| 摘要 |
<p>An adjustable annular exhaust air directing member (120) having a radially extending exhaust air outlet (122) is disposed in communicating relation with the exhaust opening (66) allowing air displaced into the exhaust opening (66) during the return stroke of the piston assembly (20) to communicate with the radially extending exhaust opening (122). Mounting structure (130, 132) serves to mount the exhaust air directing member on the frame structure (12) above the main valve assembly (38) for free rotational movement about the axis of the cylinder (18). A pair of O-rings are provided which act between the exhaust air directing member (120) and the frame structure (1) to ensure that air displaced into the exhaust opening (66) is discharged into the atmosphere through the radially outwardly extending exhaust outlet (122) in a direction determined by the rotational position of the exhaust air directing member in any rotational position into which it is manually moved.</p> |
