Vehicle wheel brake

Claim 1

A brake device for a wheel, the wheel having a hub mounted for rotation about an axle, the hub being characterized by at least a first lateral face lying in a plane perpendicular to the axis about which the wheel rotates, the brake device comprising: a first layer of lining material having a high coefficient of friction disposed on at least part of the hub first lateral face; annular brake plate means, said brake plate means being axially movable with respect to the hub and having a first face which is normally in opposed parallel spaced relationship to said first layer of said lining material on the hub first lateral face, said brake plate means being coaxial with the axle; a second layer of lining material having a high coefficient of friction disposed on at least part of said brake plate means first face so as to normally be in registration with and spaced from said first layer of lining material; cylinder defining means, said cylinder defining means having a first cylindrical bore of first diameter and a second cylindrical bore of greater diameter than said first bore, said first and second bores being in communication with one another and being both coaxial with the axle, the junction between said bores defining a radially extending shoulder, said cylinder defining means being disposed inwardly toward the axle with respect to said brake plate means; a plurality of radially extending ribs rigidly connecting said cylinder defining means to said brake plate means, said ribs in part defining a plurality of passages between said plate means and said cylinder defining means; a piston having a cylindrical body portion and a cylindrical first portion of increased diameter extending from said body portion, said piston body portion diameter being commensurate with the diameter of said cylinder defining means first bore whereby said piston may be operatively associated with said cylinder defining means with said first portion being disposed in said second bore and said piston body portion extending through said first bore, said piston further having a cylindrical bore commensurate in diameter with the diameter of the axle whereby the piston may be installed on the axle; means for pReventing translational movement of said piston on the axle; stop means affixed to said piston body portion for limiting translational movement of said cylinder defining means with respect to said piston; resilient seal means disposed between said cylinder defining means and said piston; and means for delivering fluid under pressure to said cylinder defining means second bore between said cylinder defining means shoulder and said piston whereby said cylinder defining means may be caused to move axially to produce contact between said first and second layers of lining material.