| 摘要 |
A unique bellows seal for sealing valve components, joining sections of pipe together, and the like, includes an elongate, accordion-pleated body having first and second ends and a plurality of axially spaced apart reinforcing rings thereon. The seal is machined from a solid piece of material to produce an elongate, thin-walled tubular section having the reinforcing rings on the outer surface thereof and is then axially compressed to form the accordion-like pleats. In one form of the invention, the seal extends coaxially around the actuator shaft of a valve to seal the actuator shaft relative to the valve body. Threaded portions on the opposite ends of the seal and on spaced portions of the actuator shaft are interengaged to cause reciprocating movement of a valving member when the shaft is rotated. The pitch of the threaded portions may be reversed from one another to effect doubling of the rate of movement of the valving member upon given rotation of the shaft. In a variation of the invention, a pressure responsive piston may be provided on the actuator shaft rather than the threaded portions for causing movement of the shaft and valving member carried thereby.
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