Patents by Inventor David C. Graves

David C. Graves 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: 6279845
    Abstract: A coupling for driving a magnetic tape reel uses the interface between a flat surface on the coupling and datum pads on the reel to locate the reel. The coupling includes a drive ring with ring teeth located around a drive shaft. The ring teeth engage mating teeth on the tape reel. The coupling also includes a datum ring having an annular surface located about the drive shaft. The annular surface contacts datum pads on the tape reel to axially position the tape reel relative to the drive shaft.
    Type: Grant
    Filed: September 12, 2000
    Date of Patent: August 28, 2001
    Assignee: Storage Technology Corporation
    Inventors: Wayne R. Hemzacek, David T. Hoge, Joseph P. Falace, David C. Graves, Clark Janssen, Michael W. Johnson, Steven A. Bendson
  • Patent number: 6194625
    Abstract: Disclosed are various embodiments for alkylating olefins and isoparaffins in the presence of an acid to reduce and/or control acid consumption or maximize and/or control the octane number of the produced alkylate product. One embodiment includes alkylation by controlling the C3/iso-C5 olefin ratio to reduce acid consumption. Another embodiment includes alkylation of C3 and C5 olefins in separate alkylation zones to maximize alkylate octane number. Even another embodiment includes propylene alkylation followed by C4 and/or C5 olefin alkylation, with the spent propylene acid used in the C4 and/or C5 olefin alkylation. Still another embodiment includes alkylation of C3, C4 and C5 olefins in separate alkylation zones, with the spent propylene acid used in the C4 alkylation, and the spent butylene acid used in the C5 alkylation. Yet another embodiment includes alkylation by controlling the C3/C4 olefin ratio to maximize the octane number of the produced alkylate.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: February 27, 2001
    Assignee: Stratco, Inc.
    Inventors: David C. Graves, Ken Edward Kranz, James Kevin Millard, Lyle Frederick Albright
  • Patent number: 5432652
    Abstract: A magnetic tape has three evenly spaced-apart longitudinally-extending servo track areas. Four equal-sized longitudinally-extending data track areas are disposed between said servo track areas and between longitudinal edges of the tape and one of said longitudinally-extending data track areas. For track following, all servo track areas are simultaneously sensed for producing one head positioning signal. Data tracks are arranged into four groups of tracks, one-half of the data tracks in each group are concurrently accessed. The data tracks on the tape are arranged in clusters. Each cluster has one track from each of the groups of tracks. Two laterally-adjacent track clusters constitute four data track wraps for serpentine scanning of data tracks. The concurrent track accessing respectively occurs in first and second halves of a data track wrap (there is a number of wraps equal to one half the number of track clusters). Each servo area indicates two lateral positions of the tape to the head.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: July 11, 1995
    Assignee: International Business Machines Corporation
    Inventors: Wayne T. Comeaux, David C. Graves, Douglas W. Johnson
  • Patent number: 5425070
    Abstract: Apparatus for engaging and aligning lower ends of rodlets, or pins, of a nuclear fuel assembly insert. The apparatus facilitates positioning the insert within guide tubes of a nuclear fuel assembly. The nuclear fuel assembly insert rodlet alignment apparatus includes a mounting rack for attachment to a reactor or spent fuel pool edge, a first fixed plate attached to the mounting rack's lower end, and a second sliding plate attached to the first fixed plate. The first and second plates are respectively provided with first and second comb structures each comprised of elongated, linear, pointed teeth arranged in a spaced manner along an edge of a generally flat plate. The lower end of a crank, or rotating shaft, is coupled to the sliding plate by means of suitable linkage permitting the sliding plate to be moved on the fixed plate between a first position wherein the two comb structures are non-overlapping and a second position wherein the two comb structures overlap.
    Type: Grant
    Filed: July 22, 1994
    Date of Patent: June 13, 1995
    Assignee: Commonwealth Edison Company
    Inventors: James S. Gosnell, David C. Graves
  • Patent number: 5394280
    Abstract: A magnetic tape drive simultaneously senses on a magnetic tape three evenly spaced-apart servo track areas for servoing a multi-track magnetic head to follow a concurrent set of data tracks on the magnetic tape. The data tracks are arranged into a plurality of track groups. Each track group has a first and second subgroup of data tracks. The first subgroup of tracks are scanned in a first relative motion of the magnetic tape and magnetic head as a forward direction (tape is being spooled from a supply tape reel). The second subgroup of tracks are scanned in a second relative motion of the magnetic tape and magnetic head that is opposite in direction to the first relative direction and is a forward direction of scanning. While writing data in any one of the plural track groups, a servo dropout affecting most of the servo track areas is detected and indicated as a servo error. Writing is aborted. The relative position of the magnetic tape and head is detected at both longitudinal ends of the servo dropout.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: February 28, 1995
    Assignee: International Business Machines Corporation
    Inventors: Alex Chliwnyj, David C. Graves, Scott M. Fry, Pamela R. Nylander-Hill, Habib M. Torab, Will A. Wright
  • Patent number: 5265082
    Abstract: A system uses prevent and detect mechanisms to enable rewritable data storage media to be operated as a written-once-only media. A physical indication of the media casing serves as an indicator of the write-once-only status of the media. A watermark is magnetically recorded on the media at the factory with a portion of the mark detectable by the system and a portion only detectable by returning to an inspection station for verification. This protects against a complete erasure of all data from the media. A segment write status indication serves to indicate the write-once-only status of each segment of the written data. A portion of the written region, such as the preamble or control field of each segment, contains a status mark written randomly within the area as a status indication that the data was written once or multiple times within that segment.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: November 23, 1993
    Assignee: International Business Machines Corporation
    Inventors: John J. Gniewek, David C. Graves
  • Patent number: 4580176
    Abstract: An adaptive equalization circuit for magnetic recording channels which derives an error signal to change the equalizer compensation value from the timing of random signal data and provides continuous feedback compensation.
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: April 1, 1986
    Assignee: International Business Machines Corporation
    Inventors: David C. Graves, Richard C. Schneider, Volker Zimmermann