AT16499U1 - wheelchair - Google Patents

Abstract

The invention relates to a wheelchair (10) comprising a vehicle unit (11) comprising a control device (16) for controlling a vehicle drive (13) with two drivable wheels (14) spaced apart in a transverse direction (Q) and one between the two Wheels (14) arranged platform (15) with pressure sensors (17). The control device (16) is configured to deactivate the vehicle drive (13) if the sensor signal of the pressure sensors (17) indicates that the pressure sensors (17) are unloaded. A wheelchair seat (12) is disposed between the wheels (14) without urging the pressure sensors (17). A front support (39) and a rear support (40) can be retracted and extended by a separate electrically controllable support drive (41)

Description

The invention relates to a wheelchair with a wheelchair seat, which is mounted on a vehicle unit. The vehicle unit has a control device for controlling a vehicle drive. The vehicle drive is designed with one axle and two drivable wheels which are arranged at a distance in a transverse direction. The wheels can have independent rotational speeds. The platform has pressure sensors that transmit a sensor signal to the control device. In the activated state of the vehicle unit, the control device is set up to align an approximately horizontal platform of the vehicle unit present between the wheels. If the pressure sensors indicate to the control unit that the platform is not loaded, the control device deactivates the vehicle drive or the entire vehicle unit.

Such a vehicle unit is known from two-wheeled self-balancing vehicles, for example from the vehicle of the “Segway®” brand. Such vehicles are usually driven while standing. If a driver is standing on the platform, the pressure sensors are loaded and report the presence of the driver to the control device. If the driver loses his grip on the vehicle, the pressure sensors are relieved accordingly and the control device initiates the deactivation of the vehicle drive in order to prevent the vehicle from moving without a driver.

WO 2012/017335 A1 describes a wheelchair that is constructed on the basis of a vehicle unit described above. The wheelchair seat is connected to the platform of the vehicle unit via an elaborate lever mechanism. This lever mechanism is designed in such a way that the pressure sensors on the platform are only loaded if, on the one hand, a person has been seated in the wheelchair seat and, on the other hand, a mechanical support system has been retracted by a hand lever from the person sitting in the wheelchair seat.

The lever mechanism described is relatively complex since the two conditions, namely the presence of a person in the seat and the retraction of the support system, are mechanically linked and only then should the pressure sensors be loaded. The installation space required is large and, depending on the design, cannot be reduced arbitrarily. A minimum seat height above the floor can therefore not be undercut.

Based on the known wheelchair, it can be regarded as an object of the present invention to provide an improved support system. This object is achieved by a wheelchair with the features of claim 1.

The wheelchair has a vehicle unit with a control device for controlling a vehicle drive with two drivable wheels arranged in a transverse direction at a distance and a platform arranged between the wheels. The platform has accessible pressure sensors on its top, which transmit a sensor signal to the control device. When the vehicle unit is activated, the control device is set up to align the platform essentially horizontally and for this purpose to drive the two vehicle wheels independently of one another in the required direction of rotation. The control device is also set up to deactivate the vehicle drive when the sensor signal indicates that the pressure sensors are not loaded. This functionality of the vehicle unit corresponds to a self-balancing vehicle known per se, which is offered, for example, under the "Segway®" brand.

[0007] The wheelchair is constructed on the basis of this vehicle unit. A wheelchair seat is attached to the platform without stressing the pressure sensors. The pressure sensors are therefore not loaded, regardless of whether a person is sitting in the wheelchair seat or not.

The wheelchair has an electrically controllable support device. The support device has at least one front support arranged at the front of the vehicle unit and at least one rear support arranged at the rear of the vehicle unit. In a preferred embodiment

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AT 16 499 U1 2019-11-15 Austrian patent office there are two front supports and two rear supports. The two front and rear supports are spaced apart in the transverse direction.

Both the at least one front support and the at least one rear support can be retracted and extended by a separate electrically controllable prop drive. The actuation of the prop drive of the prop device can be triggered, for example, by means of an electrical control signal on a control unit by a person sitting on the wheelchair seat. The independently operable prop drives for the at least one front support and the at least one rear support make it possible to compensate for unevenness in the ground. The supports can extend to different extents. In its support state, the at least one front support and the at least one rear support support the wheelchair on the ground in front of and behind the vehicle unit and prevent it from tipping over about its drive axis to the front or to the rear. As soon as a front support or a rear support has reached the ground, the assigned support drive switches off. Reaching the ground can be recognized, for example, by the fact that the torque or the current of an electric motor of the prop drive increases.

In a preferred embodiment, each prop drive has a self-locking gear. Each prop drive preferably has an electric motor and a threaded spindle that can be driven by the electric motor. In engagement with the threaded spindle is a threaded nut which, when the threaded spindle rotates, performs a linear movement for extending and retracting the relevant front or rear support.

It is advantageous if the threaded spindle is arranged within a cavity of the associated front support or rear support. This allows the space required for the prop drive to be minimized.

The retraction and extension of a front support and / or a rear support is preferably carried out by a linear movement. In one embodiment, each front support and each rear support has two support parts which can be telescopically displaced. One of the support parts serves to guide the other, retractable and extendable support part, which e.g. is rotatably connected to the nut which sits on the drivable threaded spindle.

The electric motor of each prop drive can be arranged parallel to the relevant front or rear support and preferably parallel to the threaded spindle of the prop drive.

It is also advantageous if each front support and each rear support is pivotally mounted about a pivot axis which extends in the transverse direction. This pivoting movement can enable a secure horizontal alignment of the platform when the vehicle unit is activated. If the wheelchair is parked on a slope and the supports are extended, the platform would be held at an angle to the horizontal when the vehicle unit was activated by the front or rear support. By means of the vehicle drive, the control device would try to achieve a horizontal alignment of the platform against this holding force, but this is not possible because of the supports. The advantageous pivotability of the supports about the pivot axis enables the alignment movement of the platform of the vehicle unit in the horizontal.

Preferably, each front support and each rear support is acted upon by a spring unit with a restoring moment about the pivot axis, which urges the front support or the rear support into an initial position. The pivoting of the front support and the rear support about the respective pivot axis for horizontal alignment of the platform when activating the vehicle unit can therefore take place against the spring force or the restoring torque of the spring unit. It is possible to assign a separate spring unit to each front support and each rear support or to assign a common spring unit to one or more supports.

The wheelchair can also have a blocking device that between a

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Release state and a blocking state is switchable. When the blocking device is released, the front support and / or the rear support can be pivoted about their respective pivot axis. When the blocking device is locked, pivoting about the pivot axis is blocked. There may also be several blocking devices. For example, a blocking device can be provided for a pair of a front support and a rear support.

The blocking device is preferably electrically controllable. For this purpose, it can have an electrically controllable blocking drive in order to switch the blocking device between the blocked state and the released state. The blocking drive can act on a movable rocker arm, for example. The rocker arm can assume a first tilt position and a second tilt position. In the first tilt position the blocking device is in the blocking state and in the second tilt position the blocking device is in the release state. In the first tilt position, the rocker arm can each provide a stop surface for a stop part of the front support and / or the rear support, so that the pivoting movement of the respective front support and / or rear support about the relevant pivot axis is prevented. In particular, the rocker arm in its second rocking position enables the at least one stop part to move past the stop surface, while the relevant front support and / or rear support executes its pivoting movement about its pivot axis.

It is preferred if the rocker arm can only assume the first tilt position when the front support and / or the rear support is in its initial position.

The wheelchair also has an electrically controllable activation device, to which a pressing part belongs. The pressing part can be moved between a relief position and can preferably be moved linearly. In the load position, the pressing part presses on the pressure sensors of the platform, so that the vehicle unit can be activated or remains activated. The activation device can have, for example, an electric motor with a drivable threaded spindle, while the threaded nut is fastened to the pressing part. Here, too, self-locking can be achieved, so that the pressing part can be held in the load position without electrical current being supplied to the electric motor.

Preferably, the wheelchair seat is pivotally mounted about a seat axis extending in the transverse direction. The seat axis is preferably located in the area of the front end of the seat. The wheelchair seat can be supported at a point spaced from the seat axis by a spring-damper arrangement. This increases seating comfort, especially when driving on uneven surfaces with the wheelchair.

It is also advantageous if the wheelchair seat has a spring-pivoting backrest. In a preferred embodiment, the maximum swiveling path of the backrest can be adjustable by means of a mechanical adjusting device.

[0022] Advantageous refinements of the wheelchair result from the dependent claims, the description and the drawings. Preferred embodiments of the wheelchair are explained in detail below with reference to the attached drawings. Show it:

Figure 1 Fig. 1a an embodiment of a wheelchair in a side view, 2 shows a schematic block diagram of components of a vehicle unit of the wheelchair from FIG. 1, Figure 2 1 shows a schematic illustration of an exemplary embodiment of an activation device in a relief position, Figure 3 Fig. 4 2 in a loading position, a front support and a rear support of an embodiment of a support device in the retracted state, Fig. 5 4 in the extended state,

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AT 16 499 U1 2019-11-15 Austrian Patent Office [0029] Fig. 6 [0030] Fig. 7 [0031] Fig. 8 is a schematic representation of a blocking device in a blocking state, the blocking device from Fig. 6 in a release state, an embodiment of the wheelchair seat with a spring damper arrangement in a schematic side view and a perspective view of an embodiment of an adjusting device for a backrest of the wheelchair seat.

is an embodiment of a wheelchair 10 with a vehicle unit 11. FIG. 9 [0033] In FIG.

and a wheelchair seat 12 mounted on the vehicle unit 11 with a seat surface 12a and a backrest 12b. In addition, two handles 22 arranged laterally from the seat surface 12a are provided on the vehicle unit 11.

The vehicle unit 11 (FIG. 1a) includes a vehicle drive 13, as well as two wheels 14 arranged at a distance from one another in a transverse direction Q, each of which can be driven independently in both directions of rotation by the vehicle drive 13. The vehicle drive 13 has one or more electric motors for driving the wheels 14. A platform 15, which has the vehicle drive 13, is arranged in the transverse direction Q between the two wheels 14. The vehicle drive 13 is controlled by a control device 16. The control device 16 receives sensor signals from different sensors of the vehicle unit 11.

At least one and, for example, a plurality of pressure sensors 17 are arranged on an upper side of the platform 15, each transmitting a pressure signal to the control device 16. The vehicle unit 11 can also have in the platform 15 a sensor unit 18 with at least one acceleration sensor and / or at least one tilt sensor and / or at least one gyro sensor. The at least one sensor signal from the sensor unit 18 is also fed to the control device 16. The vehicle unit 11 also has a steering control element 19. The steering control element 19 can be pivoted about an operating axis which extends at right angles to the transverse direction Q in a longitudinal direction L. The pivoting movement is detected by a steering sensor 20 and a corresponding sensor signal is transmitted to the control device 16. The sensor signals of the various sensors 17, 18, 20 which are supplied to the control device 16 are identified in FIG. 1a only in a highly schematic manner by a single arrow.

Depending on the various sensor signals, the control device 16 controls the vehicle drive 13. The wheelchair 10 can be rotated about its vertical axis and thus steered by different speeds of rotation of the two wheels 14. The sensor signals of the sensor unit 18 are evaluated in order to align the platform 15 horizontally when the vehicle unit 11 is activated. The at least one pressure sensor 17 detects whether the platform 15 is loaded or relieved on its upper side. In the unloaded state, the control device 16 deactivates the vehicle drive 13. This is intended to prevent driverless driving.

The vehicle unit 11 described above corresponds to its function as a self-balancing, single-axle vehicle with two wheels, which is offered, for example, under the “Segway®” brand.

As in known self-balancing vehicles, the wheelchair 10 has only two wheels 14. Thus, the platform 15 and thus the wheelchair seat 12 mounted on the platform 15 can tip forward or backward about an axis extending transversely when the vehicle unit 11 is deactivated and the platform 15 does not automatically align itself horizontally.

The wheelchair seat 12 is fastened to the platform 15 by means of a support structure 21 without stressing the pressure sensors 17.

To switch off the vehicle unit 11 or the vehicle drive 13 by the

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To avoid control device 16 with unloaded pressure sensors 17, the wheelchair 10 has an electrically controllable activation device 25. The activation device 25 has a pressing part 26 that can be moved between a relief position ES and a loading position BS. In the loading position BS, the pressing part 26 presses on the pressure sensors 17 of the platform 15, so that they detect a load on the platform 15 and a corresponding sensor signal to the control device 16 to transfer. In the relief position ES, the pressure of the pressing part 26 on the pressure sensors 17 is small and preferably zero, so that they recognize the relief of the platform 15 and output a corresponding sensor signal to the control device 16, which then deactivates the vehicle drive 13 or the vehicle unit 11 ,

The activation device 25 contains in the embodiment an electrically controllable activation drive 27 with an electric motor 28, a driven by the electric motor 28 threaded spindle 29 and a spindle nut 30 which moves along the threaded spindle 29 when the threaded spindle 29 by the electric motor 28 about its longitudinal axis is driven in rotation. The spindle nut 30 is fastened to the pressing part 26, so that the pressing part 26 can be moved in the direction of extension of the threaded spindle 29. The pressing part is, for example, plate-shaped and can be guided by additional guide elements 31. In the exemplary embodiment of the activation drive illustrated here, the motor shaft of the electric motor 28 is oriented at right angles to the longitudinal axis of the threaded spindle 29. A bevel gear or a crown gear or the like can be used to implement this right-angled arrangement.

The activation device 25 or the activation drive 27 is controlled via an operating element on an operating unit 35, for example an activation switch. The control unit 35 is attached laterally below the seat 12a of the wheelchair 10 in the exemplary embodiment and carries on its upper side accessible control elements for the person sitting in the wheelchair seat 12.

The wheelchair 10 is also equipped with a support device 38 which has at least one front support 39 present on the front of the wheelchair and at least one rear support 40 present on the rear side of the wheelchair 10 in the longitudinal direction L opposite. In the exemplary embodiment described here, there are two front supports 39 on the front and two rear supports 40 on the rear. The two front supports 39 are arranged at a distance from one another in the transverse direction Q. Accordingly, the two rear supports 40 are arranged at a distance from one another in the transverse direction Q on the rear. A front support and a rear support 40 located in the longitudinal direction L behind each form a pair of supports. The front support 39 and the rear support 40 of a pair of supports are preferably arranged in a common plane which extends at right angles to the transverse direction Q. A pair of supports with a front support 39 and a rear support 40 is illustrated in FIGS. 2-7.

Each front support 39 and each rear support 40 is assigned a separately electrically controllable prop drive 41. The support drive 41 for each of the supports 39, 40 is constructed identically. The supports 39, 40 can extend differently independently of one another in order to compensate for unevenness in the ground. The support drive 41 can be set up to switch off when the associated support 39, 40 has reached the ground.

Each support drive 41 includes an electric motor 42, a threaded spindle 43 which can be driven by the electric motor 42 and a spindle nut 44 which can be moved along the threaded spindle 43 (FIG. 2). The threaded spindle 43 and the spindle nut 44 of a support drive 41 are arranged in an inner cavity of the associated support 39, 40, as is illustrated schematically in FIG. 2. The associated electric motor 42 is held laterally next to the relevant support 39, 40 mechanically on the associated support 39, 40 via a flange connection 45 and coupled in terms of drive to the associated threaded spindle 43, for example via a gear transmission. The electric motor 42 can therefore be fastened in a space-saving manner parallel to the threaded spindle 43 on the outside of the associated support 39, 40. In Erstre

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AT 16 499 U1 2019-11-15 Austrian patent office direction of the assigned support 39, 40, the electric motor 42 does not extend the installation space for the support 39, 40 in question. Both the electric motor 42 and the associated support 39 or 40 as well as the threaded spindle 43 and the spindle nut 44 are arranged on the side of the flange connection 45 opposite the wheelchair seat 12 or the seat surface 12a.

Each front support 39 and each rear support 40 has two telescopically movable support parts. A first support part 46 is arranged stationary in the entry and exit direction of the relevant support 39, 40 and carries the respective electric motor 42 of the support drive 41. The other, second support part 47 can be guided in and out along the first support part 46. Depending on the direction of rotation of the threaded spindle 43, the second support part 47 is extended downward toward the base or retracted away from the base. The second support part 47 has a free end 48 which is in contact with the ground in the support position of the support device 38.

The gear connection between the electric motor 42 of a prop drive 41 and the retractable and extendable second support part 47 is designed to be self-locking. If a force is exerted on the second support part 47 in its longitudinal direction, this force is absorbed and supported by the spindle nut 44 and the threaded spindle 43. The threaded spindle 43 does not rotate relative to the threaded nut 44, so that the second support part 47 cannot move in unintentionally without a corresponding drive of the electric motor 42. Instead of the self-locking thread by means of a threaded spindle 43 and a threaded nut 44, other self-locking gears or coupling elements can also be used.

The threaded spindle-threaded nut gear arrangement provided according to the example was chosen to minimize the installation space requirement.

At least one of the two supports 39, 40 of a pair of supports is pivotally mounted about a respective pivot axis S on the support structure 21 of the wheelchair 10 via a pivot part 52. The respective pivot axis S extends in the transverse direction Q. The support structure 21 can be constructed from spars and / or struts and / or plates and connects the seat surface 12a of the wheelchair seat 12 to the platform 15. The backrest 12b of the wheelchair seat can also be attached to the support structure 21 12 may be arranged. The support structure 21 preferably contains cover plates on the outside, which cover the space below the seat 12a of the wheelchair seat 12 to the outside in a housing-like manner.

As can be seen in FIGS. 2-7, each swivel part 52 has a cuff-like shape and encloses the respectively assigned front support 39 or rear support 40. The first support part 46 and / or the second support part 47 of a respective support 39 , 40 partially or completely protrude through the inner region of the annular or cuff-shaped pivot part. In particular, the second support part 47 is guided and supported on the inside on the first pivot part 46 and is surrounded on the outside by the pivot part 52. The second support part 47 can be moved relative to the swivel part 52 in the entry and exit directions. The pivot axis of each front support 39 and each rear support 40 is arranged in a height direction H at right angles to the longitudinal direction L and at right angles to the transverse direction Q above the platform 15. The pivot axes S of the supports 39, 40 are located much closer to the platform 15 than to the seat 12a of the wheelchair seat 12. In the exemplary embodiment described here, both supports 39, 40 of a pair of supports are each pivoted about a pivot axis S. Each front support 39 and each rear support 40 is assigned a spring unit 53, which generates a restoring moment about the respective pivot axis S on the respective front support 39 or rear support 40 and urges the front support 39 or the rear support 40 into a respective starting position. In the exemplary embodiment, the supports 39, 40 are inclined in the starting position relative to the height direction H and relative to the longitudinal direction L in a plane which is spanned by the height direction H and the longitudinal direction L. The distance between a front support 39 and an associated rear support 40 of a pair of supports is smaller at the upper end assigned to the seat surface 12a than at the free ends 48 or at the two

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In its initial position, the angle of the supports 39, 40 is selected such that the second support part 47 of the front support 39 on the front of the platform 15 and the second support part 47 of the rear support 40 on the back of the platform 15 extend and retract can be. The distance between the two pivoting parts 52 of a pair of supports above the platform 15 and the position of the inner ends of the supports 39, 40 of a pair of supports in their respective starting positions is selected accordingly.

The spring unit 53 ensures that the two upper ends of the supports 39, 40 opposite the free ends 48 have a maximum distance in the longitudinal direction L in the starting position. The amount of inclination of the supports 39, 40 with respect to the height direction H is minimal in their respective initial position and increases when the relevant support 39, 40 is pivoted about the respective pivot axis S against the force of the spring device 53 or the restoring torque from its initial position ,

The spring unit 53 is only schematically illustrated in FIGS. 6 and 7. It is possible to assign a single spring unit 53 to the two supports 39, 40 of a pair of supports, which presses the two inner ends of the assigned supports away from one another. Instead of a pushing force, the supports 39, 40 could also each be assigned a spring which urges the supports 39, 40 into the starting position with a tensile force. Combinations of these are also possible. The spring unit 53 can have a spiral spring, a plate spring, an elastically deformable element or a combination thereof.

Due to the pivotable mounting of the front supports 39 and the rear supports 40, the activation of the wheelchair 10 on a surface with a gradient is improved. As soon as the vehicle unit 11 is activated, the control device tries to control the vehicle drive 13 in such a way that the platform 15 is aligned horizontally. If the supports 39, 40 are extended and support the wheelchair on the ground, it may be possible that the supports prevent horizontal alignment, for example if the ground has a slope. This can lead to high loads on the vehicle drive 13 and, depending on the drive torque provided, also to an unwanted acceleration of the wheelchair on the ground. This is because the supports 39, 40 only provide a limited frictional force on the ground and do not serve as a brake for the wheelchair 10.

Due to the pivotability of the supports 39, 40 against the restoring moment, the drive can, however, align the platform 15 horizontally without the support effect having to be completely eliminated beforehand.

Each pair of supports 39, 40 is assigned a blocking device 54, which can be controlled in an electrically controllable manner between a blocking state BZ (FIG. 6) and a release state FZ (FIG. 7). For this purpose, the blocking device 54 has an electric motor 55, a threaded spindle 56 which can be driven by the electric motor 55 and a spindle nut 57 which can be moved along the threaded spindle 56. Essentially, the drive of the blocking device 54 is constructed analogously to the activation drive 27. Instead of the pressing part 26, the drive of the blocking device 54 actuates a thrust element 58 to which the spindle nut 57 is fastened.

The thrust element 58 can be moved linearly with the spindle nut 57. A rocker arm 59, which can be pivoted about a tilt axis K, which runs in the transverse direction Q, lies on the thrust element 58. The tilt axis K of the rocker arm 59 is arranged at a distance from the support point between the rocker arm 59 and the thrust element 58. In a first tilt position KS1, the rocker arm 59 extends between two stop parts 60. The stop parts 60 can be formed, for example, by bolts or screws or other projections. Each stop part 60 belongs to a front support 39 or a rear support 40 of a common pair of supports. The stop parts are preferably arranged at a distance from the respective pivot axis S on the first support part 46. The tilt axis K is located between the two free ends of the rocker arm, the end surfaces of which are diametrically opposite to the tilt axis K each form a stop surface 61 for an associated stop part 60. The stop surfaces 61 can be aligned approximately parallel to one another. In the first tilt position KS1, the rocker arm 59 extends approximately in the longitudinal direction L.

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The front support 39 and the rear support 40 of the pair of supports can not move towards each other with their respective upper ends and thus can not be pivoted about their respective pivot axes S when the rocker arm 59 is in the first tilt position KS1. The blocking device 54 thus assumes its blocking state BZ. The stop parts 60 lie in the starting position of the front support 39 or the rear support 40 on the respective stop surface 61 and prevent the pivoting movement.

By moving the thrust element 58 with the aid of the drive of the blocking device 54, the rocker arm 59 is brought into a second rocking position KS2 (FIG. 7). In this second tilting position KS2, the abutment surfaces 61 are arranged next to the abutment parts 60 offset in the height direction H. The stop parts 61 can therefore move freely from the rocker arm 59 and the front support 39 or the rear support 40 can perform a pivoting movement about the respective pivot axis S. The blocking device 54 is in the second tilt position KS2 of the rocker arm 59 in its release state FZ.

It can also be seen that the rocker arm 59 can only assume its first rocking position KS1 when the supports 39, 40 are in their respective starting positions.

6 and 7, the axis of rotation A of the wheelchair or the wheels 14 is shown schematically as a reference point for the vehicle unit 11. When the supports 39, 40 are in their starting position, the free ends 48 in the fully extended state of the supports 39, 40 are measured a first distance z1 from the axis of rotation A in the height direction H. If the front support 39 and the rear support 40 start from a pair of supports pivoted completely from their respective starting position against the restoring moment about their respective pivot axis S, the free ends 48 have a second distance z2 from the axis of rotation A in the height direction H, the amount of which is smaller than that of the first distance z1. The difference between the two distances z1, z2 enables the support device or the existing supports 39, 40 to support the wheelchair 10 on an inclined surface, while the vehicle unit 11 or the control device 16 can horizontally align the platform 15 after activation. The required change in position of at least part of the free ends 48 of the supports 39 and 40 is made possible by the pivoting movement.

In their initial position, the supports 39, 40 are pressed by the restoring moment or the spring force against a suitable stop on the support structure 21 of the wheelchair 10. Starting from the starting position, the pivoting movement about the respective pivot axis S is therefore only possible in one direction of rotation about the respective pivot axis S, namely toward the respective other support of the same pair of supports.

8 shows a preferred exemplary embodiment of the wheelchair seat 12 or the seat surface 12a. The seat 12a is pivotally mounted about a seat axis which extends in the transverse direction Q. The seat axle is preferably provided on or near the front of the wheelchair. In the area of the rear of the wheelchair, the seat surface 12a is acted upon by a spring-damper arrangement 66. This can improve seating comfort. In one embodiment, the spring force and / or the damping effect of the spring-damper arrangement 66 can be adjustable and adapted to the weight of the wheelchair user.

The wheelchair 10 is parked on the ground for start-up and the supports 39, 40 are extended. The wheelchair user sits in the wheelchair seat 12. The vehicle unit 11 is activated via the control unit 35. With this command, the activation device 25 is brought into the load position BS and the blocking device 54 is switched to the release state in order to allow the supports 39, 40 to pivot. The platform can align itself with supports 39, 40 still in contact with the ground. The supports 39, 40 can be retracted by another command and the wheelchair is ready to drive. By moving the body forward or backward

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AT 16 499 U1 2019-11-15 Austrian patent office the wheelchair can be accelerated forwards or backwards.

The retracted supports 39, 40 are pushed into their starting position and the blocking device 54 is automatically switched to the blocking state BZ after the supports 39, 40 have been retracted.

When stopping, the procedure is essentially reversed. First, the supports 39, 40 are extended by a command via the control unit 35 and support the wheelchair on the ground. The platform remains aligned horizontally. When the supports are extended, the wheelchair user deactivates the vehicle unit 11 by a command via the operating unit 35.

The backrest 12b of the wheelchair seat 12 is, as illustrated in FIGS. 1, 8 and 9, attached to the support structure 21. Starting from a rest position, the backrest 12b can be pivoted away from the seat surface 12a about an axis which extends in the transverse direction Q and is arranged in the height direction H below the seat surface 12a. The maximum swivel path from the rest position to a maximum swivel position can be limited by its adjusting device 67. The setting device 67 has, for example, mechanical setting means which define the maximum pivoting path of the backrest 12b. In the exemplary embodiment, the adjustment device for this purpose has adjusting screws 68 which are firmly connected to the backrest 12b and which extend obliquely or, for example, at right angles to the backrest pivot axis R. They are connected to the backrest 12b at a distance from the backrest pivot axis R and, for example, are arranged on brackets. The adjusting screws 68 form a stop to which a counter stop 69 on the support structure 21 is assigned. As soon as the adjusting screws 68 rest against the counter stop 69, the maximum pivoting path of the backrest 12b is reached. If the backrest 12b is relieved, it moves back about its backrest pivot axis R into its rest position. For this purpose, a pretensioning device can be provided, which can be formed, for example, by spring means or other spring-elastic elements.

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LIST OF REFERENCE NUMBERS:

wheelchair

vehicle unit

wheelchair seat

seat

backrest

vehicle drive

wheel

platform

control device

pressure sensor

sensor unit

Steering control element

steering sensor

T rag structure

handle

activation device

pressing part

activation drive

electric motor

screw

Spindle nut guide element

operating unit

support means

front support

rear support

restraint drive

electric motor

screw

Spindle nut flange connection first support part second support part free end of the second support part

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Swivel part spring unit blocking device electric motor threaded spindle spindle nut thrust element rocker arm stop parts stop surface

Spring-damper arrangement

adjustment

adjustment

counterstop

A axis of rotation

BS load position

BZ blocking condition

ES relief position

FZ release status

H height direction

K tilt axis

KS1 first tilt position

KS2 second tilt position

L longitudinal direction

Q transverse direction

R backrest swivel axis

S pivot axis z1 first distance z2 second distance

Claims (16)

1. wheelchair (10), with a vehicle unit (11) which has a control device (16) for controlling a vehicle drive (13) with two drivable wheels (14) arranged at a distance in a transverse direction (Q) and one between the wheels ( 14) arranged platform (15), the platform (15) having pressure sensors (17) which transmit a sensor signal to the control device (16), the control device (16) being set up in the activated state of the vehicle unit (11) to align the platform (15) substantially horizontally and is also set up to deactivate the vehicle drive (13) when the sensor signal from the pressure sensors (17) indicates that the pressure sensors (17) are unloaded, with one between the wheels (14 ) arranged wheelchair seat (12), which is fastened to the platform (15) without acting on the pressure sensors (17), with an electrically controllable support device (38), which has at least one on the front of the vehicle ug unit (11) arranged front support (39) and at least one rear support (40) arranged on the rear of the vehicle unit (11), each of which can be extended and retracted by a separate electrically controllable support drive (41). 2. Wheelchair according to claim 1, characterized in that each prop drive (41) has a self-locking gear. 3. Wheelchair according to claim 1 or 2, characterized in that each support drive (41) has a drivable threaded spindle (43). 4. Wheelchair according to claim 3, characterized in that the threaded spindle (43) is arranged within a cavity of the associated front support (39) or rear support (40). 5. Wheelchair according to one of the preceding claims, characterized in that each front support (39) and each rear support (40) has two telescopically displaceable support parts (46, 47). 6. Wheelchair according to one of the preceding claims, characterized in that each front support (39) and each rear support (40) is pivotally mounted about a respective pivot axis (S) which extends in the transverse direction (Q). 7. Wheelchair according to claim 6, characterized in that each front support (39) and each rear support (40) is acted upon by a spring unit (53) with a restoring moment about the pivot axis (S), which is the front support (39) and the rear support (40) pushes into a starting position. 8. Wheelchair according to claim 6 or 7, characterized in that a blocking device (54) is present which can be switched between a release state (FZ) and a blocking state (BZ), the front support (39) and / or rear support (40) is pivotable about the pivot axis (S) in the release state (FZ) and pivoting about the pivot axis (S) is blocked in the blocking state (BZ). 9. Wheelchair according to claim 8, characterized in that the blocking device (54) has an electrically controllable blocking drive in order to switch the blocking device (54) between the blocked state (BZ) and the released state (FZ). 10. Wheelchair according to claim 8 or 9, characterized in that the blocking device (54) has a movable rocker arm (59) which in the blocking state (BZ) of the blocking device (54) a first 12/22 AT 16 499 U1 2019-11-15 Austrian patent office Tilt position (KS1), in which it provides a stop surface (61) for each stop part (60) of the front support (39) and / or the rear support (40) in order to block the pivoting about the respective pivot axis (S). 11. Wheelchair according to claim 10, characterized in that the rocker arm (59) can only assume the first tilt position (KS1) when the front support (39) and / or the rear support (40) is in their respective starting position. 12. Wheelchair according to claim 10, characterized in that the rocker arm (59) in the release state (FZ) assumes a second rocking position (KS2) in which it engages the stop part (60) of the front support (39) and / or the rear support (40 ) not acted upon during the swiveling movement. 13. Wheelchair according to one of the preceding claims, characterized in that an electrically controllable activation device (25) is provided which has a pressing part (26) which is movable between a relief position (ES) and a loading position (BS) and in the loading position acts on the pressure sensors (17) of the platform (15). 14. Wheelchair according to one of the preceding claims, characterized in that the wheelchair seat (12) is pivotally mounted about a seat axis extending in the transverse direction (Q). 15. Wheelchair according to claim 11, characterized in that the wheelchair seat (12) is supported at a point spaced from the seat axis by a spring-damper arrangement (66). 16. Wheelchair according to one of the preceding claims, characterized in that the wheelchair seat (12) has a spring-pivoting backrest (12b), the maximum pivoting path of which can be adjusted by means of a mechanical adjusting device (67).