Scans Associates, Inc.

Richard L Smith

Kent Van Allen

Peter J Mosher

Ronald K Mudge

Charles E Foerster, Jr

Vernon G Converse, Iii

James M Bordato

Theodore R Bott

Kent V Allen

Frank R Young

Desra N Herbst, Jr

The specification discloses an electronic dynamic balance leak testing system utilizing a 'live zero', wherein a source of test medium at a predetermined desired pressure or vacuum is connected to a part to be tested, and after the part is filled with the test medium, and an interval is provided for the system to stabilize the affects due to wave front oscillations, the test part is momentarily isolated from said test media and a microcomputer system is utilized, both to cause said isolation, and to measure the differential pressure existing at two points during the test. In a modification of our system which can dynamically project leak and accept or reject parts much sooner because of this projection feature, the rate of change of the differential pressure transducer is examined and is compared to a curve which is characteristic of the rate of change of a volume which is experiencing a predominately leak based change of pressure. When the rate of change is determined to be predominately a leak based change, the rate of change is determined to be a 'Qualified Leak' or a qualified curve. In this case, after a predetermined sample time elapses from the point at which the curve was qualified, a reading of leakage is taken, such reading is then extrapolated to a full test time reading and compared to limits to see if a part is to be accepted or rejected.

Method and apparatus for electronic leak testing

The specification discloses a two-directional switched driver for use either independently or in a method of controlling production processes and apparatus therefor. The driver, whether used independently or in a process controller, utilizes polarity signals and a retriggerable timer to produce separate forward and reverse output signals which may be used to drive reversible motors or two-directional actuators by way of standard switching techniques. Examples of such uses are the use of most any reversible motor, or two-directional actuators to control mechanical, pneumatic or hydraulic circuits, such actuators operated by the driver may be rotational or non-rotational in nature.

Two-directional switched driver

A method and apparatus for controlling production processes utilizing a three-state, four-mode process controller which operates on the basis of counteracting any process change by utilizing the difference between a feedback signal related to a current condition of the process and a desired value related to the desired condition of the process, and a signal related to the rate of change between said feedback signal and said desired value signal, to produce a correction signal which is utilized to operate said three-state, four-mode process controller in its three states depending on certain relationships between the value of the desired value and feedback signals, as well as the summation of those values.

Method of controlling production processes and apparatus therefor

The specification discloses a novel method for controlling production processes of a pneumatic, electrical or hydraulic nature and apparatus therefor. The method, and therefore the apparatus for performing said method, counteracts any process change by utilizing the error difference and the rate of change of the error difference between a feedback signal related to a current condition of the process and a desired value related to the desired condition of the process. The error difference and rate of change and then utilized to produce a correction signal which is adapted to remain unchanged as long as the process being controlled, and the desired value signal, both remain in static condition, but which also has a unique look ahead feature such that said correction signal attempts to become saturated as soon as a new desired value is supplied, or a process change occurs. The correction signal, if saturated, is brought out of saturation much faster by using both the rate of change of the actual error difference between said desired value and said feedback signals and the actual error difference between said signals in a manner which is much faster than if only the error difference was used. If said correction signal never does reach a saturation point, or if it is saturated, upon becoming unsaturated, the correction signal is then changed much faster than previously possible by using the rate of change of the error difference, rather than the error difference only.

This invention relates to a method and apparatus for reproducing operating conditions in induced flow devices, such as carburetors and the like, and more particularly to a system for reproducing such operating conditions which may be used in testing systems designed to test induced flow devices. In operation in such a test system, the apparatus of the present invention would cause a given air flow to flow through an induced flow device such as a carburetor, and then would cause the throttle plate of the carburetor to be rotated until the desired manifold vacuum in the carburetor is obtained, at which time the test of the carburetor could take place. By providing a throttle drive controller to move the carburetor throttle at a speed which is proportional to the difference in the manifold vacuum actually present in the carburetor, and the desired manifold vacuum, a very rapid movement of the throttle plate between test points can be had, but at the same time a slow approach to the actual test point, to prevent overshoot, is accomplished. A continuous monitoring of the difference between the manifold vacuum in the carburetor, and the desired manifold vacuum, is accomplished by a continuous reading and comparing of electrical signals, in either a manual or computer controlled system, in which the two signals are first compared to determine which way the carburetor throttle must be moved to approach the desired test point, and then the actual difference between the two signals is computed to determine how many additional pulses must be supplied to the stepping motor forming part of the carburetor throttle drive controller to control the drive as described above. The operations reproducing system of the present invention works equally as well computer or manually controlled, or with sonic or subsonic air flow measuring devices.

Apparatus for reproducing operating conditions in induced flow devices

The specification discloses a method and apparatus forlaboratory testing of carburetors to determine the mass air flow rate and mass fuel flow rate through the carburetor at any desired test point by providing, in addition to the normally required systems, an improved manifold vacuum control system for producing a predetermined air flow at a given manifold vacuum, and an improved hood pressure control system which enables carburetor testing to take place at test points which correspond to different altitudes in which the carburetor may be used. In addition, by providing that these systems be computer controlled, the three-mode controllers normally associated with producing air flow and controlling hood pressure are replaced by a computer which provides output control signals corresponding to that which would be provided by three-mode controllers where the values of rate, reset and proportion are continuously and automatically changed to the optimum value for each test point. In this way it is now possible to perform the laboratory carburetor test completely automatically at many test points in the carburetors operating range more quickly, accurately and reliably, whether or not testing is required at sea level or at any altitude within practicable limits.

Method and apparatus for laboratory testing of carburetors

The specification discloses an improved method and apparatus for determining the time angle of a diesel engine which, in contrast to the present day method, is one which is fast, accurate, and can be readily used on a production line basis. There is disclosed a method and apparatus which, by the utilization of pulses of fixed angular frequency produced by an encoder, and counted between the moment the pressure in the injector line of the cylinder, whose timing angle you are measuring, reaches a predetermined pressure and the moment the piston in the same cylinder reaches top dead center, a number of pulses representing the timing angle of the engine is obtained, which can easily be converted into a reading of the timing angle. The pulses are essentialy counted by producing a signal when the pressure in the injector line reaches a certain predetermined value, after which time all other pressure signals are locked out in a predetermined manner, with the count of pulses being stopped when the next top dead center signal occurs. By providing a lockout period based on degrees of crankshaft rotation for all timing applications, except where the engine being timed in intended to be run at a constant speed, a production diesel engine timing system is provided which gives accurate results, regardless of the speed of the diesel engine, in an accurate and reliable manner.

Method and apparatus for timing diesel engines

This invention relates to a method and apparatus for reproducing operating conditions in induced flow devices, such as carburetors and the like, and more particularly to a system for reproducing such operating conditions which may be used in testing systems designed to test induced flow devices. In operation in such a test system, the apparatus of the present invention would cause a given air flow to flow through an induced flow device such as a carburetor, and then would cause the throttle plate of the carburetor to be rotated until the desired manifold vacuum in the carburetor is obtained, at which time the test of the carburetor could take place. By providing a throttle drive controller to move the carburetor throttle at a speed which is proportional to the difference in the manifold vacuum actually present in the carburetor, and the desired manifold vacuum, a very rapid movement of the throttle plate between test points can be had, but at the same time a slow approach to the actual test point, to prevent overshoot, is accomplished. A continuous monitoring of the difference between the manifold vacuum in the carburetor, and the desired manifold vacuum, is accomplished by a continuous reading and comparing of electric signals, in either a manual or computer controlled system, in which the two signals are first compared to determine which way the carburetor throttle must be moved to approach the desired test point, and then the actual difference between the two signals is computed to determine how many additional pulses must be supplied to the stepping motor forming part of the carburetor throttle drive controller to control the drive as described above. The operations reproducing system of the present invention works equally as well computer or manually controlled, or with sonic or subsonic air flow measuring devices.

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Livonia, MI, United States of America

Richard L Smith