The hoist is
fitted with a stopping and starting valve, by means of which water
under pressure from any convenient source of supply may be admitted or
exhausted from the cylinder. The action in lifting is as follows: The
water pressure forces the piston toward the end of the cylinder. The
piston, by means of the flexible steel rack, causes the toothed wheel
to revolve. The winding barrel, being keyed on the same shaft as the
toothed wheel, also revolves, and winds up the weight by means of the
lifting chain. Two special advantages are obtained by this simple method
of construction. In the first place, twice the length of stroke can be
obtained in the same space as compared with the older types of hydraulic
hoist; and, from the directness of the action, the friction is reduced
to a minimum. This simple method of construction renders the hoist very
compact and easily fixed; and, from the directness with which the power
is conveyed from the piston to the winding drum, and the frictionless
nature of the mechanism, a smaller piston suffices than in the ordinary
hydraulic hoists, and a smaller quantity of water is required to work
them.--_Iron_.
* * * * *
POWER LOOM FOR DELICATE FABRICS.
The force with which the shuttle is thrown in an ordinary power
loom moving with a certain speed is always considerable, and, as a
consequence of the strain exerted on the thread, it is frequently
necessary to use a woof stronger than is desirable, in order that it may
have sufficient resistance.
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