Double cardan universal joint

摘要

An improvement in a double Cardan universal joint having a pair of spiders connected by a ring-shaped coupling member, a pair of yoke members angularly movably connected with each other by the spiders, a centering assembly for aligning the yoke members with each other and defining a reservoir for grease within a bridge forming a part of one of the yoke members and a breather hole formed in the bridge for making the reservoir communicate with the atmosphere. The improvement comprises a valve of elastic material inserted in the breather hole and capable of elastically blockading the communication of the reservoir with the atmosphere when internal pressure of the reservoir is below a predetermined amount and being elastically deformed to make the reservoir communicate with the atmosphere when the internal pressure reaches or exceeds the predetermined amount.