# US 2021/0121995 A1 · Method of grinding and turning a workpiece > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0121995 A1 - Document ID: US20210121995A1 - Status: Published application - Kind: A1 - Application number: 17/073,614 - Filed: 2020-10-19 - Published: 2021-04-29 - Earliest claimed: 2019-10-24 - Assignees: Fives Landis Limited - Applicants: Fives Landis Corp. - Inventors: Timothy William Hykes; Joel Kym Metzler; Joseph Robert Needham - Web page: https://patentgrep.com/patent/US20210121995A1 ## CPC - B24B 19/06: for grinding races, e.g. roller races - B24B 5/04: for grinding cylindrical surfaces externally (grinding combined cylindrical and conical surfaces B24B5/14) - B24B 5/307: Means for supporting work - B23Q 3/152: Rotary devices - B23Q 2017/001: {Measurement or correction of run-out or eccentricity} - B24B 41/061: {axially supporting turning workpieces, e.g. magnetically, pneumatically} - B24B 49/00: Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation (B24B33/06, B24B37/005 take precedence; if applicable to other machine tools, B23Q15/00 - B23Q17/00 take precedence) - G05B 19/402: characterised by control arrangements for positioning, e.g. centring a tool relative to a hole in the workpiece, additional detection means to correct position (G05B19/19 takes precedence) - G05B 2219/49313: Machining about eccentric center different from rotational center of workpiece - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - B23Q: DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING (tools of the kind used in lathes or boring machines B23B27/00); MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) ## Abstract A method of grinding or turning a workpiece, such as a bearing workpiece, involves several steps. One step includes locating the bearing workpiece on a chuck with an axis of rotation of the chuck positioned off-center relative to an axis of the bearing workpiece. Another step includes determining an offset between the chuck's axis of rotation and the bearing workpiece's axis based on the off-center position between the chuck's axis of rotation and the bearing workpiece's axis. Yet another step includes determining a path of engagement of a grinding wheel relative to the bearing workpiece based on the offset previously determined between the chuck's axis of rotation and the bearing workpiece's axis. ## Claims ### Claim 1 A method of grinding a metal workpiece having at least one annular portion, the method comprising: locating the workpiece on a chuck with an axis of rotation of said chuck positioned off-center relative to an axis of the workpiece at the at least one annular portion; determining an offset between the axis of rotation of the chuck and the axis of the workpiece as a result of the off-center position between the axis of rotation of the chuck and the axis of the workpiece; and determining a path of engagement of a grinding wheel relative to the workpiece based on the determined offset between the axis of rotation of the chuck and the axis of the workpiece. ### Claim 2 (depends on 1) The method as set forth in claim 1, wherein the workpiece is a bearing workpiece. ### Claim 3 (depends on 2) The method as set forth in claim 2, further comprising engaging the bearing workpiece with the grinding wheel at an outer diameter of the bearing workpiece, at an inner diameter of the bearing workpiece, at a raceway of the bearing workpiece, at a rib of the bearing workpiece, at a chamfer of the bearing workpiece, or at a groove of the bearing workpiece. ### Claim 4 (depends on 1) The method as set forth in claim 1, wherein locating the workpiece on said chuck comprises engaging the workpiece with at least one centering vee. ### Claim 5 (depends on 1) The method as set forth in claim 1, wherein locating the workpiece on said chuck lacks involvement of a shoe. ### Claim 6 (depends on 1) The method as set forth in claim 1, wherein said chuck is a magnetic chuck. ### Claim 7 (depends on 1) The method as set forth in claim 1, wherein determining the offset between the axis of rotation of the chuck and the axis of the workpiece comprises determining the offset using a polar coordinate system. ### Claim 8 (depends on 1) The method as set forth in claim 1, wherein determining the offset between the axis of rotation of the chuck and the axis of the workpiece comprises determining the offset via a contact or non-contact sensor. ### Claim 9 (depends on 1) The method as set forth in claim 1, wherein determining the offset between the axis of rotation of the chuck and the axis of the workpiece comprises measuring a diameter of the workpiece. ### Claim 10 (depends on 1) The method as set forth in claim 1, wherein determining the offset between said axis of rotation of said chuck and said axis of the workpiece comprises determining said axis of the bearing workpiece. ### Claim 11 (depends on 10) The method as set forth in claim 10, wherein determining the axis of the workpiece comprises determining the axis of the workpiece via a least squares fit approach. ### Claim 12 (depends on 1) The method as set forth in claim 1, wherein the determined path of engagement of the grinding wheel relative to the workpiece is solely a reciprocation path of engagement of the grinding wheel toward and away from the workpiece. ### Claim 13 (depends on 1) The method as set forth in claim 1, wherein the determined path of engagement of the grinding wheel relative to the workpiece is a horizontal path of engagement of the grinding wheel toward and away from the workpiece. ### Claim 14 (depends on 1) The method as set forth in claim 1, wherein the determined path of engagement of the grinding wheel relative to the workpiece is an engagement of a non-annular portion of the workpiece, and wherein the path of engagement is determined based on a reference location of said non-annular portion relative to the at least one annular portion. ### Claim 15 (depends on 1) The method as set forth in claim 1, further comprising: maintaining a grinding force directed normal to the workpiece less than a threshold force to preclude unwanted movement of the workpiece with respect to said chuck. ### Claim 16 A method of turning a workpiece having at least one annular portion, the method comprising: locating the workpiece on a chuck with an axis of rotation of the chuck positioned off-center relative to an axis of the workpiece at the at least one annular portion; determining an offset between the axis of rotation of the chuck and the axis of the workpiece as a result of the off-center position between the axis of rotation of the chuck and the axis of the workpiece; and determining a path of engagement of a turning tool relative to the workpiece based on the determined offset between the axis of rotation of the chuck and the axis of the workpiece.