Abstract: A power drill has a housing holding a planetary gear transmission and a motor. A drive stem rotatable in the housing about the axis is rotationally coupled to the planet carrier, and a chuck body is rotatable on the housing. A driver axially bearing on the jaws is axially shiftable to position jaws in the chuck, and a sleeve threaded to the driver is rotatable to position the jaws in the chuck body. The drive stem can be coupled either to the chuck body for rotating a tool held by the jaws in a screw or drill mode or to the sleeve in a tighten/loosen mode for tool exchange. A first spring bears axially inward against a front face of the transmission ring gear with an adjustable axially inwardly directed force, and a second spring bears axially against a rear face of the ring gear.

Abstract: A drill-chuck body is rotatable about an axis and formed with a plurality of passages opening axially rearward at a rear face of the body and radially outwardly at windows in a side of the body. Jaws displaceable between front and rear positions in the passages each have a row of teeth exposed radially outwardly at the respective windows. A tightening ring rotatable about the axis is formed with an internal screwthread engaged at the windows with the teeth such that rotation of the ring moves the jaws between the front and rear positions. A tightening sleeve fitted around and coupled rotationally to the tightening ring extends axially rearward past the windows. This brace ring is radially inwardly engaged with the body and engages radially outwardly between the windows and the rear face with the tightening sleeve so as to coaxially center it on the body.

Abstract: A drill-chuck body is rotatable about an axis and formed with a plurality of passages opening axially rearward at a rear face of the body and radially outwardly at windows in a side of the body. Jaws displaceable between front and rear positions in the passages each have a row of teeth exposed radially outwardly at the respective windows. A tightening ring rotatable about the axis is formed with an internal screwthread engaged at the windows with the teeth such that rotation of the ring moves the jaws between the front and rear positions. A tightening sleeve fitted around and coupled rotationally to the tightening ring extends axially rearward past the windows. This brace ring is radially inwardly engaged with the body and engages radially outwardly between the windows and the rear face with the tightening sleeve so as to coaxially center it on the body.

Abstract: A typical power drill has a housing, a drive spindle that can be driven by a motor, and a chuck including a chuck body in which jaws are guided that are adjustable by a threaded connection provided between a driver and a threaded sleeve. A drill spindle and an axially displaceable drive stem can be driven by a motor from its end facing the drive spindle by planetary gearing gearing composed of a sun gear, a planet carrier supporting planet gears, and a ring gear, and comprising a control element. A locking element and a gripping element are provided parallel to the force transmission chain of the drive stem, which elements are rotationally fixed to the housing and can be moved axially by adjusting the control element between the operating modes of the power drill so as to vary the torque acting on the drive stem.