Rotary machining apparatus

Apparatus for machining a flat surface on a workpiece comprising:

• a frame;
• an annular wheel and means for rotatably mounting said wheel to said frame about a predetermined axis of rotation;
• a plurality of circumferentially spaced cutting members mounted to one axial surface of said wheel;
• a workpiece holding fixture mounted to said frame at a position open to, spaced from and axially aligned with said one axial surface of said wheel, said fixture including means for holding the workpiece with the surface to be machined adjacent said one surface of said wheel;
• means for continuously rotating said wheel;
• means for selectively axially moving the fixture toward said wheel whereby said cutting members engage and machine said workpiece surface,
• wherein said cutting members are broaching tools which protrude axially outwardly from said wheel in a progressively increasing amount around the circumfery of said one surface of said wheel in a direction opposite from the direction of rotation of said wheel, said broaching tools extending only around a portion of the circumfery of said one surface of said wheel thus forming an open area on said one wheel surface having a tangential length greater than the width of the workpiece,
• wherein said means for axially moving said workpiece further comprises means for incrementally moving said workpiece toward said wheel surface during each revolution of said wheel when said workpiece is aligned with the open area of said wheel surface, and
• wherein said cutting members in the circumferential area adjacent said open area of said wheel in the direction of rotation of said wheel are finish cutting members, said apparatus further comprising means for axially selectively retracting said finish cutting members away from said workpiece and for axially extending said finish cutting members toward and into engagement with said workpiece during the final incremental rotational cutting cycle for a given workpiece.