This linkage also appears in auto suspensions to stop side-to-aspect movement of the human body relative to the wheels. Also see the short article Parallel motion. idle pulley, idle wheel, idler pulley a pulley with a shaft that presses versus a guide belt to guideline or tighten it [forty six] https://zandereaunf.answerblogs.com/13751075/detailed-notes-on-machine-definition