Patents by Inventor Karl H. Hellman
Karl H. Hellman 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: 6910459Abstract: An internal combustion engine is adapted for operation with homogeneous combustion and compression ignition. The engine includes plural cylinders with the piston in each cylinder defining the main combustion chamber and connected to a crankshaft for reciprocating motion rotatably driving the crankshaft. An auxiliary combustion chamber and an inlet passage are formed in the engine head for each of the cylinders with a control valve for controlling communication between the main combustion chamber and the auxiliary combustion chamber and an inlet valve for controlling communication between the main combustion chamber and the inlet passage. The inlet valve is driven with rotation of the crankshaft, while the drive for the combustion control valve is independent of angular position of the crankshaft and has its own controller for timing its opening and closing to provide controlled homogeneous combustion.Type: GrantFiled: May 30, 2003Date of Patent: June 28, 2005Assignee: The United States of America as represented by the Administration of the U.S. Environmental Protection AgencyInventors: Ruonan Sun, Karl H. Hellman, Charles L. Gray
-
Publication number: 20040237928Abstract: An internal combustion engine is adapted for operation with homogeneous combustion and compression ignition. The engine includes plural cylinders with the piston in each cylinder defining the main combustion chamber and connected to a crankshaft for reciprocating motion rotatably driving the crankshaft. An auxiliary combustion chamber and an inlet passage are formed in the engine head for each of the cylinders with a control valve for controlling communication between the main combustion chamber and the auxiliary combustion chamber and an inlet valve for controlling communication between the main combustion chamber and the inlet passage. The inlet valve is driven with rotation of the crankshaft, while the drive for the combustion control valve is independent of angular position of the crankshaft and has its own controller for timing its opening and closing to provide controlled homogeneous combustion.Type: ApplicationFiled: May 30, 2003Publication date: December 2, 2004Inventors: Ruonan Sun, Karl H. Hellman, Charles L. Gray
-
Patent number: 6386154Abstract: An exhaust gas recirculation system for an internal combustion engine includes an exhaust manifold and at least one exhaust flow control valve located between the engine and the exhaust manifold. The exhaust flow control valve diverts a portion of the exhaust gas from each cycle of one cylinder and feeds that diverted portion to another of the cylinders through an exhaust gas recirculation passage, bypassing the exhaust manifold, whereby an exhaust stroke of a piston within the one cylinder serves to pump exhaust gas through the exhaust flow control valve in another cylinder.Type: GrantFiled: June 12, 2000Date of Patent: May 14, 2002Assignee: The United States of America as represented by the Administrator of the Environmental Protection AgencyInventors: Karl H. Hellman, Charles L. Gray, Jr.
-
Patent number: 5609131Abstract: The invention is a combustion method for operation of a multiple cylinder internal combustion engine in a cycle including intake, compression, expansion and exhaust strokes. A first amount of fuel is introduced into each of the cylinders with introduction initiated earlier than 45.degree. before top dead center of a combustion stroke. An amount of air significantly in excess of that providing a stoichiometric amount of oxygen, typically 2-3 times stoichiometry, is also introduced into each of the cylinders to produce a first mixture upon introduction of the fuel, which mixture is ignited to produce a first combustion event. Subsequent to substantial completion of the first combustion event but prior to top dead center in the same compression stroke (or shortly after top dead center in the expansion stroke), a second amount of fuel is introduced into each of the cylinders without introduction of additional air.Type: GrantFiled: October 11, 1995Date of Patent: March 11, 1997Assignee: The United States of America as represented by the Administrator of the U.S. Environmental Protection AgencyInventors: Charles L. Gray, Jr., Karl H. Hellman
-
Patent number: 5579640Abstract: A hydropneumatic powertrain includes a fluidic driver connected in parallel with first and second liquid tanks connected, respectively, with first and second gas vessels. The gas within each gas vessel is in fluid communication with the liquid within the corresponding liquid vessel. A prime mover drives a pump to pump liquid alternately into one of the two liquid tanks connected in parallel with the pump. Switch valving directs the discharge of the pump to either the first liquid tank or the second liquid tank, while the liquid tank not receiving liquid from the pump discharge is discharging its liquid, driven by expansion of gas within the corresponding gas vessel, to drive the fluidic driver which, in turn, drives the drive wheels of the vehicle. Each gas tank is equipped with a heater and a cooler whereby the gas vessel, in the compression portion of the cycle, is cooled while the other gas vessel is heated for expansion of the gas contained therein.Type: GrantFiled: April 27, 1995Date of Patent: December 3, 1996Assignee: The United States of America as represented by the Administrator of the Environmental Protection AgencyInventors: Charles L. Gray, Jr., Karl H. Hellman
-
Patent number: 5549087Abstract: A method of operation of an internal combustion engine to minimize NOx emission in exhaust gas involves detection of load on the vehicle engine as either a low load or a high load. While a low load is detected unthrottled air and a quantity of fuel providing for lean combustion are mixed with injection of fuel adjacent top dead center in the compression stroke. While a high load condition is detected, throttled air and a quantity of fuel governed by sensed oxygen content of the exhaust gas are mixed in an approximate stoichiometric ratio with injection of the fuel much earlier than injection at low load, preferably during the intake stroke.Type: GrantFiled: October 11, 1995Date of Patent: August 27, 1996Assignee: The United States of America as represented by the Administrator of the U.S. Environmental Protection AgencyInventors: Charles L. Gray, Jr., Karl H. Hellman
-
Patent number: 5505527Abstract: A vehicular powertrain with regenerative braking includes a plurality of wheels and a brake pedal which, upon engagement, is activated first into a first zone of operation and then into a second zone of operation. A braking detector detects either a released state or an engaged state for the brake pedal and, if in the engaged state, detects if the pedal is in the first or the second zone of operation. Friction brakes brake a pair of the wheels, responsive to detection of the brake pedal within the second zone of operation. The hydraulic portion of the drivetrain includes an accumulator for storing hydraulic fluid under pressure and a reservoir for storing the hydraulic fluid at a lower pressure. A pump/motor is located in the high pressure line for operation as a motor to drive the drive wheels in a drive mode and for operation as a pump driven by the drive wheels in a braking mode.Type: GrantFiled: March 16, 1995Date of Patent: April 9, 1996Assignee: The United States of America as represented by the Administrator, U.S. Environmental Protection AgencyInventors: Charles L. Gray, Jr., Karl H. Hellman, Ronald M. Schaefer
-
Patent number: 5495912Abstract: Engine output speed is controlled for optimum efficiency by adjustment of input speed of a continuously variable transmission (CVT). Where power in excess of that provided by the engine is required, additional power is input to the drivetrain from a fluidic motor driven by fluid pressure stored in an accumulator. In driving conditions where the engine, operating at optimum efficiency, produces power in excess of that demanded by of the vehicle, the fluidic motor is reversed for operation as a pump and excess engine power is utilized to drive the pump and store energy in the accumulator in the form of fluid pressure. A CPU determines power output required of the engine as a sum of that indicated by a sensor which senses power demanded of the vehicle by a driver and an increment of power required to maintain the pressure of the accumulator above a threshold amount.Type: GrantFiled: June 3, 1994Date of Patent: March 5, 1996Assignee: The United States of America as represented by the Administrator of the U.S. Environmental Protection AgencyInventors: Charles L. Gray, Jr., Karl H. Hellman, Michael J. Safoutin