Modular multi-wall tray retrofitable to a wheelchair

Abstract

A robust multi-wall tray which is easily retrofitable to a wheelchair. Due to the structural design, the tray is lightweight but yet more rigid than conventional solid wheelchair trays. The multi-wall tray can be secured to a wheelchair with conventional means or with several novel means that provide a smooth work surface free of screws or Velcro™. A novel prior art adjustable tray support structure can also be integrated into the multi-wall tray to allow the system to mount robustly to the frame of a wheelchair and also allow the tray to fold away to the side of the wheelchair when not in use. Additionally, the multi-wall tray can have a sealed perimeter to create an enclosure for protecting electronic devices. The design can support electronic devices for computer assisted living while also providing a tray work surface for reading, writing or eating.

Description

RELATED APPLICATION Priority Claim [0001] This application is a continuation-in-part of U.S. patent application Ser. No. 11 / 200,838, filed Aug. 10, 2005, which claims the benefit of U.S. provisional application Ser. No. 60 / 600,853, filed Aug. 12, 2004, both of which are hereby incorporated herein by reference in their entirety. This application also claims the benefit of U.S. provisional application Ser. No. 60 / 680,153, filed May 12, 2005, which is also hereby incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The invention relates generally to multi-wall trays. More specifically, the invention relates to a plastic wheelchair tray which is engineered to be lightweight, yet very strong, and can house various mechanical and electronic components. [0004] 2. Description of Prior Art [0005] It can be appreciated that wheelchair trays have been in use for years. Wheelchair trays serve a multifunction role as an eating surfa...

AI Technical Summary

Benefits of technology

[0012] The present invention relates generally to a wheelchair tray and, more specifically, it relates to a modular multi-wall tray retrofitable to a wheelchair with provisions for housing various mechanical or electronic devices. The present invention generally comprises an engineered plastic tray, flexible trim molding along the outer perimeter of the tray and a mounting system means. The engineered sheet of plastic material utilized for the tray contains a hollow interior with a top and bottom panels joined by ribs and may be manufactured using traditional extrusion or injection molding techniques. One particular extruded plastic material is commonly referred to as a “multi-wall” panel. These multi-wall plastic panels are typically manufactured from polycarbonate or acrylic. Selection of the multi-wall material is novel for a wheelchair tray application due to the material's transparency, structural rigidity and low weight.

[0013] Wheelchair trays made from existing prior art materials such as solid plastic may require a separate support means such as an aluminum rim secured to the perimeter of the tray or a separate metal bracket extended from the front of the wheelchair. Therafin Corporation's “Extenda-Arm” tray support is an example of prior art used to keep wheelchair trays from flexing downward during use with a heavy object. The primary benefit in the use of the multi-wall plastic material for a wheelchair tray is that this type of material does not require a separate element (made of aluminum or other rigid material) secured along its exterior to enhance the panel's rigidity. This multi-wall plastic material can support considerable weight without deflecting downward substantially when a load is applied to its top surface. This feature, combined with the fact that the wheelchair tray made of multi-wall plastic weighs less than one half the weight of a clear solid plastic tray with the same surface area, makes installation and removal of the tray from a wheelchair much easier for disabled individuals.

[0014] Sometimes a conventional solid wheelchair tray must be secured more robustly to a wheelchair's armrest than with the standard Velcro® means wrapped entirely around the tray and wheelchair armrest. In the alternate mounting scenario, a pair of plastic or metal mounting brackets, which are designed and shaped to mount over the wheelchair armrest are attached to the underside of the wheelchair tray with screws, nuts, bolts or other mounting hardware. This tray / mounting bracket assembly is subsequently attached to the wheelchair armrests. Usage of such wheelchair tray mounting hardware typically requires that holes be drilled completely through the wheelchair tray; this, unfortunately, means that the top surface of a conventional wheelchair tray no longer has a smooth flush surface for the wheelchair user due to the exposed heads of the mounting screws. If a multi-wall wheelchair tray were used in place of the conventional solid wheelchair tray, the top surface of the tray would be perfectly smooth for the user with no exposed screws or Velcro™ straps.

[0015] The internal openings in the tray provide a novel benefit: this open space can be utilized to house various mechanical, electronic and / or electro-mechanical devices. This feature not only keeps items within close-proximity to the user, but can also keep valuable electronics from being dropped or protecting the valuable electronics from solid or liquid contaminants. The inventions disclosed allow liquid or solid foods to be eaten, documents (either physical on the wheelchair tray or digital within a computer display) to be signed and read, or heavy objects to be placed onto its top surface of the tray without damaging the valuable electronic equipment housed inside. All of this can occur, while allowing the use of a fully-functional computer, cell phone, or other electronic accessories with enhanced communications and entertainment capabilities, as well as providing a comfortable and stable platform for the wheelchair user.

[0016] Electronic devices can be protected inside the tray by a light-weight, flexible, low-durometer trim molding secured along the entire perimeter of the tray with a conventional adhesive. This preferred assembly technique can provide a robust water-resistant seal along the entire perimeter of the tray to an IP21 level of water and dust ingress protection or greater per IEC 60529. The benefit of such a seal is that electronics secured inside the internal openings of the modular wheelchair tray can be protected from contact with water or dust.

[0017] A light-weight, flexible, low-durometer trim molding secured along the entire perimeter of the tray also provides safety benefits. Such trim molding can help to absorb the force of impact if, say, the wheelchair tray assembly is accidentally dropped. If dropped onto the ground, the edges and corners of the wheelchair tray are better protected from the impact; but, more importantly, if dropped onto a person's foot, less impact force will be imparted to the person. This trim molding, combined with the proposed light-weight wheelchair tray (which is 100%'s lighter in weight than a traditional standard solid wheelchair tray due to the use of the multi-wall plastic material) will provide a safer wheelchair tray operating environment for wheelchair users and healthcare workers.

Problems solved by technology

However, when the conventional solid wheelchair tray is secured to a wheelchair and an item such as a portable laptop computer is placed on top of this type of wheelchair tray, the tray flexes downward at the non-secured, cantilevered end.

However, utilizing the same but only thicker material for the wheelchair tray also means that the tray will increase in weight.

Any added weight due to the use of a thicker material will make it more difficult for the wheelchair user to hold onto the wheelchair tray during installation and removal to / from the wheelchair.

However, one problem with conventional wooden wheelchair trays is that they do not provide transparency and thus prevent the user from seeing his / her feet during use.

The wooden trays which are more rigid than plastic are heavy and can, therefore, present another problem to the wheelchair bound individual.

The weight of the wheelchair tray directly impacts the ability of the user or caregiver to remove and place the tray onto the wheelchair.

Conventional solid wheelchair trays have a limited amount of space available on the top surface of the tray for daily use.

This limited amount of “real estate” often causes objects to fall from the surface, necessitating the need for a raised rim to contain objects.

A rigid rim made of aluminum may pose a safety risk for individuals dining everyday use, due to the proximity of the arms on top of the tray.

Current designs can injure someone through bumping, sliding or scraping of the arms against this rim.

Due to poor circulation that may be present in many wheelchair users, skin breakdown and infection can occur from the slightest skin abrasion.

In addition, some wheelchair users may have tremor disorders or trashing of the body due to a disability such as epilepsy—the use of a solid protruding rim may pose a high risk of injury and in many cases can prevent the use of this type of wheelchair tray altogether.

However, these devices have unique mounting and liquid-protection requirements.

While wheelchair trays and other conventional tray designs may be suitable for the particular purpose for which they serve, they are not as suitable for computer assisted living.

Conventional wheelchair trays do not provide a robust means to support, secure, encase, and / or protect electronic devices.

A portable computer or other electronic device that is simply placed onto the surface of a conventional wheelchair tray can easily fall from this mounting surface, potentially damaging the computer or injuring the computer user.

Also, these electronics can be easily damaged by foreign elements such as liquids or foods which might accidentally spill onto the electronic device.

Existing hand-held electronic devices can be difficult for a wheelchair user to hold while propelling a manual wheelchair or controlling an electronic wheelchair with a control joystick.

However, these electronics can be damaged if water, soda or any foreign liquid get into the electronic devices' protective enclosure.

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