Thru-feed lapping apparatus

A power-driven automatic thru-feed lapping apparatus, comprising:

• a generally cylindrical lapping table including a generally circular substantially continuous lapping surface arranged for rotation about a central vertical axis under power provided by a motor;
• first track means for guiding parts having at least one surface to be lapped from an upstream location of such track means along a predetermined path across the lapping surface of the table to a downstream location of such track means, the first track means including a first parts track arranged in a generally straight first line perpendicular to preselected radial direction of the table at predetermined first distance to the center of rotation of the table;
• first commonly-operated multiple escapement means, for selectively blocking progress of parts to be lapped while such parts guided by the first track means, and for selectively releasing parts to proceed along the first track means, such escapement means including first, second and third individual escapement mechanisms spaced from one another along the first track means, with each such escapement mechanism having at least one mechanical stop movable between a blocking position where parts are stopped and a clear position which allows parts to proceed in a forward direction along the first parts track;
• second track means for guiding parts having at least one surface to be lapped from an upstream location of such track means across the lapping surface of the table to a downstream location along such track means, the second track means including a second parts track arranged in a generally straight second line perpendicular to preselected radial direction of the table at predetermined second distance to the center of rotation of the table, the second distance being greater than the first distance, whereby the first and second parts tracks are generally parallel to one another;
• second commonly-operated multiple escapement means, for selectively blocking progress of parts to be lapped while such parts are guided by the second track means, and for selectively releasing parts to proceed along the second track means, such means including first, second and third individual escapement mechanisms spaced from one another along the second track means, with each such escapement mechanism having at least one mechanical stop movable between a blocking position where parts are stopped and a clear position which allows parts to proceed ina forward direction along the second parts track;
• and
• the individual escapement mechanisms of the second escapement means being generally closer to one another than the individual escapement mechanisms of the first escapement means such that the parts to be lapped in the second track means receive approximately the same amount of lapping action by the lapping surface of the table as the parts to be lapped in the first track means.