Patent GB-466512-A (GB)
Title: Improvements in or relating to mining machine cutter chains and links therefor and to the manufacture thereof
IPC: E21C35/19
Filed: 1935-11-29
Abstract: 466,512. Making cutting-chains. HOY, A. Y., and PHILP, J. I. Nov. 29, 1935, No. 33196. [Class 83 (ii)] The pick boxes or connector links for mining- machine cutting-chains, of the type wherein the pick boxes, connected by single connector links, comprise a pair of side plates and a bridge or pick boss, are formed from rolled steel bars without recourse to forging. Side plates 16, 17, Fig. 3, are cut from rolled bars formed with ribs 5, 6, and holes 9 for the pivot pins are drilled and reamered therein. The lower ribs are turned to form surfaces 10, 11, and windows 12, 13 are formed by drilling, slotting, or milling to permit the escape of dust, and to enable a pick to be dislodged. The corners 14 are then milled off, and keyways 15 are milled on the inner surfaces to intersect the holes 9, these keyways being engaged by lugs 41 on the pivot bushings 36 to prevent rotation. The top edges may be milled to provide a clearance for the weld. The holes 9 may be used as locating means during subsequent working operations. Two pick boxes are formed by severing a length 18 cut from a rolled bar having two longitudinally extending curved faces 20 and two flat faces 19. The section may be divided on a plane 25 perpendicular or, as in Fig. 3, inclined to the faces 19 at any angle. Set screw holes 22 are drilled preferably before parting the length, and pick sockets 23 are formed in one operation before parting by drilling and broaching, flat surfaces 24 being milled on the surfaces 20 to avoid stresses on the broaching tool. A welding clearance 26 is milled on the boss, and after hardening and tempering the parts are assembled in a jig and welded. In the production of a double box to carry two picks, two boss sections are cut from a section 18, and are recessed to interengage, the recesses extending to the sockets 23, Fig. 10. The recesses are formed before parting the section on the line 25 by forming a slot between the lines 31, Fig. 2, and extending to the dotted lines. Connector links are made by cutting off lengths 33 from a rolled steel bar, drilling and reamering holes 35 for the reception of the pivot bushings 36, and profiling the ends 38 by milling. A slot 39 is milled in the upper edge to receive a stop-piece 34, also cut from rolled bar, and after hardening and tempering the parts are welded together. The processes may be modified by performing some or all of the machining operations, after assembly or welding. The holes in the side plates may be drilled before cutting them from the original bar. A bridge for a double box may be produced from a single section cut from a rolled bar, the cut faces forming either the side or end faces in the finished bridge. A piece on each side may replace the stops 34, or these may be dispensed with. Tongues in one part engaging grooves in the other may strengthen the bridge construction. Flanges on the side plates, or on the bridge, may extend so as to form part of the other member. Specification 391,901, [Group XXI], is referred to.