Spot-type disc brake with dust cover

Claim 1

THE COMBINATION IN A SPOT TYPE BRAKE OF AN AXLE, A WHEEL ROTATABLE ON THE AXLE, A DISC ROTATABLE WITH THE WHEEL, A STAMPED SHEET METAL PRESSURE UNIT STRADDLING A PORTION OF THE PERIPHERY OF THE DISC, SAID PRESSURE UNIT HAVING AN ANVIL PORTION OF ONE SIDE OF THE DISC AND A CUP PORTION OF THE OTHER SID OF THE DISC, A TORQUE PLATE FIXED TO THE AXLE AND EXTENDING BETWEEN THE ANVIL PORTION AND THE CUP PORTION OF THE PRESSURE UNIT IN POSITION CLOSELY PARALLEL TO THE DISC AND RADIALLY BEYOND THE DISC, THE RADIALLY OUTER END OF THE TORQUE PLATE BEING BIFURCATED, A KEY JOINING THE CUP PORTION AND ANVIL PORTION OF THE PRESSURE UNIT AND SLIDABLY EXTENDING THROUGH THE BIFURCATED END OF THE TORQUE PLATE, A PISTON SLIDABLY MOUNTED IN THE CUP PORTION, A BLOCK OF FRICTION MATERIAL ENGAGING THE PISTON AND MOVABLE BY THE PISTON AGAINST ONE SIDE OF THE DISC, SAID FRICTION MATERIAL EXTENDING SLIDABLY THROUGH A HOLE IN THE TORQUE PLATE, A SECOND BLOCK OF FRICTION MATERIAL IN THE ANVIL PORTION AND MOVABLE AGAINST THE OTHER SIDE OF THE DISC, MEANS FOR SUPPLY FLUID UNDER PRESSURE TO TO CUP PORTION BEHIND THE PISTON, A DUST SHIELD SUBSTANTIALLY COVERING ONE SIDE OF THE DISC AND SURROUNDING THE TORQUE PLATE, MEANS SECURING THE DUST SHIELD TO THE PRESSURE UNIT, AND MEANS PIVOTALLY MOUNTING THE DUST SHIELD IN RELATION TO THE TORQUE PLATE AT A DISTANCE GREATER THAN ABOUT ONE-HALF OF THE DIAMETER OF THE DISC FROM THE PRESSURE INIT TO PROVIDE HINGED MOVEMENT OF THE PRESSUREUNIT TO AND FROM THE DISC.