Patent ID: 6939092
Filing Date: 2005-09-06
Classification: B23B,Y10T

Abstract:
1. A sheet metal hole cutter, comprising: a cap plate defining a substantially circular peripheral groove and an annular shelf extending radially outwardly from the peripheral groove; and an elongated band forming an approximately circular shape with opposite ends of the band contacting each other, wherein the band includes: a base edge received within the circular peripheral groove in an abutting relationship with an inner edge of the groove; a weld region formed between the band and cap plate and fixedly securing the base edge of the band to the cap plate, wherein the annular shelf of the cap plate extends radially outwardly of the base edge of the band and defines a radial depth between the outer edge of the shelf and the base edge of the band equal to at least approximately 1/16 of an inch; and a cutting edge located on a side of the band opposite the base edge and defining a plurality of teeth, wherein each of a plurality of the teeth includes: a carbide tip; a rake face adjacent to the tip; a curvilinear base surface located on an opposite side of the rake face relative to the tip; at least one relief surface located on an opposite side of the tip relative to the rake face; an outer edge; an inner edge; a cutting surface extending between the outer edge and the inner edge, wherein the cutting surface is oriented at an acute angle relative to a plane of the cap plate such that the outer edge of the respective tooth is spaced further away from the cap plate than the inner edge; an outer side defining an outer work-engaging surface contiguous to the outer edge; and an inner side defining an inner work-engaging surface contiguous to the inner edge; wherein the cutting edge further includes a plurality of inner clearance surfaces spaced radially outwardly relative to respective inner work-engaging surfaces for forming inner clearances between the inner surfaces of the teeth and a work piece; and wherein the band defines an axial depth between the outermost tooth tip and an inner surface of the cap plate of less than approximately ¾ of an inch; and the band defines an outer diameter within the range of approximately 9/16 of an inch through approximately 6 inches.