Having Central Lead-screw Patents (Class 408/214)
  • Patent number: 5244319
    Abstract: A boring bit for boring holes in one or more workpieces such as wood and the like. An axially elongated shank portion of the boring bit has a tool engaging portion at one end and a head portion on a second end. A central axis longitudinally extends through the shank portion. The head portion includes a helically disposed surface on the end of the head portion which is frusto-conically sloped inwardly towards the central axis and generally towards the tool engaging portion. The helical surface has leading and following termini of which the leading terminus is advanced beyond the following terminus more than one-half of a helical revolution around the central axis along the shank portion. A cutting face, which is a planar surface, is perpendicularly spaced away from and extends parallel to the central axis. The cutting face intersects the leading terminus for scribing the bore circumference and scraping material from a workpiece when the boring bit is employed to form a bore in such a workpiece.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: September 14, 1993
    Assignee: Greenlee Textron Inc.
    Inventor: Paul Cochran
  • Patent number: 5193951
    Abstract: A drill bit includes an elongated shaft with a threaded male end and a cutting head with an axial through-bore having female threads to receive the male end of said shaft in threaded engagement, and there is a bearing surface area between the shaft and the cutting head above the threaded portion which provides for proper alignment and reduced stresses.
    Type: Grant
    Filed: May 17, 1991
    Date of Patent: March 16, 1993
    Assignee: Vermont American Corporation
    Inventor: Thomas O. Schimke
  • Patent number: 4645389
    Abstract: A multiple-toothed drill bit having at least three teeth is provided with front end cutting edges having respective outer and inner cutting edge sections oriented angularly to each other and meeting at respective frontwardmost cutting points located in a common plane, and with an axial centering spur having laterally outwardly and rearwardly inclined center cutting edges merging with the inner front end cutting edge sections via respective frontwardly concave cutting edge sections.
    Type: Grant
    Filed: December 10, 1984
    Date of Patent: February 24, 1987
    Assignee: Hartmetallwerkzeugfabrik Andreas Maier GmbH & Co.
    Inventor: Andreas Maier
  • Patent number: 4625593
    Abstract: A wood drill and method for its manufacture are disclosed. A drill body has an axial web with spiral lands and a holding shank. The top of the web has an axial hole receiving a projection from a separate lead screw and the top of each spiral land has a recess receiving a carbide insert for cutting. The lead screw and carbide cutting inserts are fixed to the drill body and the inserts and lands are ground to provide the proper hole sizing tips and cutting surfaces. The elements are fixed so that they can be removed for repair; they are shown as being brazed. The spiral lands can be contoured to have a spiral groove located in one or more spiral surfaces inwardly from the outer end.
    Type: Grant
    Filed: August 7, 1984
    Date of Patent: December 2, 1986
    Inventor: Norman H. Schmotzer
  • Patent number: 4536107
    Abstract: A self-feeding, self-aligning drill bit includes a working end with a cylindrical portion having a desired cutting diameter and a conical threaded portion extending therefrom terminating in a threaded tip. The diameter of the threaded portion increases from the tip toward the cylindrical portion such that it approaches the diameter of the cylindrical portion at their juncture. One or more flutes extend longitudinally through both the cylindrical portion and the threaded portion to form one or more cutting edges extending at an angle relative to the axis of the drill bit. The threaded portion may include one or more peripheral grooves staggered along the length of the threaded portion to provide additional cutting edges to reduce cutting torque. The threaded portion not only pulls the bit into the workpart but also the cutting edges thereof function to cut a preliminary hole and also cut apart the workpart debris to significantly reduce chip size.
    Type: Grant
    Filed: August 29, 1983
    Date of Patent: August 20, 1985
    Assignee: Ex-Cell-O Corporation
    Inventors: Julius W. Sandy, William D. Riebock, Billy J. Bauscher
  • Patent number: 4330229
    Abstract: A drill bit having a generally cylindrical body with a working end and flutes extending along the body. The working end is formed with a central work-engaging point and a pair of slitting spurs spaced outwardly from the point adjacent edge margins of the body. Convexly contoured portions interconnect the point and spurs to permit sharpening with a round file.
    Type: Grant
    Filed: December 4, 1980
    Date of Patent: May 18, 1982
    Assignee: Omark Industries, Inc.
    Inventor: Frederic G. Croydon
  • Patent number: 4244667
    Abstract: A boring tool of the self-feeding type is disclosed which includes a plurality of cutting members secured to a body and a self-feeding member operative to draw the boring tool into the workpiece. The cutting elements are positioned on the body in such a manner as to provide a depth of cut correlated to the rate of advancement effected by the feed member thereby insuring smooth even efficient cutting action of the boring tool. Additionally, the body is provided with a work engaging surface portion operative to further insure controlled even advancement of the boring tool through the workpiece. A retaining member is also provided in the body member which is operative to retain a one piece feed membershank within the body and to maintain the self-feeding member in close proximity to an adjacent cutting member so as to prevent wrapping of wood fibers or the like about the self-feeding member.
    Type: Grant
    Filed: September 28, 1979
    Date of Patent: January 13, 1981
    Assignee: Black & Decker Inc.
    Inventor: Russell M. Timmons
  • Patent number: 4239427
    Abstract: A boring tool is disclosed for machining holes in various materials which comprises a one piece body have a plurality of cutting members secured thereto in circumferentially spaced relationship. The cutting members are designed so as to enable them to be interchanged between a variety of different diameter bodies, the number of such cutting members increasing with greater diameter bodies. The body is provided with mounting surfaces positioned in such a manner so as to automatically accurately locate the cutting elements with respect to the body and to substantially eliminate any shear loading on the fastening elements securing the cutting members thereto thereby enabling use of only a single fastener element to secure each of the cutting members to the body. The cutting members are preferably circumferentially and radially spaced relative to each other so as to substantially balance the cutting loads thereby assuring positive accurate hole formation.
    Type: Grant
    Filed: September 28, 1979
    Date of Patent: December 16, 1980
    Assignee: Black & Decker Inc.
    Inventor: Richard E. Walton, II
  • Patent number: 4090807
    Abstract: The invention relates to a bit for boring a hole in wood or the like, the bit having a surrounding skirt to give the bit axial stability during a boring operation, and, a leading spur to produce a circumambient groove prior to and deeper than the cutting blades to prevent material being cut from the bore, from splintering beyond the perimeter of the bore and thus produce a smooth wall surface.
    Type: Grant
    Filed: September 20, 1976
    Date of Patent: May 23, 1978
    Inventor: Arthur A. Stewart
  • Patent number: 3945753
    Abstract: Drill bit construction having a removable lead screw and a drill body with a work face comprised of two planar surfaces which geometrically intersect on a diameter line such that the angle between the two surfaces is approximately 170.degree.. A cut-away segment is formed on each side of the body with each of the segments having a cutting edge in the form of a detachable blade which is also provided with a cutting spur on the outer end. The body itself is detachably removable from the drill shaft or shank. The body is also provided with a removable lead screw or guide point.
    Type: Grant
    Filed: July 29, 1974
    Date of Patent: March 23, 1976
    Inventors: John E. Byers, Gary L. Byers
  • Patent number: RE28900
    Abstract: Drill bit construction having a removable lead screw and a body which has a conically shaped work facing surface. With generally triangularly shaped cut-away segments. Each of the segments has a cutting edge either in the form of a detachable blade or integrally formed into the body. The body itself is also detachably removable from the drill shaft or shank. In smaller diameter embodiments a spiral member recedes from the shaft adjacent the head for removing shaving as the bit proceeds through the wood.
    Type: Grant
    Filed: August 26, 1974
    Date of Patent: July 13, 1976
    Inventors: John E. Byers, Wells H. Claussen