Sliver guide assembly including a sliver guiding device and a sliver preformer

An apparatus for measuring sliver thickness in a drawing frame, comprising

• (a) a sliver guiding device including
• (1) an inlet for simultaneously receiving a plurality of side-by-side running slivers having an advancing direction;
• (2) sliver combining means defining a plane extending parallel to said advancing direction for bringing the slivers together to form a sliver assembly constituted by a plurality of side-by-side positioned running slivers arranged in said plane and laterally contacting one another;
• the sliver assembly having oppositely located first nd second outermost slivers;
• said sliver combining means comprising oppositely located, converging wall surfaces forming a cross-sectionally closed space;
• (3) an outlet for discharging the sliver assembly from said sliver guiding device;
• (b) a sensor element contacting said first outermost sliver at said outlet;
• (c) positioning means for movably supporting said sensor element;
• (d) a counterelement contacting said second outermost sliver at said outlet;
• (e) biasing means for urging said sensor element into a resilient contact with said first outermost sliver in a direction towards said second outermost sliver, whereby said sensor element undergoes excursions upon variation of thickness of said sliver assembly in said plane;
• said sensor element and said counterelement together defining a restriction through which said sliver assembly passes;
• said sensor element and said counterelement forming part of said combining means;
• (f) transducer means for converting excursions of said sensor element into electric pulses;
• (g) a preformer adjoining said sliver guiding device upstream thereof for causing the slivers to laterally approach one another prior to entering said sliver guiding device from said preformer;
• said preformer having opposite lateral sides, a top side and a bottom side;
• said lateral sides being formed by wall components converging in the sliver advancing direction;
• at least one of said top and bottom sides being open;
• (h) a withdrawing roller pair supported downstream of said sliver guiding device as viewed in said advancing direction;
• said withdrawing roller pair defining a nip through which the sliver assembly passes;
• and
• (i) means for driving said withdrawing roller pair for pulling the slivers through said preformer and said sliver guiding device.