摘要 |
<p>A cylindrical expansion sleeve of metal for an anchorage device has a plurality of circumferentially spaced apertures (22) intermediate its ends, and a plurality of slits (18) each extending longitudinally from one of its ends to a respective one of said apertures (22). Each aperture (22) has a major dimension (L) and a minor dimension (W) at right angles to the major dimension (L), with the major dimension (L) extending at an acute angle preferably of between about 20o and 45o to an axial plane of the sleeve. The inclined arrangement of the apertures permit restricted collapse of the sleeve at a predetermined loading. </p> |