Drawing unit has a passage structure shrouding the drawing and fiber feed sections for connection to a suction opening to extract cotton dust and debris effectively without spreading

摘要

The drawing unit, to draw fiber webs into slivers for spinning, has a passage structure (DU,D1,DL) which shrouds the drawing section (2). A suction opening (48), with a pipe connection to a suction source, is near an outlet of the passage structure to collect cotton dust. The passage structure (DU,D1,DL) shrouds the fiber feed (3), drawing section (2), the sliver converging units (4,5) and the calender rollers (6a,6b). The passage structure is composed of an upper plate (9a) over the upper drawing rollers (8a-8c), a pair of side plates (9c) mounted at opposite sides of the upper plate (9a), and a lower plate (32) under the fiber feed (3) and drawing (2) sections. A front plate (45) is at the leading side of the drawing section (2). The upper plate (9a) swings on the shaft (11) holding it, upstream of the fiber feed section (3) and higher than it, for selective positioning in the open and closed settings. The roller pressure unit (38) is fitted to the upper plate (9a), to apply pressure on the upper drawing rollers (8a-8c) against the lower rollers (7a-7c) when the upper plate (9a) is in the closed position. The upper plate (9a) has a hole (9d) to secure a holder (15) at the plate under side with a plunger through the hole to press the upper rollers (8a-8c). Carriers fitted at the holder (15) have end bushes to hold the upper rollers (8a-8c) in place. A wiper rod is held at the holder (15) to detach cotton dust from the rubber mantle of each upper roller (8a-8c) when in contact. The upper plate hole (9d) has an elongated shape at a point corresponding to the end bushes of the upper rollers (8a-8c), along the feed direction of the fiber web (F). A guide, which engages the holder (15), is at the under surface of the upper plate (9a) near the elongated hole. A pair of roller frames (13) support the ends of the lower drawing rollers (7a-7c). The width of the upper plate (9a) is sufficiently large so that the gap between the outer sides of the roller frames (13) and the length of the upper plate (9a) is larger than the gap between the fiber feed section (3) and the calender rollers (6a,6b). The passage structure has a center passage (D1) which shrouds the drawing section (2), flanked by an upstream passage (DU) and a downstream passage (DL). A part of each side plate (9c) is an integral part of the upper plate (9a). The lower plate (32) has an opening aligned with the drawing (2) and fiber feed (3) sections, and a hollow guide with a cross section surface which contracts downwards is under the passage structure (DU,D1,DL) opposite the opening. A suction unit is linked to the guide to give a suction air flow through it. The drawing unit main cover (9) extends along the direction of fiber web (F) movement, together with auxiliary covers at opposite ends of it. The upper plate (9a) forms part of the main cover (9), and the auxiliary covers are moved independently into open and closed positions. An Independent claim is included for a drawing unit cleaning action where at least the drawing section (2) is shrouded by a passage (DU,D1,DL), and a suction opening (48) is located near a passage opening, to collect cotton dust. The passage prevents cotton dust spreading, and air is drawn out of the passage through the suction opening.