Material or article handling – Self-loading or unloading vehicles – Loading or unloading by other carrier or mover means – and...
Reexamination Certificate
1997-10-27
2001-03-20
Werner, Frank E. (Department: 3652)
Material or article handling
Self-loading or unloading vehicles
Loading or unloading by other carrier or mover means, and...
C414S921000, C414S540000, C414S917000, C188S036000
Reexamination Certificate
active
06203266
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to the field of vehicular wheelchair lifts for persons who are physically challenged or otherwise have limited mobility. More particularly, the present invention relates to the field of vehicular wheelchair lifts with an automatic safety barrier for preventing a wheelchair from inadvertently rolling off a platform of the wheelchair lift in the boarding and exiting of a vehicle.
2. Description of the Prior Art
Vehicular wheelchair lifts are widely utilized to assist persons in wheelchairs to enter and exit vehicles. These lifts typically have a platform for transporting an occupied wheelchair, where the platform can be raised and lowered between a loading position at the ground level outside a vehicle and an entry position at the floor level inside the vehicle, and a safety barrier connected to an outer end of the platform for preventing a wheelchair from inadvertently rolling off the platform during use of the wheelchair lift.
While many of the prior art safety barriers have accomplished in minimizing the risk for injury to users of the wheelchair lifts on which they are installed, a need has developed for even greater security in this respect. Many prior art barriers currently in use are subject to the possibility that they may not always be operative by both power and manual controls. Some prior art safety barriers are not strong enough to positively assure against accident and resultant injury. These safety barriers stop to prevent objects from sliding or rolling off the lifts and are well known as disclosed in the following prior art patents below.
U.S. Pat. No. 5,556,250 issued to Fretwell et al. on Sep. 17, 1996 discloses a wheelchair lift with a power roll stop actuated by a separate motor drive mechanism. If power or the motor becomes inoperable by any reason, disassembly some linkage parts in the motor drive mechanism is a must in order to, manually open and close the roll stop.
U.S. Pat. No. 4,124,130 issued to Rohrs et al. on Nov. 7, 1978 discloses a wheelchair lift with a safety barrier. The safety barrier is not power controlled.
U.S. Pat. No. 5,040,936 issued to Rhea on Aug. 20, 1991 discloses a wheelchair lift with a foldable safety barrier. The safety barrier is not power controlled.
U.S. Pat. No. 4,556,128 issued to Thorley et al. on Dec. 3, 1985 discloses a wheelchair lift with a power safety barrier. The safety barrier is actuated by a hydraulic cylinder. If the hydraulic power or any element becomes inoperable, the safety barrier cannot be opened and closed manually.
U.S. Pat. No. 5,439,342 issued to Hall et al. on Aug. 8, 1995 discloses a platform wheelchair lift with a safety barrier actuation mechanism. The actuation mechanism is driven by a hydraulic cyliner. The barrier cannot be opened and closed manually in the event of a power failure.
U.S. Pat. No. 4,442,921 issued to Sherman on Apr. 17, 1984 discloses a wheelchair platform lift with a safety barrier. The barrier is actuated by a barrier pivotal latch mechanism without power control.
U.S. Pat. No. 5,401,135 issued to Stoen et al. on Mar. 28, 1995 discloses a wheelchair lift with a safety barrier. The barrier opens and closes by a barrier pivotal latch mechanism without power control.
It is desirable to provide a wheelchair lift with a power controlled safety barrier for facilitating the entrance and exit of persons who are physically challenged or otherwise have limited mobility into or from a vehicle which significantly improves the safety of the wheelchair lift. It is also desirable to provide a wheelchair lift with a power controlled safety barrier which eliminates risks attributable to a wheelchair inadvertently rolling off a platform of the wheelchair lift during use.
SUMMARY OF THE INVENTION
The present invention is a vehicular wheelchair lift with a power controlled safety barrier for physically blocking a wheelchair from inadvertently rolling off a platform of the wheelchair lift during use. The power safety barrier utilizes a linkage mechanism for lowering or raising a roll stop. The linkage mechanism includes a pair of linkage bars and a flexible linkage member to mechanically connect the roll stop to a power actuating means, such as a motor drive assembly.
Specifically, the roll stop is pivotably mounted at an outer end of the platform of the vehicular wheelchair lift. The roll stop is required to open and close relative to the platform according to the relative platform positions. The wheelchair lift usually has three interval lift positions which includes a stowed position, an entry position in which the platform has reached a vehicle floor level, and a ground position. In the entry position and between the entry and ground positions, the roll stop is in a closed position substantially vertical to the platform for loading a wheelchair. When the platform is in the ground position, the roll stop is opened substantially in a horizontal plane and relatively coplanar to the platform and is an extension of the platform for unloading the wheelchair.
In the powered control aspects, during the wheelchair lift transition period when the platform is off the ground position, the roll stop is actuated to the closed position before the wheelchair lift can be operated. Reversely, during the wheelchair lift transition period when the platform is lowered to the ground, the roll stop cannot be actuated to the open position until the platform has reached the ground position.
The unique feature of the present invention is that, unlike the prior art safety barriers, the present invention safety barrier can be operated in either an automatic powered control mode or manual control mode under the same simple structure. No additional parts are required to be added to the structure to perform both modes. In addition, there is no need to further assemble or disassemble the linkage mechanism in the structure from one control mode (such as power control) to the other (such as manual control).
It is an object of the present invention to provide a vehicular wheelchair lift with a power controlled safety barrier which automatically opens and closes a roll stop relative to a platform of the wheelchair lift according to the relative platform positions.
It is also an object of the present invention to provide a vehicular wheelchair lift with a power controlled safety barrier which can be operated in either an automatic powered control mode or manual control mode under the same simple structure.
It is a further object of the present invention to provide a vehicular wheelchair lift with a power controlled safety barrier which includes a linkage mechanism having a pair of linkage bars and a flexible linkage member to mechanically connect the roll stop to a power actuating means for opening or closing the roll stop.
Further novel features and other objects of the present invention will become apparent from the following detailed description, discussion and the appended claims, taken in conjunction with the drawings.
REFERENCES:
patent: 4124130 (1978-11-01), Rohrs et al.
patent: 4442921 (1984-04-01), Sherman
patent: 4556128 (1985-12-01), Thorley et al.
patent: 4907936 (1990-03-01), Bourdage
patent: 4984955 (1991-01-01), McCullough
patent: 5040936 (1991-08-01), Rhea
patent: 5105915 (1992-04-01), Gary
patent: 5180275 (1993-01-01), Czech et al
patent: 5401135 (1995-03-01), Stoen et al.
patent: 5439342 (1995-08-01), Hall et al.
patent: 5556250 (1996-09-01), Fretwell et al.
DeLeo Dante Vincent
Savaria Pierre
Chen Tony D.
Fong Jerry
Ricon Corporation
Rozsa Thomas I.
Werner Frank E.
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