spirally around the doubled bristles, aided by female threads IV made in the nut d. The plunger Q continuing to revolve in the same direction, the wire-bound bunch is projected through the bottom of the nut, and, by its wire binding, is made to screw its way into the hole a in the brush back. The plunger is then slightly and slowly rotated in the reverse direction, to take the twist out of the bristles, and the two plungers P and Q move back to their raised positions for similar action on a succeeding lot of bristles, and so on till the brush is finished.
The means adopted for securing the necessary motions and pauses in the plungers P and Q are as follows :—On the main shaft D (Fig. 397), is a disc A', having in its front face a cam groove o', whose configuration gives the requisite movements and pauses to the hollow plunger P, the connection with the latter being established by a pia or roller pi , travelling in the groove o', and carried by an arm q' , in adjustable attachment by screw nuts with a vertically moving and guided rod r', working a vertical slide s', that carries the hollow plunger P. The inner and doubling plunger Q is worked by an eccentric pin t' on the face of the disc A', the pin moving, as the disc revolves, in and along a slotted cross-head B', mainly of a shape corresponding with the circle in which the pin t' travels, and guided so as to have an intermittent vertical sliding action under the operation of the revolving eccentric pin t'. The upper end of the plunger Q_is attached to the cross-head B' by a screw and annular groove, in order to admit of its having the necessary intermittent rotary as well as vertical move ment. The rotary motion is given for the purpose of wrapping the wire spirally around the double bristles, and to screw the bunch into the hole in the brush back, also to take the twist out of the bristles when the plungers retire. The groove u' in the back of revolving disc A' works a pin v' attached to a lever, and working up and down tbrough a curved slot in the main frame. By these means, an inteimittent up and down motion is communicated to the lever w' (Fig. 396), and through the latter, by means of a pitman x', and slotted adjusting arm y', an intermittent vibratory motion is given to a toothed sector C', which is in gear with horizontal bevel pinion z'. The rotation of this pioion z' in either direction takes place at the close
of the descent of the plungers P Q, and as they commence to move up again. Ou its arbor, it carries a spur wheel a2, that gears with a pinion b2, to rotate the plunger Q as required. The pinion (Fig. 397) turns loosely on a sleeve c2, arranged to loosely surround the plunger Q, and having an internal key or feather that fits a longitudinal groove .19 in the plunger, to admit of the latter sliding up and down through the sleeve, and yet to secure its rotation by the sleeve when the latter is revolved. The rotation of sleeve c2 by pinion b2 is effected by a clutch tension and friction device, consisting in part of half-clutches e2 f2, the former of which is fast to pinion , while the latter is loose on the eleeve, and capable of up and down motion on it towards or from the upper half-clutch e2, under control of a spring 92, which presses at its lower end against an adjusting nut h2 fitting a screw-thread on the sleeve, and presses at its npper end against a loose washer 0, to hear the latter up against a leather or rubber washer 0, which in its turn presses up against a washer or disc 12. on the under side of the lower clutch P. By means of this spring tension and friction clutch, the plunger Q, when being revolved forwards to wrap the wire around the bristles and screw the bunch into the brush-back, is driven with an increased force by reason Of the half-clutches e2 and f2 operating to compress the spring and to increase the friction of the washers 12, h2, P. The force is relaxed when the plunger Q is rotated to free itself from the inserted bunch, by reason of the reverse action of the pinion b2, and dip of the clutch, allowing the spring gl to slightly relax and reduce the friotion of the washers. This prevents the plunger Q, when rotated baekwards, from unscrewing the bunch out of the brush-back. On the plunger Q, is a grooved tapering swell m2, into the groove of which a spring guide n' attached to the rod r' of the outer plunger P enters, in the up stroke of plunger Q, to turn or adjust and ensure the proper relative position of the plunger with the oblique slot e' in the outer plunger, and with the wiring perforations preparatory to the descent of the plunger Q t,o perform its work.