Solid-state sliver sensor and auto-leveler for textile machine

A sliver monitor for controlling the unit weight of a moving sliver in a textile machine, comprising:

• (a) a support rigidly mounted on a sliver output end of said textile machine;
• (b) a trumpet carried by said support for outputting a condensed sliver;
• (c) at least one strain gauge carried by said support and responsive to strain imposed on said support by movement of sliver through said trumpet;
• (d) analog electrical circuit means carried by said support in electrically communicating relation to said strain gauge, and including:
• (1) a power supply carried by said electrical circuit on said support for outputting an excitation voltage;
• (2) a Wheatstone bridge for receiving the excitation voltage from said power supply and applying the excitation voltage to said at least one strain gauge, receiving a feedback signal from said strain gauge and outputting a low level voltage control signal corresponding to the weight of the sliver passing through the trumpet;
• (3) an amplifier carried by said electrical circuit on said support for amplifying the low level voltage analog control signal from the strain gauges into a high level analog signal suitable for processing in a computer;
• (4) level detector and status indicator means carried by said electrical circuit on said support to detect and indicate proper excitation voltages and proper level output signals;
• and
• (d) motor controller means for receiving the amplified analog control signal and controlling the speed of drafting roll means in response to said amplified analog control signal for pulling the sliver through the trumpet at a predetermined rate to maintain the strain of the sliver moving through the trumpet at a magnitude indicative of a predetermined desired sliver weight;
• and
• (e) data processing and storage means for receiving and storing the amplified analog control signal for further processing.

A method of monitoring the unit weight of a moving sliver in a textile machine, comprising:

• (a) providing a support rigidly mounted on a sliver output end of said textile machine, a trumpet carried by said support for outputting a condensed sliver, at least one strain gauge carried by said support and responsive to strain imposed on said support by movement of sliver through said trumpet, and analog electrical circuit means carried by said support in electrically communicating relation to said strain gauge;
• (b) outputting an excitation voltage from a power supply;
• (c) receiving the excitation voltage from said power supply at a Wheatstone bridge;
• (d) applying the excitation voltage to said at least one strain gauge,
• (e) receiving a feedback signal from said strain gauge and outputting a low level voltage control signal corresponding to the weight of the sliver passing through the trumpet;
• (f) amplifying the low level voltage analog control signal from the strain gauges into a high level analog signal suitable for processing in a computer;
• and
• (g) transmitting the high level analog signal data to a data processing and storage means for receiving and storing the amplified analog control signal for further processing.