Patents Represented by Attorney Richard A. Cederoth
  • Patent number: 5042003
    Abstract: An improved means and method for expanded memory system access and control is disclosed. A logic array in the expanded memory control circuitry which accesses and controls up to two separate expansion boards through the use of static random access memory as register circuits and octal buffers for addressing. The control and access method implemented through a state machine in the logic array provides the operation of the improved expanded memory system to control additional expansion boards and to access the appropriate memory locations.
    Type: Grant
    Filed: July 6, 1988
    Date of Patent: August 20, 1991
    Assignee: Zenith Data Systems Corporation
    Inventors: Steve L. Belt, Robert A. Kohtz
  • Patent number: 4811225
    Abstract: A ratio control system for use in a continuously variable transmission is disclosed in conjunction with an improved technique for operation thereof. Individual gain schedules provide proportional gain in response to a selected one of a number of modes dependent upon clutch input speed, transmission belt ratio, or engine set point. Engine speed set point is determined as a function of a set point schedule in conjunction with a limiter and a filter to provide a gradual response to rapid changes in a throttle input or driver demand signal and vehicle speed. The error signal generated as an output of any of the proportional gain loops is integrated and combined with a null signal to provide a signal to generate a duty cycle for a pulse width modulation controlled electrohydraulic control valve to control the pressure to the primary sheave in a continuously variable transmission system for modifying the belt ratio.
    Type: Grant
    Filed: March 13, 1987
    Date of Patent: March 7, 1989
    Assignee: Borg-Warner Automotive, Inc.
    Inventors: Werner P. Petzold, William P. Umlauf