# US 2023/0056464 A1 · Advanced wheelchair > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2023/0056464 A1 - Document ID: US20230056464A1 - Status: Published application - Kind: A1 - Application number: 17/796,851 - Filed: 2021-02-01 - Published: 2023-02-23 - Earliest claimed: 2020-01-31 - Assignees: Phoenix Instinct Ltd - Applicants: Phoenix Instinct Ltd - Inventors: ANDREW MACKAY SLORANCE - Web page: https://patentgrep.com/patent/US20230056464A1 ## CPC - A61G 5/02: propelled by the patient or disabled person - A61G 5/042: {Front wheel drive} - A61G 5/048: {Power-assistance activated by pushing on hand rim or on handlebar} - A61G 5/107: {positioning the whole seat forward or rearward} - A61G 5/1089: {Anti-tip devices} - A61G 5/10: Parts, details or accessories - A61G 5/1043: {Cushions specially adapted for wheelchairs} - A61G 5/1054: {Large wheels, e.g. higher than the seat portion} - A61G 2203/34: for pressure - A61G 2203/38: for torque - A61G 2203/42: for inclination - A61G: TRANSPORT, PERSONAL CONVEYANCES OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS (appliances for aiding patients or disabled persons to walk A61H3/00); OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES (embalming corpses A01N1/00) ## Abstract An advanced manually propelled wheelchair (100) is described. The wheelchair (100) has a chassis (110). In certain examples this may be a single piece design. The wheelchair (100) may further have one or more of a load adjustment mechanism (150) and a power-assist mechanism. The load adjustment mechanism (150) is configured to adjust a position of a set of rear wheels (120) for the wheelchair (100) relative to a loading of the wheelchair (100). Load adjustment may be performed based on a sensed loading. The power-assist mechanism provides a powered torque to a set of front wheels (130) to help a user propel the wheelchair (100) or to stabilise the wheelchair (100) during use. The power-assist mechanism may be provided as a set of modular front wheel units. ## Claims ### Claim 1 A manually propelled wheelchair comprising: a chassis to accommodate a seat; a set of rear wheels for manual propulsion arranged either side of the chassis; a set of front wheels; one or more sensors to detect a loading of the wheelchair; and a load adjustment mechanism to adjust a position of the set of rear wheels relative to the seat in response to signals from the one or more sensors. ### Claim 2 (depends on 1) The wheelchair of claim 1, wherein the set of rear wheels are moveable and wherein the load adjustment mechanism is configured to adjust a position of the set of rear wheels. ### Claim 3 (depends on 1) The wheelchair of claim 1,wherein the load adjustment mechanism is configured to adjust a position of the seat within the chassis. ### Claim 4 (depends on 1) The wheelchair of claim 1, wherein the one or more sensors comprise one or more sensors to detect a load applied to one or more of the set of front wheels. ### Claim 5 (depends on 4) The wheelchair of claim 4, wherein the load adjustment mechanism comprises: a controller to receive the signals from the one or more sensors and instruct an adjustment to the position of the set of rear wheels relative to the seat, wherein the controller is configured to detect a reduction in the load applied to one or more of the front wheels and in response instruct movement of one of the seat and the set of rear wheels in a first direction along the axis between the set of front wheels and the set of rear wheels, and wherein the controller is configured to detect an increase in the load applied to one or more of the front wheels and in response instruct movement (or relative adjustment of the position) (preferably relative to the chassis) of one of the seat and the set of rear wheels in a second direction along the axis between the set of front wheels and the set of rear wheels, the second direction being opposite to the first direction. ### Claim 6 (depends on 1) The wheelchair of claim 1, wherein the one or more sensors comprise one or more pressure sensors arranged relative to the seat to detect a load applied to the seat. ### Claim 7 (depends on 1) The wheelchair of claim 1, wherein the load adjustment mechanism comprises one or more of: a first mechanism to move (or adjust the position of) the seat relative to the chassis along the axis between the set of front wheels and the set of rear wheels; and a second mechanism to move (or adjust the position of) the set of rear wheels relative to the chassis along the axis between the set of front wheels and the set of rear wheels. ### Claim 8 (depends on 1) The wheelchair of claim 1, wherein the seat comprises a removeable cushion that is mounted within the chassis. ### Claim 9 (depends on 7) The wheelchair of claim 7, wherein the chassis is formed as a single piece. ### Claim 10 (depends on 1) The wheelchair of claim 1, wherein the load adjustment mechanism comprises an override mechanism to prevent an adjustment of the position of the set of rear wheels relative to the seat. ### Claim 11 (depends on 1) The wheelchair of claim 1, comprising: one or more orientation sensors to determine an orientation of the seat, wherein the load adjustment mechanism is modulated by input from the one or more orientation sensors. ### Claim 12 (depends on 1) The wheelchair of claim 1, comprising: a power-assist system for the set of front wheels, wherein the power-assist system comprises at least one motor coupled to one or more of the set of front wheels, wherein a torque applied to one or more of the set of front wheels by the at least one motor assists the manual propulsion of the wheelchair using the set of rear wheels. ### Claim 13 (depends on 12) The wheelchair of claim 12, wherein each wheel within the set of front wheels is rotatable about a steering axis perpendicular to an axis of rotation for the wheel. ### Claim 14 (depends on 13) The wheelchair of claim 13, comprising: a directional control system to steer the wheelchair using at least the set of front wheels, wherein the load adjustment mechanism is configured to increase a load upon the set of front wheels to enable the directional control system and the power-assist system to propel the wheelchair when a load is absent from the seat (and/or when the load upon the front wheels is below a pre-determined threshold). ### Claim 15 (depends on 12) The wheelchair of claim 12, wherein the load adjustment mechanism is configured to adjust a load upon the set of front wheels dependent on the torque applied by the power assist system. ### Claim 16 A method of operating a manually propelled wheelchair comprising: sensing a change in a centre of gravity for the wheelchair at least along an axis between a set of front wheels and a set of rear wheels, wherein the set of rear wheels are manually propelled to move the wheelchair; and adjusting a relative position of the set of rear wheels compared to a seat of the wheelchair based on the change, the seat being configured to receive a load for the wheelchair. ### Claim 17 (depends on 16) The method of claim 16, wherein sensing a change in a centre of gravity comprises sensing a load applied through one or more of the set of front wheels, and wherein adjusting a relative position of the set of rear wheels compared to a seat of the wheelchair comprises moving one of the set of rear wheels and the seat of the wheelchair based on the load. ### Claim 18 (depends on 16) The method of claim 16, wherein adjusting a relative position of the set of rear wheels compared to a seat of the wheelchair comprises moving one or more axles coupled to the set of rear wheels relative to a chassis of the wheelchair. ### Claim 19 A manually propelled wheelchair comprising: a chassis to accommodate a seat; a pair of rear wheels for manual propulsion arranged either side of the chassis; a pair of front wheels; and a drive system for the pair of front wheels, wherein the drive system comprises at least one motor coupled to the pair of front wheels, and wherein a torque applied to one or more of the set of front wheels by the at least one motor at least assists the propulsion of the wheelchair. ### Claim 20 (depends on 19) The wheelchair of claim 19, comprising: a directional control system to adjust a direction of the wheelchair by instructing a differential torque to be applied to one or more of the set of front wheels, wherein the drive system and the directional control system enable remote control of the wheelchair when a load is absent from the seat. ### Claim at position 21 21-25. (canceled)