| 摘要 |
<p>904,431. Copy-milling. HAYES ENGINEERS (LEEDS) Ltd. Oct. 6, 1960 [Oct. 26, 1959], No. 36166/59. Class 83 (3). An hydraulic valve unit comprises a hollow valve element 2 and a stylus carrier 9 laterally movable in a housing 3, and a series of plungers 29 arranged to operate the element and being controlled by hydraulic pressure regulated by a part 15 of the stylus carrier. The element is restrained from axial or angular movement by a flange 4 running between balls 5, the degree of freedom being determined by balls 32 adjusted by a sleeve 31 and a nut 30. The flange is urged by spring-pressed plungers against the rods 7 of two valves, each controlling an hydraulic motor. The stylus carrier 9 passes through the element and has a flange 10 guided by balls 11 and centralized by spring- loaded plungers. The stylus 13 is mounted in a socket 12 which can move laterally a predetermined distance before deflecting the element. The control part 15 is mounted by a selfaligning ball bearing and is surrounded by twelve chambers 17, each bearing an inlet port 19b slightly smaller than an outlet 18. The inlet port 19b is formed in a plunger 19a but may be formed simply by an orifice 19. Fluid leaving the outlets is confined by seals 24, 25 and exhausted through a pipe 26. The direction of movement of the element 2 is determined by the particular one of the chambers 17 to which each plunger is connected, closure of a chamber 17 by the part 15 causing movement of the associated plunger 29 towards the element. The connections between the chambers 17 and the plungers 29 may be mounted on a rotatable ring to enable the direction of traverse of the cutter to be altered relatively to the direction of the template or, by partly moving the ring, to render the tracer inoperative. The carrier 9 may be hollow and contain an axiallymovable rod for a depth control valve.</p> |
