Motor vehicles – Special driving device – Stepper
Reexamination Certificate
2000-07-03
2002-11-26
Hurley, Kevin (Department: 3611)
Motor vehicles
Special driving device
Stepper
C180S008300
Reexamination Certificate
active
06484829
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATION
One object of this application to define an improvement over my previously patented stair-climbing wheelchair (U.S. Pat. No. 4,512,588) entitled “Stair Climbing Wheel Chair”. This new design offers a narrower width and requires less driver strength and skill.
BACKGROUND—TECHNICAL FIELD OF INVENTION
This invention relates generally to stair-climbing wheelchairs that are propelled by battery-powered electric motors and are driver-controlled.
BACKGROUND—DISCUSSION OF PRIOR ART
The mobility of persons who do not enjoy the full use of their legs and feet has been restricted by the absence of an economical and dependable way of negotiating obstacles such as curbs, steps, stairs, and narrow doorways, etc. Persons who cannot walk have therefore been denied the same kind of freedom that others routinely take for granted. The absence of mobility and freedom of travel for those who cannot walk has not gone unnoticed. Many talented persons have devoted their creative genius to the fabrication of vehicles that purport to provide this desired mobility. The various solutions that have been offered from time to time may be broadly divided into three main categories as follows: 1) endless track or belt; 2) spider wheel, including 2-, 3-, 4-, 5-, and even 6-wheel configurations; and 3) other devices, including those which teach the use of articulated struts, etc.
The endless track/belt category uses tracks or belts like those employed on a bulldozer or a military tank. Examples include U.S. Pat. No. 4,154,315 to Rasmussen entitled “Chassis For Stair-Climbing Vehicles”; U.S. Pat. No. 4,044,850 to Winsor entitled “Wheelchair”; and U.S. Pat. No. 4,061,199 to Last entitled “Chassis For A Vehicle Capable of Travelling Over Obstructions.”
The spider wheel category uses wheels that have multiple spokes with a small diameter wheel at the end of each spoke. The spokes visually suggest the legs of a spider. An example of a 2-wheel spider wheel is found in U.S. Pat. No. 5,701,965 to Kamen et al. entitled “Human Transporter”. Examples of 3-wheel spider wheel-type chairs include the following U.S. Pat. No. 3,241,848 to Flory entitled “Stair-Climbing Vehicle”; U.S. Pat. No. 2,931,449 to C. A. King entitled “Occupant-Controlled, Self-Propelled, Obstruction-Climbing Vehicle”; and U.S. Pat. No. 2,742,973 to H. A. I. Johannesen entitled “Powered Invalid Chair and Handle Control Therefor.” Examples of 4-wheel spider wheel-type chairs include: U.S. Pat. No. 4,512,588 to Cox entitled “Stair Climbing Wheel Chair” and U.S. Pat. No. 3,580,344 to Floyd entitled “Stair-Negotiating Wheel Chair or an Irregular-Terrain-Negotiating Vehicle”. An example of a 5-wheeled device (as well as 3,4,6 or more wheels) is shown in U.S. Pat. No. 255,693 to J. C. Tauber entitled “Stair Truck.” A 6-wheeled construction is shown in U.S. Pat. No. 3,208,544 to Colvin entitled “Stepping Wheel Vehicle.”
Examples of constructions that employ cylinders and movable pistons include U.S. Pat. No. 3,269,478 to Joslyn entitled “Stair Climbing Wheel Chair”; U.S. Pat. No. 3,550,709 to Hottel entitled “Self-Powered Climbing Hand Truck”; and U.S. Pat. No. 3,417,831 to Lake entitled “Hand Truck with Power Lift.”
Regrettably, most of the above-described patents have focused attention only on the problem of getting up and down stairways. It must be recognized that wheelchairs face other barriers besides stairs. In order to take full advantage of the stair-climbing capability, the wheelchair must also accommodate those other barriers.
A major problem with many wheelchairs, whether of the stair-climbing variety or otherwise, is the width of the wheelchair. Many electrically-powered wheelchairs have been proposed in the past which are too bulky. They are large and are incapable of passing through narrow doorways. In the United States many doors leading to bathrooms are only 61-centimeters (24-inches) wide. Interior trim that usually sticks out more than a few centimeters makes the practical width of these doorways about 55.9-centimeters (22-inches). An ideal wheelchair should be less than 55.9-centimeters (22-inch) to provide a minimal amount of clearance during passage into and out of a bathroom. It should still provide a wheelchair seat that is as wide as possible—for the personal comfort of the driver. Most of these previous commendable efforts have provided mechanisms that are bulky and cumbersome. They cannot meet the spatial requirements of the real world. Some wheelchairs did provide access through narrow passageways and tight turning areas. However, they required upper body strength and reach for holding on to handrails for stair climbing. Some wheelchair designs failed to provide safe stability during stair climbing in the event of an unintentional loss of battery power or control system failure.
Another problem faced by some who desire improved mobility is pressure sores that develop from sitting too long in one place. Reclining the seat and seat back can relieve this problem. Such systems are available on some conventional wheelchairs and would be beneficial on stair-climbing wheelchairs as well. Steep slopes are another obstacle faced by wheelchairs.
SUMMARY
In accordance with the present invention a stair-climbing wheelchair comprises a seat and a frame with spoked wheels on either side. There is a small wheel at the end of each spoke. A pitch-attitude sensing device and computer-controlled pitch attitude-adjusting skids on front and rear corners of the frame maintain the wheelchair seat level during stair climbing. There is at least one battery (and probably two), two motors for propelling the wheelchair, one other motor for rotating the spoked wheels, and two conventional electric-powered screw type actuators for positioning the front skids and the rear skids with caster.
OBJECTS AND ADVANTAGES
Accordingly, besides the objects and advantages of the stair-climbing wheelchair described in my above patent, several objects and advantages of the present invention are:
(a) to provide a wheelchair that can accommodate stairs, steps, slopes, narrow doorways, and tight turning spaces normally seen in homes, businesses, or places visited by the public;
(b) to provide a stair-climbing wheelchair that will enter narrow doorways and still provide wide and comfortable seating;
(c) to provide a stair-climbing wheelchair that can accommodate users while requiring very minimal driver skill and strength;
(d) to provide a stair-climbing wheelchair that also functions as a normal powered wheelchair without compromise to that function;
(e) to provide a stair-climbing wheelchair with the fewest possible restrictions, such as accommodating: variable step riser and tread geometries, narrow stair width, small stair landing size, lack of hand rails, low tread friction, and tread roughness;
(f) to provide a stair-climbing wheelchair that is passively secure on the stairs even with unintended loss of power, control system failure, or loss of control system stability;
(g) to provide the driver with a smooth comfortable ride on stairs with a feeling of confidence and without fear of unsafe operations;
(h) to provide an electrically-powered wheelchair that can climb steep slopes; and
(i) to provide an electrically-powered wheelchair that can recline the seat and seat back.
Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
REFERENCES:
patent: 2931449 (1960-04-01), King
patent: 4512588 (1985-04-01), Cox
patent: 4674584 (1987-06-01), Watkins
patent: 4794999 (1989-01-01), Hester
patent: 5423563 (1995-06-01), Wild
patent: 5579857 (1996-12-01), Abe et al.
patent: 5701965 (1997-12-01), Kaman et al.
patent: 5975225 (1999-11-01), Kamen et al.
patent: 6311794 (2001-11-01), Morrell et al.
LandOfFree
Battery powered stair-climbing wheelchair does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Battery powered stair-climbing wheelchair, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Battery powered stair-climbing wheelchair will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2927882