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A rotary hammer and a power tool. The rotary hammer is operable in an idle mode and a hammer mode and comprises a housing and a barrel positioned in the housing and having a forward portion. A ram is positioned within the barrel and is movable relative to the barrel between hammering positions and a

A rotary hammer and a power tool. The rotary hammer is operable in an idle mode and a hammer mode and comprises a housing and a barrel positioned in the housing and having a forward portion. A ram is positioned within the barrel and is movable relative to the barrel between hammering positions and an idle position. In some aspects, a ram catcher assembly is positioned along the axis adjacent the forward portion of the barrel to releasably hold the ram in the idle position. The ram catcher assembly includes a friction member frictionally engageable with the ram and a damping member at least partially surrounding the friction member. As the ram moves to the idle position with a force, the damping member absorbs at least a portion of the force and the member applies friction to the ram.

대표청구항 ▼

What is claimed is: 1. A power tool comprising: a body housing a motor, including a wall defining an interior portion housing grease, and at least partially defining a labyrinth path, the labyrinth path having an inlet communicating with the interior portion and an outlet communicating with atmosph

What is claimed is: 1. A power tool comprising: a body housing a motor, including a wall defining an interior portion housing grease, and at least partially defining a labyrinth path, the labyrinth path having an inlet communicating with the interior portion and an outlet communicating with atmosphere; and a drive mechanism driven by the motor and supported in the body, the drive mechanism including a shaft extending through the interior portion, the shaft defining an axis and supporting a slinger surface for rotating movement about the axis relative to the wall to prevent the grease from entering the inlet of the labyrinth path. 2. The power tool of claim 1, wherein the axis is substantially aligned with the inlet of the labyrinth path. 3. The power tool of claim 1, wherein the labyrinth path includes at least two turns, each turn being oriented at an angle of at least about ninety degrees. 4. The power tool of claim 1, further comprising a permeable cover positioned along the labyrinth path. 5. The power tool of claim 1, wherein operation of the power tool causes pressure buildup in the interior portion, the pressure being vented from the interior portion through the labyrinth path. 6. The power tool of claim 1, wherein at least a portion of the slinger surface extends beyond the inlet of the labyrinth path in a direction measured along the axis. 7. The power tool of claim 1, wherein the slinger surface extends circumferentially around at least a portion of the shaft and rotates relative to the wall about the axis along an eccentric path. 8. The power tool of claim 1, wherein the shaft includes an end extending through the wall, and wherein the shaft defines a breather port in the end communicating with the labyrinth path. 9. The power tool of claim 8, wherein the slinger surface is positioned adjacent to the breather port. 10. A power tool comprising: a body housing a motor, including a wall defining an interior portion, and at least partially defining a labyrinth path, the labyrinth path having an outlet communicating with atmosphere and an inlet communicating with the interior portion along an axis, grease being housed in the interior portion; and a drive mechanism driven by the motor and including a slinger surface supported in the interior chamber for movement relative to the wall to prevent the grease from entering the inlet of the labyrinth path, at least a portion of the slinger surface extending beyond the inlet of the labyrinth path in a direction measured along the axis. 11. The power tool of claim 10, wherein the drive mechanism includes a shaft extending through the interior portion, and wherein the slinger surface is supported on the shaft adjacent to the inlet for rotating movement about the axis relative to the housing. 12. The power tool of claim 11, wherein the shaft includes an end extending through the wall, and wherein the shaft defines a breather port in the end communicating with the labyrinth path. 13. The power tool of claim 11, wherein the slinger surface extends circumferentially around at least a portion of the shaft and rotates relative to the housing about the axis along an eccentric path. 14. The power tool of claim 10, wherein the labyrinth path includes at least two turns, each turn being oriented at an angle of at least about ninety degrees. 15. The power tool of claim 10, further comprising a permeable cover positioned along the labyrinth path. 16. The power tool of claim 10, wherein operation of the power tool causes pressure buildup in the interior portion, the pressure being vented from the interior portion through the labyrinth path. 17. A power tool comprising: a body housing a motor, including a wall defining an interior portion, and at least partially defining a labyrinth path, the labyrinth path having an outlet communicating with atmosphere and an inlet communicating with the interior portion and defining an axis, grease being housed in the interior portion; and a drive mechanism driven by the motor and including a slinger surface rotatable about the axis relative to the housing along an eccentric path to prevent the grease from entering the inlet of the labyrinth path. 18. The power tool of claim 17, further comprising a shaft extending through the interior portion, and wherein the slinger surface is supported on the shaft adjacent to the inlet for rotating movement about the axis relative to the housing. 19. The power tool of claim 18, wherein the shaft includes an end extending through the wall, and wherein the shaft defines a breather port in the end communicating with the labyrinth path. 20. The power tool of claim 19, wherein the slinger surface is positioned adjacent to the breather port. 21. The power tool of claim 18, wherein the slinger surface extends circumferentially around at least a portion of the shaft and rotates relative to the housing about the axis along an eccentric path. 22. The power tool of claim 17, wherein the labyrinth path includes at least two turns, each turn being oriented at an angle of at least ninety degrees. 23. The power tool of claim 17, further comprising a permeable cover positioned along the labyrinth path. 24. The power tool of claim 17, wherein operation of the power tool causes pressure buildup in the interior portion, the pressure being vented from the interior portion through the labyrinth path. 25. The power tool of claim 17, wherein the power tool is a rotary hammer having a chuck for supporting a tool element, and wherein the drive mechanism is operable to reciprocate the tool element along a substantially linear travel path relative to the tool body. 26. A power tool comprising: a body housing a motor, including a wall defining an interior portion housing grease, and including an opening extending through the wall and communicating between the interior portion and atmosphere; and a drive mechanism driven by the motor and supported in the body, the drive mechanism including a shaft extending through the interior portion, the shaft defining an axis and supporting a slinger surface for rotating movement about the axis relative to the wall to prevent the grease from entering the opening in the wall, the axis being substantially aligned with the opening. 27. A power tool comprising: a body housing a motor, including a wall defining an interior portion housing grease, and including an opening extending through the wall and communicating between the interior portion and atmosphere; and a drive mechanism driven by the motor and supported in the body, the drive mechanism including a shaft extending through the interior portion, the shaft defining an axis and supporting a slinger surface for rotating movement about the axis relative to the wall to prevent the grease from exiting the interior portion through the wall, at least a portion of the slinger surface extending toward the opening in the wall in a direction measured along the axis.