초록 ▼

The drill includes the usual tool spindle driven by reversible motor, and conventional chucking jaws which rotate with the spindle. The jaws are surrounded by an actuator which is drivingly connected to the jaws, and normally rotates with the jaws when the drill is in use. A manually operable contro

The drill includes the usual tool spindle driven by reversible motor, and conventional chucking jaws which rotate with the spindle. The jaws are surrounded by an actuator which is drivingly connected to the jaws, and normally rotates with the jaws when the drill is in use. A manually operable control member on the housing is movable between two operating positions in each of which it holds the actuator against rotation, and consequently causes the spindle to move the jaws to bit-locking or bit-releasing positions, depending upon the direction or rotation of the spindle. Whenever the control member is moved from one to the other of its positions it switches the direction of rotation of the motor. A projection on the control member is releasably engagable selectively in a matching recess in the actuator to impart static loading to the jaws during movement thereof to their bit-locking positions, or in a larger recess in the actuator to impart dynamic loading to the chucking jaws during movement thereof to bit-releasing positions. Safety means is provided for preventing accidental movement of the control member from one to the other of its positions during use of the drill.

대표청구항 ▼

In an electric hand drill of the type having in its housing a reversible electric motor, a tool spindle rotatable selectively in opposite directions by said motor, and a plurality of chucking jaws surrounding one end of said spindle selectively for rotation therewith, and for movement relative to sa

In an electric hand drill of the type having in its housing a reversible electric motor, a tool spindle rotatable selectively in opposite directions by said motor, and a plurality of chucking jaws surrounding one end of said spindle selectively for rotation therewith, and for movement relative to said spindle for releasably securing a tool bit in a bore in said one end of the spindle, a device for selectively connecting said jaws to said motor for movement thereby between bit-locking and bit-releasing positions, respectively, comprising a chuck actuator member rotatably mounted on said spindle and drivingly connected to said jaws normally to rotate with said jaws and said spindle relative to said housing, and manually operable control means on said housing for selectively securing said actuator member against rotation with said spindle, whereby rotation of said spindle relative to said actuator member causes said jaws to be moved to bit-locking positions, when said spindle is rotated in one direction, and to bit-releasing positions, when said spindle is rotated in the opposite direction, said control means being operative to effect a static loading of said jaws by said spindle when the spindle is rotated by said motor in said one direction, and to effect a dynamic loading of said jaws by said spindle, when the latter is rotated by said motor in said opposite direction. A hand drill comprising a housing containing a rotatable tool spindle, a reversible electric motor for driving the spindle, and a movable chucking mechanism on said spindle operable releasably to lock a tool bit in the spindle, coupling means for releasably connecting said chucking mechanism to said housing, including a control member movable selectively to first and second positions, respectively, to effect movement of said mechanism toward a bit locking position, when said motor drives said spindle in one direction, and toward a bit releasing position, when said motor drives said spindle in the opposite direction, means connected to said control member for operation thereby and operative automatically to cause said motor, when energized, to rotate said spindle in said one direction, when said control member is in said first position, and to rotate said spindle in said opposite direction, when said control member is in said second position, a handle on said control member for manipulating said member manually between said first and second positions, and safety means interposed between said handle and said control member and operative to resist movement of said member to either of its first and second positions thereby to prevent accidental connection of said motor to said chucking mechanism during normal use of the drill.