Patent Application
20050236813
The present invention relates generally to personal mobility aids, and in particular, to a personal mobility aid with adjustable structural members that are easily adjusted through the use of a washer.
Mobility aids such as wheelchairs and walkers are used by a significant portion of society. These mobility aids provide an important function for those they assist. In order to effectively serve this function, however, a mobility aid must be appropriately sized for the individual it is assisting.
Manufacturers of mobility aids address this requirement by making their mobility aids adjustable. A common approach is to provide multiple locations on a given structural member of the mobility aid where another member may attach. In this manner, a user can change the structural dimensions of the mobility aid by adjusting the attachment locations of various structural members.
As an example, two or more structural members of a device may be attached by fasteners (such as bolts) which fit within corresponding fastener openings on the structural members. Additional fastener openings on one or both of the structural members provide alternative coupling locations between the structural members. Changing fastener openings modifies the position of the members relative to one another, thus changing the dimensions of the device.
A drawback of this simple approach is the cumbersome nature of the process. To change fastener openings on the structural members, the user must disassemble and remove the fasteners, usually a nut-bolt-washer combination. Often, multiple fasteners must be removed to facilitate the change. Once this is accomplished, the user must align the desired fastener openings on the corresponding members, hold the various parts and the structural members in place, and insert and reassemble the fasteners. A common result is for a washer to slip out of alignment or fall out of the assembly during the process.
In one aspect, the present invention relates to a personal mobility aid and/or to a washer for use therein. The mobility aid includes first and second structural members and a fastener for connecting the first and second members together. Further, the mobility aid includes a washer which has first and second portions connected by a bridge portion. The first and second portions each have a fastener opening for receiving the fastener.
In another aspect of the invention, a method of connecting first and second connecting plates to a frame member of a personal mobility aid includes the steps of placing a washer on the frame member so that the washer has first and second portions spaced apart on opposite sides of the frame member; placing the first and second connecting plates adjacent the first and second portions of the washer; and fastening the connecting plates and the frame member and the washer together with a fastener.
FIGS. 6 to 9 are two perspective views, a front view, and a side view, respectively, of a first embodiment of a washer of the present invention.
In the accompanying drawings, which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which, together with the detailed description given below, serve to exemplify the principles of this invention. The invention is not limited by the fact that certain embodiments are illustrated, but rather is broader in scope, as shown in the appended claims.
The first and second rear wheels 12 and 12a engage the ground surface for rolling and are adjustably coupled to the rear section of the first and second side frame 20 and 20a, respectively. The first and second front casters 14 and 14a also engage the ground surface for rolling and are supported on the front section of first and second side frames 20 and 20a, respectively. The first and second side frames 20 and 20a are, themselves, adjustably coupled to the first and second seat rails 22 and 22a, respectively. Additionally, the first and second back tubes 24 and 24a are also adjustably coupled to the first and second seat rails 22 and 22a, respectively.
In the mobility aid 10 shown in
In the preferred embodiment of the invention, the bridge portion 40, the first portion 32, and the second portion 36 are formed as one piece. In other embodiments, the washer portions 32, 36 and 40 might be formed separately and joined to each other to form the completed washer 30. The bridge portion 40 of the washer 30 connects the first portion 32 to the second portion 36 in an orientation such that the first portion and the second portion are spaced apart from and extend generally parallel to each other. In this arrangement, the washer 30 has the generally U-shaped configuration and the first and second fastener openings 34 and 38 are co-axial.
In accordance with the invention, the first portion 32 of the washer 30 and the second portion 36 of the washer can be positioned on opposite sides of a structural member of a mobility aid, thereby to locate and support the washer on the structural member.
As shown in
The inner surfaces 42, 46 and 50 of the washer 30 form a continuous inner surface that abuttingly engages an outer surface 60 of the structural member 22 once the washer is in place on the structural member. Further, the first portion 32 and the second portion 36 of the washer 30 have portions that are spaced apart a distance less than the width of the structural member 22 when the washer is in a free state. In the most preferred embodiment, the portions that are spaced apart a distance less than the width of the structural member are the first lip 62 and the second lip 64 at the washer open end 54. This dimensioning of the washer 30 enables the snapping-on motion described above, and also enables the self-retention of the washer on the structural member 22.
Because the washer 30 is self-supporting on the structural member 22, assembly and disassembly and adjustment of the coupled parts of the mobility aid 10 are substantially easier. The washer 30 (or two separate washers) need not be held in position while a fastener, such as a bolt, is used to fasten the parts together. The characteristics of the washer 30 that are desirable include inexpensive manufacture cost, resiliency, durability, and light weight. Nylon plastic (DSM 1821-A or equivalent) is the preferred material to meet these characteristics, although other materials are certainly suitable.
The specific wheelchair 10 that is shown in
Because the several adjustable couplings in the wheelchair 10 are similar to each other in construction and operation, the connection between the first seat rail 22 and the first side frame 20 will be described as exemplary. The first seat rail 22 is positioned above and generally parallel to the first side frame 20. The first seat rail 22 has a plurality of fastener openings 80 spaced apart along the length of the seat rail. Each fastener opening 80 on the first seat rail 22 serves as an alternative location at which the first side frame 20 can attach, to adjustably couple the two structural members to each other.
The washer 30 is positioned on the first seat rail 22 at a location so that the first fastener opening 34 and the second fastener opening 38 in the washer align with a selected fastener opening 80 in the first seat rail. In a similar manner, two additional washers 30 are positioned at spaced locations on the first side frame 20 such that their fastener openings are aligned with fastener openings on the first side frame.
The first frame plate 72 and the second frame plate 72a are positioned to abuttingly engage the outer surface 44 of the first portion 32 of the washer 30 and the outer surface 48 of the second portion 36 of the washer, respectively. Fastener openings 82 on the first frame plate 72 and the second frame plate 72a are aligned with the first fastener opening 34 and the second fastener opening 38 of the washer 30. A fastener 74 is inserted through the aligned fastener openings. The fastener 74 extends through the fastener opening 82 in the first frame plate 72; the fastener opening 34 in the first portion 32 of the washer 30; the pair of fastener openings 80 on opposite sides of the seat rail 22; the fastener opening 38 in the second portion 36 of the washer; and the fastener opening 82 in the second frame plate 72a. The fastener 74 is secured in position by a nut 84. All this is done while the washer 30 is supporting itself on the seat rail 22.
While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, the washer can be made from a variety of materials; the mobility aids utilizing the washers can vary in type (e.g. wheelchairs, crutches, walkers, rollators) and configuration (e.g. motorized, manual, sport); the washer can be designed to fit structural elements in a variety of sizes and shapes (e.g. round, oval, rectangular, square). Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant's general inventive concept.
