Patent GB-938904-A (GB)
Title: Improvements relating to cutter sharpening machines
IPC: B23Q16/06
Filed: 1961-10-03
Abstract: 938,904. Sharpening cutters. GLEASON WORKS. Oct. 3, 1961 [Oct. 18, 1960], No. 35663/61. Class 60. A cutter sharpening machine comprises a frame, a cutter spindle supported on the frame, a grinding wheel and means supporting it for movement upon the frame for traversing the sharpening face of a cutter on the spindle, adjusting means whereby relative adjustment in a plurality of directions may be effected between the cutter spindle and the wheel supporting means to bring them to a first positional relationship wherein a first surface may be ground on the sharpening face, and a shifting mechanism for effecting relative back and forth motions in a plurality of directions between the spindle and the wheel supporting means, including angular motion of the spindle about its axis, to shift them back and forth between said first positional relationship and a second positional relationship wherein a second surface may be ground on the sharpening face. General.-A machine comprises a frame 30 on which a frusto-conical grinding wheel W is mounted for reciprocation longitudinally of the frame (arrow 31) to cause its conical face 32 to traverse the face 33 of a blade of a cutter C also supported by the frame. The mounting for the wheel includes a slide 34 adjustable longitudinally on the frame along T-slotted ways 35. A column 36 is adjustable on the slide laterally of the frame (arrow 37). Movable vertically on the column (arrow 38) is a bracket 39 on which a wheel head support 41 is mounted for reciprocation (arrow 31) and for angular adjustment and feed motion about axis 42. A wheel head 43 is adjustable on support 41 in a direction perpendicular to axis 42 and to wheel rotation axis 44 (arrows 45). A motor 40 carried by head 43 drives the grinding wheel spindle through an endless belt. A cutter head bracket 46 is mounted on the frame, beneath the grinding wheel, for angular adjustment about transverse axis 47. To the bracket a cutter head 48 is pivotally adjustable about axis 49 perpendicular to axis 47. A housing 51, for the spindle which supports the cutter C to be sharpened, is adjustable in the head 48 in the direction of the spindle axis 53 and angularly about that axis. The machine is adapted to sharpen either right or left hand cutters by mounting the grinding wheel either in the position W or the position W<SP>1</SP> and by adjusting the wheel head 43 and support 41 about axis 42 so that the wheel axis is in position 44 or 44<SP>1</SP>. The conical face 32 of the wheel traverses sharpening plane 54 or 54<SP>1</SP> as the wheel reciprocates, these planes being parallel to axis 42. In both cases the periphery of the wheel traverses a plane 55 perpendicular to planes 54, 54<SP>1</SP> and parallel to axis 42. The machine is adapted to sharpen either a face mill cutter C or a disc mill cutter C<SP>1</SP> by adjusting the cutter head 48 and bracket 46, usually through 90 degrees, to bring the cutter spindle axis into either the perpendicular relation 53 or the parallel relation 53<SP>1</SP> to the axis 42. Cutters of the same design are preferably always sharpened with the plane containing the tips of the blades in the same position relative to the machine frame. To accommodate changes in the cutter tip plane resulting from repeated sharpening back of the cutters, which usually are relieved radially in the case of disc mills and axially in the case of face mills, the spindle housing 51 is adjusted along axis 53 in head 48. Thus in the case of a face mill cutter of any one particular design, the tip plane of the cutter will always be brought to the same plane perpendicular to the cutter spindle axis, i.e. to the same distance from axis 49. The adjustment is preferably made with the aid of a gauge adapted to rest on the cutter head 48 and touch the tip of a cutter blade. Due to this adjustment the other machine settings, except that to compensate for changes in the grinding wheel diameter, may be pre-calculated. Adjustment (arrow 38) of the bracket 39 upon column 36 is employed to bring the periphery of the wheel into tangency with the plane 55. The bracket is retracted to different positions to (a) withdraw the wheel to permit blade-to-blade indexing of the cutter and (b) position the wheel for dressing and also for providing clearance for mounting and removing of the cutter. The vertical position to which plane 55 is adjusted depends upon the position and height of the face 33 of the cutter, when the latter is in sharpening position, and is conveniently made after the cutter has been mounted and adjusted on the machine, preferably with the aid of a gauge applied between the cutter blade and the tip of the wheel W when the latter has been raised to indexing position. The sharpening offset adjustment of face mill cutters and the sharpening angle of disc mill cutters are established by adjustment of sharpening plane 54 or 54<SP>1</SP> in a direction perpendicular thereto by adjustment (arrow 37) of the column. The sharpening angle of a face mill cutter and the sharpening offset adjustment of a disc mill cutter are established by tilting the cutter axis 53 relative to the sharpening plane 54 or 54<SP>1</SP> by adjusting the cutter head 48 about axis 49. Feed motion of the wheel, to grind successive layers of stock from the cutter blade on successive wheel passes is by pivotal motion of the wheel head 43 and support 41 about axis 42 and is concluded when the conical surface of the wheel reaches the sharpening plane. Adjustment of the cutter spindle housing 51 in head 48 angularly about axis 53 enables the faces 33 of the cuter to be brought to the sharpening plane 54 or 54<SP>1</SP>. Reciprocation of wheel W relative to bracket 39 (arrow 31).-Wheel head support 41 is affixed to a shaft 61 journalled, on axis 42, in ball sleeve bearings in bracket 39. Reciprocation is effected by a motor, preferably of adjustable speed, driving through reduction gearing a crank shaft 65 on whose crank pin are coaxial rollers 66, 67 acting to reciprocate vertically an assembly comprising a slide 68 and a diametrically slotted disc 71. A block 72 slidable in the slot of the disc is pivoted, on axis 73, to a lever 74 pivoted, on axis 75, to bracket 39. The opposite end of the lever has a slot in which is slidable a block 76 pivoted, on axis 77, to a second lever 78 pivoted, on axis 79, on bracket 39. Lever 78 carries a roller 80 engaging a transverse slot 81 in shaft 61. Thus up and down motion of slotted disc 71 causes the levers to swing about the axes 75, 79 and reciprocate the shaft 61 right and left. The length of stroke is adjusted from zero to a maximum by changing the inclination of the slot of disc 71 by turning it on slide 68 about its axis 82. To effect this a tubular piston 83 in a cylinder 84 in the slide has rack teeth 85 meshing with a segmental pinion 86 secured to the disc. The lower end of a piston rod 87 slidable in the piston 83 is engageable with roller 67, the roller 66 being enagageable with a shoe 88 on slide 68. The upper end of piston rod 87 is engageable with a shaft 89 journalled in bracket 39 and having a bevel gear 90 meshing a pinion 91 rotatable manually by a wrench. A nut 92 screwthreaded on the upper end of piston 83 is splined to shaft 89. In the extreme left-hand position of the shaft 61, which is the cutterloading and dressing position, the end of the shaft is against a stop 93 on bracket 39. In this position the slide 68 is entirely free of the rollers 66, 67 this condition being achieved by supplying hydraulic pressure to the lower end of cylinder 84 to raise the piston 83 and rotate pinion 86 until its shoulder 96 abuts face 97 of slide 68 thereby turning the slot of disc 71 to its maximum inclination from the vertical. The pressure simultaneously acts between slide 68 and piston rod 87 to cause the piston rod to abut shaft 89 and slide 68 to be moved downwardly to its limit position wherein the parts 71, 74, 78 have moved the shaft 61 against abutment 93. In normal operating condition, hydraulic pressure is supplied to the upper end of cylinder 84. This urges piston rod 87 downwardly to its lower limit position in slide 68 wherein the rollers 66, 67 are confined between the lower end of the-rod and shoe 88, and urges piston 83 downwardly until nut 92 abuts the head 102 of cylinder 84. The length of this stroke, which is adjustable by turning pinion 91, determines the inclination of the slot in disc 71 and hence the stroke of wheel W. Feed motion of wheel W about axis 42.-The mechanism includes face cams 111, 112, respectively employed for right hand and left hand cutters, the concave surface of cam 111 being engageable by roller 113 and the convex surface of cam 112 being engageable by roller 114. The cams are shiftable as a unit axially on their drive shaft 115 by roller 116 or lever 117 operated through link 118 by hand lever 119. The rollers 113, 114 are mounted on rod 121 reciprocable axially on bearings in bracket 39. A support 122 pivoted to the rod for reciprocation therewith carries a guide roller 123 engageable in a guide slot 124 or 125 (according to whether the cutter is of right or left hand) in an arm 126 fixed to shaft 61. A spring-backed plunger 127 urges support 122 to a limit position determined by abutment 128 wherein the roller 123 is engaged in the slot. A face 130 of arm 126 is engaged by a roller 129 on a lever 131 urged about its pivot 132 by a spring 133 to maintain roller 113 against cam 111. A similar device acts against face 130A of arm 126 when roller 123 is engaged in slot 125 to maintain roller 114 against cam 112. The feed cam assembly 111, 112 is oscillated by an adjustablespeed reversing motor and reduction gearing connected to shaft 115, causing alternate infeed and return motions of the shaft 61, and of wheel W carried by it, as the stroking motion of the wheel proceeds. The angle of oscillation is determined by motor reversi