| 摘要 |
A throttle valve device for a pneumatic power tool comprises a casing ( 10 ) with an air inlet passage ( 11 ), an air outlet passage ( 12 ), a valve chamber ( 13 ) with a main valve seat ( 14 ) and a main valve element ( 15 ), and a manually shiftable activating rod ( 21 ) which is sealingly guided in a lateral guide way ( 19 ) and arranged to engage and displace the main valve element ( 15 ) off the main seat ( 14 ), wherein the activating rod ( 21 ) has a valve portion ( 27,28 ) for co-operation with a secondary valve seat ( 24 ) in the guide way ( 19 ) for controlling a bypass passage ( 23,24,29 ) extending between the inlet passage ( 11 ) and the outlet passage ( 12 ) such that the activation rod valve portion ( 27,28 ) is separated from the secondary valve seat ( 24 ) and opens up the bypass passage ( 23,24,29 ) before the activation rod ( 21 ) engages and displaces the main valve element ( 15 ) off the main seat ( 14 ) when operating the activation rod ( 21 ) in the opening direction.
|
