TECHNICAL FIELD

The present disclosure, in general, relates a medical and support device. Particularly, but not exclusively, the present disclosure relates to a wheelchair. Further, embodiments of the present disclosure relate to a mechanism for maneuvering the wheelchair.

BACKGROUND OF THE DISCLOSURE

Subjects such as human beings suffering from ailments including, but not limited to, illness, injury, old age, and disability partial or complete at a lower portion of torso may generally require assistance for gait operations such as, walking, climbing and the like. Such assistance is provided to the subject in the form of a handheld walker or a wheelchair.

Generally, wheelchairs are used for movement of the subjects, where such wheelchairs includes with a seat, a back-support, and at least two large wheels positioned on either side of the seat. With such configuration of the wheelchair, the subject may be capable of manually operating the wheelchair for maneuvering. Axes of the large wheels may typically deviated from center of gravity of the wheelchair and in-turn that of the subject in the wheelchair due to which the wheelchair may be incapable of maneuvering on uneven terrain. Further, two relatively small caster wheels may also be provided at front portions of the seat, to support and balance the wheelchair. A handle may be provided adjacent the back-support such that an assistant may push or pull the wheelchair and transport the subject. However, the conventional wheelchair requires continuous activity of the subjects arms and hands, which cannot be rested during travel. The physical effort involved is considerable and significantly limits feasible travel distances, even with th e aid of the assistant.

With advancements in technology, motorized wheelchairs have been developed that employ electric motors coupled to the wheels of the wheelchair to drive and maneuver. The electric motors drive the wheelchair and minimizes human effort required by the subject or an assistant for guiding the wheelchair. However, the subject may encounter problems while reaching various premises, including clinics, hospitals, public institutions, schools, and everyday obstacles that restrict freedom of movement as the wheelchair path may consist of stairs and uneven surfaces. Also, conventional wheelchair may not be suitable for uneven terrain, as coupling of the electric motors to the wheels may be affected when travelling through obstacles on such uneven terrain. Further, the motorized wheelchairs may be adapted with cluster wheels at each corner of the wheelchair to maneuver over uneven terrain. The wheelchairs with cluster wheels are adapted with a plurality of stabilizing mechanism at each wheel cluster to stabilize the wheelchair when maneuvering over the uneven terrain. The incorporation of wheel clusters and the plurality of stabilizing mechanisms for each wheel cluster increases the complexity of the wheelchair and increases manufacturing cost, effort, and time. Further, the wheelchairs adapted with the cluster wheels are not capable of freewheeling which is an important feature when the wheelchair has to be pushed by an assistant.

The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the conventional mechanisms.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of the prior art are overcome by a mechanism and a system as claimed and additional advantages are provided through the mechanism and the system as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure a mechanism for maneuvering a wheelchair is disclosed. The mechanism includes a first link pivotally connectable to a frame of the wheelchair at one end. A second link is pivotally connected to an other end opposite to the one end of the first link. An actuator is coupled between the first link and the second link, where the actuator is configured to displace the second link relative to the first link. Displacement of the first link and the second link stabilizes position of the frame relative to a horizontal plane of the wheelchair. Further, the mechanism includes a wheel mounting assembly consisting of a wheel receiving portion and a shaft extending from the wheel receiving portion, where the shaft is pivotally connected to a free end of the second link. Furthermore, a pair of wheel assemblies are coupled to the wheel receiving portion, where the pair of wheel assemblies are operable to maneuver the wheelchair. A stopper is positioned between a free end of the second link and the shaft to limit movement of the wheel mounting assembly relative to the second link within predetermined limit.

In an embodiment, the stopper is defined with a cutout to receive the shaft.

In an embodiment, the stopper comprises protrusions extending in the cutout, where the shaft abuts the protrusions after a predetermined degree of rotation.

In an embodiment, each of the pair of wheel assemblies include a wheel coupler that is connectable to the wheel receiving portion of the wheel mounting assembly. Further, a wheel is disposed m the wheel coupler, where the wheel rotates relative to the wheel coupler.

In an embodiment, the wheel mounting assembly is adapted to receive the wheel coupler at opposite sides of the wheel receiving portion.

In an embodiment, the wheel includes a rotaiy actuator to selectively displace the wheel.

In an embodiment, the wheel comprises a one way bearing which is coupled to the rotary actuator, where the one way bearing is configured to enable operation of the rotaiy? actuator when wheel speed is equal to zero.

In an embodiment, the wheel includes a wheel mat configured to impart predetermined friction between the wired and a maneuvering surface.

In another non-limiting embodiment of the present disclosure, a wheelchair is disclosed. The wheelchair includes a frame and a seating portion defined on the frame. Further, a plurality of mechanisms are provided in at least one corner of the frame for maneuvering the wheelchair. Each of the plurality of the mechanisms include a first link pivotally connectable to the frame of the wheelchair at one end and a second link is pivotally connected to an other end opposite to the one end of the first link. An actuator is coupled between the first link and the second link, where the actuator is configured to displace the second link relative to the first link. Displacement of the first link and the second link stabilizes position of the frame relative to a horizontal plane of the wheelchair. Further, the mechanism includes a wheel mounting assembly consisting of a wheel receiving portion and a shaft extending from the wheel receiving portion, where the shaft is pivotally connected to a free end of the second link. Furthermore, a pair of wheel assemblies are coupled to the wheel receiving portion, where the pair of wheel assemblies are operable to maneuver the wheelchair. A stopper is positioned between a free end of the second link and the shaft to limit movement of the wheel mounting assembly relative to the second link within predetermined limit.

In an embodiment, the wheelchair consists of an adjustable footrest connectable to the frame, where the adjustable footrest include plurality of mounting points to connect the footrest to the frame.

In an embodiment, the wheelchair consists of a controller associated with the wheelchair, where the controller is configured to receive inputs and drive the wheelchair.

In an embodiment, the wheelchair includes a housing provisioned below the seating portion, where the housing is adapted to accommodate electrical components of the wheelchair.

In an embodiment, the wheelchair includes a sensor module that is connectable to the frame and is configured to determine the angle of inclination of the frame.

In an embodiment, the wheelchair consists of a control unit which is configured to control the actuator coupled between the first link and the second link and a rotary actuator accommodated in the wheel.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description,

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in winch:

Fig. 1 illustrates a schematic view of a wheelchair including a mechanism for maneuvering a wheelchair, in accordance with an embodiment of the present disclosure.

Fig. 2 illustrates a schematic view' of a frame of the wheelchair of Fig. 1.

Figs. 3a and 3b illustrate a perspective and a front views of a first link and a second link of the mechanism of Fig 1.

Fig. 4 illustrates a perspective view of a wheel mounting assembly of the mechanism, in accordance with an embodiment of the present disclosure.

Fig. 5 illustrates a perspective view of a stopper of the mechanism, in accordance with an embodiment of the present disclosure.

Fig. 6 illustrates a perspective view of a wheel coupler, in accordance with an embodiment of the present disclosure.

Figs. 7a, 7b, 7c and 7d illustrate schematic views of a wheel, in accordance with an embodiment of the present disclosure.

Fig. 8 is a flow chart illustrating working of the mechanism, in accordance with an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the system and method illustrated herein may he employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that, the conception and specific embodiments disclosed may be readily utilized as a basis for modifying other mechanisms, methods, processes, systems, devices, and assemblies for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that, such equivalent constructions do not depart from the scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristics of the disclosure, to its system, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a nonexclusive inclusions, such that a mechanism, an assembly, or a device that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus proceeded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

A wheelchair is a device consisting of a chair coupled with wheels that is employed as a means of transport for a subject who is unable to walk as a result including, but not limited to, illness, injury, disability, and the like. The wheelchair may have fixed wheels which are manually operated by the limbs of the subject or an assistant of the subject and may be powered by electric actuators to reduce manual effort by the subject or the assistant. Further, as the wheelchair is fixed to wheels for driving, the wheelchair is restricted to flat surfaces and cannot be driven over uneven terrain, for example, stairs. Furthermore, the wheelchair when driven over uneven terrain, the wheelchair may tilt and create dangerous situations for the subject. Accordingly, the present disclosure disclose a wheelchair which overcomes one or more limitations of the conventional wheel chairs.

In accordance with various embodiments of the present disclosure, a wheelchair is disclosed. The wheelchair includes a frame and a seating portion defined on the frame. Further, a plurality of mechanisms are provided in at least one corner of the frame for maneuvering the wheelchair. Each of the plurality of the mechanisms include a first link pivotally connectable to the frame of the wheelchair at one end and a second link is pivotally connected to an other end opposite to the one end of the first link. An actuator is coupled between the first link and the second link, where the actuator is configured to displace the second link relative to the first link. Displacement of the first link and the second link stabilizes position of the frame relative to a horizontal plane of the wheelchair. Further, the mechanism includes a wheel mounting assembly consisting of a wheel receiving portion and a shaft extending from the wheel receiving portion, where the shaft is pivotally connected to a free end of the second link. Furthermore, a pair of wheel assemblies are coupled to the wheel receiving portion, where the pair of wheel assemblies are operable to maneuver the wheelchair. A stopper is positioned between a free end of the second link and the shaft to limit movement of the wheel mounting assembly relative to the second link within predetermined limit. The mechanism enables the wheelchair to maintain stability and maneuver over uneven terrain.

Reference wall now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Wherever possible, same numerals will be used to refer to the same or like parts. The following paragraphs describe the present disclosure with reference to Figs. 1-8.

Fig. 1 illustrates a wheelchair (100) according to an illustrative embodiment of the disclosure. The wheelchair (100) includes a frame (200) and a seating portion (201, 204) defined on the frame (200). The frame (200) may be made of rigid materials including but not limited to metal, metal alloy, polymer, wood, carbon fiber and any other material capable of withstanding loads exerted by the subject. Further, the wheelchair (100) is provided with a plurality of mechanisms (10) [explained in detail below in figs. 3-8] for maneuvering and stabilizing. Each of the plurality of mechanisms (10) is provided in at least one corner of the frame (200) for maneuvering the wheelchair (100), however, such mechanisms may also be incorporated about any side of the frame (200) to aid in maneuvering such wheelchair (100).

Referring now to figure 2, which illustrates the frame (200) and the seating portion (201 , 204). The frame (200) includes a frame base (209) coupled to the frame (200), where the frame base (209) may be structured to accommodate a housing (208), In the illustrative embodiment, the housing (208) may be provisioned at a bottom portion of the frame (200) and be located below the seating portion (201 , 204), however, such construction may not be considered as a limitation as the housing may also be positioned relative to other sections of the frame (200) including but not limited to, front portion, rear portion, and side portion, based on structural requirement. The housing (208) is adapted to accommodate the electrical components of the wheelchair (100), which include but not limited to batteries (807), wires, wiring harnesses, control unit (801), electrical drivers (804), sensor module (806), memory units and any other component employed to control the wheelchair (100). The housing (208) may be configured to support a seat base (204) of the seating portion (201, 204) and may include a backrest (201) connected to the seat base (204) at a predetermined angle based on seating requirements of the subject. The seat base (204) and the backrest (201) may be relatively adjustable, based on requirements of the subject. Further, a left armrest (202) and a right armrest (203) are fixed at one end to the seat base (204) and another end to the backrest (201) and may be configured to provide support to arms of the subject. At least one of the left armrest (202) and the right armrest (203) may be adapted to accommodate a controller (802). The controller (802) may include a user interface [not shown] to receive inputs from the subject or the assistant of the subject to control the mechanism (10) and drive the wheelchair (100). Furthermore, the left armrest (202) and the right armrest (203) may be hollow' to enable routing of wires and waring harnesses from the housing (208) to the controller (802). In an embodiment, the inputs from the subject or the assistant of the subject to the controller (802) may be including, but no limited to, a tactile input, a voice command, a press button, a joystick interface and any other form of input that may allow controlling and maneuvering of the wheelchair (100).

Further, the wheelchair (100) consists of an adjustable footrest (207), which may be adapted to support each lower limbs of the subject. The adjustable footrest (207) may be connectable to the frame (200) of the wheelchair (100), and the adjustable footrest (207) may include a plurality of mounting points to connect such footrest to the frame (200). In an exemplary embodiment, the adjustable footrest (207) may be connected to the seat base (204) through a leg length adjustment link (205) consisting of multiple mounting points to fix the adjustable footrest (207) capable of adjusting the distance of the adjustable footrest (207) from the seat base (204). Furthermore, a leg angle adjustment link (206) may be connectable to the seat base (204) at one end and another end to the leg length adjustment link (205) for adjusting the angle of the lower limbs of the subject. In an embodiment, the leg angle adjustment link (206) and the seat base (204) may also have multiple mounting points to enable the subject to modify the position of the footrest. The wheelchair (100) may be provided with a pair of adjustable footrest (207), a pair of leg length adjustment links (205) and a pair of leg angle adjustment links (206) each provisioned on the sides of the frame (200) or the seat base (204). The adjustable footrest (207), the leg length adjustment links (205) and the leg angle adjustment links (206) may be fixed by fasteners, in an embodiment, controlling operations of the adjustable footrest (207) may be performed based on inputs from the subject or the assistant of the subject to the controller (802).

In an embodiment, the leg length adjustment link (205) and the leg angle adjustment link (206) may be adapted to slide along the frame (200) of the wheelchair (100) through sliding mechanism. Further, the leg length adjustment link (205) and the leg angle adjustment link (206) may be formed telescopically to adjust the length and the angle of the adjustable footrest (207). Further, the adjustable footrest (207) may be slidably connected to the leg length adjustment link (205).

The mechanism (10) for maneuvering and stabilizing the wheelchair (100) may include [as illustrated in Fig. 3a and 3b] a first link (301), which may be pivotally connectable to the frame (200) of the wheelchair (100) at one end by a first support shaft (302). The first support shaft (302) may be accommodated through a first bearing (317). The first bearing (317) may be supported within a first bearing holder (303). The first bearing holder (303) may consist of a bearing step (402) within which the first bearing (317) may be accommodated which prevents displacement of the first bearing (317). A second link (312) may be pivotally connected to an other end opposite to the one end of the first link (301) through a second support shaft (310). A second bearing (311) may be attached on both sides of the second support shaft (310). Further, an actuator (307) is coupled between the first link (301) and the second link (312). In an embodiment, the actuator (307) may be a linear actuator [hereafter referred to as linear actuator (307)]. The linear actuator (307) is configured to displace the second link (312) relative to the first link (301), where displacement of the first link (301) and the second link (312) stabilizes position of the frame (200) relative to a horizontal plane of the wheelchair (100). In an embodiment, the linear actuator (307) may displace the first link (301 ) relative to the second link (312). That is, relative displacement of the first like (301) and the second link (312) may maintain the seating portion (201, 204) on the horizontal plane of the wheelchair (100), thereby stabilizing orientation of the subject during maneuvering on uneven terrain. In an exemplary embodiment, a slider coupler (306) may be attached to the linear actuator (307). The slider coupler (306) may be connected to at least one slider block (305), which are configured to displace on a corresponding slider rail (308). The slider coupler (306), the slider block (305) and the slider rail (308) may be provisioned on the first link (301) or the second link (312). Further, a first slider stopper (304) and a second slider stopper (309) may be provisioned on the top and bottom of the slider rail (308) to limit the motion of the linear actuator (307).

In an embodiment, the actuator (307) may be a rotary actuator.

In an exemplary embodiment, an outer covering (314) may provisioned on the second link (312) to connect and cover the linear actuator (307). The outer covering (314) may protect the linear actuator (307) from foreign particles during maneuvering of the wheelchair (100) and may also provide reinforcement during maneuvering. Further, the outer covering (314) may be provisioned in the first link (301) to connect the linear actuator (307). In an embodiment, the linear actuator (307) may be at least one of but not limited to electric linear actuator, pneumatic linear actuator, hydraulic linear actuator, and any other actuator capable of actuating linearly.

In an embodiment, a rotary' ^· actuator may be coupled between the first link (301) and the second link (312) that may be configured to displace the second link (312) relative to the first link (301) or displace the first link (301) relative to the second link (312).

Further, the mechanism (10) includes a wheel mounting assembly (400) [as seen in fig. 4], The wheel mounting assembly (400) may include a wheel receiving portion (403) in the form of a rectangular tube, and a shaft (401) extending from the wheel receiving portion (403). The shaft (401 ) may be pivotally connected to a free end of the second link (312). The free end of the second link (312) may be provisioned with a second bearing holder (313) for accommodating a third bearing (315) on either side of the second link (312), to receive the shaft (401) of the wheel receiving portion (403), In an embodiment, the second bearing holder (313) may consist of the bearing step (402) within which the third bearing (315) may be accommodated to prevents displacement of the third bearing (315). Additionally, the shaft (401 ) may be defined with a bearing step (402) extending from a portion of the shaft (401) to restrict movement of the shaft (401) and the tlnrd bearing (315) when the shaft (401) is received in the third bearing (315). In an embodiment, a restrictor (316) may be connected adjacent to the second bearing holder (313) which is configured to selectively restrict movement of the wheel mounting assembly (400) by locking the shaft (401).

Fig. 5 illustrates a stopper (500) connected to the free end of the second link (312) and positioned between the free end of the second link (312) and the shaft (401 ) m order to limit movement of the wheel mounting assembly (400) relative to the second link (312) wathin predetermined limit. The stopper (500) may be defined with a cutout provisioned with a stopper bearing (502) to receive the shaft (401). Further, the stopper (500) includes protrusions (503) extending into the cutout at predefined locations, adapted to abut with the stopper bearing (502) to limit movement of the stopper bearing (502) within the predetermined limit after a predetermined degree of rotation of the shaft (401). The protrusion (503) limits rotation of the wheel mounting assembly (400) within the predetermined limit. In an embodiment, the predetermined limit may be in the range of 60 degrees to 90 degrees.

In an embodiment, the protrusions (503) may have a rectangular profile, a cylindrical profile, V- shaped profile, U-shaped profile, and any other profile capable of restricting rotation of the stopper bearing (502). Further, the protrusions (503) may be positioned at diametrically opposite locations within the cutout.

Furthermore, the mechanism (10) may include a pair of wheel assemblies coupled to the wheel receiving portion (403), where the pair of wheel assemblies may be operable to maneuver the wheelchair (100). Each of the pair of wheel assemblies include a wheel coupler (600) connectable at opposite sides of the wheel receiving portion (403) of the wheel mounting assembly (400) and a wheel (700) which may be disposed in the wheel coupler (600).

Referring now to Fig. 6, the wheel coupler (600) is defined with a wheel connector (601) adapted to house the wheel (700) configured to rotate relative to the wheel coupler (600). The wheel (700) may be rigidly housed in the wheel connector (601) by fixing the wheel (700) with a plurality of coupler extrusions (602) extending from the wheel connector (601). The plurality of coupler extrusions (602) may be defined with a hole to receive a fastener to fix the wheel (700). Further, the wheel coupler (600) may be defined with a wheel mounting assembly connector (603) extending from the wheel connector (601). The wheel mounting assembly connector (601) is defined with a plurality of holes to receive a fastener and fix the wheel coupler (600) with the wheel mounting assembly (400).

In an embodiment, the wheel mounting assembly (400) may be provisioned with plurality of holes at opposite sides of the wheel receiving portion (403) which may be adapted to receive the wheel coupler (600) and fasteners.

Figs. 7a, 7b, 7c and 7d illustrate the wheel (700) of the wheel assembly. The wheel (700) may include a rotary actuator configured to selectively displace the wheel (700). The rotary actuator (702) may be connected to a rotary actuator shaft (706) extending from the rotary actuator (702). Further, the rotary actuator (702) may be housed within a rotary? actuator casing (709). The rotary ^? actuator casing (709) may be housed within and coupled to a one way bearing (708). The one way bearing (708) may be configured to enable operation of the rotary actuator (702) when the wheel speed is equal to zero. Further, an inner rim support (707) is provisioned over the one way bearing (708). The inner rim support (707) is adapted to rigidly connect to an inner rim (703) and restrict displacement of the inner rim (703).

Further, the wheel (700) may include an outer nm (704) defined with plurality of spokes and may consi st of a rim extension (705) extending from the center of the outer rim (704). The rim extension (705) of the outer rim (704) may be configured to receive the rotary actuator shaft (706) to rotate with the rotary actuator (702). Further, the outer rim (704) may be defined with holes to receive fasteners connecting the inner rim (703) with the outer rim (704). In an embodiment, the rotary ^? actuator shaft (706) may be defined with a key configured to be received rim extension (705) of the outer run (704) to enable positive locking.

In an exemplary embodiment, the wheel (700) may include a wheel mat (701) covering the periphery of the wheel (700). The wheel mat (701) may be made of material having high friction to impart predetermined friction between the wheel (700) and a maneuvering surface to provide the required traction. The predetermined friction may correspond to the friction required to provide traction to the wheel (700) during maneuvering over the uneven surface. In an embodiment, the wheel mat (701) may be made of materials including but not limited to foam, rubber, plastic and any other polymeric material suitable for imparting predetermined friction between the wheel (700) and a maneuvering surface to provide the required traction.

In an embodiment, the one way bearing (708) may separate the rotary actuator casing (709) of the rotary actuator (702) from the inner nm (703) support such that the rotary actuator (702) and the rotary^ actuator casing (709) may be selectively independent from the rotary actuator shaft (706). Further, the one way bearing (708) may' enable freewheeling operation, allowing the wheelchair (100) to be manually pushed by the assistant.

Fig. 8 is a flow _' chart showing w'orkmg of the mechanism (10). The subject upon providing inputs to the controller (802) provisioned on the armrest (202, 203), operational signals indicative of velocity' and braking information are transmitted to the control unit, which is provisioned, along with other electronic components, inside the housing (208). The control unit (801) upon receiving the operational signals from the controller (802) is configured to activate the first microcontroller (803) to actuate the rotary actuator (702) in the wheels (700) through electrical drivers (804). In an embodiment, the subject upon operating the controller (802) to adjust the height of the wheelchair (100), the operational signals are transmited to the control unit (801) and the control unit (801) is configured to activate the second microcontroller (805) to operate the linear actuators (307) disposed between the first link (301) and the second link (312).

Further, the subject upon maneuvering the wheelchair (100) over the uneven terrain, a continuous feedback loop is established using the sensor module (806) that is connectable to the frame (200) and may be configured to determine the angle of inclination of the frame (200). The inclination information is transmitted to the second microcontroller (805), which adjusts the length of the individual linear actuators (307) either in the front or rear of the wheelchair (100) to maintain horizontal position.

In an embodiment, rechargeable batteries (807) may used to power the wheelchair (100). The batery (807) may be accessed through a charging port defined on the housing (208). In an embodiment, the control unit (801) may include specialized processing units such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc.

In an embodiment, the wheelchair (100) may displace forward by the rotary motion of all wheels (700) of the mechanism (10) provisioned at each corner of the frame (200).

In an embodiment, the wheels (700) on coming in contact with the uneven surface, for example, stair, the force on the wheel (700) in contact with the stair enables the wheel mounting assembly (400) to rotate. The rotation of the wheel mounting assembly (400) combined with the torque provided by the remaining wheels (700) of the plurality of mechanisms (10) enable the wheel (700) m contact with the stair to rise up onto the stair. Further, as the wheelchair (100) displaces forward, the wheel mounting assembly (400) engages with the edge of the stair. The impact of the wheel mounting assembly (400) engaging with the edge of the stair, along with the torque provided by the rotary^ actuator (702), propel the next set of wheels (700) onto the stair. The sensor module (806) may determine the angle of inclination of the frame (200) and transmit signals to the second microcontroller (805) for adjusting the length of the linear actuators (307) individually to maintain horizontal position of the wheelchair (100) that ensures stability'.

In an embodiment, when the wheelchair (100) climbs down the uneven surface for example, stair, the wheel mounting assembly (400) rotates based on the influence of gravity'. When, the wheels (700) are displacing off the stair, the gravitational force may cause the wheelchair (100) to tilt forward and the wheel mounting assembly (400) tilts down to ensure the wheels (700) come in contact with the stair. Further, the sensor module (806) may determine the angle of inclination of the frame (200) and transmit signals to the second microcontroller (805) for adjust the length of the linear actuators (307) individually to maintain horizontal position of the wheelchair (100).

In an embodiment, the controller (802) may be employed to restrict displacement of the wheelchair (100) by de-actuatmg the rotaiy actuators (702) and eliminates the need for a mechanical braking system. In an embodiment, the control unit (801) may be configured to control velocities of the wheels (700) at each comer of the frame (200) to turn towards the direction of the slower wheels. The mechanism (10) enables the wheelchair (100) to have a small turning radius. The velocities of the wheels (700) may be varied to achieve different turning radius.

In an embodiment, the shaft (401) of the wheel mounting assembly (400) extends from a location on the wheel receiving portion (403) proximal to the front side of the wheel receiving portion (403). It should not be construed that the shaft (401) extends proximal to the front side of the wheel receiving portion (403) as the shaft (401) may extend from any location on the wheel receiving portion (403).

In an embodiment, the mechanism (10) may be employed in rovers and other all-terrain vehicles.

In an embodiment, the rotary actuator (702) may be an electric motor and any other actuator capable of rotary actuation.

In an embodiment, the sensor module (806) may be an array of sensors including but not limited to accelerometer, gyroscope and any other sensor capable of determining the dynamics of an object

In an embodiment, the sensor module (806) may include a gyroscopic sensor, angle sensor, slope sensor and any other sensor capable of determining the angle of inclination.

In an embodiment, the housing (208) may be manufactured to be waterproof and prevent any water or moisture from entering the housing (208).

In an embodiment, an angle of reclination of the backrest (201) may be adjusted as per requirement.

In an embodiment, dampeners may be attached to the mounting points or fastening points of the wheelchair (100) to reduce vibrations. In an embodiment, rotary encoders may be connected to each wheel (700), for precise speed control. Further, linear encoders may be connected to the linear actuators, for precise differential slope control.

In an embodiment, the mechanism (10) ensures that least four points of contact between the wheelchair (100) and the ground are maintained.

In an embodiment, the mechanism (10) enables the wheelchair (100) to travel over uneven terrain.

In an embodiment, the mechanism (10) enables the subject to adjust the height of the seating portion (201, 204) as per requirement.

In an embodiment, the mechanism (10) enables adjustment of the height of the front and back portions of the frame (200) separately, maintains the subject from tilting forwards and backwards during movement.

In an embodiment, the mechanism (10) ensures even weight distribution between the front and rear portion of the wheelchair (100).

In an embodiment, the one way bearing (708) in the wheels (700) enables freewheeling by disengaging the wheels (700) from the rotary? actuator shaft (706) m situations where the wheelchair (100) has to be pushed manually.

In an embodiment, the wheelchair (100) is compact with small wheels (700) so as to be driven in small spaces. Further, the wheelchair (100) consists of adjustable footrest (207) to suit different body sizes of the subject

Equivalents:

Embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within scope of the embodiments as described herein.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers, or steps, but not the exclusion of any other element, integer or step, or group of elements, integers, or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more el ements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary'. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

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