16-10-2012, 10:36 AM
ASSIGNMENT FOR LOCI OF POINTS
LOCI OF POINTS.doc (Size: 37.5 KB / Downloads: 66)
1. In the four bar chain mechanism O1ABO2 the horizontal fixed link O1O2 and the connecting link AB both are 1200 mm long. O1A is a driving crank and is 400 mm long. O2B is a driven crank and is also 400 mm long. Draw the loci of the points P, M and Q where the point P is on the extension of BA and 300 mm from A, the point M is the midpoint of AB and the point Q is on the link AB 300 mm from B. When both the cranks rotate in the opposite direction.
2. In an offset slider crank chain OBA, the crank OB is 300 mm long and the connecting rod BA is 1000 mm long. Slider A slides in a horizontal guide 150 mm below the horizontal from O. Draw the loci of points P and Q where the point P is a point on the connecting rod BA, 250 mm from B and the point Q is the end point of PQ, a rod attached at right angle to connecting rod AB at P. Take PQ = 200 mm.
3. A straight line AB of 60 mm length rotates clockwise about its end A for one complete revolution and during this period a point P moves along the straight line from A to B and returns back to the point A. If rotary motion of the straight line about point A and linear motion of point P along AB are both uniform, draw the path of point P.
4. Figure i shows the arrangement of a simple crank mechanism. This mechanism consists of two rods with pin joints at A and O. OA is a crank. A moves along a circle with O as fixed axis. B is constrained to move along a horizontal straight line. Trace the complete locus of C, for one complete revolution of A. OA = AB = 30 mm, AC = 50 mm.
5. A link AB of 96 mm length rotates about its centre in the clockwise direction. While the link completes one revolution, the insect walks across the length from end A to the end B and back to A. Plot the locus of the insect assuming the rotation of the link and the motion of the insect as uniform.
6. The crank OA, of the mechanism shown in figure ii rotates clockwise at a uniform speed. During one revolution of the crank OA, the slider E at C slides to D and back to C at a uniform speed. Draw the locus of the point B for one revolution of the crank OA about O. Take OA = 250 mm, AB = BC = 750 mm, CD = 500 mm.
7. A pendulum OC pivoted at O, is 120 mm long. It swings 300 to the right of vertical and also 300 to left of vertical. Insect, initially at O reaches the point C, when the pendulum completes one oscillations. Draw the path of the insect, assuming motion of insect and of pendulum as uniform.