Northfield Precision Instrument Corp. introduces its internal grip collet chuck. This collet chuck was custom-designed for a customer to clamp the ID of valve balls. The collet is a dead-length collet with a removable split part stop (part stop is made into two pieces and is hinged) to locate the back of the workpiece and is removed after clamping the workpiece and prior to grinding of the workpiece.
This chuck is used in a valve ball grinder. The ball is approximately 6" in diameter. The customer needed to locate and stop the ball axially on the chuck. So Northfield provided a removable spacer (locator/stop) behind the ball (between the ball and chuck) for axial location. The Locator needed to be removable to allow the grinding wheel (cup) access around the top and bottom of the ball.
Related Glossary Terms
Workholding device that affixes to a mill, lathe or drill-press spindle. It holds a tool or workpiece by one end, allowing it to be rotated. May also be fitted to the machine table to hold a workpiece. Two or more adjustable jaws actually hold the tool or part. May be actuated manually, pneumatically, hydraulically or electrically. See collet.
Flexible-sided device that secures a tool or workpiece. Similar in function to a chuck, but can accommodate only a narrow size range. Typically provides greater gripping force and precision than a chuck. See chuck.
Machining operation in which material is removed from the workpiece by a powered abrasive wheel, stone, belt, paste, sheet, compound, slurry, etc. Takes various forms: surface grinding (creates flat and/or squared surfaces); cylindrical grinding (for external cylindrical and tapered shapes, fillets, undercuts, etc.); centerless grinding; chamfering; thread and form grinding; tool and cutter grinding; offhand grinding; lapping and polishing (grinding with extremely fine grits to create ultrasmooth surfaces); honing; and disc grinding.
- grinding wheel
Wheel formed from abrasive material mixed in a suitable matrix. Takes a variety of shapes but falls into two basic categories: one that cuts on its periphery, as in reciprocating grinding, and one that cuts on its side or face, as in tool and cutter grinding.
- inner diameter ( ID)
inner diameter ( ID)
Dimension that defines the inside diameter of a cavity or hole. See OD, outer diameter.