Emerson Electric Company

Emhart Industries, Inc.

Michael T Clouser

Laurence S Slocum

Michael R DuHack

David J Nelson

Robert S Coulter

Andrew F Schloot

A dishwasher includes a water inlet connectable to a water source. A dishwasher element is operable on water received through the inlet. A flow sensor is in fluid communication with the inlet and is operable to generate a control signal indicative of water flow through the inlet. A control apparatus is connected between the dishwasher element and the flow sensor and is operable to inhibit operation of the dishwasher element in response to the control signal.

Method and apparatus for sensing water flow through a dishwasher including a vacuum switch

Method and apparatus for sensing water flow through a dishwasher including a thermal sensor

A line leak test probe for use on a liquid conduit. A pressure transducer is mounted in mechanical contact with the liquid in the conduit and a temperature transducer is mounted in thermal contact with the liquid. The transducers provide signals to a microprocessor-based circuit which includes a timer. Software stored in the microprocessor analyzes the time rate of change of the pressure to determine if there is a leak. Normally a sequence of three tests are performed: a catastrophic test, a gross test, and a precision test. The catastrophic test exits to the gross test if the rate of change of the pressure is less than a first rate, and the gross test exits to the precision test if the rate of change is less than a second rate which is less than the first rate. The precision test normally cycles until the pressure drops below 4 psi, and then outputs a leak signal if the pressure drops to below 3 psi in 12 minutes or less. If the temperature change during the test is sufficient to account for the pressure change, or the temperature is out of a range where it can be measured, the test aborts without outputting a leak signal.

Line leak test apparatus measuring rate of pressure change in a liquid

A line leak test probe for use in a liquid storage and dispensing system which includes a pump. A pressure transducer provides a pressure signal to a microprocessor-based test circuit. Various conditions descriptive of the pressure versus time curve while the pump is running, such as the pressure will rise above 20 psi when the pump is turned on, drop when the liquid is dispensed, and rise again when the dispenser is turned off, are stored within a software program in the microprocessor memory. The microprocessor calculates an average pressure to average out noise and artifacts in the pressure, and waits for the pressure to drop 2 psi below the average pressure after the pump has been turned off before performing leak tests in order to give the noise and artifacts time to die down.

Line leak test apparatus responsive to pump use

A leak test probe includes a pressure transducer which may be mounted in mechanical contact with liquid in the conduit. The pressure transducer provides a pressure signal to a microprocessor-based circuit which, following software stored in its memory determines if there is a leak in the conduit by measuring the time rate of change of the pressure. The software also analyses the pressure signal and compensates for the effect of gas in the conduit by determining the time rate of change in the pressure immediately after the pump turns off and adjusting a sliding time scale for the leak test depending on the result.

Liquid leak test probe with compensation for gas in line

An elongated bilaminate bender is formed from a pair of piezoelectric ceramic sheets laminated to a conductive metallic strip. In response to an alternating current, the bender bends in a direction substantially perpendicular to its long axis, first one way and then the opposite. One end of a pivot bar is driven by the bender. A spring provides a bias force opposite to the direction that the pivot bar is pushed by the bender, to return the pivot bar when the bender bends in the opposite direction. A pair of pawls attached one on either side of the pivot axis of the bar, alternately drive a ratchet wheel on the bender drive stroke and the return stroke. The ratchet wheel turns a drive shaft. A stop prevents the pivot bar from exactly following the motion of the bender, so that the motion of the drive shaft is independent of voltage fluctuations of the alternating current.

Piezoelectric motor

A control system is provided for controlling a flue damper in a furnace flue. The control system includes a voltage source, a thermostat, a gas valve, and means for moving the flue damper between a closed position and an open position. The moving means includes a timer driven by a motor with a specially wound coil assembly including a first winding and a second winding. The coil assembly further includes a first terminal, a second terminal and a center tap terminal. The control system manipulates the flue damper and heating system during three stages of operation. The flue damper is closed and the furnace is off at the beginning of stage one. The control system opens the flue and turns on the furnace during stage one. The flue damper remains open during stage two. The control system turns off the furnace and closes the flue damper during stage three.

Flue damper control system

A flue damper is rotated 360.degree. in a predetermined direction in 90.degree. increments to be selectively opened and closed in 90.degree. increments. The incremental rotation is accomplished by a motor driven timing mechanism with power to the motor being controlled by the timing mechanism and a single pole double throw relay.

Means controlling a flue damper

A flue damper is rotated 360.degree. in a predetermined direction in 90.degree. increments to be selectively opened and closed in 90.degree. increments. The incremental rotation is accomplished by a motor driven timing mechanism with power to the motor being controlled by the timing mechanism and a solid state switching means selectively energizing and deenergizing the motor.

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Indianapolis, IN, United States of America

Michael T Clouser