| 192 | = 12 picks to the round |
| 16 |
For driving outside tappets, as in [Fig. 39], a driving wheel on the crank-shaft and two intermediate wheels are generally used. The tappets are placed on the bottom shaft outside the loom, but they are loose upon the shaft, and can, of course, be made to revolve at a different speed to the shaft, either in the same or in the opposite direction. This system of driving the tappets is shown at [Fig. 66]. The wheel A, on the crank-shaft, drives the wheel B, on an intermediate stud; the wheel C, on the same centre, drives the tappet wheel D.
FIG. 66.
To find the wheel on the crank-shaft, or the first driver, the other wheels being as follows: first driven wheel, B, 36 teeth; second driver, C, 12 teeth; tappet wheel, D, 120 teeth.
Multiply the two driven wheels together, and divide by the given driver multiplied by the picks to the round, thus—
| 36 × 120 | = 40 first driver, A. |
| 12 × 9 |
To find the second driver for eight picks, the other wheels being: first driver, A, 20; first driven, B, 40; second driven, D, 60.
The given driver multiplied by the picks to the round, 20 × 8 = 160; the drivens multiplied together, 40 × 60 = 2400; 2400 ÷ 160 = 15 wheel required.
To find either of the driven wheels, multiply the two drivers and the picks together, and divide by the driven given wheel, thus—