GB1375892A - - Google Patents

Abstract

1375892 Tool holders for percussive drills HILTI AG 11 May 1972 [12 July 1971] 22091/72 Heading B4C An adaptor attachable to one end of a threaded anchor bolt or rod 18 comprises a shank 1 receivable in a tool holder of a rotary percussive tool for rotation therewith and provided with a surface 7 to which axial impacts are applied, and an element 2 which is a releasable push fit on a spigot 8 of the shank and is non-rotatable relative thereto. The element has a screw-threaded bore 19 for receiving one end of the bolt or rod. As illustrated, a bolt 3 limits the amount by which rod 18 can be screwed into bore 19 is urged to the position of Fig. 1, by a spring 4. A pin 37 engaging a surface 38 or the head 22 defines this position. Insertion of an appropriate tool in hexagonal socket 24 in the bolt's head and rotation of the bolt against bias of spring 4 and through angle x will bring flat 23 on the bolt's shank 21 into register with the end of the rod 18 so as to permit easier removal of the latter from the element. Axial movement of the bolt is prevented by the bolt's head and by spring ring 29, although the latter may be omitted if the spring 4 is of a suitable design. In operation the anchor bolt or rod is forced into a bore hole containing a cartridge of adhesive material components, so as to rupture the cartridge and mix the adhesive components. In an alternative arrangement the bolt is movable axially to release the threaded rod or bolt.