Brakes – Vehicle
Reexamination Certificate
2002-05-17
2003-12-02
Hurley, Kevin (Department: 3611)
Brakes
Vehicle
C280S250100
Reexamination Certificate
active
06655503
ABSTRACT:
FIELD OF INVENTION
The present invention relates to a cam type rearward motion brake for wheelchairs to enable the cognitively impaired to disembark safely from a wheelchair.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 4,987,978 (1991) to Jungersen discloses a safety brake for active cognitive wheelchair users. It allows settings for forward only or backward only braking motion. The system is designed for ramp travel. An egg shaped cam has two cam segments engagable with the tire. A spring-loaded cam follower urges the cam against the tire. A manual lever on the cam can be set to a neutral position which will only provide manual braking via the brake lever. Alternatively the cam lever can be set to an automatic forward brake or an automatic rearward brake position where the brake lever is in the “brake” position, but only a forward or a backward rotation of the tire will cause the cam segment to brake the wheel. This allows a cognitive user using his arms to go up a ramp and rest without rolling backwards. The present invention does not require a cognitive action by the user. The system is not designed for ramp travel, but instead for disembarkation by a non-cognitive user. The present invention does not provide for traditional braking at any time by using the brake lever because the user can only shuffle about with his own feet without using his arms for propulsion. When the brake lever is left alone the tire can move forward, but a cam prevents backward motion. This system makes disembarking from the wheelchair a no brainer function since nobody has to set any brake lever. The tires cannot rotate backward unless pressure is exerted on the brake lever. Another feature of the present invention is a tire lock mode which can be manually set to prevent any motion at all. The present invention is generally referred to as an automatic anti-rollback assembly.
Other anti-rollback assemblies include U.S. Pat. No. 5,984,334 (1999) to Dugas. The seat is spring-loaded as the user lifts his weight off the seat, a spring raises the seat, thereby pulling upward on an axle assembly which locks the brakes against the tires.
U.S. Pat. Nos. 6,092,824, 6,279,936B1 and U.S. publication US2001/0040354A1 to Ritchie et al. discloses a seat activated one-way brake assembly which uses a crossbar member to lock against the tires when the user's weight is not present on the seat.
SUMMARY OF THE INVENTION
The main aspect of the present invention is to provide a hands free non-weight activated cam assembly for a rearward brake for a wheelchair or other invalid transporter having wheels.
Another aspect of the present invention is to provide a universal mounting bracket(s) for most wheelchair frames.
Another aspect of the present invention is to provide a spring-loaded brake lever which automatically engages the tire without any cognitive action by a user.
Another aspect of the present invention is to provide a locking arm which can be manually set to lock the tire.
Another aspect of the present invention is a safety brake assembly for a wheelchair which prevents rearward movement of the wheelchair unless the brake handles of the brake assemblies are held back by the occupant. Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
Upon release of the brake handles the wheelchair is prevented from rearward movement. The device comprises a frame attached to the wheelchair, a pivoting brake lever attached to the frame which includes a round wheel with an off-center axle which is placed in front of the wheelchair tire, a limit pin mounted on the inside of the round wheel which comes in contact with the pivoting brake lever preventing the round wheel from rotating backward beyond a set point and preventing the round wheel from rotating forwards beyond a set point, a pivoting brake handle mounted on the frame and attached to a second pivoting member with an internal flange which prevents the brake handle from moving forward beyond a set point. The second pivoting member is also attached to the brake lever between the frame pivot and the round wheel in such a manner as to disengage the round wheel from the wheelchair tire when the brake handle is pulled backwards. A spring is attached between the brake lever and brake handle which causes the brake lever to move back and the brake handle to move forward until the brake handle reaches the internal flange on the second pivoting member and the round wheel comes in contact with the wheelchair tire. When a rearward force is applied to the wheelchair with the brake handles in the forward position against the internal flange of the second pivot member, the round wheel which is in contact with the wheelchair tire rotates backwards until the limit pin comes in contact with the pivoting brake lever. Since the round wheel has an off center axle, as the round wheel rotates backwards pressure is increased against the wheelchair tire until it stops rotating rearward which causes the wheelchair to stop rolling rearward.
The device replaces the existing brake mechanisms (left side and right side) on a wheelchair. The device may include a locking lever attached to the brake lever which can be placed over the limit pin which holds the round wheel in its rearward position, thus applying the greatest pressure on the wheelchair tire and preventing the wheelchair from moving forward and rearward.
REFERENCES:
patent: 3556260 (1971-01-01), Meyer et al.
patent: 4462605 (1984-07-01), Morgan et al.
patent: 4560033 (1985-12-01), DeWoody et al.
patent: 4987978 (1991-01-01), Jungersen
patent: 5029674 (1991-07-01), Boyes et al.
patent: 5492355 (1996-02-01), Berry
patent: 5667236 (1997-09-01), Murphy
patent: 5984334 (1999-11-01), Dugas
patent: 6007082 (1999-12-01), Watwood et al.
patent: 6092824 (2000-07-01), Ritchie et al.
patent: 6102166 (2000-08-01), Blodee
patent: 6253880 (2001-07-01), Faber
patent: 6279936 (2001-08-01), Ritchie et al.
patent: 6308804 (2001-10-01), Roberts
patent: 6464044 (2002-10-01), Suganuma
patent: 2001/0040354 (2001-11-01), Ritchie et al.
Hurley Kevin
Lum L.
Martin Rick
Patent Law Offices of Rick Martin PC
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