Patent assignee · US · COMPANY

Welker Engineering Company

56Patents
0Active
56Granted
37Portfolio score

Filing activity: Jan 5, 1981 → Mar 30, 2005

Most-cited patents

PatentTitleAreaCited byStatus
US4631967A Automatic insertion device Physics 50 Expired
US4525127A Fluid pump mechanism Physics 33 Expired
US4557151A Sampler incorporating pressure balanced check valve Physics 31 Expired
US7156123B2 Pressure reduction system for quick-connects Emerging Cross-Sectional Technologies 26 Expired
US6338359B1 Dual automatic insertion device Emerging Cross-Sectional Technologies 25 Expired
US4628750A Integrated pump and sample vessel Physics 22 Expired
US5769388A Flow diffuser and valve Emerging Cross-Sectional Technologies 21 Expired
US6964517B2 Temperature probe and insertion device Physics 21 Expired
US4928536A Fluid sample apparatus featuring integral construction with a motor driven sampling system Physics 21 Expired
US5307830A Flow distribution method and apparatus reducing downstream turbulence Emerging Cross-Sectional Technologies 21 Expired
US6085777A Dual cylinder insertion apparatus Emerging Cross-Sectional Technologies 20 Expired
US6827486B2 Temperature probe and insertion device Physics 19 Expired
US4387592A Probe insertion apparatus Physics 17 Expired
US4922764A Constant pressure sample cylinder with spheroid mixer Emerging Cross-Sectional Technologies 17 Expired
US5213586A Vent check valve Emerging Cross-Sectional Technologies 16 Expired
US4850669A Explosion-proof optical fiber connector for a light source Physics 16 Expired
US4459865A Constant pressure cylinder with vortex mixer Emerging Cross-Sectional Technologies 16 Expired
US5924673A Method and apparatus for quieting turbulence in a gas flow line valve Emerging Cross-Sectional Technologies 15 Expired
US4403518A Sampler apparatus Physics 15 Expired
US6250330A Diaphragm regulator with removable diffuser Emerging Cross-Sectional Technologies 15 Expired
US6259523A Optical inspection insertion apparatus for pressurized vessels Mechanical Engineering; Lighting; Heating 15 Expired
US4440032A Sampler incorporating a purge system Physics 14 Expired
US6092519A Heated sample container case and method Mechanical Engineering; Lighting; Heating 14 Expired
US5730416A Method and apparatus for quieting turbulence in a gas flow line valve Emerging Cross-Sectional Technologies 14 Expired
US4463599A Free water volume analyzer Physics 12 Expired

Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.