| 摘要 |
PURPOSE:To enable a communicating hole for exhausting air to be maintained at a substantially lowermost position, by a method wherein an end part of a dust boot and a housing or a movable shaft engaged with the end part are provided respectively with a projected part and a recessed part which are engaged with each other in a circumferential direction. CONSTITUTION:The recessed part 6b provided at a flange part 6a of a collar 6 fixed to a transmission housing 1 through an oil seal 7 is engaged in the circumferential direction by the projected part 4d provided at the end part 4b on the oil seal side of the dust boot 4. As a result, although the dust boot 4 is twisted with the end part 4b as a fixed end in response to a rotation of a striking rod 2, it is returned to its original state by the elasticity thereof, so that the communicating hole 4c for exhausting air can be maintained at the substantilly lowermost position where it is fitted, irrespective of the deterioration of the end part 4b. Accordingly, even if muddy water penetrates into the dust boot 4 through the hole 4c, it is immediately drained without stagnating in the dust boot 4. |
