Patent GB-524528-A (GB)
Title: Improvements in or relating to the manufacture of threads of glass or other synthetic material
IPC: B29C48/15
Filed: 1939-01-31
Abstract: 524,528. Glass &c. threads; delivering thread; electric conductors; casting metals. SOC. ANON. VETRERIA ITALIANA BALZARETTI MODIGLIANI. Jan. 31, 1939, No. 3312. Convention date, March 22, 1938. [Classes 120 (ii) and 120 (iii)] [Also in Groups XXII, XXIII and XXXVI] Yarn or thread is made from glass or other synthetic filaments by extruding the filaments, laying them on a former between which and the . filament extrusion apparatus there is relative rotation so that a tubular lap is built up on the former with the filaments crossing each other at a constant acute angle and then, simultaneously or subsequently drawing the whole circumference of one end of the tubular lap in a direction along the longitudinal axis thereof to a point whereby the lap is reduced in diameter to form the yarn or thread. The lap may be formed on a rotary conical drum from filaments delivered by a reciprocating extrusion apparatus, the lap being subsequently mounted on a conical drum and the smaller circumference being drawn off by a pneumatic device of the kind described in Specification 508,531 or by a pair of rollers to be wound as a thread upon a core or bobbin. As shown in Fig. 5 the process is continuous, the filaments a being laid on the conical drum 1 and the lap b being drawn from the end 1 of the drum by the pneumatic device 8 to form a network 7 which produces the thread 7<SP>1</SP>; a collar surrounding the drum may be arranged to move the lap towards the delivery end of the drum when the lap has attained a predetermined thickness. A core may be drawn through the lap with the thread which then forms a covering for the core. The former may comprise one or more endless belts upon which the lap is formed and which moves it continuously towards the drawing-off device. As shown in Fig. 9, the former comprises a pair of rings 16, 17 rotatably mounted on a stationary tube 11' and connected by a number of rods 18, 19 rotatably secured in the rings and respectively provided with right and left-handed helical strips 27 extending the length thereof; the ring 16 is driven from a motor 25 and is geared to the rods 18, 19 so that they rotate in opposite directions. The lap b is laid by the reciprocating extrusion device 2 upon the rods 18, 19 and is moved by them towards the end 1<SP>1</SP> where it passes over a conical extrusion of the ring 17, which smooths the' external face of the lap, and passes as a network 7 into a rotating guiding cone 28 to the pneumatic drawing-off device 8, the resulting thread being twisted and passing down a tube 31 to an elbow tube 32 rotatable about a vertical axis and traversed vertically to lay the thread on a bobbin 38 carried on a rotating platform 39 which carries the bobbins successively into line with the axis of rotation of the tube 32. The thread is forced along the tube 32 to the outlet 37 by the fluid in the device 8 and while passing through the tube 31 is treated with a dressing or finishing liquid drawn from a container 44; by arranging the delivery mechanism to rotate at the same speed and in the same direction as the former, an untwisted thread is produced. In the arrangement shown in Fig. 11, the lap b is formed on the interior of a stationary tubular former 46, the filaments being deposited by arms extending from a rotating body 47 supplied with liquid glass &c. from a furnace 49 through a stationary annular conduit 50, the shaft 47<SP>1</SP> of the body 47 being rotated from a motor 68 and reciprocated by reason of an inclined ring 61 on the shaft engaging a stationary roller 62; a receptacle 52 may contain metal of a low melting point which is delivered by a conduit 59 to the interior of the tubular thread as it is drawn from the interior of the former 46 and an insulating material may be supplied from a receptacle 51 by a conduit 60 or a glass coated metal wire may be fed towards the thread being formed. The former may be conical so that the lap is fed downwards by gravity or endless bands operating through slots in the former may be used to convey the lap to the drawing- off device 8, the lap passing from the former into a spring-supported dished cup 53 having a conical surface 57 co-operating with a conical seat 56 on the device 8 to regulate the admission of air into the device and consequently the rate at which the lap is drawn downwards; as the thread is formed the material from the container 51 is drawn into it to form an internal coating for the metal from the container 52. The finished composite thread 7<SP>1</SP> passes through a tube 32a rotatably mounted within a stationary tube 63 and is fed out through the radial outlet 37 and deposited in the form of a helix which is conveyed downwards and forwards by endless bands 64, 65, 67 to the point where it is to be stored and used. Specifications 498,962 and 504,970 also are referred to.