Abstract
Disclosed are provisions for enabling a user of a wheelchair to rapidly outfit a first side of the wheelchair with a first implement or a second implement, both implements having adaptive functionalities, and also for enabling the user to perform the same in conjunction with a second side of the wheelchair. Useful implements include those having: A.) ground-contacting functionalities, such as improving navigation over rough terrain and adding forward stability to the wheelchair, and B.) non-ground-contacting elevated functionalities, including holding an umbrella, carrying an electronic device, or supporting a tray, work surface, or other auxiliary load.
Claims
1. An implement system for a wheelchair, the wheelchair comprising a first forward lateral portion and a pair of primary caster wheels, the pair of primary caster wheels capable of supporting a forward portion of a load carried by the wheelchair, the implement system comprising a first fixed mount adapted to be disposed on the first forward lateral portion of the wheelchair, the first fixed mount comprising a first fixed coupling member, the first fixed mount further adapted to couple with a first releasable coupling member in a first instance and with a second releasable coupling member in a second instance, the implement system adapted for: I. Coupling, in the first instance, of the first releasable coupling member with the first fixed coupling member, and coupling, in the second instance, of the second releasable coupling member with the first fixed coupling member; II. Operation of an elevated type implement, connected to one of the first releasable coupling member or the second releasable coupling member, during interposition of the first implement between the wheelchair and an auxiliary load, the elevated type implement being capable of supporting the auxiliary load while maintaining the auxiliary load in a predetermined position; III. Operation of a ground-contacting type implement, connected to one of the first releasable coupling member or the second releasable coupling member, during interposition of the second implement between the wheelchair and a ground surface beneath the wheelchair, the ground-contacting type implement being capable of rotation about a substantially horizontal rotation axis to a predetermined deployed position.
2. The implement system of claim 1 being adapted for deployment of the elevated type implement in a first predetermined position relative to the first forward lateral portion of the wheelchair, the implement system being further adapted for deployment of the ground-contacting type implement in a second predetermined deployed position relative to the first forward lateral portion of the wheelchair.
3. The implement system of claim 1, wherein the ground-contacting type implement is capable of supporting a forward portion of a load carried by the wheelchair and wherein, during deployment, the ground-contacting type implement maintains the wheelchair in a modified load-bearing configuration having the pair of primary caster wheels of the wheelchair substantially relieved from supporting the forward portion of the load carried by the wheelchair.
4. The implement system of claim 1, the fixed mount being capable of supporting a first load placed thereupon in a first direction, the fixed mount being further capable of supporting a second load placed thereupon in a second direction.
5. The implement system of claim 1 enabling connection of a first elevated type implement to the first forward lateral portion of the wheelchair and connection of a second elevated type implement to a second, symmetrically-opposing forward lateral portion of the wheelchair.
6. The implement system of claim 1 enabling connection of an elevated type implement to the first forward lateral portion of the wheelchair and connection of a ground-contacting type implement to a second, symmetrically-opposing forward lateral portion of the wheelchair.
7. The implement system of claim 1 enabling connection of a first ground-contacting type implement to the first forward lateral portion of the wheelchair and connection of a second, symmetrically-opposing ground-contacting type implement to a second, symmetrically-opposing forward lateral portion of the wheelchair.
8. The implement system of claim 7 being capable of effectuating simultaneous deployment of the first ground-contacting type implement and the second, symmetrically-opposing ground-contacting type implement.
9. The implement system of claim 1, the first fixed mount comprising a bearing post, at least one of the first releasable coupling member or the second releasable coupling member comprising a rotary latch mechanism comprising a pivotable latch element, the pivotable latch element capable of pivoting about a pivot axis toward and away from a holding position having the bearing post captured by the pivotable latch element.
10. The implement system of claim 9 wherein, while the bearing post is captured by the pivotable latch element, relative rotation is substantially inhibited between the first fixed mount and one of the first releasable coupling member or the second releasable coupling member.
11. The implement system of claim 1 being capable of maintaining the first releasable coupling member in a lateral position along a substantially horizontal line of insertion relative to the first fixed coupling member while the first releasable coupling member is coupled to the first fixed coupling member, the implement system being further capable of maintaining the second releasable coupling member in the lateral position along the substantially horizontal line of insertion relative to the first fixed coupling member while the second releasable coupling member is coupled to the first fixed coupling member.
12. The implement system of claim 1 being capable of maintaining at least one of the first releasable coupling member or the second releasable coupling member in a position along a substantially horizontal line of insertion, the substantially horizontal line of insertion being substantially parallel to the substantially horizontal rotation axis passing through the rotary joint of the second implement.
13. The implement system of claim 1 being capable of maintaining at least one of the first releasable coupling member or the second releasable coupling member in a position along a substantially horizontal line of insertion, the substantially horizontal line of insertion being substantially perpendicular to the substantially horizontal rotation axis passing through the rotary joint of the second implement.
14. The implement system of claim 1 being capable of coupling the first releasable coupling member to the first fixed coupling member in a direction along a first substantially horizontal lateral line of insertion passing through the first fixed coupling member.
15. The implement system of claim 14 being further capable of coupling a symmetrically-opposing releasable coupling member, disposed on a symmetrically-opposing implement, to a symmetrically-opposing fixed coupling member, the symmetrically-opposing fixed coupling member disposed on a symmetrically-opposing fixed mount disposed on a symmetrically-opposing forward lateral portion of the wheelchair, in a direction along a second, substantially horizontal line of insertion passing through the symmetrically-opposing fixed coupling member.
16. The implement system of claim 15, the symmetrically-opposing fixed mount, the symmetrically-opposing releasable coupling member, and the symmetrically-opposing implement each being of mirror image form respective to the first fixed mount, the first releasable coupling member, and a first implement.
17. An implement system for a wheelchair, the wheelchair comprising a pair of primary caster wheels, the implement system comprising a fixed coupling member adapted to be disposed on a first forward lateral portion of the wheelchair, the fixed coupling member capable of removably coupling with a first implement in an elevated capacity during a first instance of use wherein, during interposition between the wheelchair and an auxiliary load, the first implement is capable of supporting an auxiliary load while maintaining the auxiliary load in a predetermined deployed position; the fixed coupling member further capable of removably coupling with a second implement in a ground-contacting capacity during a second instance of use, the fixed coupling member further capable of deploying the second implement about a substantially horizontal rotation axis to and from a predetermined deployed position wherein, during deployment of the second implement, the wheelchair is maintained in a modified load-bearing configuration having the pair of primary caster wheels substantially relieved from supporting a forward portion of a load carried by the wheelchair.
18. An implement system for a wheelchair, the implement system comprising a fixed coupling member adapted to be disposed on a first forward lateral portion of the wheelchair, the fixed coupling member further adapted for attachment and removal of one of a plurality of implements in an instance of use, at least one of the plurality of implements being capable of interposition between the wheelchair and an auxiliary load to enable a first implement to perform in an elevated capacity in a first instance of use, and at least one of the plurality of implements being capable of rotation about a substantially horizontal axis to a predetermined deployed position to enable a second implement to perform in a ground-contacting capacity in a second instance of use.
19. A wheelchair comprising a fixed coupling member integrated with a first forward lateral portion of the wheelchair, the fixed coupling member capable of attachment and removal of a first one of a plurality of implements in a first instance of use, the fixed coupling member further capable of attachment and removal of a second one of a plurality of implements in a second instance of use, the fixed coupling member further capable of removably coupling with an elevated type implement capable of being interposed between the wheelchair and an auxiliary load, the fixed coupling member further capable of removably coupling with a ground-contacting type implement capable of rotation about a substantially horizontal axis to and from a predetermined deployed position.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0076] FIGS. 1A and 1B illustrate a system capable of attaching and deploying a plurality of ground-contacting adaptive implements and a plurality of elevated type adaptive implements.
[0077] FIGS. 2A and 2B show a wheelchair capable of stowing dual ground-contacting adaptive implements beneath the seat of the wheelchair and attaching said adaptive implement above the rear axle, the dual ground-contacting adaptive implements capable of being attached and deployed to dual (left and right) front frame mounts disposed on the left and right sides of the front of the wheelchair (on the front down tubes of the wheelchair frame). FIGS. 2C and 2D show the wheelchair having the left-side caster wheel implement removed from the stowed location beneath the seat of the wheelchair and, at a location to the left of the wheelchair, ready for connection to the frame mount disposed on the left side of the front of the wheelchair.
[0078] FIGS. 3A-3D show close-up views which illustrate how the left-sided ground-contacting adaptive implement is capable of coupling with the left-sided front frame mount. FIG. 3E shows how the left-sided ground-contacting adaptive implement is capable of deploying in a rotary fashion and illustrates how the internal compression spring and spherical bearing are positioned during pre-deployment and deployment.
[0079] FIG. 4A shows the wheelchair having dual elevated type adaptive implements attached and deployed, with the front (primary) caster wheels of the wheelchair elevated from contact with the ground surface. FIGS. 4B and 4C show close-up views illustrating the coupling of the left-sided ground-contacting adaptive implement with the left-sided front frame mount.
[0080] FIG. 5A depicts an elevated work surface implement detached from the wheelchair frame and adjusted, via an adjustable locking hinge, in a folded configuration for ease of storage. The elevated work surface implement has an upwardly-deploying rotary latch mechanism assembly.
[0081] FIG. 5B depicts the elevated work surface implement attached to the right front down tube of the wheelchair frame and in a deployed position.
[0082] FIG. 5C illustrates the relative positioning of components of the upwardly-deploying rotary latch mechanism assembly during two distinct mechanism stages (pre-deployment and deployment).
[0083] FIG. 6A depicts an elevated utility holder implement, having a downwardly-deploying rotary latch mechanism assembly, detached from the wheelchair frame.
[0084] FIG. 6B depicts the elevated utility implement attached to the right front down tube of the wheelchair frame and in a deployed position. An umbrella is shown connected within a receptacle of the utility holder implement.
[0085] FIG. 6C illustrates the relative positioning of components of the downwardly-deploying rotary latch mechanism assembly during two distinct mechanism stages (pre-deployment and deployment).
[0086] FIG. 7A shows an example wherein the frame mounts are welded to the left and right front down tubes of the wheelchair frame, with the wheelchair having the left-side caster wheel implement ready for connection to the left-side frame mount, and with the right-side caster wheel implement ready for connection to the right-side frame mount.
[0087] FIG. 7B shows the dual caster wheel implements connected to the wheelchair presented in the first alternative embodiment presented in FIG. 7A, the dual caster wheel implements each assuming a deployed orientation.
[0088] FIGS. 8A-D show an example wherein the receivers are integrated into the left and right front down tubes of the wheelchair frame, the wheelchair capable of being outfitted with ground-contacting implements and elevated type implements.
[0089] FIGS. 9A-F show an example wherein an oval insert and receiver coupling arrangement is used for releasable connection of ground-contacting and elevated type implements.
DETAILED DESCRIPTION OF THE INVENTION
[0090] The drawings described hereinafter are intended for the purpose of illustration rather than limitation.
[0091] To facilitate understanding of the figures, when appropriate, structural elements located on the right side of the wheelchair as well as any attachments thereto, from the perspective of an occupant of the wheelchair, have been labeled with the suffix R following the numeral corresponding to the structural element. Similarly, when appropriate, structural elements located on the left side of the wheelchair and any attachments thereto have been labeled with the suffix L following the numeral corresponding to the structural element. In cases where the aforementioned labeling convention does not aid in understanding a particular figure, the suffix has been omitted and only the numeral has been used. For example, the left-side rear drive wheel is referred to by label 120L, and the right-side rear drive wheel is referred to by label 120R. However, in a side-view illustration wherein 120L cannot be visibly distinguished from 120R, the rear drive wheels are collectively referred to by using label 120. Similarly, in some illustrations, the figure may be sufficiently clear and easily understood without the need to distinguish between left-sided elements and right-sided ones; in such cases the L and R naming convention is not utilized.
[0092] FIGS. 1A and 1B present an embodiment of the invention that is operable as a system capable of transforming the wheelchair among a plurality of configurations such as those described above, including outfitting the wheelchair with ground-contacting adaptive implements as well as elevated type adaptive implements. In FIG. 1A, wheelchair 100A comprises frame 101, rear drive wheels 102L and 102R, axle 112, primary caster wheels 104L and 104R, front down tubes 106L and 106R, seat 108, and back support 110. Wheelchair 100A is outfitted with frame mount assemblies 120L and 120R clamped to forward front down tubes 106L and 106R of wheelchair 100A. Dual, symmetrically-opposing caster wheel implements 150L and 150R are shown deployed, with primary caster wheels 104L and 104R substantially elevated from contact with ground surface 10 beneath the wheelchair. Wheelchair 100B, which comprises the same elements as wheelchair 100A and which is outfitted with the same frame mount assemblies 120L and 120R, is shown having dual, symmetrically-opposing ski implements 160L and 160R deployed, with primary caster wheels 104L and 104R substantially elevated from contact with ground surface 10 beneath the wheelchair.
[0093] In FIG. 1B, wheelchair 100C, which comprises the same elements as wheelchairs 100A and 100B, is outfitted with frame mount assembly 120L clamped to forward front down tube 106L, without any frame mount assembly attached to opposing forward front down tube 106R. A single, upwardly-rotating elevated work surface implement 170 is shown deployed, with primary caster wheels 104L and 104R fully contacting ground surface 10. Wheelchair 100D, which comprises the same elements as wheelchairs 100A, 100B, and 100C, is outfitted with frame mount assembly 120R clamped to forward front down tube 106R, without any frame mount assembly attached to opposing forward front down tube 106L A single, downwardly-rotating elevated utility holder implement 180 is shown deployed, with primary caster wheels 104L and 104R fully contacting ground surface 10. Thus, wheelchairs 100A, 100B, 100C, and 100D, all comprising substantially similar structures and frame geometries, may be outfitted with one or both frame mount assemblies 120L and 120R to enable a variety of ground-contacting and elevated type functionalities.
[0094] FIG. 2A shows wheelchair 100A outfitted with frame mount assemblies 120L and 120R, with caster wheel implements 150L and 150R in a stowed position beneath the seat 108 and above the axle 112. FIG. 2B is rear view of the wheelchair, showing caster wheel implements 150L and 150R in the stowed position. Stowing clip 242L, fastened to stowing clip support 240L secures caster wheel implement 150L relative to the wheelchair 100A with substantial clearance between the caster wheel implement 150L and the ground surface 10. FIG. 2C is a rear view of the wheelchair, showing caster wheel implement 150R in the stowed position and opposing caster wheel implement 150L removed from the stowed position, thereby leaving stowing clip 242L unoccupied. FIG. 2D is a front view of wheelchair 100A having stowing clip 242L unoccupied and having caster wheel implement 150L ready for attachment to frame mount assembly 120L along insertion line 250.
[0095] In FIGS. 3A and 3B, caster wheel implement 150L, is shown ready for attachment to frame mount assembly 120L along insertion line 250. Caster wheel implement 150L comprises rotary latch mechanism assembly 352 connected to a first end of tubular arm 354. Connected to a second end of tubular arm is pivotable caster assembly 356.
[0096] FIG. 3C shows a close-up view of frame mount assembly 120L and its attachment to front down tube 106L using parallel clamp 310. Upon turning upper fastener 312A and lower fastener 312B clockwise, parallel clamp 310 secures adjustment support rod 320 in a vertical and rotational orientation; this arrangement permits adjustability of the orientation of the frame mount assembly 120L relative to the wheelchair, ultimately enabling adjustment of the deployed position of an attached implement, in this case the caster wheel implement 150L (not visible), relative to the wheelchair. Adjustment support rod 320 is rigidly fastened by upper fastener 322A and lower fastener 322B to support body 330. Bearing post 342 comprising retention flange 344 is rigidly fastened by bearing post fastener 346 to support body 330, with a desired distance of separation being maintained between bearing post 342 and support body 330 by spacer 340. Flanged sleeve bearing 332 having receptacle 334 is secured (press-fitted or cemented) within an aperture drilled or otherwise formed into support body 330. Receptacle 334 receives an insertion pin (shown in FIG. 3D); thus, flanged sleeve bearing 332 serves as a fixed coupling member capable of coupling with a releasable coupling member (the insert pin).
[0097] The close-up view of caster wheel implement 150L in FIG. 3D illustrates greater detail of caster wheel assembly 356 and rotary latch mechanism assembly 352, with tubular arm 354 interposed therebetween. Caster wheel assembly 356 comprises wheel 355 which is captivated within fork 358 by caster axle 359. Bearing housing 357 contains at least one rotary bearing (not visible) which permits rotation of the fork 358 about a caster pivot axis which is substantially vertical during deployment of caster wheel implement 150L. In order to achieve a vertical orientation of the caster pivot axis, angle adjustment joint 353 may be adjusted by way of loosening of fastener bolt 351, rotating fork 358 about a rotation axis passing through angle adjustment joint 353. Projecting though the body 370 of rotary latch mechanism assembly 352 is insertion pin 360, which is secured in position by spacer-clamp 362 on the inner side of the body 370 and by dome nut 364. Pivotable latch element 375, comprising handle end 376 and arcuate bearing surface 378, is captivated centrally within the body 370 and is capable of pivoting about a pivot axis defined by pin 377 projecting through the body 370 and the pivotable latch element 375. The body 370 comprises inner arcuate bearing surface 372 and outer arcuate bearing surface 374. The rotary latch mechanism assembly 352 further comprises striker projection 373 and arcuate bearing surface 378. Arcuate bearing surfaces 372, 374, and 378 are formed to have substantially the same radii as the radius of bearing post 342 (presented in FIG. 3C.).
[0098] Upon coupling of insertion pin 360 with receptacle 334 (presented in FIG. 3C.) and downward rotation of caster wheel implement 150L as a result of the user reclining the wheelchair 100A to substantially elevate primary caster wheels 104L and 104R, striker projection 373 contacts bearing post 342, with pivotable latch element 375 rotating inwardly, until downward rotation of caster wheel implement 150L relative to mount assembly 120L (and wheelchair 100) about insertion line 250 effectuates nesting of bearing post 342 against arcuate bearing surfaces 372 and 374 to stop further downward rotation of caster wheel implement 150L. Next, pivotable latch element 375 pivots outwardly to effectuate nesting of bearing post 342 against arcuate bearing surface 378 of pivotable latch element 375, accompanied by an audible click as pivotable latch element 375 quickly rotates back into its outermost orientation. Striker projection 373 now inhibits upward rotation of caster wheel implement 150L and maintains the wheelchair in a reclined orientation having primary caster wheels 104L and 104R (not visible) remaining elevated.
[0099] The action just described is further illustrated in FIG. 3E, which shows how the positioning of pivotable latch element 375 changes as caster wheel implement 150L is rotated downward (effectively decreasing the angle formed by the adjustment support rod 320 of mount assembly 120L and tubular arm 354 of the caster wheel implement 150L during transitioning from a pre-deployment stage to a deployment stage. Also indicated in FIG. 3E is spring 390 as it becomes deflected (compressed) upon inward rotation of pivotable latch element 375 during the pre-deployment stage. Force is transmitted between spring 390 and pivotable latch element 375 through sphere 392. Upon full downward rotation of tubular arm 354, pivotable latch element 375 is permitted to pivot outwardly, thereby permitting relaxation (extension) of spring 390.
[0100] By pushing inwardly against handle end 376 of pivotable latch element 375 to compress spring 390, the user is able to disengage the arcuate bearing surface 378 from bearing post 342, thereby permitting disengagement and upward rotation of the caster wheel implement 150L relative to the wheelchair 100A.
[0101] FIG. 4A shows the wheelchair having dual ground-contacting adaptive implements attached and deployed, with the front (primary) caster wheels of the wheelchair elevated from contact with the ground surface. FIGS. 4B and 4C show close-up views illustrating the coupling of the left-sided ground-contacting adaptive implement with the left-sided front frame mount.
[0102] For use of ground-contacting adaptive implements, such as caster wheels, omnidirectional wheels, or skis, downward rotation about a substantially horizontal rotation axis results in deployment of the ground-contacting adaptive implement in a predetermined position and orientation relative to the frame of the wheelchair and, in various embodiments, will also cause the front caster wheels of the wheelchair to become substantially elevated from contact with the ground surface, as indicated in FIG. 4A, wherein clearance gap 400 is created and maintained beneath the primary caster wheels 104L and 104R
[0103] As visible in FIGS. 4B and 4C, upon coupling of rotary latch mechanism assembly 352L with frame mount 120L, caster wheel implement 150L becomes substantially unified with front down tube 106L, in effect enabling the caster wheel implement 150L to behave as a forward extension of the wheelchair 100A and to support a forward portion of a load carried by the wheelchair 100A. Thus, while the caster wheel implement 150L is maintained in a predetermined deployed position, rotary latch mechanism assembly 352L serves as a load-bearing intermediary between the wheelchair 100A and the caster wheel implement 150L. The same is true of the rotary latch mechanism assembly 352R integrated with the symmetrically opposing caster wheel implement 150R (visible in FIG. 4A).
[0104] For use of some elevated type adaptive implements, such as a writing surface or an electronic device holder, it may be preferable to achieve deployment as a result of upward rotation thereof. In FIG. 5A, upwardly-deploying work surface implement 170 is shown detached from frame mount 120R (clamped onto wheelchair 100C) and folded into a collapsed configuration as a result of relative rotation of support plate 510 and curved arm 530 about a rotation axis passing through adjustable locking hinge 520. Adjustable locking hinge 520 is connected to a distal end portion of curved arm 530, whereas body 541 of upwardly-rotating latch assembly 540 is connected to a proximal end portion of curved arm 530. FIG. 5B shows upwardly-deploying work surface implement connected to wheelchair 100C via coupling of upwardly-rotating latch assembly 540 with frame mount 120R, said implement being maintained in a deployed orientation which enables an occupant of the wheelchair to utilize the work surface for activities such as writing, utilizing electronic devices, carrying a beverage, or for facilitating other activities of daily living.
[0105] Upon coupling of insertion pin 360 (not visible) with receptacle 334 (presented in FIG. 3C.) and upward rotation of work surface implement 170 as a result upward lifting thereof by the user, striker projection 373 contacts bearing post 342, with pivotable latch element 375 pivoting inwardly, until upward rotation of work surface implement 170 relative to mount assembly 120L (and wheelchair 100C) about insertion axis 250 (presented in FIGS. 2D and 3A) effectuates nesting of bearing post 342 against arcuate bearing surfaces 372 and 374 to stop further upward rotation of work surface implement 170. Next, pivotable latch element 375 rotates outwardly to effectuate nesting of bearing post 342 against arcuate bearing surface 378 of pivotable latch element 375, accompanied by an audible click as pivotable latch element 375 quickly rotates back into its outermost orientation as a result of urging force provided by spring 390. Striker projection 373 now inhibits downward rotation of work surface implement 170. By pushing inwardly against handle end 376 of pivotable latch element 375 to compress spring 390, the user is able to disengage the arcuate bearing surface 378 from bearing post 342, thereby permitting disengagement and downward rotation of the work surface implement 170 relative to the wheelchair 100C. FIG. 5C illustrates the relative positioning of the aforementioned elements of the upwardly-deploying rotary latch mechanism assembly, during the pre-deployment stage and during the deployment stage, in the case of an elevated type implement such as that illustrated in FIGS. 5A and 5B.
[0106] For use of some elevated type adaptive implements, such as an umbrella holder, a luggage or grocery carrier, or a medical device holder, it may be preferable to achieve deployment as a result of downward rotation thereof. In FIG. 6A, downwardly-deploying utility holder implement 180 is shown detached from frame mount 120R (clamped onto wheelchair 100D). Insert tube 610 is connected to a distal end portion of curved arm 630, whereas body 641 of downwardly-rotating latch assembly 640 is connected to a proximal end portion of curved arm 630. FIG. 6B shows downwardly-deploying utility holder implement 180 connected to wheelchair 100D via coupling of downwardly-rotating latch assembly 640 with frame mount 120R, said implement being maintained in a deployed orientation which enables an occupant of the wheelchair to utilize the utility holder implement 180 for purposes such as holding an umbrella (as illustrated in FIG. 6B).
[0107] Upon coupling of insertion pin 360 (not visible) with receptacle 334 (presented in FIG. 3C.) and downward rotation of utility holder implement 180 as a result of downward movement thereof enacted by the user, striker projection 373 contacts bearing post 342, with pivotable latch element 375 rotating inwardly, until downward rotation of utility holder implement 180 relative to mount assembly 120L (and wheelchair 100) about insertion axis 250 (presented in FIGS. 2D and 3A) effectuates nesting of bearing post 342 against arcuate bearing surfaces 372 and 374 to stop further downward rotation of utility holder implement 180. Next, pivotable latch element 375 rotates outwardly to effectuate nesting of bearing post 342 against arcuate bearing surface 378 of pivotable latch element 375, and may be accompanied by an audible click as pivotable latch element 375 quickly rotates back into its outermost orientation as a result of urging force provided by spring 390 against sphere 392. Striker projection 373 now inhibits upward rotation of utility holder implement 180. By pushing inwardly against handle end 376 of pivotable latch element 375 to compress spring 390, the user is able to disengage the arcuate bearing surface 378 from bearing post 342, thereby permitting disengagement and upward rotation of the utility holder implement 180 relative to the wheelchair 100A. FIG. 6C illustrates the relative positioning of the aforementioned elements of the downwardly-deploying rotary latch mechanism assembly, during the pre-deployment stage and during the deployment stage, in the case of an elevated type implement such as that illustrated in FIGS. 6A and 6B.
[0108] In FIG. 7A, frame mounts 720L and 720R are welded to the left and right front down tubes 106L and 106R of wheelchair 700, with the wheelchair having the left-side caster wheel implement 150L ready for connection to the left-side frame mount 720L, and with the right-side caster wheel implement 150R ready for connection to the right-side frame mount 720R. FIG. 7B shows the dual caster wheel implements connected to the wheelchair 700, with caster wheel implements 150L and 150R each assuming a deployed orientation and with primary caster wheels 104L and 104R substantially elevated from contact with ground surface 10 to form clearance gap 400 beneath primary caster wheels 104L and 104R.
[0109] FIG. 8A shows an example wherein double-pin receivers 830L and 830R are integrated into the left and right front down tubes of the wheelchair frame. In this illustration, the wheelchair has the left-side caster wheel implement 850L connected to the left front down tube 806L of wheelchair 800, right-side caster wheel implement 850R being ready for connection to the right front down tube 806R of wheelchair 800. Double pin structures 820L and 820R are used for the releasable connection of each caster wheel implement to double-pin receivers 830L and 830R integrated with the wheelchair frame, so that each pair of pins projects longitudinally through a front down tube during connection of implements to create a rigid union between each implement and the wheelchair frame, and so that minimal structure is left remaining on the wheelchair during disconnection of the implements.
[0110] FIG. 8B shows the example presented in FIG. 8A, with the wheelchair 800 having caster wheel implements 850L and 850R attached to wheelchair 800.
[0111] FIGS. 8C and 8D show the example presented in FIGS. 8A and 8B, utilized for connection of a multi-purpose elevated type attachment device 870 to right front down tube 806R of wheelchair 800, utilizing double-pin structure 854 to rigidly couple with double-pin receiver 830R along a longitudinal insertion axis projecting through front down tube 806L. Double-pin receiver 830L disposed on the left side of wheelchair 800 is shown unoccupied and having minimal structure protruding beyond the extents of front down tube 806L.
[0112] FIG. 9A shows an example having caster wheel implements 950L and 950R comprising oblong inserts 954L and 954R couple with oblong receivers 960L and 960R integrated within front down tubes 906L and 906R, respectively, for releasable connection of each caster wheel implement 950L and 950R, laterally, to the wheelchair. In this illustration, the left-side caster wheel implement and the right-side caster wheel implement are ready for connection to the left and right front down tubes.
[0113] FIGS. 9B and 9C show close-up views of the insert and the receiver of the example presented in FIG. 9A. Latching mechanism 958 of rotary latch mechanism assembly 952L is operatively interposed between oblong insert 954 and arm 980 of caster wheel implement 950. Outer body members 959A and 959B give support to latching mechanism 958 and isolate rotation of arm 980 of caster wheel implement 950 about rotation axis 920 passing through rotary joint 930. Spherical knob 990 is visible beneath rotary latch mechanism assembly 952L, and is attached to pivotable latch element 953. Forward pressure placed against spherical knob 990 by a user imparts movement of pivotable latch element 953 in order to disengage rotary latch mechanism assembly 952L from load-bearing and to permit free rotation of arm 980 about rotation axis 920 relative to oblong insert 954. Retractable locking pin assembly 970 is disposed on a rearward portion of front down tube 906L, and comprises pull ring 974 which, upon being pulled rearwardly by a user, draws retractable locking pin 972 (visible in FIG. 9C) sufficiently away to permit free insertion and removal of oblong insert 954 relative to oblong aperture 960L. Oblong insert 954 comprises locking pin aperture 956 through which retractable locking pin 972 is capable of projecting upon insertion of oblong insert 954 into oblong receptacle 960L to provide positive locking action for preventing accidental release of oblong insert 954 relative to oblong receptacle 960L.
[0114] FIG. 9D shows the example presented in FIG. 9A-C, with wheelchair 900 having both the left-side and right-side caster wheel implements attached, with clearance gap 400 formed beneath primary caster wheels 904L and 904R, which are shown substantially elevated from contact with ground surface 10.
[0115] FIGS. 9E and 9F show the example presented in FIG. 9A-D utilized for connection of multi-purpose elevated type attachment device 970 having oblong insert 954 which couples with oblong receiver 960R along an insertion axis projecting laterally through front down tube 906R. Oblong receiver 960L disposed on front down tube 906L is shown unoccupied and having minimal structure protruding beyond the extents of front down tube 906L.
