摘要 |
An apparatus and method for measuring the distance between center lines in pairs of cords located in a web of cords. A laser beam passes through an expander which enlarges the beam. The enlarged beam is directed by mirrors to a prism and cylindrical lens through a cube beam splitter to form a line of light. The prism, cylindrical lens and beam splitter are mounted in a carriage. The carriage moves along a track which is orthogonal to the cords in the fabric, with the fabric either being stationary or moving with respect to the track. The line of light is directed against the cords by a lens and the reflected light is collected by the cube beam splitter and converted by an electronic detector into a wave form, amplified and has its apex detected by an analog picking circuit. A train of short pulses is generated, the apexes of which correspond to the center lines of the cords. The cord spacing measuring is determined from the elapsed time between cord center lines multiplied by the scan velocity of the moving carriage.
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