Patent ID: 8210277

Claim:
A housing for a power tool having a reduction gear mechanism coupled to a drive source for reducing a rotational output of the drive source, the housing comprising: a first housing half having a first mating surface; a second housing half having a second mating surface configured to be mated with the first mating surface of the first housing half within a plane extending substantially in a lengthwise direction of the power tool, while a gap is formed between the first and second mating surfaces, wherein: each of the first and second housing halves includes an outer frame and an inner wall formed integrally with the outer frame; the inner wall includes a first wall and a second wall; the first walls of the first and second housing halves cooperate with each other to define at least a part of a gear chamber that can receive the reduction gear mechanism therein; the second wall is formed in continuity with the first wall; the outer frames of the first and second housing halves define a first part of the gap; the first walls of the first and second housing halves define a second part of the gap; the second walls of first and second housing halves define a third part of the gap; the second wall of each of the first and second housing halves is connected to the corresponding outer frame in such a manner that the second wall intersects with the outer frame; and the first wall of each of the first and second housing halves is only connected to the outer frame via the second wall, so that the second part of the gap is connected to the first part via the third part; and a capillary action preventing device disposed in the third part of the gap or in a connecting point between the first part and the third part of the gap and constructed to interrupt a path of flow of a liquid caused by a capillary action along at least one of the first, second and third parts of the gap.