Patents by Inventor Donald F. Graveman

Donald F. Graveman 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: 5628467
    Abstract: A hammermill-type shredding apparatus having a rotor assembly disposed in a housing, the rotor assembly including hammer elements of longer and shorter lengths mounted in an intersticed or alternating manner thereon, a grate having thicker and thinner portions in like alternating manner so as to accept longer length hammers adjacent the thinner portions of the grate and between the thicker portions of the grate, the housing further provided with a comb assembly having finger portions extending into the circle defined by the hammers when in operation, and further extending between the hammer elements so as to remove and prevent any undesirable materials accumulations.
    Type: Grant
    Filed: July 19, 1994
    Date of Patent: May 13, 1997
    Assignee: Magnatech Engineering, Inc.
    Inventor: Donald F. Graveman
  • Patent number: 5562257
    Abstract: A hammermill includes a pair of rotors to each of which are attached a plurality of relatively long and relatively short hammers. In one embodiment each long hammer on one rotor is arrayed opposite a short hammer on the other rotor such that, as the rotors rotate, a circular path described by an end of each long hammer is in close proximity to a circular path described by an end of a corresponding short hammer on the other rotor. The long hammers are interleaved and a plurality of impact plates are shaped and positioned in close proximity to the hammer circular tip paths so that materials being reduced by the hammermill impact the impact plates until the materials are reduced to a desired size. The inventive hammermill is particularly effective in reducing tough and pliable materials such as automobile tires as well as light materials such as paper and aluminum cans.
    Type: Grant
    Filed: January 26, 1996
    Date of Patent: October 8, 1996
    Assignee: Magnatech Engineering Incorporated
    Inventors: Donald F. Graveman, William F. Graveman
  • Patent number: 4720051
    Abstract: A shredding machine has a housing provided with an upwardly presented inlet, and in addition a rotor which revolves within the housing over an arcuate grate which is also in the housing. The rotor includes hammers, the tips of which describe a hammer circle that passes close to the arcuate grate. The hammers generate considerable windage as the rotor revolves, and to prevent this windage from being directed upwardly out of the inlet and thereby interfering with the flow of lightweight feed materials into and through the inlet, a deflector is mounted in the housing over the hammer circle, generally along that portion of the hammer circle that leads up to the top of the circle. The deflector directs the windage generally laterally across the inlet instead of upwardly out of it, and indeed causes much of the air to be drawn around and to a large measure discharged through the grate. As a result even light weight feed materials fall easily into the hammers.
    Type: Grant
    Filed: December 16, 1985
    Date of Patent: January 19, 1988
    Assignee: American Pulverizer Company
    Inventors: Donald F. Graveman, Sven B. Strom
  • Patent number: 4205795
    Abstract: At a coal handling facility a reducing machine is mounted on a common carriage along with a by-pass chute, and this carriage is capable of moving either the reducing machine or the by-pass chute into a position directly beneath a receiving hopper. When the by-pass chute is directly below the hopper, coal passes through that chute without interference. However, during winter months when moisture has a tendency to freeze coal together into large lumps, the carriage is moved to bring the reducing machine directly beneath the receiving hopper. The reducing machine has a rotor which engages the large lumps of frozen coal and reduces them to a size more suitable for conveyors and other coal handling equipment. Thus, the coal passes through the reducing machine only when it is necessary to break the frozen coal into smaller lumps, and this in turn prolongs the life of the reducing machine.
    Type: Grant
    Filed: October 26, 1978
    Date of Patent: June 3, 1980
    Assignee: American Pulverizer Company
    Inventor: Donald F. Graveman
  • Patent number: 4149677
    Abstract: A ring hammer for a reducing machine includes an annular body and tooth projected radially from the annular body and arranged in two rows, with the teeth of the one row being spaced axially from the teeth of the other row and further being offset circumferentially from the teeth of the other row. A reinforcing ring extends around the annular body in the space between the two rows of teeth and is formed integral with the annular body and the teeth of the two rows. The reinforcing ring tapers downwardly to the side faces of the annular body in the spaces between successive teeth of each row so that the teeth possess greater depth at their outside faces than at their inside faces. The reinforcing ring strengthens the ring hammer and renders the teeth less susceptible to breakage.
    Type: Grant
    Filed: November 14, 1977
    Date of Patent: April 17, 1979
    Assignee: American Pulverizer Company
    Inventors: Donald F. Graveman, Donald G. Miller
  • Patent number: 4009836
    Abstract: A material reducing machine has a housing and a reversible rotor which revolves in the housing. On each side of the rotor the housing carries wear plates which pivot such that their lower ends will move inwardly, thus enabling the wear plate to serve as a deflecting vane for diverging windage away from the feed opening of the housing. Only the vane on the ascending side of the rotor is opened, the other being closed to serve as a wear and breaking surface against which the material is hurled. The grate beneath the rotor is in two sections with the juncture between the sections being directly below the axis of the rotor. At this juncture, the sections are provided with intermeshing teeth to prevent a gap from forming in the grate. The grate sections are supported on cages which pivot at their upper ends and are moved upwardly and downwardly at their lower ends by cams to adjust the spacing between the grate and rotor.
    Type: Grant
    Filed: June 30, 1975
    Date of Patent: March 1, 1977
    Assignee: American Pulverizer Company
    Inventors: Sven B. Strom, Donald F. Graveman
  • Patent number: 3934826
    Abstract: The breaker plate of a coal crusher has holes therein so that coal small enough to pass through those holes does so without being acted upon by the rotor. This increases the capacity of the crusher, reduces fines, and conserves power. The plate is oriented such that windage generated by the rotor urges the smaller pieces of coal through the holes.
    Type: Grant
    Filed: June 5, 1974
    Date of Patent: January 27, 1976
    Assignee: American Pulverizer Company
    Inventor: Donald F. Graveman