Method and apparatus for lens turning

A turning attachment comprising:

• (a) support means;
• (b) an intermediate support, said intermediate support pivotally connected with said support means for rotation about a first axis;
• (c) a tool support, said tool support pivotally connected with said intermediate support for rotation about a second axis, said tool support including a cam follower;
• (d) cam support means, said cam support means pivotally connected with said support means for rotation about a third axis, said cam support means including a cam;
• and
• (e) linkage means provided on said cam support means and said intermediate support whereby, movement of said cam plate, in response to movement of said cam follower along said cam surface, moves said intermediate support about said first axis to thereby move said second axis about said first axis.

A turning attachment comprising:

• (a) a base member, said base member including a first pivot means having an axis;
• (b) a first member mounted on said first pivot means for movement about said first pivot axis relative to said base member, said first member including a second pivot means having an axis;
• (c) a second member mounted on said second pivot means for movement about said second pivot axis relative to said first member, said second member including a cam follower means;
• (d) a cam support means including a cam having a cam surface;
• (e) means for interconnecting said cam support means with said base member for rotation about a third axis in response to movement of said cam follower along said cam surface;
• and
• (f) means, provided on said cam support means and said first member, for pivoting said first member about said first axis in response to movement of said cam support means about said third axis to thereby move said second pivot means about said first pivot means.

A turning attachment comprising:

• (a) a base member, said base member including a first pivot and a cam follower, said first pivot means having an axis;
• (b) a first member mounted on said first pivot means for movement about said first pivot axis relative to said base member, said first member including a second pivot means having an axis;
• and
• (c) a second member mounted on said second pivot for movement about said second pivot axis relative to said first member, said second member including a cam surface engageable with said cam follower whereby rotation of said second member about said second pivot axis rotates said first member about said first pivot axis to thereby move said second pivot axis.

A method of forming a surface on workpiece, such as a lens, with a cutting means attached to turning attachment and with means for supporting and rotating said workpiece, said attachment including first and second relatively pivotal members, said cutting means attached to said second member, said first member pivoting about a first axis, said second member pivotally connected to said first member for rotation relative to said first member about a second axis, and means, responsive to the rotation of second member, for simultaneously rotating said first member about said first axis during at least a portion of the movement of said second member about said second axis, said method comprising:

• (a) rotating said workpiece;
• (b) engaging said cutting means with said workpiece;
• (c) rotating said second member about said second axis;
• and
• (d) while rotating said second member about said second axis, rotating said first member about said first axis to rotate said second axis about said first axis to thereby impart a compound movement to said cutting means.