| 摘要 |
A valve comprises a connection plate attached to the housing, such plate having a sealing surface facing into such housing, a flat spool arranged to be able to be reciprocated in a direction parallel to such sealing surface so as to sealingly wipe said surface and to connect together and separate from each other ports opening into said surface, said ports being at the ends of ducts extending through said plate, and means for operating said spool by reciprocating same, said operating means taking the form of wall means defining operating spaces at the ends of the spool, means for passing an operating fluid into said spaces for changing the volume thereof so that when the volume of one space is increased the volume of the other is decreased, said wall means being at least in part secured to said housing, said operating means further defining two operating surfaces at the two ends of said spool, said operating surfaces and said wall means part secured to said housing being connected together by at least one flexible part of such wall means, such flexible part allowing the change in volume to take place by a deformation thereof.
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