The four-bar linkage is the simplest and most common type of linkage, consisting of four links connected by four pin joints. It has one degree of freedom and requires one driver to operate fully. The document discusses different configurations of four-bar linkages like the parallel-crank, nonparallel equal-crank, crank and rocker, and slider-crank mechanisms. Quick return mechanisms are also described which give a tool a slow cutting stroke and fast return stroke.

1. The Four-Bar LinkageLecture NotesReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

2. The Four-Bar Mechanism The simplest and most common linkage is the four-bar linkage. It is a combination of four links one designated as the frame, and connected by four pin joints. Since the four-bar mechanism has one degree of freedom, it is constrained or fully operated with one driver.Reference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

3. DesignationsReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

4. Parallel-Crank Four-Bar LinkageReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

5. Nonparallel Equal-Crank LinkageReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

6. Crank and RockerReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

7. Drag LinkReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

8. Slider-Crank MechanismReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

9. Quick Return Mechanisms Quick-return mechanisms are used in machine tools such as shapers and power-driven saws for the purpose of giving reciprocating cutting tool a slow cutting stroke and a quick-return stroke with a constant angular velocity of the driving crank.Crank-ShaperWhitworthDrag LinkOffset Slider Crank Reference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

10. Crank-ShaperReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

11. WhitworthReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

12. Drag LinkReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

13. Offset Slider CrankReference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin

14. Reference: Kinematics and Dynamics of Machines 2nd Edition by George H. Martin. © 1982, 1969 by McGraw-Hill, Inc. Page 44 – 51. Machines and Mechanisms Applied Kinematic Analysis by David H. Myszka. © 1999 by Prentice-Hall, Inc. Page 18.