Patent ID: 8733220

Claim:
A miter saw, comprising: a rotary-disc assembly; a swing arm assembly rotatably coupled with the rotary-disc assembly; a sliding rod assembly slidably coupled with the swing arm assembly; a cutting head rotatably coupled with the sliding rod assembly around a turning shaft of a head section, wherein the cutting head comprises a sliding fixed-length mechanism for the cutting head which is used to fix the cutting head to a specific position relative to the swing arm assembly; wherein the sliding fixed-length mechanism comprises a fixed-length rod located on the sliding rod assembly and extending along a sliding direction of the cutting head, and a locking device located on the swing arm assembly for locking the fixed-length rod at a specific position; wherein the locking device comprises a locking member mounted on the swing arm and is able to move up and down linearly, a hook rotatably coupled to the swing arm and simultaneously coupled with the locking member by a guide screw, and a return spring arranged between the locking member and the swing arm assembly; wherein a locking groove is arranged at the end of the fixed-length rod; wherein the locking member has three positions relative to the swing arm comprising an upper stop position, a lower stop position, and a locking position where a portion of the hook enters into the locking groove on the fixed-length rod; and wherein when the cutting head is fixed at the specific position and pivoted around the turning shaft to a lowermost cutting position, and an intersecting point between a plane of a supporting surface of a fence and a cutting edge of a saw-blade is located above an intersecting line between the supporting surface of the fence and a supporting surface of a base plate.