US2834159A - Centerless grinding machine - Google Patents

Description

y 3, 1958 o. E. HILL 2,834,159

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet 3 INVENTOR OIVA 1 H/L L.

BY Mw-W A TTOENEY y 3 958 o. E. HILL 2,834,159

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet 4 INVENTOR 'OIVA E. HILL ATTOENEY y 3, 1958 o. E. H'ILL 2,834,159

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet 5 INVENTOR 0/ VA E. HILL ATTQENEYV May 13, 1958 o. E. HILL CEIIITERLESS GRINDING MACHINE l4 Sheets-Sheet 6 Filed April 16, 1956 INVENTOR VA E. HILL BY Mum.

. ATTOENEY o. E. HILL 2,834,159

CENTERLESS GRINDING MACHINE May 13, 1958 Filed April 16, 1956 14. Sheets-Sheet 9 INVENTOR UIVA E. HILL.

y 3 958 o. E. HILL 2,834,159

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet 10 INVENTOR 0 NA E. H/LL y 3, 1958 o. E. HILL 2,834,159

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet ll Pay. 8 393 403 360370 377 3703 INVENTOR O/VA E. HILL Mbbexin ATTORNEY May 13, 1958 I o. E. HILL 2,334,159

CENTERLESS GRINDING MACHINE Filed April 1a, 1956 14 Sheets-sheet 12 INVENTOR OIVA E. H/LL A TTOE/VEY 3, 1958 o. E. HILL 2,834,159v

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet 13 Z0 INVENTOR O/VA E. HILL,

ATTORNEY May13, 1958 o. E. HILL 2,834,159

CENTERLESS GRINDING MACHINE Filed April 16, 1956 14 Sheets-Sheet 14 L/ F- L? 6w/ vgja l AuTo.

MAFUA LCI K CC! I UTO.

PLUNGE Cur INVENTOR O/VA E. HILL ATTORNEY United States Patent CENTERLESS GRINDING MACHINE Oiva E. Hill, West Boylston, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application April 16, 1956, Serial No. 578,412

27 Claims. (Cl. 51-103) The invention relates to grinding machines, and more particularly to centerless grinding machines.

One object of the invention is to provide a small and throughly practical centerless grinding machine. Another object is to provide a centerless grinding machine which may be set up for either straight-through or plunge-cut grinding. Another object is to provide a simplified truing apparatus for truing both the grinding wheel and the regulating wheel. Another object is to provide a work size control mechanism automatically to control work size on either plunge-cut or straight-through grinding. Another object of the invention is to provide a work size control mechanism which is operative after a predetermined number of work pieces have been ground either over size or under size to automatically impart a compensating adjustment to the wheel feeding mechanism.

Another object is to provide an automatic wheel truing mechanism for truing the grinding wheel after a predetermined number of work pieces have been ground.

Another object is to provide a compensating mechanism automatically to advance the grinding wheel before atruing operation is initiated. A further object of the invention is to provide a compensating mechanism automatically to impart a forward compensation to the wheel feeding mechanism when the ground work pieces are over size. Another object is to provide a compensating mechanism automatically to impart a rearward compensation adjustment to the wheel feeding mechanism when work pieces are ground under size. Another object is to provide an independent forward and rearward compensating mechanism for the wheel feeding mechanism which is automatically controlled by the work size mechanism. Other objects will be in part obvious, or in part pointed out hereinafter.

One embodiment of the invention has been illustrated in the drawings;

Fig. l is a front elevation of the centerless grinding machine, having parts broken away and shown in section;

Fig. 2 is a rear elevation of the centerless grinding machine, showing the grinding and regulating wheel driving mechanism;

Fig. 3 is a vertical sectional view, on an enlarged scale, taken approximately on the line 3-3 of Fig. 2, through the grinding wheel spindle and bearings;

Fig. 4 is a vertical sectional view, on an enlarged scale, taken approximately on the line 4-4 of Fig. 2, through the regulating wheel spindle and bearings;

Fig. 5 is a fragmentary vertical sectional view, on

an enlarged scale, through the feed screw and nut showing a portion of the feed compensating mechanism;

Fig. 6 is a fragmentary sectional view, taken approxinism;

mately on the line 6-6 of Fig. 5, through the feed 2,834,159 Patented May 13,1958

an enlarged scale, taken approximately on the line 8-8 of Fig. 7, through the feed compensating mechanism;

Fig. 9 is a vertical sectional view, on an enlarged scale, taken approximately on the line 9-9 of Fig. 1, of the truing tool wear compensating adjusting mecha Fig. 10 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 10-10 of Fig. 1, through the wheel feeding mechanism;

Fig. 11 is a fragmentary vertical sectional view, taken approximately on the line 11-11 of Fig. 5 through the feed compensating mechanism;

Fig. 12 is a vertical sectional View, on an enlarged scale, taken approximately on the line 12-12 of Fig. 11, through the one-way ball clutch; I

Fig. 13 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 13-13 of Fig. 1, through the clamp on the feed screw mechanism;

Fig. 14 is a vertical sectional view, on an enlarged scale, taken approximately on the line 14-14 of Fig. 1, through the regulating wheel slide showing the slide arrangement and the pivotal support for the regulating wheel;

Fig. 15 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 15-15 of Fig. 2, through a portion of the driving mechanism, showing the drive for the coolant and lubricant pumps;

Fig. .16 is a plan view, on an enlarged scale, of the work rest, work guides, and truing tool for use in a straight through grinding operation;

Fig. 17 is a vertical sectional view, on an enlarged scale, taken approximately on the line 17-17 of Fig. 16, showing the work rest and work guides in elevation;

Fig. 18 is a vertical sectional view, taken approximately on the line 18-18 of Fig. 17;

Fig. 19 is a vertical sectional view, taken approximately on the line 19-19 of Fig. 17; I

Fig. 20 is a fragmentary plan view of the truing tool arranged for truing a slight taper on the entering portion of the grinding wheel; I

Fig. 21 is a plan view, on an enlarged scale, of the work rest and the wheel truing apparatus for use in a plunge-cut grinding operation;

Fig. 22 is a vertical sectional view, taken approximately on the line 22-22 of Fig. .21, showing the work rest and truing apparatus in elevation;

Fig. 23 is a vertical sectional view, taken approximately on the line 23-23 of Fig. 22 through the work rest and the wheel truing apparatus;

Fig. '24 is fragmentary rear'elevation of the grinding machine, showing a modified driving mechanism for the grinding wheel, regulating wheel and pumps;

Fig. 25 is an end elevation of the machine showing the modified driving mechanism having parts broken away and shown in section to illustrate the internal. construction;

Fig. 26 is a horizontal sectional view, on an enlarged scale, taken approximately on the line 26-26 of Fig. 25;

Fig. 27. is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 27-27 of Fig. 25;

Fig. 28 is a vertical sectional view of a modified form of the truing apparatus, irr which the truing tool for the regulating wheel is independently adjusted;

Fig. 29 is a vertical sectional view, through the work rest, showing a modified form of wheel truing apparatus for truing the peripheral phases of the winding and regulating wheels and an angular face of the grinding wheel;

Fig. 30 is a fragmentary plan view of the truing apparatus as shown in Fig. 29; Fig. 31 is a fragmentary plan view of a modification of the truing appartus as shown in Fig. 30 in which a cam-actuated mechanism is provided to oscillate the side truing tool;

Fig. 32 is a fragmentary diagrammatic plan view showing the arrangement of the truing tools with relation to the grinding and regulating wheels and of the work rest as shown in Fig. 28;

Fig. 33 is a similar diagrammatic view showing a modification of the truing arrangement shown in Fig. 21, illustrating the relationship of parts for truing the grinding and regulating wheels for grinding the tapered work;

Fig. 34 is a similar diagrammatic plan view showing a modification of the arrangement shown in Fig. 21 in which the regulating wheel is swivelled and trued by use of a forming bar while the truing tool slide is swivellcd to travel parallel to the axis of the grinding wheel to true the same;

Fig. 35 is a similar diagrammatic plan view showing a modification of the arrangement in Fig. 21 with the regulating wheel swivelled and trued by use of a forming bar while the truing slide is swivelled to travel in a direction parallel to the axis of the grinding wheel;

Fig. 36 is a similar diagrammatic plan view showing a modification of the arrangement in Fig. 21 in which the regulating wheel is ttued by use of a forming bar and the grinding wheel is trued by a longitudinal movement of the truing tool slide;

Fig. 37 is a hydraulic diagram of the actuating mechanisms and the controls therefor; and

Fig. 38 is an electric wiring diagram.

A centerless grinding machine has been illustrated in the drawings comprising a base It) which supports a transversely movable grinding wheel slide 11. The base it is provided with a pair of spaced upwardly extending ribs 12 and 13, which are provided with V- ways 14 and 15, each of which supports a row of balls 16 and 17. The under side of the wheel slide 11 is provided with a V-way 18 and a flatway 19 to form an anti-friction slideway for the wheel slide 11.

The wheel slide 11 supports a rotatable wheel spindle in a pair of spaced bearings 26 and 27. The righthand end of the wheel spindle 25 is supported by an antifn'ction bearing 28. A wheel guard 29 surrounds a grinding wheel 34 supported on the wheel spindle 25. A removable cover plate 30 is detachably fastened to the lefthand side face of the wheel guard 29. The cover plate 30 is provided with a cylindrical aperture 31, which mates with the outside diameter of the bearing 26. The grinding wheel spindle 25 is provided with a slidably keyed wheel mount 32. A clamping flange 33 is screw threaded onto the Wheel mount to facilitate clamping the grinding wheel 34 on to the mount 32 in fixed relation to the spindle 25. In order to mount a grinding wheel 34 on the spindle 25, the cover plate 30 is removed in an axial direction, without disturbing the bearing 26, after which the grinding wheel 34 may be mounted on the mount 32, and the flange 33 clamped to lock the wheel on the spindle.

A driving mechanism is provided for the wheel spindle 25 comprising an electric motor 35 which is mounted on a transversely adjustable motor base 36, supported on the upper surface of the wheel slide 11. The motor 35 is provided with a multiple V-groove pulley 37, which is connected by multiple V-belts 38 with a pulley 39 which is mounted on the right-hand end of the wheel spindle 25 (Fig. 3).

An adjusting screw 40 is rotatably supported by a bracket 41 fastened to the right-hand. or rear end of the wheel slide 11 (Fig. 2). The screw 40 is screw threaded into a threaded aperture 42 formed in the motor base 36. By manipulating the screw 40, the portion of the motor base 36 and the motor 35 may be adjusted to properly tension the driving belts 38.

A feeding mechanism is provided for feeding the wheel slide 11 transversely. This mechanism. comprises a rotatable feed screw 45 (Fig. 1), which is supported at its threaded onto the left-hand end of the nut 53.

4 left-hand end by an anti-friction bearing 46, which is, in turn, supported by a slidably mounted sleeve 47. The sleeve 47 is slidably keyed within a cylindrical aperture 48 formed in the base 10.

A reduced cylindrical portion 49 of the feed screw 45 is slidably keyed within a rotatable sleeve 50, which is journalled in an anti-friction bearing 51, supported by the base 10.

The wheel slide 11 is provided with a depending bracket 52 which rotatably supports a feed nut 53 (Fig. 5), in a pair of spaced anti-friction bearings 54 and 55. The feed nut 53 is provided with an integral flange 56 at its right-hand end. The flange 56 bears against the righthand surface of the bearing 55. A collar 57 is screw y manipulating the nut 57, the thrust between the feed nut 53 and the bearings 54 and 55 may be readily adjusted.

A backlash eliminating mechanism is provided to take up backlash between the feed screw 45 and the feed nut. 53. This mechanism comprises a collar 58, which is screw threaded onto the feed screw 45 (Fig. 5) and adjustable collar 59, which is screw threaded onto the collar 58. A plurality of compression springs 5942 are provided between the collar 59 and the right-hand end face of the flange 56. By manipulation of the collar 59, the compression of the springs 59a may be varied as desired to eliminate backlash between the feed screw 45 and the feed nut 53.

A manually operable feeding mechanism is provided for rotating the feed screw 45. A shaft 60 is slidably keyed within the right-hand end of the sleeve 50 (Fig. l). The right-hand end of the shaft 60 is supported by an antifriction bearing 61 fixedly supported relative to the base It). A bevel gear 62. is mounted on the right-hand end of the shaft 60 (Fig. l) and meshes with a bevel gear 63 (Fig. 10) mounted on the right-hand end of a rotatable shaft 64. The shaft 64 is journalled in an anti-friction bearing 65. A rotatable shaft 66 is slidably keyed onto the left-hand end of the shaft 64 (Fig. 10).

A manually operable feed wheel 67, having a micrometer adjusting mechanism 68, is rotatably supported by a shaft 69 on the front of the machine base. The feed wheel 67 is provided with a pinion 70 (Fig. 10) which meshes with a gear 71 rotatably supported on the shaft 69. A gear 72 is fixedly mounted to rotate with the gear 71 on the shaft 69. The gear 72 meshes with a gear 73 which is fixedly mounted on the left-hand end of the shaft 66. It will be readily apparent from the foregoing disclosure that a rotary motion of the feed wheel 67 will be imparted through the gear mechanism above described to impart a rotary motion to the feed screw 45 so as to cause a transverse movement of the wheel slide 11 and the grinding wheel 34.

A hydraulically operated mechanism is provided for feeding the grinding wheel 34'toward and from the work piece and regulating wheel during a plunge-cut grinding operation. This mechanism comprises a cylinder 74 (Figs. 10 and 24) which contains a slidably mounted piston 75. The upper surface of the piston 75 is provided with rack teeth 76 which mesh with a gear 77. The gear 77 is rotatably supported by a pair of space bearings 78 and 79. A shaft 80 passes through a central hole in the gear 77, and is connected at its right-hand end (Fig. 10) by a manually operable clutch 81. The clutch 81 serves to engage or disengage a gear 82 to transmit rotary motion from the gear 77 to the gear 82. The gear 82 meshes with a gear 83 mounted on the shaft 66. It will be readily apparent from the foregoing disclosure that when fluid under pressure is passed through a pipe 85 into the left hand end of the cylinder 74, the piston 75 will be moved toward the right to impart a rotary motion through the gear mechanism above described, to rotate the feed screw 45 so as to cause a transverse feeding movement to be imparted to the wheel slide 11 and the grinding wheel 34.

Dur'in movement of the piston 75 toward the right (Fig. 24) fluid is exhausted from the right-hand end of the cylinder 74 through a pipe 86.

A clamping mechanism is provided for holding the sleeve 50 against rotary motion when the machine is set up for a straight through grinding operation. This clamping mechanism comprises a collar 87, which surrounds the left-hand end of the sleeve 50.

The collar 87 is provided with a slot 88. A clamping screw 89 is provided to clamp the collar 87 to hold the sleeve 50 against rotation. This is particularly useful when the machine is set up for a straight through grinding operation where it is not desirable to have the feed screw 45 free to rotate. By providing this clamp, the feed screw 45 may be positively locked so that a compensating adjustment may be made by a rotary motion of the feed nut 53 as will be hereinafter described.

When the machine is set up for a plunge-cut grinding operation, the feed screw 45 may be manually rotated by rotation of the feed wheel 67 in a counter-clockwise direction. During the setting-up operation, the manually operable knob 84 (Fig. may be shifted toward the right to disengage the clutch 81. The feed wheel 67 is rotated in a counter-clockwise direction until a stop abutment 20, adjustably supported bythe feed wheel 67, moves into engagement with a stop surface 21 on a pivotally mounted feed pawl 22. The feed pawl 22 is pivotally supported by stud 23 on the front of the machine base, and is normally held in an operative position by means of a tension spring 24. By manipulation of the micrometer feed adjusting mechanism 68, the stop abutment may be adjusted relative to the feed wheel 67, so as to stop the in-feeding movement of the grinding wheel 34 when a work piece has been ground to a predetermined size.

After the stop abutment 20 has been adjusted, the knob 84 may be shifted toward the left to engage the clutch 81, so that an in-feeding movement of the feed screw may be obtained by fluid pressure actuation of the piston 75.

When the machine is set up for a straight through grinding operation, the feed mechanism is adjusted so that when the stop abutment 20 on the feed wheel 67 is in engagement with the stop surface 21, the grinding wheel 34 will be positioned to grind work-pieces to a predetermined size. When the parts are in'this position, the clamping screw 89 is actuated to clamp the clamping ring 87 to lock the sleeve against rotary motion. Any feeding movement of the grinding wheel to compensate for wheel wear may thereafter be made by means of a co-mpensating mechanism which imparts a rotary adjustment to the feed nut 53, as will be hereafter described.

A pair of compensating mechanisms are provided; one for imparting a compensating adjustment to the feed nut 53 during a forward compensating adjustment of the grinding wheel, and the other to impart a rearward compensating adjustment thereto. As shown in Figs. 5 and 11, a worm gear 90 surrounds the feed nut 53, and is connected thereto by means of a roller one-way clutch 91.

A Worm 92 mounted on a vertically arranged rotatable shaft 93, meshes with the worm gear 90. The shaft 93 is supported by a plurality of spaced anti-friction bearings 94, 95, and 96. The upper end of the shaft 93 is provided with a worm gear 97 which meshes with a worm 98 mounted on a horizontally arranged shaft 99. The shaft 99 is supported by a plurality of spaced bearings 100, 101, 102, and 103 (Fig. 11).

A pawl and ratchet mechanism is provided for imparting a rotary motion to the shaft 99. This mechanism comprises a ratchet wheel 105 mounted adjacent to the left-hand end of the shaft 99 (Fig. 11). A pivotally mounted pawl 106 is arranged to engage the teeth of the ratchet wheel 105, and is pivotally supported by a piston 107 slidably mounted within a cylinder 108.

A compression spring 109 serves normally to hold the,

piston 107 in a downward position (Fig. 8 An adjust able stop screw 110 is providedto limit the upward movement of the piston 107, thereby determining the extent of compensating adjustment which is imparted to the feed nut 53. When fluid under pressure is passed through a pipe 111 into a cylinder chamber 112, the piston 107 will move upwardly until the upper surface thereof engages the stop screw 110. During the upwardmovement of the piston 107, the pawl 106 imparts a rotary motion to the ratchet wheel 105, which serves through the mechanism previously described to impart a rotary motion to the worm gear 90 in a counter-clockwise direction. This rotary motion of the worm gear 90 serves through the roller one-way clutch to impart a counter-clockwise rotary adjustment to the feed nut 53. A manually op erable knob 113 is mounted on the left-hand end of the shaft 99 (Fig. 11).

An independent hydraulically operated mechanism is shaft also supports a gear 121, which meshes with a small gear 122. The small gear 122 is connected through a roller-type one-way clutch 123 with the shaft 99. A

stop screw. 124 is provided to determine the stroke of the piston 116 and the rack bar 118.

When fluid under pressure is passed through a pipe 125, the piston 116 will be moved toward the right so .as to impart a rotary motion to the shaft 99 is a counterclock wise direction (Fig. 12), so as to impart a compensating adjustment to the feed nut 53 in a counter-clockwise direction.

A similar feed compensating mechanism is provided for imparting a rearward compensating adjustment to the. wheel slide 11 and the grinding wheel 34. This mecha-.

nism comprises a worm gear which surrounds the feed nut 53 and is connected thereto by a roller-type one-way clutch 131. The worm gear 130 meshes with a worm 132 mounted on a vertically arranged shaft 133, which 'is' rotatably supported in spaced bearings 134, 135, and 136 (Figs. 5 and 6). The upper end of the shaft 133 is provided with a worm gear 137 which meshes with a worm 138 mounted on a rotatable shaft 139 (Figs. 5 and 7). The shaft 139is supported in spaced bearings (not shown) and is arranged substantially parallel to the shaft 99. The shaft 139 is provided with a ratchet wheel 141 (Figs. 7 and 8). The ratchet wheel 141' is'arranged to be engaged by a pivotally mounted pawl 142 carried by a piston 143. The piston 143 is slidably mounted within a cylinder 144. A compression spring 145 serves nor-' mally to hold the piston 143 in a downward position. An adjustable stop screw 146 is provided to limit the upward movement of the piston 143, thereby determining the extent of compensating adjustment imparted to the feed nut 53.

When fluid under pressure is passed through a pipe 147 into a cylinder chamber 148, formed at the lower end of the cylinder 144, an upward movement of the piston .143 is obtained. During the upward movement of the piston 143, the pawl 142 imparts a rotary motion to the ratchet wheel 141 in a counter-clockwise direction, which is trans mitted through the mechanism above described to impart a rotary motion to the worm gear 130 in a clockwise.

ment of the worm gear 90, and a rearward compensating. o a y ,a

adjustment .is made by imparting a clockwise justment to the worm gear 130.

A fluid pressure system is provided to supply under pressure for the various actuating mechanism of the machine. This system may comprise a motor-driven fluid pump 150 which draws fluid through a pipe 151 from a reservoir 152, and passes fluid under pressure through a pipe 153. A relief valve 154 is provided in the pressure pipe 153 to facilitate passing excess fluid under pressure directly to the reservoir 152, so as to maintain a substantially uniform pressure within the system (Fig. 37).

A hydraulically operated mechanism is provided to facilitate moving the wheel slide 11 into a grinding position or into a truing position. This mechanism comprises a cylinder 155 which is arranged in axial alignment with the sleeve 47 and the feed screw 45. The cylinder 155 contains a slidably mounted piston 156, which is connected to the left-hand end of a piston rod 157. The right-hand end of the piston rod 157 is connected to the slidably mounted sleeve 47.

When fluid under pressure is passed through a pipe 158 (Fig. 37) into a cylinder chamber at the left-hand end of the cylinder 155, the piston 156, together with the feed screw 45, the wheel slide 11, and the grinding wheel 34, move toward the right (Fig. 1) into a grinding position. In this position of the parts, the piston 156 is in engagement with the right-hand end of the cylinder 155. During this movement of the piston 156, fluid may exhaust from the cylinder chamber at the right-hand end of the cylinder 155 through a pipe 159.

A control valve 168 is provided for controlling the admission to, and exhaust of fluid from the cylinder 155. The valve 168 is a piston-type valve, comprising a slidably mounted valve member 169, having a plurality of spaced valve pistons formed integrally therewith to form a plurality of valve chambers 170, 171, and 172. The valve 169 is normally held in a left-hand end position by a compression spring. A solenoid S4 is provided which, when energized, serves to shift the valve 169 into a right-hand end position. In the position of the parts (Fig. 37) fluid under pressure from the pressure pipe 153 enters the valve chamber 171 and passes through the pipe 158 into the cylinder 155 to move the piston 156 toward the right into a grinding position. During this movement, fluid exhausting from the cylinder 155 through the pipe 159 enters the valve chamber 172, passes through a central passage 205 in the valve 169, into the valve chamber 170, and exhausts through a pipe 206 and throttle valve 207. By manipulation of the throttle valve 207, the rate of movement of the piston 156 may be readily controlled as desired.

When the solenoid S4 is energized, fluid under pressure entering the valve chamber 171 passes through the pipe 159 into the right-hand end of'the cylinder 155, to move the piston 156, together'withthe feed screw 45, the wheel slide 11, and the grinding wheel 34 toward the left (Figs. 1 and 37') intoa rearward or trui-n'g position.

The rearward movement of the wheel slide continues until the left-hand end' of the piston rod 157 engages an adjustable stop 160 which determines the position of the grinding wheel or a truing operation.

The stop 160 is formed integral with a screw 161 which is screw threaded in a central aperture at the end cap 162. In order to facilitate a precise adjustment of the stop 160, a worm gear 163 is slidably keyed onto the stop 160. The work gear 163 meshes with a worm 164, which is mounted} on a rotatable shaft 165. A manually operable graduated knob 166 is provided for rotating the shaft 165 and the worm 164'. An index pointer 167, fastened to the end cap 162', serves to facilitate positioning the graduated knob 166. It will be readily apparent from the foregoing disclosure that a rotary motion of the knob 166 will be imparted through the worm 164 and the worm gear 163, to rotate the screw 161 and thereby adjust the position of the stop 160. This adjustment serves to facilitate a precise adjustment of the grinding wheel for grinding wheel truing operation to be hereafter described.

The base 10 also supports a regulating wheel 191 for controlling the rate of rotation of a work piece during a grinding operation. A regulating wheel base (Figs. 12 and 14) is mounted on the base 10 and serves as a support for a transversely movable regulating wheel slide 176. The regulating wheel base 175 is provided with a dovetailed slideway 177 which mates with a correspondingly shaped slidway formed on the under side of the slide 176. An adjustable gib 174 (Fig. 14) is provided between the parts of the slideway 177. The gib 174 may be adjusted by a manually operable screw 173 to take up lost motion in the slideway, and also to facilitate clamping the regulating wheel slide 176 onto the regulating wheel base 175 when desired. A pair of cylindrical end caps 179 and are fixedly mounted on an upwardly extending part of the slide 176 (Figs. 1 and 14). The end caps 179 and 180 are provided with cylindrical surfaces 181 and 182 respectively which serve to pivotally support a frame 183 which carries the regulating wheel 191 as will be hereinafter described.

A clamping screw 127 passes through a clearance hole in the flanged end cap 180 (Fig. l) and is screw threaded into the hollow frame 178. The clamping screw 127 serves to clamp the frame 183 carrying the regulating wheel 191 to the regulating wheel slide 176. For a straight-through grinding operation, it is desirable to skew or swivel the regulating wheel axis in a vertical plane parallel to the axis of the grinding wheel axis in order to impart a feeding component to the workpieces being ground. This is accomplished by loosening the clamping screw 127 and then actuating the adjusting screw 184 so as to swivel the frame 183 to the desired extent relative to the regulating wheel slide 176 after which the clamping screw 127 is tightened to clamp the frame 183 in adjusted position.

The frame 183 is provided with an adjusting screw 184 (Fig. 14) the end of which bears against a surface 262 formed on the regulating wheel slide 176 to facilitate tilting the frame 183 relative to the slide 176. The frame 183 serves as a support for a plurality of spaced bearings 186, 187 and 188 which rotatably support a regulating wheel spindle (Fig. 4). The frame 183 is provided with an integral wheel guard 189 which partially surrounds the regulating wheel 191. The regulating wheel 191 is clamped onto the spindle 185 by a pair of clamping flanges 195 and 196 which are screw threaded onto the spindle.

The variable speed transmission unit 221 is provided to facilitate rotating the spindle 185 and the regulating wheel 191 either at a relatively slow speed to control the rate of rotation of workpieces during a grinding operation, or at a relatively fast speed suitable for a Wheel truing operation.

In order to facilitate mounting the regulating wheel 191 on the spindle 185, the left hand open end of the wheel guard 189 (Fig. 4) is partially enclosed by a removable cover plate 190. The plate is provided with an internal cylindrical bore 193 which mates with an external cylindrical surface of a sleeve 194. The sleeve 194 serves as a support for the spindle bearing 186. When it is desired to mount a regulating wheel 191 on the spindle 185, the cover plate 190 is detached from the Wheel guard 189 and moved in an axial direction from the sleeve 194 without disturbing the spindle bearing 186. The flange 195 is unscrewed from the spindle 185 after which the regulating wheel 191 is slid in an axial direction in position on the spindle 185, or a worn out wheel may be romoved and replaced with a new wheel 191.

The regulating wheel base 175 is arranged so that it may be swivelled in a horizontal plane about the axis of a pivot stud 203 (Fig. l) which is fixedly mounted on the base 10 to facilitate adjusting the axis of the regulating wheel spindle 185 relative to the axis of the grinding wheel spindle 25.

A downwardly projecting lub 204 is fixedly mounted on the right hand end of the regulating wheel base 175 (Fig. 1). The lug 204 projects downwardly between a pair of spaced adjusting screws 208 and 209 which are supported by the machine base 10. It will be readily apparent that by manipulation of the screws 208 and 209, the regulating wheel base 175 may be adjusted in a horizontal plane to position the axis of the regulating wheel spindle 185 into the desired relationship with the grinding wheel spindle 25, after which it may be clamped in adjusted position. The axis of spindle 185 may be positioned parallel to or at an angle to the axis of the spindle 25, as desired. A feeding mechanism is provided for adjusting the position of the regulating wheel slide 176 relative to the base and the regulating wheel base 175. This mechanism comprises a feed screw 197 rotatably supported by an anti-friction bearing 198 carried by the end cap 180. The feed screw 197 meshes with or engages a threaded aperture 200 formed in a vertically arranged bracket 201 (Fig. l) which is fixedly mounted on the regulating wheel base 175. A feed wheel 199 is mounted on the right hand end of the feed screw 197. By manipulation of the feed wheel 199, the position of the regulating wheel slide 176 and the regulating wheel 191 may be adjusted transversely, to facilitate positioning the regulating wheel 191 into the desired relationship with the grinding wheel 34.

As shown in Fig. 2, the electric motor 35 serves to drive the grinding wheel 34 and also the regulating wheel 191 and the pumps to be hereinafter described. The pulley 37 is connected by multiple V-belt 210 with a pulley 211 mounted on a shaft 212. The shaft 212 is rotatably supported by a pair of spaced bearings 235 and 236 which are supported within a housing 237. The housing 237 is fixedly mounted on the upper end of' a sleeve 213. The sleeve 213 is supported by a vertically arranged column 214 (Figs. 2 and The column 214 is fixedly supported on top of a coolant pump 215 which is fixedly mounted on the base 10.

An adjusting screw 216 supported by the column 214 is provided to facilitate a vertical adjustment of the sleeve 213 so as to tension the driving belt 210. A pair of clamping screws 217 are provided on the sleeve 213 to facilitate clamping the sleeve 213 in adjusted position relative to the column 214. The shaft 212 is provided with a bevel gear 240 which meshes with a bevel gear 241 mounted on the upper end of a vertical rotatable shaft 242. The lower end of the shaft 242 is slidably keyed within a sleeve 243 which is fixedly mounted on the upper end of a drive shaft 244 of the coolant pump 215. The coolant pump 215 serves to supply coolant fluid to the work being ground and to the grinding and regulating wheels during a grinding operation, and also to supply coolant to the truing tools and wheels during a truing operation.

The shaft 212 also supports a pulley 218 which is connected by a V-belt 219 with a pulley 220 on a drive shaft 225 of a variable speed hydraulic transmission unit 221. This unit may be any of the well known commercial units, now on the marget, such as for example that manufactured by Vickers Inc. of Detroit, Michigan. The unit 221 is mounted on a platen 222 which is pivotally supported at its upper end on a rock shaft 223. An adjusting screw 224 is connected between the lower end of the platen 222 and the base 10 to facilitate swinging the unit 221 so as to tension the V-belt 219 as desired. The

driven shaft of unit 221 is provided with a driven pulley nected by V-belts 233 with'the pulley 192' on the regulat ing wheel spindle to drive the regulating wheel 191. The tension of the belt 233 may be adjusted by a horizontal adjustment of the bracket 231 relative to the slide 176. The tension of the belt 227 may be adjusted by a vertical adjustment of the bracket 230 relative to the bracket 231. It will be readily apparent from the foregoing disclosure that the motor 35 (Figs. 1 and 2) serves to drive the grinding wheel 34, the regulating wheel 191 and the coolant pump 215; and pump 150.

Referring now to Figs. 16, 17, 18, 19 and 20, a work guide, workrest and wheel truing apparatus have been illustrated for a straight -through grinding operation. A plate 250 (Fig. 17) is fixedly mounted on the regulating wheel slide base 175. The plate 250 supports a plate 251 which in turn supports a longitudinally extending plate 252. The plate 252 serves as a support for a longitudinally movable slide 253. Anti-friction slideways are provided between the plate 252 and the slide 253. The plate 252 is provided with a pair of spaced parallel longitudinally extending V-ways 254 and 255 (Figs. 18 and 19). The slide 253 is provided with an adjustable gib 248 having a long extending V-way 256 arranged opposite the V-way 254. The slide 253 is provided with a V-way 257 arranged opposite the V-way 255. A pair of spaced rows of balls 258 and 259 are interposed between the V- ways 254-256 and V-ways 255 -257 respectively to form an anti-friction support for the slide 253. The gib 248 is provided with taper (Fig. 16) extending longitudinally to facilitate taking up lost motion between the slideway parts. An adjusting screw 249 is provided to facilitate a longitudinal adjustment of the gib 248 relative to the slide 253.

The plate 252 is arranged so that it may be swivelled in a horizontal plane about the axis of a pivot stud 251a which is carried by the plate 251. A clamping screw 246 (Fig. 17) passes through an elongated arcuate slot 247 and is screw threaded into the plate 252 to facilitate clamping the plate 252 in adjusted position. This swivel adjustment isprovided so that the slide 253 may move in a direction parallel to the axes of the grinding wheel 34 and the regulating wheel 191, or at an angle thereto.

' A work rest base 260 (Figs. 16 and 17) is fixedly mounted on the slide 253. The base 260 is provided with a longitudinally extending groove 261 to support a. work rest blade 262 having an upper work supporting surface 263 which shapes downwardly toward the regulating wheel 191 (Figs. 1 and 2) for supporting work pieces during a grinding operation. The work-rest blade 262 is vertically adjustable by means of a pair of adjusting screws 265 and 266 (Fig. 17) which are screw threaded into the base 260. Lock nuts 267 and 268 are provided on the screws 265 and 266 respectively to facilitate locking the screws in adjusted position. extending portion 260 of the work rest base 260 is provided with a plurality of spaced vertical elongated slots 269, 270, 271 and 272 (Fig. 17). A plurality of clamping screws 273, 274, 275 and 276 pass through the slots 269, 270, 271 and 272 respectively and are screw threaded into the work rest blade 262 to facilitate clamping it in adjusted position. It will be readily apparent from the foregoing disclosure that by loosening the screws 273, 274, 275 and 276 and ,thenadjusting the screws 265 and 266, the position of theblade 262 may be adjusted vertically so as to position the axis of the work piece being ground relative to the axes of the grinding wheel 34 and the regulating wheel 191 after which the blade 262 may be clamped in adjusted position.

The work rest base 260 is arranged to swivel in a horizontal plane about the axis of a pivot stud 260a which is carried by the slide 253. A plurality of clamping screws 277 pass through elongated slots 278 in the work rest base 260 and are, screw threaded into the slide 253 to clamp the work rest base .260 in adjusted position. This swivel adjustment is provided to facilitate adjusting The upwardly 1 11 the position of the work rest 262 relative to the slide 253, and relative to the axes of the grinding wheel 34 and the regulating wheel 191.

A work guiding arrangement is provided to guide successive workpieces along the rest blade 262 to and from a grinding position. The plate 251 is provided with an upwardly extending bracket 280 (Fig. 18) which supports a horizontally adjustable bracket 281. The bracket 281 is clamped onto the bracket-280 by a pair of clamping screws 282 and 283. The clamping screws 232 and 283 pass through elongated slots 284 and 235' formed in the bracket 281 and are screw threaded into the bracket 280. The upper portion of the bracket 281 is provided with a work guiding plate 286. A vertical bracket 287 (Fig. 18) is provided with a work guiding plate 238 which is opposed to the plate 286. The bracket 287 is pivotally supported on the base 260. A horizontal hole 289 passes through the lower end of the bracket 287. A conically shaped stud 290 on the rest base 260 (Fig. 17) engages a correspondingly shaped aperture at the right hand end of hole 289. A conically shaped set screw 291 engages a correspondingly shaped left hand end portion of the hole 289. The stud 290 and set screw 291 serve as pivotal supports for the bracket 287. A compress spring 292 normally tends to move the bracket 287 in a clockwise direction (Fig. 18) to maintain a stop screw 293 in engagement with the upwardly extending portion of the rest base 260 so as to form a yielding support for the work guiding plate 288. By adjusting the stop screw 293 relative to the bracket 287, the spacing of the work guiding plates 286 and 288 may be regulated as desired to accommodate workpieces of different diameters.

A pair of vertically arranged brackets 300 and 301 are pivotally supported by a stud 302 (Figs. 17 and 19) adjacent to the other end of the workrest base 260. A pair of spaced work guide plates 303 and 304 are mounted on the brackets 300 and 301 respectively to serve as work guides to guide ground workpieces as they pass from the grinding throat between the wheels to a discharge chute (not shown). A pair of adjusting screws 305 and 306 are provided on brackets 300 and 301 respectively to facilitate adjustment of the guide plates 303 and 304 to accommodate workpieces of different diameters.

A grinding wheel truing apparatus is provided to facilitate truing the operative face of the grinding wheel 34 when desired. This apparatus comprises a truing tool 307 which mounted on a holder 308 mounted on the bracket 287. The truing tool 307 is preferably positioned to true the operative surface of the grinding wheel 34 when it is in an extreme rearward or inoperative position, that is, with the left hand end of the piston rod 157 in engagement with the adjustable stop 160.

The truing tool holder 308 is preferably adjustably and detachably mounted on the bracket 287. The holder 303 is provided with a vertically arranged dovetailed slideway 309 which mates with a corresponding shaped way on the member 287. A clamping screw 310 is provided to facilitate clamping the holder 308 to the member 237. A vertically arranged adjusting screw 311 is provided to vertically adjust the holder 208 relative to the member 28? to facilitate positioning the truing tool 307 in the desired relationship with the grinding wheel 34.

In setting up the machine and also at infrequent intervals during use, it may be desirable to true the peripheral operative surface of the regulating wheel 191. The guide plate 238 is removed from the bracket 287 by loosening a clamping plate 340. A second truing tool holder 341 is supported by a dovetail slideway 342 on the bracket 287. The holder 341 may be adjusted vertically relative to the bracket 287 by an adjusting screw 343 and may be clamped in adjusted position thereon by a clamping screw 344. A truing tool (not shown) may then be positioned in the hole 345 formed in the holder 341. The speed of the regulating wheel 191 is then increased to a suitable speed for a truing operation after which the slide 253 may be traversed longitudinally to traverse the truing tool across the peripheral face thereof to true the same. The regulating wheel 191 may be advanced toward the truing by actuation of the feed wheel 199 to facilitate truing the desired amount from the peripheral surface thereof. The truing tool for the regulating wheel is identical with the truing tool 307 but must be removed from the supporting hole 345 in the holder 341 during grinding.

In a straight-through grinding operation, it may be desirable to provide a slight taper 346 on the periphery of the grinding wheel 34 adjacent to the work entrance position (Fig. 20). This is preferably accomplished by providing a template or forming bar 347 which is adjustably mounted on the upper surface of the bracket 287. The

bar 347 is pivotally supported by a vertical pivot screw 343 supported on the bracket 287. A clamping screw 349 passes through a clearance hole in the bar 347 and is screw threaded into the bracket 287 to facilitate clamping the bar 347 in adjusted position on the bracket 287. An adjustable screw 350 mounted on top of the bracket 281 serves as a follower along which the bar 34 7 traverses. The bar 347 traversing across the fixed follower screw 350 imparts "a swinging movement to the bracket 287 as it is traversed along so as to impart a controlled transverse movement to the truing tool 307. The bar 347 is swivelled to the desired extent and screws 293 and follower screw 350 adjusted so that during the initial traversing movement of the truing tool 307, the bar 347 imparts a transverse movement to truing tool 307 to true a taper face 346 on a grinding wheel. This continues until the stop screw 293 engages surface 294 to hold truing tool 307 against further transverse movement after which continued longitudinal traversing movement of the truing tool 307 trues a cylindrical face 34611 on the remainder of the operative face of the grinding wheel 34 (Fig. 20). In case a taper face 346 is not desired, the follower screw 350 may be adjusted relative to the bracket 281 so that its end face is out of engagement with the bar 347.

A traversing mechanism is provided for the slide 253 to facilitate traversing the truing tool 307 or the regulating truing tool across the operative face of the grinding wheel 34. This mechanism comprises a cylinder 315 fixedly mounted relative to slide plate 252. The cylinder 315 contains a slidable piston 316 which is connected to the left hand end of a piston rod 317 (Figs. 17 and 37). The right hand end of the piston rod 317 is fixedly connected to the right hand end of the slide 253.

When fluid under pressure is passed through the pipe 318 into a cylinder chamber 319, the piston 316 together with the slide 253 are moved toward the right to traverse the truing tool 307 toward the right across the face of the grinding wheel 34 to true the same. During this movement fluid within a cylinder chamber 320 may exhaust through a'pipe 321. A throttle valve 322 and a ball check valve 323 are provided in the pipe line 318. A throttle valve 324 is provided in the pipe line 321. These valves serve to control the rate of the traversing movement of the slide 253 and the truing tool 307.

A control valve 325 is provided for controlling the admission to and exhaust of fluid from the cylinder 315 and also the feed compensating cylinder 115. The valve 325 is a piston-type valve having a slidably mounted valve member 326. A plurality of spaced valve pistons are formed integral with the valve member 326 .to form a plurality of spaced valve chambers 327, 328 and 329. The member 326 is also provided with a central passage 330 which connects the valve chamber 327 with the valve chamber 329. A compression spring .331. is provided normally to hold the valve member 326 in a left hand end position. A solenoid S5 is provided which when energized serves to shift the valve member 326 into a right hand end position. In the position of the valve 325 (Fig. 37), fluid under pressure from the pressure pipe 153 enters the valve chamber 328 and passes through the pipe 321, through the throttle valve 324 into the cylinder

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