. Bulletin. Science. Figure 28.—Plan and section of the Otis system's movable pulley assembly, or chariot. Piston rods are at left. (Adapted from The Engineer (London), July 19, 1889, vol. 68, p. 58.) gearing. The cylinders were of the pushing rather than the pulling type used in the Otis system; that is, the pressure was introduced behind the plungers, driving them out. To the ends of the plungers were fixed smooth-faced sheaves, over which were looped heavy quadruple-link pitch chains, one end of each being solidly attached to the machine base. The free ends ran under the cylinder and made a
. Bulletin. Science. Figure 28.—Plan and section of the Otis system's movable pulley assembly, or chariot. Piston rods are at left. (Adapted from The Engineer (London), July 19, 1889, vol. 68, p. 58.) gearing. The cylinders were of the pushing rather than the pulling type used in the Otis system; that is, the pressure was introduced behind the plungers, driving them out. To the ends of the plungers were fixed smooth-faced sheaves, over which were looped heavy quadruple-link pitch chains, one end of each being solidly attached to the machine base. The free ends ran under the cylinder and made another half-wrap around small sprockets keyed to the main drive shaft. As the plungers were forced oiitward, the free ends of the chain moved in the opposite direc- tion, at twice the velocity and linear displacement of the plungers. The drive sprockets were thereby- revolved, driving up the car. Descent was made simply by permitting the cylinders to exhaust, the car dropping of its own weight. The over-all gear or ratio of the system was the multiplication due to the double purchase of the plunger sheaves times the ratio of the chain and drive sprocket diameters: 2() or about 13:1. To drive the car 218 feet to the first platform of the Tower the plungers traveled only about feet. To penetrate the inventive rationale behind this strange machine is not difficult. Aware of the funda- mental dictum of absolute safety before all else, the Roux engineers turned logically to the safest known elevator type—the direct plunger. This type of elevator, being well suited to low rises, formed the main body of European practice at the time, and in this fact lay the further attraction of a systein firmly based on tradition. Since the piers between the ground and first platform could accommodate a straight, although inclined run, the solution might obviously have been to use an inclined, direct plunger. The only difficulty would have been that of drilling a 220-foot, incline
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Keywords: ., bookauthorunitedstatesdepto, bookcentury1900, booksubjectscience
