Linkage (mechanical)

[1] The connections between links are modeled as providing ideal movement, pure rotation or sliding for example, and are called joints.

A linkage modeled as a network of rigid links and ideal joints is called a kinematic chain.

B. Kempe, who showed that linkages for addition and multiplication could be assembled into a system that traced a given algebraic curve.

[6] Kempe's design procedure has inspired research at the intersection of geometry and computer science.

Within two decades these computer techniques were integral to the analysis of complex machine systems[10][11] and the control of robot manipulators.

[12] R. E. Kaufman[13][14] combined the computer's ability to rapidly compute the roots of polynomial equations with a graphical user interface to unite Freudenstein's techniques with the geometrical methods of Reuleaux and Burmester and form KINSYN, an interactive computer graphics system for linkage design The modern study of linkages includes the analysis and design of articulated systems that appear in robots, machine tools, and cable driven and tensegrity systems.

The number of input parameters is called the mobility, or degree of freedom, of the linkage system.

A system of n rigid bodies moving in space has 6n degrees of freedom measured relative to a fixed frame.

This is a sequence of rigid body transformation along a serial chain within the linkage that locates a floating link relative to the ground frame.

Each serial chain within the linkage that connects this floating link to ground provides a set of equations that must be satisfied by the configuration parameters of the system.

Linkages can be found in joints, such as the knee of tetrapods, the hock of sheep, and the cranial mechanism of birds and reptiles.

For suction feeding a system of linked four-bar linkages is responsible for the coordinated opening of the mouth and 3-D expansion of the buccal cavity.

Linkages are also present as locking mechanisms, such as in the knee of the horse, which enables the animal to sleep standing, without active muscle contraction.

In pivot feeding, used by certain bony fishes, a four-bar linkage at first locks the head in a ventrally bent position by the alignment of two bars.

The release of the locking mechanism jets the head up and moves the mouth toward the prey within 5–10 ms.