Patents by Inventor David M. Pittman

David M. Pittman 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: 8851111
    Abstract: The controller of the plural component proportioner (10) dispenses both components (or all three if a three component material) simultaneously (at least initially) and maintains ratio at the end of each predetermined volume of material by determining which component pump (12) has reached the desired amount of travel (given the resolution available) and using a valve (16) to shut off output of that pump until the other side has caught up. At pump changeover, the output valve for that pump (12) is shut off and the air motor (12a) allowed to run until travel stops to account for cavitation, air entrainment, compressibility, or poor inlet check performance.
    Type: Grant
    Filed: November 27, 2002
    Date of Patent: October 7, 2014
    Assignee: Graco Inc.
    Inventors: David M. Pittman, Vu K. Nguyen
  • Patent number: 8568112
    Abstract: An air valving system for a reciprocating piston pump (5) which uses piston (10) actuated poppet assemblies (40) to control the main air valve (16) shift. The valve exhaust is vented (50) directly to atmosphere rather than through the main exhaust to ensure reliability. A ramped detent (32) prevents the air valve (16) from centering.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: October 29, 2013
    Assignee: Graco Minnesota Inc.
    Inventors: Mark L. Bauck, John F. Isais, Jr., Mark T. Weinberger, David M. Pittman, Michael E. Bloom
  • Publication number: 20080213105
    Abstract: An air valving system for a reciprocating piston pump (5) which uses piston (10) actuated poppet assemblies (40) to control the main air valve (16) shift. The valve exhaust is vented (50) directly to atmosphere rather than through the main exhaust to ensure reliability. A ramped detent (32) prevents the air valve (16) from centering.
    Type: Application
    Filed: July 26, 2006
    Publication date: September 4, 2008
    Inventors: Mark L. Bauck, John F. Isais, Mark T. Weinberger, David M. Pittman, Michael E. Bloom
  • Patent number: 6896152
    Abstract: An electronic apparatus is provided for dispensing plural component materials having first and second (and optionally third) components and a desired ratio between the components. The apparatus has first and second reciprocating pumps (4), each of the pumps (4) being connected to a source of one of said components, first and second reciprocating drivers (5), each driver (5) being connected to drive one of the pumps and forming a driver-pump set, a position sensor (6) attached to each driver-pump set, each position sensor (6) outputting increments of resolution corresponding to a fixed volume being pumped by the driver-pump set to which it is connected, and a controller attached to the drivers and the position sensors to alternately move one of the driver-pump sets one said increment and the other of the driver-pump sets the product of one increment and the ratio.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: May 24, 2005
    Assignee: Graco Minnesota Inc.
    Inventors: David M. Pittman, Adam R. Friedrich
  • Publication number: 20030015547
    Abstract: An electronic apparatus is provided for dispensing plural component materials having first and second (and optionally third) components and a desired ratio between the components. The apparatus has first and second reciprocating pumps (4), each of the pumps (4) being connected to a source of one of said components, first and second reciprocating drivers (5), each driver (5) being connected to drive one of the pumps and forming a driver-pump set, a position sensor (6) attached to each driver-pump set, each position sensor (6) outputting increments of resolution corresponding to a fixed volume being pumped by the driver-pump set to which it is connected, and a controller attached to the drivers and the position sensors to alternately move one of the driver-pump sets one said increment and the other of the driver-pump sets the product of one increment and the ratio.
    Type: Application
    Filed: August 27, 2002
    Publication date: January 23, 2003
    Inventors: David M. Pittman, Adam R. Friedrich
  • Patent number: 6168308
    Abstract: A mechanical proportioner is provided with two pump lowers which are connected together by a yolk underneath an air-operated reciprocating piston pump. The pumps are staggered axially so as to enable overlapping of certain portions thereof thereby enabling the center-to-center distance to be minimized. The mix manifold is constructed in a concentric fashion such that mixed material does not come into contact with the mix manifold until it enters the static mixer at the exit of the manifold which is an easily disposable and replaceable part. The purge solvent valves on the mix manifold are each provided with an extension of their respective handles. If either purge valve is in its open position, a separate interlock handle operating the A and B side valves at the manifold inlet is prevented from opening. Similarly, if the interlock handle operating the A and B side valves is open, the purge valves cannot be opened.
    Type: Grant
    Filed: February 15, 1999
    Date of Patent: January 2, 2001
    Assignee: Graco Minnesota Inc.
    Inventors: David M. Pittman, Kenneth E. Lehrke, John F. Isais, Vicky J. Peterson, Adam R. Friedrich