Four-bar linkage
The simplest closed-loop linkage, made of four rigid bars connected in a loop with one bar fixed to the frame. Depending on the relative lengths of the four bars, it can trace a wide range of output curves, including approximate straight lines, closed loops, and dwell motions, from a single rotary input, and it is the basic building block that more complex linkages, such as the Jansen linkage, chain together in multiple stages.
Defined in 2 GAGE programs, which carry 2 distinct definitions of it. The wording above is taught in Engineering Judgment and Professional Formation.
How each discipline defines it
The same term does different work depending on who is using it. These are the definitions as each program teaches them, unedited.
The simplest closed-loop linkage, made of four rigid bars connected in a loop with one bar fixed to the frame. Depending on the relative lengths of the four bars, it can trace a wide range of output curves, including approximate straight lines, closed loops, and dwell motions, from a single rotary input, and it is the basic building block that more complex linkages, such as the Jansen linkage, chain together in multiple stages.
A closed kinematic loop consisting of four rigid links connected by four revolute joints. One link is fixed (the ground link), one is driven by the motor (the crank or input link), one receives the output motion (the rocker or output link), and the fourth (the coupler) connects input and output. By choosing the four link lengths, the designer chooses the output motion.
Terms it appears with
Not an alphabetical neighbourhood: these are the terms taught in the same lessons, ranked by how often they appear together.