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MESSRS. SCHNEIDER AND CO’.S WORKS.
lifting, the operation is reversed. As will be seen from the
illustrations, helical teeth have been used nearly every-
where. The larger wheels have cast-steel centres, the
teeth being of cast iron.
The lifting hook is fixed on a swivel frame, which is
hung from the pin on which the lower chain wheel
to one of the cast-iron braces at the end of the girder, and
its path will be best seen from Fig. 105. After passing
over the hook wheel and back over the car wheel, it is led
round the driving wheel on the crab, and then through a
guide back to the other end of the crâne, where, after
passing through a second curvecl guide, it hangs down
Details of 150-Ton Electric Travelling Crâne.
(Fig. 105) is fixed. Great care was taken in the design
and manufacture of this detail. The total lift is 13J metres
(44.34 ft.). The lifting chain is constructed of two rows
of links of steel plate 12.5 millimétrés (| in.) thick, there
being four of these links on each side of the pins. Great
care bas also been taken to insure the perfect flexibility
of the chain, as the wheels over which it runs are small in
diameter, and were the chain. at all stift’ the stresses on it
might be seriously increased. One end of the chain is fixed
freely. The guide supporting the chain is held up by
movable supports, which are displaced by the chain car as
it passes by them, and afterwards return automatically to
their places. The chain weighs 206 kilogrammes per
metre run (138 1b. per foot), and as its total length is
57.34 metres (188.07 ft.), its total weight is 11,800 kilo-
grammes (11.61 tons).
6. Lowering Gear.—-To lower the load a special gear
has been provided, worked by a friction clutch from the