GB1420360A - Method and apparatus for straightening fabric - Google Patents

Abstract

1420360 Finishing and inspecting fabrics COLTRON INDUSTRIES Inc 10 April 1973 [12 April 1972] 17270/73 Heading D1S Distortions in a forwardly moving fabric being tensioned laterally by a pair of tenter chains 10, 10a are corrected by detecting a skew distortion in the fabric in which one side edge portion of the fabric is skewed forwardly of the opposite side edge portion of the fabric and proportionally varying the forward speed of both of the tenter chains relative to each other, and in direct proportion to each other, to reduce and increase respectively the forward speed of the one and the opposite side edges of the fabric until the skew distortion is corrected without disturbing the mean speed of the fabric. In one embodiment, Figs. 1, 2 and 4, the fabric may be subjected to a wet treatment and is subsequently carried by the chains 10, 10a through a heating chamber 14 and post cooling or fan means 15, Fig. 1, The fabric passes around a feed roll 16 and is advanced and stripped from the chains 10, 10a by rolls 20, 21 which also correct any bowed distortions therein. Rolls 22, 23 deliver the fabric to a collecting means, e.g. a scray or J-box. The chains 10, 10a are driven from a main drive shaft 30 through differential planetary transmissions 36, 36a and the rolls 20, 21 through a similar transmission 37. Each transmission 36, 36a, 37 comprises a hub 40, Fig. 5, keyed to the shaft 30 with an output hub 41 rotatably mounted on the hub 40 and having a pulley 42 thereon. Sun gears 40a, 41a are fixed on the hubs 40, 41 and are engaged by planetary gears 43a, 43b on a shaft 45 carried by a housing 43. Normally the planetary gear means transmits constant speed rotation from the hub 40 or 41 but rotation of the housing 43 reduces or increases the speed of the hub 41. Belts 46, 46a connect the transmissions 36, 36a to the output shaft of a gear box (55), Fig. 3 (not shown), the input of which is driven by a reversible electric skew correction control motor 61, Fig. 4. Belts 47 connect the transmission 37 to the output of a reversible bow correction control motor 65. Signals are sent to the motors 61, 65 reflecting either skew or bow distortions or combinations thereof from detecting means 63, Fig. 1, preferably positioned below the roll 21 so that the fabric is relaxed. Alternative, the means 63 may be located in the region of the chains 10, 10a. Preferably, the means 63 comprises scanning discs 63a, 63b, Fig. 2, located on one side of the fabric and light sources 63c, 63d on the opposite side thereof. Sprockets 13, 13a carrying the chains 10, 10a are secured on output shafts of gear boxes 75, 75a, Fig. 2, whose input shafts 67, 67a, Fig. 4, are driven by shafts 66, 66a through sprocket-and-chain drives 74, 74a. The shafts 66, 66a are driven by the transmissions 36, 36a through belts 72, 72a. The transmission 37 drives, through a belt 80, a shaft 82 which, through a belt 83, drives the input shaft of a speed variator 86 having a manually operable regulator 86a. The variator 86 drives, through a belt or chain 87, the roll 21 coupled to the roll 20 by gearing 90. In operation, in the absence of any skew or bow distortions in the fabric, the pulleys 42 of the transmissions 36, 36a, 37 are driven at constant speed so that the chains 10, 10a are driven at a common and constant speed and the rolls 20, 21 are driven at a constant speed corresponding substantially to the speed of the chains 10, 10a. If, for example, the means 63 detects that the right-hand selvage portions, as viewed in Fig. 2, of the fabric are skewed forwardly of the left-hand selvage portions, the housings 43 of the transmissions 36, 36a are rotated in opposite directions to reduce the speed of the chain 10 a predetermined amount and to increase the speed of the chain 10a by the same amount until this distortion is no longer detected by the means 63. Upon detection of a forward or rearward bow, the speed of the rolls 20, 21 is reduced or increased until this distortion is no longer detected by the means 63. In a modification (not shown), detecting means for controlling the bow correction motor 65 only occupies the position of Figs. 1 and 2 whilst detecting means for controlling the skew distortion motor 61 is located upstream of and adjacent the front end portions of the chains 10, 10a. A scanning sensing device 113, Fig. 1, is provided for sensing variations in the density of the fabric and controls a motor 107 to vary the speed of a shaft 101 driving the feed roll means 16 through a variator 104. In another embodiment, Fig. 7, the transmissions 36', 36a', 37' are not mounted on a common shaft but on parallel shafts 120, 120a, 121. However, the hub (40'), Fig. 8 (not shown), serves as the output and the hub (41') as the input of the transmissions 36', 36a', 37'. Sprockets (42') on the hubs (41') are engaged by a common chain 123, Fig. 7, engaging a sprocket 124 on the shaft 30'. Worm gears 125, 125a, 126 are secured to the housings 43' and are engaged by spiral gears 130, 130a, 131. The gears 130, 130a are mounted on a control shaft 132 and the gear 131 on a control shaft 133. The shafts 132, 133 are connected to the motors 61', 65' corresponding to the motors 61, 65 of Fig. 4.