The application is generally related to wheelchairs and, in particular, to assemblies for propelling the wheelchair.
The most common form of a manual wheelchair 100 utilizes a push rim 110 connected directly to the drive wheels 120 as shown in
The positioning of the push-rim/wheel 110/120 combination in common wheelchairs leads to difficulties in transfers (transferring in and out of the wheelchair 100). For example, the user must position the wheelchair at an angle with a bed 200 or other transfer surface in order to use a transfer board 210 (see
Moreover, conventional wheelchairs comprise a single push rim on each side that is coupled to the respective drive wheel at a fixed gear ratio. Accordingly, a balance must be set between the force required to push the single push rim and the number of revolutions of the single push rim. In order to keep the force required to push the push rim in a manageable range to allow the user to push the wheelchair uphill and across difficult terrain, the wheelchair is typically configured with a push rim that requires a significantly high number of rotations for movement across easy flat terrain. This can lead to excessive arm movement cycles that, over time, can lead to injury of the user (often to her shoulders).
Some manual wheelchairs have been adapted with specialized wheels which add a gear between the tire and hand rim in order to allow shifting between normal gear ratio to lower gear for going up inclines or rough terrain, but the wheelchair must be stopped to change gears. Stopping to change gears results in loss of momentum of the wheelchair. Thus, the user is required to restart the wheelchair from a full stop, with resultant loss of efficiency.
Described herein, in various aspects, is a wheelchair comprising a frame and a drive wheel coupled to the frame. The drive wheel can be configured to rotate relative to the frame about a first axis of rotation. A first push rim can be coupled to the frame. The first push rim can be configured to rotate relative to the frame about a second axis of rotation that extends parallel or substantially parallel to the first axis of rotation. A second push rim can be coupled to the frame. The second push rim can be configured to rotate relative to the frame about a third axis of rotation that extends parallel or substantially parallel to the first axis of rotation. A transmission can be configured to transmit rotation of each of the first and second push rims to the drive wheel to effect rotation of the drive wheel. Movement of the first push rim by a first arc length can be configured to cause the drive wheel to rotate by a first angular displacement, and movement of the second push rim by the first arc length is configured to cause the drive wheel to rotate by a second angular displacement that is greater than the first angular displacement.
Additional advantages will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the disclosed wheelchair, systems, and/or methods. The advantages will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
These and other features of the preferred embodiments of the disclosed wheelchair, systems, and methods will become more apparent in the detailed description in which reference is made to the appended drawings wherein:
The present 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. Like numbers refer to like elements throughout. It is to be understood that this invention is not limited to the particular methodology and protocols described, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention.
Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
As used herein the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. For example, use of the term “a wheel” can refer to one or more of such wheels, and so forth.
All technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs unless clearly indicated otherwise.
As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.
As used herein, the term “at least one of” is intended to be synonymous with “one or more of.” For example, “at least one of A, B and C” explicitly includes only A, only B, only C, and combinations of each.
Ranges can be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint. Optionally, in some aspects, when values are approximated by use of the antecedents “about,” “substantially,” or “generally,” it is contemplated that values within up to 15%, up to 10%, up to 5%, or up to 1% (above or below) of the particularly stated value can be included within the scope of those aspects. In other aspects, when angular values are approximated by use of the antecedents “about,” “substantially,” or “generally,” it is contemplated that angular values within up to 15 degrees, up to 10 degrees, up to 5 degrees, or up to one degree (above or below) of the particularly stated angular value can be included within the scope of those aspects.
The word “or” as used herein means any one member of a particular list and also includes any combination of members of that list.
In the following description and claims, wherever the word “comprise” or “include” is used, it is understood that the words “comprise” and “include” can optionally be replaced with the words “consists essentially of” or “consists of” to form another embodiment.
It is to be understood that unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is in no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; and the number or type of aspects described in the specification.
The following description supplies specific details in order to provide a thorough understanding. Nevertheless, the skilled artisan would understand that the apparatus, system, and associated methods of using the apparatus can be implemented and used without employing these specific details. Indeed, the apparatus, system, and associated methods can be placed into practice by modifying the illustrated apparatus, system, and associated methods and can be used in conjunction with any other apparatus and techniques conventionally used in the industry.
Disclosed herein, in various aspects and with reference to
In this implementation, the wheelchair 400 includes a frame 405, a rotatable push rim 410 connected to the frame 405 and a drive wheel 420 connected to the frame 405. The wheelchair 400 may also include caster wheels 440 located in front of the drive wheel 420. The caster wheels 440 and the drive wheels 420 collectively form the base of support 435 of the wheelchair. In order to provide a stable ride for the user, it may be preferable that caster wheels 440 and the drive wheels be positioned such that the user's center of gravity 430 is located directly above the base of support 435, rather than in front of or behind the base of support 435.
As shown in
Thus, de-coupling the fore-aft position of the push rims 410 and drive wheels 420 may allow a clinician to place the drive wheels 420 in their optimal position to provide a stable base of support 435 while still allowing the person to do “wheelies” (e.g., with one or more wheels off the ground) if needed (to go over curbs and other thresholds). Also, the position of the push rims 410 can be set to promote the best positioning of the wheelchair user's shoulders. A potential aspect of this more forward positioning of the push rims 410 is a reduction in shoulder pain resulting from manual propulsion of the wheelchair. In other words, de-coupling of the push rims 410 and drive wheels 420 may allow the clinician to place the push rims 420 in front of the user's center of gravity 430 as shown in
Additionally, the use of the transmission 460 with the belts or chains 490 may allow the wheelchair to also incorporate into one or both of the drive gear/hub 450 and the push rim gear/hub 470 a multispeed fixed-gear hub such as the Sturmey-Archer S3X fixed-gear hub. In such implementations, the ability to switch to higher or lower speeds may allow the wheelchair user to go faster on smooth/even terrain and to require less torque and forces on the shoulders to go up inclined terrain.
Additionally, in some implementations, the wheelchair 400 also includes a push rim repositioning member 480 that allows the push rim 410 to be repositioned to allow a user to transfer into and out of wheelchair 400 without having to lift himself over the push rim as shown in
Additionally, in some optional embodiments, a locking mechanism 483 may be provided to releasably hold the push rim repositioning member 480 (e.g., swing arm) in the propulsion position shown in
Though various aspects of this embodiment are shown in the figures and discussed above, implementations of this embodiment and application are not limited to these aspects, and, accordingly, alternative implementations are discussed below.
As with the implementation discussed above, in this implementation, the wheelchair 500 includes a frame 505, a rotatable push rim 510 connected to the frame 505, and a drive wheel 520 connected to the frame 505. The wheelchair 500 may also include caster wheels 540 located in front of the drive wheel 520. Again, the caster wheels 540 and the drive wheels 520 collectively form the base of support 535 of the wheelchair. In order to provide a stable ride for the user, it may be preferable that caster wheels 540 and the drive wheels 520 be positioned such that the user's center of gravity 530 is located directly above the base of support 535, rather than in front of or behind the base of support 535.
As shown in
Again, de-coupling the fore-aft position of the push rims 510 and drive wheels 520 may allow a clinician to place the drive wheels 520 in their optimal position to provide a stable base of support 535 while still allowing the person to do “wheelies” if needed (to go over curbs and other thresholds). Also, the position of the push rims 510 can be set to promote the best positioning of the wheelchair user's shoulders. A potential aspect of this more forward positioning of the push rims 510 is a reduction in shoulder pain resulting from manual propulsion of the wheelchair. In other words, de-coupling of the push rims 510 and drive wheels 520 may allow the clinician to place the push rims 520 in front of the user's center of gravity 530 as shown in
Again, the use of the transmission 560 with the belts or chains 590 may allow the wheelchair to also incorporate, into either one or both of the drive gear/hub 550 and the push rim gear/hub 570, a multi-speed fixed-gear hub such as the Sturmey-Archer S3X fixed-gear hub, for example. In such implementations, the ability to switch to higher or lower speeds may allow the wheelchair user to go faster on smooth/even terrain and to require less torque and forces on the shoulders to go up inclined terrain.
Additionally, in some implementations, the wheelchair 500 also includes a push rim repositioning member 580 that allows the push rim 510 to be repositioned to allow a user to transfer into and out of wheelchair 500 without having to lift himself over the push rim as shown in
Though various aspects of this embodiment are shown in the figures and discussed above, implementations of this embodiment and application are not limited to these aspects and, accordingly, alternative implementations are discussed below.
By incorporating a push rim reposition member, such as shown in the implementations of
This implementation shown in
As shown in
Again, de-coupling the fore-aft position of the push rims 710 and drive wheels 720 may allow a clinician to place the drive wheels 720 in their optimal position to provide a stable base of support while still allowing the person to do “wheelies” if needed (to go over curbs and other thresholds). Also, the position of the push rims 710 can be set to promote the best positioning of the wheelchair user's shoulders. A potential aspect of this more forward positioning of the push rims 710 is a reduction in shoulder pain resulting from manual propulsion of the wheelchair. In other words, de-coupling of the push rims 710 and drive wheels 720 may allow the clinician to place the push rims 720 in front of the user's center of gravity as shown in
Again, the use of the transmission with the belts or chains 790 may allow the wheelchair to also incorporate a multi-speed fixed-gear hub to provide the ability to switch to higher or lower speeds and thereby allow the wheelchair user to go faster on smooth/even terrain and to require less torque and forces on the shoulders to go up inclined terrain.
Additionally, in some implementations, the wheelchair 700 also includes a push rim repositioning member 780 that allows the push rim 710 to be repositioned to allow a user to transfer into and out of wheelchair 700 without having to lift himself over the push rim as shown in
Additionally, in some implementations, a locking mechanism (not shown) may be provided to releasably hold the push rim 710 (e.g., swing arm) in the propulsion position located in front of the user's shoulders as shown in
Though various aspects of this embodiment are shown in the figures and discussed above, implementations of this embodiment and application are not limited to these aspects and, accordingly, alternative implementations are discussed below.
In the implementations discussed above, the push rim is shown as being movable between a propulsion position and a transfer position. However, implementations of the present invention need not have only two positions. Instead, a wheelchair according to the present application may include a push rim repositioning mechanism configured to allow customizable placement of the push rim based on a user's specific physical dimensions and/or physical capabilities and/or the activities in which the patient is involved.
Further optional aspects of wheelchairs in accordance with embodiments disclosed herein are disclosed in U.S. Patent Publication No. 2019/0133854 to Hansen et al., filed May 5, 2015, the entirety of which is hereby incorporated by reference herein.
With reference to
A second push rim 1110b can be coupled to the frame 1105. The second push rim 1110b can be configured to rotate relative to the frame 1105 about a third axis of rotation 1127b that extends parallel or substantially parallel to the first axis of rotation 1125. Optionally, as shown in
As shown in
As stated herein, the first and second push rims 1110a,b can be configured to provide different torque advantages. For example, movement of the first push rim 1110a by a first arc length can cause the corresponding drive wheel 1120 rotatably coupled thereto to rotate by a first angular displacement, and movement of the second push rim by the first arc length can cause the corresponding drive wheel to rotate by a second angular displacement that is greater than the first angular displacement. As should be understood, an arc length can be a length along the circumference of the push rim (e.g., one foot).
Optionally, and with reference to
In further aspects, it is contemplated that the different diameters of the first and second push rims 1110a,b can provide different torque advantages. For example, in some aspects, the first and second push rims 1110a,b can be fixedly coupled to each other so the first push rim does not rotate relative to the second push rim. As used herein, “fixedly coupled” should be understood to describe an arrangement in which a first component is coupled to or associated with a second component so that rotation of the first component by an angular displacement causes corresponding rotation of the second component by the same angular displacement. Such arrangements can include any direct or indirect mechanical connection or linkage that ensures that rotation and angular displacement of the first component effects a corresponding rotation of the second component by the same angular displacement. Accordingly, a user pushing the push rim having the larger diameter (e.g., the first push rim) by a first arc length can cause the corresponding drive wheel to rotate by a first angular displacement, whereas the user pushing the push rim having the smaller diameter (e.g., the second push rim) by the same arc length can cause the drive wheel to move by a second arc length that is greater than the first arc length.
Referring to
Such a configuration, with first push rim 1110a comprising the ring gear 1172 and the carrier 1178 coupled to the second push rim 1110b, can provide a gear ratio between the first push rim 1110a and second push rim 1110b of about 1:1 to about 1:2. For example, in some optional aspects, the gear system can provide a ratio of 2:3 so that a rotation of the second push rim corresponds to 1.5 rotations of the first push rim. It is further contemplated that first push rim 1110a can comprise the ring gear 1172, and the sun gear 1174 can be coupled to the second push rim 1110b, with the carrier 1178 fixedly coupled to the frame. It is contemplated that this configuration can provide a gear ratio between the first push rim 1110a and second push rim 1110b of less than or equal to 1:2 (optionally, about 1:4). That is, the described gear configuration can provide gearing in which the second push rim rotates at least two rotations for each rotation of the first push rim.
In various aspects, the first push rim 1110a can rotate relative to the drive wheel 1120 at a ratio of about 1:1 (revolution to revolution). In still further aspects, the second push rim 1110b can rotate relative to the drive wheel at a ratio of about 1:1 (revolution to revolution). In yet further aspects, the second push rim 110b can rotate relative to the drive wheel 1120 at a ratio of about 2:3 (revolution to revolution). In various aspects, each of the first push rim 1110a and the second push rim 1110b can rotate relative to the drive wheel 1120 at a ratio of between 3:1 and 3:5 (revolutions to revolutions). For example, optionally, the first push rim 1110a can rotate relative to the drive wheel 1120 at a ratio of between about 1:1 and about 3:5, and the second push rim 1110b can rotate relative to the drive wheel at a ratio of between about 3:1 and about 1:1. In still further aspects, the first and second push rims 1110a, 1110b can couple to the drive wheel 1120 with respective torque advantages. In some aspects, the torque advantage of the first push rim 1110a can be greater than the torque advantage of the second push rim 1110b. In some optional aspects, the first push rim 1110a can couple to the drive wheel 1120 with a torque advantage of greater than 1:1. In some optional aspects, the second push rim 1110b can couple to the drive wheel 1120 with a torque advantage of less than 1:1. With these different torque advantages, the higher torque advantage (the first push rim) can facilitate movement over difficult terrain, movement uphill, acceleration from a stop, and other movements that require high torque, whereas the lower torque advantage (second push rim) can be used across easier terrain, downhill, or after the wheelchair has begun movement. Accordingly, the user can initially start from a stop by pushing the first push rim 1110a and can then switch to the second push rim 1110b to maintain momentum. In still further aspects, the second push rim 1110b can advantageously be used to provide additional resistance for exercise.
Referring to
In some optional aspects, the push rim sprocket 1164 and the drive wheel sprocket 1166 can provide a torque advantage. For example, the pair of sprockets can provide a sprocket ratio (i.e., the ratio of the teeth of the push rim sprocket to the number of teeth of the drive wheel sprocket) that is greater than, less than, or equal to one, depending on the desired torque advantage to be provided.
Referring also to
It is contemplated that the overall torque advantage of the push rims can be determined as the ratio of (a) the rotation of a push rim by a given arc length to (b) the arc length of the rotation of the corresponding drive wheel. Accordingly, if the first push rim 1110a has a diameter that is 1.5 times the size of the drive wheel, and the sprocket ratio between the first push rim and the drive wheel is 1:1, the overall torque advantage of the first push rim is 1.5, so that pushing the first push rim by an arc length of 1.5 feet causes the drive wheel to rotate with an arc length of 1 foot. If the sprocket ratio is not 1:1, the torque advantage can be multiplied by the sprocket ratio. Thus, for a sprocket ratio in which the push rim sprocket 1164 has twice the number of teeth as the drive wheel sprocket 1166, the sprocket ratio can be 1:2. Thus, if the first push rim 1110a has a diameter that is 1.5 times the size of the drive wheel, and the sprocket ratio is 1:2, then the overall torque advantage of the first push rim can be 0.75. That is, pushing the first push rim by an arc length of 0.75 feet causes the drive wheel to rotate with an arc length of 1 foot. Accordingly, for the embodiment shown in
For embodiments in which the second push rim is coupled to the first push rim by a gear system, the torque advantage of the second push rim, TA2 can be calculated as TA2=D_PR2/D_DW*ns1/ns2*GR, wherein where D_PR2 is the diameter of the push rim, D_DW is the diameter of the drive wheel, n_s1 is the number of teeth on the drive wheel sprocket, n_s2 is the number of teeth on the push rim sprocket, and GR is the gear ratio between the first push rim and the second push rim. Thus, for example, if the gear ratio of the first push rim to the second push rim is 2:3, with the sprocket ratio of 1:2, and with the second push rim having a diameter equal to 0.8 times the diameter of the drive wheel, the torque advantage of the second push rim can be 0.8*1/2*2/3, or 0.267.
Referring to
It is contemplated that the wheelchair 1100 can weigh less than 29 pounds, thereby qualifying as an ultralight wheelchair. In further aspects, the wheelchair 1100 can weigh less than 35 pounds (e.g., 34 pounds). Optionally, the wheelchair 1100 can weigh less than 35 pounds (e.g., 34 pounds) with both sets of first and second push rims 1110a,b attached, and the wheelchair can weigh less than 29 pounds with only the pair of first push rims 1110a attached (and the second push rims 1110b removed).
Although not shown in the Figures, it is further contemplated that the epicyclic gearing can be positioned so that the ring gear is coaxial with the drive wheel, and the first and second push rims 1110a,b can couple to the epicyclic gearing via, for example, respective sprockets and belts or chains.
In still further aspects, it is contemplated that the gear system 1170 can be omitted. Rather, the first and second push rims 1110a,b can drive respective axles that can be coaxial. Each axle can be coupled to a respective sprocket. Each of the sprockets of the axles of the first and second push rims 1110a,b can be coupled to a respective sprocket that is fixedly coupled to the axle of the drive wheel. The ratio of the number of teeth of the sprocket of the axle of the first push rim 1110a to the teeth of the respective sprocket of the axle can be different from the ratio of the number of teeth of the sprocket of the axle of the second push rim 1110b to the teeth of the respective sprocket of the axle. In this way, the first and second push rims 1110a,b can rotate at different angular rates relative to each other. Accordingly, it is contemplated that the cost and complexity of gearing can be avoided. However, omission of gears in favor of separate sprockets for each push rim can, in some circumstances, add to the weight of the wheelchair.
Although the foregoing wheelchair, systems, and methods have been described in some detail by way of illustration and example for purposes of clarity of understanding, certain changes and modifications may be practiced within the scope of the appended claims.
The application claims priority to and the benefit of the filing date of U.S. Provisional Patent Application No. 63/155,544, filed Mar. 2, 2021, the entirety of which is hereby incorporated by reference herein.
Number | Date | Country | |
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63155544 | Mar 2021 | US |