PORTABLE POWER TOOL WITH QUICK BRAKE ASSEMBLY

摘要

A portable power tool comprises a motor (2) having a rotary spindle (6) and a cam brake assembly. The cam brake assembly comprises a brake plate (10) attached to the spindle (6), a brake cam (30) carrying a friction material and formed with at least two cam portions, and a stationary support (50) formed with at least two cam portions at positions corresponding to the cam portions of the brake cam (30). The brake cam (30) is rotatable around the rotation axis of the spindle (6). When the brake cam (30) rotates, by the cam action between the cam portions of the brake cam (30) and the cam portions of the stationary support (50), the brake cam (30) is moved in either of dual directions along the rotation axis of the spindle (6) so that the friction material is moved into contact with the brake plate (10) or away from the brake plate (10).