Patents by Inventor David G. Parshall

David G. Parshall 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: 4738777
    Abstract: A pressure filter apparatus with media mounting assemblies is provided. The pressure filter tank is generally cylindrical with a cylindrical inner wall having a filter screen therein. A filter media is mounted on the inner wall with seal assemblies above and below the filter screen. Each seal assembly includes a spacer rod and bar continuously welded to the inner wall of the filter and a resilient ring mounted thereon. Each upper and lower edge of the media is sewn to the resilient ring to form a seal therewith.
    Type: Grant
    Filed: June 12, 1986
    Date of Patent: April 19, 1988
    Assignee: AMSTED Industries Incorporated
    Inventor: David G. Parshall
  • Patent number: 4514301
    Abstract: A filter apparatus for removing suspended matter from a suspension including a tank for receiving the contaminated liquid and a filtrate chamber. A perforate wall of the filtrate supports an endless and reusable filter media. The filter media is in the form of a closed loop having a run of the loop located outside and below the tank for the convenience of removing suspended solid collected on the media. The media is displaced along the length of the perforate wall to provide a solids free filter area by a movable conveyor. The conveyor serves to displace the media and hold the marginal edges in sealing engagement with edges of the perforate plate to prevent the contaminated liquid from bypassing the filter area.
    Type: Grant
    Filed: August 24, 1981
    Date of Patent: April 30, 1985
    Assignee: AMSTED Industries Incorporated
    Inventor: David G. Parshall
  • Patent number: 4343701
    Abstract: In a filter device a filter media belt is positioned over a horizontal grid panel. Ends of the belt extend beyond the panel and each is attached to a rotatable forward and rear spool carried outside a cover which encases the grid panel. The cover defines an inner chamber above the grid panel which may be selectively sealed by a closure of doors located at each end of the cover. The cover, doors, and grid panel are sufficiently reinforced to allow the inner chamber to be partially filled with a batch of a liquid-particulate mixture and then pressurized to force the liquid portion through the filter belt and grid panel. During pressurization, longitudinal gasket devices maintain edges of the filter belt sealed against the grid panel. With the liquid portion removed, the particulate in the form of a cake remains on the filter belt. The chamber then is depressurized, the doors opened, and the belt moved forward by rotation of the forward spool.
    Type: Grant
    Filed: April 10, 1981
    Date of Patent: August 10, 1982
    Assignee: AMSTED Industries Incorporated
    Inventor: David G. Parshall
  • Patent number: 4312764
    Abstract: A filtration system includes a deep-bed type filter to receive an inflow of a waste water when the system is in a filtration mode. A distribution plenum within the filter distributes the waste water to an upper and lower portion of the filter bed. As the waste water flows to conduits centrally located within the bed, particulate in the waste water is entrapped by filter media comprising the bed. The waste water is discharged from the system in a clarified condition. Periodically the system is placed in a rejuvenation mode wherein a series of circuits are used to remove the entrapped particulate from the filter bed so that the system may again be returned to its filtration mode to process additional waste water.
    Type: Grant
    Filed: September 11, 1980
    Date of Patent: January 26, 1982
    Assignee: AMSTED Industries Incorporated
    Inventor: David G. Parshall
  • Patent number: 4250036
    Abstract: Filtering devices wherein solid particulate matter is separated by filter media from a liquid flow often contain conveying means for moving the separated solid particulate to an external point for disposition. One such conveying means usable in filtering devices includes spaced endless chain loops wherein each chain comprises alternate center links pivotally joined by pins to alternate sets of spaced side bars. In each center link is an elongated aperture which in a controlled manner holds an extension bar attached to each end of a traversely positioned flight. The spaced chain may be operatively connected to a source of rotary power to periodically advance the conveying means so that the flights may be moved over a section of the filter media to effectively remove separated particulate matter collected thereon.
    Type: Grant
    Filed: August 9, 1979
    Date of Patent: February 10, 1981
    Assignee: AMSTED Industries Incorporated
    Inventor: David G. Parshall