| 摘要 |
<p>PURPOSE:To set the minimum pressure previously on the pressure control assembly and control pressure within a range of pressure higher than the minimum pressure which is set previously. CONSTITUTION:The pressure control assembly 40 has a previously set means 56 which is arranged where it can not be touched selectively so as to set minimum pressure of the pressure control assembly 40 in advance and a free control means 94 for offering higher pressure selectively. The previously set means 56 can be controlled selectively only when the position where the assembly can not be touched selectively is entered. A shield means 76 prevents a 2nd discharge opening as a pressure relief hole from being blocked and secures the linkage between the 2nd discharge opening 50 and an area of low pressure like atmospheric pressure.</p> |
