ball-and-socket joint

ball-and-socket joint, in engineering, mechanical connection used between parts that must be allowed some relative angular motion in nearly all directions. As the name implies, the joint consists essentially of a spherical knob at the end of a shaft, with the knob fitting securely into a mating socket. Like other mechanical joints, a ball-and-socket joint must have some provision for lubrication and is normally provided with a seal to prevent loss of the lubricant. Joints of this type are commonly used in mounting the front wheels of automobiles, allowing these wheels movement sufficient for steering. In this application they are usually called ball joints.

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ball-and-socket joint, ball joint

1. a coupling between two rods, tubes, etc., that consists of a spherical part fitting into a spherical socket, allowing free movement within a specific conical volume

2. Anatomy a bony joint, such as the hip joint, in which a rounded head fits into a rounded cavity, allowing a wide range of movement

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ball-and-socket joint [¦bȯl ən ′säk·ət ‚jȯint]

(anatomy)

enarthrosis

(geology)

cup-and-ball joint

(mechanical engineering)

A joint in which a member ending in a ball is joined to a member ending in a socket so that relative movement is permitted within a certain angle in all planes passing through a line. Also known as ball joint.