Clutch for rotary power tool and rotary power tool incorporating such clutch

A clutch for a rotary power tool having a housing, a spindle rotatably mounted within the housing, and a motor for causing rotation of the spindle about a first axis, the clutch comprising:

• a first clutch member adapted to be mounted to the spindle and to rotate therewith and slide relative thereto in a direction substantially parallel to said first axis;
• first biasing means adapted to act between said spindle and said first clutch member for biasing said first clutch member towards a stop;
• a second clutch member having a first condition in which said second clutch member engages said first clutch member and rotates therewith, and a second condition in which said second clutch member can move relative to said first clutch member;
• second biasing means adapted to act between said first and second clutch members for urging said second clutch member towards said first condition;
• and
• at least one resilient stop member adapted to engage said first clutch member at said stop.

A rotary power tool comprising:

• a housing;
• a spindle rotatably mounted within the housing, the spindle including a first axis and a first cooperating portion, the first cooperating portion including a first friction surface;
• a motor for causing rotation of said spindle about an axis;
• and
• an overload clutch including:
• a stop mounted to the spindle;
• a first clutch member mounted to the spindle so as to be rotationally fixed to the spindle and axially slideable relative to the spindle, the first clutch member having a second cooperating portion engaged with the first cooperating portion, and the second cooperating portion includes a second friction surface inclined relative to the first axis, and the second friction surface engages the first friction surface when the first clutch member moves axially relative to the spindle;
• a first spring located between the spindle and the first clutch member for biasing the first clutch member towards the stop;
• a second clutch member mounted around the spindle and axially movable between a first position and a second position, and wherein the first position the second clutch member engages the first clutch member and rotates therewith, and wherein the first position the second clutch member is rotatable relative to the first clutch member;
• and
• a second spring located between the first clutch member and the second clutch members for biasing the second clutch member towards the first position.

A rotary power tool comprising:

• a housing;
• a spindle rotatably mounted within the housing, the spindle including a radially outer surface and the outer surface defining a trough having longitudinal walls that taper at a first angle along the length of the trough;
• a motor for causing rotation of said spindle about an axis;
• and
• an overload clutch including:
• a stop axially fixed on the spindle;
• a slider sleeve mounted around the spindle, the slider sleeve including a radailly inner surface and a radailly inward spline, the spline having longitudinal walls tapering at substantially first angle and slidably engaging the walls of the trough so that the slider sleeve is connected to the spindle in a rotationally fixed and axially slideable relative arrangement;
• a first spring acting between the spindle and the slider sleeve for biasing the slider sleeve towards the stop;
• a drive gear rotatably mounted around the spindle and the slider sleeve and axially movable relative to the slider sleeve between a first position and a second position, and wherein the first position the drive gear driveably engages the slider sleeve and rotates therewith, and wherein the second position the second clutch member is rotatable relative to the slider sleeve;
• and
• a second spring located between slider sleeve and the drive gear for biasing the drive gear towards the first position.