摘要 |
764,800. Hydraulic brakes. BENDIX AVIATION CORPORATION. Feb. 10, 1955 [Feb. 19, 1954], No. 4034/55. Addition to 718,754. Class 103 (1). A pneumatic servo - unit for hydraulic brakes of the kind wherein the pressure in the hydraulic cylinder 301 is transmitted back through the interior of the hollow plunger rod 320 to the air control valve to provide " feel " is characterized in that the transmission is carried out by a first and second reaction means operated successively as the pressure increases in the cylinder 301. As shown in Fig. 2, the pressure in the cylinder 301 is operative at all times to apply a thrust through the resilient cap 258 at one end to a central rod 302, the other end of which is in contact at all times with the valve control member 238. When pressure in cylinder 301 has increased to a certain value, the cap 258 presses the end of rod 302 back through its sleeve 304 and then forces the latter back so as to compress spring 318 against its abutment 314 so that the end of sleeve 304 also bears against the member 238. Feel is thus transmitted to the operator in two stages with an intensity depending on the relative cross-sectional areas of the rod 302 and sleeve 304. Reference has been directed by the Comptroller to Specification 678,248. |