Grinding head for machining constant internal profiles

An attachment for a grinding machine having a movable work table and a rotary grinding wheel rotatable about a first axis the attachment comprising a support frame for mounting on said table, first means carried by the support frame for holding a component upon an internal peripheral surface of which a profile is to be machined, said first means rotating said component about a second axis parallel to the axis of rotation of said grinding wheel, second means carried by the support frame for holding a master having an internal profile corresponding to the desired profile of the component, said second means rotating said master about an axis coincident with said second axis, a detector roll engageable with the internal profile of said master, said detector roll being of varying diameter throughout its axial length, mounting means for said detector roll, said mounting means being arranged to permit rotation of said roll about a third axis inclined relative to the second axis by an amount such that the line of contact between the roll and said internal profile extends paralled to said second axis, connecting means for transmitting movement between said first and second means whereby homothetic motion will be imparted to said first means as a result of movement of said second means by the interaction of the roll and the internal profile of the master, said mounting means being adjustable so that when the diameter of said grinding wheel is changed as a result of dressing or changing the wheel the homothetic relationship of the motion of the grinding wheel and the detector roll is maintained.