초록 ▼

A rotary hammer includes a motor, a spindle coupled to the motor for receiving torque from the motor, a piston at least partially received within the spindle for reciprocation therein, a striker received within the spindle for reciprocation in response to reciprocation of the piston, and an anvil re

A rotary hammer includes a motor, a spindle coupled to the motor for receiving torque from the motor, a piston at least partially received within the spindle for reciprocation therein, a striker received within the spindle for reciprocation in response to reciprocation of the piston, and an anvil received within the spindle and positioned between the striker and a tool bit. The rotary hammer also includes a retainer received within the spindle for selectively securing the striker in an idle position in which it is inhibited from reciprocating within the spindle, and an O-ring positioned between the retainer and the spindle. The O-ring is disposed around an outer peripheral surface of the anvil. The O-ring is compressible in response to the striker assuming the idle position. The compressed O-ring imparts a frictional force on the outer peripheral surface of the anvil to decelerate the anvil.

대표청구항 ▼

1. A rotary hammer adapted to impart axial impacts to a tool bit, the rotary hammer comprising: a motor;a spindle coupled to the motor for receiving torque from the motor;a piston at least partially received within the spindle for reciprocation therein;a striker received within the spindle for recip

1. A rotary hammer adapted to impart axial impacts to a tool bit, the rotary hammer comprising: a motor;a spindle coupled to the motor for receiving torque from the motor;a piston at least partially received within the spindle for reciprocation therein;a striker received within the spindle for reciprocation in response to reciprocation of the piston;an anvil received within the spindle and positioned between the striker and the tool bit, the anvil imparting axial impacts to the tool bit in response to reciprocation of the striker;a retainer received within the spindle for selectively securing the striker in an idle position in which it is inhibited from reciprocating within the spindle; andan O-ring positioned between the retainer and the spindle, and disposed around an outer peripheral surface of the anvil;wherein the O-ring is compressible in response to the striker assuming the idle position, wherein an inner diameter of the O-ring is reduced in response to being compressed, and wherein the compressed O-ring imparts a frictional force on the outer peripheral surface of the anvil to decelerate the anvil. 2. The rotary hammer of claim 1, wherein the spindle includes a step defining an interior annular surface, and wherein the O-ring is positioned between the retainer and the annular surface of the spindle. 3. The rotary hammer of claim 1, wherein the O-ring is a first O-ring, and wherein the retainer includes a circumferential groove in an inner peripheral surface of the retainer, anda second O-ring positioned within the circumferential groove, wherein the striker is engageable with the second O-ring when assuming the idle position. 4. The rotary hammer of claim 3, wherein the second O-ring defines an inner diameter, and wherein the striker includes a nose portion defining an outer diameter greater than the inner diameter of the second O-ring. 5. The rotary hammer of claim 4, wherein the nose portion of the striker is engageable with the second O-ring when assuming the idle position. 6. The rotary hammer of claim 1, wherein the retainer is movable within the spindle between a first position, in which a light preload is applied to the O-ring, and a second position, in which a compressive load is applied to the O-ring greater than the preload. 7. The rotary hammer of claim 6, wherein the retainer is movable from the first position to the second position in response to the striker impacting the retainer. 8. The rotary hammer of claim 1, wherein the piston includes an interior chamber, and wherein the striker is at least partially received within the interior chamber. 9. The rotary hammer of claim 1, further comprising an air pocket positioned between the piston and the striker, wherein expansion and contraction of the air pocket induces reciprocation of the striker.