Patent GB-820841-A (GB)
Title: Textile carding apparatus and method
IPC: D01G15/46
Filed: 1956-02-28
Abstract: 820,841. Carding engines; mounting and clearing rollers. ABINGTON TEXTILE MACHINERY WORKS. Feb. 28, 1956 [June 6, 1955], No. 6149/56. Classes 120(1) and 120(2) In order to provide means for stripping the doffer and cylinder of a carding machine and subsequently restarting the machine automatically without unevenness in the sliver, the web is rolled off the doffer by rolls that, when stopped, hold stationary the broken end of web in such manner that, on restarting, the fibres of the broken end and fresh fibres from the doffer are rolled together. When the machine is to be stripped, the feed roll (not shown), take off rolls 14, 15 and calender rolls 17, 18 are thrown out of gear by means of a handle 95 and a vacuum stripper 125 is manually set to start its traverse. Movement of the handle 95 acts through an eccentric bush to place gears 20, 21 in to and out of mesh, thereby affecting rotation of feed shaft 22. At the same time, a chain 105 is drawn upwardly against a counterweight 106a to move a chain 109 on the other side of the machine that rotates a bushing on a threaded shaft whereby an idler gear in the drive between the doffer and take-off and calender rolls is disengaged. When the take-off rolls stop, the web 304 remains gripped by the rolls 14, 15, as shown in Fig. 12. Continued rotation of the doffer 12 causes the broken end 304a of the web to be combed upwardly and such fibres will not adhere. The diameters of gripped by the roll 14, 15 continue to be held close to the doffer until it is stripped and until a fibrous web has again built up on the doffer 12 after the feed has been restarted. Rotation of the rolls 14, 15 then causes the end 304a to be drawn between the rolls together with a fresh web of fibres in contact with the end 304a. The take-off rolls 14, 15 are preferably made of highly polished steel, but may be of hard rubber, plastic or other material to which the fibres will not adhere. The diameters of the rolls 14, 15 must be related to the average length of the fibres being carded otherwise the length of the end 304a will not produce a satisfactory piecing. A lower roll diameter of 1“ inches and an upper roller diameter of 7/8 inch and a distance between the doffer and upper roll of 0.042 inch are stated to be satisfactory for cotton with average fibre lengths between 0.875 inch and 1.0625 inches. Both rolls 14, 15 are adjustable relative to the doffer 12 by means including wing portions 45a, Fig. 1. Wipers 58, 71, Fig. 12. are urged by springs 62 against the rolls 14. 15. As the stripper 125 traverses across the doffer and cylinder, it strikes a block 122, Fig. 18, fixed to a rod 120 connected through pivoted arm 115 to the handle 95 and with timing mechanism associated with the rolls 14, 15. After striking the block 122, the stripper 125 continues to the end of its traverse where it actuates vacuum timing mechanism adjustable to ensure that the source of suction is not cut off until the doffer is completely stripped. The timing mechanism for restarting the rolls 14, 15 has an eccentric cam 160, Fig. 18, mounted on a pulley 99 carried by an eccentric bush rotatable on the feed shaft 22. Connected to the pulley 99 is a chain 100 in driving connection with the chain 105 on which the counterweight 106a exerts a pull and when the handle 95 is manually operated before stripping, the cam 160 is rotated against the pull of the counterweight 106a, and a dog 162 carried by an arm 163 drops to latch a shoulder 161 of the cam 160. At the same time, lateral movement of the shaft 22 by the handle 95 causes a gear 169 fixed to the shaft 22 to be disengaged from an idler gear 170 rotatable with a gear 172 with which is engaged a timing gear 164 carrying a knock-off member 165 that normally engages an adjustable stop 166. The position of stop 166 in a slot 167 of the arm 163 determines the distance moved by the member 165 before it strikes a roller 165a to cause the arm 163 and dog 162 to be lifted releasing the cam 160 for rotation due to the pull of the counterweight 106a. The member 165 is actuated when the stripper 125 strikes the block 122. When the stripper 125 reaches the end of its traverse, some fibres will remain on the cylinder and will be taken up by the doffer so that it is necessary to maintain suction on the doffer until tnese fibres have been removed. A throw-out arm 232, Fig. 30, attached to pawl 230 releases the pawl at the end of the stripper traverse, thereby placing a pivoted valve plate 210 under pressure from a spring 213. Attached to the valve plate 210 is a shutter 220 that is pressed firmly against a stationary suction cup 229 before release of the pawl 230. When the plate 210 is free to move, a vacuum is created between the, shutter and the cup which is gradually relieved by flow of air past an adjustable bolt. As soon as the vacuum is sufficiently relieved, the spring 213 causes the plate 210 to pivot to its limit and close the valve. Specifications 820,842, 820,843, 820,844 and U.S.A. Specification 2,376,661 are referred to.