge of the trolley 20, and a position of maximum extraction, shown in Fig. 2 by a line of dashes, wherein the abutment element 51 protrudes by a defined segment with respect to said lateral edge. The movement of the two thruster elements 42 of the same alignment assembly 23 is entrusted to two pinions 45, commanded by the electric motor 43, each able to engage on a respective rack 44 provided on the inner face of the two thruster elements 42. In this case, a first pinion 45 is keyed onto the upper end of a vertical shaft 48 driven by the motor 43 by means of a bevel gear 47. The second pinion 45 on the contrary is keyed onto a vertical shaft 49 driven by a chain 46 able to close on two toothed wheels keyed respectively onto the shaft 48 and the shaft 49. The alignment assemblies 23a and 23b are activated after the motor vehicle 15 has been lifted from the ground by the two lifting assemblies 18a and 18b. When this happens, the two abutment elements 51 of the same alignment assembly 23a or 23b each draw near to a respective wheel 55 of a same axle of the motor vehicle 15. The first of the two abutment elements 51 to touch the respective wheel 55 pushes it, and therefore the whole motor vehicle 15, outwards until the second abutment element 51 also touches the respective wheel 55. This happens in great safety and without damage to the motor vehicle 15 since the abutment elements 51 act on the inner part of the rim of the wheels 55. The sliding of the tyres on the rollers 27 of the arms 26 is also facilitated by the careful surface finish of the rollers 27. The two thruster elements 42 protrude equally from the bulk of the trolley 20 and therefore, when both the abutment elements 51 touch the respective wheels 55 of the motor vehicle 15, the median point of the axle of the wheels 55 is vertically aligned with the longitudinal axis 25 of the trolley 20. When this happens, both in correspondence with the front alignment assembly 23a and also in correspondence with the rear alignment assembly 23b, the longitudinal axis of the motor vehicle 15 and the longitudinal axis 25 of the trolley 20 coincide. This makes possible to center the motor vehicle 15 perfectly on the trolley 20 and hence to move it with extreme safety inside the car park 10. We shall now see the various steps which the trolley 20 is able to carry out under the supervision of the programmable control unit. The pick-up and park cycle provides that the trolley 20 positions itself under the motor vehicle 15, left in the delivery point 11, with the arms 26 of the lifting assemblies 18a and 18b in the inactive position and the slider 35 located at the maximum distance from the front lifting assembly 18a. Then the arms 26 of the front lifting assembly 18a are taken to the working position so that the front wheels 55 of the motor vehicle 15 are raised from the ground. At this point the arms 26, located farther back than the rear lifting assembly 18b, are taken to the working position by the motor 52 while those located farther forward are left in the inactive position. Subsequently, the slider 35 is moved towards the front lifting assembly 18a until the arms 26 located farther back touch the rear wheels 55 of the motor vehicle 15. Then the arms 26 located farther forward are also taken to the working position by the motor 29, so that the rear wheels 55 of the motor vehicle 15 too are raised from the ground 21. At this point the motor vehicle 15 is completely raised from the ground 21 but, before it can be moved inside the car park 10, it must be centered on the trolley 20. To do that, the front alignment assembly 23a and the rear alignment assembly 23b are activated simultaneously so that all the abutment elements 51 of the thruster elements 42 touch a respective wheel 55 of the motor vehicle 15. In this condition, the trolley 20 can be moved from the delivery point 11 onto the lift 14 and from hence to a defined parking space 13. When the trolley 20 has reached the parking space 13, the two thruster elements 42 are taken to the retracted position and the two lifting assemblies 18a and 18b are de-activated, for example the rear one 18b first and then the front one 18a, so that the wheels 55 of the motor vehicle 15 rest on the ground of the parking space 13 and the trolley 20 can be returned to the delivery point 11 to begin a new pick-up and park cycle. The cycle to pick up the motor vehicle 15 from the parking space 13 and deliver it to the collection point 12 is substantially the same as the one described above, except that the step of centering the motor vehicle 15 on the trolley 20 may not be necessary because the motor vehicle 15 is already correctly positioned with respect to the channel 19 of the parking space 13. The thruster elements 42 may in any case be taken into the extracted position to ensure that the motor vehicle is more stable during movement. Figs. 10-13 show two different embodiments which can be employed both at the delivery point 11 and at the collection point 12 and in the lift 14, to close the channel 19 in the absence of the trolley 20. In the embodiment shown in Fig. 10, the channel 19 is closed by two movable panels 53 able to draw near each other until they touch in correspondence with the center line of the channel 19. In the variant shown in Figs. 11-13, on the contrary, a roll-up shutter 54 is provided, guided at the two ends and able to close the channel 19 lengthwise. According to the invention, the trolley 20 is able to command the opening and closing of the movable panels 53, or the roll-up shutter 54, respectively when it arrives at or leaves the site where the movable panels 53 or the roll-up shutter 54 are installed. Figs. 14-18 show another embodiment of the trolley 20 according to the invention. In this embodiment the electric motor 22 is associated with a reduction unit 56 directly connected to the axle of the wheels 17 of the trolley 20 (Figs. 14, 16). Each arm 26 is able to be moved by means of a relative electric motor 57 of the reversible type associated with a reducer 58 to which the vertical pin 28 is connected (Figs. 14, 17, 18). The movement of the thruster elements 42 of the alignment assemblies 23a, 23b is entrusted in this case to two electric motors 59 of the reversible type arranged respectively one aligned with the longitudinal axis 25 and one inclined with respect thereto. Each electric motor 59 is able to transmit movement to the thruster elements 42 by means of a respective bevel gear 60 acting on a relative vertical shaft 61. On the two vertical shafts 61 respective pinions 62 are keyed, each of which is engaged on the racks 43 of the thruster elements 42 of the same alignment assembly 23a, 23b. The slider 35 is always moved by means of the electric motor 38 which is however connected to a single threaded bar 39, arranged in an axial position, associated with a relative element 41 equipped with a lead screw. Figs. 19 and 20 show a variant of the invention in which each arm 26 of the lifting assemblies 18a and 18b is moved by a relative fluid-dynamic actuator 63. In this embodiment, each actuator 63 is associated with the relative arm 27 by means of an oscillating lever 64 able to make the vertical pin 28, on which the arm 27 is mounted, rotate. To be more exact, when the rods of the actuators 63 are in their extended condition, the arms 27 are kept in their inactive position parallel to the longitudinal axis 25 of the trolley 20. On the contrary, when the rods of the actuators 63 are retracted, the oscillating levers 64 rotate, also making the vertical pins 28 rotate and therefore the arms 27 which are positioned in their working position, orthogonal to the axis 25 (Fig. 19). According to another variant which is not shown here, the thruster elements 42 are also moved by means of fluid-dynamic actuators. It is obvious that modifications and additions may be made to this invention, but these shall remain within the field and scope thereof. For example, the motors 22, 29, 38, 43 and 52 may be connected to the respective parts to be moved by means of kinematic chains of a different type from that shown here. Moreover, the slider 35 may move on guides, such as rails or tracks, instead of on wheels. The slider 35 can also be moved by means of other systems than those described here, for example of the hydraulic type or similar. Or the rear lifting assembly 18b, like the front lifting assembly 18a, may be equipped with a single motor 29 and decoupling devices can be provided, which can be activated selectively, keyed onto the shaft 30 so as to make the front and rear arms 26 independent of each other. Furthermore, instead of the movable panels 53 or the roll-up shutter 54, different means may be included to close the channel 19 in the absence of the trolley 20; in one possible form of embodiment, these means comprise a platform which can be selectively raised by means of actuators of a hydraulic type or similar. It is also obvious that the trolley 20 is provided, even though not described or shown, with safety devices, with end-of-travel means which regulate its every manoeuvre with precision, and also photocells, sensors and micro-switches able to signal the various states of the trolley 20 to the control unit. It is also obvious that, although this description refers to a specific example, a person of skill in the art shall certainly be able to achieve many other equivalent forms of automated trolley, but these shall all come within the field and scope of this invention as defined in the claims.

Claims: Trolley to move a motor vehicle (15) to transport it inside a car park (10), comprising lifting means able to lift said motor vehicle (15) from the ground (21) and alignment means able to align and center said motor vehicle (15) with respect to a reference axis (25) of said trolley (20), the trolley being characterized in that said lifting means (18a, 18b) comprise, for each wheel (55) of said motor vehicle (15), a pair of arms (26) arranged at a defined height (h) from the ground (21) and able to move selectively towards each other between an inactive position wherein they do not interfere with the corresponding wheel (55) of said motor vehicle (15), and a working position wherein they are arranged on opposite sides with respect to the axis of said wheel (55) and keep it raised from the ground (21), said arms (26) being able to approach each other progressively to a pre-defined distance (x) for each pair of wheels (55) opposite each other with respect to the longitudinal axis of said motor vehicle (15), and in that said alignment means (23a, 23b) comprise, for each pair of front and rear wheels (55), two thruster elements (42) arrange between said pair of wheels (55) and able to move in opposite directions to each other towards a respective wheel (55) to push it outwards until the longitudinal axis of said motor vehicle (15) and said reference axis (25) of said trolley (20) coincide. Trolley as in Claim 1, characterized in that said distance (x) between said arms (26) in the near position is less than the diameter (D) of said wheel (55). Trolley as in Claim 1, characterized in that said height (h) of said arms (26) from the ground (21) is less than the radius (r) of said wheel (55). Trolley as in Claim 1, characterized in that it comprises front lifting means (18a) and rear lifting means (18b) autonomous from each other and able to lift respectively the front part and the rear part of said motor vehicle (15). Trolley as in Claim 1, characterized in that it comprises front alignment means (23a) and rear alignment means (23b) autonomous from each other and able to align and center respectively the front part and the rear part of said motor vehicle (15) with respect to said reference axis (25) of said trolley (20). Trolley as in claims 4 and 5, characterized in that said front lifting means (18a) and said front alignment means (23a) and/or said rear lifting means (18b) and said rear alignment means (23b) are able to move along said trolley (20) to adapt to the interaxis of the wheels (55) of said motor vehicle (15). Trolley as in claims 4 and 5, characterized in that said front lifting means (18a) and said front alignment means (23a) and/or said rear lifting means (18b) and said rear alignment means (23b) are installed on a slider (35) able to slide along said trolley (20). Trolley as in Claim 7, characterized in that it is able to define a box-like body and that said slider (35) is equipped with lower wheels (36) and side wheels (37) able to slide respectively on the bottom and on the side walls of said box-like body. Trolley as in Claim 7 or 8, characterized in that motor means (38) are able to make rotate at least a threaded bar (39), solid with said trolley (20), inserted into an element equipped with a lead screw (41) solid with said slider (35), so that activating said motor means (38) in one direction or the other causes the slider (35) to slide on said trolley (20). Trolley as in Claim 9, characterized in that said motor means (38) are able to make rotate two threaded bars (39) which are parallel and distanced from each other. Trolley as in Claim 1, characterized in that each of said arms (26) is provided at one end with a vertical pin (28) and in that motor means (29, 57) are provided to rotate said pin (28) between said inactive position wherein said arm (26) is located within the bulk of said trolley (20) and said working position wherein said arm (26) protrudes laterally from said trolley (20). Trolley as in Claim 11, characterized in that said motor means (29) are connected to said vertical pin (28) by means of a kinematic chain comprising two bevel gears (31) able to connect the shaft (30) of said motor (29) to respective lower transverse shafts (32) and two flexible transmissions (50) able to connect each of said lower transverse shafts (32) to a respective upper transverse shaft (33) equipped at the two ends with a bevel gear (34) able to connect it to said vertical pin (28). Trolley as in Claim 11, characterized in that said motor means (57) are connected to said vertical pin (28) by means of reduction means (58). Trolley as in Claim 1, characterized in that said arms (26) are associated with fluid-dynamic actuator means (63) able to rotate them between said inactive position and said working position. Trolley as in Claim 14, characterized in that said fluid-dynamic actuator means (63) are associated with said arms (26) by means of oscillating lever means (64). Trolley as in Claim 1, characterized in that each of said thruster elements (42) is located between a pair of said arms (26) and causes said wheels (55) to slide laterally on said arms (26) when the latter are in said working position. Trolley as in Claim 1, characterized in that each of said arms (26) comprises at least a roller (27) equipped with idler movement. Trolley as in Claim 1, characterized in that each of said thruster elements (42) comprises at least a bar equipped at the outer end with an abutment element (51) able to co-operate with the inner part of a respective wheel (55) of said motor vehicle (15), said bar being guided horizontally and drive means (43, 59) being provided to take said bar selectively to a retracted position wherein said abutment element (51) is contained within the lateral edge of said trolley (20) or to an extracted position wherein said abutment element (51) protrudes with respect to said lateral edge. Trolley as in Claim 18, characterized in that said thruster elements (42) are able to protrude in equal measure from said trolley (20) so that when the abutment elements (51) of two thruster elements (42) defining the same alignment means (23a or 23b) touch the respective wheels (55) of said motor vehicle (15), the longitudinal axis of said motor vehicle (15) coincides with said reference axis (25) of said trolley (20). Trolley as in Claim 18, characterized in that said bar is equipped at least on one side with a rack (44) and said drive means (43, 59) comprise at least a motor able to make rotate, in one direction or the other, at least a pinion (45, 62) able to engage on said rack (44). Trolley as in Claim 1, characterized in that it is able to move inside a channel (19) made in the ground (21), to position itself under said motor vehicle (15). Trolley as in Claim 21, characterized in that it is able to selectively activate and de-activate means (53, 54) to close said channel (19).

Inventors: FABRIS DOMENICO, FABRIS, DOMENICO
Applicants: PINETA SRL
Application year: 2000
Main classification: E04H6
IPC codes: E04H6