Hydraulic disc brake

Claim 1

A SPOT DISC BRAKE COMPRISING A HOUSING DEFINING A SLOT ADAPTED TO RECEIVE A ROTATING BRAKE DISC TO BE BRAKED, A CYLINDRICAL BRAKE SHOE DISPOSED IN THE HOUSING ON EACH SIDE OF THE SLOT WITH ITS CIRCULAR FACE EXPOSED IN THE SLOT FOR FRICTIONAL ENGAGEMENT WITH THE BRAKE DISC, SAID BRAKE SHOES BEING COAXIALLY ALIGNED AND RECEIVED IN THE HOUSING FOR FREE ROTATIONAL AND FREE AXIAL MOVEMENT, SAID HOUSING DEFINING A FIRST CYLINDRICAL BORE IN SPACED RELATION FROM THE BRAKE SHOES AND WITH ITS AXIS EXTENDING IN THE SAME DIRECTION AS THE COMMON AXIS OF THE BRAKE SHOES, A PAIR OF SPACED PISTONS SLIDABLY DISPOSED IN THE FIRST BORE, SAID HOUSING DEFINING A SECOND CYLINDRICAL BORE HAVING A CLOSED END, A PISTON SLIDABLY DISPOSED IN THE SECOND BORE IN SPACED RELATION FROM THE CLOSED END OF THE SECOND BORE, SAID HOUSING DEFINING A PASSAGEWAY COMMUNICATING FROM THE SECOND BORE ADJACENT THE CLOSED END THEREOF TO THE FIRST BORE BETWEEN THE PISTONS THEREIN, MEANS OPERABLE EXTERIORLY OF THE HOUSING FOR MOVING THE PISTON IN THE SECOND BORE, A PAIR OF ACTUATING LEVERS ON THE HOUSING, ONE ACTUATING LEVER EXTENDING BETWEEN ONE BRAKE SHOE AND THE PISTON IN THE FIRST BORE ON THE SAME SIDE OF THE HOUSING AS THAT BRAKE SHOE WITH ONE END OPERATIVELY CONNECTED TO THAT BRAKE SHOE AND WITH A PORTION SPACED ALONG THE ACTUATING LEVER FROM THAT END OPERATIVELY CONNECTED TO THAT PISTON IN THE FIRST BORE AND THE OTHER ACTUATING LEVER EXTENDING BETWEEN THE OTHER BRAKE SHOE AND THE PISTON IN THE FIRST BORE ON THE SAME SIDE OF THE HOUSING AS THAT BRAKE SHOE WITH ONE END OPERATIVELY CONNECTED TO THAT BRAKE SHOE AND WITH A PORTION SPACED ALONG THE ACTUATING LEVER FROM THAT END OPERATIVELY CONNECTED TO THAT PISTON IN THE FIRST BORE, PIVOT MOUNTINGS ON THE HOUSING FOR THE ACTUATING LEVERS, SAID PIVOT MOUNTINGS PIVOTALLY MOUNTING THE ACTUATING LEVERS ON THE HOUSING WITH PIVOT AXES TRANSVERSE TO THE COMMON AXIS OF THE BRAKE SHOES AND LOCATED ON EACH ACTUATING LEVER BETWEEN THE OPERATIVE CONNECTIONS OF THE ACTUATING LEVER TO THE BRAKE SHOE AND TO THE PISTON IN THE FIRST BORE, THE PIVOT AXES OF THE ACTUATING LEVERS BEING ALIGNED WITH EACH OTHER IN THE DIRECTION OF THE COMMON AXIS OF THE BRAKE SHOES, EACH SAID ACTUATING LEVER HAVING A PORTION EXTENDING FROM ITS PORTION OPERATIVELY CONNECTED TO THE PISTON IN THE FIRST BORE TO AN END ADJACENT TO AND SPACED FROM THE HOUSING, AND A SCREW THREADEDLY RECEIVED IN THE END OF EACH EXTENSION OF EACH ACTUATING LEVER EXTENDING THROUGH THE ACTUATING LEVER WITH THE AXIS OF THE SCREW TRANSVERSE TO THE PIVOT AXIS OF THE ACTUATING LEVER AND WITH AN END OF THE SCREW BEARING AGAINST THE HOUSING TO PERMIT THE ANGULAR POSITION OF THE ACTUATING LEVER ABOUT ITS PIVOT AXIS TO BE VARIED AND PRESELECTED THROUGH ROTATION OF THE SCREW.