Patent Application
20120080246
Embodiments of the present invention generally relate to wheelchairs, and, more particularly, to legrest assemblies for wheelchairs.
Power wheelchairs are used by disabled individuals in order to move around in comfort and relative ease. Indeed, these wheelchairs have improved throughout the years to provide numerous features that provide additional comfort to individuals.
A power wheelchair typically includes a base having wheels. The base supports a seat assembly. The individual controls operation of the wheelchair through a control interface, such as a joystick, typically positioned on an armrest of the seat assembly. The control interface is in electrical communication with a processing system that is also connected to motors that drive the wheels, a steering mechanism, and the like. The processing system generally controls overall operation of all powered aspects of the wheelchair.
A wheelchair also includes legrests in which an individual positions his/her legs. Many legrests are adjustable such that they may be moved through various positions.
The legrest assembly 14 may be adjusted so that it may rotate upward about an area where it connects to the seat assembly 12. That is, a proximal end of the central column 16 is pivotally connected to the seat assembly 12.
In order to adjust the legrest assembly 14, an actuator 22 may be engaged to move the legrest assembly 14. As shown in
The position of the actuator 22 behind and on the legrest assembly 14 provides a bulky assembly. The actuator 22 adds weight to the legrest assembly 14. As such, when moving the legrest assembly 14, the actuator 22 uses energy sufficient to move both the legrest assembly 14 and the actuator 22 itself. The added weight and bulk, as well as the center of gravity, may cause adjustment of the legrest assembly to be uneven and halting.
As shown in
Additionally, conventional wheelchair assemblies such as shown in
Certain embodiments of the present invention provide a wheelchair that includes a seat assembly configured to support an individual, a curved legrest assembly pivotally connected to the seat assembly, and an adjustment assembly configured to adjust the curved legrest assembly through a range of motion. The adjustment assembly may include an actuator operatively connected to the curved legrest assembly through a piston slidably secured within a sleeve. The adjustment assembly is secured underneath the seat assembly.
The legrest assembly may include a curved central column secured to curved legrest beams. The curved central column may include a first or male beam slidably secured to a second or female beam.
The curved central column is adjustably secured to the curved legrest beams through an extension bracket that allows for each of the curved central column and the curved legrest beams to be independently adjusted with respect to one another.
The extension bracket may include a central channel and two lateral channels. The curved legrest beams may be adjustably secured within the lateral channels, and the central column may be adjustably secured within the central channel. Each of the central channel and the lateral channels may connect to at least one threaded bore configured to receive a set screw. The set screws may be selectively tightened and loosened to adjust the curved legrest beams with respect to one another and the central column. Further, the extension bracket may be adjusted with respect to the central column in a like manner.
The wheelchair may also include a bracing bracket having a curved track secured underneath the seat assembly. The central column may connect to the bracing bracket through a rolling bracket having rollers abutting the curved track. The rolling bracket may be spring-biased with respect to the central column.
Certain embodiments of the present invention provide a legrest assembly for a wheelchair. The legrest assembly includes a curved central column having an end configured to be pivotally connected to a seat assembly of the wheelchair, a first curved legrest beam secured to one side of the curved central column, and a second curved legrest beam secured to an opposite side of the curved central column. The curve of each legrest beam may be aligned and consistent with that of the central column.
The curved central column may include a male beam slidably secured to a female beam. The first and second curved legrest beams may be secured to the female beam.
The legrest assembly may also include an extension bracket adjustably secured to each of the curved central column and the first and second curved legrest beams. The extension bracket secures the first and second curved legrest beams to the curved central column. The extension bracket allows for each of the curved central column and the first and second curved legrest beams to be independently adjusted with respect to one another.
The extension bracket may include a central channel and first and second lateral channels. The first and second curved legrest beams may be adjustably secured within the first and second lateral channels, respectively. The central column is adjustably secured within the central channel. Each of the central channel and the first and second lateral channels connects to at least one threaded bore configured to receive a set screw.
Certain embodiments of the present invention provide a powered wheelchair that includes a support base having wheels, a seat assembly supported by the support base, a curved legrest assembly, and an adjustment assembly. The curved legrest assembly is pivotally connected to the seat assembly. The curved legrest assembly includes (i) a curved central column having an end configured to be pivotally connected to a seat assembly of the wheelchair, (ii) a first curved legrest beam secured to one side of the curved central column, (iii) a second curved legrest beam secured to an opposite side of the curved central column, and (iv) an extension bracket adjustably secured to each of the curved central column and the first and second curved legrest beams. The extension bracket secures the first and second curved legrests to the curved central column. The extension bracket allows for each of the curved central column and the first and second curved legrest beams to be independently adjusted with respect to one another.
The adjustment assembly may include an actuator operatively connected to the central column through a piston slidably secured within a sleeve. The adjustment assembly may be secured underneath the seat assembly.
Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof.
The central column 50 is secured to legrest beams 56 through an extension bracket 58. Distal ends of the legrest beams 56 are connected to footrests 60.
Unlike the conventional wheelchair, the central column 50 and the legrest beams 56 are curved. The central column 50 and the legrest beams 56 generally bow out from proximal ends (closest to the seat assembly 46) and arc back from the bowed out area toward distal ends (closest to the footrests). Thus, the centers of the central column 50 and the legrest beams 56 may bow out to a greater extent than the ends of the respective central column 50 and the legrest beams 56.
Because the legrest assembly 48 is curved, as described above, the legrest assembly 48 moves along an arc as it rotates about the seat assembly 46. It has been found that the curved nature of the legrest assembly 48 adjusts the position of the footrests 60 during movement, which relieves pressure on an individual's heels as the legrest assembly 48 pivots outwardly from the seat assembly 46.
As shown in
A clamp 74 configured for receiving a web belt (not shown) that operatively connects to a rolling bracket 86 allows the female beam 72 to slide outwardly from the male beam 70. Optionally, the central column 50 may be a single unitary beam.
In any event, the proximal end 52 of the central column 50 secures to an axle 76 that is rotatably secured by opposing brackets 78 underneath the seat assembly 46. Optionally, the central column 50 may be integrally formed with the axle 76. The link 62 secures to the pivot bracket 54, which is secured to the central column 50 and/or the axle 76. Thus, when the actuator 68 (not shown in
A stud 80 extends beneath the central column 50 proximate the union with the axle 76. The stud 80 includes a spring 82 secured around a pin 86 that connects the stud 80 to a rolling bracket 88. The rolling bracket 88 includes wheels or rollers 90 at an end that is distally located from the pin 86. The rollers 90 are positioned within a curved track 92 of a bracing bracket 94. In an alternative embodiment, the wheelchair 40 may not include the stud 80, the rolling bracket 88 and the bracing bracket 94.
As the legrest assembly 48 moves outwardly from the seat assembly 46, the piston 64 pivots the central column 50 about the axle 76. As such, the rolling bracket 88 moves through the curved track 92 toward the axle 76. The spring 82, which is operatively connected to the rolling bracket 88, responsively resists and keeps the rollers 90 within the curved track 92 at all positions along the curved track 92. Consequently, the rolling bracket 88 pivots with respect to the stud 80 about the pin 86. Accordingly, the rolling bracket 88 provides bracing support to the legrest assembly 48 as the legrest assembly 48 moves. When the legrest assembly 48 moves back to its original position, the spring 82 ensures that the rollers 90 remain in the curved track 92.
A web belt (not shown), which may be formed of plastic, an elastomeric material, flexible metal, or the like, may be secured to the rolling bracket 88. The web belt may pass around the axle of the rollers 90. The web belt may also connect to the clamp 74. For example, the web belt may pass through the two aligned slots 89 formed through the clamp 74.
As the rollers 90 move, the rollers 90 adjust the tension in the web belt, allowing the female beam 72 to extend from the male beam 70 as tension is released, or pulling the female beam 72 onto the male beam 70 as tension is increased. In this manner, the web belt may allow for variable length of the female beam 72 with respect to the male beam 70.
The threaded bores 96 are configured to receive and threadably retain set screws (not shown). The set screws are used to adjust the central column 50 and the legrest beams 56 within the central and lateral channels 91 and 93, respectively.
Referring to
The extension bracket 58 allows for individual adjustment of legrest beams 56 with respect to the central column 50. Additionally, the extension bracket 58 may be adjusted with respect to the central column 50. That is, the set screws that engage the central column 50 may be loosened so that the extension bracket 58 may be slid up or down the central column 50 to a desired position, at which point the set screws may be tightened to secure the extension bracket 58 in place. Similarly, each legrest beam 56 may be individually adjusted with respect to the extension bracket 58.
Thus, the extension bracket 58 allows for separate and independent adjustment of the legrest beams 56 and the central column 50. Moreover, the extension bracket 58 provides a simple and light system for adjustment that does not significantly add weight and bulk to the legrest assembly 48.
Thus, embodiments of the present invention provide a legrest assembly for a wheelchair. Unlike the conventional wheelchair shown in
Further, the curved nature of the legrest assembly provides for increased comfort, as compared to the straight legrests of conventional wheelchairs.
Additionally, the simple, efficient, and light extension bracket allows for length adjustment of the legrest assembly. The extension bracket provides a lighter and less bulky legrest assembly as compared to the conventional wheelchair shown and described with respect to
Overall, it has been found that embodiments of the present invention provide a legrest assembly for a powered wheelchair that slides more smoothly and over a greater range than conventional wheelchairs, due to the curved nature of the legrest assembly and the actuator underneath the seat assembly. Additionally, embodiments of the present invention provide a lighter legrest assembly as compared to conventional wheelchairs. Moreover, it has been found that embodiments of the present invention provide a stronger and more stable legrest assembly. As noted above, embodiments of the present invention also provide a legrest assembly that reduces pressure on an individual's feet, as compared to prior wheelchairs.
Also, embodiments of the present invention provide a fully-adjustable legrest assembly that is simpler than previous legrest assemblies. That is, embodiments of the present invention provide a legrest assembly with less parts and simpler operation as compared to prior wheelchairs.
While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front and the like, may used to describe embodiments of the present invention, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like.
Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.
Various features of the invention are set forth in the following claims.
