Patents by Inventor Darrell R. Larsen

Darrell R. Larsen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5950944
    Abstract: A novel laminar assembly for use with comminution equipment, such as a liner for protecting the shell of an ore crushing mill or as a wear tip on a blow bar for use in a rock impact crusher. The laminar segment includes a plurality of laminae which are attached to each other with a pair of rods extending through a pair of axial holes positioned in the base of the laminae, thereby forming a segment of virtually any desired length. Conventional mounting bolts may extend through radial holes in the laminae between the axial holes to attach the liner segment to the comminution equipment. The utilization of small laminae enable the laminae to be formed from hardened materials such as heat treated steel or cut from a plate and then heat treated such that the microstructure throughout the laminae may be strictly controlled, thereby providing a laminae with consistent hardness and toughness throughout the laminae.
    Type: Grant
    Filed: August 18, 1998
    Date of Patent: September 14, 1999
    Inventor: Darrell R. Larsen
  • Patent number: 4946110
    Abstract: A novel laminar assembly for use with comminution equipment, such as a liner for protecting the shell of an ore crushing mill or as a wear tip on a blow bar for use in a rock impact crusher. The laminar segment includes a plurality of laminae which are attached to each other with a rod extending through holes positioned in the base of the laminae, thereby forming a segment of virtually any desired length. Mounting bolts are configured in two pieces, with an axial hole extending through the head of the mounting bolt by which they are mounted to the rod and thereby attached to the liner segment. A second piece of the mounting bolt threadably engages the head of the bolt and extends through the mounting surface of the comminution equipment being used. The utilization of small laminae enable the laminae to be cast and heat treated such that the microstructure throughout the laminae may be strictly controlled, thereby providing a laminae with consistent hardness and toughness throughout the laminae.
    Type: Grant
    Filed: January 20, 1989
    Date of Patent: August 7, 1990
    Assignee: American Magotteaux Corporation
    Inventors: Terrance R. Harris, Darrell R. Larsen
  • Patent number: 4319719
    Abstract: The disclosure is directed to an improved liner assembly for an ore grinding mill. The liner assembly is of the segmented type, comprising a first plurality of holder segments which are mounted directly to the shell of the mill, and a second plurality of wear segments which are mounted to the shell in overlying relation to the holder segments, which are thus virtually unexposed to the ore comminution process and wear very slowly. The wear segments are formed with a plurality of downwardly projecting bosses which are received in similarly configured recesses formed within the holder segments. Mounting openings or bores are formed in the wear segments, extending from the top grinding surface to the center of each boss to receive a mounting bolt that extends through both segments and projects externally of the shell to receive a threaded lock nut. These mounting openings are countersunk so that the heads of the mounting bolts securing the wear segments are substantially recessed from the grinding surface.
    Type: Grant
    Filed: January 28, 1980
    Date of Patent: March 16, 1982
    Assignee: Minneapolis Electric Steel Castings Company
    Inventor: Darrell R. Larsen
  • Patent number: 4270705
    Abstract: The disclosure is directed to an improved liner assembly for the drum or shell of an ore grinding machine, comprising a first plurality of liner segments mounted directly to the shell and a second plurality of segments each of which is secured to one of the first segments independently of the shell. In the claimed embodiment, each of the first segments defines a longitudinal, axially extending channel that opens toward the center of the shell and has opposed inner surfaces that converge toward the shell center. The first segments are secured to the shell by nut and bolt assemblies that extend through the segment from the bottom of the channel and through the shell. The second segments are constructed for lengthwise insertion into the channel, and each has converging sides conforming to the channel sides for retention therein, while at the same time protectively overlying the nut and bolt assemblies during the grinding process.
    Type: Grant
    Filed: September 27, 1979
    Date of Patent: June 2, 1981
    Assignee: Minneapolis Electric Steel Castings Company
    Inventor: Darrell R. Larsen
  • Patent number: 4235386
    Abstract: The disclosure is directed to an improved liner assembly for an ore grinding mill. The liner assembly is of the segmented type, comprising a first plurality of segments which are mounted directly to the shell of the mill, and a second plurality of segments each of which is secured to an associated first segment independently of the shell. The first segments are formed from material which is resistant to impact, and the second segments are made from material which is highly resistant to abrasion. As constructed, the second segments can be replaced after a period of wear from inside the mill, avoiding the necessity of replacing the first liner segments which requires working teams both inside and outside the mill. In one embodiment, the second segments are L-shaped and are secured to the first segments by nut and bolt assemblies that are generally aligned with the shell surface to resist shear forces.
    Type: Grant
    Filed: August 11, 1978
    Date of Patent: November 25, 1980
    Assignee: Minneapolis Electric Steel Castings Company
    Inventor: Darrell R. Larsen
  • Patent number: 4165041
    Abstract: A liner assembly for the shell or drum of an ore grinding machine. The liner assembly comprises a plurality of liner segments each of which defines a mounting surface constructed for mounting engagement with the inner shell surface and a grinding surface for comminuting the ore. Each of the segments has longitudinal sides that taper from the grinding surface to the mounting surface. When mounted in side-by-side relation, adjacent liner segments define a pocket between opposed, tapered sides. A wedge-shaped insert is disposed within each pocket and loosely retained therein by the opposed tapered surfaces to reduce the amount of particulate matter entering the pocket and to protect the inner surface of the shell. In the preferred embodiment, the ends of each segment may likewise be tapered toward the mounting surface so that pockets are also defined by the opposed ends of adjacent liner segments, and inserts are also loosely retained in these pockets.
    Type: Grant
    Filed: February 2, 1978
    Date of Patent: August 21, 1979
    Assignee: Minneapolis Electric Steel Castings Company
    Inventor: Darrell R. Larsen
  • Patent number: 4046326
    Abstract: The disclosure is directed to a liner assembly for an autogenous ore grinding machine. The machine includes a large cylindrical drum which is rotated about a horizontal axis to comminute the ore. The liner assembly covers the inner cylindrical surface of the drum and consists of a plurality of longitudinal segments which are removably bolted to the drum. Each segment is made from a material which has good impact resistance and defines an irregular grinding surface to assist in the ore grinding process. An opening is formed through the segment body and extending longitudinally thereof, the opening being defined by walls that converge from the segment mounting surface to its grinding surface. A plurality of inserts, formed from material which is highly resistant to abrasion, are disposed in the opening and cooperate with the converging walls and each other in wedging relation for retainableengagement with the segment body bolted to the drum.
    Type: Grant
    Filed: July 19, 1976
    Date of Patent: September 6, 1977
    Assignee: Minneapolis Electric Steel Castings Company
    Inventor: Darrell R. Larsen
  • Patent number: 4018393
    Abstract: A new procedure and apparatus for securing shell liners in ball and bar mills. The liners are formed with sockets of special shape at predetermined intervals therealong, and are held within the shell of the mill by bolts having heads, received in the sockets, and threaded shanks passing through the liners and the mill shell to nuts on the outside. The sockets and heads are shaped to provided continuous flat contact areas of substantial size regardless of variations in center distances of holes axially along the shell (i.e., the mounting holes are larger than the mounting bolt heads).
    Type: Grant
    Filed: November 6, 1975
    Date of Patent: April 19, 1977
    Assignee: Minneapolis Electric Steel Casting Company
    Inventor: Darrell R. Larsen