Answer briefly any three, but not more than three, of the following questions, and draw two, but not more than two, of the examples.
Questions.
(a.) Explain how the piston rings in Example 1, fig. 84, are made so that the piston may work steam-tight in the cylinder. How are these rings got into place? (8.)
(b.) Give two views of a double riveted lap joint for boiler-plates. (8.)
(c.) Show by sketches how a wheel is fixed on a shaft by means of a sunk key. Explain how the key may be withdrawn when it cannot be driven from the point end. (8.)
(d.) Give sketches showing the construction of a conical metal lift or puppet valve and seating. (10.)
(e.) With the aid of sketches explain how a piston rod is made to work steam-tight through the end of the cylinder. (10.)
(f.) Explain how the slotting machine ram of Example 8, fig. 85, may be made to move up and down when at work. How is the length of the stroke altered, and what is the object of the slotway in the upper part of the ram? (10.)
Examples to be drawn.
1. Piston for steam-engine. Draw and complete the two views shown (fig. 84), the top half of the left-hand view to be in section. Scale 1⁄2 size. (30.)