Definition - What does Knuckle Joint mean?
Knuckle Joint, also known as a mechanical joint, is an articulation formed when two rods are joined together with comprehensive forces in which the projection of one fits into the other. A Knuckle Joint is made when there is a requirement for angular moment or flexibility. It allows different sections of logging string to turn from centralized to decentralized to ensure all the sensors have the optimal positions in the wellbore. It is designed in such a way that different parts of a tool string are fully decentralized in different tubing sizes.
Petropedia explains Knuckle Joint
A Knuckle Joint is formed when two rods are connected under a tensile load. During its formation, there is always an axial line of action of load. The major components of the joint are a single eye, knuckle pin and double eye. It can be used in many ways, for example, as a rod joint of roof truss and as a link of roller chain. It is also used in tractors at times. It provides superior strength hence it is used as a decentralized tool for better sensor response. A major advantage of the Knuckle Joint is that it is easy to implement and maintain.