Image Number 7 for United States Patent #6554554.
A threaded fastener arranged to engage with a threaded shaft and tighten an object to the shaft by stretching the threaded shaft approximately parallel to its own axis. The threaded fastener is arranged so that when screwed on to the shaft the contacting surface are not parallel, thereby leaving a gap. The threaded fastener further comprises a tilting means of levering the surfaces away from one another and enlarging the gap between the surfaces. The tilting means may comprise an additional threaded shaft being threaded into an additional threaded aperture in the fastener or a ball bearing located in a groove on the surface of the fastened and contacting the surface of the object. The tilting means stretches the threaded shaft without bending the bolt requiring far less torque for stretching than a conventional nut and bolt tightened with a wrench.