Patents by Inventor Charles E. Ellis

Charles E. Ellis 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: 5983547
    Abstract: A four bar kinematic artwork retainer that attaches to a frame for securely holding artwork in a frame. The four bar kinematic artwork retainer device is installed for retaining artwork in a frame by positioning the pivot pin interconnecting two point links of the retracted artwork retainer in the inside corner of a frame and then locking the artwork retainer in position wherein the piercing points of the artwork retainer have engaged with the frame. The installed artwork retainer is in intimate contact with the back of the artwork and corner of the frame. The artwork retainer quickly, safely and easily attaches to the frame without modifying the frame or using tools.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: November 16, 1999
    Inventor: Charles E. Ellis
  • Patent number: 5390322
    Abstract: Apparatus and methods for providing memory backup of sterilizer cycle progress in a sterilizer control apparatus are disclosed. The control apparatus includes a microprocessor operable to detect a drop or failure in power from the external source, a RAM for temporary storage of data from the microprocessor, and a clock chip. The clock chip and the RAM receive their power from a backup voltage source which is normally charged by the external power source. The clock chip includes a bit which can be set by receipt of an input signal.A comparator circuit is connected to compare the backup voltage VBAK to the minimum power required for accurately retaining memory in the RAM. When VBAK falls below the minimum required power, the comparator sends a signal to the clock chip to set the bit. After power is restored, the microprocessor checks the bit in the clock, and, if the bit is not set, continues operating the sterilizing cycle from the point at which it was interrupted by the power failure.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: February 14, 1995
    Inventors: Michael J. O'Brien, Charles E. Ellis, Kenneth A. Johnson
  • Patent number: 5258921
    Abstract: Apparatus for and method of enhancing the safety of a vapor sterilizer using a programmed EEPROM signal to show when sterilant is present in the sterilizer chamber. The EEPROM signal electrically controls a door lock on a sterilizer door to prevent injury to an operator and achieve reduced sterilization costs, particularly when power interruptions occur.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: November 2, 1993
    Assignee: MDT Corporation
    Inventor: Charles E. Ellis
  • Patent number: 5164161
    Abstract: Apparatus and methods for proportional control of heating of a sterilizer chamber are disclosed in the application. A sterilizer chamber has heaters mounted on the walls, a wall temperature sensor and a chamber temperature sensor. The controller is operable to adjust the heat input by turning on the heaters for a variable fraction of a selected fixed interval and off for the remainder of the interval. When on the heaters provide a substantially constant heat input per unit time. The fraction of the interval during which the heaters are on is proportional to a temperature differential which comprises a setpoint temperature minus a temperature reading from one of the sensors. The controller has two, or in an alternate embodiment three, operating modes each having a unique temperature differential.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: November 17, 1992
    Assignee: MDT Corporation
    Inventors: Charles H. Feathers, Charles E. Ellis