| 摘要 |
<p>1,140,693. Extruder feed systems. BARMER MASCHINENFABRIK A.G. 19 April, 1966 [3 June, 1965], No. 17141/66. Addition to 1,103,925. Heading B5A. [Also in Division B1] The arrangement described in the parent Specification 1,103,925, wherein an axially extending feed pocket 4 communicates with a feed inlet 2 and screw 3, is modified by the provision of a gate 5 which is movable to vary the volume and/or the inlet cross-section of the pocket. As shown, gate 5 is vertically reciprocable and is moved manually by rotation of lever 10 to actuate rack and pinion 11, 9. Gate 5 may be provided with a gas vent (12), Fig. 2 (not shown). Alternatively the gate may be annular and notched as at (14), Fig. 3 (not shown), or in the form of a pivoted cover (15), Fig. 4 (not shown), with or without an end-gate (17) to vary the inlet cross-section of the pocket. In a second embodiment, Fig. 5 (not shown), operation of gate 5 is dependent on capacitance melt-level meters (24, 25), situated within an extraction chamber (23), which control a reversible motor (28), A stirrer (30) is also provided. In a third embodiment, Fig. 6 (not shown), two feed pockets (33, 34) are provided and have corresponding adjustable gates (5, 39), pocket (34) receiving thermoplastics melt pumped from a first melt zone via a conduit (31), a breaker plate (37) and a vacuum gas-extraction chamber (32). In all cases the screw core is of large diameter in the region beneath gate 5 compared with the screw core diameter in the neighbourhood of the feed pocket.</p> |
