| 主权项 |
1. A slide type circular saw comprising:
a base; a saw unit disposed above the base and configured to be movable upward and downward, the saw unit having a motor-driven rotary saw blade; and a slide bar unit, the slide bar unit comprising:
a first holding portion including a plurality of linear ball bearing parts that are press-fitted in the first holding portion, the plurality of linear ball bearing parts being arranged in an axial direction relative to the first holding portion;a second holding portion including: (1) a linear ball bearing part that is loosely inserted in the second holding portion, and (2) a pair of setscrews screwed at front and rear spots in the second holding portion, respectively, the pair of setscrews directly contacting an outer surface of the linear ball bearing part of the second holding portion, (i) the linear ball bearing part of the second holding portion having a cylindrical shape such that an outer surface of the linear ball bearing part has a circular shape when viewed from an axial direction of the linear ball bearing part and the circular shape extends along an entire length of the linear ball bearing part in the axial direction of the linear ball bearing part, a diameter of the circular shape being the same over the entire length of the linear ball bearing part in the axial direction of the linear ball bearing part, and (ii) an inner surface of the second holding portion having a circular shape when viewed from the axial direction of the linear ball bearing part and the circular shape of the inner surface of the second holding portion extends along an entire length of the second holding portion in the axial direction of the linear ball bearing part, a diameter of the circular shape of the inner surface of the second holding portion being the same over the entire length of the second holding portion in the axial direction of the linear ball bearing part;a pair of slide bars extending parallel to each other in a front-rear direction and each having a front end and a rear end, the pair of slide bars being slidably supported and surrounded by the linear ball bearing parts of the first holding portion and the second holding portion, respectively; anda pair of holders forming a front holder by which the front ends of the slide bars are connected and a rear holder by which the rear ends of the slide bars are connected, wherein: (1) the saw unit is mounted to one of the front and rear holders with the holding portions being fixed to the base, or (2) the saw unit is mounted to the holding portions with the slide bars being fixed to the base, whereby the saw unit is rendered slidable in the front-rear direction, and the pair of setscrews press the outer surface of the linear ball bearing part of the second holding portion against the inner surface of the second holding portion in a direction perpendicular to a plane which contains axes of the slide bars, such that i) upward and downward motions of the linear ball bearing part of the second holding portion are restricted to prevent wobbling of the slide bars during a sliding operation of the saw unit (ii) while a movement of the linear ball bearing part of the second holding portion in the axial direction of the linear ball bearing part is permitted. |
