Mdt Corporation

Other

Charles E Ellis

Kenneth A Johnson

Michael J O'Brien

Charles H Feathers

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.

Toggle actuated artwork retainer

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. If the bit is set, the cycle is restarted from the beginning.

Apparatus and method for retaining cycle memory in electronic sterilizer

The electronic microprocessor controller of a sterilizer includes a circuit board functionally controlled by software. The software includes a fist user operation mode for normal operation of the sterilizer. A diagnostic operation mode is initiated by insertion of a jumper in the circuit board, and provides for repetitive cycle operation without opening the door, quickly advancing to a cycle phase, without completion of intervening phases, printing of variables not available in the user operation mode, and calibration of the circuitry.

Control means including a diagnostic operating mode for a sterilizer

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.

Automated purge control of sterilizers

Apparatus and methods for detecting pressure changes within the chamber of a pressure vessel are disclosed. The apparatus includes a pressure transducer which is gauge-referenced to atmospheric pressure and has bi-directional capability of determining pressure changes above and below atmospheric pressure. The transducer is structured to provide frequency output and is therefore connected directly to a microprocessor. The microprocessor includes structure programmed to compensate for variations in existing ambient atmospheric pressure.

Apparatus and method for measuring pressure changes within pressure

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.

Proportional temperature control of a sterilizer

The application is directed to methods and apparatus for venting a pressurized sterilizer chamber having a liquid load within it. A sterilizer chamber is provided with a pressure sensor for sensing the chamber pressure and a vent channel with an associated vent valve. The vent valve is opened to vent pressure from the chamber, and has an orifice providing a maximum flow coefficient substantially larger than a standard bleed valve. A microprocessor-based sterilizer controller monitors chamber pressure and opens and closes the vent valve. The venting phase is regulated by means of a series of vent cycles. An individual vent cycle is intiated by starting a software timer to time a preset interval. The controller records a starting chamber pressure and opens the vent valve. The controller monitors the chamber pressure, and when the pressure has dropped from the starting pressure by a selected maximum amount, closes the vent valve until the timer interval has elapsed. If the maximum pressure drop is not achieved in the given interval, the vent valve remains open as the next vent cycle is started.

Method of venting a sterilizer

A temperature monitoring system provides a first, coarse temperature output signal, and a second, fine temperature output signal based on the first, coarse output signal. The fine output signal has a higher resolution than the coarse output signal, and permits fine temperature control of an apparatus at a variable control output. The fine output signal is automatically calibrated upon switching from the coarse to the fine signal.

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Phelps, NY, United States of America

Charles E Ellis