| 摘要 |
<p>1468377 Etching USS ENGS & CONSULTANTS Inc 8 March 1974 [8 March 1973] 10546/74 Heading B6J An internal taper is formed in the walls of a sleeve-like body S, Figs. 1 and 2, by exposing them to an etching solution which forms a pool P within the body, the level of the pool surface being gradually changed. The pool is formed by pumping etchant from a tank 12 through pipes 16, 19, and bores 30, 31 in a plate 32, up into the sleeve S, which is secured to the plate. The etchant returns to the tank by overflow into a telescopable member 44, and the level of the pool is determined by the level of the top of the member 44. The member 44 is raised and extended by a wire 51 attached to a winch mechanism comprising a motor driving a spindle formed with a helical groove in which the wire runs, and the diameter of the spindle varies from one end to the other in such a way as to control the height of the pool to take account of variation in temperature and strength of the etchant and produce a uniform taper.</p> |
