The preceding examples sufficiently illustrate the process of tracing out the speed of all the different shafts; for by the same process we can trace the speed of any number of shafts throughout all their windings, even to the remotest department of any factory. The speed per minute of the cross shafts, which give motion to all the machinery in both the carding and spinning rooms, should always range from 88 to 90 revolutions. By the preceding examples the speed of the cross shafts will be found to be 90 revolutions per minute. When the speed of the cross shafts is known, the speed of all the different machines in either the carding or spinning departments, may be easily ascertained. Commence with the spinning department. To find the speed per minute of the fly on the jenny. RULE.-Begin first at the cross shaft, and trace out all the driving and driven pulleys and drums separately, from the large driving pulleys, on the cross shaft, to the fast and loose belt pulleys on the axle of the fly on the jenny. Multiply the diameters of all the driving pulleys and drums together, and their product by the speed of the cross shaft. Then multiply the diameters of all driven pulleys and drums together, and with their product divide the product of the drivers as found above; the result will be the revolutions of the fly per minute. Say the large driving pulleys, upon the cross shaft, are 20 inches in diameter; likewise suppose that all the belt drums, and belt pulleys, are all the same diameter, viz. 18 inches. Required the revolutions of the fly or rim per minute. EXAMPLE. Driving drums and pulleys. Speed of cross shaft per minute, Driven drums and pulleys. 90 20 Diameter of top speed pulley 18)1800(100 revolutions per minute Say the wheel, on the same shaft with the pulleys, contains 74 * In all calculations of this kind where the drivers and driven are separated and multiplied together with a view to ascertain their relative speed, should wheels, containing the same number of teeth or drums, or pulleys of the same diameter, occur on both sides, these may be omitted in the operation. In these examples such are therefore omitted in the operation. teeth, and working into the wheel, of 84 teeth, on the axle of the fly. Speed per minute of belt pulleys, 100 Teeth in the wheel, 74 84)7400(88.09 revolutions of the fly per minute on the first speed. Say the wheel, on the same shaft with the pulleys, contains 84 teeth, and working into the wheel, of 74 teeth, on the axle of the fly. Speed per minute of belt pulleys, 100 Teeth in the wheel, Teeth in the wheel, 84 74)8400(113.5 revolutions of the fly per minute on the second speed. The revolutions of the fly being known-to find the revolutions of the front roller of the jenny per minute. RULE. Begin at the bevel wheel, on the axle of the fly, and trace out the driving and driven wheels from it to the wheel on the front roller. Multiply the number of teeth in the drivers together, and their product by the revolutions of the fly, and multiply the number of teeth in the driven together. Divide the product of the former by the product of the latter, and the result will be the revolutions of the front roller per minute. Revolutions of the fly per minute, 88.09 or first speed. Teeth in the wheel on under end Wheel on top of bevel shaft, 50)2995.06(59.90 revolutions of the front roller per minute. To find the revolutions of the spindle for one of the fly, and of the spindle per minute. RULE. When the wharves are one inch diameter, multiply the diameter of the fly by the diameter of the drum-band groove in the twist pulley, and divide by the diameter of the fly-band groove. Suppose the diameter of the fly to be 40 inches, fly-band groove in twist pulley 14, and drum-band groove 16 inches. Required the revolutions of the spindle for one of the fly. Do. of fly-band groove, 14.5)640.0(44 revolutions of the spin The revolutions of the spindle for one of the fly being 44, this multiplied by the revolutions of the fly per minute, gives the revolutions of the spindle per minute. 88.09 x 44-3875.96 re Revolutions of fly on the first speed, volutions of spindle per minute on first speed. Revolutions of fly on the second speed, volutions of spindle per minute on second speed. 113.5 x 44-4994 re Note. It is difficult to find any general rule by which the revolutions of the spindle for one of the fly or rim can be exactly ascertained by calculation, because these are often found to vary according to the thickness of the drum and fly-bands, the diameter of the wharves, &c. The older these bands are, they become smaller and sink deeper into the grooves; hence the variations of the spindle in proportion to the fly. The above rule, will be found to come as near the truth as any which has hitherto been suggested. Say the cross shafts which give motion to the various machines in the carding and picking rooms, revolve 90 times per minute. Required the speed of the different machines in these depart ments. To find the speed of the cards per minute. RULE.-Begin at the cross shaft, and multiply its revolutions per minute, by the number of teeth in the wheel, and divide the product by the teeth in the pinion on the card-drum shaft; this will give the revolutions of the shaft per minute. Multiply this by the diameter of the card drums, and divide the product by the diameter of the belt pulleys, on the axle of the card cylinder; the |