Automatic control and antibacklash system

Claim 3

An automatic control system for controlling the rate of fluid flow through a fluid line of a fluid system characterized as having backlash, the control system comprising means for measuring the flow rate of the fluid in relation to limits within which the flow rate is to be controlled, a valve means in the fluid line for controlling the flow rate of the fluid, a motor connected to the valve means such that operation of the motor in one direction tends to open the valve means, and operation of the motor in the opposite direction tends to close the valve means, means for generating electrical correction signals whenever the measuring means indicates a flow rate outside the limits, means for operating the motor means in response to the signals in a direction to cause the flow rate to change to within the prescribed limits, means for generating an electrical backlash signal whenever the flow rate varies across both limits, and means for operating the motor means in response to the backlash signal In a direction to remove the backlash from the system.

Claim 4

An automatic control system for controlling the rate of fluid flow through a fluid line of a fluid system characterized as having backlash, the control system comprising means for measuring the flow rate of the fluid in relation to limits within which the flow rate is to be controlled, a valve means in the fluid line for controlling the flow rate of the fluid, a motor connected to the valve means such that operation of the motor in one direction tends to open the valve means, and operation of the motor in the opposite direction tends to close the valve means, means for generating electrical correction signals whenever the measuring means indicates a flow rate outside the limits, means for operating the motor means in response to the signals in a direction to cause the flow rate to change to within the prescribed limits, means for generating an electrical backlash signal whenever the flow rate varies across both limits, and means for operating the motor means in response to the backlash signal In a direction to remove the backlash from the system.

Claim 5

The automatic control system of claim 2 including means for inhibiting the signal generating means whenever the flow rate is within the limits.

Claim 6

The system of claim 2 wherein the measuring means includes an ammeter having upper and lower limit sets, the ammeter including means to generate a signal at one output whenever the meter indicates a measurement below the lower set, and means for generating a signal at another output whenever the meter indicates a measurement above the upper set.

Claim 7

The system of claim 4 wherein the measuring means further includes a tach generator, a flow meter for detecting the rate of fluid flow, means associated with the flow meter for driving the tach generator at a rate proportional to the flow rate, the tach generator including means for generating electrical signals proportional to the rate at which it is driven, and means for feeding the electrical signals from the tach generator to the ammeter for indicating the flow rate of the fluid.

Claim 8

The system of claim 2 wherein the motor means includes a motor having a first winding which when energized causes the motor to operate in a clockwise direction, and a second winding which when energized causes the motor to operate in a counterclockwise direction, and including a gear train mechanically connected between the motor means and the valve means.

Claim 9

The system of claim 2 including means for measuring the quantity of fluid through the fluid system.

Claim 10

The system of claim 2 including means for signalling a malfunction in the fluid system.

Claim 11

The system of claim 8 wherein the signalling means includes means for counting the number of correction signals, means for generating a signal when the count reaches a prescribed number, electrical signalling means, and means responsive to the last named signal for activating the electrical signalling means.

Claim 12

The system of claim 2 including an oscillator means for generating a continuous series of pulses when enabled, means for enabling the oscillator means whenever the flow rate varies to outside the limits, and means for generating the correction signals in response to the output pulses from the oscillator means.

Claim 13

The system of claim 10, including means for adjusting the frequency of the output pulses from the oscillator means.

Claim 14

The system of claim 10 including means for inhibiting the oscillator means whenever the flow rate is within the prescribed limits.

Claim 15

The system of claim 10 wherein the correction signals are pulses of selected widths.

Claim 16

The system of claim 2 including a flip-flop, means for changing the state of the flip-flop output whenever the flow rate varies across both limits, means for generating a strobe whenever the output of the flip-flop changes state, and means for generating the backlash signal in response to the strobe.

Claim 17

The system of claim 14 including means for adjusting the duration of the backlash signal.

Claim 18

The system of claim 2 including first and second switching means, means for causing the motor to operate in a direction so as to close the valve means whenever the first switching means is closed, means for causing the motor to operate in a direction so as to open the valve means when the second switching means is closed, a gating network, means associated with the gating network for gating the correction signals to close the first switching means whenever the flow rate increases above the upper limit, and means associated with the gating network for gating the correction signals to close the second switching means whenever the flow rate decreases below the lower limit.

Claim 19

The system of claim 16 further including means associated with the gating network for gating the backlash signal to close the first switching means whenever the flow rate increases across both limits, and means associated with the gating network for gating the backlash signal to open the second switching means whenever the flow rate decreaseS across both limits.

Claim 20

The system of claim 2, including means for disabling the automatic controls system, a manual switch, and means responsive to operation of the manual switch for causing the motor to operate in a selected direction.