| 摘要 |
<p>1,202,744. Fluid pressure brakes. ROBERT BOSCH G.m.b.H. 6 Oct., 1967 [14 Oct., 1966], No. 45768/67. Headina F2F. A brake booster for a motor vehicle comprises a housing 1 divided into two cylinders having respective pistons 10, 11 coupled together by a tube 13, the high pressure side of each piston 10, 11 being shaped to correspond with that of the adjacent cylinder end 53, 54 so as to minimize the minimum cylinder capacity, a vacuum source 12 being coupled to the low pressure side of each cylinder, air being admissible to the high pressure side under control of a valve 24 coaxial with the tube 13, the cross-sectional area of the passage 23 by which the air is admitted being substantially equal to that of the valve 24 in its fully open state. As described, three levers 42 carried by a pin 32 are loosely attached at 43 to piston 11; a disc 45, also attached to piston 11 being coupled to the power transmission rod 49 of a master cylinder. The inlet manifold of the engine is coupled at 12 to the low pressure side of the left hand cylinder and, via an annular space 9, to that of the right hand cylinder. The high pressure side of the two cylinders are coupled together via a passage 23 and radial corrugations 19 in piston 11. The pistons 10, 11 are welded to the tube 13. On depression of the brake pedal 36, a tube 20 is moved to the left, until the end of a tube 30 engages a member 25, interrupting the connection between the high and low pressure sides of the cylinders. Further depression of pedal 36 opens valve 24 which admits air via tubes 20 and passage 23 to the high pressure side of the pistons 10, 11, deflecting them to the left against the bias of spring 48, valve 24 closing when equilibrium is reached. The cylinder 3 may be located within cylinder 2 by radial ribs or, as shown, by a plurality of humps 7, 8.</p> |
