US Patents
Du, H., and N.D. Manring. 2002. Apparatus and method for controlling a discharge pressure of a variable displacement hydraulic pump. US Patent Number 6,468,046.
Manring, N.D. 2002. Method and apparatus for controlling straight line travel of a tracked machine. US Patent Number 6,445,990.
Du, H., and N.D. Manring. 2002. Method and apparatus for controlling pump discharge pressure of a variable displacement hydraulic pump. US Patent Number 6,375,433.
Du, H., and N.D. Manring. 2002. Apparatus and method for controlling a discharge pressure of a variable displacement hydraulic pump. US Patent Number 6,374,722.
Manring, N.D., and L. Yu. 2001. Method and system for electrohydraulic valve control. US Patent Number 6,286,412.
Manring, N.D., and J. Ivantysyn. 2001. Extended slipper for hydrostatic pump and motor rotating cylinders. US Patent Number 6,220,144.
Manring, N.D. 1996. Displacement control for a variable-displacement axial-piston pump. US Patent Number 5,564,905.
Manring, N.D. 1996. Pump displacement control for a variable displacement pump. US Patent Number 5,562,424.
Manring, N.D. 1996. Stabilizing device for variable displacement axial piston pumps. US Patent Number 5,568,762.
Childress, D.B., and N.D. Manring. 1996. Pump displacement control for a variable displacement pump. US Patent Number 5,567,123.