FIG. 72.
WRIGHT SHAW MOTION.
The motion called, after its inventor, the Wright Shaw motion is perhaps more suitable to cotton goods. Indeed, in Manchester, near to which city it was invented and is manufactured, it finds much favour in the check trade. A greatly improved motion has been recently introduced by Mr. Wright Shaw, but as the older form is in commoner use, we will refer to the latter.
FIG. 73.
[Fig. 73] shows a sketch of this machine, in which the parts will be clearly seen. It is the make of Messrs. Henry Livesey, Limited, of Blackburn, but is on the Wright Shaw principle improved. The shuttle box is supported and moved by a rack and pinion; this pinion shaft is actuated by a forked rack supported on a pivot at the end of a lever, so as to gear with either side of another wheel on the pinion shaft. The lever is driven by a cam, and raises and lowers the fork. The pattern chain consists of iron plates which are thin and narrow, thus enabling a longer pattern to be obtained than is possible by the previously described motion. These plates are linked together by elastic bands, and each contains two peg holes, and also one, two, or three larger holes to correspond with the points of the three-pattern chain needles. The pattern chain passes round a square block perforated to correspond with the needles, and driven at the speed of a quarter of a revolution for each two picks. The pegs on it carry the pattern plates round with the block. The needles are arranged horizontally, points facing pattern block. The outer needles regulate whether the right or left leg of the fork shall be in contact with the wheel on pinion shaft, to determine whether the reciprocation shall be upwards or downwards. A hole in either one side or the other of the plate regulates this; should both sides be perforated, the fork remains in its previous position. The fork is raised and depressed by a lever, actuated by one of two cams—one to move the boxes one shelf, and the other to skip a shelf, thus moving two boxes. These cams are changeable, and operate on one end of the lever, while the fork is suspended to the other end. The central needle decides which shall be in action, as it carries a projection which, when pushed back, thrusts the larger sweep cam into action. It is easy, therefore, to understand the action of these cards; three holes give no movement; two holes, with a blank at one side, put the fork into gear with the corresponding side of the pinion wheel; and in the case of two blanks, the one in the centre puts two-box stroke in action, and the side blank puts the fork in gear at one side. One blank at the right side causes a rise, or, at the left side, a fall. The five forms of plate are:—