Abstract: A method for detecting a low-lift or zero-lift failure mode in a variable valve activation system of an internal combustion engine includes the steps of positioning a piezo-electric element that acts as a radio frequency transmitter relative to a lost motion spring of a two-mode variable valve activation lost motion device, subjecting the piezo-electric element to a compression load when a load from displacement of a lobe of a camshaft acts on the lost motion spring, broadcasting a radio frequency signal each time the piezo-electric element is subjected to the compression load, and evaluating the presence or absence of the broadcasted radio frequency signal in relation to an expected presence or absence of the radio frequency signal. The direct measurement of the mode of each two-mode device is both more reliable and more efficient in the use of engine controller resources compared to currently existing diagnostic methods.

Abstract: A method for detecting a low-lift or zero-lift failure mode in a variable valve activation system of an internal combustion engine includes the steps of positioning a piezo-electric element that acts as a radio frequency transmitter relative to a lost motion spring of a two-mode variable valve activation lost motion device, subjecting the piezo-electric element to a compression load when a load from displacement of a lobe of a camshaft acts on the lost motion spring, broadcasting a radio frequency signal each time the piezo-electric element is subjected to the compression load, and evaluating the presence or absence of the broadcasted radio frequency signal in relation to an expected presence or absence of the radio frequency signal. The direct measurement of the mode of each two-mode device is both more reliable and more efficient in the use of engine controller resources compared to currently existing diagnostic methods.

Abstract: A portable emergency respirator which contains an electrical power supply, a source of compressed air, and a switch which allows one to produce three separate different types of pneumatic outputs from the source of compressed air. In one mode of operation, the output from the source of compressed air provides intermittent positive pressure ventilation to the patient. In a second mode of operation, the output from the source of compressed air is automatically synchronized with the patient's breathing. In a third mode of operation, the output from the source of compressed air is manually controlled by an operator.

Abstract: In one embodiment, a first air flow meter includes a pair of ultrasonic transducers mounted on one wall of a conduit, and an opposite reflective wall is shaped to focus acoustic signals from one transducer to the other. In a second embodiment, the opposite wall is separated into a stepped series of cylindrical reflective surfaces spaced from the transducers by different distances, each surface being one-half wavelength from its adjoining surfaces so that constructive combination of the acoustic signals occurs. For noise of the same wavelength emitted at sources axially spaced from the transducers, the reflective surfaces appear to be spaced by approximately 3/4-wavelength steps so that reflected noise signals tend to cancel.

Abstract: An acoustic fluid flow meter determines the flow velocity or volumetric flow from a measurement of the phase shift of acoustic signals propagated upstream and downstream along an acoustical path in the fluid. High resolution measurements of the phase difference of transmitted and received signals represent the fractional wavelength which exceeds the integral number of waves along the acoustic path. The low resolution determination of the integral and fractional number of waves for each direction is made by measuring the fractional phase shift at one frequency of the acoustic signal and again at a slightly different frequency of the acoustic signal. The difference of those phase shift measurements is proportional to the number of waves along the path for a given direction of propagation. That value is combined with high resolution fractional phase shift measurement to obtain a high resolution total wave number value for each direction of propagation.

Abstract: A fluid flow meter and, more especially, an airflow meter having fast response and very high resolution uses piezoelectric transducers operating near resonance to pass ultrasonic signals upstream and downstream alternately in a flow passage. Transmission signals continue longer than the propagation time to the receiver so that the phase of the received signals can be compared to the transmission signals. The difference of upstream and downstream phase differences is a measure of the air velocity while the sum of those phase differences is useful to determine air temperature. These values along with an air pressure sensor reading are combined to determine mass airflow through the passage. The acoustic transducers are operated near resonance to optimize signal-to-noise ratio.

Abstract: A combined vibration and temperature sensor for an internal combustion engine comprises a piezoelectric disc in mechanical and thermal contact with an engine throttle body and connected electrically in series with an impedance effective to form a voltage divider having a predetermined normalized voltage output at a reference temperature and 50 kilohertz. A 50 kilohertz voltage source is connected across the voltage divider and the vibration signal output provides a temperature signal at 50 kilohertz and an engine vibration signal at a lower frequency such as 5-7 kilohertz.