Caterpillar Inc.

Howard N Cannon

Mark F Sommars

Dennis Henderson Gibson

Ronald Dean Shinogle

Gregory W Hefler

Glen F Forck

Larry Ellis Kendrick

Steven Francis Meister

Kirk S Shively

Jeffrey J Carter, Jr

Raj T Nagarajan

An apparatus for controlling a continuously variable transmission is disclosed. The apparatus includes (i) an input shaft driven by an engine, (ii) an output shaft, (iii) an operator input for generating speed commands, and (iv) a controller operable to receive said speed commands and generate transmission ratio commands which control a ratio of a speed of the output shaft to a speed of the input shaft. An upper transmission ratio limit is defined by first engine speed and a lower transmission ratio limit is defined by a second engine speed. When the speed command requires a transmission ratio command greater than the upper transmission ratio limit, the controller adjusts the transmission ratio command to the upper transmission ratio limit, whereas when the speed command requires a transmission ratio command less than the lower transmission ratio limit the controller adjusts the transmission ratio command to the lower transmission ratio limit. A method for controlling a continuously variable transmission is also disclosed.

Method and apparatus for adjusting transmission ratio commands for a continuously variable transmission

A solenoid including a single coil of windings, an immovable stator, and opposed first and second armatures defining an air gap therebetween. A driving circuit energizes the coil to cause the first and second armatures to simultaneously move toward each other from respective first positions to respective second positions.

Dual armature solenoid

An electromagnetic actuator is disclosed. The actuator includes a core having an inner and outer pole that defines a pole face. A coil of windings is disposed in the core and produces a magnetic field. An armature is moveable between first and second positions in response to the force produced by the magnetic field. A stroke elongation device is disposed adjacent to the outer pole piece and closely spaced from the armature. The stroke elongation device increases the pull-in force of the electromagnetic actuator.

Stroke elongation device for an electromagnetic actuator

An improved electronically-controlled fluid injector system comprises a fluid storage chamber and a direct-operated check. Pressurization of fluid in the storage chamber begins before the start of fluid injection. Fluid injection begins by hydraulically unbalancing the check. Fluid injection sharply ends by hydraulically balancing the check to allow a biasing device to close the check. The present invention provides improved control of several fluid injection parameters, including higher peak fluid injection capability and less fluid injection pressure drop at the end of injection, resulting in improved engine performance and lower emissions, noise, and wear.

Electronically-controlled fluid injector system having pre-injection

An actuation valve for a hydraulically-operated fuel injector includes an actuator having a plunger and a spool valve coupled to the plunger. The spool valve includes a high pressure port and is operable by the actuator to selectively place the high pressure port or the low pressure port in fluid communication with an injection mechanism of the injector.

Direct-operated spool valve for a fuel injector

An electrohydraulic assembly for actuating a moveable control element is provided. A valve body has two fluid ports, and a central bore. A core is disposed in spaced proximity from the valve body. An armature is rectilinearly translatable between first and second positions relative to the core. First and second electromagnetic coils produce respective electromagnetic forces in response to being energized to cause the rectilinear movement of the armature. A linearly shiftable spool is rigidly connected to the armature. The armature movement causes the spool to displace, which controls fluid flow for actuating the control element. First and second springs provide respective biasing forces to the armature to assist the rectilinear movement of the armature upon the appropriate energization of either of the electromagnetic coils. Advantageously, the retentivity of the core, armature and valve body causes a high latching force to latch the armature at either of the armature positions in response to a respective electromagnetic coil being de-energized.

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Peoria, IL, United States of America

Howard N Cannon