MOVABLE CONVEYORS FOR MOVING A FOUR-WHEEL VEHICLE

Abstract

The disclosure relates to a conveyor for moving four-wheel vehicles. The conveyor includes a chassis having stowable extensions movable between a position in which the extensions make it possible to move the chassis under the vehicle and a position in which the extensions make contact with the treads of the wheels. The chassis is telescopic and includes two segments that each have a pair of arms. At least one of the arm pairs is hinged so as to enable movement between a position perpendicular to the longitudinal axis of the chassis with an extension at least equal to the track width of the vehicle and a folded-up position that is to occupy a width less than the distance between the inner flanks of the wheels of the vehicle. The segments are movable between a position where the arms are not in contact with the wheels and a position where each arm makes contact with the tread of one of the wheels so as to raise or lower the vehicle.

Claims

1. A conveyor for moving a four-wheel vehicle, comprising: a frame provided with laterally stowable extensions movable between a position in which they allow the frame to move under the vehicle, and a position in which they come into contact with treads of wheels; the frame being telescopic and comprising two segments each carrying a pair of arms; the at least one of the pairs of arms being articulated to allow movement between a position perpendicular to the longitudinal axis of the frame with an extension at least equal to a track width of said vehicle, and a folded-up position that is to occupy a width less than a distance between inner sidewalls of the vehicle's wheels; the segments being movable between a position in which the arms are not in contact with the wheels, and a position in which each arm makes contact with the tread of one of the wheels, so as to raise or lower the vehicle.

2. The conveyor of claim 1 wherein the raising or lowering of the vehicle is ensured by clutching the treads with the arms to exert a pressure in two opposite longitudinal directions on either side of each wheel, and produce a vertical wheel travel component resulting from the tangent angle of the tread on the contact line between the arm and the tread.

3. The conveyor of claim 1 wherein the raising or lowering of the vehicle is ensured by a first lifting means installed between the first segment and a first plate carrying a first haulage system, and a second lifting means installed between the second segment and a second plate carrying a second haulage system.

4. The conveyor of claim 1 wherein the pair of articulated arms is movable transversely.

5. The conveyor of claim 1, wherein the said pair of articulated arms is movable by pivoting extensions.

6. The conveyor of claim 1, wherein the raising of the vehicle is ensured by an interaction, on either side of the vehicle, between the rear arm with the rear of the tread area of the rear wheel on the one hand, and, on the other, between the front arm with the front of the tread area of the front wheel.

7. The conveyor of claim 1, wherein the raising of the vehicle is ensured by an interaction, on either side of the vehicle, between the rear arm with the front of the tread area of the rear wheel on the one hand, and, on the other, between the front arm with the rear of the tread area of the front wheel.

8. The conveyor of claim 1, wherein the raising of the vehicle is ensured by an interaction between one of the arms with one of the portions of the wheel's tread and an additional arm coming into contact with an opposite portion of the same wheel's tread.

9. The conveyor of claim 1, wherein the frame comprises the two segments each having a haulage system, one of the haulage systems being rear-wheel driven, the at least one of the haulage systems being front-wheel driven.

10. An automatic parking system comprising: at least one conveyor for moving a four-wheel vehicle; a frame provided with arms that are movable between a position in which they allow moving the frame under the vehicle, and a position in which they come into contact with treads of wheels; the frame being telescopic and comprises two segments each carrying a pair of arms, at least one of the pairs of arms being articulated to allow movement between a position perpendicular to a longitudinal axis of the frame with an extension at least equal to a vehicle track, and a folded-up position to occupy a width that is lower than a distance between inner sidewalls of the vehicle's wheels; and the segments being movable between a position in which the arms are not in contact with the wheels, and a position in which each arm comes into contact with the tread of the wheels, to raise or lower the vehicle.

11. The automatic parking system of claim 10 further comprising a computer operably controlling the haulage of the conveyor under the chassis of the vehicle, by a displacement of the conveyor along the longitudinal axis of the vehicle, then raising the vehicle by moving the conveyor segments and arms, then hauling the conveyor to a destination location, and then releasing the vehicle by moving the arms and removing the conveyor through a displacement along the longitudinal axis of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be best understood when reading the following detailed description thereof, which refers to a non-restrictive exemplary embodiment, illustrated by the appended drawings, wherein:

[0018] FIG. 1 shows a schematic perspective view of a conveyor according to an exemplary embodiment of the invention;

[0019] FIGS. 2 to 8 show schematic views of the vehicle and of the conveyor at successive stages of loading;

[0020] FIG. 9 shows a perspective view corresponding to an alternative embodiment of the invention; and

[0021] FIGS. 10 to 11 show schematic views corresponding to the alternative embodiment of the invention in FIG. 9.

DETAILED DESCRIPTION

[0022] FIG. 1 shows a perspective view of an exemplary conveyor according to the invention. It comprises a front block (1) enclosing a motor driving a single steering wheel (alternatively, two steering wheels can be provided). This front block (1) also contains the electronic circuits and a computer handling the autonomous guidance of the conveyor. This front block (1) is topped by a wide-angle laser range finder (10) providing real-time information to the computer.

[0023] A telescopic arm (2) extends towards the rear from this front block (1). A retractable part (3) of this arm is actuated by a cylinder or a linear actuator, e.g. a worm gear.

[0024] The first segment of the arm (2) has a front transverse arm (25) that is fixed and which supports two fixed extensions (21, 22), as well as two stowable extensions (23, 24), rotatable in relation to pivots (26, 27). They are driven by cylinders, to be able to move between a cleared position, when loading the vehicle, and a locking stowed position, when transporting the vehicle. In the stowed position, the spacing of the extensions (21, 23) and (22, 24) is determined so as to come into contact with the front and rear sidewalls of the vehicle's tyre and by clutching it to ensure the vehicle is raised. To this end, the front extensions (21, 23) have an inclined ramp (28, 29). When the extensions (22, 23) are folded into the locking position, they prevent the vehicle from moving in relation to the conveyor.

[0025] The rear part (3) of the arm (2) also comprises a transverse arm (35) extended by two extensions (31, 32) that can be moved in relation to pivots (36, 37). When loading the vehicle, these extensions (31, 32), as well as extensions (21, 22), are adjusted substantially longitudinally, parallel to the main axis of the arm (2). The length L of the arms (25, 35), measured respectively between pivots (26, 27) and (36, 37) is less than Vmin?Lmin, where: [0026] V.sub.min refers to the usual and minimal track of a car, typically 1,600 millimetres [0027] L.sub.min refers to the usual width of a car's tyre, typically 220 millimetres.

[0028] The length L of the arms is therefore typically less than 1,400 millimetres, and preferably of the order of 1,200 millimetres. The length of the fixed (21, 22) and movable (23, 24), (33, 34) extensions is determined to be half the width Imax corresponding to the width of a large car less the length of the arm (25, 35), typically 500 millimetres for each of the extensions.

[0029] The conveyor can thus be placed in the axis of the vehicle to allow for the free passage of the arm (2) under the vehicle's chassis with the extensions (23, 24, 33, 34) in folded-up position, adjusted substantially longitudinally, until the ramps (28, 29) of the fixed arms (20, 21) come to rest against the front wheels of the vehicle. The extension (3) of the arm (2) is moved to adjust to the wheelbase of the car to be loaded. The extensions (23, 24, 33, 34) are then moved to come into a transverse position, in contact with the rear sidewalls of the vehicle's wheels.

[0030] The extension (3) is then driven forward to ensure that the vehicle's wheels are locked. The front block (1) comprises four ultrasonic telemetry sensors (41 to 44) delivering signals according to the distance of the vehicle's bumper. The front arm (25) comprises two force sensors (46, 47) to detect and confirm that the vehicle has been grasped. The rear arm (35) includes two short-range scanning laser telemetry sensors (48, 49) to detect the wheels and any obstacles. The frame formed by the arm (2, 3) and the arms (25, 35) has castors or rollers to enable rolling on the ground.

[0031] FIGS. 2 to 8 show schematic views of the vehicle and of the conveyor at successive stages of loading. As shown in FIG. 2, the conveyor is initially correctly placed in front of the car, which is parked at a stowage location. The movable arms (22, 23, 32, 33) are folded into the longitudinal position.

[0032] The laser range finder (10) provides information to control the placement of the conveyor. The short-range laser range finders (46, 47) detect the front wheels of the vehicle. The conveyor aligns itself with the car.

[0033] In the next step (FIG. 3), the conveyor places the arm (2) under the car, while aligning, lengthwise, the axis of the arm (2) and the longitudinal axis of the vehicle. The ultrasonic range finders (41 to 43) detect the vehicle's bumper to control the stopping of the conveyor's relative movement with respect to the vehicle. The short-range laser range finders (48, 49) detect the rear wheels of the vehicle.

[0034] In the next step (FIG. 4), the movable rear extensions (32, 33) are stowed in a transverse position. The conveyor then advances until the fixed forward extensions (22, 23) come into contact with the front wheels (FIG. 5). The arm (2) adjusts its length according to the length of the front overhang estimated by the ultrasonic range finders (41 to 44).

[0035] The force sensors (46, 47) indicate that the wheels are in contact. The conveyor then adjusts (FIG. 6) the length of the rear arm (3) so that the rear extensions (32, 33) touch the rear wheels. The force sensors (48, 49) indicate that the wheels are in contact.

[0036] The movable extensions (23, 24) clamp the front wheels and raise the car onto the front and rear rollers (FIG. 7), causing the vehicle to rise. The force sensors (48, 49) confirm that the car is mounted on the rollers (FIG. 8), and the conveyor is moved automatically to take the vehicle to the target location. The laser range finder (10) will detect obstacles. It performs an emergency stop of the robot, if necessary.

Alternative Embodiment

[0037] FIGS. 9 and 11 show an alternative embodiment in which the vehicle is lifted using lifting bags (200, 300). The conveyor consists of a frame formed of two casings (2, 3) about 50 millimetres thick, connected by a pair of ROLLON-type (trademark) recirculating ball-profiled rails (250, 260). The frame thus forms a stowable platform consisting of a first segment (2) integral with the motorized block (1), and a second segment (3) that can be moved away through the action of an electric or pneumatic cylinder using the recirculating ball-profiled rails (250, 260).

[0038] The frame only consists of two stowable parts to allow for it to be adapted to the wheelbase of the vehicle to be moved. The segment (3) is provided with a pivoting plate (300) comprising light-running castors (301, 302). A lifting bag or mechanism is inserted between the structure of the segment (3) and the plate (300) so as to enable variation in height between a collapsed position, in which the segment (3) can be introduced under the vehicle, and a raised position in which it is used to lift the vehicle in such a way that its wheels are no longer in contact with the ground.

[0039] The range of motion is typically a few centimetres. The lifting bag, for example, consists of an inflatable envelope comprising two rectangular sheets of woven polyaramid. A pneumatic valve is inserted into a corner of the envelope.

[0040] Alternatively, the plate (300) is connected to the structure of the segment (3) by an extensible means such as an electric or hydraulic oil jack, with an articulated structure that can, for example, be deformed by a screw driven by an electric motor. In the same way, the assembly formed by the motorized block (1) and the segment (2) comprises a plate (200) mounted on a lifting bag or structure. The plate (200) is equipped with drive wheels (201, 202).

[0041] Alternatively, the assembly formed by the motorized block (1) and the segment (2) comprises drive wheels (201, 202) consisting of drive units as described in European Patent EP1795431. These drive units (201, 202) are provided with a steering motor comprising a steering motor shaft and a rotatable drive mechanism consisting of an electric motor, a gearbox and a brake. Alternatively, the segment (2) is combined with a pulling-pushing lift jack through a height adjustment mechanism.

[0042] In any case, the lifting mechanism controls the ground clearance of the first segment (2) so as to enable variation in height between a collapsed position, in which the segment (2) can be introduced under the vehicle, and a raised position in which it is used to lift the vehicle in such a way that its wheels are no longer in contact with the ground. The range of motion is typically a few centimetres.

[0043] The segment (3) forms a hollow casing having on each side a pair of arms (31, 33; 32, 34) articulated about pivots respectively (310, 330, 320, 340) between a position in which the arms are folded to hold a substantially longitudinal position, with an angle less than 20? with respect to the longitudinal axis, in order to reduce the width of the conveyor and allow for it to be introduced under the vehicle, between the wheels. In stowed position, the arms (31, 33, 32, 34) extend perpendicularly to the longitudinal axis. In this latter position, the inner edges of each arm rest against the tread of the car's tyre. When the lifting system is actuated, it causes the tyres to lose contact with the ground. The movement of the arms (21, 33; 32, 34) is handled by hydraulic, pneumatic or electric cylinders (311, 331; 321, 341).

[0044] The segment (2) also forms a hollow casing having on each side a fixed arm (21, 22) and a movable arm (23, 24) hinged about pivots respectively (230, 240) between a position in which the arms are folded to hold a substantially longitudinal position, with an angle less than 20? with respect to the longitudinal axis, in order to reduce the width of the conveyor and allow for it to be introduced under the vehicle, between the wheels. In stowed position, the arms (21, 23, 22, 24) extend perpendicularly to the longitudinal axis. In this latter position, the inner edges of each arm rest against the tread of the car's tyre. When the lifting system is actuated, it causes the tyres to lose contact with the ground. The movement of the arms (23, 24) is handled by hydraulic, pneumatic or electric cylinders (231, 241). The movement of segment (3) in relation to segment (2) allows for the conveyor to be adjusted to the wheelbase of each vehicle.