Mechanisms with Lower Pairs - Theory of Machines - Chapter Contents

What is a lower pair?
If a pair has a surface contact between the two elements while in motion, it a called lower pair. sliding and turning pairs are lower pairs.

Pantograph

It is mechanism used to create straight line motion that is used to enlarge or reduce movements given at the input side.

Peaucellier's Mechanism

http://me.lsu.edu/~ram/TEACHING/kinematics/Peaucellier.pdf

Hart Straight Line Mechanism


Kempe's Mechansim

Scott Russel Mechanism

Watt Straight Line Mechanism

Modified Scott Russel Mechanism

Grass Hopper Mechansim

Tchebicheff Straight line mechanism

Robert's straight line mechanism

Straight Line Mechanisms used in Engine Indicators

Simplex indicator

Crosby indicator mechanism

Thomson indicator mechanism

Dobbie McInnes indicator mechanism