GB1017376A - Improvements in or relating to rock anchors - Google Patents

Abstract

1,017,376. Anchor-bolts; nuts. HAYDEN-NILOS Ltd. Dec. 11, 1964 [Dec. 14, 1963], No. 49474/63. Heading F2H. A rock anchor with a bearing plate 12, e.g. for holding a rock-supporting plank, comprises a rod 3 moved axially in a tube 4 by a halved nut 19, 19 co-acting with a threaded portion 3A of the rod to expand a bore-gripping arrangement 1 at the inner end of the anchor, each nut-half 19 moving in a radial guideway formed by opposed grooves 18 of two parallel channel-shaped members 17 and each nuthalf having a slotted extension 20 to which a quick-release lever 23, pivoted on the member 17, is connected by a link 21. When the levers 23 and links 21 are aligned with the guide members 17, as shown in Fig. 2, the levers are used by means of handles 30 or knobs at the lever ends, to rotate the nut 19, 19 to draw out the rod 3 and expand the sleeve 1 (or an equivalent in the form of serrated shells) to anchor the device. For release of the anchor, from a distance to avoid rock fall, a rope is passed through the angles 33 between extensions 32 of the handle stems and the levers (or through eyes provided on the levers) and the levers are pulled to the position shown in Fig. 4 to draw the nut-halves 19 apart. The guide members 17 between which the levers and links are pivoted are welded to a sleeve 16 rotatable on the rod 3 but loosely secured to the bearing plate 12 (welded to the tube 4) by a collar 14 on the plate. A transverse pin 10 on the rod 3 slides in slots 9 in the tube 4. Nuts 2, 31 are secured by pinning and welding respectively to the rod ends. The screw-thread of the nut and rod is of buttress, square or acme form.