Patent ID: 6949015

Claim:
A machining apparatus comprising: a rotating spindle mounted rotatably, a rotating drive source for rotationally driving said rotating spindle, a rotary tool detachably mounted on said rotating spindle, and at least one screwed member screwed to said rotating spindle for mounting said rotary tool on said rotating spindle, wherein a selective rotation inhibiting means is disposed for selectively inhibiting rotation of said rotating spindle, and said selective rotation inhibiting means includes at least one stop concavity formed in an outer peripheral surface of said rotating spindle, and a stop member to be selectively located at an operating position where said stop member engages said stop concavity, and a nonoperating position where said stop member recedes from said stop concavity, wherein said selective rotation inhibiting means further includes an accommodation member having, formed therein, an accommodation hole having an opening opposed to the outer peripheral surface of said rotating spindle, said stop member is slidably accommodated in said accommodation hole, and when said stop member is located at said operating position, a front end portion thereof partly protrudes from said opening of said accommodation hole, while when said stop member is located at said nonoperating position, a substantial whole thereof is accommodated in said accommodation hole, and wherein said selective rotation inhibiting means further includes elastic biasing means for elastically biasing said stop member to said nonoperating position, and forced slide means for selectively sliding said stop member to said operating position against an elastic biasing action of said elastic biasing means.