摘要 |
A fastener tensioning system for use with torque producing power tools, such as, nut runners or the like. The system includes apparatus to rotate the fastener and determine when the fastener has been driven to its yield point in tension, and, thereafter, the fastener is backed out a precise amount of rotation to establish a level of tension in the fastener below the yield point. The method of this invention improves upon the conventional turn-of-the-nut method for fastener tensioning; in that, the precise fastener rotation is started from a relatively well-known and well-defined point as opposed to a arbitrary predetermined low level of torque. In addition, the method assures by inspection the proper condition of the bolt and thread prior to making the final tensioning step.
|