摘要 |
To prevent movement of an article along a shaft or a bore, an element engages the article and engages the shaft or bore at locations forming an angle no greater than tan-1 mu . The locations of engagement lie in a first plane extending perpendicular to a second plane in which lies the axis of the bore or shaft. A third plane extends perpendicular to the axis. The angle is between the first and third planes. mu is the coefficient of friction between the element and the bore or shaft. |