GB815631A - Sawing chain for mechanically-actuated chain saws for the cutting of hard stone - Google Patents

Abstract

815,631. Sawing stone. STIHL, A. Oct. 23, 1956 [Oct. 24, 1955, Dec. 31, 1955; June 21, 1956], No. 32197/56. Class 124. In a sawing chain for a mechanically driven portable chain saw for hard stone, including pivotally connected flat links 1 some or all of which carry cutting elements 6 operating by grinding on the outer edge and some or all of which have means, e.g. a carrier dog 2, on the inner edge for engagement with the driving wheels the elements 6 have their working surface convex perpendicularly to the plane of the saw, and have no sharp edges. The elements 6 may be round in cross-section and arranged on a bolt 5 lying in the cutting direction and may rotate thereon. The axes of the elements may be inclined to the horizontal and so the elements may lie slightly eccentric to the cutting axis. The chain may have depth-limiters between some or all of the links 1 with a work-contacting surface 25 on a vertical member 24. Fig. 10. 0À2 mm. lower than the member 6, Fig. 1. Several cutting elements with separating flange lugs may be mounted on each link which may be arranged to correspond to the curvature of the guide roller or a curved guide. In one suitable arrangement of links there is a repeated sequence of a link having two elements with eccentricity to the right, a link having a single element without eccentricity, a link having two elements with eccentricity to the left and a link having a single element without eccentricity. In a modified form the links have a flange 36, Figs. 15 and 17, carrying the cutting element 37, have gaps or recesses 40 in their working surface to receive the stone dust and their sides are vertical or partly tapered and the elements extend to or beyond the sides and partially embrace them. Each link 35 comprises a carrier dog 46 on the body portion 41, the flange part 36 and rings 42 with openings 47 to take hollow rivets 34, the links being joined by intermediate link 48, Fig. 14, The dogs 46 slide in a groove 45 carried by a guide rail 43 having channels 44 for the supply of cooling and rinsing water introduced through a tube 54 Fig. 19. In use the chain may be driven by an electric motor or a petrol engine in a motor block 49 on which are handles 50 (having a switch 56), 51, from an outside wheel 52 on the case 53 over a guide roller 55, Fig. 19, or guide arc, Fig. 14. The chain is formed symmetrically and is usable in both cutting directions. The upper surface of a cutting element may have straight portions operative whilst moving in a straight path and curved portions whilst moving in a curved path. The cutting elements may include chippings or grains of diamond or a very hard carbide which may be embedded in metal or plastic material or a like hard body may be embedded.