Technical Drawing - Exam Papers - Ordinary - 2006 - Engineering
(Compressed Cam Assembly)
(Compressed Linkage Assembly)
A radial plate cam has a minimum radius of
40mm and a camshaft diameter of 22mm.
The cam rotates in a clockwise direction and imparts the
following motion to an inline knife-edge follower:
0° to 180° Rise 60mm with uniform acceleration and
180° to 210° Dwell;
210° to 300° Fall 40mm with simple harmonic motion;
300° to 360° Fall 20mm with uniform velocity.
Draw the profile of the cam.
Include the displacement diagram as part of the solution.
Shown is a link mechanism. A and C are fixed
points. Crank AB rotates in an anti-clockwise direction.
Link BDEF is pin jointed at B and D. Link CD oscillates
about point C.
(i) Using a line diagram to represent the
mechanism, plot the locus of point F for one revolution of
the crank AB.
(ii) Draw the profile of a simple machine guard
about the mechanism with a minimum clearance of 15mm.