A Text Book on Engineering Graphics - Central Board of Secondary ...

MACHINE DRAWING
Example 24:
Solution:
EXERCISES
2.15 KEYS
Sketch freehand the front view and top view of a pan head rivet of diameter
20mm, keeping its axis vertical. Give standard dimensions.
Refer Fig 2.53
Fig 2.53
Note: Assume missing dimensions proportionately
1. Sketch freehand the Front view and Top view of a snap head rivet of diameter
25mm, keeping its axis vertical. Give standard dimensions.
2. Sketch freehand the Front elevation and Plan of a pan head rivet of diameter
25mm, keeping its axis vertical. Give standard dimensions.
3. Sketch freehand the Front view and Top view of a 60° counter sunk flat head rivet
of diameter 20mm, keeping its axis vertical. Give standard dimensions.
4. Sketch freehand the Front view and Top view of a flat head rivet of diameter
20mm, keeping its axis vertical. Give standard dimensions.
Key is piece of metal which is used to fasten two parts together,
specially to join two circular parts together. For example,
pulleys, flywheels etc. are joined to the shaft by means of a key.
See fig 2.54. Key is also used to prevent the relative movement
between the shaft and the parts mounted on it. Whenever
required, it can be removed easily. So key is one of the
temporary fasteners. The groove cut on the shaft to
accommodate a key is called key seat and the corresponding
groove in the matting piece is called key way.
0.7d
Ø1.6d
Ød
Ød
FRONT VIEW
TOP VIEW
PAN HEAD RIVET
KEYSEAT KEY
SHAFT
d 20
0.7d 14
1.6d 32
KEY IN POSITION
Fig 2.54
KEYWAY
ENGINEERING GRAPHICS 81
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