Stepper motor system for digitally measuring input quantities

Claim 2

A digital system for measuring an input quantity comprising: input means for providing a first force in response to an input quantity to be measured; stepper motor means for providing a second force; measuring means connected to said input means and to said stepper motor means and responsive to said first and second forces such that said measuring means provides an output when said first and second forces reach a predetermined relationship; and, control means connected to said stepper motor means and to said measuring means for causing said stepper motor means to step from a reference position and for counting the steps of said stepper motor means until said measuring means provides said output.

Claim 3

The system of claim 1 wherein said control means comprises reference means for establishing said reference position, said reference position being fixed and establishing a limit of travel for said stepper motor means such that said counting is done only when said stepper motor means is stepped in a first predetermined direction.

Claim 4

The system of claim 2 wherein said reference means comprises a switch which is actuated when said stepper motor means is at said limit.

Claim 5

The system of claim 3 wherein said measuring means comprises a switch which is actuated when said first and second forces reach said predetermined relationship.

Claim 6

The system of claim 4 wherein said control means comprises a counter.

Claim 7

The system of claim 5 wherein said control means comprises start means for resetting said counter and count enable means responsive to said start means for enabling said counter to count pulses from a clock source.

Claim 8

The system of claim 6 wherein said control means comprises up/down means responsive to said start means for conditioning said stepper motor means to apply said second force to said measuring means and responsive to said measuring means for conditioning said stepper motor means to be stepped back to said reference position.

Claim 9

The system of claim 7 wherein said control means comprises step enable means responsive to said start means for supplying pulses to said stepper motor means from said clock source and responsive to said reference means switch for terminating the supply of pulses to said stepper motor means when said stepper motor means is backstroked to its reference position.

Claim 10

The system of claim 8 wherein said input means comprises a pneumatic motor for exerting said first force on said measuring means in response to an input pneumatic signal.

Claim 11

The system of claim 1 wherein said measuring means comprises a switch which is actuated when said first and second forces reach said predetermined relationship.

Claim 12

The system of claim 10 wherein said control means comprises a counter.

Claim 13

The system of claim 11 wherein said control means comprises start means for resetting said counter and count enable means responsive to said start means for enabling said counter to count pulses from a clock source.

Claim 14

The system of claim 12 wherein said control means comprises up/down means responsive to said start means for conditioning said stepper motor means to apply said second force to said measuring means and responsive to said measuring means for conditioning said stepper motor means to be stepped back to said reference position.

Claim 15

The system of claim 13 wherein said control means comprises step enable means responsive to said start means for supplying pulses to said stepper motor means from said clock source and responsive to said stepper motor means being stepped back to said reference position for terminating the supply of pulses to said stepper motor means.

Claim 16

The system of claim 14 wherein said input means comprises a pneumatic motor for exerting said first force on said measuring means in response to an input pneumatic signal.

Claim 17

The system of claim 1 wherein said input means comprises a pneumatic motor for exerting a force as said first input on said measuring means in response to an input pneumatic signal.

Claim 18

The system of claim 16 wherein said control means comprises a counter.

Claim 19

The system of claim 17 wherein said control means comprises start means for resetting said counter and count enable means responsive to said start means for enabling said counter to count pulses from a clock source.

Claim 20

The system of claim 18 wherein said control means comprises up/down means responsive to said start means for conditioning said stepper motor means to apply said second force to said measuring means and responsive to said measuring means for conditioning said stepper motor means to be stepped back to said reference position.

Claim 21

The system of claim 19 wherein said control means comprises step enable means responsive to said start means for supplying pulses to said stepper motor means from said clock source and responsive to said stepper motor means being stepped back to said reference position for terminating the supply of pulses to said stepper motor means.

Claim 22

The system of claim 1 wherein said control means comprises a counter.

Claim 23

The system of claim 21 wherein said control means comprises start means for resetting said counter and count enable means responsive to said start means for enabling said counter to count pulses from a clock source.

Claim 24

The system of claim 22 wherein said control means comprises up/down means responsive to said start means for conditioning said stepper motor means to apply said second force to said measuring means and responsive to said measuring means for conditioning said stepper motor means to be stepped back to said reference position.

Claim 25

The system of claim 23 wherein said control means comprises step enable means responsive to said start means for supplying pulses to said stepper motor means from said clock source and responsive to said stepper motor means being stepped back to said reference position for terminating the supply of pulses to said stepper motor means.

Claim 26

A digital system for measuring an input quantity comprising: input means for providing a first force in response to an input quantity to be measured; stepper motor means for providing a second force, said second force being opposed to said first force; measuring means connected to said input means and to said stepper motor means and having a measuring switch which is operated when said second force overcomes said first force; reference means for establishing a reference position from which said stepper motor is to be stepped at the beginning of each measuring cycle, said reference means including a reference switch which is operated when said stepper motor is returned to said reference position; and, control means connected to said measuring means, to said reference means and to said stepper motor means for initiating said measuring cycle by stepping said stepper motor from said reference position until said measuring switch is operated, for counting the number of steps required to step said stepper motor from said reference position to said position where said measuring switch is operated, and for returning said stepper motor to said reference position where said reference switch is operated.

Claim 27

A digital system for measuring an input quantity comprising: input means for providing a first force in response to an input quantity to be measured; stepper motor means for providing a second force, said second force being opposed to said first force; measuring means connected to said input means and to said stepper motor means and having a measuring switch which is operated when said second force overcomes said first force; reference means for establishing a reference position from which said stepper motor is to be stepped at the beginning of each measuring cycle, said reference means including a reference switch which is operated when said stepper motor is returned to said reference position; and, control means connected to said measuring means, to said reference means and to said stepper motor means for initiating said measuring cycle by stepping said stepper motor from said reference position until said measuring switch is operated, for counting the number of steps required to step said stepper motor from said reference position to said position where said measuring switch is operated, and for returning said stepper motor to said reference position where said reference switch is operated.

Claim 28

The system of claim 25 wherein said control means comprises a counter.

Claim 29

The system of claim 26 wherein said control means comprises start means for resetting said counter and count enable means responsive to said start means for enabling said counter to count pulses from a clock source.

Claim 30

The system of claim 27 wherein said control means comprises up/down means responsive to said start means for conditioning said stepper motor means to apply said second force to said measuring means and responsive to said measuring switch for conditioning said stepper motor means to be stepped back to said reference position.

Claim 31

The system of claim 28 wherein said control means comprises step enable means responsive to said start means for supplying pulses to said stepper motor means from said clock source and responsive to said reference switch for terminating the supply of pulses to said stepper motor means when said stepper motor means is backstroked to its reference position.