links -
Connecting rod (link 3) - Fixed
Crank (Link 2)
Piston and rod ( link 1)
Cylinder (link 4)
Pairs -
Turning – Crank and Connecting rod
Turning – Crank & piston rod
Sliding – Piston rod & Cylinder.
Turning – Cylinder and connecting rod
Construction –
This mechanism is an inversion of Single slider crank chain , which is obtained by fixing connecting rod. It has three turning pairs & one Sliding pair. As shown in figure. both rod & piston form one link . There is no relative motion between rod & Piston . The cylinder is pivoted to frame, due to which whole cylinder is free to oscillate about the frame.
Working –
When crank starts rotating, it causes the piston to reciprocate inside the cylinder. A piston while reciprocating causes the cylinder oscillate about pt.'O' ,because there is no relative motion between connecting rod and piston.
Application –
The mechanism is used where rotary transmitted into oscillating motion. It is used in printing press m/c.