Patent GB-713610-A (GB)
Title: Semi-automatic rotary cable drill dresser
Inventor: IVES MILO WARREN
IPC: B21K5/06
Filed: 1952-09-30
Abstract: 713,610. Making rock drills. IVES & WATERS, Inc. Sept. 30, 1952, No. 24450/52. Classes 83 (2) and 83 (4) Rolling.-Apparatus for sharpening rock drills comprises means for holding the drill bit stationary while a rotary forming die mounted adjacent said holding means is brought into oscillatory contact with an adjacent end of said bit to reshape it. Mounted on a supporting plate 3' carried by beams 1 are bearings 3 of a powerdriven transverse shaft 4. A pinion 7 on the shaft 4 meshes with a gear 8 and rotates a crankshaft 9 also mounted on bearings on the plate 3<SP>1</SP>. The crank arms 11 have a number of openings 13 for positioning crank pins 12 for adjusting the throw of levers 14 each of which has an elongated slot 15 through which the crank pin extends said levers being pivoted on a shaft 16. Vertically disposed arcuate racks 22 are supported on the plate 3<SP>1</SP> in spaced plates 18 by means of upper and lower rack supporting bars 20 and 19 respectively the upper bar being adjustable in the plates 18 by means of arcuate slots 21. The front ends of the levers 14 have inwardly extending spacer sleeves 23, Fig. 3, and keyed to the sleeves are the ends of a shaft 24 which carries a rotary forming die or roller 25, rotatable on the shaft. The forming die may be pinned to the shaft if desired. The roller 25 has gear teeth 28 which mesh with the racks 22 so that when the levers 14 raise the roller it will be rotated counter clockwise, Fig. 2, and vice versa. Intermediate its ends, the roller 25 has a V-shaped annular groove 29 with convexed side walls one half of said walls being smooth as at 30, Fig. 4, the other half being provided with opposite'y curved scraping ribs 31 and 32. A drill bit 33 to be sharpened is formed with longitudinal oppositely disposed water courses 34 and at its cutting end with a diametrically disposed penetrating edge 35 shaped complimentary to the annular groove 29 and concaved longitudinally and has sharpened end portions 36. During sharpening the bit is heated and clamped between a pair of dies 37 mounted upon a plate 38 slidably adjustable on the frame 1. The upper die 37 is adjustably secured to a cross head 40 to enable bits of different diameter to be clamped. The front faces of the dies 37 are formed with sharp ribs 44 aligned with the penetrating edge 35 of the bit and provide abutments for the ends of the edge 35. The back portion of the bit is supported in an adjustable saddle 45 and the bit is urged forwardly by means of a member 50 the base of which has teeth 52 engaging in' toothed racks 53 on the frame 1. A hand crank 48 forces the penetrating edge of the bit into the groove 29 and against the surface of the roller 25. The apparatus is then set in motion and rotation of the crank pins 12 rock the arms 14 vertically which oscillate the roller 25 upwardly and downwardly over the penetrating edge and crushing face of the bit and the ribs 32 cause the malleable metal of the heated edge to be upset against the ribs 44 of the clamping dies 37 to rerorm the concave penetrating edge and its sharpened ends 36. At the end of the reshaping operation the roller is rotated on its shaft and the racks re-engaged so that the smooth surface of the roller is presented to the penetrating edge. Alternatively the racks can be disengaged from the roller and the roller rotated by the penetrating edge 35. Also, the roller may be pinned to its shaft 24 and the racks disengaged whereon the stationary roller wipes the face of the penetrating edge with an abrasive action. The vertical travel of the roller is adjusted by locating the crank pin 12 in a selected opening 13 in the crank web. Alternatively the pivot 16 of the rocker arms 14 may be adjustable. The plate 3' and the parts supported thereon are forced against the face of the bit by means of a hydraulic ram 55 in a cylinder 56.