Michael A. A'Hearn has been granted 8 US patents while listed as an inventor at Caterpillar . The first was granted in 1998 and the most recent in October 2005. Michael A. A'Hearn ranks #600,572 of 4,157,543 US inventors in our database (top 14.4%). Patent records list Michael A. A'Hearn in Shorewood, IL, US.
Patents per Year Patents granted per year, 1998 to 2005 Bar chart with a peak of 3 patents in 2001. peak 3 1998: 1 patents 1998 2000: 1 patents 2000 2001: 3 patents 2001 2002: 1 patents 2002 2004: 1 patents 2004 2005: 1 patents 2005
Issued Patents All Time
Profile Widget
Showing 1–8 of 8 patents
Patent # Title Co-Inventors Date Approx Value ⓘ
6955115 Hydraulic circuit having pressure equalization during regeneration Thomas J. Hajek, Sr. , Larry W. Lorimor , Daniel T. Mather , Srikrishnan T. Tolappa 2005-10-18
$83,106,000
6761027 Pressure-compensated hydraulic circuit with regeneration Daniel J. Mather , Srikrishnan T. Tolappa 2004-07-13
$29,476,000
6357230 Hydraulic ride control system David J. Carlson , Thomas J. Hajek, Jr. , Andy Hatcher , Michael Hudson , Patrick Quinn +1 more 2002-03-19
$15,159,000
6321534 Ride control Thomas J. Hajek, Jr. , Michael Hudson , Lawrence F. Schexnayder , Srikrishnan T. Tolappa 2001-11-27
$12,362,000
6205781 Fluid control system including a work element and a valve arrangement for selectively supplying pressurized fluid thereto from two pressurized fluid sources — 2001-03-27
$12,204,000
6173639 Fluid control system having float control Thomas J. Hajek, Jr. , Srikrishnan T. Tolappa 2001-01-16
$15,427,000
6161467 Fluid control system with regeneration Thomas J. Hajek, Jr. , Tony L. Marcott , Srikrishnan T. Tolappa 2000-12-19
$18,572,000
5826487 Pressure control for a pair of parallel hydraulic circuits — 1998-10-27
$12,942,000
