The Mechanical Handling and Storing of Material

24 THE MECHANICAL HANDLING OF MATERIAL for flour mills and granaries are best made of good textile material, preferably stout ■cotton webbing. Leather is not advisable, as it never runs as true as a woven band. The elevator top, if of wood, should always be made in two halves, so that the spindle and pulley can be readily removed for repair if necessary, without dismantling the elevator. The top and bottom spindles must be perfectly level, or the belt will run continually to one side—a fault that is often not discovered until the edges of the webbing begin to fray out. In erecting flour-mill elevators the holes in the floor should be sufficiently large for the elevator trunk to fit easily, and the trunk should not be tigs. 19 to 21. General Arrangements of Cable-chain Elevator, showing Driving and Tightening Gears. fixed to the floor, but held in its correct position by wooden fillets, so that should the floor spring under an accumulation of sacks the weight will not be on the elevator leg, nor will the latter be affected by the vibration of the floor. Iron elevator trunks are often used in fireproof buildings. A very neat way of making them is to use four pieces of sheet iron, the edges of which are slightly bent, while a small pipe open on one side is pushed over these edges in order to fasten them together. If the trunks are made of wood, the point where two boards join should be fitted with iron tongues in order to prevent leakage of dust. The best and safest plan is to drive each elevator by a separate pulley. Not more