CUTTING BIT FOR MINING AND ROAD-BUILDING MACHINES Russian patent published in 1997 - IPC

FIELD: mining and construction. SUBSTANCE: the cutting bit has holder, working head with axial protrusion, end-piece of hard-alloy material and device for fixing the distance between end-piece and working head in formation of soldered joint between them. Axial protrusion forms ring-shaped thrust face on the front end of working head. End-piece includes working part in form of body of revolution and base with supporting surface and with socket for accommodation of axial protrusion. Device for fixing distance between end-piece and working head is made in form of supporting protrusion on the end of axial protrusion of working head and hollow located on the bottom of end-piece socket and accommodates supporting protrusion. Supporting protrusion and hollow walls are of shape of cones of revolution. Axes of cones governing shapes of supporting protrusion and hollow are located on the longitudinal axis of cutting bit. Value of angle of inclination of cone generator which governs the shape of supporting protrusion equals not less than 0.95 and not in excess of 0.99 of the value of inclination angle of cone generator which governs the shape of hollow walls. EFFECT: higher efficiency. 21 cl, 7 dwg