Motor vehicles – With means for promoting safety of vehicle – its occupant or...
Reexamination Certificate
1999-03-11
2001-02-20
Johnson, Brian L. (Department: 3618)
Motor vehicles
With means for promoting safety of vehicle, its occupant or...
C180S275000, C303S006100
Reexamination Certificate
active
06189644
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an emergency brake lock assembly for use with vehicles. More specifically, the present invention relates to an emergency brake lock assembly for use in vehicles that have an auxiliary door and lift assembly. The emergency brake lock assembly prevents the vehicle from moving while the lift assembly is being operated.
Buses that are used to transport handicapped passengers confined to wheelchairs typically include an auxiliary door formed in either the side of the bus or at the rear of the bus. When the auxiliary door is open, a lift assembly having a vertically movable platform is used to load and unload the wheelchair passengers from the bus through the auxiliary door. During loading and unloading, it is critical that the bus remain stationary to prevent injury to the wheelchair passengers and pedestrians.
In order to prevent the bus from moving while a wheelchair passenger is being loaded and/or unloaded, brake interlock systems have been developed that tap into the hydraulic brake lines of the bus to lock the bus brakes while the lift assembly is being operated. While this type of system functions well to prevent inadvertent movement of the bus while the lift assembly is being operated, the system suffers from several significant drawbacks.
For example, if the brake interlock device identified above is retrofit into a previously manufactured bus, a mechanic must tap into the hydraulic brake fluid lines in the bus in order to install the brake interlock device. According to the brake warranty offered by many bus manufacturers, if the hydraulic brake fluid system is modified, the manufacturer's warranty for the braking system is rendered void. Thus, when retrofitting existing buses including wheelchair transports, the owner of the bus is hesitant to install a brake interlock device that tampers with the existing hydraulic braking system.
Additionally, installing a brake interlock device that taps into the hydraulic braking system of the bus is difficult and time consuming. Typically, to install the interlock the mechanic must have access to the underside of the bus, which may require the mechanic to work on his back beneath the bus. When installing the brake interlock device, the mechanic must be sure not to introduce any leaks into the braking system that would drain the hydraulic fluid from the braking system, thus rendering the vehicle brake system ineffective.
Therefore, it is an object of the present invention to provide an emergency brake lock assembly that can be easily retrofit to existing vehicles without tampering with the existing hydraulic braking system. It is an additional object of the invention to provide an emergency brake lock assembly that prevents the vehicle from moving while the auxiliary door is open and the lift assembly is being operated. It is a further object of the invention to provide an emergency brake lock assembly that energizes the lift assembly only when the emergency brake is engaged and the emergency brake actuator is securely held in the engaged position. It is an additional object of the invention to provide an emergency brake lock assembly that includes a locking member that engages the emergency brake actuator contained in the bus and locks the emergency brake actuator in the engaged position. It is an additional object of the invention to sense the opening of the auxiliary door and engagement of the emergency brake to both retain the emergency brake actuator in the engaged position and energize the lift assembly.
SUMMARY OF THE INVENTION
The present invention is an emergency brake lock assembly that prevents a vehicle from moving while a lift assembly positioned in an auxiliary door of the vehicle is being operated. The emergency brake lock assembly includes a locking member positioned on a mounting plate that is secured within the interior of the vehicle near the emergency brake actuator that operates the vehicle's emergency brakes. The emergency brake actuator is movable between an engaged position in which the emergency brake prevents the vehicle from moving, and a disengaged position in which the emergency brakes are released and the vehicle is free to move. When the emergency brake actuator is moved into its engaged position, the emergency brake actuator contacts an emergency brake switch mounted to the mounting plate. Upon being actuated, the emergency brake switch generates a brake engaged signal and connects the ground circuit to the auxiliary door switch.
In addition to the emergency brake switch, the emergency brake lock assembly uses an auxiliary door switch that is positioned to detect the opening and closing of the auxiliary door. Specifically, the auxiliary door switch is positioned such that the auxiliary door contacts the auxiliary door switch when the auxiliary door is closed. When the auxiliary door is open, the auxiliary door switch generates a door open signal and completes the ground circuit to the emergency brake lock assembly.
During use of the emergency brake lock assembly, when the emergency brake actuator is engaged and the auxiliary door is open, a solenoid actuator moves a locking member to its locked position. When the locking member is in the locked position, the locking member engages and retains the emergency brake actuator in the locking claw of the locking member. As long as the door open signal and brake engaged signal are being generated, the locking member remains in the locked position to retain the emergency brake actuator in the engaged position. Thus, when the auxiliary door is open and the emergency brake is engaged, the emergency brake lock assembly provides a mechanical interlock that locks the emergency brake actuator in the engaged position to prevent the vehicle from moving.
While the door open signal and brake engaged signal are being generated, the emergency brake lock assembly energizes the lift assembly such that the lift assembly can be used to lift wheelchair passengers into and out of the auxiliary door of the vehicle. Unless both the door open signal and the brake engaged signal are being generated, the lift assembly will not be energized. Thus, the lift assembly can be used only when the auxiliary door is open and the emergency brake is engaged, thereby preventing the vehicle from moving.
Once the wheelchair passengers have been loaded or unloaded, the lift assembly is moved to its stored position and the auxiliary door is closed. As the auxiliary door closes, it contacts the auxiliary door switch causing the auxiliary door switch to cease generating the door open signal. After the door open signal has been terminated, the solenoid actuator moves the locking member to the unlocked position thereby allowing the emergency brake actuator to be moved from the engaged position. Once the emergency brake actuator has been moved to the disengaged position, the vehicle can be operated in a normal manner.
Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings.
REFERENCES:
patent: 2152084 (1939-03-01), Paine
patent: 2318610 (1943-05-01), Hyatt et al.
patent: 2866511 (1958-12-01), Niederoest
patent: 3893697 (1975-07-01), Blitz et al.
patent: 3929033 (1975-12-01), Marx
patent: 4074787 (1978-02-01), Cunningham et al.
patent: 4909096 (1990-03-01), Kobayashi
patent: 5505528 (1996-04-01), Hamann et al.
patent: 5839304 (1998-11-01), Wills
Andrus Sceales, Starke & Sawall
Fleming Faye M.
Johnson Brian L.
Nelson's Bus Service, Inc.
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