US3086508A

US3086508A - Grinding machine and wheel dresser therefor

Info

Publication number: US3086508A
Application number: US168000A
Authority: US
Inventors: Leonard O Carlsen; Thomas A Deprez
Original assignee: Gleason Works
Current assignee: Gleason Works
Priority date: 1960-10-18
Filing date: 1962-01-09
Publication date: 1963-04-23
Anticipated expiration: 1980-04-23

Description

April 1963 o. CARLSEN ETAL 3,086,508

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed 001:. 18, 1960 4 Sheets-Sheet 1 FIG. I

INVENTORS LEONARD 0-. CARLSEN y THOMAS A. DEPREZ ATTORNEY April 3, 1963 L. o. CAYRLSEN ETAL 3,086,508

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed Oct. 18, 1960 4 Sheets-Sheet 2 FIG. 2

M5 T W! I g2 u Hm! 40 II I ul 38 4 I l 44..

'H"" r M8 8 April 1963 1.. o. CARLSEN ETAL 3,086,508-

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed Oct; 18', 1960 4 Sheets-Sheet 3 FIG. 5 am April 1963 L. o. CARLSEN ETAL 3,086,508

GRINDING MACHINE AND WHEEL DRESSER THEREFOR Original Filed Oct. 18, 1960 4 Sheets-Sheet 4 .FIG. 6

FIG. 7

2 & on 7 241 no: 7A-25o 2' F|G.8 I f 2 5a- 2 4 243 234 23s in. W 232 253 I United States Patent Ofiice 3,086,508 Patented Apr. 23, 1963 11 Claims. (Cl. 12511) The present invention relates to a cutter sharpening machine or like machine employing a grinding wheel and a wheel dresser therefor, and is a division of our copending application Serial No. 63,414, filed October 18,1960.

A machine according to the invention has a grinding wheel with a conical face, a dresser wheel whose axis is approximately parallel to a cone element of said conical face, said dresser wheel having a cylindrical surface for dressing said conical face and a surface of decreasing radius and concave profile for dressing an edge radius on the grinding wheel, means for guiding the dresser wheel for motion (a) in a radial direction toward and away from said cone element to dress said edge radius with said surface to concave profile and return, and for motion (b) approximately in the direction of the axis of the dresser wheel to dress said conical face with said cylindrical surface.

In the preferred embodiment of the invention shown in the accompanying drawings:

FIGS. 1 and 2 are respectively side and front views of the machine;

FIG. 3 is a section in plane 3'3 of FIG. 4;

FIGS. 4 and 5 are vertical sections respectively in planes 4--4 and 5-5 of FIG. -1;

FIG. 6 is a front view of the wheel dresser mechanism, parts of which appear on a smaller scale in FIGS. 1 and 2;

FIGS. 7 and 8 are sectional views taken respectively in planes 77 and 88 of FIG. 6.

Referring to FIGS. 1 and 2, the machine comprises a frame 30 on which a grinding wheel W is mounted for reciprocation longitudinally, as indicated by arrow 31, to cause its conical face 32 to traverse sharpening plane 33 of a cutter C to be sharpened, which is also supported by the frame. The mounting of the wheel includes a column 36 adjustable laterally of the frame, as indicated by arrow 37, and a bracket 39 movable vertically on the column, as indicated by arrow 38. A wheel head 43 .is adjustable as indicated by arrow 45 in a direction perpendicular to both axis 42 and the wheel rotation axis, designated 44. The wheel is driven by motor 40 carried by the head 43.

A cutter head bracket 46 is mounted on the frame, beneath the grinding wheel, for adjustment about transverse axis 47. On this bracket a cutter head 48 is pivotally adjustable about an axis 49 which is perpendicular to axis 47. A housing 51, for spindle 52 which supports the cutter C, is adjustable in the head 48 in the direction of the spindle axis 53 and also 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 shown at W in full lines or at W in broken lines in FIG. 2, and by adjusting the wheel head and support, 43, 41, about axis 42 so that the wheel axis is in

position

44 or 44. In these respective positions the conical face 32 of the wheel traverses sharpening planes 54 and 54' as the wheel strokes back and forth in direction 31, these planes being parallel to axis 42. In both cases the periphery of the wheel traverses a two nuts to urge them apart.

plane, designated 55, which is perpendicular to

planes

54, 5 4 and parallel to axis 42.

FIGS. 3 and 4 show the mechanism by which the wheel feed and return motions 45, FIG. 2, are accomplished. In the wheel head 43 is journaled the spindle 171 on either end of which the wheel W may be mounted. The wheel head is supported on ball-sleeve bearing 172 for motion in wheel head support 41 in direction 45, perpendicular to axis 44 of the spindle. Prior to each wheel dressing operation a ratchet mechanism is operated to lower the wheel in direction 45 by a predetermined distance. This ratchet mechanism comprises a piston 173 movable in one direction in a cylinder in the wheel head support by hydraulic pressure applied to cylinder chamber 174, and in the return direction by a spring 175 when this pressure is released. A pawl 176 pivoted at 177 to the piston is urged by a spring 178 into engagement with a ratchet wheel 179. Upon return motion the pawl engages a stud 181 and is thereby pivoted out of engagement with the wheel 17-9. The latter has secured thereto a nut 182 which is threaded onto a screw 183 secured to the wheel head 43. To eliminate backlash between the nut and screw, and to frictionally prevent unintentional retrograde motion of the ratchet wheel when the pawl is released, a nut 184 also threaded to the screw is keyed to the nut 182 for axial motion relative thereto, and a spring washer 185 is disposed between the When the limit of downward wheel feed has been reached, and the wheel W is to be replaced, upward return motion of the wheel head 43 may be effected by manually turning the ratchet wheel and nut assembly by means of a wrench applied to socket 186 of the ratchet wheel.

FIG. 5 illustrates the mechanism for effecting the motions 38, FIG. 2, for vertical adjustment of the grinding wheel W and for elevating it to permit indexing the cutter, mounting and removal of the cutter, and dressing of the wheel. A cylinder member 191 is secured to the column 36 and slidable in the cylinder bore there is a piston 192 having at its upper end a flanged nut 193 adapted to seat on a ring 194 supported by cylinder head 195. The nut is threaded to a screw 196 journaled for rotation in a radial and axial thrust bearing 197 secured to the bracket 39. On screw 196 is a bevel gear 198 meshing with a pinion 199 rotatable in the bracket. By manual rotation of the pinion, by means of a suitable wrench, the bracket may be raised or lowered to bring the periphery of the wheel into tangency with reference plane 55, FIGS. 1 and -2. A cover 201 which telescopes over the column 36, is movable as a unit with the bracket. An annular piston 202 in the cylinder is slidable on the piston 192 and is adapted for abutment by shoulder 203 of the latter. Slidable in the piston 192 is a tappet 204 urged downwardly relative to the piston by a spring 205, the bottom of the tappet being adapted to ride on a cam or ring on a shaft 206 which is rotatable and also axially shiftable in the column 36. The tappet is shown as seating on a ring 207 concentric with shaft 206, but by manually-effected axial shifting of the shaft, to the left, a cam 208 secured on the shaft may be brought beneath the tappet. Also secured to the shaft is a ratchet wheel 209.

By application of hydraulic pressure through

lines

210 and 211 to

cylinder chambers

212 and 213, piston 202 is held in its down limit position shown, and piston 192 is elevated until its shoulder 203 abuts piston 202. This elevates the bracket 39 to indexing position, wherein the wheel W is clear of the cutter being sharpened. By release of pressure from line 210, pressure in chamber 213 will further raise the piston 192 and cause it to lift the piston 202 into abutment with cylinder head 195. This elevates the bracket 39 to the position wherein a a cutter may be loaded or unloaded and wherein the wheel W is dressed. From either elevated position the piston 192 is lowered by placing line 211 on exhaust and applying pressure through line 214 to chamber 215. Lowering is rapid throughout most of the stroke because spring 205 has lowered the tappet 204 relative to the piston, so that land 216 of the tappet allows fluid exhaust through port 217 in the piston and passage 218 to line 211, but is slowed when the tappet abuts and is arrested by ring 207 (or cam 208). This shifts the piston relative to the land, to close off port 217 and cause the exhaust from chamber 213 to be through a flow restrictor 219. A check valve 221 is closed throughout lowering of the piston but is open while the piston is being elevated.

Ring 2117 is utilized to limit the down motion of the grinding wheel in the case of cutters to be sharpened toa constant depth. In other instances, where different blades around the cutter are to be ground to different depth, a cam 298 especially designed for such cutter is utilized. By means of ratchet wheel 209 and an actuator for it operating in time with the index means for the cutter spindle, the rotation of the cam 208 is correlated with indexing rotation of the cutter. The ratchet wheel actuator may be generally similar to that shown in FIG. 3, and be hydraulically connected to the actuating piston of the cutter spindle index mechanism, described hereinafter.

The dressing mechanism for the grinding wheel appears only partially in FIGS. 1 and 2, and is shown in detail in FIGS. 6 to 8. It comprises a diamond-impregnated dresser wheel 231 having a cylindrical surface 232 for dressing the conical face 32 of wheel W as shown in full lines in FIG. 6 and a concavely radiused surface 233 for dressing a convex edge radius on the wheel as shown in broken lines in the same view. The dresser wheel is journaled for rotation in a dresser arm 234, and is driven by a motor 235 mounted on bracket 39, the drive being through a flexible cable 236 encased in a flexible sheath 237, a bevel pinion 238 journaled in arm 234, and bevel gear 239 rotatable as a unit with the wheel. Arm 234 is secured to a piston rod 241 journaled on ballsleeve bearings 242 for both angular and axial motion in a cylinder housing 243. A piston 244 afiixed to the rod is movable axially by means of hydraulic pressure alternately applied to

chambers

245 and 246. This motion is limited by abutment of end flange 247 of the piston rod with stop 248 and cylinder head 249.

An internal gear segment 251 secured to the piston rod 241 meshes with a pinion 252 rotatable on a stub shaft 253 affixed to the cylinder housing 243. Also meshing with the pinion is a rack 254 on the rod of a piston 255. The latter is reciprocated by alternate application of hydraulic pressure to

chambers

250 and 257 to respectively swing the arm 234 up and down about axis 256 of piston rod 241, the limit positions being determined by abutment of the piston 255 with cylinder heads 25S and 259.

The dressing is accomplished by the two wheels W and 231 being motor driven, at different peripheral speeds. To begin dressing the wheel stroking mechanism is operated to move the wheel W in direction 31, FIG. 1, into the same vertical plane as the dressing wheel 231 and the wheel W is raised as a unit with bracket 39 to dressing position by hydraulic pressure applied through

lines

210 and 211, FIG. 5. By application of pressure to chamber 257, FIG. 7, the dresser wheel 231 is lowered. Ratchet wheel 179, FIG. 3, is advanced one pitch by application of pressure to chamber 174, to feed the Wheel downwardly in direction 45, FIGS. 2 and 4; and the dresser wheel 231, in its lower, broken line position in FIGS. 6 and 7, is shifted to the left in FIGS. 6 and 8 by pressure applied to chamber 246, to thereby dress the edge radius of the wheel W. This motion is such that the dresser wheel axis 261 as viewed in FIG. 6 shifts from the right side of the vertical plane through axis 42 to position 261 to the left of said plane. The dresser wheel is then returned, to the right, by pressure applied to chamber 245, and then is raised, by pressure applied to chamber 259, to dress the conical surface 32 of wheel W. Pressure is released from chamber 174, FIG. 3, causing reset motion of pawl 176, and the bracket 39 is lowered by piston 192 to bring the wheel W to the reference plane 55, FIG. 1. When the wheel is in position W, FIGS. 2 and 6 for sharpening a left hand cutter, the dressing action is the same, except that application of pressure to

chambers

245 and 246, FIG. 8, is reversed, so that the edge radius of the grinding wheel is dressed by motion of the dresser wheel to the right. That is, as viewed in FIG. 6, the dresser wheel axis shifts from position 261 to position 261.

At the conclusion of dressing the bracket 39 and wheel W are lowered to grinding position, wherein the wheel periphery touches plane 55, by piston 192, FIG. 5.

Having now described our improved machine, and its operation, we claim as our invention:

1. A machine adapted to support a substantially frusto-conical grinding wheel in either of two positions, with the wheel axis in one position intersecting the line of the wheel axis in the other position, and with the conical surface of the wheel in said two positions intersecting in parallel lines the common plane of the lines of the wheel axis in said two positions, the machine supporting a dresser wheel with its axis in a plane parallel to and between said lines, said dresser wheel having a cylindrical surface for dressing the conical face of the grinding wheel and a surface of decreasing radius and concave profile for dressing an edge radius on the grinding wheel, means for guiding the dresser wheel for motion (a) of its axis substantially in said common plane and perpendicular to the dresser wheel axis to dress the edge of the grinding wheel, in either position of the latter, with said surface of concave profile and to bring said cylindrical surface substantially to either one of said parallel lines of intersection, and for motion (b) approximately in the direction of the axis of the dresser wheel to dress the conical surface of the grinding wheel with said cylindrical surface.

2. A machine according to claim 1 in which there are means to limit the stroke of motion (a) in both directions, the dresser wheel at one limit being positioned to dress the edge radius of the grinding wheel in one position of the latter and the conical face of the grinding Wheel in the other position thereof, and the dresser wheel at the opposite limit being positioned to dress the edge radius of the grinding wheel in said other position and the conical face of the grinding wheel in said one position.

3. A machine adapted to support a substantially frustoconical grinding wheel in either of two positions, with the wheel axis in one position intersecting the line of the wheel axis in the other position, and with the conical surface of the wheel in said two positions intersecting in parallel lines the common plane of the lines of the wheel axis in said two positions, the machine supporting a dresser wheel with its axis in a plane parallel to and between said lines, means for guiding the dresser wheel for motion (a) of its axis substantially in said common plane and perpendicular to the dresser wheel axis to bring the periphery of the wheel to either one of said lines, and for motion (b) approximately in the direction of the axis of the dresser wheel to dress the conical surface of the grinding wheel.

4. A machine according to claim 3 in which there are means to limit the stroke of motion (a) in both directions, the periphery of the dresser wheel at one limit being positioned to dress the grinding wheel in one position of the latter and at the other limit being positioned to dress the grinding wheel in the other position thereof.

5. A dresser for a grinding wheel comprising a housing having two cylinders with their axes at right angles, a first piston reciprocabie and angular movable in one cylinder, said piston having an arm thereon carrying a dresser tool, a second piston reciprocable in the second cylinder, and gearing connecting said pistons to cause the first piston to be oscillated angularly by and upon reciprocation of the second piston.

6. A dresser according to claim 5 in which said gearing comprises a rack carried by the second piston, a pinion meshing with the rack and supported for rotation in the housing, and a gear meshing with the pinion and carried by the first piston.

7. A machine having a grinding wheel with a conical face, a dresser wheel whose axis is approximately parallel to a cone element of said conical face, said dresser wheel having a cylindrical surface for dressing said conical face and a surface of decreasing radius and concave profile for dressing an edge radius on the grinding wheel, means for guiding the dresser wheel for motion (a) in a radial direction toward and away from said cone element to dress said edge radius with said surface of concave profile and return, and for motion (b) approximately in the direction of the axis of the dresser wheel to dress said conical face with said cylindrical surface.

8. A machine according to claim 7 in which said motion (b) is in an arc tangent to the axis of the dresser wheel about a pivot axis remote from the dresser wheel and perpendicular to said cone element and to the rotation axis of the dresser wheel.

9. A machine according to claim 8 in which the means for guiding the dresser wheel comprise a housing, an arm movable angularly on the housing about said pivot axis for efiecting said motion (b), and said arm being movable relative to said housing along said pivot axis for efiecting said motion (a).

10. A machine according to claim 9 in which there is a fluid actuated piston which carries said arm and is reciprocable in a cylinder in the housing for effecting said motion (a), the axis of said cylinder constituting the pivot axis of the arm, and there is a second fluid actuated piston reciprocable in said housing and connected to the first piston for oscillating it about said pivot axis for effecting said motion (b).

11. A machine according to claim 10 in which the connection between the pistons comprises a rack carried by the second piston, a pinion meshing with the rack and supported for rotation 'by the housing, and a gear meshing with the pinion and carried by the first piston.

References Cited in the file of this patent UNITED STATES PATENTS 1,467,985 Schuvr Sept. 11, 1923 2,067,531 Indge Jan. 12, 1937 2,086,750 .Tanner July 13, 1937 2,171,902 1 Wood Sept. 5, 1939 2,323,401 Johnson July 6, 1943 2,565,013 Bargren Aug. 21, 1951 2,697,426 Price et al. Dec. 21, 1954 2,792,672 Carlsen et al. May 21, 1957 2,826,008 Dunn Mar. 11, 1958 2,963,017 Norel et al. Dec. 6, 1960 2,972,343 Dunn Feb. 21, 1961