NONOBVIOUSNESS Carter

Chosen Invention

Patent 4252138: Adjustable Crutch for Raising From Seated to Standing Position

Date Issued: February 24, 1981

The foundation of the invention is a crutch with a length that can be manually adjusted through the use of a lever. The user reduces the height of both crutches to a minimum while in a seated position and then places his weight upon both crutches. In order to raise to a standing position, the user alternately shifts his weight from one crutch to the other, while operating the lever on the crutch that is not supporting any weight. By operating the lever of the non supportive crutch, the user can increase the length iteratively until both crutches are at the proper height for standing position.

Evaluation of Patent

Regarding Cases: Hotchkiss v. Greenwod, A&P Tea Co. v. Supermarket Corp., and Lyon vs. Bausch & Lomb

Overview of Referenced Patents:

Patent 3738674

The most recent reference cited by Patent 4252138, the height adjustable crutch, was Patent 3738674, the “ski equipped crutch,” which describes an invention predicated on the design of an instrument that can be utilized as both a ski/ski pole and a crutch. The patent for the “ski crutch” highlights the ability of the ski portion of the instrument to fold up and essentially form a regular shaped forearm crutch. Also included in the design outline is the presence of a slip-resistant member to prevent slippage in snowy conditions and a claw like appendage that can be employed as a brake when the “ski crutch” is used for downhill skiing. Like the height-adjustable crutch, the “ski crutch” is aimed at not only facilitating the typical motion of a handicapped individual, but also assisting the individual in situations where a typical crutch cannot provide such help. The focus of this design on the ability to manipulate the crutch to fit two specific purposes is the most crucial element. While Patent 4252138 has no ski attachment or brake mechanism, it utilizes the same concept of adjusting the shape and size of the crutch for two specific scenarios: standing and sitting.

Patent 2960095

Another patent referenced is Patent 2960095, which describes a walking cane that can easily be converted into a crutch. Using sliding and revolute joints, the handle of the walking stick can be converted into the arm rest for the crutch and the height of the support device can be adjusted to meet the needs of the user. The major connection between this patent and the height adjustable crutch is the ability of the crutch to be easily adjusted, specifically the overall height of the instrument. The way in which the crutch is adjusted though is different for each design, as the walking cane/crutch has to be adjusted near the center of the cane by the user, an action that cannot be done easily while maintaining one’s balance. The more recent design allows for adjustment of the crutch height through the manual operation of a lever, which allows for the handicapped individual to rise from a seated to standing position. Both designs however maintain the same shape (only reduced or increased in length) during the adjustment process.