Patent GB-1516110-A (GB)
Title: Process for the manufacture of a cut-pile fabric
IPC: D06C13/10
Filed: 1975-12-17
Abstract: 1516110 Cutting pile fabrics COTONIFICO CANTONI SpA 17 Dec 1975 [24 Dec 1974] 51571/75 Heading D1S A laser beam is used either to cut the loops of a loop pile fabric to form hooks or to split a face-to-face pile fabric to form separate pile fabrics. In one embodiment, Figs. 1, 2, and 3, a machine for cutting pile loops arranged in rows in a fabric T in the form of an endless band comprises a carriage 5 controlled by a worm 6 driven by a motor 7 to slide on rails 2. The fabric T passes between rollers Rl, R2, R3, R4, the rollers Rl, R2 rotating slightly faster than the rollers R3, R4 to tension the fabric and hold it against shoes 8a, 9a. A second carriage 13 is guided on rails 12 on the carriage 5 and is maintained centered by spring 14, 15. To detect the position of the carriage 13, a screen 17 thereon engages in a milled slot 16a in a detector block 16, compressed air being fed from a source (42), Fig. 5 (not shown), through an aperture in a rim 16b, through the slot 16a and through an aperture in a rim 16c. The carriage 5 is re-centred in relation to the carriage 13 in response to a signal received from the detector 16, the motor 7 being driven in one direction or the other. A beam produced by a laser 26 is transmitted by mirrors 27, 28 and lenses 39a, 39b to an inclined mirror 23 and a convergent focussing lens 18 on the carriage 13. Pressurized fluid is directed by a nozzle 48 into the focus zone of the lens 18 to prevent any extraneous matter reducing the efficiency of the focussed laser beam. The carriage 5 carries a V-section arm 29 pivotable about a rod 30 and stressed by a tension spring 31. The arm 29 carries a guide 32, a cam 33 and a stop 34 for a spring 35 fixed to the carriage 13. The cam 33 and the guide 32 have two degrees of freedom with respect to the arm 29. The cam 33 has two guides 33b engageable in an aperture between two guides 13a, 13b. A bar 36 pivoted to the carriage 5 has a stop tooth 37 and a cam follower 38. The lens 18 concentrates the laser beam to a focus on the guide 32 when this is held, by the bar 36 in its working position engaged in a row of pile loops of the fabric T. If the pressure exerted by the pile loops against the guide 22 becomes greater than the pressure exerted by the spring 35 the cam 33 is pushed in the fabric feed direction F. The cam 33 raises the follower 38, and the arm 29, disengaged from the tooth 37, is pulled to the dash-dot line position of Fig. 2 by the spring 31. Similarly, if this pressure lessens, the spring 35 pushes the cam 33 in the opposite direction to raise the follower 38. As the fabric T moves under the shoes 8a, 9a, the guide 32 is subjected to lateral movements which follow movements of the row of pile loops and the lateral movements of the guide 32 result in similar movements of the carriage 13 so that the focus of the lens 18 follows the guide 32. Every movement of the carriage 13 is followed by a movement of the carriage 5. A blade 32a on the guide 32 cuts any filaments of the pile loops which have not been cut by the laser beam. Preferably the laser is a carbon dioxide laser having an emitted wavelength of 10.6 microns. A fluid control circuit is described, Figs. 4 and 5 (both not shown). In a modification, Fig. 6, the lens 18 and the mirror 23 are inclined at an angle towards the fabric. In another embodiment, Fig. 8, a machine for splitting a face-to-face pile fabric T1, T2, in to two separate pile fabrics wound onto rolls 51, 52 comprises two rollers 53, 54 defining the distance between the backing fabrics Tl, T2 in the separation zone. A laser beam is focussed by a lens 18' and a mirror 23' on a carriage 55 slidable on rails 56, 57 and carrying a drive peg 62 engaged with a fork 63 on a belt 59 drivable by a motor 58. Thus, the carriage 55 is reciprocated so that the focussed laser beam scans a line between the rollers 53, 54 to sever the pile yarns. Fluid is projected into the severing zone by a nozzle 64.