Conveyor memory system

Claim 2

Apparatus for compensating for the effects of the characteristics of a conveyor means at a predetermined measuring point, as the conveyor means traverses said measuring point, comprising: means for detecting a predetermined point on said conveyor means; means for generating a marker pulse in response to the detection of said point, said marker pulse indicating a complete cycle of movement of said conveyor means; means for generating travel pulses in response to movement of said conveyor means, said travel pulses indicating the movement of segments of said conveyor means past said measuring point; means for generating a first signal representing said effects when the conveyor means is not loaded; means for generating a second signal representing said effects of the conveyor means when it is loaded; means for storing said first signal representing said effects of said conveyor means in an address location determined by said marker and travel pulses; means for reading out of said storing means said stored signal in response to said marker and travel pulses; and means for compensating said second signal by said stored signal

Claim 3

Apparatus in accordance with claim 1 wherein said conveyor means is an endless conveyor belt.

Claim 4

Apparatus in accordance with claim 1 wherein said predetermined point on said conveyor means is transparent and said means for detecting said predetermined point comprises a photodetector mounted in juxtaposition with said conveyor means and adpated to detect light passing through said transparent point.

Claim 5

Apparatus in accordance with claim 1 wherein said means for generating travel pulses comprises a toothed wheel driven by said conveyor means and a magnetic pickup device mounted in juxtaposition to said toothed wheel.

Claim 6

Apparatus in accordance with claim 1 wherein said means for detecting the effects of the characteristics of said conveyor means as it traverses said measuring point comprises a load cell for measuring weight.

Claim 7

Apparatus in accordance with claim 1 wherein said storing means comprises a digital storage memory having a capacity of at least M words with N bits per word, where M is a number equal to the number of segments into which the conveyor means is to be divided, and N is a number equal to the number of bits of information required for storing the effects of said characteristics of said unloaded conveyor means.

Claim 8

Apparatus in accordance with claim 1 wherein said storing means comprises a digital memory having a storage capacity of at least M words with 10 bits per word, wherein M is a number equal to the number of segments into which the conveyor means is to be divided.

Claim 9

Apparatus in accordance with claim 1 wherein said means for reading out of said storing means comprises means for addressing said storing means and said means for compensating includes a counter and means for applying the information read out of said storing means to preset said counter to the complement of the effect of said characteristics of a segment of the conveyor means corresponding to the address being addressed by the addressing means.

Claim 10

Apparatus in accordance with claim 1 wherein said means for detecting a predetermined point includes: means for indicating the position of said point on said conveyor means; and a detector mounted in juxtaposition with said conveyor means for cooperation with said indicating means to detect said predetermined point.

Claim 11

Apparatus for compensating the weight of a conveyor belt at a weighing point, as the conveyor belt traverses the weighing point, comprising: means for detecting a predetermined point on said conveyor belt; means for generating a marker pulse in response to the detection of said point, said marker pulse indicating a complete cycle of movement of said conveyor belt; means for generating travel pulses in response to movement of said conveyor belt, said travel pulses indicating the movement of segments of said conveyor belt past said weighing point; weighing means located at said weighing point for providing a first signal representative of the weight of said conveyor belt measured at the weighing point when the belt is loaded; means for providing a second signal representative of the weight of said belt measured at the weighing point when the belt is unloaded; means for storing said second signal generated by said weighing means in address locations determined by said marker and travel pulses; means for reading out of said storing means said stored signal in response to said marker and travel pulses; and means for algebraically subtracting said stored signal from said first signal.

Claim 12

Apparatus for compensating the weight of a conveyor belt at a weighing point, as the conveyor belt traverses the weighing point, comprising: means for detecting a predetermined point on said conveyor belt; means for generating a marker pulse in response to the detection of said point, said marker pulse indicating a complete cycle of movement of said conveyor belt; means for generating travel pulses in response to movement of said conveyor belt, said travel pulses indicating the movement of segments of said conveyor belt past said weighing point; weighing means located at said weighing point for providing a first signal representative of the weight of said conveyor belt measured at the weighing point when the belt is loaded; means for providing a second signal representative of the weight of said belt measured at the weighing point when the belt is unloaded; means for storing said second signal generated by said weighing means in address locations determined by said marker and travel pulses; means for reading out of said storing means said stored signal in response to said marker and travel pulses; and means for algebraically subtracting said stored signal from said first signal.

Claim 13

Apparatus in accordance with claim 10 wherein said conveyor belt is an endless belt.

Claim 14

Apparatus in accordance with claim 10 wherein said predetermined point on said conveyor belt is transparent and said means for detecting said predetermined point comprises a photodetector mounted in juxtaposition with said conveyor belt and adapted to detect light passing through said transparent point.

Claim 15

Apparatus in accordance with claim 10 wherein said means for generating travel pulses comprises a toothed wheel driven by said conveyor belt and a magnetic pickup device mounted in juxtaposition to said toothed wheel.

Claim 16

Apparatus in accordance with claim 10 whErein said storing means comprises a digital storage memory having a capacity of at least M words with N bits per word, where M is the number equal to the number of areas into which the conveyor belt is divided, and N is a number equal to the number of bits of information required for storing the weight effects of each segment of the conveyor belt.

Claim 17

Apparatus in accordance with claim 10 wherein said storing means comprises a digital memory having a storage capacity of at least M words with 10 bits per word, wherein M is a number equal to the number of segments into which the conveyor belt is to be divided.

Claim 18

Apparatus in accordance with claim 10 wherein said means for reading out of said storing means comprises means for addressing said storing means and said means for algebraically subtracting includes a counter and means for applying the information read out of said storing means to preset said counter to the complement of the weight of a segment of the belt corresponding to the address being addressed by the addressing means.

Claim 19

A mass flow control system for use with a motor driving an endless conveyor belt having means for feeding material onto the belt and wherein a signal responsive to the speed of the conveyor belt is generated, said system comprising: means for generating a desired set point signal corresponding to a desired mass flow rate; means for generating a first signal corresponding to the weight effects of a segment of the conveyor belt passing a predetermined weighing point when the conveyor belt is loaded; means for generating a second signal corresponding to the effect of a segment of the belt when it is unloaded; means for storing said second signal; means for reading out of said storing means said stored signal; means for subtracting the stored signal from the first signal to provide a net weight signal; means for multiplying said net weight signal with the signal responsive to the speed of said conveyor belt to provide a mass flow output signal; and means responsive to said set point signal and said mass flow signal for controlling the speed of the motor driving the endless conveyor belt to maintain the mass flow at the desired set point.

Claim 20

A mass flow control system for use with a motor driving an endless conveyor belt having means for feeding material onto the belt and wherein a signal responsive to the speed of the conveyor belt is generated, said system comprising: means for generating a desired set point signal corresponding to a desired mass flow rate; means for generating a first signal corresponding to the weight effects of a segment of the conveyor belt passing a predetermined weighing point when the conveyor belt is loaded; means for generating a second signal corresponding to the effect of a segment of the belt when it is unloaded; means for storing said second signal; means for reading out of said storing means said stored signal; means for subtracting the stored signal from the first signal to provide a net weight signal; means for multiplying said net weight signal with the signal responsive to the speed of said conveyor belt to provide a mass flow output signal; and means responsive to said set point signal and said mass flow signal for controlling the speed of the motor driving the endless conveyor belt to maintain the mass flow at the desired set point.