Hole cutter with chip egress aperture

Abstract

A hole cutter has a substantially cylindrical blade body defining a blade body circumference, a cutting edge formed on one end of the blade body, and an axially-elongated slot formed through the substantially cylindrical blade body. The axially-elongated slot is configured to receive chips flowing from the cutting edge within the interior of the blade body and (i) into the slot, and / or (ii) through the slot, to prevent the collection of such chips within the interior of the blade body and / or at an interface between the blade body and work piece. The axially-elongated slot defines a first end adjacent to the cutting edge, a second end axially spaced further from the cutting edge, and a slot area. The hole cutter further defines a total slot area to blade body circumference ratio within the range of about 0.1 to about 0.3 depending on the size of the hole cutter.

Description

[0001]This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 12 / 687,078 filed Jan. 13, 2010, which is incorporated by reference in its entirety as if fully set forth herein.FIELD OF THE INVENTION[0002]The present invention relates to hole cutters, and more particularly, to hole cutters with apertures formed in the side walls thereof.BACKGROUND INFORMATION[0003]A typical prior art hole cutter includes a cylindrical blade body defining a plurality of saw teeth on the cutting edge of the blade body, and one or more apertures formed through an intermediate portion of the blade body. Typically, smaller diameter hole cutters have fewer apertures formed through the blade bodies, and larger diameter hole cutters have more apertures formed through the blade bodies. The apertures formed through prior art hole cutter blade bodies may define a variety of different configurations to facilitate inserting a tool into the apertures, such as a screw driver, to remo...

AI Technical Summary

Benefits of technology

The present invention is about a hole cutter that is used to cut work pieces. The hole cutter has a cylindrical blade body with an axially-elongated aperture or slot that is designed to prevent the collection of chips within the blade body. The blade body has a diameter of about 13 / 16 inches or less and the slot has a slot area to blade body circumference ratio of at least 0.1. The hole cutter also has a direction of rotation that is the cutting direction of the cutting edge and the first end of the slot is oriented at an acute angle relative to the blade body. The technical effects of this invention include improved chip control, reduced risk of injury, and improved efficiency in hole cutting.

Problems solved by technology

One of the drawbacks encountered with prior art hole cutters is that chips or dust, particularly when cutting wood, collects within the interiors of the hole cutters between the work piece slugs and the caps on the non-working ends of the hole cutters.

The apertures formed in the side walls of the blade bodies are designed to allow the insertion of screw drivers or like tools to remove work piece slugs, but are not configured to allow the chips or dust generated during cutting to flow through the apertures and away from the interiors of the blade bodies.

The collection of chips and dust within the interiors of the blade bodies and / or at the interfaces of the blade bodies and work pieces can significantly reduce the cutting efficiency and overall cutting speed and / or blade life of such hole cutters.

Although many prior art hole cutters include one or more apertures formed through the side walls of the blade bodies, the apertures are not configured to facilitate the flow of chips from the interiors of the blade bodies into and / or through the apertures.