Chuck mechanism for detachably connecting impeller shaft and drive unit

Abstract

Chuck mechanisms quickly connect and enable quick disconnection of an impeller shaft of a mixer from the drive shaft of the motor unit. A spindle has a keyway which enables a key, either a detent key which is movable in the keyway or a key which is provided by pins extending from the shaft, to be aligned in locking position where the key transfers the thrust from the spindle to the shaft or an unlocked position where the shaft is rotated out of the locking position and may be removed from the spindle. The key is retained in locking position by an outer sleeve or collar having a slot which enables the key to move away from the shaft when the shaft is rotated to the unlocked position. When the collar is rotated to move the slot away from the key, the key is locked against outward movement. The keyway may be sufficiently large to enable the flat on the shaft to tilt the key so as to provide wedging action of the key against the spindle sleeve and tighten the shaft on the sleeve so as to preclude slipping when greater torque is needed by the mixing impeller. In another embodiment, a tapered bolt is used in a cross-bore through the spindle sleeve, which bolt and a flat with a cylindrical undercut define a keyway. A tapered shoulder portion of a bolt which extends into the keyway defines a guide which permits the shaft to be inserted only with the flat in alignment with the cross-bore and keys the sleeve to the shaft when the bolt is screwed into the cross-bore.