Automatically controlled weigh feeding apparatus

Claim 2

Apparatus for feeding particulate solid material comprising, a container for a quantity of said particulate solid material, an auger type discharge device for discharging material from said container, a conduit for receiving material from said auger type discharge device, a motor, a gear-reduction device for connecting said motor to said auger type discharge device, a scale, said container and auger type discharge device and conduit and motor and gear-reduction device being mounted on said scale, means coupled to said scale for producing an electrical signal proportional in amplitude to the weight determined by said scale; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said motor for controlling the discharge rate of said auger type discharge device in response to said discharge control signal, said means for producing said electrical signal being a linearly variable differential transformer, said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor, said motor comprising a DC motor; said motor drive signal generating means including rectifying bridge circuit means connected to said motor for converting an AC signal to said discharge control signal for driving said motor, said bridge circuit means including a pair of SCR''s having respective gate electrodes and in which said generating means further includes pulsing circuit means having a pair of output means connected to said respective SCR gate electrodes to operate said SCR''s to control said discharge control signal by controlling the rectification of said AC signal, and having an input which comprises said input for said motor drive signal generating means.

Claim 3

Apparatus for feeding particulate solid material as set forth in claim 1, further comprising tachometer means having a mechanical input for detecting the speed of said DC motor, and providing a DC output signal, and means coupling said tachometer output signal to said input for said motor drive generating signal means for combination with said comparison signal.

Claim 4

Apparatus for feeding particulate solid material comprising a container for a quantity of said particulate solid material, an auger type discharge device for discharging material from said container, a conduit for receiving material from said auger type discharge device, a motor, a gear-reduction device for connecting said motor to said auger type discharge device, a scale, said container and auger type discharge device and conduit and motor and gear-reduction device being mounted on said scale, means coupled to said scale for producing an electrical signal proportional in amplitude to the weight determined by said scale; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means is coupled between said control signal generating means output terminal and said motor for controlling the discharge rate of said auger type dicharge device in response to said discharge control signal, said means for producing said electrical signal being a linearly variable differential transformer, said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor, an electrically actuatable auger type feeding device for refilling said container, first detector means for detecting when the quantity of said particulate solid material in said container is less than a desired minimum quantity, second detector means for detecting when the quantity of said particulate solid material in said container is greater than a desired maximum quantity, switching means coupled between said first and second detector means and said means for refilling said container for energizing said electrically actuatable auger type feeding device in response to detection by said first detector means of said desired minimum quantity, and for maintaining said auger type feeding device in said energized state until detection by said second detector means of said desired maximum quantity, said first and second detector means including first and second reference voltage sources, and first and second differential amplifiers each having an output, each having a first input coupled to said LVDT output, and each having a second input coupled respectively to said first and second reference voltage sources; and in which said switching means is a relay circuit including first and second relay control coils coupled for energization to said first ans second differential amplifier outputs respectively, wherein said first reference voltage source is set to provide an output from said first differential amplifier to energize said first relay control coil when said LVDT output corresponds to said desired minimum quantity, and wherein said second reference voltage source is set to provide an output from said secoNd differential amplifier to energize said second relay control coil when said LVDT output corresponds to said desired maximum quantity.

Claim 5

Apparatus for feeding particulate solid material comprising a container for a quantity of said particulate solid material, an auger type discharge device for discharging material from said container, a conduit for receiving material from said auger type discharge device, a motor, a gear-reduction device for connecting said motor to said auger type discharge device, a scale, said container and auger type discharge device and conduit and motor and gear-reduction device being mounted on said scale, means coupled to said scale for producing an electrical signal proportional in amplitude to the weight determined by said scale; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means is coupled between said control signal generating means output terminal and said motor for controlling the discharge rate of said auger type dicharge device in response to said discharge control signal, said means for producing said electrical signal being a linearly variable differential transformer, said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor, an electrically actuatable auger type feeding device for refilling said container, first detector means for detecting when the quantity of said particulate solid material in said container is less than a desired minimum quantity, second detector means for detecting when the quantity of said particulate solid material in said container is greater than a desired maximum quantity, switching means coupled between said first and second detector means and said means for refilling said container for energizing said electrically actuatable auger type feeding device in response to detection by said first detector means of said desired minimum quantity, and for maintaining said auger type feeding device in said energized state until detection by said second detector means of said desired maximum quantity, said first and second detector means including first and second reference voltage sources, and first and second differential amplifiers each having an output, each having a first input coupled to said LVDT output, and each having a second input coupled respectively to said first and second reference voltage sources; and in which said switching means is a relay circuit including first and second relay control coils coupled for energization to said first ans second differential amplifier outputs respectively, wherein said first reference voltage source is set to provide an output from said first differential amplifier to energize said first relay control coil when said LVDT output corresponds to said desired minimum quantity, and wherein said second reference voltage source is set to provide an output from said secoNd differential amplifier to energize said second relay control coil when said LVDT output corresponds to said desired maximum quantity.

Claim 6

Apparatus for feeding particulate solid material comprising, a container for a quantity of said particulate solid material, an auger type discharge device for discharging material from said container, a conduit for receiving material from said auger type discharge device, a motor, a gear-reduction device for connecting said motor to said auger type discharge device, a scale, said container and auger type discharge device and conduit and motor and gear-reduction devide being mounted on said scale, means coupled to said scale for producing an electrical signal proportional in amplitude to the weight determined by said scale; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said motor for controlling the discharge rate of said auger type discharge device in response to said discharge control signal, said means for producing said electrical signal being a linearly variable differential transformer, said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor, an electrically actuatable auger type feeding device for refilling said container, first detector means for detecting when the quantity of said particulate solid material in said container is less than a desired minimum quantity, second detector means for detecting when the quantity of said particulate solid material in said container is greater than a desired maximum quantity, switching means coupled between said first and second detector means and said means for refilling said container for energizing said electrically actuatable auger type feeding device in response to detection by said first detector means of said desired minimum quantity, and for maintaining said auger type feeding device in said energized state until detection by said second detector means of said desired maximum quantity, said motor comprising a DC motor; said motor drive signal generating means including rectifying bridge circuit means connected to said motor for converting an AC signal to said discharge control signal for driving said motor, said bridge circuit means including a pair of SCR''s having respective gate electrodes; and in which said generating means further includes pulsing circuit means having a pair of output means connected to said respective SCR gate electrodes to operate said SCR''s to control said discharge control signal by controlling the rectification of said AC signal, and having an input which comprises said input for said motor drive signal generating means.

Claim 7

Apparatus for feeding particulate solid material comprising, a container for a quantity of said particulate solid material, an auger type discharge device for discharging material from said container, a conduit for receiving material from said auger type discharge device, a motor, a gear-reduction device for connecting said motor to said auger type discharge device, a scale, said container and auger type discharge device and conduit and motor and gear-reduction devide being mounted on said scale, means coupled to said scale for producing an electrical signal proportional in amplitude to the weight determined by said scale; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said motor for controlling the discharge rate of said auger type discharge device in response to said discharge control signal, said means for producing said electrical signal being a linearly variable differential transformer, said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor, an electrically actuatable auger type feeding device for refilling said container, first detector means for detecting when the quantity of said particulate solid material in said container is less than a desired minimum quantity, second detector means for detecting when the quantity of said particulate solid material in said container is greater than a desired maximum quantity, switching means coupled between said first and second detector means and said means for refilling said container for energizing said electrically actuatable auger type feeding device in response to detection by said first detector means of said desired minimum quantity, and for maintaining said auger type feeding device in said energized state until detection by said second detector means of said desired maximum quantity, said motor comprising a DC motor; said motor drive signal generating means including rectifying bridge circuit means connected to said motor for converting an AC signal to said discharge control signal for driving said motor, said bridge circuit means including a pair of SCR''s having respective gate electrodes; and in which said generating means further includes pulsing circuit means having a pair of output means connected to said respective SCR gate electrodes to operate said SCR''s to control said discharge control signal by controlling the rectification of said AC signal, and having an input which comprises said input for said motor drive signal generating means.

Claim 8

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional in amplitude to the weight determined by said weighing means; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal, electrically actuatable means for refilling said container, first detector means for detecting when the quantity of said fluid substance in said container is less than a desired minimum quantity, second detector means for detecting when the quantity of said substance in said container is greater than a desired maximum quantity, switching means coupled between said first and second detector means and said means for refilling said container for energizing said electrically actuatable refilling means in response to detection by said first detector means to said desired minimum quantity, and for maintaining said refilling means in said energized state until detection by said second detector means of said desired maximum quantity.

Claim 9

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional in amplitude to the weight determined by said weighing means; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal, electrically actuatable means for refilling said container, first detector means for detecting when the quantity of said fluid substance in said container is less than a desired minimum quantity, second detector means for detecting when the quantity of said substance in said container is greater than a desired maximum quantity, switching means coupled between said first and second detector means and said means for refilling said container for energizing said electrically actuatable refilling means in response to detection by said first detector means to said desired minimum quantity, and for maintaining said refilling means in said energized state until detection by said second detector means of said desired maximum quantity.

Claim 10

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional to the weight determined by said weighing means; first circuit means having an output terminal and having an input coupled to said electrical signal means for providing a rate signal at said output terminal which is proportional to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said first circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal, second circuit means having an output terminal and having an input coupled to the first circuit means output terminal for producing an output which is directly proportional to the acceleration or deceleration of the feed rate, means coupled between the output terminal of said second circuit means and said control signal generating means for maintaining said control signal constant during the time that said output of said second circuit means exceeds a predetermined level.

Claim 11

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional to the weight determined by said weighing means; first circuit means having an output terminal and having an input coupled to said electrical signal means for providing a rate signal at said output terminal which is proportional to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said first circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal, second circuit means having an output terminal and having an input coupled to the first circuit means output terminal for producing an output which is directly proportional to the acceleration or deceleration of the feed rate, means coupled between the output terminal of said second circuit means and said control signal generating means for maintaining said control signal constant during the time that said output of said second circuit means exceeds a predetermined level.

Claim 12

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional in amplitude to the weight determined by said weighing means; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in Amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal, a second differentiator circuit means having an output terminal and having an input coupled to the first differentiator circuit means output terminal for producing an output voltage having a magnitude which is directly proportional to the acceleration or deceleration of the feed rate, voltage sensing circuit means coupled between the output terminal of said second differentiator and said control signal generating means for maintaining said control signal constant during the time that said output voltage of said second differentiator circuit means exceeds a predetermined level.

Claim 13

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional in amplitude to the weight determined by said weighing means; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in Amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal, a second differentiator circuit means having an output terminal and having an input coupled to the first differentiator circuit means output terminal for producing an output voltage having a magnitude which is directly proportional to the acceleration or deceleration of the feed rate, voltage sensing circuit means coupled between the output terminal of said second differentiator and said control signal generating means for maintaining said control signal constant during the time that said output voltage of said second differentiator circuit means exceeds a predetermined level.

Claim 14

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional in amplitude to the weight determined by said weighing means; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal; said means for producing said electrical signal being a linearly variable differential transformer; said means coupled between said discharging means and said control signal generating means including an electric motor for driving said discharging means; and said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor; second differentiator circuit means having an input connected to said output terminal of the first differentiator circuit means, voltage sensing circuit means having an input coupled to an output terminal of said second differentiator circuit means, an indicating meter for providing a visual indication of the discharge rate of said fluid substance as it is discharged from said container, signal holding means having an input coupled to the first differentiator circuit means output to provide an indicating signal to said indicating meter, said voltage sensing circuit means having an outuput coupled to said signal holding means and said comparator for completing feedback paths in said signal holding means and comparator during the time that said second differentiator circuit means has a voltage output in excess of a predetermined level for the purpose of maintaining constant outputs from said comparator and signal holding means during said time.

Claim 15

A weigh feeding apparatus comprising a container for a prefilled substance; means for discharging said substance from the container at a controllable rate; means for weighing said container prefilled with said substance; means coupled to said weighing means for producing an electrical signal proportional in amplitude to the weight determined by said weighing means; differentiator circuit means having an output terminal and having an input coupled to said electrical signal means, wherein said differentiator circuit means is for differentiating said electrical signal to provide a rate signal at said output terminal which is proportional in amplitude to the discharge rate of said substance from said container; control signal generating means having an output terminal, and having an input terminal connected to said differentiator circuit means output terminal, wherein said control signal means is for generating at its output terminal a discharge control signal which is a function of the amplitude of said rate signal; and means coupled between said control signal generating means output terminal and said means for discharging said substance, for controlling the discharge rate of said discharging means in response to said discharge control signal; said means for producing said electrical signal being a linearly variable differential transformer; said means coupled between said discharging means and said control signal generating means including an electric motor for driving said discharging means; and said control signal generating means including a reference signal source, a comparator having first and second inputs connected respectively to said reference signal source and said differentiator circuit means output terminal, and having an output for providing a comparison signal in response to said signals from said reference source and differentiator circuit means, and motor drive signal generating means having an input connected to said comparator output, and having an output which provides said discharge control signal for controlling the speed of said motor; second differentiator circuit means having an input connected to said output terminal of the first differentiator circuit means, voltage sensing circuit means having an input coupled to an output terminal of said second differentiator circuit means, an indicating meter for providing a visual indication of the discharge rate of said fluid substance as it is discharged from said container, signal holding means having an input coupled to the first differentiator circuit means output to provide an indicating signal to said indicating meter, said voltage sensing circuit means having an outuput coupled to said signal holding means and said comparator for completing feedback paths in said signal holding means and comparator during the time that said second differentiator circuit means has a voltage output in excess of a predetermined level for the purpose of maintaining constant outputs from said comparator and signal holding means during said time.

Claim 16

A weigh feeding apparatus as set forth in claim 8 wherein said voltage sensing circuit means comprises a differential amplifier having an output terminal and having an input terminal coupled to the output terminal of said second differentiator circuit means, a reference voltage source, for indicating a maximum desired deviation in acceleration or deceleration of the feed rate, coupled to a second input terminal of said differential amplifier, a relay control coil coupled for energization to said output terminal of said differential amplifier, said relay having normally closed contacts which are openable upon energization of said coil for completing said feedback paths in said signal holding means and comparator.