GB955848A - Improvements relating to warp let-off motion in looms - Google Patents

Abstract

955,848. Warp let-off motion. APPARATEFABRIK A.G. HUTTWILL. March 28, 1961 [March.29, 1960], No. 11315/60. Heading D1E. The warp from a beam 1 passes round fixed roller 89, then round an auxiliary backrest 63 and a main backrest 61, both carried by levers 54 pivoted on a fixed shaft 49. Movement of the levers 54 under gradual changes in the tension of the warp are transmitted by links 53 to frames 48, also pivoted on the shaft 49, to control the drive of the warp beam as described below. Movement of the backrests under sudden changes in tension during shedding and beat-up are resisted by dashpots acting on the frames 48. In addition, a cam turns a shaft 45 carried by the frames 48 to rock the levers 54 during beat-up, thereby increasing the warp tension, the tendency of this action to displace the frames 48 downwards being resisted by the dashpots. Controlling let-off. A rod 17 reciprocated by the slay acts through a bellcrank lever 15, 19 and a rod 20 to oscillate a lever 27, which acts through a rod 18 to oscillate a shaft 12 coupled by bevel gearing 13 to the input of a one-way clutch 7; the clutch behaves as a ratchet and drives the beam 1 through a worm 6. The end 20a of the rod 20 is guided at a constant radius from a shaft 22 and also slides in a groove in the lever 27; the rod 18 is pivoted directly on the lever 27, which is itself pivoted at 26a on a carriage 26 slidable on fixed rods 25. The carriage has rack teeth 26b meshing with a pinion 31 on the shaft 22, which carries another pinion 73 meshing with teeth 71 in the frame 48. Movement of the frame about its pivot 49 rotates the shaft 22, causing the carriage to move to the right or left and thereby altering the distance between the pivot 26a and the end 20a of the rod 20; the amplitude of oscillation of the lever 27, and hence the increments of rotation of the beam, are thereby varied.