BLIND FASTENER WITH LOCK GROOVE

摘要

A blind fastener including a pin and a sleeve and having grip compensating means for accommodating workpieces varying in total thickness and having means for expanding the sleeve for filling the clearance between the fastener and associated openings in the workpieces and at the same time providing material from the sleeve in the area of expansion to define a lock between the pin and the sleeve. The grip compensating means is separate from the pin and is generally tubular in construction with a portion adapted to provide radial deformation. The construction is such that the pin will travel the same amount regardless of whether the fastener is used in the minimum grip or maximum grip condition. The fastener provides hole fill over an extended portion of its grip. The excess of the material of the sleeve that is used to provide hole fill is used to provide the material for the internal lock between the pin and sleeve. The lock material is provided for at least between one-third to around one-half of the pin travel, i.e. the distance over which the pin extruding land engages the reduced diameter hole filling sleeve bore. This permits the use of a substantially wide lock groove. The fact that the groove is wide results in an increase in effective shear area enhancing the lock between pin and sleeve. The extruding land on the pin does not act as a stop and movement of the pin is arrested by an external means such as engagement of a tool with the leading face of the guide land on the pin.