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US 7,731,208 B2Granted
Tag axle operating system
OwnerBrooks Stronginventor
Life of this patent
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OwnerBrooks Stronginventor
Estimating the term…
A tag axle operating system comprises a gas circuit with gas at a prescribed pressure and a hydraulic circuit that delivers hydraulic fluid pressure to raise and establish the tag axle in an inactive condition and to lower and establish the tag axle in an active condition. The hydraulic circuit establishes a prescribed hydraulic pressure opposing the gas pressure and a resulting force forcing the tag axle tires to bear against a road surface and the tag axle to accept a predetermined load. A brake valve allows air pressure delivery to operate tag axle air brakes while the prescribed hydraulic pressure is maintained and prevents such delivery to disable the brakes when the prescribed hydraulic pressure is relieved. And the hydraulic circuit operates to relieve the prescribed hydraulic pressure to relieve the force on the tag axle and disable the brakes when the tag axle experiences a predetermined tilt angle.
A tag axle operating system for a tag axle having wheels with tires and air brakes wherein the tag axle is suspended from a motor vehicle and is raised and lowered by pivotal movement about a first axis by operation of parallel-arranged hydraulically-operated actuators and can also pivot about a second axis located equidistant from the tag axle wheels and laying in a plane at right angles to the first axis, said system comprising a closed gas circuit charged with a gas at a prescribed gas pressure, a hydraulic circuit adapted to deliver hydraulic fluid under pressure to the actuators to raise and establish the tag axle in an inactive condition and to lower and establish the tag axle in an active condition, said hydraulic circuit adapted when the tag axle is in said active condition to establish a prescribed hydraulic operating pressure opposing the gas pressure and a resulting force on the tag axle forcing the tires to bear against a road surface and the tag axle to accept a predetermined load, a brake valve adapted to allow air under pressure to be delivered to operate the air brakes while said prescribed hydraulic operating pressure is maintained and to prevent such delivery to thereby disable the air brakes when said prescribed hydraulic operating pressure is relieved, and said hydraulic circuit adapted while the tag axle is in said active condition to relieve said prescribed hydraulic operating pressure and thereby relieve the force on the tag axle and disable the air brakes when the tag axle experiences a predetermined tilt angle when pivoting about the second axis.
A tag axle operating system for a tag axle having wheels with tires and air brakes wherein the tag axle is suspended from a motor vehicle and is raised and lowered by pivotal movement about a first axis by operation of parallel-arranged hydraulically-operated actuators and can also pivot about a second axis located equidistant from the tag axle wheels and laying in a plane at right angles to the first axis, said system comprising a closed gas circuit charged with a gas at a prescribed gas pressure, a hydraulic circuit including electrically-operated up valve means and down valve means, said up valve means adapted when supplied with electrical power to provide for delivery of hydraulic fluid under pressure to the actuators to raise and establish the tag axle in an inactive condition, said down valve means adapted when supplied with electrical power to provide for the delivery of hydraulic fluid under pressure to the actuators to lower and establish the tag axle in an active condition, said hydraulic circuit adapted when the tag axle is in said active condition to establish a prescribed hydraulic operating pressure opposing the gas pressure and a resulting force on the tag axle forcing the tires to bear against a road surface and the tag axle to accept a predetermined load, an electrically-operated brake valve adapted when supplied with electrical power to allow delivery of air under pressure to operate the air brakes and when without electrical power prevent such delivery to thereby disable the air brakes, pressure responsive switch means adapted to deliver power to said brake valve only while said prescribed hydraulic pressure is maintained, and tilt sensor switch means adapted while the tag axle in said active condition to effect delivery of electrical power to said up valve means while said down valves are receiving power to thereby relieve said prescribed hydraulic operating pressure and thereby relieve the force on the tag axle and disable the air brakes when the tag axle experiences a predetermined tilt angle when pivoting about the second axis.
Dependencies are inferred from the claim text.