| 摘要 |
A chuck has a chuck body formed centered on the chuck axis with an annular array of outwardly directed teeth. A plurality of generally angularly equispaced and radially displaceable jaws on the body can be displaced toward and away from each other by means of a tightening sleeve which is rotatable on the chuck body about the chuck axis. A ratchet pawl is pivoted on this sleeve and has an end engageable with the teeth in a direction so as only to allow rotation of the sleeve and chuck relative to each other in a direction moving the jaws toward each other. A spring is braced between this pawl and the sleeve and urges the sleeve into radial engagement with the teeth. A release ring can be rotated relative to the chuck body between a holding position which allows the spring to press the end of the pawl against the teeth and a releasing position which holds the end of the pawl out of engagement with these teeth. |
