Linkages and Joints for Robotics - 3
Slider crank is used to convert circular to linear motion. It has three revolute and one prismatic joint. Link 2 is attached to motor, as the link2 move circularly it imposes a linear motion in 4.
2.)Double slider mechanism has 4 links, 2 revolute joints and 2 prismatic joints
Examples: Car wiper
(The wiper of car works like this. The motor drives the link 2 in a circular motion, which ultimately causes link 4 & 6 oscillate)
You can use this concept while making a legged robot to swing robot legs.