Patent GB-925803-A (GB)
Title: Textile treating apparatus
IPC: D06C7/00
Filed: 1961-03-22
Abstract: <PICT:0925803/IV(a)/1> <PICT:0925803/IV(a)/2> A device for advancing a tow from an area at one pressure level to an area at a different pressure level comprises a bellows interconnecting said areas, first means at one end of the bellows for gripping the tow and preventing the passage of the pressure medium, second means at the other end of the bellows for gripping the tow and preventing the passage of said pressure medium and means connected to the other end of the bellows for reciprocating said other end.  The device has particular application in feeding continuous filamentary tow into and out of an annealing chamber and one such application is shown in Fig. 1.  Tow 22 is passed from a supply source (not shown) down through the hollow shaft 28 through the connecting pipe 40, between inflatable tubes 46 and 48, which to start with are in an uninflated position (Fig. 2) through flap-valve 64 and into the annealing chamber 10.  The tow 22 is then passed around the guide 20 up through the open flap p  valve 641, through open inflatable tubes 461 and 481 and thence upward through hollow shaft 281 to a suitable take-up means (not shown). Sufficient tow is placed within the chamber 10 so that it is in a relaxed condition to permit shrinkage during the annealing operation. Steam is passed under pressure through conduit 12 into the chamber 10.  With piston 34 in the up position as shown in Fig. 1 the sealing tubes 46 and 48 are inflated to grip the tow and form a seal between the hollow shaft 28 and the bellows section 60.  At the same time piston 341 is in the down position and tubes 461 and 481 are inflated to grip the tow and seal the passage.  At this time exhaust vent valves 70 and 701 are closed.  As the steam pressure builds up in chamber 10 steam is vented through vents 66 and 661 to equalize the pressure above and below the flap valves 64 and 641 thereby allowing these valves to fall open.  Piston 34 is then actuated in a downward direction moving the tubes 46 and 48, gripping the tow between them, downwards and dropping the tow through open flap valve 64 into chamber 10.  Either simultaneously with or immediately after the downward movement of piston 34 the piston 341 is moved upwards to lift the sealing tubes 461 and 481 to pull tow upward through the open flap valve 641 out of chamber 10.  At this point both the vent valves 70 and 701 are opened so that steam escapes from the area above the flap valves 64 and 641 and these are forced close.  Sealing tubes 46 and 48 are deflated and piston 34 is moved upwards so that with the tow held by flap valve 64, tubes 46 and 48 ride up over the tow and take up a position ready for the next cycle.  Similarly on the withdrawal side when the vent valve 701 is opened and flap valve 641 is forced closed the sealing tubes 461 and 481 are deflated and moved downwards by a downward stroke of piston 341 ready for the next cycle.  Valves 70 and 701 remain open only for an instant and after they close, tubes 46, 48, 46,1 and 481 are again inflated and the cycle is repeated so that the tow is moved continuously although stepwise through the annealing chamber 10.  In a second embodiment the sealing tubes are replaced by further flap valves and in a third embodiment there are provided two pairs of tow advancing means, one of each pair lying between the other pair, and operating in conjunction with a central horizontal chamber to pass the tow therethrough.  One pair of sealing and gripping units act together to move the tow, to say the right, whilst the other pair in an open condition move to the left and then the second pair close, gripping the tow and then move to the right whilst the first pair open and move to the left thus moving the tow through the chamber.