WO2021222800A1

WO2021222800A1 - Motorized caster assembly for manual wheelchair

Info

Publication number: WO2021222800A1
Application number: PCT/US2021/030253
Authority: WO
Inventors: Lance FERGUSON; Maximilian FRANTZ; Trent L. CARPENTER; Anthony Bryant; Robert Lukasiewicz
Original assignee: Koyo Bearings North America Llc
Priority date: 2020-04-30
Filing date: 2021-04-30
Publication date: 2021-11-04
Also published as: WO2021222800A9

Abstract

A motorized caster assembly for use with a wheelchair having a frame with a pair of front members, and a front caster attached to each, the assembly includes a platform, at least one drive caster attached to the platform, at least one electric motor, the at least one electric motor being operatively connected to a corresponding one of the at least one drive caster so that the corresponding caster is selectively driveable by the at least one electric motor, and an attachment device, wherein the attachment device secures the motorized caster assembly to the front members wheelchair.

Description

TITLE

MOTORIZED CASTER ASSEMBLY FOR MANUAL WHEELCHAIR

CLAIM OF PRIORITY

[0001] This application claims priority to U.S. provisional patent application number

63/018,049 filed April 30, 2020 and U.S. provisional patent application number 63/047,758 filed July 2, 2020, the disclosures of which are incorporated by reference herein.

TECHNICAL FIELD

[0002] The presently-disclosed invention relates generally to wheelchairs and, more specifically, to a device to provide assistance in propulsion of a user.

BACKGROUND

[0003] Add-on power assist devices for wheelchairs are known. However, existing devices tend to be bulky and fairly complicated when it comes to attaching the devices to the corresponding wheelchair. As well, not only are the existing power assist devices difficult to attach, they are often difficult to remove when not needed. The issues of excess bulk and difficulty attachment/removal can make transporting the corresponding wheelchair impractical when necessary.

[0004] There at least remains a need, therefore, for power assist devices for wheelchairs that are lighter and less bulky than present devices, and provide increased functionality. SUMMARY OF THE INVENTION

[0005] One embodiment of the present invention provides a motor caster assembly for use with a wheelchair having a frame, a foot rest, and at least one front caster, the assembly includes a platform, at least one caster, at least one electric motor, the at least electric motor being operatively connected to a corresponding one of the at least one caster so that each caster is selectively driveable by the corresponding electric motor, and an attachment device, wherein the attachment device secures the motor caster assembly to the wheelchair.

[0006] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS [0007] The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not, all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

[0008] Figure 1 is a rear perspective view of a motorized caster assembly, in accordance with an embodiment of the present invention, for use with a manual wheelchair;

[0009] Figure 2 is a perspective view of a prior art wheelchair including the motorized caster assembly shown in Figure 1 attached thereto;

[0010] Figures 3A through 3E are partial cross-sectional views of various attachment assemblies, taken along line 3-3 of Figure 2, in accordance with the present invention; [0011] Figure 4 is a perspective view of a prior art wheelchair including a motorized caster assembly in accordance with an alternate embodiment of the present invention;

[0012] Figure 5 is a rear perspective view of a motorized caster assembly in accordance with an alternate embodiment of the present invention;

[0013] Figure 6 is a perspective view of a prior art wheelchair including the motorized caster assembly shown in Figure 5 attached thereto;

[0014] Figure 7 is a perspective view of a prior art wheelchair including a motorized caster assembly in accordance with an alternate embodiment of the present invention attached thereto;

[0015] Figures 8A and 8B are perspective views of motorized caster assemblies in accordance with alternate embodiments of the present invention;

[0016] Figure 9 is a perspective view of a prior art wheelchair including a motorized caster assembly in accordance with an alternate embodiment of the present invention attached thereto;

[0017] Figures 10A through 10E are perspective views of motorized caster assemblies in accordance with alternate embodiments of the present invention, each showing an alternate method for attachment to a corresponding wheelchair;

[0018] Figure 11 is a perspective view of a prior art wheelchair including the motorized caster assembly shown in Figure 10A attached thereto;

[0019] Figure 12 is a schematic of an input control device in the form of a joystick assembly in accordance with an embodiment of the present invention;

[0020] Figure 13 is a schematic of an input control device in the form of a fob in accordance with an embodiment of the present invention; and [0021] Figure 14 is a block diagram of an example motorized caster assembly in accordance with an embodiment of the present invention.

[0022] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention according to the disclosure.

DETAILED DESCRIPTION

[0023] The invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not, all embodiments of the invention are shown. Indeed, this invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements.

[0024] As used herein, terms referring to a direction or a position relative to the orientation of the fuel-fired heating appliance, such as but not limited to "vertical," "horizontal," "upper," "lower," "above," or "below," refer to directions and relative positions with respect to the appliance's orientation in its normal intended operation, as indicated in the Figures herein. Thus, for instance, the terms "vertical" and "upper" refer to the vertical direction and relative upper position in the perspectives of the Figures and should be understood in that context, even with respect to an appliance that may be disposed in a different orientation.

[0025] Further, the term "or" as used in this disclosure and the appended claims is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless specified otherwise, or clear from the context, the phrase "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, the phrase "X employs A or B" is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from the context to be directed to a singular form. Throughout the specification and claims, the following terms take at least the meanings explicitly associated herein, unless the context dictates otherwise. The meanings identified below do not necessarily limit the terms, but merely provided illustrative examples for the terms. The meaning of "a," "an," and "the" may include plural references, and the meaning of "in" may include "in" and "on." The phrase "in one embodiment," as used herein does not necessarily refer to the same embodiment, although it may.

[0026] Referring now to the Figures, an embodiment of a motorized caster assembly 100 in accordance with the present invention is shown in Figure 1. The motorized caster assembly 100 includes a center platform 102, a pair of side flanges 104, and a pair of sidewalls 106, each sidewall 106 extending upwardly from a corresponding side edge of the center platform 102 to a corresponding one of the side flanges 104. Each side flange 104 is configured to removably receive a motorized caster 130. Additionally, one or more attachment assemblies 108 extend outwardly from a rear edge 103 of the center platform 102 so that the motorized caster assembly 100 may be removably secured to a prior art wheelchair 10. As best seen in Figure 11, a prior art wheelchair 10 may include a frame 12 supported on a pair of manual drive wheels 14 that are connected by an axle 16, and a pair of non-driven caster 20. Each caster is rotatable received in a corresponding caster support leg 18 of the frame 12. Additionally, a footrest assembly 24 is typically supported by footrest support legs 22 of the frame 12.

[0027] As best seen in Figure 10A, each motorized caster 130 preferably includes a base

132 with a threaded stem 134 extending upwardly therefrom. Each threaded stem 134 extends upwardly through an aperture (not shown) formed in a corresponding side flange 104 of the motorized caster assembly 130. The threaded steam 134 extends through a lower bearing 136 that is disposed between an upper surface of the base 132 and a bottom surface of the side flange 104, as well as through an upper bearing 138 that is adjacent the top surface of the side flange 104. A pressure ring 140 secures the motorized caster 130 to the corresponding side flange 104 and provides a pre-load on the upper bearing 138 and the lower bearing 136. A fork 142 is pivotably mounted to the base 132 at a first edge of the fork 142, and is secured at an opposing edge to the base 132 by a pair of springs 144. As shown, springs 144 urge the fork 142 to pivot downwardly so that the associated wheel 150 of the motorized caster 130 maintains contact with the support surface on which the wheelchair 10 rests. The wheel 150 of the motorized caster 130 is rotatably received on an axle 148 that is supported in a yoke 146 at the bottom end of the fork 142. Preferably, the wheel 150 of each motorized caster 130 includes an internal motor (not shown) and receives power through a slip ring (not shown) so that the fork 142 and, therefore, the wheel 150 is continuously rotatable about the vertical axis of the motorized caster 130.

[0028] Referring now to Figures 1, 2, and 3 A, the motorized caster assembly 100 is removably secured to the footrest assembly 24 of the wheelchair 10. As shown, the footrest assembly 24 of the prior art wheelchair 10 includes a U-shaped support bracket 26 including a pair of vertical elongated members 28 extending upwardly from opposite ends of a horizontal elongated member 30. An upper end of each vertical elongated member 28 is received within a bottom end of a corresponding tubular footrest support leg 22, and a footrest platform 34 is supported on the horizontal elongated member 30. As best seen in Figure 3A, the motorized caster assembly 100 is secured to the horizontal elongated member 30 of the footrest’s U-shaped support bracket 26 by passing the horizontal elongated member 30 between an upper plate 110 and a lower plate 112 of each attachment assembly 108. Preferably, the upper plate 110 and the lower plate 112 are substantially parallel to each other, and each plate includes an aperture 111 formed therein. The pair of apertures 111 are configured to receive a bolt 114 therethrough. As shown, the bolt 114 has a head 116 and threaded stem 118 extended therefrom. A threaded nut 120 is utilized to secure the bolt 114 in place so that the horizontal elongated member 30 of the footrest’s U-shaped support member 26 is secured between the rear edge 103 of the center platform 102 and the threaded stem 120 of the bolt 114.

[0029] As best seen in Figure 2, with the motorized caster assembly 100 secured in place, the footrest platform 34 of the footrest assembly 24 is disposed adjacent the top surface of the center platform 102 of the motorized caster assembly 100. As such, the footrest platform 34 prevents the motorized caster assembly 100 from rotating upwardly about the horizontal elongated member 30 since it is rigidly secured to the horizontal elongated member 30. As shown in Figure 2, and discussed in greater detail below, control of the motorized caster assembly 100 is provided by way of an input control device 400 in the form of a joystick 402, that provides input to electronics housed in an electronics enclave 401 that is secured to the frame 12. As shown, wired connections 403 are provided although wireless embodiments are also disclosed.

[0030] Referring now to Figure 3B, an alternate embodiment of an attachment assembly is shown. The attachment assembly 160 includes a substantially U-shaped bracket 161 and a threaded fastener 16. As shown, the rear edge 103 of the center platform 102 of the motorized caster assembly 100 is disposed adjacent to the horizontal elongated member 30 of the footrest assembly 24. The U-shaped bracket 161 is positioned so that the horizontal elongated member 30 is disposed between the curved portion 162 of the U-shaped bracket 161 and the rear edge 103 of the center platform 102. With the U-shaped bracket 161 in this position, apertures defined in both the top wall 163 and the bottom wall 164 of the U-shaped bracket 161 are aligned with a bore 165 that passes through the center platform 102. The elongated stem 166 of the threaded fastener is passed through both the apertures of the U-shaped bracket 161 and the bore 165 of the center platform 102 and secured therein by a threaded nut 167 that engages the elongated stem 166. Note, rather than using a rigid metal bracket as discussed above, the bracket may be replaced by a flexible strap comprised of a material such as, but not limited to, metal, nylon, rubber, polyvinylchloride, etc.

[0031] Referring now to Figure 3C, an alternate embodiment of an attachment assembly

170 in accordance with an embodiment of the present invention as shown. The attachment assembly 170 includes a flexible strap 171 formed of a material such as, but not limited to, metal, nylon, rubber, etc., that is affixed at a proximal end 172 to the rear edge 103 of the center platform 102 of the motorized caster assembly 100. An aperture defined in its distal end 173.

As shown, the flexible strap 171 is used to secure the horizontal elongated member 30 of the footrest assembly 24 adjacent to the rear edge 103 of the center platform 102. The horizontal elongated member 30 is secured in this position by passing a threaded stem 174 of the fastener through the aperture in the strap 171 and engaging a threaded bore 175 formed in the center platform 102 of the motorized caster assembly 100.

[0032] Referring now Figure 3D, an alternate embodiment of an attachment assembly

180 in accordance with the present invention is shown. Attachment assembly 180 includes one or more hooked portions 181 that extend rearwardly from the rear edge 103 of the center platform 102 of the motorized caster assembly 100. Each hooked portion 181 is configured to receive the horizontally elongated member 30 of the footrest assembly 24 between itself and the rear edge 103 of the center platform 102. Although the hooked portion 181 is not secured to the horizontal elongated member 30 by any further fasteners, the motorized caster assembly 100 remains in place as it is prevented by rotating upwardly by the footrest platform 34 of the footrest assembly 24. In short, the footrest platform 34, which is rigidly secured to the horizontal elongated member 30 of the U-Shaped bracket 24, prevents the horizontal elongated member 30 from moving downwardly out of engagement with the hooked portion 181 as the footrest platform 34 is adjacent the top surface of the center platform 102. Although the hooked portion 181 allows the motorized caster assembly 100 to rotate downwardly, it can only do so when the motorized caster assembly 100 is elevated above the corresponding support surface and, therefore, not supporting any weight.

[0033] Referring now to Figure 3E, an alternate embodiment of an attachment assembly

190 in accordance with the present disclosure as shown. The attachment assembly 190 includes a pair of opposed tabs 191, each tab 191 being attached to the rear edge 103 of the center platform 102 at the top and bottom surfaces thereof. As shown, each tab 191 includes a camming surface 192 that is configured to urge the tabs 191 away from each other as the camming surfaces 192 are engaged by the horizontal elongated member 30 of the footrest assembly 24. To mount the motorized caster assembly 100 to the horizontal elongated member 30, a user pushes the motorized caster assembly 100 toward the horizontal elongated member 30 so that the horizontal elongated member 30 engages both camming surfaces 192 simultaneously. This interaction will cause the resilient tabs 191 to move away from each other until the horizontal elongated member 30 passes therethrough, at which point the resilient tabs 191 are allowed to return to their original positions, which is shown in Figure 3E. Preferably, the inner surface 193 of each tab 191 is configured to prevent the tabs 191 from moving apart as the horizontal elongated member 30 is urged against those surfaces. To remove the motorized caster assembly 100 from the footrest assembly 24, the user merely urges the resilient tabs 191 apart by hand.

[0034] Referring now to Figure 4, a wheelchair 10 including a motorized caster assembly

100 including an alternate embodiment of an attachment assembly 200 in accordance with the present invention. As in the previously discussed embodiments, the motorized caster assembly 100 is removably secured to the footrest assembly 24 of the wheelchair 10. As shown, straps 202 and 204 of hook and loop fastening material are used to secure the motorized caster assembly 100 to the footrest assembly 24. Specifically, each of the attachment assemblies 200 includes a first strap 202 having a proximal end affixed to the front edge 105 of the center platform 102 of the motorized caster assembly 100 and a second strap 204 having a proximal end affixed to the rear edge 103 of the center platform 102. Preferably, to provide a more secure attachment, the pairs of straps 202 and 204 are secured to the center platform 102 such that when they are engaged with each other, the horizontal elongated member 30 is adjacent the rear edge 103 of the center platform 102 and the footrest platform 34 is disposed between an upper surface of the center platform 102 and the engaged straps 202 and 204. This configuration of attachment assembly 200 can prove very useful for shorter periods of time in which a user desires to secure the motorized caster assembly to the wheelchair 10.

[0035] Referring now to Figures 5 and 6, an alternate embodiment of a motorized caster assembly 100a in accordance with the present invention is shown. The motorized caster assembly 100a differs only from the embodiment discussed above with regard to Figure 1 in that motorized caster assembly 100a does not include attachment assemblies configured to secure the motorized caster assembly 100a to the footrest assembly 24 (Figure 1) of the wheelchair 10. As such, the same reference numbers have been used to indicate identical components of the two embodiments. Rather than the previously discussed attachment assemblies, motorized caster assembly 100a includes a support bracket 220 that is preferably fixed to the rear edge 103 of the center platform 102 of the body portion 101, such as by welding. As shown, the support bracket 220 includes a horizontal elongated member 222 fixed to the rear edge 103 of the center platform 102, and a pair of vertical elongated members 224 extending upwardly from opposite ends of the horizontal elongated member 222. A top end 226 of each vertical elongated member 224 is configured to be slidably received within a corresponding footrest support leg 22 of the frame 12 of the wheelchair 10. Note, in alternate embodiments, the upper portions 226 of the vertical elongated members 224 may be tubular so that the bottom ends of the footrest support legs 22 may be slidably received therein. Note, the entire footrest assembly 24 (Figure 2) is removed from the wheelchair 10 to allow the motorized caster assembly 100a to be mounted to the frame 12. As such, the center platform 102 of the motorized caster assembly 100a functions as a footrest for a user of the wheelchair 10. Referring additionally to Figure 7, an embodiment of the motorized caster assembly 100a is shown in which the electronics enclosure which houses various electrical components, batteries, etc., is mounted to the center platform 102 of the body portion 101 rather than the frame 12 of the wheelchair 10. As well, the user input device is in the form of a fob 500 that allows for wireless communication with the electronics of the motorized caster assembly 100a.

[0036] Referring now to Figures 8 A, 8B, and 9, alternate embodiments of motorized caster assemblies in accordance with the present invention are shown. These alternate embodiments differ primarily from the previously discussed embodiments in how the assemblies are secured to the frame 12 of the wheelchair 10. Specifically, referring to Figures 8A, motorized caster assembly 100b includes a pair of upwardly-extending projections 210, each one disposed on a corresponding side flange 104 of the body portion 101. Each projection 210 is configured to be slidably received within a tubular bottom portion of a corresponding caster support leg 18 of the frame 12 of the wheelchair 10. As shown in Figure 9, motorized caster assembly 100a differs from the embodiment shown in Figure 8 in that the upwardly-extending projections 212 are tubular so that the bottom end portions of the caster support legs 18 are slidably received therein. As shown in Figures 8 A and 8B, the electronics enclosure 401 is supported on the center platform 102. However, as shown in Figure 9, when the electronics enclosure 401 is mounted to the frame 12, the footrest assembly 24 may remain connected to the frame 12.

[0037] Referring now to Figure 10A, an alternate embodiment of a motorized caster assembly 500 in accordance with the present invention is shown. The motorized caster assembly 500 includes a bottom platform 502, a side flange 504, and a sidewall 506 extending upwardly from a side edge of the bottom platform 502 to the side flange 504. The side flange 504 is configured to removably receive a motorized caster 130. Additionally, an attachment assembly 520 is disposed on the bottom platform 502 so that the motorized caster assembly 500 may be removably secured to a prior art wheelchair 10, as shown in Figure 11.

[0038] As shown in Figure 10A, the attachment assembly 520 includes a mounting plate

522 with one or more threaded stems 524 extending downwardly therefrom. An aperture 526 is formed in the bottom plate 502 for each threaded stem 524. To mount the motorized caster assembly 500 to a wheelchair 10, the top surface of the bottom plate 502 is disposed adjacent the bottom surface of the footrest platform 34. Next, the elongated stems 524 of the mounting plate 522 are passed through corresponding slots 32 of the footrest platform 34 and apertures 526 of the bottom plate 502 of the motorized caster assembly 500. Threaded nuts 528 are tightened onto the correspondingly threaded elongated stems 524, thereby securing the motorized caster assembly 500 to the footrest assembly of the wheelchair 10.

[0039] Referring now to Figure 10B, the motorized caster assembly 500a shown differs only from the embodiment shown in Figure 10A in that the threaded elongated stems 524 extend upwardly from the bottom plate 502 and the mounting plate 522 includes the corresponding apertures 528. As shown in Figure IOC, in an alternate embodiment of a motorized caster assembly 500b, the mounting plate 522 shown in Figure 10B may be omitted with only the threaded elongated stems 524 on corresponding nuts 528 engaging the footrest platform 34. [0040] Referring now to Figure 10D, a motorized caster assembly 500c in accordance with an alternate embodiment of the present invention is shown. Motorized caster assembly 500c includes an attachment assembly in the form of a mounting flange 540 that is integrally formed along the front edge of the bottom mounting 502. The mounting flange 540 is parallel to the bottom platform 502 so that a gap 542 is formed therebetween. To mount the motorized caster assembly 500c to a corresponding wheelchair 10, the user simply slides the front portion of the footrest platform 34 (Figure 10A) unto the gap 542 so that the top surface of the bottom platform 502 is adjacent the bottom surface of the footrest platform 34.

[0041] Referring now to Figure 10E, a motorized caster assembly 500d in accordance with the present invention is shown. Motorized caster assembly 500d includes an attachment assembly 560 in the form of straps 562 and 564 of hook and loop fastening material that are used to secure the motorized caster assembly 100 to the footrest assembly 24. Specifically, the attachment assembly 560 includes a first strap 562 having a proximal end affixed to the front edge 503 of the bottom platform 502 of the motorized caster assembly 500d and a second strap 564 having a proximal end affixed to the rear edge 503 of the bottom platform 502. The first and the second straps 562 and 564 are configured to secure the footrest platform 34 between the bottom platform 502 and the engaged straps. This configuration of attachment assembly 560 can prove very useful for shorter periods of time in which a user desires to secure the motorized caster assembly to the wheelchair.

[0042] Figure 12 shows an example implementation of a user input assembly of a motorized caster assembly system according to various example embodiments in the form of a joystick assembly 400. The joystick assembly 400 may be one example of a user input assembly that includes a deflection sensor and a lever. The joystick assembly 400 is operable communication with the motorized caster assembly 100 assembly, via, for example, the processor as described with respect to Figure 14. Joystick assembly 400 includes a lever 410 that can pivot about an axis (as indicated by the arrows) in response to movement of, for example, a vertical joystick. Joystick assembly 400 further includes a support base and a deflection sensor. The deflection sensor may measure the deflection of the lever 410 and provide an indication of the deflection to, for example, processor. A corresponding steering input signal having an indication of both a direction of turn and a rate of drive may be ultimately provided to an actuator (e.g., steering actuator 315 of Figure 14) via a wired or a wireless connection. Note, a single user input assembly, such as one joystick assembly 400, may be used to provide control input signals to both motorized casters of the discussed embodiments. However, in alternate embodiments, each motorized caster may receive control input signals from its own joystick assembly 400 so that each motorized caster is operable independently of the other motorized caster.

[0043] According to some example embodiments, the measured deflection of the lever

410 is an indication of the desired direction and rate of drive for the motorized caster assembly 100. In this regard, a user may cause the lever 410 to deflect by an angle (according to example coordinate system 431) by manipulating the joystick 402 and the angle may be measured (e.g., in degrees) by the deflection sensor. The rate of drive may be a function of the magnitude of the angle measured by the deflection sensor 440. In this regard, with each increase of an angle of deflection, the rate of drive may also increase, for example, proportionally based on a linear or exponential function. For example, if the lever 410 is deflected by 5 degrees from a given origin, then the rate of drive may be half that of the rate of drive if the deflection angle is 10 degrees. [0044] Figure 13 provides another example user input assembly that includes a deflection sensor and a lever. Fob 500 may be an embodiment of a control device that includes, for example, the processor described with respect to Figure 14. The user input assembly of the fob may include rocker button that pivots about axis. The rocker button 510 may form the lever of some example embodiments and a deflection of the rocker button 510 may be measured by a deflection sensor (not shown). With respect to operation, a user may depress the desired portion of the rocker button 510 to cause the rocker button 510 to deflect from its origin position. The angle of deflection may be measured by the deflection sensor and communicated to the processor as both a direction and rate of drive. As described above, increases in the angle of deflection can result in increased rates of drive.

[0045] According to some example embodiments, a change with respect to time in the angle of deflection may alternatively be used to indicate a desired rate of drive. In this regard, if a lever rapidly moves from, for example, an origin position to a given angle of deflection, then the rate of drive would be higher. For example, with respect to the joystick assembly 400, if a user was to rapidly move the joystick 402 to generate a rapid change in the angle of deflection as measured by the deflection sensor 440 with respect to time, then a high rate of drive may be determined by the processor 335 (Figure 14). Likewise, if a user slowly changes the angle of deflection, then the processor 335 may determine a lower rate of drive. In a similar fashion, the rate of change of the angle of the deflection of the rocker button 510 may be monitored to determine a rate of drive for provision to a steering actuator. As such, the processor 335 may be configured to determine a rate of drive based on the rate at which and angle of deflection changes with respect to time.

[0046] Referring again to Figure 12, in some embodiments, the foot pedal 410 may include pressure sensors 450 and 451 (e.g., in combination with or as an alternative to deflection sensor 440). Accordingly, as a user manipulates the joystick 402, thereby causing the lever 410 to contact the pressure sensor. As such, a pressure (or force) is applied to the sensor and the sensor measures the pressure. If pressure is applied to element 450, then a rate of drive in a first direction may be determined, and if pressure is applied to the element 451, then a rate of drive in the opposite direction may be determined. In a similar manner, pressure sensors may be used in conjunction with the fob 500 to measure the pressure applied to various portions of the rocker button 510 to determine a rate of drive.

[0047] Referring again to Figure 12, in some embodiments, instead of pressure sensors, elements 450 and 451 may be switches. In such an example embodiment, as a user depresses the lever 410 onto the switch by way of manipulating the joystick 402, the switch may transition to an active state. Further, a user may hold the lever 410 in that position for a duration of time.

The duration of time may be measured and as it increases, the rate of drive may increase. In other words, holding the lever 410 down longer by way of the joystick 402 can cause the rate of drive to increase. In a similar manner, switches may be used in conjunction with the fob 500 and a duration of time in an active state may be measured on the rocker button 510 to determine a rate of drive.

[0048] Figure 14 shows a block diagram of a motorized caster assembly 100 in communication with an input control device 330. As described herein, it is contemplated that while certain components and functionalities of components may be shown and described as being part of the motorized caster assembly 100, the sonar assembly, or the input control device 330, according to some example embodiments, some components (e.g., functionalities of the processors 305 and 335, or the like) may be included in the other of the motorized caster assembly 100 or the input control device 330. As depicted in Figure 14, the motorized caster assembly 100 may include a processor 305, a memory 310, a drive actuator 315, a drive motor 320, and a communication interface 325.

[0049] The processor 305 may be any means configured to execute various programmed operations or instructions stored in a memory device such as a device or circuitry operating in accordance with software or otherwise embodied in hardware or a combination of hardware and software (e.g., a processor operating under software control or the processor embodied as an application specific integrated circuit (ASIC) or field programmable gate array (FPGA) specifically configured to perform the operations described herein, or a combination thereof) thereby configuring the device or circuitry to perform the corresponding functions of the processor 305 as described herein. In this regard, the processor 305 may be configured to analyze electrical signals communicated thereto, for example in the form of a drive input signal received via the corresponding communication interface 325, and instruct the drive actuator 315 to rotate the drive motor 320 in accordance with a received direction and rate of drive. [0050] The memory 310 may be configured to store instructions, computer program code, drive motor steering codes and instructions, and other data in a non-transitory computer readable medium for use, such as by the processor 305. The communication interface 325 may be configured to enable connection to external systems. In this manner, the processors 305 may retrieve stored data from remote, external servers via the communication interface 325 in addition to or as an alternative to the memory 310.

[0051] The processor 305 of motorized caster assembly 100 is in communication with and control the drive actuator 315. The drive actuator 315 may be an electronically controlled mechanical actuator (i.e., an electro-mechanical actuator) configured to actuate at various rates (or speeds) in response to respective signals or instructions. The drive actuator 315 may be configured to rotate the drive motor 320, in response to electrical signals. To do so, steering actuator 315 may employ a solenoid, a motor, or the like configured to convert an electrical signal into a mechanical movement. Preferably, each caster 130 (Figure 1) of the motorized caster assembly 100 includes a drive motor that is internal to the hub of the caster’s wheel.

[0052] According to some example embodiments, an autopilot navigation assembly 326 may be configured to determine a destination (e.g., via input by a user) and route for a wheelchair and control the drive actuator 315, via the processor 305, to steer the drive motor 320 in accordance with the route and destination. In this regard, the processor 305 and memory 310 may be considered components of the autopilot navigation assembly 326 to perform its functionality, but the autopilot navigation assembly 326 may also include position sensors. The memory 310 may store digitized charts and maps to assist with autopilot navigation. To determine a destination and route for a watercraft, the autopilot navigation assembly 326 may employ a position sensor, such as, for example, a global positioning system (GPS) sensor. Based on the route, the autopilot navigation assembly 326 may determine that different rates of drive may be needed to efficiently move along the route to the destination. As such, the autopilot navigation assembly 326 may instruct the steering actuator 315, via the processor 305, to turn in accordance with different rates of drive as defined in a planned route. According to some example embodiments, a rate of drive during a route may be a function of, for example, the grade of the support surface, condition of the support surface, traffic in the immediate area, etc.

[0053] As mentioned above, the motorized caster assembly 100 is in communication with a input control device 330 that is configured to selectively control the operation of both the motorized caster assembly 100. In this regard, the navigation control device 330 may include a processor 335, a memory 340, a communication interface 345, and a user input assembly 350. The processor 335 may be any means configured to execute various programmed operations or instructions stored in a memory device such as a device or circuitry operating in accordance with software or otherwise embodied in hardware or a combination of hardware and software (e.g., a processor operating under software control or the processor embodied as an application specific integrated circuit (ASIC) or field programmable gate array (FPGA) specifically configured to perform the operations described herein, or a combination thereof) thereby configuring the device or circuitry to perform the corresponding functions of the processor 335 as described herein. In this regard, the processor 335 may be configured to analyze signals from the user input assembly 350 (joystick assembly 400, fob 500, etc.) and convey the signals or variants of the signals, via the communication interface 345 to either the motorized caster assembly 100. [0054] The memory 340 may be configured to store instructions, computer program code, trolling motor steering codes and instructions, marine data, such as sonar data, chart data, location/position data, and other data in a non-transitory computer readable medium for use, such as by the processor 335. The communication interface 345 may be configured to enable connection to external systems (e.g., communication interfaces 325). In this manner, the processor 335 may retrieve stored data from a remote, external server via the communication interface 345 in addition to or as an alternative to the memory 340.

[0055] Communication interfaces 325 and 345 may be configured to communicate via a number of different communication protocols and layers. For example, the link between the communication interfaces 325 and communication interface 345 may be any type of wireless communication link. For example, communications between the interfaces may be conducted via Bluetooth, Ethernet, the NMEA 2000 framework, cellular, WiFi, or other suitable networks. [0056] According to various example embodiments, the processor 335 may operate on behalf of the motorized caster assembly 100, and the input control device 330. In this regard, the processor 335 may be configured to perform some or all of the functions described with respect to processors 305, and processor 335 may communicate directly to the autopilot navigation assembly 326 and the drive actuator 315 directly via a wireless communication.

[0057] The processor 335 may also interface with the user input assembly 350 to obtain information including both a direction and a rate of drive for the motorized caster assembly 100 based on user activity that are one or more inputs to the user input assembly 350. In this regard, the processor 335 may be configured to determine the direction and rate of drive based on user activity detected by the user input assembly 350, and generate a steering/directional input signal. The steering/directional input signal may be an electrical signal indicating both the direction and rate of drive. Specifically, the processor 335 is configured to direct the drive/directional actuator 315 directly or indirectly, to rotate the drive motor 320 at a desired rate of drive based on the rate of drive indicated in the input signal. According to some example embodiments, the processor 335 may be further configured to modify the rate of drive indicated in the drive/directional input signal to different values based on variations in the user activity detected by the user input assembly 350.

[0058] Various example embodiments of a user input assembly 350 may be utilized to detect the user activity and facilitate generation of a drive input signal indicating a rate of drive. To do so, various sensors including feedback sensors, and mechanical devices that interface with the sensors, may be utilized. For example, a deflection sensor 355, a pressure sensor 365, or a switch 366 may be utilized as sensors to detect user activity with respect to a rate of drive.

[0059] According to some example embodiments, a deflection sensor 355 and a lever

360 may be utilized as the user input assembly 350. The deflection sensor 355 may be any type of sensor that can measure an angle of deflection of an object, for example, a lever 360 from a center or zero position. In this regard, the processor 335 may be configured to determine a desired rate of drive based on an angle of deflection (e.g., from a set point or origin) of the lever 360 measured by the deflection sensor 355. For example, as a user increases the angle of deflection, for example, from an origin, a rate of drive for the direction of drive may also increase thereby implementing a variable rate of drive for the propulsion direction.

[0060] According to some embodiments, rather than using techniques that measure an angle of deflection, a pressure sensor 365 may be used in conjunction with, for example, either the lever 360 or a push button 370 to determine a rate of turn. In this regard, the pressure sensor 365 may be configured to detect an amount of pressure applied on the pressure sensor by a user and provide a pressure value to the processor 335 based on the detected amount of pressure. In turn, the processor 335 may be configured to determine a rate of drive based on the pressure value. According to some example embodiments, higher detected amounts of pressure may indicate a higher rate of drive. The rate of drive may have a linear or exponential relationship to the pressure value.

[0061] According to some example embodiments, a rate of drive may be alternatively be determined based on a duration of time that a switch, such as switch 366, is in an active position. In this regard, switch 366 may have two states an active state (e.g., “on”) and an inactive state (e.g., “off’)· According to some example embodiments, switch 366 may normally be in the inactive state and user activity, such as actuation of the lever 360 or the push button 370, may be required to place the switch 366 in the active state. When in the active state, a duration of time in the active state may be detected and the rate of turn may be a function of the duration of time that the switch 366 is in the active state.

[0062] In yet further alternate embodiments, load sensors may be used to detect the presence of a user in the wheelchair. The processor may use the information about whether or not a user is present in the seat to automatically power up/down the system, apply brakes, or prevent the chair from moving without user input. Furthermore, load sensing may detect a state in which the user is transferring from the wheelchair to another chair and actively brake to prevent the wheelchair from moving during the transfer. The addition of a hill hold mode could detect the user's intent to move up a slope, and actively apply brakes to prevent the user from rolling backwards down the hill between pushrim inputs.

[0063] In yet other alternate embodiments, a user-selectable mode could either decrease the assist level or actively resist user input for the purpose of strength training so that the user can exercise the motor skills and capacity required to use a wheelchair. As well, the addition of a forward vision system camera(s), radar, LiDaR, etc., an automatic emergency braking (AEB) system could automatically slow or stop the chair when a forward collision is predicted by the controller. A surface detection sensor may dynamically scale the level of assist based on the detected road/ground surface. Knowing the surface, the system could automatically switch to a higher or lower assist level to best match the inherent resistance of the current road/ground surface. Additionally, embodiments could include circuitry that could send current to recharge the battery when the motor was being driven by gravity, strength training pushes, caretakers, etc. [0064] The wireless capabilities of various embodiments could allow a user to send remote commands to the motors of the casters in order to maneuver the chair remotely (e.g., to send the chair away once the user has transferred out of the chair, the retrieve the chair from downhill if the chair has rolled away from the user, etc.). Sensing and processing capabilities to automatically seek out a charging station may also be included in alternate embodiments. Moreover, the addition of a microphone and processing capability could accept voice commands (e.g., "faster", "slower", "power down", etc.). Embodiments could include selectable presets for different terrains and surfaces. These presets may be communicated to the device through a wired or wireless means. For example, a user may want different presets for carpet vs. concrete. [0065] These and other modifications and variations to the invention may be practiced by those of ordinary skill in the art without departing from the spirit and scope of the invention, which is more particularly set forth in the appended claims. For example, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and it is not intended to limit the invention as further described in such appended claims. Therefore, the spirit and scope of the appended claims should not be limited to the exemplary description of the versions contained herein.

Claims

1. A motorized caster assembly for use with a wheelchair having a frame with a pair of front members, and a front caster attached to each, the assembly comprising: a platform; at least one drive caster attached to the platform; at least one electric motor, the at least one electric motor being operatively connected to a corresponding one of the at least one drive caster so that corresponding caster is selectively driveable by the at least one electric motor; and an attachment device, wherein the attachment device secures the motorized caster assembly to the front members wheelchair.

2. The motorized caster assembly of claim 1, wherein the at least one drive caster is secured to a center portion of the platform.

3. The motorized caster assembly of claim 1, wherein the at least one drive caster further comprises a pair of drive casters, each drive caster being secured to an opposing end of the platform.

4. The motorized caster assembly of claim 1, further comprising a battery configured to provide power to the at least one electric motor of the at least one corresponding drive caster, wherein the battery is disposed within an internal cavity of the platform.

5. The motorized caster assembly of claim 4, wherein the attachment device comprises a pair of elongated shafts, each elongated shaft being disposed within an open bottom end of a corresponding front member of the frame of the wheelchair.