DH

David G. Holloway

PC Parker & Harper Companies: 5 patents #1 of 3Top 35%
PC Parker And Harper Manufacturing Company: 4 patents #2 of 3Top 70%
📍 Concord, NH: #23 of 196 inventorsTop 15%
🗺 New Hampshire: #1,680 of 12,181 inventorsTop 15%
Overall (All Time): #586,538 of 4,157,543Top 15%
9
Patents All Time

Issued Patents All Time

Showing 1–9 of 9 patents

Patent #TitleCo-InventorsDate
6708489 Pneumatic actuator Roger G. Massey 2004-03-23
5819775 Low flow rate valve 1998-10-13
5772177 Valve latching device for single handed operation Kenneth Madden, Roger G. Massey 1998-06-30
5647389 Indexable latching handle assembly for quarter-turn rotary valves 1997-07-15
5460351 Valve stem locking assembly 1995-10-24
4909275 Latching handle Roger G. Massey, Kenneth Walton 1990-03-20
4727899 Pilot valve assembly Roger G. Massey 1988-03-01
4559966 Valve handle with selectable stops Roger G. Massey 1985-12-24
4326627 Limit switch for rotary control device Roger G. Massey 1982-04-27