Helical bar strip chart recorder

Claim 2

A recorder for recording a graph of a variable value comprising a plurality of adjacent dot printing means arranged in a row each operable to print a dot in any selected one of adjacent dot positions along a print line extending in the direction of said row, each dot printing means comprising a single dot marker having at least a portion movable to each of the dot positions corresponding to such dot printing means and being operable to print a dot at any one of said dot positions along said print line by movement of said portion to the selected dot position and actuation of such dot marker to print a dot at the selected dot position, means to establish a plurality of consecutive analog ranges into which variable value may fall, each of said ranges corresponding to a different one of said dot printing means, and control means to select the dot printing means corresponding to the range in which said variable value falls and to actuate the dot marker of the selected dot printing means to print a dot in position along the print line thereof selected in accordance with where said variable value falls in the range corresponding to the selected dot print means.

Claim 3

A recorder as recited in claim 1, wherein said plurality of dot printing means comprises a helical bar having a plurality of convolutions, and a plurality of marking blades positioned adjacent to said bar, each spanning one of said convolutions, each of said dot markers comprising one of said convolutions and one of said marking blades and being operable to print a dot at the intersection between the blade and said bar when actuated.

Claim 4

A recorder as recited in claim 2, wherein there is provided means to rotate said helical bar continuously about its axis and wherein said control means comprises timing means to actuate the dot marker of the selected dot printing means at a time interval after said helical bar has passed a predetermined start position corresponding to where said variable value falls in the range corresponding to the selected dot printing means.

Claim 5

A recorder as recited in claim 3, wherein said timing means comprises means to generate pulses as said helical bar rotates and means responsive to the number of pulses generated to actuate the dot marker of the selected dot printing means when the number of pulses generated reaches a value corresponding to where said variable value falls in the range corresponding to the selected dot printing means.

Claim 6

A recorder as recited in claim 2, wherein each of said marking blades comprises a hammer operable to strike said helical bar to print a dot.

Claim 7

A recorder for recording a variable value comprising means to convert said variable value into a digital representation, a plurality of adjacent dot printing means arranged in a row, each operable to print a dot in any selected one of a plurality of adjacent dot positions along a print line extending in the direction of said row, each of said dot printing means corresponding to a different value of said digital rePresentation, each dot printing means comprising a single dot marker having at least a portion thereof movable to each of the dot positions corresponding to such dot printing means and operable to print a dot at any one of said dot positions along said print line by movement of said portion to the selected dot position and actuation of such dot marker to print a dot at the selected dot position, and control means responsive to said digital representation to select the dot printing means corresponding to the digital value of said digital representation and to cause the dot marker of the selected dot printing means to print a dot in a position along the print line thereof selected in accordance with the amount that said variable value varies from the value of said digital representation.

Claim 8

A recorder for recording a variable value comprising means to convert said variable value into a digital representation, a plurality of adjacent dot printing means arranged in a row, each operable to print a dot in any selected one of a plurality of adjacent dot positions along a print line extending in the direction of said row, each of said dot printing means corresponding to a different value of said digital rePresentation, each dot printing means comprising a single dot marker having at least a portion thereof movable to each of the dot positions corresponding to such dot printing means and operable to print a dot at any one of said dot positions along said print line by movement of said portion to the selected dot position and actuation of such dot marker to print a dot at the selected dot position, and control means responsive to said digital representation to select the dot printing means corresponding to the digital value of said digital representation and to cause the dot marker of the selected dot printing means to print a dot in a position along the print line thereof selected in accordance with the amount that said variable value varies from the value of said digital representation.

Claim 9

A recorder as recited in claim 6, wherein said plurality of dot printing means comprises a helical bar having a plurality of convolutions, and a plurality of marking blades positioned adjacent to said bar, each spanning one of said convolutions, each of said dot markers comprising one of said convolutions and one of said marking blades and being operable to print a dot at the intersection of the blade and said bar when actuated.

Claim 10

A recorder as recited in claim 7, wherein there is provided means to rotate said helical bar continuously about its axis and wherein said control means comprises timing means to actuate the dot marker of the selected dot printing means at a time interval after said helical bar has passed a predetermined start position corresponding to the amount that said variable value differs from the value of said digital representation.

Claim 11

A recorder as recited in claim 8, wherein said timing means comprises means to generate pulses as said helical bar rotates and means responsive to the number of pulses generated to actuate the selected dot printing means when the number of pulses generated reaches a value corresponding to the amount that said variable value differs from the value of said digital representation.

Claim 12

A recorder as recited in claim 6, wherein each of said marking blades comprises a hammer operable to strike said helical bar to print a dot.

Claim 15

A method of recording a graph of a variable value as recited in claim 11, wherein the movable portions of said dot markers are moved to a selected position and actuated to print a dot at the selected position by cyclically scanning the movable portions of said dot markers through the corresponding segments thereof and timing the actuation of the selected dot marker to print a dot at the selected position as the movable portions of the selected dot marker scans past the selected position.