Read the General Instructions above.
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._) Show two methods by which a cotter may be prevented from
slacking back. (6.)
(_b._) Sketch the brasses for a bearing, and show how they are
prevented from turning in the pedestal. (6.)
(_c._) Explain the object of the construction of the connecting rod
end shown in fig. 78. Describe how the adjustment must be made and
how it is locked. (10.)
(_d._) Show the form of the Whitworth screw thread by drawing to
scale a part section of two or three threads taking a pitch of
1-1/2 inches. Figure the dimensions on the sketch. How many threads
to the inch are used on an inch bolt? (10.)
(_e._) Make a sketch showing how the adjustment is made in the
sliding parts of machine tools: as, for example, in the slide rest
of a lathe. (10.)
(_f._) Describe with sketches two methods by which the joints are
made in connecting lengths of cast-iron pipes. (6.)
_Examples to be drawn._
1. Jaw for four-screw dog chuck for 5" lathe. Draw the two views as
shown (fig. 77). Scale full size.
(Note.--The other three jaws of the chuck are not to be drawn.)
(35.)
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.)
[Illustration: FIGS. 77 AND 78.]
[Illustration: FIG. 79.]
* * * * *
First Stage or Elementary Examination. 1886.