| 摘要 |
A blind fastener assembly includes a pin, an expander and a sleeve. The pin and expander may include, in one configuration, mating threads for drawing the sleeve axially over the expander toward the blind side of a workpiece, or the pin may be a pull-type wherein the portion of the pin opposite from the blind side end has pull grooves which are adapted to be gripped by a conventional pull gun. The sleeve is a tubular member having a portion of varying radial wall thickness between the ends thereof. The expander extends through aligned holes in the workpieces and has a tapered nose surface proximate the reduced thickness portion of the sleeve. When an axial force is exerted on the pin, the sleeve is forced over the tapered nose surface on the expander toward the blind side of the workpiece and is expanded in diameter. When the leading edge of the sleeve contacts the blindside workpiece surface, a radially outwardly extending bulb forms at the varying thickness portion in order to accommodate variations in the thickness of the workpieces. The diameter of the bulb is dependent on the overall joint thickness, with a larger diameter bulb forming for a maximum joint thickness and a smaller diameter bulb being formed for a minimum joint thickness. At a predetermined axial position of the pin relative to the expander, a reduced diameter breakneck portion of the pin fractures at a predetermined torque or load, leaving a properly tensioned joint.
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