Speed-mul′ti-pli′er.
（
Gearing.) An arrangement of gearing by which pinions are driven from larger wheels, the pinion-shafts carrying large wheels, and so on. It is seen in the motion work beneath the dial of a watch, by which the motion of the center arbor is geared up to drive the minute-hand and seconds-hand.
It is the inverse of the watchmove-ment proper, in which the relatively slow-moving wheel, which receives the first impulse of the spring, becomes the quicker motions of the wheels in the direction of the escapement.
This
gearing-up or
gearing-down, or
speedmultiply-ing or
decreasing, is found in many kinds of machinery.
Fig. 5368 is an arrangement of gearing within a series of pulleys, upon which the driving-belt may be shifted to increase the power or speed of the drum.
See also Nos. 73, 424, 75, 677, 81, 248.
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Variable speed-pulleys. |
In
Fig. 5369, the motive shaft has arms which carry spurwheels engaging the inner gear of the drum, and a pinion which is fast to the second shaft, having similar arms and spur-wheels engaging a pinion on the third shaft.
This may be extended as far is desired; the proportion between the planet-wheels and their pinions regulates the increase of speed gained.
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Multiplying gear. |
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Mowing-machine with speed-multiplying movement. |
Fig. 5370 shows the application of the principle to a mowing-machine.
The slow speed of the ground-wheels is geared up to give a rapid reciprocation to the cutter-bar.
The pinion to which the cam
A is attached terminates a system of speed-multiplying gear mounted upon the main axle; from this gearing motion is communicated to the cutter through the medium of a yoke surrounding the cam, a pitman-rod, cranklever, etc.
