Patent ID: 7748092

Claim:
Apparatus for crimping a plurality of continuous filaments of chemical fibres, joined together in an extended, substantially-rectangular-section tow, of the type comprising a pair of motor-driven drums (Rt, Rb) for supplying tow into a confined chamber (C) where crimping occurs, arranged immediately downstream of said drums (Rt, Rb) and consisting of a pair of opposite plates (Pt, Pb), one of said drums (Rb) being mounted on the frame of the apparatus in a fixed position, free to rotate about its axis, while the other drum (Rt) is mounted, itself free to rotate, on a movable support (S) hinged to the frame (W) of said apparatus, one of said plates (Pb) being mounted on the frame of the apparatus in a fixed position, while the other plate (Pt) is hinged to the same axis of rotation (B) of the corresponding drum (Rt), a tightening force (Rs) being applied to the movable drum (Rt), for imparting a drawing pressure on the tow, and a closure force being imparted to said movable plate (Pt), for imparting a pressure to the crimp-forming chamber (C), characterised in that at least one of said plates (Pt, Pb) is mounted on a respective support (L) through two or more linear guides, provided with a double roller or ball recirculation system, parallel to the progression direction of tow (T), and the longitudinal position thereof is determined by a pair of hydraulic cylinders ( 4 ) which, in the absence of other mechanical or oleodynamic locking systems, maintain said plate, or a portion thereof, pushed against respective fixed abutments ( 3 ), said hydraulic cylinders ( 4 ) and said fixed abutments ( 3 ) being both fixed to said plate support (L), and in that one or more force detection means are arranged between said support (L) and said plate (Pt), for detecting the changes in the tightening torque during apparatus operation, said changes being representative of the variable longitudinal force (Tp) imparted by the filaments of the tow (T) being processed on said plate (Pt).