One of the most important parts of a cop-winding machine is the traverse motion to guide yarn between the flanges of a bobbin during winding. These are constructed in great variety, but all belong to one of two distinct types, namely, those governed by cams, and those governed by what is termed a “mangle-wheel.” They are also constructed to guide yarn at either a uniform or variable pace between the bobbin flanges. If the traverse of yarn is uniform, bobbins will be wound with a uniform diameter; but if a barrel-shaped bobbin is required, the movement of guide-rails must be differential—quicker towards the extremities, and slower towards the centre of their traverse, with the object of placing a greater quantity of yarn upon them. Traverse motions are usually designed on the compensating principle, so that guide-rails on either side move in opposite directions at the same time, and a falling rail helps a rising one to ascend, thereby requiring less motive power to drive a machine.
FIG. 3.
One of several modifications of a heart-cam traverse motion is shown in [Fig. 2]. In this motion two heart-cams, Q, are set in opposite direction upon a shaft, P, which is driven by a pinion, R, on the tin drum shaft, A, and a train of wheels, S, T, U, V. The cams operate treadles, W, whereby they fall and rise alternately. The free end of each treadle farthest from its fulcrum is connected by means of straps or chains, X, to pulleys; Y, secured to shafts; Z, extending one on each side of the machine, and carrying several pinion wheels, 1, at intervals. The latter engage with teeth in vertical racks, 2, which serve as supports to guide-rails, 3. Thus, as treadles are depressed, guide-rails are raised in a positive manner; but their return is effected by gravitation. The character of movement imparted to guide-rails depends upon the conformation of the cams, which may be constructed to give either a uniform or differential traverse to guide-rails, as desired.
Another modification of a heart-cam motion is illustrated in [Fig. 3]. In this motion a single cam, H, serves to operate both guide-rails, B, by acting upon two treadle bowls, one of which, K, is placed above, and the other, L, below the cam. Treadle bowl K is carried at one end of a lever fulcrumed at O, whilst the other end, M, is connected to a lever, Q. Through the medium of chains and chain pulleys, lever Q operates the guide-rail on the left, whilst the lower treadle, T, operates that on the right.
FIG. 4.
A traverse motion constructed on the mangle-wheel principle, to wind barrel-shaped bobbins, is represented in [Fig. 4], A pinion, B, on the tin drum shaft, A, drives wheel, C, which carries a small pinion, D. Wheel C and pinion D are carried by a bracket that permits of a slight concentric movement of those wheels to enable the pinion to engage alternately on the outside and then on the inside of the mangle-wheel E, with which it gears. On the same stud as the mangle-wheel is a pinion, F, which engages with the teeth of a horizontal rack, G, which is formed with a curved rack at each end. The curved racks gear with eccentric wheels, H, fastened to shafts, I, which carry chain pulleys, J, to wind up or let off the chains connected to the supports of guide-rails. When pinion D revolves on the outside of the mangle-wheel, the latter revolves until the gap K arrives at the pinion, which immediately runs inside the mangle-wheel and reverses its direction, until the gap L arrives at the pinion, which then runs on the outside and again reverses the direction of the mangle-wheel. Thus, rack G is slowly moved from one side to the other, and by acting upon the eccentric wheels H at different distances from their axes, their rotation is quicker or slower, according as the racks are in gear with them at a point nearer to, or farther from, the centre of their shafts respectively. On the same shafts as the eccentric wheels are a number of chain pulleys on which are fastened chains, M, connected to the supports, 2, of guide-rails, whereby the latter are raised and lowered in a manner determined by the eccentric wheels.
FIG. 5.