American Anti-lock Brake Device
Page 59

If you've noticed an error in this article please click here to report it so we can fix it.
NAEANS to reduce the tendency for the IVA wheels of an air-braked heavy vehicle to lock have been developed by the Hydro-Aire Co., California, U.S.A. The system is known as the Hytrol, and its units control each wheel_ separately so that any out-of-balance braking forces or tendencies to lock or skid can be detected before they take effect. Correction may be made to the pressure of the air supply actuating any brake.
Hydro-Aire have been producing a
In addition to guarding against excessive skidding, the Hytrol will automatically provide compensated braking in the event of a driver applying his brakes on a bend, and will similarly compensate for icy spots on a road surface and the use of brake linings of different coefficients of friction on the brakes on any axle.
The equipment consists of an electromechanical detector unit, which is carried on the wheel hub. This unit "anticipates " a skid or a locked wheel before it can occur, and is electrically linked to a valve introduced into the air-pressure system immediately ahead of the brakeactuating diaphragms.
Thus a detector can control the effective air pressure in the operating diaphragm, and the response and operating cycle occurs within 0.07 seconds of the detector unit making a signal.
The system has the advantage of being relatively easy to install, and of introducing the minimum number of nonstandard components into an existing braking system.