ES308897A1 - Method for packaging tow - Google Patents

Abstract

Continuous filament crimped tow is deposited in folded layers in a receptacle by means of a feed tube (which may be of rectangular crosssection) the lower delivery end of which is traversed within the receptacle in two different directions. The deposited tow is lowered relative to the tube by control apparatus responsive to the depth of tow in the receptacle. In the machine shown in Fig. 1, tow 40 passes through a guide 38 and rotating feed rollers 32, carried on a traversing frame 33, and falls freely through a tube 36, oscillating about a shaft 37, so that the delivery end of the tube moves between points F, F' and E, E' in the directions shown to distribute the tow in a pattern within a bin 44. A light beam is directed from source 41 onto a photoelectric switch 42 so positioned that, as the beam is interrupted by a layer of tow in the bin, the switch initiates operation of a hydraulic system whereby a cylinder 43 lowers the bin 44 incrementally to maintain the tow bed level 39 at a constant height. When the bin has reached the limit of its downward travel, a sliding door or false bottom therein is opened to allow the accumulated tow to be supported by an underlying hydraulic ram which thereafter is lowered under the control of switch 42 until the deposition of tow required for a bale is completed. The tow is then cleared from the bin 44, prepared for baling/packaging and removed from the machine as the bin is restored to its topmost position, with the sliding door closed, to commence another cycle of operations. In another machine, Fig. 5, the tow, fed by double nip rollers carried on a traversing frame, is distributed within a stationary bin by a tube 55 oscillating about a shaft 70 carried on an extension 82 of the frame. The deposited tow accumulates until it approaches the lower end of the tube whereupon the sliding door is opened so that the tow is supported by an underlying hydraulic ram which thereafter lowers the tow incrementally under the control of a photoelectric cell 57 until a bale quantity of tow has accumulated. When the tow first interrupts a light beam previously impinging on another photoelectric cell 76, the operation of hydraulic apparatus is modified to change the length or speed of oscillation of the tube. Thus, when a manually operated selector switch 77 is in position 1, it normally feeds a limit switch 64 but, when the light beam to cell 76 is interrupted, another limit switch 87 (with a different setting of stops 75) is activated. The switches are connected electrically to a four-way, solenoid controlled, pilot pressure operated valve 80 which alternately reverses the flow of oil through cylinder 60 and, according to which switch is effective, so the longer or shorter stroke of the tube 55 is determined. When switch 77 is in position 2 and the light beam to cell 76 is uninterrupted, a diverter valve 81 is energised and oil flow is directed by control valve 79 to determine the first speed of oscillation of tube 55: when the beam is interrupted, diverter valve 81 is deenergised and oil flow is directed by flow control valve 78 to produce the second speed of oscillation. The positions of the stops 75 or the speed of flow of liquid to the tube-oscillating cylinder 60 may be changed gradually and automatically.