TWI798223B - Motor-driven chair steered by seat rotation - Google Patents

Abstract

A motor-driven chair has a central drive wheel located beneath the seat and linked so as to be aligned with the facing direction of the seat. A user turns the direction of motion by rotating the seat relative to a surrounding stabilizer assembly so as to turn the seat and the drive wheel towards a direction in which he wishes to move. A suspension arrangement maintains a desired distribution of user load between the drive wheel and the stabilizer assembly. A combination of fixed-axis wheels with castered wheels provides angular anchoring of the stabilizer assembly to facilitate the seat steering process. The entire structure is preferably foldable for easy transportation and storage.

Description

Electric chair with seat swivel operation

The present invention relates to various mobility aids, and in particular to electric chairs which are operated by rotation of the seat.

It is known that a wide range of mobility aids are offered for individuals with various levels of limitation. Of particular relevance to the present invention is a class of mobility aids referred to herein as seat-operated motorized seats, as exemplified in U.S. Patent No. 5,183,133, in which a centrally driven The wheels are connected so as to be aligned with the facing direction of the seat. The user steers the direction of motion by rotating her seat relative to the nearby stable base so as to face the direction her lock wishes to move.

The invention is an electric chair operated by seat rotation.

According to the teachings of one embodiment of the present invention, there is provided a power chair for propelling a user over a lower surface, the power chair comprising: (a) a seat element having support surfaces for supporting the user seated in a seat facing direction; (b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel , relatively rotatable about a horizontal axis of rotation to define a forward direction of motion perpendicular to the axis of rotation, the drive wheel is mechanically connected to the seat post, the drive wheel is mechanically connected to the seat post to maintain the forward direction of motion right aligning the seat-facing direction so that rotation of the seat element relative to the vertical axis causes a corresponding rotation in the forward direction of motion; (d) a motor, drivingly connected with the drive wheel, to drive the drive wheel rotates relative to the horizontal axis of rotation, thereby propelling the electric chair in the seat-facing direction; (e) a stabilizer assembly, mechanically connected to the seat post, comprising a set of stabilizer wheels mounted on a a support structure for supporting the seat post in a vertical direction, the stabilizer assembly allowing the seat post to rotate about the vertical axis relative to the support structure; The drive wheel and the stabilizer assembly are coupled, and the suspension arrangement is configured to spread a load of the user seated stably on the seat element so as to maintain a load supported by the drive wheel and the stabilizer assemblies. A predefined proportional range between a load supported by the wheel.

According to another feature in an embodiment of the present invention, the suspension means is configured to distribute the load of the user seated stably on the seat element such that a substantially constant proportion of the user's body weight passes through The drive wheels support and the user's weight is supported by the stabilizer wheels within a remaining proportion of the user's weight in any range between 50 kg and 100 kg, the substantially constant proportion being the Between 30% and 90% of the user's body weight.

According to another feature of an embodiment of the invention, the suspension arrangement comprises a first suspension spring arrangement for transmitting a load between the seatpost and the drive wheel and a second suspension spring, arranged for transferring a load transferred between the seat post and the support structure.

According to another feature of an embodiment of the invention, the suspension device comprises a first hydraulic device comprising at least one piston and a second hydraulic device, the first hydraulic device being arranged to transmit a load between the seat post and the drive wheel, and the second hydraulic device comprising at least one piston, the second hydraulic device being arranged to transmit a load between the seat post and the support structure, wherein The first hydraulic device and the second hydraulic device are connected to each other through a pressure balance pipeline.

There is also provided a power chair for propelling a user over a lower surface according to the teachings of one embodiment of the invention, the power chair comprising: (a) a seat element having support surfaces for supporting the user seated in a seat facing direction; (b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel , relatively rotatable about a horizontal axis of rotation to define a forward direction of motion perpendicular to the axis of rotation, the drive wheel is mechanically connected to the seat post, the drive wheel is mechanically connected to the seat post to maintain the forward direction of motion Aligning the seat-facing direction such that rotation of the seat element relative to the vertical axis causes the forward movement a corresponding rotation in the direction; (d) a motor, which forms a driving connection with the drive wheel to drive the drive wheel to rotate relative to the horizontal axis of rotation so as to propel the electric chair in the seat-facing direction; (e) a stabilizer assembly mechanically coupled to the seatpost, the stabilizer assembly comprising a set of stabilizer wheels mounted on a support structure for supporting the seatpost in a vertical orientation, the stabilizer assembly allowing the The seat post rotates about the vertical axis relative to the support structure, wherein the set of stabilizer wheels includes the set of stabilizer wheels including at least one fixed axle driven wheel and at least one caster wheel mounted for rotation to adjust the steering of the electric chair.

According to another feature of an embodiment of the present invention, the set of stabilizer wheels includes at least two fixed axle driven wheels and at least two caster wheels mounted for rotation to adjust the steering of the electric chair.

There is also provided a power chair for propelling a user over a lower surface according to the teachings of one embodiment of the invention, the power chair comprising: (a) a seat element having support surfaces for supporting the user seated in a seat facing direction; (b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel , relatively rotatable about a horizontal axis of rotation to define a forward direction of motion perpendicular to the axis of rotation, the drive wheel is mechanically connected to the seat post, the drive wheel is mechanically connected to the seat post to maintain the forward direction of motion aligning the seat-facing direction so that rotation of the seat element relative to the vertical axis causes a corresponding rotation in the forward direction of motion; (d) a motor, drivingly connected with the drive wheel, to drive the drive wheel The wheel rotates relative to the horizontal axis of rotation, thereby propelling the electric chair along the seat-facing direction; (e) a stabilizer assembly, mechanically connected to the seat post, comprising a set of several stabilizer wheels mounted on on a support structure for supporting the seat post in a vertical orientation, the stabilizer assembly permits rotation of the seat post about the vertical axis relative to the support structure, wherein the support structure includes: a central portion mechanically connected to to the seatpost; a front, hingedly connected to the center portion at a first hinge axis and supporting the two front wheels in the set of stabilizer wheels; and a rear, hingedly connected at a second hinge axis to the central portion and supports the two rear wheels of the set of stabilizer wheels, wherein the first and second articulation axes are axes parallel to each other.

According to another feature of an embodiment of the invention, the two front wheels are two castor wheels foldably mounted to the front by means of folding wings along a secondary hinge axis which is not parallel to the first hinge axis, the support structure further comprising a link arranged to fold the folded wings from an unfolded position to a folded position when the front portion is rotated relative to the first hinge axis .

There is also provided a power chair for propelling a user over a lower surface according to the teachings of one embodiment of the invention, the power chair comprising: (a) a seat element having support surfaces for supporting the user seated in a seat facing direction; (b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel , relatively rotatable about a horizontal axis of rotation to define a forward direction of motion perpendicular to the axis of rotation, the drive wheel is mechanically connected to the seat post, the drive wheel is mechanically connected to the seat post to maintain the forward direction of motion aligning the seat-facing direction so that rotation of the seat element relative to the vertical axis causes a corresponding rotation in the forward direction of motion; (d) a motor, drivingly connected with the drive wheel, to drive the drive wheel The wheel rotates relative to the horizontal axis of rotation, thereby propelling the electric chair along the seat-facing direction; (e) a stabilizer assembly, mechanically connected to the seat post, comprising a set of several stabilizer wheels mounted on on a support structure for supporting the seat post in a vertical direction, the stabilizer assembly allowing the seat post to rotate about the vertical axis relative to the support structure; and (f) a height adjustment mechanism associated with the seat post integrally formed and arranged for adjusting a height of the seat element above the lower surface between a lowered position for mounting and removal and a raised position for driving.

According to another feature of an embodiment of the present invention, a footrest is provided, mechanically connected to the height adjustment mechanism, to move perpendicularly to the seat element so as to be moved in the lowered position of the seat element. Bringed into contact with the lower surface and lifted away from the lower surface in the raised position of the seat element, the seat element is rotatable relative to the vertical axis independently of the footrest.

According to another feature of an embodiment of the invention, the stabilizer assembly is a collapsible stabilizer assembly foldable from an unfolded state for supporting the power chair to a folded state for compact storage and transport, and Wherein the footrest is mechanically connected to the stabilizer assembly so as to block the stabilizer assembly from collapsing from the unfolded state to the folded state when the footrest is in the raised position.

According to another feature of an embodiment of the present invention, wherein the footrest has a foot support surface, the foot support surface includes: a rear portion, adjacent to the seat element; and a front portion, protruding away from the seat element, The front portion and the rear portion are connected in a hinged manner to allow inward folding of the front portion of the foot support surface.

According to another feature of an embodiment of the present invention, the stabilizer assembly is a collapsible stabilizer assembly that can be folded from an unfolded state for supporting the power chair to for compact storage and In a folded state for transport, the power chair also includes a fold assist mechanism for assisting in the folding of the stabilizer assembly, the fold assist mechanism includes a spring loaded actuator associated with the height adjustment mechanism is coupled, and deployed such that the seat element is lowered from the raised position to the lowered position, causing the actuator to come into engagement with a portion of the stabilizer assembly, and to apply a load to an inner spring of the actuator, The load is relieved during at least part of a folding movement of the stabilizer assembly.

10: Electric chair

12: Seat element

14: Support surface

16: Support surface

18: Seat post

F: Forward movement direction

20: vertical axis

22: Drive wheel

24: Stabilizer assembly

26: Stabilizer wheel

28: Stabilizer wheel

30: Center part

32: front frame

34: rear frame

36: The first helical compression spring

38: Second helical compression spring

40: folding arm

42: central part

44: Piston

46:piston

48: Pressure balance pipeline

50: suspension element

52: hydraulic cylinder

54: pipeline

56: Armrest

58: First hinge axis

60:Second hinge axis

62: Folding Wings

64: Auxiliary hinge axis

66: Rod

68: slide

70: connecting rod

72: Partial gear structure

74: Partial gear structure

76: Adjacent surfaces

78:Mechanical stopper structure

100: chair

102: Pedal

104: Transmission unit

106: Bracket

108: support arm

110: upper column housing

112: notch

114: front

116: hinged connection

118: Folding auxiliary mechanism

120: Internal spring

122: rocker switch

124: handle

126: flexible element

128: cross bar

The present invention is described herein by way of example only with reference to the accompanying drawings, in which: Figures 1A and 1B show a perspective view of a power chair configured and operative in accordance with one embodiment of the invention; A vertical cross-sectional view taken in a mid-plane of the power chair of FIG. 1A; FIG. 2B shows an enlarged view of the lower area of FIG. 2A; FIG. 3A to FIG. A series of isometric views of the series of operations of the electric chair; Figures 4A and 4B show enlarged views of the circled areas in Figures 3C and 3D, respectively; Figure 5 shows Figure 1A in A schematic top view of a series of positions of the electric chair during rotation; Fig. 6 shows a sectional isometric view of a suspension device of an electric chair according to a variant embodiment of the present invention; Figure 7B shows an enlarged view of the area marked with an ellipse in Figure 7A; Figure 8A shows a view similar to Figure 2B, showing a variant embodiment of a stabilizer assembly with several interlocking configurations, shown in a deployed state; Figure 8B Figure 8A shows an enlarged view of an area indicated by a dotted ellipse; Figures 9A and 9B show views similar to Figures 8A and 8B, respectively, showing the stabilizer in a folded state Components; Fig. 10 shows another embodiment of the present invention adopts a perspective schematic diagram of an electric chair with a hydraulic suspension device; Fig. 11A shows an isometric sectional view of the electric chair in Fig. 10 along a vertical median plane; Fig. 11A Figure 11B shows an enlarged view of the area indicated by an ellipse in Figure 11A; Figure 12 shows a partial isometric cross-sectional view of a variant embodiment of an electric chair according to the invention, showing a suspension device An alternative embodiment; Figure 13 shows an isometric view of another variant embodiment of an electric chair according to the present invention, showing another embodiment of a suspension device; Figures 14A and 14B show Figure 15A and Figure 15B show the rear isometric view of the power chair shown in Figure 14A, respectively, to illustrate the configuration and operation of another embodiment of the present invention, respectively, in the unfolded and folded states; Front isometric views of seat raised and lowered states; Figures 16A to 16C show side views of the power chair of Figure 14A, respectively, showing a seat raised state and a seat lowered state state and a folded state; Figure 17A shows an isometric view cut along a symmetrical central plane when the electric chair of Figure 14A is in a raised state; Fig. 17B and Fig. 17C respectively show the electric chair of Fig. 14A respectively in a seat raising state and a seat descending state, cut along a symmetrical central plane; Fig. 18A shows Figure 18B shows an enlarged view of an area of Figure 17B indicated by dashed line A; Figure 18B shows a view of an area of Figure 18A indicated by dashed line B showing the seat down and a stabilizer assembly folded and Figures 19A to 19F show a sequence of isometric views of the power chair of Figure 14A, showing one of a series of folding the power chair from a fully open seat down condition to a fully folded condition; order.

The invention is an electric chair operated by seat rotation.

The principles and operation of a power chair according to the present invention may be better understood with reference to the drawings and accompanying descriptions.

Referring now to the drawings, FIGS. 1A through 13 illustrate various embodiments and variant embodiments of a power chair, herein designated 10, for propelling a user on an underlying surface. In general, the power chair 10 has a seat element 12 with support surfaces 14, 16 for supporting the user while sitting in a "seat-facing orientation". A post 18 extends downwardly from the seat element 12 to support the seat element. Seatpost 18 may define a vertical axis 20 . A drive wheel 22 is relatively rotatable about a horizontal axis of rotation to define a direction of forward movement F perpendicular to the axis of rotation, with the seat element 12 lying substantially on the vertical axis 20 . The drive wheel 22 is mechanically connected to the seatpost 18 so that the direction of forward movement F is aligned with the seat-facing direction of the seat element 12 so that rotation of the seat element relative to the vertical axis 20 produces the forward movement Corresponding rotation in direction F.

A motor, typically implemented as a hub motor within the drive wheel 22, is drivingly connected to the drive wheel 22 (not shown in detail here) to drive the drive wheel 22 in rotation relative to a horizontal axis of rotation so that the electric chair moves along the Push toward the seat. To maintain the stability of the powered chair 10 , a stabilizer assembly 24 is mechanically connected to the seatpost 18 . The stabilizer assembly 24 includes a set of several stabilizer wheels 26, 28 is carried on a support structure, here formed by a central portion 30 coupled to a front frame 32 and a rear frame 34, to support the seatpost 18 in a vertical orientation. Stabilizer assembly 24 is configured to allow rotation of seatpost 18 relative to vertical axis 20 relative to the support structure.

In this context, the various aspects of the invention provide some particularly advantageous features with respect to the implementation of the electric chair 10 . Specifically, according to a first non-limiting combination of particularly preferred embodiments of the present invention, the power chair 10 is provided with a suspension device coupled to the seatpost 18, the drive wheels 22 and the stabilizer assembly 24 for stably sitting on the chair. A load of a user on the seat element 12 is distributed to distribute the load supported by the drive wheels 22 and the stabilizer assembly 24 in proportion as desired. In particular, the embodiment of the suspension is preferably such that the load both on the stabilizer assembly and on the drive wheel varies in relation to the weight supported by the seat element 12 .

The significance of this feature can best be understood by contrasting with (eg US Patent No. 5,183,133) some prior arrangements of the center drive wheel, seat steered type, where a spring biases the outrigger frame downward with a fixed force , while all remaining loads are applied rigidly to the drive wheel. This configuration results in extreme variations in the load applied to the drive wheels, which can lead to loss of traction of the device at small loads and instability at high loads.

Conversely, according to the first aspect of some particularly preferred embodiments of the present invention, the suspension linkage is configured to stably distribute a load of a user sitting on the seat element 12 down through the seat. rod 18 to distribute the load between drive wheels 22 and stabilizer assembly 24 according to the desired ratio. Specifically, an alternative to a load on the stabilizer assembly 24 (or alternatively, on the drive wheels 22) is a fixed load that increases, preferably monotonically, with a load increasing function at each, preferably It is intended that the device satisfies the entire range of normal body weight, for example between at least 50 kg and 100 kg, and in some cases a range of at least 30 kg and 150 kg.

According to a first embodiment of a particularly preferred group of embodiments, the aforementioned suspension arrangement is implemented using a first spring arrangement to transfer the load from the seatpost 18 to the drive wheel 22, and a second spring arrangement to transfer the load from the seatpost 18 Passed to the stabilizer assembly 24. In the first embodiment in FIG. 2B , the first spring means is embodied as a first helical compression spring 36 and the second spring means is embodied as a second helical compression spring 38 . In the case shown here, the compression spring 36 is arranged in an inner channel and the compression spring 38 is arranged in an annular channel surrounding the inner channel. Another functionally equivalent suspension arrangement with similar numbers is shown in Figure 6, where the components are more visually clear. (this match 2B, except that the stabilizer assembly 24 is realized in a different way, with several folded arms 40 protruding radially relative to a central portion 42 (here embodied as a cylinder), each folded Arm 40 supports a caster 26).

In the above-described embodiment, the subdivision of the load on the seat between the drive wheel and the stabilizer assembly is based on the relative spring constants of the two spring devices, according to their respective load states in their initial positions. Adjust for any initial offset between (i.e. not the same preload). In the absence of any offset, the proportion of load transmitted to the drive wheel and the stabilizer assembly remains approximately constant as the load varies. If an offset exists, the ratio can vary, but in each case the load on the drive wheel and stabilizer assembly increases monotonically as a load increasing function, thereby maintaining the weight distribution at Within predetermined limits, to ensure reliable driving with the ground and structural stability, while being used for a wide range of user volumes. In a most particularly preferred embodiment, the load distribution on the seat remains within the range of 30% to 90% of the user's body weight on the drive wheels, and the remainder of the body weight is transferred through the stabilizer assembly.

Reference is now made to Figures 10-11B which illustrate an alternative embodiment according to an aspect of the present invention in which the suspension comprises a first hydraulic device having at least one piston 44 configured to The load is transferred between the seat post 18 and the drive wheels 22 , and a second hydraulic device, having at least one piston 46 , is configured to transfer the load between the seat post 18 and the stabilizer assembly 24 . The first hydraulic device and the second hydraulic device are connected to each other through a pressure balance line 48 . Since the pressure on the two pistons is equalized through line 48, the force (load) transmitted to drive wheel 22 and stabilizer assembly 24 is proportional to the surface area of the pistons, thereby subdividing the load into a predetermined desired ratio, as discussed above.

In the particularly straightforward embodiment shown here, the piston 46 is realized as an annular piston slidingly engaged about a central axis of the seatpost 18 through which the pressure equalization line 48 passes. It should be understood that alternative embodiments may employ more known hydraulic actuator configurations such as side-by-side cylinder/piston, optionally with several smaller cylinders arranged around a central large cylinder, all of which It is clear and understandable to those who are familiar with the art in the technology of hydraulic systems.

Furthermore, although a different structural embodiment is only shown schematically in this context (shown only schematically here), it should be noted that the hydraulic suspension can alternatively also easily be structurally (in all other respects) a device similar to the embodiment of Figures 1 to 5 Therefore, this feature can be combined with a series of other features described in the present invention with respect to the embodiments.

The term "hydraulic" as used in this specification and claims refers to any system or component operated by fluid pressure, whether by liquid or gas (the latter also referred to as "pneumatic"). Thus, the hydraulic implementation options described herein may be implemented using an incompressible hydraulic fluid such as water or oil, or using a compressible fluid such as air or another gas or gas mixture. In the case of pneumatic systems, it may be advantageous to provide a pre-charged starting pressure within the hydraulic system.

Turning now to Figures 12 and 13, although the embodiment of the suspension described so far distributes the load centrally to the stabilizer assembly 24, in some cases it may be preferable to Wheels or several subassemblies of these stabilizer wheels provide individually responsible suspension units. These options are shown schematically in Figures 12 and 13.

Specifically, Figure 12 shows an embodiment generally similar to that of Figure 6, in which several elements of the stabilizer assembly 24 are interconnected so as to be rotatable relative to the seat post 18 while rigidly placing the vertical load Several elements passed to the stabilizer assembly 24 . Separate spring suspension elements 50 are integrally formed with each stabilizer wheel 26 , operating in parallel with the springs 36 to distribute the load applied between the drive wheel 22 and the stabilizer wheel 26 .

Figure 13 shows a conceptually similar hydraulic implementation in which separate hydraulic cylinders 52 are configured to transfer load from elements of the stabilizer assembly 24 to the stabilizer wheels 26, the hydraulic cylinders 52 is parallel to the central hydraulic cylinder/piston arrangement 44 which transmits the load to the drive wheels 22 . A set of pressure equalization connectors, shown schematically here as lines 54 , ensures pressure equalization between the hydraulic cylinders 52 and the central hydraulic cylinder 44 . As previously stated, the distribution of load among the wheels is proportional to the surface area of the various pistons, thereby subdividing the load among the various wheels in a predetermined ratio.

In all of the above discussions regarding the several embodiments of the suspension, the subdivision of the load described relates to the distribution of a load applied vertically downwards on the seat element 12 and transmitted axially downwards along the seat post 18 . This is generally the case for a user sitting stably on the seat element 12, where the user's center of gravity is generally located in the area of the seat, usually within about 30 cm from the vertical axis 20, and thus mainly downwards. effect. It should be clear that the normal distribution of the load may be briefly interrupted when the power chair 10 is installed or removed or in the event of externally applied forces. Other preferred features below The stability of the device during installation or removal will be described with reference to the embodiments of Figures 14A to 19F.

Turning now to another aspect of certain particularly preferred embodiments of the present invention, the present invention provides a power chair that is manipulated by rotation of the seat such that the forward direction F of the drive wheel 22 is always aligned with the direction F of the seat element 12. The forward direction is aligned, and the user changes direction by turning her seat in the direction she wishes to move. To date, devices of this type have been designed with omnidirectional "outrigger" or stabilizer structures, meaning that the user can turn in any direction and start moving in a straight line in that direction, and A set of casters around the stabilizer structure will immediately align with this new orientation.

While providing very high mobility, it has been found that there are certain problems with the use of omnidirectional stabilizer structures. Specifically, in order to change the orientation of the seat and thus the drive wheels 22, the user must apply a considerable torque relative to the vertical axis 20 to overcome the friction between the drive wheels 22 and the underlying surface. Such a rotational moment is preferably achieved by the user applying a lateral force to the stabilizer structure with his foot. However, it has been found that such lateral forces may sometimes have the undesired effect of turning the stabilizing structure relative to the drive wheels instead of turning the drive wheels.

In order to solve this problem, some particularly preferred embodiments of the present invention, such as the embodiments shown in Figs. To adjust the steering of the electric chair. In the particularly preferred embodiment shown here, the electric chair 10 has at least two fixed axle driven wheels 28 , here carried by a rear frame 34 , and at least two castor wheels 26 , here carried by a front frame 32 . The fixed axle stabilizer wheels 28 are inherently non-tangentially aligned relative to the seat post 18 and are therefore very effective at preventing rotation of the stabilizing structure relative to the drive wheels. Thus, a rotational moment applied to the stabilizer structure by the user's foot reliably achieves the desired result of turning the seat and the drive wheel.

The motion resulting from such a structure is shown schematically in Figure 5, where the solid line P marks the path of the central axis 20 during a turn. In position A, the power chair aligns the seat and travels in a straight line from left to right as shown. In position B, the user chooses to turn to her right by applying a leftward force with her foot to the front frame 32, thus turning the seat and thus also turning the forward direction of the drive wheel to the right. Since the fixed axle wheels 28 are now not facing in the same direction as the seat is facing and cannot advance in the new forward direction of the drive wheel, the fixed axle Wheel 28 outlines a circular path. Therefore, as the movement continues, the rear frame 34 The fixed-axis driven wheel 28 outlines a circular trajectory relative to a rotation center O, and the rotation trajectory defines the intersection point of the rotation axis direction of the driving wheel and the fixed-axis wheel. Each of the castors 26 also aligns themselves with their corresponding circular path according to their distance from the center O. This circular motion continues (eg, through position C) as long as the user maintains the sideways position of the seat. At any point where the user chooses to return the seat to a symmetrical position relative to the front and rear frames, the fixed axle wheels will drop behind the seat and return to a straight path, as shown in position D. Although a sudden change in seat orientation is shown schematically here as occurring at positions B and D, in most cases the steering adjustment will be implemented smoothly, resulting in a smooth change in orientation. But the principle of operation remains the same.

Turning now to yet another aspect of the present invention, it is a preferred feature of certain embodiments of the present invention that the power chair 10 is implemented to be collapsible for ease of transport and storage. Specifically, the seat pivoting structure of the present invention is essentially a single post structure, wherein the load on the seat is transmitted through a single seatpost 18, making the core of the support structure relatively simple. However, in order for the power chair 10 to remain stable under normal conditions of use, it is necessary to provide considerable spread between the various stabilizer wheels 26 . Certain preferred embodiments of the present invention provide simple and effective folding mechanisms that allow the device to be easily folded and unfolded, and provide a compact form for easy transport and storage.

According to various aspects of the folding mechanism according to a preferred embodiment of the present invention, Figures 3A to 3D show sequential folding schematic views and Figures 4A to 4B show enlarged views. First, the seat element 12 is primarily foldable, for example by folding the rear support surface 16 and (if present) the armrest 56 down against the support surface 14 (Fig. 3A), and then preferably with the entire seat element 12 pivots so as to pour into close relationship with seat post 18 (FIG. 3B).

The support structure (stabilizer assembly 24) folds here by providing a central portion 30, mechanically connected to the seat post 18; central part 30 and supports two front stabilizer wheels 26; A hinge axis 58 and a second hinge axis 60 are preferably axes parallel to each other to facilitate folding the front frame 32 and rear frame 34 into close proximity.

According to another preferred feature shown here, the castors 26 are foldably mounted to the front frame 32 by means of folding wings 62 along a secondary hinge axis 64 which is not parallel to the hinge axis 58 , and in this case substantially perpendicular to the axis of articulation 58 . for To simplify the unfolding and folding of the wings 62, the stabilizer assembly 24 preferably includes a linkage arranged to move the folded wings 62 from a deployed position when the front frame 32 is rotated relative to the hinge 58. Fold to a folded position (FIGS. 4A and 4B). In the non-limiting embodiment shown here, the linkage of each wing 62 employs a bar 66 to be hingedly attached to the center section 30 at an offset from the hinge 58 and connected to the front frame along the front frame. 32 side rail slides a slider 68, and a connecting rod 70 is connected to the slider 68 and the wing 62 through a pivotal connection. Because of this construction, the downward movement of the front frame 32 and rear frame 34 from their fully raised operating position towards the folded position causes the rod 66 to pull the slider 68 along the side rails of the front frame 32 in the direction of the hinge 58, thereby also pulling the connection. lever 70 to fold the wings 62 inwardly to the folded position of Figure 4B. Conversely, when the front frame 32 is opened to its deployed state, the movement is reversed and the wings 62 are pushed outward to their deployed state, ready for use. Thus, this mechanism provides an improved lateral wheelbase for the stabilizer assembly 24 while achieving a highly compact folded condition.

In the embodiment shown here, these folding wing features are only used for the front frame 32, while the rear frame 34 has a fixed geometry. A variant embodiment described below (see Figures 14A to 19F) employs several folding wings 62 on both the front and rear frames.

Figures 8A to 9B illustrate another option, a mechanical linkage coordinating the folding of the front frame 32 and rear frame 34 . In the embodiment shown here, each frame is provided with a portion of gear formations 72 and 74 which are centered on the respective axes 58 and 60 and which intermesh to ensure that the two frames are in their respective positions. Equal and opposite rotations between the unfolded state (FIGS. 8A and 8B) and its fully collapsed state (FIGS. 9A and 9B). The gear arrangement shown also includes a number of abutment surfaces 76 which define the fully raised deployed position of the frames. This partially geared form is one of many different forms of mechanical linkage that can be used to coordinate front and rear frame folding, with a range of additional options within the purview of those skilled in the art.

Turning now to the remaining features of the powered chair 10, the device also includes a mobile power source, usually in the form of one or more rechargeable batteries, which may advantageously be housed in a volume beneath the seat support surface 14, or alternatively located in a stable The central part of the device assembly 24. A forward/reverse speed control input (not shown) is provided to the user, usually integrally formed with an armrest 56, or as a separate hand-held controller which may be connected by a cable to the side of the seat. The wiring between the battery, controller and drive motor typically runs along a cable channel through the seat post 18 . For some applications, simple electrical control of the current to the motor is essential for a practical is enough. Optionally, an electronic controller may be used with various additional functions, for example, providing monitoring of battery state of charge and battery health, monitoring and limiting the speed of motion on the motor and/or load. Implementation of all such options is a matter of course for those skilled in the art, and for the sake of brevity, these details will not be discussed further herein.

Most preferably, a stopper arrangement is provided on one or more wheels of the device to provide stability and safety when the device is stopped, particularly during installation or removal. As shown in FIGS. 2B and 7A , the embodiment shown here provides a mechanical stop structure 78 , typically a friction stop, which acts on the drive wheel 22 . The stopper is preferably manually operated by an actuator cable (not shown) that passes up to a handle (not shown) on the side of the seat. Alternatively, a foot stop may be provided on the drive wheel or on one or more stabilizer wheels.

In particularly preferred embodiments (all examples) of the invention, the chair is configured to have a folded size and weight suitable to make it portable. In certain particularly preferred embodiments, the total weight of the chair does not exceed about 15 kg, and most preferably does not exceed about 12 kg, thereby making the power chair easily portable. The folded form preferably has a largest dimension no greater than 1 meter, and preferably no greater than about 80 centimeters, and preferably has at least one dimension less than about 50 centimeters.

Turning now to FIGS. 14A-19F , another particularly preferred embodiment of a chair 100 configured and operative in accordance with the teachings of the present invention is shown. In general, chair 100 is similar in structure and function to FIGS. 1A-5 , and like features are similarly numbered. Thus, the chair 100 here also has a seat element 12 with support surfaces 14, 16 for supporting the user sitting in a "seat-facing orientation". A post 18 extends downwardly from the seat element 12 to support the seat element. Seatpost 18 may define a vertical axis 20 . A drive wheel 22 is relatively rotatable about a horizontal axis of rotation to define a direction of forward movement F perpendicular to the axis of rotation, with the seat element 12 lying substantially on the vertical axis 20 . The drive wheel 22 is mechanically connected to the seatpost 18 so that the direction of forward movement F is aligned with the seat-facing direction of the seat element 12 so that rotation of the seat element relative to the vertical axis 20 produces the forward movement Corresponding rotation in direction F.

"Substantially on the axis" in this context means that the position of the wheel is substantially "on the axis" so as to facilitate steering the direction of the wheel by rotating relative to the axis without sufficient frictional resistance to make it difficult for the user to turn the seat chair. This can be achieved using a single center wheel as shown or a pair of wheels close to the axle. When the drive wheels are driven through a differential gear, or by using the phase of rolling resistance when de-energized For the lower two independently driven drive wheels, the distance between the two wheels can be larger. However, these latter options are considered to be unnecessarily bulky and complex for particularly preferred implementations.

The embodiment of Figures 14A-19F also includes a suspension similar to that of Figures 1A-5. As shown in Figures 17A to 17C and 18A, the suspension employs a first spring arrangement (eg, a first helical compression spring 36) to transfer load from the seatpost 18 to the drive wheel 22, and a first A second spring arrangement (eg, second helical compression spring 38 ) is used to transfer the load from the seatpost 18 to the stabilizer assembly 24 . The suspension is not shown in detail here, but will be described above with reference to Figure 1A, and can also be implemented using various other spring-based or hydraulic options as described above.

The stabilizer assembly 24 here also preferably adopts a combination of castor wheels 26 and fixed axle wheels 28 , having a structure and function similar to that of the above-mentioned one unfolded. The fold of the stabilizer assembly 24 is also by providing a central portion 30 mechanically connected to the seatpost 18; a front portion (frame 32) hingedly connected to the central portion 30 at a first articulation axis 58 and supporting two front stabilizer wheels 26; and a rear portion (frame 34) hingedly connected to the central portion 30 at a second articulation axis 60 and supporting two rear stabilizer wheels 28, wherein the first articulation axis 58 and The second hinge axis 60 is preferably an axis parallel to each other so as to facilitate folding the front frame 32 and rear frame 34 into close proximity.

Castors 26 are foldably mounted to front frame 32 by folding wings 62 along a secondary hinge axis 64 which is preferably non-parallel to hinge axis 58 and, in this case, substantially Perpendicular to the hinge axis 58 . Similarly, fixed axle wheels 28 are foldably mounted to rear frame 34 by folding wings 62 along a secondary hinge axis 64, which is preferably non-parallel to hinge axis 60, and in such a case, substantially perpendicular to the hinge axis 60 . In order to simplify the deployment and folding of the wings 62, the stabilizer assembly 24 preferably includes a linkage arranged to hold the front frame 32 and the rear frame 34 when they are rotated relative to their corresponding hinges 58. The folding wings 62 are folded from an unfolded position to a folded position (FIGS. 19B and 19E). In the non-limiting embodiment shown here, the linkage of each wing 62 employs a bar 66 to be hingedly attached to the center section 30 at an offset from the hinge 58 and connected to the front frame along the front frame. 32 side rail slides a slider 68, and a connecting rod 70 is connected to the slider 68 and the wing 62 through a pivotal connection. Thus this configuration, the front frame 32 and rear frame 34 from their fully raised operative position down towards the folded position causes the rod 66 to pull the slider 68 along the side rails of the front frame 32 in the direction of the hinge 58, thereby also pulling the connection. lever 70 to fold the wings 62 inwardly to the folded position of Figure 4B. Conversely, the current frame 32 opens In its deployed state, the movement is reversed and the wings 62 are pushed outward to their deployed state, ready for use. Thus, this mechanism provides an improved lateral wheelbase for the stabilizer assembly 24 while achieving a highly compact folded condition.

This embodiment also features a mechanical linkage that coordinates the folding of the front frame 32 and rear frame 34 . In an implementation, again according to a non-limiting example, partial gear arrangements 72 and 74 are used which are centered on respective axes 58 and 60 and which intermesh to ensure that the two frames are in their Simultaneous and opposite rotations between the unfolded state and its fully collapsed state ( FIGS. 19B and 19E ). The gear arrangement here may also comprise a number of abutment surfaces 76 which define the fully raised deployed position of the frames.

The chair 100 shown here incorporates a number of distinctive features that are believed to provide additional advantages in a number of ways over the chair 10 described above. First, it has been found valuable to provide a height adjustment mechanism that facilitates the installation of chair 100 by the user. In particular, according to a particularly preferred feature of chair 100, a footrest 102 is mechanically connected to a height adjustment mechanism for selectively lowering into contact with an underlying surface (FIGS. 14A and 15B). The contact between the footrest 102 and the underlying surface ensures that the chair is stable when the user places his weight on the footrest when installing the chair. The footrest is then raised from the lower surface by the height adjustment mechanism to provide a required clearance from the floor before the user begins walking (FIG. 15A). Before dismounting, this footboard is lowered to the ground again, thus ensuring stability also when dismounting.

Although the aforementioned footrest adjustment can be provided independently of the other elements of the chair, it is believed that it is preferable that the height difference between the footrest 102 and the seat support surface 14 remain constant to provide a stable and comfortable ride for the user. Sitting configuration. For this reason, it is generally considered preferable that the height adjustment mechanism is integrally formed with the seatpost 18 and arranged to adjust a height of the seat element between a lowered position for mounting and demounting and for driving. between elevated positions. In this case, the footrest 102 is preferably mechanically connected to the height adjustment mechanism so as to move vertically with the seat element 12, while the seat element remains rotatable relative to the vertical axis independently of the footrest. Most preferably, the footrest 102 engages complementary features of the stabilizer assembly when raised to help ensure that the footrest does not rotate relative to the vertical axis. Additionally, according to certain particularly preferred embodiments, the surface of the footrest 102 in the raised position is substantially flush with the upper surface of the front frame 32 of the stabilizer assembly, thereby providing a bonded upper surface, The user's feet may rest against the upper surface when manipulating the chair.

Figures 17A to 17C schematically illustrate a non-limiting exemplary embodiment of a height adjustment mechanism in cross-sectional and cross-sectional views. Specifically, in this embodiment, the core of the seat post 18 is implemented as the shaft of a linear actuator, typically having a drive motor and transmission unit 104 fixed to the seat support surface 14. The interior of a cavity. The linear actuator may be any type of linear actuator suitable for lifting a load of a suitable range over a suitable range of motion, including but not limited to screw actuators and hydraulic actuators. For a wide range of applications, an actuator rated for loads up to about 1500N, with a travel range of 10 cm may be suitable. Such actuators are readily commercially available from a number of sources and therefore will not be described in detail here. The actuator is preferably selected to provide a non-rotatable end link, thereby helping to maintain the angular alignment of the seat and the drive wheel, as described above. The bottom end of the actuator is preferably carried on the suspension means by which the seat load is distributed between the drive wheel and the stabilizer means, as described above.

Incidentally, although the footrests of chair 100 are considered to be particularly advantageous, the chair 10 of the preceding embodiments could optionally be improved by providing a height adjustment mechanism for the seat element 12, even if no adjustable pedals. In the latter case, the lowered position of the seat is used to facilitate installation and removal when the user places their feet on the floor, and the user's feet are then transferred before, during or after the seat is raised to the stabilizer assembly in preparation for driving.

Where a height adjustment mechanism is provided, the chair is preferably operated by an electronic control system comprising logic circuits and/or processing systems configured by appropriate hardware and/or software to ensure proper order of operations. For example, when the seat is in the lowered state, actuating the drive wheels to travel forward or backward is ineffective. Optionally, a user input to steer the chair may automatically translate into a "raise seat" command to prepare for driving. Conversely, when the seat is moving, the lowering of the seat may advantageously be disabled, but before the controller is de-energized, braking of the "off" command may occur automatically to lower the seat. As previously mentioned, the control system may be physically housed within the seat interior volume, in the housing of the central portion of the stabilizer assembly, or anywhere else within the chair assembly, as a single unit or as multiple discrete assemblies.

Inputs to the control system are preferably via a manual lever or rocker switch 122 and/or various other buttons or other inputs, preferably disposed on one or both chair handles 124 . The input is usually connected to the control system via wires passing through the handle, wireless connections are also possible, as are known art low power wireless input devices.

Turning now in more detail to the chair 100 of the particularly preferred but non-limiting exemplary embodiment shown here, the footrest 102 is supported here on a bracket 106 which is hinged to a support arm 108 which The support arm 108 protrudes from an upper column housing 110 . The seat element 12 and the drive motor and transmission unit 104 of the linear actuator are connected to the upper column housing 110 to move vertically as a unit while allowing the seat actuator assembly to rotate relative to the upper column housing 110 .

The bracket 106 is here formed with a notch 112 in which a latch of the stabilizer assembly 24 engages. The latch notch engagement is preferably configured so that in the raised position of the seat and footrest the latch is close enough to the bottom of the notch to prevent the front frame 32 from folding down, thereby preventing The device is folded. As shown in Figure 16B, the latch is located higher in the notch 112 when the seat is lowered. In this position, folding movement of the stabilizer assembly is permitted, and the latch notch engagement further guides pivoting of the bracket 106 relative to its hinges to a more compact inwardly folded position as shown in FIG. 16C.

According to another particularly preferred but non-limiting feature of the footrest 102, the footrest has a foot support surface comprising: a rear portion 112, adjacent to the seat element 14; and a front portion 114, Projecting away from the seat element 14, the front portion 114 and the rear portion 112 are connected in a hinged connection 116 to allow inward folding of the front portion 114 of the foot support surface (see FIG. 19B). This folding motion makes the footrest more compact in the folded state of the chair 100 . In some particularly preferred cases, the folded position can also be used when the seat is raised and used, for example to make it easier to access a table or cupboard.

Turning now to another particularly preferred but non-limiting feature of the chair 100 , the chair as shown here includes a fold assist mechanism 118 for assisting in the folding of the stabilizer assembly 24 . The folding assist mechanism 118, as seen in the expanded view of Figures 18A and 18B, is implemented here as a spring-loaded actuator that is coupled to the height adjustment mechanism and unfolds so that the The seat element is lowered from the raised position (Fig. 18A) to the lowered position (Fig. 18B) so that the actuator comes into contact with a part of the stabilizer assembly (in this case an arm of the rear portion 34) The snap is formed and a load is applied to an inner spring 120 of the actuator which is released during at least part of a folding movement of the stabilizer assembly, thereby facilitating folding of the device. The load on the inner spring 120 is caused by the lowering of the height adjustment mechanism, which ensures that this load occurs selectively when required, avoiding that the spring remains loaded for long periods of time during use of the device. Although shown here as a linearly consistent The actuator is biased by a coil spring, but it will be apparent to those skilled in the art that a wide variety of other actuator configurations and spring types can be used, including but not limited to coil springs, leaf springs, and air compression springs .

The handle 124 of the chair 100 is preferably also embodied as a folding handle. In the embodiment shown here, the handle is pivotally connected to the seat element 12 at the side of the chair and folds away by a rearward pivoting movement. Optionally, the handle is integrally formed by a crossbar 128 passing under the seat in the unfolded state, resting on the central upright of the chair to securely support the handle. The shape of the crossbar and the location of the pivotal connection are selected to allow passage of the bar around the front of the seat so that the handle can be folded back. As shown in Figures 14B, 16C and 19F, the back support surface 16 is preferably provided by a flexible member 126 (a wide band or the like) which flexes around the folding mechanism of the chair when folded.

In all other respects, the chair 100 is similar to the previously described embodiment and is subject to the same range of options and variations, and its structure and function will be fully understood by reference to the above description.

It should be understood that the above description is by way of example only, and that many other embodiments are possible within the scope of the invention, as defined by the appended claims.

12‧‧‧Seat components

14‧‧‧Support Surface

16‧‧‧Support Surface

22‧‧‧Drive wheel

24‧‧‧stabilizer assembly

26‧‧‧Stabilizer wheel

28‧‧‧Stabilizer wheel

32‧‧‧Front frame

34‧‧‧Rear frame

62‧‧‧folding wings

64‧‧‧Auxiliary hinge axis

66‧‧‧Rods

68‧‧‧slide

70‧‧‧connecting rod

100‧‧‧chairs

102‧‧‧Pedals

110‧‧‧Pillar housing

122‧‧‧Rocker switch

124‧‧‧handle

126‧‧‧Flexible components

Claims (19)

A power chair for propelling a user over a lower surface, comprising: (a) a seat element having support surfaces for supporting the user seated in a seat-facing orientation; ( b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel rotatable relative to a horizontal axis of rotation to define a a forward direction of movement of the axis of rotation, the drive wheel being located below the seat element and substantially on the vertical axis, the drive wheel being mechanically connected to the seatpost to maintain the forward direction of movement aligned with the seat-facing direction, such that rotation of the seat element relative to the vertical axis causes a corresponding rotation in the forward direction of motion; (d) a motor, in driving connection with the drive wheel, to drive the drive wheel in rotation relative to the horizontal axis of rotation, thereby propelling the electric chair in the seat-facing direction; (e) a stabilizer assembly, mechanically coupled to the seatpost, comprising a set of stabilizer wheels mounted on a support structure for supporting the seat post in a vertical direction, the stabilizer assembly allows the seat post to rotate about the vertical axis relative to the support structure; and (f) a suspension, associated with the seat post, the drive wheel, and the stabilizer assembly connected, wherein the suspension device includes a first suspension spring and a second suspension spring, the first suspension spring is arranged for transmitting a load between the seatpost and the drive wheel; and the second Suspension springs are deployed for transferring a load between the seatpost and the support structure, the suspension arrangement being configured to spread a load of the user seated stably on the seat element so as to remain at A predefined proportional range between a load supported by the drive wheel and a load supported by the stabilizer wheels. The electric chair as claimed in claim 1, wherein the suspension device is configured to distribute the load of the user sitting stably on the seat element so that a substantially constant proportion of the user's body weight passes through the The drive wheels support, and the user's weight is supported by the stabilizer wheels within a remaining proportion of the user's weight in any range between 50 kg and 100 kg, the substantially constant proportion being the use Between 30% and 90% of the patient's body weight. The electric chair as described in claim 1, wherein the suspension device includes a first hydraulic device and a second hydraulic device, the first hydraulic device includes at least one piston, and the first hydraulic device is deployed for transmitting a load between the seat post and the drive wheel, and the second hydraulic device comprising at least one piston, the second hydraulic device being arranged to transmit a load between the seat post and the support structure, wherein the The first hydraulic device and the second hydraulic device are connected to each other through a pressure balance pipeline. The electric chair according to claim 1, wherein the set of stabilizer wheels includes at least one fixed-axis driven wheel and at least one caster wheel mounted so as to rotate to adjust the steering of the electric chair. The electric chair as described in claim 4, wherein the set of stabilizer wheels includes at least two fixed-axis driven wheels and at least two caster wheels mounted so as to rotate to adjust the steering of the electric chair. The electric chair of claim 1, wherein the support structure comprises: a central portion mechanically connected to the seat post; a front portion hingedly connected to the central portion at a first hinge axis and supporting the set two front wheels in the stabilizer wheels; and a rear portion hingedly connected to the central portion at a second articulation axis and supporting the two rear wheels in the set of stabilizer wheels, wherein the first and second articulation axes are axes parallel to each other. The electric chair as described in claim 6, wherein the two front wheels are two casters, which are foldably mounted to the front part along an auxiliary hinge axis through several folding wings, and the auxiliary hinge axis is not parallel to the The first hinge axis, the support structure also includes a link arranged to fold the folded wings from an unfolded position to a folded position when the front portion is rotated relative to the first hinge axis. The electric chair as described in any one of the preceding patent claims, wherein the electric chair further comprises: a height adjustment mechanism integrally formed with the seatpost, arranged to adjust a height of the seat element above the lower surface height between a lowered position for installation and removal and a raised position for driving. The electric chair as claimed in claim 8, wherein the electric chair further comprises: a foot pedal, mechanically connected to the height adjustment mechanism, to move vertically with the seat element, so that when the seat element is lowered When brought into contact with the lower surface when in position and lifted away from the lower surface in the raised position of the seat element, the seat element is rotatable relative to the vertical axis independently of the footrest. The electric chair of claim 9, wherein the stabilizer assembly is a foldable stabilizer assembly that can be folded from an unfolded state for supporting the electric chair to a folded state for compact storage and transportation, and wherein The footrest is mechanically connected to the stabilizer assembly to block the stabilizer assembly from collapsing from the deployed state to the folded state when the footrest is in the raised position. The electric chair as claimed in claim 9, wherein the footrest has a foot support surface, and the foot support surface includes: a rear portion, close to the seat element; and a front portion, protruding away from the seat element, the front portion The front portion and the rear portion are connected in a hinged manner to allow the front portion of the foot support surface to be folded inwardly. The electric chair of claim 8, wherein the stabilizer assembly is a foldable stabilizer assembly that can be folded from an unfolded state for supporting the electric chair to a folded state for compact storage and transportation; the The power chair also includes a folding assist mechanism for assisting in folding of the stabilizer assembly, the folding assist mechanism comprising a spring loaded actuator coupled to the height adjustment mechanism and unfolding such that the seat The chair element is lowered from the raised position to the lowered position, causing the actuator to come into engagement with a portion of the stabilizer assembly, and to apply a load to an internal spring of the actuator that is tied to the stabilizer The assembly is released during at least part of a folding movement. An electric chair for propelling a user over a lower surface, comprising: (a) a seat element having support surfaces for supporting the user seated in a facing direction of the seat; (b ) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel rotatable relative to a horizontal axis of rotation to define a A direction of forward movement of the axis, the drive wheel is located below the seat element and substantially on the vertical axis, the drive wheel is mechanically connected to the seatpost to keep the forward direction of movement aligned with the seat-facing direction so that Rotation of the seat element relative to the vertical axis causes a corresponding rotation in the forward direction of motion; (d) a motor, in driving connection with the drive wheel, to drive the drive wheel in rotation relative to the horizontal axis of rotation, thereby propelling the power chair in the seat-facing direction; and (e) a stabilizer assembly mechanically coupled to the seatpost, the stabilizer assembly comprising a set of stabilizer wheels mounted on a support structure for supporting the seat post in a vertical direction, the stabilizer assembly allows the seat post to rotate about the vertical axis relative to the support structure; wherein the set of stabilizer wheels includes at least two fixed axle driven wheels and at least two caster wheels load in order to turn to adjust the steering of the power chair. A power chair for propelling a user over a lower surface, comprising: (a) a seat element having support surfaces for supporting the user seated in a seat-facing orientation; ( b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel rotatable relative to a horizontal axis of rotation to define a direction of forward movement perpendicular to the axis of rotation, the drive wheel being located below the seat element and substantially on the vertical axis, the drive wheel mechanically connected to the seatpost to keep the forward direction of motion aligned with the seat-facing direction so that rotation of the seat element relative to the vertical axis causes a corresponding rotation of the forward direction of motion; (d) a motor , forming a driving connection with the drive wheel to drive the drive wheel to rotate relative to the horizontal axis of rotation, thereby propelling the electric chair along the seat-facing direction; and (e) a stabilizer assembly mechanically connected to the seat post, The stabilizer assembly includes a set of stabilizer wheels mounted on a support structure for supporting the seatpost in a vertical direction, the stabilizer assembly allowing the seatpost to move about the vertical axis relative to the support structure swivel; wherein the support structure comprises: a central portion mechanically connected to the seat post; a front portion hingedly connected to the central portion at a first articulation axis and supporting two front wheels in the set of stabilizer wheels and a rear portion hingedly connected to the central portion at a second articulation axis and supporting two rear wheels in the set of stabilizer wheels, wherein the first and second articulation axes are axes parallel to each other. The electric chair as claimed in claim 14, wherein the two front wheels are two castor wheels, which are foldably mounted to the front part along an auxiliary hinge axis by a plurality of folding wings, and the auxiliary hinge axis is not parallel to the first hinge axis, the support structure further comprising a link arranged to fold the folded wings from an unfolded position to a folded position when the front portion is rotated relative to the first hinge axis . An electric chair for propelling a user over a lower surface, comprising: (a) a seat element having support surfaces for supporting the user seated in a seat-facing orientation; (b) a post extending downwardly from the seat element to support the seat element, the seat post defining a vertical axis; (c) a drive wheel rotatable about a horizontal axis of rotation to define a vertical axis A forward direction of movement of the axis of rotation, the drive wheel located below the seat element and substantially on the vertical axis, the drive wheel being mechanically connected to the seatpost to maintain the forward direction of movement aligned with the seat-facing direction , such that rotation of the seat element relative to the vertical axis causes a corresponding rotation in the forward direction of motion; (d) a motor, in driving connection with the drive wheel, to drive the drive wheel to rotate relative to the horizontal axis of rotation , so that the power chair is propelled in the seat-facing direction; (e) a stabilizer assembly, mechanically connected to the seat post, the stabilizer assembly comprising a set of stabilizer wheels mounted on a support structure for supporting the seatpost in a vertical orientation, the stabilizer assembly allows the seatpost to rotate about the vertical axis relative to the support structure; (f) a height adjustment mechanism, integrally formed with the seatpost, deployed for adjusting a height of the seat element above the lower surface between a lowered position for installation and removal and a raised position for driving; and (g) a footrest, mechanically Connected to the height adjustment mechanism to move perpendicular to the seat element so as to be brought into contact with the underlying surface in the lowered position of the seat element and to be brought into contact with the underlying surface in the raised position of the seat element Lifted off the lower surface, the seat element is rotatable relative to the vertical axis independently of the footrest. The power chair of claim 16, wherein the stabilizer assembly is a foldable stabilizer assembly that is foldable from an unfolded state for supporting the power chair to a folded state for compact storage and transport, and Wherein the footrest is mechanically connected to the stabilizer assembly so as to block the stabilizer assembly from collapsing from the unfolded state to the folded state when the footrest is in the raised position. The electric chair as claimed in claim 16, wherein the footrest has a foot support surface comprising: a rear portion adjacent to the seat element; and a front portion protruding away from the seat element, the front portion The front portion and the rear portion are connected in a hinged manner to allow the front portion of the foot support surface to be folded inwardly. The electric chair of claim 16, wherein the stabilizer assembly is a foldable stabilizer assembly that can be folded from an unfolded state for supporting the electric chair to a folded state for compact storage and transport; the The power chair also includes a fold assist mechanism for assisting in folding of the stabilizer assembly, the fold assist mechanism comprising a spring loaded actuator coupled to the height adjustment mechanism and unfolding such that the The seat element is lowered from the raised position to the lowered position, causing the actuator to come into engagement with a portion of the stabilizer assembly, and to apply a load to an internal spring of the actuator, the load being tied to the stabilizer assembly. is released during at least part of a folding movement of the implement assembly.

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