INVERSION OF FOUR BAR CHAIN MECHANISM. IT IS ABOUT SIMPLEST MECHANISM USED IN MACHINES

1. INVERSIONS
SHUBHAM KULSHRESTHA
ME
B.1
1206440105

2. INVERSIONS OF FOUR BAR
CHAIN MECHANISM

3. Inversion means getting different mechanism by
fixing different links of four bar chain mechanism
1 inversion – this inversion is obtained by fixing 1st
link
2nd link acts as a crank
3rd link is acts as a coupler
4th link acts as a rocker
1 INVERSION

4. 2nd inversion
• By fixing 2 link the second inversion is
obtained in which
• 1 & 3 link acts as a crank
• Link 4 acts as a coupler
• The mechanism so obtained is known as
crank-crank or double crank

5. 3rd inversion
• By fixing link 3 the 3rd inversion is obtained in
which
• Link 1 acts as a coupler
• Link 2 acts as a crank
• Link 4 acts as a rocker

6. 4th inversion
• By fixing 4 link the 4th inversion is obtained in
which
• Link 1 & 3 acts as a rocker
• Link 2 acts as coupler

7. SLIDER CRANK CHAIN
• WHEN ONE OF THE TURNING PAIRS OF A
FOUR BAR CHAIN IS REPLACED BY A SLIDING
PAIR, IT BECOMES A SLIDER CRANK
MECHANISM

8. INVERSION OF SLIDER CRANK
MECHANISM
• FIRST INVERSION
• THIS INVERSION IS OBTAINED WHENLINK 1 IS
FIXED WHERE
• LINK 2 ACTS AS A CRANK
• LINK 4 ACTS AS A SLIDER

9. SECOND INVERSION
• THIS INVERSION IS OBTAINED WHEN LINK 2nd
IS FIXED
• LINK 3 ALONG WITH THE SLIDER ACTS AS A
CRANK

10. APPLICATIONS ARE-1.WHITWORTH
QUICK –RETURN MECHANISM
2.ROTARY ENGINE
• IT IS A MECHANISM USED IN WORKSHOPS TO
CUT METALS
• FORWARD STROKES TAKES A LITTLE LONGER
AND CUTS TWHITWORTH QUICK –RETURN
MECHANISMH METAL WHEREAS THE RETURN
STROKE IS IDLE AND TAKES A SHORTER TIME

12. ROTARY ENGINE
• LINK 2 IS FIXED
• LINK 3 IS ROTATED DUE TO PISTON
MOVEMENT
• DUE TO THE ROTATION OF LINK 3 ,LINK 1
ROTATES ABOUT O

13. ROTARY ENGINE

15. THIRD INVERSION
• THIS INVERSION IS OBTAINED WHEN LINK 3 IS
FIXED
• LINK 2 ACTS AS A CRANK
• LINK 4 ACTS AS A ROCKER OR OSCILLATOR
• LINK 1 ACTS AS A COUPLER

16. OSCILLATING CYLINDER ENGINE
• LINK 4 IS MADE IN THE FORM OF CYLINDER
• PISTON IS FIXED TO THE END OF LINK1
• THE PISTON RECIPROCATES INSIDE THE
CYLINDER PIVOTED TO THE LINK 3
• WHEN THE PISTON RECIPROCATES IN THE
CYLINDER ,THE CRANK ROTATES

17. OSCILLATING CYLINDER ENGINE

19. CRANK AND SLOTTED LEVER
MECHANISM
• IF THE CYLINDER OF AN OSCILLATING CYLINDER ENGINE IS
MADE IN THE FORM OF A GUIDE AND THE PISTON IN THE
SLIDER
• LINK 3 IS FIXED
• LINK 2 ACTS AS CRANK
• LINK 5 IS A LEVER

21. FOURTH INVERSION
• IN THIS LINK 4 IS FIXED
• LINK 3 ACTS AS A OSCILLATES ON LINK 4
• WHICH MAKES THE LINK 2 TO OSCILLATES
ALONG THE AXIS OF THE FIXED LINK 4
• APPLICATION: HAND PUMP

22. HAND PUMP
LINK 4 IS MADE IN THE FORM OF A CYLINDER
PLUNGER FIXED TO THE LINK 1 RECIPROCATES IN
IT. IF LINK 4 OF THE SLIDER CRANK MECHANISM
IS FIXED ,THE FOURTH INVERSION IS OBTAINED
LINK 3 CAN OSCILLATE ABOUT THE FIXED PIVOT
B ON LINK 4.THIS MAKES END A OF THELINK 2
TO OSCILLATE ABOUT B AND END O TO
RECIPROCATE ALONG THE AXIS OF THE FIXED
LINK 4

25. DOUBLE SLIDER CRANK MECHANISM
• A FOUR –BAR CHAIN HAVING TWO SLIDING
AND TWO TURNING PAIRS SUCH THAT TWO
PAIRS OF THE SAME KIND ARE ADJACENT IS
KNOWN AS A DOUBLE –SLIDER CRANK
MECHANISM

26. FIRST INVERSION
• THIS INVERSION IS OBTAINED WHEN LINK 1 IS
FIXED
• ADJACENT PAIRS 23,34 ARE TURNING PAIRS
• THE OTHER TWO PAIRS 12,14 ARE SLIDING
PAIRS
• APPLICATION: ELLIPTICAL TRAMMEL

27. ELLIPTICAL TRAMMEL

28. SECOND INVERSION
• IF ANY OF THE SLIDE BLOCKS OF THE FIRST
INVERSION IS FIXED, THE SECOND INVERSION IS
OBTAINED
• LINK 4 IS FIXED, END B OF CRANK 3 ROTATES
ABOUT A
• LINK 1 RECIPROCATES IN THE HORIZONTAL
• APPLICATION :SCOTCH YOKE
• A SCOTCH YOKE IS A DEVICE WHICH IS USED TO
CONVERT ROTARY MOTION INTO SLIDING MOTION

29. SCOTCH YOKE

30. THIRD INVERSION
• THIS INVERSION IS OBTAINED WHEN LINK 3 OF THE
FIRST INVERSION IS FIXED
• LINK 1 IS FREE TO MOVE
• THIS INVERSION IS USED TO CONNECT LINK 2 AND 4
• IF THE ROTATING LINKS 2 &4 OF THE MECHANISM ARE
REPLACED BY TWO SHAFTS
• ONE ACTS AS A DRIVER AND ANOTHER AS A DRIVEN
SHAFTS WITH THEIR AXES
• THEY ARE USED TO CONNECT TWO SHAFTS WHEN THE
DISTANCE B/W THEM IS SMALL
• APPLICATION : OLDHAM’S COUPLING