Patent GB-504743-A (GB)
Title: Improvements in method of, and apparatus for, drying fabric and controlling its lineof travel
IPC: F26B13/02
Filed: 1937-10-29
Abstract: 504,743. Drying materials in long lengths. SAMCOE HOLDING CORPORATION. Oct. 29, 1937, Nos. 29661 and 29662. Convention dates, Oct. 30, 1936 and Aug. 26, 1937. [Class 34 (i)] In the drying of a continuous strip of fabric which is propelled through a drying chamber and subjected therein to heated air, the propulsion of different parts of the strip of fabric is controlled acoording to. the looseness or tautness of the fabric at different local positions along the strip and the fabric is automatically maintained in a predetermined path by rectifying different parts thereof , to counteract tendencies of the fabric to leave the path. The tautness or looseness of different runs of the fabric propel different runs at automatically varying speeds. The fabric may pass through the drying chamber in vertical or horizontal runs. In the latter form, several horizontal runs 131, 132 ... 134 occupy a compartment of a drying chamber subdivided by partition walls 35 ... 32, alternate division walls being foreshortened to allow of a continuous flow of air heated by units 37<1>, 127 to pass from the uppermost compartment 38 to the penultimate compartment 38c. The runs of fabric are cooled or conditioned in the lowermost compartment 128 by means of external air entering through an opening 36 which air may then pass into a flue 126 to supply, after heating, the stream of hot air through the upper compartments. The heated air is withdrawn from the compartment 38c through a screen 40 by means of a suction blower. In its passage through the drying chamber the runs of fabric are supported by idle rollers 30 and propelled therethrough by rollers 25, 26. Adjacent some of the latter are the rectifying devices 3<11> which comprise .traction rollers carried from an oscillating frame for centring the strip of fabric. The frame of the latter 177, Fig. 6, is pivotally mounted on an arm 175 attached to a cross-piece 173 supported above one of the propelling rollers, and carries two sets of traction rollers 181 ... 183, each set being angularly disposed to the other. The traction rollers are covered with velvet or plush. The control of the local propulsion of the fabric by varying the speed of a propelling roller 25, Fig. 2, at one side of the drying chamber is, effected by a dancer roller 131, Fig. 4, adjacent the propelling roller 26 at the opposite side of the drying chamber the rise and fall of which due to local tautness or looseness of the fabric slackens or tensions a wire 147 which controls the pressure exerted on a belt driving the roller 25. Similar control of the roller 26 is effected by a dancer roller adjacent the roller 25. The propelling rollers are provided on the same shafts with pulleys 138, Fig. 10, exteriorly of the drying chamber the series of propelling rollers 26 and 25 respectively being driven by belts 64, 65 pressing on the corresponding series of pulleys. The control of the pressure of the belt on a pulley, and therefore the speed of the roller, is effected by mechanism which is duplicated for every roller. This consists of a pivotallymounted lever 142 carrying an idler pulley 144 bearing on the belt and having its end 145 threaded over a sleeve 146 through which one end of the wire 147 passes, the sleeve being spaced from a block 148 affixed to the wire by a spring 150. The dancer rollers are provided with lever arms 157, Fig. 4, the hubs of which surround a shaft 160 to which balancing weights are also attached. The rotation of the shaft 100 slackens or tensions the wire 147 through a connecting arm 154 the wire then effecting the control aforesaid. The dancer rollers are also covered with a fabric to prevent injury. In a modification of the invention, the dancer roller controls the speed of operation of the propelling roller at the same end of the apparatus, the controlling wires being replaced by linkage between the carrier shafts of the dancer roller and the idler pulley bearing on the driving belt. The driving mechanism may also be replaced by sprocket wheels and chains, the sprockets composing the intermediate parts of friction clutches which latter are open or closed by lever and spring mechanism actuated by the dancer roller. In a final modification, a coiled spring is adjusted to vary the compressive action of the clutch the friction being overcome when the fabric tightens, the propelling roller in this case effecting the control of the speed of operation and the dancer roller being omitted.