Parking brake control system

Fluid-pressure and analogous brake systems – Speed-controlled – For a tractor-trailer type vehicle

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C303S007000, C303S020000, C303S089000

Reexamination Certificate

active

06685281

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention generally relates to braking systems for vehicles, such as buses, semi-tractor and trailers, and passenger vehicles. More particularly, this invention relates to a control system for automatically applying and maintaining a vehicle brake in the applied condition during times when it is unsafe or undesirable for the vehicle to move. The invention relates to a control system that may also lock the brake when an unsafe condition begins after the parking brake has been applied by the driver. Further, the invention relates to providing an electric/electronic switch for operation by the driver, replacing conventional manual hand and foot handles that must be pushed or pulled to set or release the parking brake. The invention also relates, in its preferred embodiments, to providing a system that responds to various signals on or away from the vehicle to control a parking brake on a remote piece of equipment, such as on a trailer, camper, or other towed vehicle.
The invention may be adapted for use with brakes of various types, for example, air parking brakes or mechanical parking brakes, or by adapting a hydraulic “application” brake, an air “application” brake, or an electric brake to serve as a parking brake. While the invention is primarily focused on parking brake improvement, the invention may be used, in some embodiments, to apply and control application brakes.
The automatic application and locking of a vehicle brake may be actuated by signals from various sensors/switches inside and outside the vehicle. In a preferred embodiment, the invention relates to a controller that automatically applies a parking brake when certain conditions are sensed in or around the vehicle, as long as the vehicle is not already moving at a speed that is judged as too fast for safe parking brake engagement and, preferably, as long as the sensed condition signals are validated.
2. Related Art
Commercial and public transportation vehicles typically utilize the following types of conventional brakes:
1) Air parking brakes utilize an air-controlled spring system that cooperates with the brake shoes of a vehicle's back wheels. Air parking brake systems exist in commonly-used commercial vehicles, such as trucks, commercial buses, or school buses. The air parking brake system comprises an air source, the spring mechanism, and an air control valve called an “air loading valve” between the air source and the spring mechanism. The air loading valve is controlled only by a manual handle, which is in the vehicle cab on the dashboard or in other positions accessible to the operator. The loading valve manual handle works in a “Pull To Apply” and “Push To Release” manner. Pulling the handle closes the air loading valve, whereby air pressure from the air source is blocked and downstream air pressure is vented so that the springs move to a position that applies the brake. Pushing the handle opens the air loading valve and closes the vent, whereby air is supplied to the spring mechanism so that the springs move to a position that releases the brake.
The loading valve and its handle are located at the dashboard of the vehicle in the cab. The loading valve is very close to the driver, located just under the dashboard, with its handle protruding through the dashboard for access by the driver. Because of this location, the air lines to and from the loading valve travel typically from the rear of the vehicle all the way to the cab and into the space under the dashboard. This creates very long air lines, substantially the entire length of the vehicle, and a very crowded situation under the dashboard. The air lines in large vehicles often are as long as 30 feet or more.
2) Air application brakes, sometimes called “foundation brakes,” are the conventional means, in vehicles with air brakes, to slow and stop the vehicle, for example, during normal “stop and go” driving. The “air application brakes” are operated by a foot-actuated air control valve, which allows incremental application of the brakes depending on how far the operator has pushed on the foot pedal.
3) Mechanical parking brakes utilize a mechanical linkage or a cable, to operatively connect a manual handle in the vehicle cab either to brake shoes at the rear wheels, or to external brake bands or internal brake shoes working with a brake drum mounted on the drive line. The manual handle is typically either a pull-on hand-operated handle, or a push-on foot-operated pedal.
4) Hydraulic “application” (or “foundation”) brakes are the conventional means, in vehicles with mechanical parking brakes, to slow and stop the vehicle during normal driving. A hydraulic application brake system typically comprises a master brake cylinder for applying hydraulic force to brake shoes at the wheels, and a manual foot-pedal for actuating the master cylinder. Pushing on the brake pedal causes the brake cylinder to increase the fluid pressure in the line to the brake shoes at the wheel, which inhibits the rotation of the wheel to an incremental amount depending on how far the operator has pushed on the brake pedal. When the pedal is released, the master cylinder retracts to reduce or eliminate the pressure in the brake line, disengaging the brake shoe pads from contact with the brake drum and thereby allowing unhindered rotation of the wheel. Hydraulic application brakes are used in most family cars, sport utility vehicles, pick-ups, vans, and larger vehicles such as some school buses.
Crowded Equipment and Slow Operation
Conventional brake systems as described above involve manual control/operation by a driver in the cab. Therefore, the conventional systems place substantial amounts of the equipment, for the control/operation in the cab, typically at/in the dashboard or close to the driver's hands or feet. This causes air lines, hydraulic lines, or mechanical linkages to be crowded into spaces in the cab, and the air, hydraulic lines, or cables to extend for long distances from the cab to the brake mechanisms at the wheels. Not only does this result in crowded or inconveniently-placed equipment and lines, but also in delayed actuation of brakes as the forces applied in the cab travel through long fluid lines to the vicinity of the brakes. For example, extra turns or sharper turns in an air parking brake line have been known to delay the braking response, after the driver has moved his arm to pull the air loading valve handle. Such delays can be longer than acceptable according to safety requirement for commercial or passenger vehicles.
Regarding Vehicle Movement during Unsafe Conditions
Conditions may exist in or around a vehicle that make it unsafe for the vehicle to be in motion. Conventional safeguards against vehicle movement when such a condition exists are inadequate, at least in part because the safeguards typically depend on the driver taking appropriate action. This invention, without requiring driver action or involvement, automatically detects such conditions and automatically applies or locks the brakes, thereby preventing potentially unsafe vehicle movement.
Vehicle movement when conditions exist that potentially make such movement unsafe are generally the result of (1) the driver's failure to properly apply or engage the parking brake or application/foundation brake system, (2) a third party's intentional release or interference with the parking brake, or (3) the driver's failure, whether intentional or inadvertent, to detect and/or react to conditions which may make vehicle movement unsafe.
Examples of potentially dangerous conditions where movement of a vehicle may be unsafe include but are not limited to the following:
A driver leaves a vehicle, or is otherwise not in a position to safely operate the vehicle and fails to properly set the parking brake.
A driver attempts to put a vehicle in motion when people are attempting to enter or leaving the vehicle.
A driver attempts to put a vehicle in motion with a door open, wheel chair ramp in use, luggage compartment unlatched, or

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Parking brake control system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Parking brake control system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Parking brake control system will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3332459

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.