An Introduction to Machine Drawing and Design Part 12

2. Connecting rod end. Draw the two views as shown, partly in section (fig. 78). Draw full size. (35.)

3. Hooke's coupling. Draw the three views shown (fig. 79), adding any omitted lines where the views are incomplete. Draw to scale of 1/4 full size. (35.)

[Ill.u.s.tration: FIGS. 77 AND 78.]

[Ill.u.s.tration: FIG. 79.]

First Stage or Elementary Examination. 1886.

INSTRUCTIONS.

Read the General Instructions (page 102).

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._) Give sketches showing how the cutting tool of a lathe or other machine is secured in place. (6.)

(_b._) Make a sketch of a stud, describe how it is screwed into place, and state some circ.u.mstances under which it is used in preference to a bolt. (6.)

(_c._) Give sketches showing one method of attaching the valve rod to an ordinary slide valve. (6.)

(_d._) Sketch a connecting rod end, with strap, gib, and cotter.

Explain the use of the gib. (10.)

(_e._) Explain the use of the quadrant for change wheels for a screw-cutting lathe shown in Example 1, fig. 80, by making a sketch showing it in place on a lathe with wheels in gear. (10.)

(_f._) Sketch one form of hanger suitable for supporting mill-shafting.

(10.)

_Examples to be drawn._

1. Quadrant for change wheels for screw-cutting lathe. Draw the two views shown (fig. 80). Scale half-size. (35.)

2. Crank-shaft. Draw the two views as shown, partly in section (fig 81). Scale 1/8 full size. (35.)

3. Ball bearing for tricycle. Draw the two views as shown, partly in section (fig. 82). Draw full size. (35.)

[Ill.u.s.tration: FIGS. 80 AND 81.]

[Ill.u.s.tration: FIG. 82.]

First Stage or Elementary Examination. 1887.

INSTRUCTIONS.

Read the General Instructions (page 102).

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 Explain how the key may be withdrawn when it cannot be driven from the point end.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.)

2. Plan and sectional elevation of a footstep bearing for an upright shaft (fig. 83). Draw and complete these views. Scale 1/4 size. (35.)

3. Ram of slotting machine. Draw and complete the two elevations shown (fig. 85). The tool-holders must be drawn in their proper positions in the ram, and not separate as in the diagram. Scale 1/4 size. (35.)

[Ill.u.s.tration: FIGS. 83 AND 84.]

[Ill.u.s.tration: FIG. 85.]

First Stage or Elementary Examination. 1888.

INSTRUCTIONS.

Read the General Instructions on p. 102.

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._) Give sketches showing how the separate lengths of a line of shafting may be connected together. (8.)

(_b._) What is the object of using chipping or facing strips in fitting up machine parts? Give one or two examples. (8.)