GB1299337A - Air heating box for filaments - Google Patents

Abstract

1299337 Air heating box for filaments BABMAG BARMER MASCHINENFABRIK AG 13 July 1971 [13 July 1970 22 Jan 1971] 32793/71 Heading B5B [Also in Division F4] An air heating box 1 for heating a plurality of thermoplastic filaments e.g. a yarn, indicated by the chain-dotted line 9 comprises a heating unit 5 arranged near the base of the box, an inlet for the filaments in the box, and yarn travel reversing members 16 which are guided into and held in the box by rods 12, whereby in use filaments pass into the box through the inlet, are reversed in their direction of travel by the reversing members, and emerge from the box through the inlet. As shown in Fig. 2, the heating system may consist of several heating elements 6 and 7 extending horizontally over the entire length of the box, and preferably travelling the entire width of the box in addition. As shown, the preferred form of box is one the internal horizontal cross-section of which tapers substantially upwards in a vertical direction, the vertical cross-section being preferably of trapezoidal form. The box preferably comprises an inner box 2 and an outer box 3, the two boxes being made of light weight sheet metal, with a layer of heat insulating material 4 arranged between them. As shown, the inlet by means of which the filaments enter and leave is in the base of the box, but the box may alternatively be so constructed that the filaments enter and leave the box from above. The filaments are threaded into the heating box and reversed therein by means of threading and guiding means 10 which project inside the box and which consist of a guide tube 11 and a rod 12 displaceably guided therein. Guide tube 11 is inserted at its upper end into an insertion sleeve 13 fixed to the cover, whilst the inlet end is fixed by means of clip 14 to the box 1. The guide tube is suitably of square cross-section and is provided on that side shown in Fig. 1 with a longitudinal slot (not shown). A bracket (not shown) which carries a filament-reversing member 16 and which is arranged on the upper end of the rod 12, projects through the slot. Filament 9 approaches the reversing member 16 during its upward travel path 17 and leaves it during its downward travel path 18. Threading is effected by release of the locking catch 20 which engages in a locking opening of the guide tube 11, the rod 12 is withdrawn by its handle 19 from the box 1 to such an extent that the reversing member 16 is positioned beneath the bottom of the heating box and the filament is placed over the reversing member, after which the rod is again pushed upwards until the catch snaps into the corresponding position in the guide tube. Two or more yarn reversing members may be fixed to one rod, and the yarn reversing members may be vibrated. The heating box may be provided with outlet openings for vapours 26, and with drainage outlets 25 for conduits 8, in addition to connections for the introduction of steam 36. Fig. 2 shows the manner in which one row of threading and guiding means 10 may be arranged along each of the inclined longitudinal side walls, being illustrated in a simplified form by the base openings 15 for receiving the guide tubes. The detailed construction of the base openings is shown in Fig. 3 (not reproduced). Fig. 4 shows a modified box 101 the operation of which is generally similar to that of Fig. 1, a filament 107 travelling upwards into the box through slot-openings 106a in the base, being reversed by the reversing roller 109 from which the downwardly travelling length 111 of the filament leaves the box again through 106a. The filament is introduced into the air-heating box by means of rod 112 guided by device 113 and which can be moved up and out by handle 114. To introduce the filament into the box, the rod is withdrawn from the box to such an extent that the reversing member 109 is positioned below the base. As shown, contact plates 115 and 116 are associated respectively with the incoming length 108 and the outgoing length 111 of the filament 107. The contact plates have convex surfaces for the filaments. As shown, the contact plates associated with the incoming filament lengths 108 and with the outgoing filament lengths 111 are provided externally with the same configuration, differing from one another in so far as contact plate 115 functions without any fittings whilst contact plate 116 comprises a thermo-couple 127 and a heating element 128. The temperature indicated by the thermocouple through wires 129 can be compensated by means of the heating element 128 which is preferably in the form of an electrical resistance heater and is preferably accommodated inside the contact plate. The apparatus enables the heat treatment of filaments travelling substantially vertically in textile machines, e.g. texturing machines, drawing machines, draw-winding machines, draw-twisting machines or draw-texturing machines, and in heat-setting processes, to be carried out with an enhanced degree of uniformity of heating.