Field of the invention

The present invention generally relates to a transforming seat with a lifting mechanism and a vehicle with a transforming seat.

Background of the invention

A number of chairs for vehicles and more specifically for wheelchairs have been developed to lift the user from a sitting position to an eye level position of a standing person. Wheelchairs with an automatic standing aid which can lift and tilt the user into a standing position and also lower the user back into a sitting position are often referred to as stand-up wheelchairs, examples of such devices are described in US5346280A and US6773032B2. One disadvantage of the stand-up wheelchairs is a significant user’s weight transfer in to the lower limbs when the wheelchair is in standing position, the use of such device is complicated for paraplegics and the users who do not have legs. Another disadvantage of the known chairs with lifting and tilting aid is the lack of stability of the user, when the user is in standing position partially supported from the back. One more disadvantage of the stand-up wheelchairs is a complicated management of the centre of gravity, in some cases, management of the centre of gravity is significant, particularly in balancing personal vehicles, wheelchairs stand-up function generally require an additional mechanism to keep the centre of gravity stable in vertical axis. The wheelchairs with an automatic lifting function which can lift the user in a sitting position up and lower down are often referred to as lifting wheelchairs, examples of such devices are described in US20190192362A1, EP3082706B1 and US5209322A. One disadvantage of the lifting wheelchairs is an unnaturally looking high sitting position when the wheelchair is in a lifted position. Another disadvantage of the lifting wheelchair is a significant space requirement in a lifted position.

Summary of invention

An object of the present invention is a vehicle with a transforming seat which overcomes the disadvantages of the prior art devices described above, and which is configured to transform from a sitting position, where the rider is sitting on a relatively flat seat surface like sitting on a chair, to a riding position, where the rider is sitting on a saddle type seat like sitting on a horse or on a bicycle.

The vehicle of the present invention comprises: - a transforming seat configured to support the rider; a base platform configured to support the load including the transforming seat; a locomotion device coupled to the base platform and arranged to propel the vehicle.

Wherein the transforming seat comprises: - a saddle type seat configured to support the rider's pelvis; thigh rests configured to support the rider's thighs; a leg rests mechanism configured to support the rider's feet; a lifting mechanism configured to support the saddle type seat and perform seat transforming as well as lifting and lowering operations.

The transforming seat of the present invention is configured to transform from a first sitting position, where the saddle type seat and thigh rests form a relatively flat and relatively horizontal surface and leg rests are positioned in front of the seat, while the rider's knees and hip joints are bent at approximately 90 degrees, to a second riding position, where the saddle type seat is lifted relatively vertically remaining in a relatively horizontal state, while the thigh rests are inclined downwards in a relation to the saddle type seat, and the leg rests are shifted upwards and backwards and swivelled about an axis approximately perpendicular to the sagittal plane in order to provide the rider with a natural riding posture. Since the saddle type seat remains relatively horizontal during seat transforming operations, the support of the rider's pelvis remains constant, and since there is no tilt of the saddle type seat, no knee supports or additional rider’s body or lower legs immobilization is required. Additionally, when the rider is in a riding position the stability of the rider is increased compared to sitting on a flat seat because of the spatial support of pelvis and thighs.

The thigh rests of the transforming seat are pivotally connected to the saddle type seat in such a manner that allows the thigh rests to pivot from the first relatively horizontal position, where the saddle type seat and the thigh rests form a relatively flat surface, to the second position, where the thigh rests are inclined downwards in a relation to the saddle type seat. Pivoting of the thigh rests can be carried out by actuators or by the system of levers and links, which is operatively connected between said thigh rests and the lifting mechanism. Angle between the saddle type seat and the thigh rests may be adjustable in order to suit the desired angles of the rider's thighs.

The lifting mechanism of the present invention, coupled between a base platform and the saddle type seat, is configured to lift the rider sitting on the saddle type seat to the eye level of a standing person, maintaining parallel and linear, relatively vertical nature of the motion of the saddle type seat, keeping the rider's torso generally upright during lifting and lowering operations and also maintaining relatively linear vertical movement of the rider's centre of gravity.

In the preferred embodiment of the present invention the lifting mechanism is designed as a double parallelogram lifting mechanism, including: a support frame coupled to the base platform, a lower riser, a floating frame, an upper riser and a lifting platform, wherein the lower riser is provided as parallelogram linkage, having at least one main link and at least one support link pivotally connected between the support frame and the floating frame, and an upper riser provided as parallelogram linkage, having at least one main link and at least one support link pivotally connected between the floating frame and the lifting platform, which is configured to carry a payload and to which the saddle type seat is coupled.

The double riser lifting mechanism further includes a synchronization mechanism that is constructed and arranged to maintain angles of the adjacent upper and lower risers, during the lifting and lowering operations of the lifting mechanism. The synchronization mechanism is preferably mounted in the floating frame. In the preferred embodiment of the present invention the synchronization mechanism includes: a pair of interlocking gear segments, the first of which shares a pivot axis with the end of the main link of the lower riser and is rigidly connected to said link, the second one shares a pivot axis with the end of the main link of the upper riser and is rigidly connected to a lever, which is pivotally mounted in said floating frame and shares a pivot axis with said end of the main link of the upper riser, and a compression link which is pivotally connected between said lever and the main link of the upper riser. Preferably, a gear ratio of the interlocking gear segments is 1. The features of this design ensure linear and parallel nature of the lifting platform movement. The lifting mechanism further includes a drive arranged to maintain lifting and lowering operations of the lifting mechanism, wherein the drive of the preferred embodiment of the present invention is operatively connected between the support frame and said lever of the synchronization mechanism. The drive is preferably a linear actuator. The lifting mechanism can further include a resilient member that allows the lifting mechanism to additionally operate as the suspension. In the preferred embodiment of the present invention the compression link of the synchronization mechanism may further be replaced by a coil-over shock absorber or another resilient member to provide more comfortable riding. Resilient member transforms the upper riser of the lifting mechanism in to a trailing arm suspension.

The leg rests mechanism of the present invention can be designed as an independent mechanism or can be interconnected with the lifting mechanism preferably by the system of links and levers. In the preferred embodiment of the present invention the leg rests are pivotally connected to the floating frame of the lifting mechanism, where pivot axis is approximately perpendicular to the sagittal plane, and swivel angle of the leg rests is controlled by linkage pivotally connected between said leg rests and a lever, which is rigidly connected to the toothed lever of the synchronization mechanism forming a bellcrank. Position and pivoting angle of the leg rests may be adjustable in order to suit the desired angles of the rider's lower legs.

The transforming seat may further include a backrest configured to support the rider's back. The backrest is preferably coupled to the saddle type seat and therefore the angle between the backrest and the saddle type seat remains the same during all movements of the transforming seat.

Preferably, the lifting mechanism and seat components are interconnected to achieve the desired rider’s positioning with a minimum number of electro-mechanical components. In the preferred embodiment of the present invention a single linear actuator is used for seat transformation processes.

The locomotion device of the vehicle with a transforming seat can be any device that can propel the vehicle with the rider, including, but not limited to, wheelchair undercarriages, motorized carts, self-balancing undercarriages, tracked undercarriages, propulsion devices having thrust producing units, aircrafts, cars, boats, hovercrafts, and the like and either combination of mentioned devices.

Brief description of the drawings

FIG. 1 is a perspective view of the vehicle with a transforming seat occupied by the rider in the second riding position in accordance with the embodiment, where the locomotion device is a two-wheeled self-balancing undercarriage.

FIG. 2 is a side view of the vehicle with a transforming seat in the first sitting position in accordance with the preferred embodiment.

FIG. 3 is a side view of the vehicle with a transforming seat in the second riding position in accordance with the preferred embodiment.

FIG. 4 is a fragmentary schematic illustration in side view of the transforming seat in accordance with the embodiment with alternative double riser lifting mechanism in the second riding position.

FIG. 5 is a fragmentary schematic illustration in side view of the transforming seat in accordance with the embodiment with alternative scissor lifting mechanism in the second riding position.

FIG. 6 is a fragmentary schematic illustration in side view of the transforming seat in accordance with the embodiment with alternative telescopic lifting mechanism in the second riding position. FIG. 7 is a front view of the vehicle with a transforming seat in accordance with the embodiment, where the lifting mechanism includes a roll pivot.

Detailed description of illustrative embodiments FIG. 1 shows a perspective view of the vehicle with a transforming seat occupied by the rider 1 in the embodiment, where the locomotion device is a self-balancing undercarriage 6, coupled to the base platform 9 and arranged to propel the vehicle, comprising: two wheels 7 that are arranged substantially side-by-side at both sides of the base platform 9 in a direction orthogonal to the traveling direction, electric drives configured to apply torque to the wheels and a controller configured to control the locomotion device and to maintain the balanced state of the vehicle occupied by the rider, where speed and acceleration of the self-balancing locomotion device is controlled by transferring the centre of gravity forward and backward. FIG. 1 also shows planes, which define the orientation of the rider and the transforming seat. The transforming seat in the FIG. 1 is in the second riding position, where the rider on the transforming seat is lifted by the lifting mechanism 5 to the eye level of a standing person, where the pelvis of the rider is supported by a relatively horizontal saddle type seat 2, thighs of the rider are supported by the thigh rests 3, which are inclined downwards in a relation to the saddle type seat 2, while the rider’s feet are supported by the leg rests 4, which are shifted upwards and backwards and swivelled about an axis approximately perpendicular to the sagittal plane in order to provide the rider 1 with a natural riding posture.

FIG. 2 and FIG. 3 show the preferred embodiment of the present invention, where a vehicle with a transforming seat comprises: - a transforming seat configured to support the rider; a base platform 9 configured to support the load including the transforming seat; a self-balancing locomotion device 6 coupled to the base platform 9 and arranged to propel the vehicle.

Wherein the transforming seat comprises: - a saddle type seat 2 configured to support the rider's pelvis; thigh rests 3 configured to support the rider's thighs; a leg rests mechanism 22 configured to support the rider's feet and calves; a lifting mechanism 21 configured to support the saddle type seat and perform seat transforming and lifting- lowering operations.

In the preferred embodiment of the present invention thigh rests 3 are pivotally connected to a saddle type seat 2 in such a manner that pivot axis is approximately perpendicular to the sagittal plane and allows the thigh rests to pivot from a relatively horizontal position as shown in FIG. 2, where the saddle type seat 2 and thigh rests 3 form a relatively flat surface, to a position, where the thigh rests 3 are inclined downwards in a relation to the saddle type seat 2, as shown in FIG. 3. Pivoting of thigh rests is carried out by the system of links 23, which is pivotally attached between said thigh rests 3 and a link 14 of the upper riser 24 of the lifting mechanism 21. Angle between the saddle type seat and thigh rests may be adjusted in order to suit the desired angles of the rider's thighs.

In the preferred embodiment of the present invention a lifting mechanism 21 is provided as an articulated double parallelogram lifting mechanism, including a support frame 10 coupled to the base platform 9, a lower riser 27 provided as parallelogram linkage, having a main link 12 and a support link 11 pivotally connected between a support frame 10 and a floating frame 15, and an upper riser 24 provided as parallelogram linkage, having a main link 14 and a support link 13 pivotally connected between the floating frame 15 and a lifting platform 16. Preferably, the ends of the support links 11 and 13 of the upper and lower risers, which are pivotally connected to the floating frame 15, share the same pivot connection 28.

In the preferred embodiment of the present invention the lifting mechanism includes a synchronization mechanism 17 mounted in the floating frame and comprises: a pair of interlocking gear segments, the first of which 18 shares a pivot axis 29 with the end of the main link 12 of the lower riser 27 and is rigidly connected to said link, the second one 19 shares a pivot axis 30 with the end of the main link 14 of the upper riser 24 and is rigidly connected to a lever 33, which is pivotally mounted in said floating frame and shares a pivot axis 30 with the end of the main link 14 of the upper riser 24, and a compression link 35 which is pivotally attached between said lever 33 and the main link 14 of the upper riser 24. Preferably, a gear ratio of the interlocking gear segments is 1. In the preferred embodiment of the present invention the compression link 35 of the synchronization mechanism 17 is an air shock absorber, which transforms the upper riser 24 of the lifting mechanism 21 in to a trailing arm suspension in order to provide more comfortable riding. In some embodiments, compression link 35 of the synchronization mechanism 17 can be replaced by a coil-over shock absorber or any other resilient member.

In the preferred embodiment of the present invention the lifting mechanism further includes a drive, which is a linear actuator 38, operatively connected between the support frame 10 and the lever 33 of the synchronization mechanism 17.

In the preferred embodiment of the present invention the transforming seat further comprises a leg rests mechanism 22, which includes leg rests 4, configured to support the rider's feet and calves. The leg rests mechanism is designed in a manner that allows the leg rests 4 to move from the first sitting position, where leg rests 4 are positioned in front of the saddle type seat 2 as shown in FIG. 2, while the rider's knees and hip joints are bent at approximately 90 degrees, to the second riding position, where the leg rests 4 are moved upwards and backwards and swivelled about a pivot axis 25, which is approximately perpendicular to the sagittal plane, such that to provide the rider with a natural riding posture, as shown in FIG. 3. In the preferred embodiment of the present invention the leg rests mechanism is interconnected with the lifting mechanism, where the leg rests 4 are pivotally connected to a floating frame 15 of the lifting mechanism, a pivot axis 25 is approximately perpendicular to the sagittal plane and swivel angle of the leg rests 4 is controlled by the linkage 26 pivotally connected between said leg rests and a lever 36, which is rigidly connected to the toothed lever 33 of the synchronization mechanism 17 forming a bellcrank.

In the preferred embodiment of the present invention components of the transforming seat are interconnected to achieve the desired rider’s positioning with a minimum number of electro-mechanical components. A single linear actuator 38 is used to perform seat transforming and lifting- lowering operations. In some embodiments, pivoting of thigh rests can be carried out by the actuators or system of links 23, operatively connected between said thigh rests 3 and the lifting mechanism 21, 50, 60. Angle between the saddle type seat 2 and thigh rests 3 may be adjustable in order to suit the desired angles of the rider's thighs.

In some embodiments, a leg rests mechanism can be designed as an independent mechanism or can be interconnected with the lifting mechanism by the system of links and levers, examples of such systems 72, 63, 53 are shown in FIG. 4, FIG. 5 and FIG. 6. The leg rests 4 can be interconnected with the lifting mechanism by the system of links 51, 52, as shown in FIG. 5 and FIG. 6, to provide vertical and horizontal components of motion of the leg rests, while pivoting of the leg rests 4 about pivot axis 25 can be carried out by actuators (not shown) or by the links 26 pivotally attached between said leg rests 4 and link 51 of said system of links. Position and pivoting angle of the leg rests may be adjustable in order to suit the desired angles of the rider's lower legs.

In some embodiments, the transforming seat can include a resilient member that is incorporated in the lifting mechanism and allows the lifting mechanism to additionally operate as the suspension. In some embodiments, the resilient member can be incorporated in the drive of the lifting mechanism.

In embodiments with double parallelogram lifting mechanism, the lifting mechanism can include a synchronization mechanism preferably mounted in the floating frame. In some embodiments, the synchronization mechanism can be provided as a system of links and levers, or as a pair of interlocking gear segments or other known in the art systems.

In some embodiments, the lifting mechanism can include at least one drive that can be hydraulic, electric, pneumatic, or similar drive, which is operatively connected to the lifting mechanism and is capable to perform seat transforming and lifting- lowering operations. In some embodiments, where the locomotion device of the vehicle with a transforming seat is a military vehicle, the drive of the lifting mechanism can be designed as an impact absorbing member. In some embodiments, the lifting mechanism can be any known in art lifting mechanism that is capable to perform relatively parallel and linear lifting and lowering operations, including, but not limited to, a scissor lifting mechanism, example of scissor lifting mechanism 50 is shown in FIG. 5, or telescopic lifting mechanism, example of telescopic lifting mechanism 60 is shown in FIG. 6, or double riser lifting mechanism, example of double riser lifting mechanism 70 is shown in FIG. 4, where the lifting and lowering operations are performed via separately controlled electric motors operatively connected at the pivot points 71 of the lifting mechanism 70. In some embodiments, the locomotion device of the vehicle with a transforming seat can be any device that can propel the vehicle and the rider, including, but not limited to, wheelchair undercarriages, motorized carts, self-balancing undercarriages, tracked undercarriages, propulsion devices having thrust producing units, aircrafts, cars, boats, hovercrafts, and the like and either combination of mentioned devices.

In the embodiment, where the locomotion device is a self-balancing locomotion device 6, which is unstable for tipping, when at rest on the surface and the power or balance mode is switched off, the vehicle with a transforming seat further includes retractable anti tipping legs for anti-tipping support of the vehicle. The example of the anti-tipping legs 37, in retracted position, is shown in FIG. 2 and the example of the anti-tipping legs 37, in extracted position, is shown in FIG. 3.

In some embodiments, the conventional occupation sensors can be used to detect when the rider gets on or off the vehicle. The occupation sensors can be positioned in the seat or in the feet rest, or at other appropriate locations.

In some embodiments, the transforming seat may further include a backrest configured to support the rider's back. The backrest 8 is preferably coupled to the saddle type seat 2 and therefore the angle between the backrest and the saddle type seat remains the same during all movements of the transforming seat.

In some embodiments of the vehicle with a transforming seat, the lifting mechanism is coupled to the base platform 9 via a roll pivot 82, where pivot axis is relatively perpendicular to the frontal plane, and allows the lifting mechanism to tilt in frontal plane, in relation to the pivot support frame 81, which is coupled to the base platform 9, as shown in FIG. 7. Pivoting of the lifting mechanism in relation to the base platform can be carried out by the drives, preferably linear actuators. Said pivoting of the lifting mechanism can be controlled by the inputs from the gyroscopes, inclinometers, and force sensors or similar in order to increase the rollover resistance of the vehicle with transforming seat, when moving on an uneven surface, slopes or when cornering.

In some embodiments, the saddle type seat 2 is mounted on the lifting platform 16, 55, 65 by using the slide rails to allow fine adjustment of the position of centre of gravity by selectively moving said saddle type seat forward and backward in sagittal plane. Control of said movement can be carried out by an electrical or manual linear actuator connected between said lifting platform and said saddle type seat.

In some embodiments, the transforming seat of the present invention can’t include thigh rests 3 or leg rests 4.

In some embodiments, where the locomotion device of the vehicle with a transforming seat is the propulsion device having thrust producing units coupled to the platform on which the rider is standing, the transforming seat can significantly reduce the load transfer in to the rider’s lower limbs.

A number of embodiments of this invention were described above, although various other modifications and configurations may become apparent to those skilled in the art, thereby this invention is not limited by the above written embodiments, but within the scope of the appended claims.