Locking Toggle Pliers

 
Click the figure above to activate the associated video simulation file.

WM2D File

Software copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved.

Info

The pair of  locking pliers (vise grip pliers) is used to hold two pieces together at the toggle position of the fourbar linkage when the handle (in blue) and the connecting link (in green) are collinear. The jaws can be opened by lifting the handle. 

The clamping thickness (the opening of the jaws at the toggle position) can be adjusted by the screw at the end of the base. As the screw moves the fixed pivot of the connecting link, the characteristics of the fourbar linkage are changed, and the toggle position will be changed with the screw adjustment. 

In the simulation file, the jaw opening can be adjusted.  

Source

This Working Model file is adapted from Figure P6-21 on p. 320 in Design of Machinery, 3rd ed. by Norton, R.L., McGraw-Hill, 2004.

It is also from Figure P1.5 on p.42 in Mechanism Design: Analysis and Synthesis, 3rd ed. by Erdman, A.G. and Sandor, G.N., Prentice Hall, 1996, from Figure 7-124 on p.319 in  in Engineering Mechanics- Statics 2nd ed.,  by  Riley, W.F. and Sturges, L.D., John Wiley & Sons, 1993, and from Figure P4.200 on p. 257 in  Engineering Mechanics, Statics, 3rd ed. by McGill, D.J., and King, W.W.,  PWS Publishing Company, 1995..

Credits

This Working Model file was first developed by Fan (Michael) Mo. Photos were also taken by Shih-Liang (Sid) Wang.