Hole cutter with extruded cap
AssigneeIrwin Industrial Tool Company
InventorsJoseph Thomas Novak, Robert Richard Zielonka, William B. Korb
Life of this patent
Estimating the term…
Abstract
A hole cutter having an extruded plate cap and methods and apparatuses for making such caps and hole cutters. The plate cap has planar opposing external and internal surfaces with an extruded hub extending axially inwardly from the internal surface. An aperture extends axially through the hub from the external surface. At least a portion of the aperture can be threaded for threaded engagement with a driving arbor. The hub is long enough so that the threaded portion contains at least two full threads. A blade body with a cutting edge is attached to the cap to form a hole cutter.
Claims43
A hole cutter for cutting a work piece, comprising:
- a plate steel cap defining substantially planar opposing external and internal surfaces, a periphery defining a flange, an extruded hub extending axially inwardly from the internal surface and defining an aperture extending through the plate cap and hub, wherein the aperture has a threaded portion extending along at least a portion of its length, and the hub extends axially inwardly from the internal surface a sufficient distance such that the threaded portion defines at least two full threads;
- wherein at least a portion of at least one of the external surface and internal surface is stippled;
- and
- an annular blade body extending axially from the cap, the blade body defining a cutting edge at a distal end from the cap.
A method of manufacturing a hole cutter, comprising:
- forming a cap blank from plate steel defining generally planar external and internal opposing surfaces;
- forming a flange at a periphery of the cap blank;
- forming an aperture though the cap blank extending from the external surface to the internal surface and defining an axis that is substantially perpendicular to the external and internal surfaces;
- extruding the cap blank at the aperture to form a hub extending along the axis inwardly from the external surface and past the internal surface, wherein the aperture extends through the hub;
- and
- threading at least a portion of the aperture to form a threaded portion configured for engagement with an arbor;
- stippling at least a portion of at least one of the external and internal surfaces;
- attaching an axially-extending annular blade body to the cap blank, wherein the blade body defines a cutting edge at a distal end from the cap blank;
- and
- wherein the extruding step comprises extruding the hub sufficiently past the internal surface such that the threaded portion defines at least two full threads.
A hole cutter for cutting a work piece formed by a method comprising the steps of:
- forming a cap blank from plate steel defining generally planar external and internal opposing surfaces;
- forming a flange at a periphery of the cap blank;
- forming an aperture though the cap blank extending from the external surface to the internal surface and defining an axis that is substantially perpendicular to the external and internal surfaces;
- extruding the cap blank at the aperture to form a hub extending along the axis inwardly from the external surface and past the internal surface, wherein the aperture extends through the hub;
- threading at least a portion of the aperture to form a threaded portion configured for engagement with an arbor;
- stippling at least a portion of at least one of the external and internal surfaces;
- attaching an axially-extending annular blade body to the cap blank, wherein the blade body defines a cutting edge at a distal end from the cap blank;
- wherein the extruding step comprises extruding the hub sufficiently past the internal surface such that the threaded portion defines at least two full threads.
Dependencies are inferred from the claim text.