GB539200A - Improvements in or relating to means for tensioning or stretching artificial filaments or threads during or after production - Google Patents

Abstract

539,200. Apparatus for collecting or stretching artificial filaments. ASHCROFT, D. G., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Feb. 29, 1940, No. 3781. [Class 2 (ii)] [Also in Group IX] A device for tensioning, stretching or holding artificial filaments while permitting shrinkage comprises a rotatable frame having a number of screw-threaded rollers mounted upon it and forming a cage around which a filament can be wound so that it is supported, with threading of the rollers, substantially in the form of a helix, the rollers being so constrained that, while the frame is turning, each roller has a turning movement, relative to the frame, on its own axis and the helix is caused to travel in the direction of its axis. The turning movement of each roller is the same in direction and extent as that of the other rollers. As shown, cylindrical rollers 3 are mounted with their axes parallel to the axis of rotation of the frame 1 which is fixed to the axle 2, driven by a pulley 6, the rollers carrying gears 7 geared to a wheel 8 fixed to the bearing 5 and of the same size as the gears 7 so that, as the frame makes one rotation, the rollers rotate about their axes once in the opposite direction and shoulders 11, at the commencement of the threading of the rollers, remain at the top of each roller and assist the feeding of the filament into the device ; after the frame has completed a rotation the filament has been fed axially along the roller for one pitch of the screw thread and eventually leaves the roller at its outer end and is led away for processing. In a modification, the rollers are geared to the wheel 8 through sprocket gearing so that they rotate twice for each rotation of the wheel and in the same direction. The rollers may be arranged with their axes in radial planes at an angle to the axle 2, so that the filaments are stretched, or allowed to shrink, according to the direction of rotation of the frame. In another form, the rollers are partly cylindrical and partly conical so that, if the rollers are arranged to rotate in the same direction as the frame or in the opposite direction at a speed less than one rotation for each rotation of the frame, the filaments will be stretched as they move from the boundary of the cylindrical part and conical part to the largest diameter of the conical part ; if the rollers rotate in a direction opposite to that of the frame and at a speed greater than one rotation for each rotation of the frame, the filaments will be permitted to shrink, or the effects may be reversed by rotating the frame in the opposite direction and feeding the filaments to the largest diameter of the conical part of the rollers. The rollers may be supported at both ends in a rotating frame, a travelling band being provided at one end of the rollers for assisting the winding of the filaments on the rollers, the filaments being driven through a guide and twisted about the band.