Patent GB-190415426-A (GB)
Title: Improvements in the Shedding-mechanism of Looms for Weaving.
Inventor: PERRY CRANLEY LANCELOT
Filed: 1904-07-11
Granted: 1904-10-20
Abstract: 15,426. Perry, C. L., [Northrop Loom Co.]. July 11. Loom dobbies; shedding - motions; shedding - levers; pattern surfaces. - Shedding- mechanism, especially applicable to looms having more than two shafts of healds, but also applicable t o looms having two shafts only, is constructed on the dobby principle to operate positively the heald shafts in both directions without the employment of strap connections. The mechanism is arranged at the side of the loom to operate upon the shafts from the top, thus leaving the space below the heatds unobstructed. Each heald frame comprises a cross-bar A, supporting a series of metallic healds C of known construction, and two end bars B guided in vertical guideways D. The upper ends of the bars B are pivotally connected to pivoted bent levers E, F connected by a link b. To allow for the slight swing of the bars B, the ends of the cross-bar A fit loosely in the end bars. The lever F is provided with arms carrying rollers c, d, which are acted upon by a tappet G on a pivoted lever to lower and raise the heald frame. Coupler bars H are pivotally connected to the ends of the tappet lever, and are provided at their lower ends with notches g, adapted to be engaged by an actuator projection J on a horizontal bar fixed upon the upper end of a slide K, which is mounted to slide upon vertical rods f. A rod V is pivotally connected to the slide K, and at its lower end to a pivoted lever W. The rod V carries rol:ers w, x engaged by a cam L, which is adjustably fixed to a disc T removably mounted upon the tappet shaft U, so that the slide K is positively moved up and down. The two coupler bars H are held out of engagement with the actuator J, by a single camactuated follower rod M mounted to slide in a guideway in a plate i, and acted upon by a selector cam N. The coupler bars are moved into engagement with the actuator J, when the bar M is free to be pressed back, by means of pivoted bent levers 0 acted upon by springs k. The selector cams N, one for each heald frame, are mounted on a sleeve removably secured to a shaft o. The sleeve is polygonal in cross-section, and the cams have correspondingly-shaped openings, so that the cams may be placed in any desired angular position. The number of faces on the sleeve corresponds to the number of heald frames. The shaft o is intermittently rotated by bevel-wheels r, s from a vertical shaft t, at the lower end of which is fixed a six-pointed star-wheel Q engaged by a cam-rib formed on the rim of a wheel u on the crank shaft S. The cam-rim is so shaped that, at each revolution of the crank shaft, the starwheel is rotated a sixth of a revolution, and the bevel-wheels r, s are arranged so that the shaft o is thereby rotated through a fraction of a revolution corresponding to the number of faces on the sleeve. The cam L is shaped to raise or lower the actuator J to the limit of its motion, and then cause it to move back a short distance into the position in which it can be engaged by or disengaged from the coupler bar H, the coupler bars being locked in their raised and lowered positions by a groove on the tappet G engaging the roller d or c. The actuator is caused to dwell in this position, and, during the dwell, the shaft o receives its partial rotation, so that the bar M is moved to cause the coupler bar H to engage with or be disengaged from the actuator, or the bar M may be unaffected, according to the shape of the cam N. Since both coupler bars H are acted upon by one bar M, to prevent one coupler bar from engaging with the actuator while the other bar is in engagement therewith, the bars are provided with projections at the back of the notches g. During the reciprocation of the actuator, these projections engage, so that the disengaged coupler bar is held away from the actuator while its notch is passing it. Since a heald frame may be raised or lowered by means of either of the bars H, any heald frame may be raised or lowered at any time, or may be left raised or lowered for any desired period.