Abstract: A drive train for a printer is disclosed that provides and maintains a desired tension in the ribbon during transfer of the ribbon between a supply spool and a take-up spool. The drive train is configured to pre-tension the ribbon proximate the driven spool prior to driving the drive roller. During operation, the drive train provides and maintains the requisite tension in the ribbon proximate the driven spool with use of a slip-overdrive assembly. Additionally, the drive train induces a drag on the spool from which ribbon is being unwound with the use of a drag-overrun assembly.

Abstract: A drive train for a printer is disclosed that provides and maintains a desired tension in the ribbon during transfer of the ribbon between a supply spool and a take-up spool. The drive train is configured to pre-tension the ribbon proximate the driven spool prior to driving the drive roller. During operation, the drive train provides and maintains the requisite tension in the ribbon proximate the driven spool with use of a slip-overdrive assembly. Additionally, the drive train induces a drag on the spool from which ribbon is being unwound with the use of a drag-overrun assembly.

Abstract: A preferred embodiment EGR valve permits exhaust gas to be induced into the intake line downstream of the compressor, while minimizing the need to reduce the size of the turbocharger. The preferred embodiment EGR valve exploits variations around the mean pressure in the EGR passage created by the engine cycle by selectively opening when the pressure in the EGR valve exceeds the pressure in the intake line. Thus, exhaust gas is recirculated even when the engine is running near torque peak. The preferred embodiment EGR valve also exploits the higher mean pressure in the exhaust line relative to the intake line at higher engine speeds by remaining open, in order to minimize the energy consumed in opening and closing the EGR valve.

Abstract: A system for limiting rotational speed of a turbocharger includes means for determining a change in an engine operating parameter, a fueling system responsive to a fueling signal to supply fuel to the engine, and a controller determining a fueling command that is air-to-fuel or oxygen-to-fuel control (AFC/OFC) limited under certain engine operating conditions and is otherwise not AFC/OFC limited. The controller is operable to produce the fueling signal as a function of the fueling command, and to further limit the fueling signal according to a turbocharger speed fuel limit in a manner that limits the speed of the turbocharger to a first turbocharger speed limit whenever the fueling command is AFC/OFC limited. The controller is operable to remove the turbocharger speed fuel limit from the fueling signal when the change in the engine operating parameter exceeds a threshold value and the fueling command is thereafter no longer AFC/OFC limited.