US2142050A

US2142050A - Crankshaft grinding machine

Info

Publication number: US2142050A
Application number: US133222A
Authority: US
Inventors: John I Garside; Carl G Flygare
Original assignee: Norton Co
Current assignee: Saint Gobain Abrasives Inc
Priority date: 1937-03-26
Filing date: 1937-03-26
Publication date: 1938-12-27
Anticipated expiration: 1955-12-27

Description

Dec. 27, 1938. J. GARS!DE ET AL CRANKSHAFT GRINDING MACHINE Filed March 26, 1957 6 Sheets-Sheet 1 JUHN lEHRs/uE Cam 5'. F LYGHR'E Mum-m.

Dec 27, 1938. .1. I. GARSIDE ET AL CRANKSHAFT GRINDING MACHINE Filed,March 26, 1937 6 Sheets-Sheet 2 M E w mm% m 9% gm w H N QM 355.. MW NL UH JE w {GM 3N QM @N h khh NNN Dec. 27, 1938. J. l. GARSIDE ET AL 2,142,050

CRANKSHAFT GRINDING MACHINE Filed March 26, 1957 6 Sheets-Sheet 3 Jul-IN I. E'F/RS/UE EHRL E F L YEP/RE 1938- J. GARSIDE ET AL 2,142,050

CRANKSHAFT GRINDING MACHINE Filed March 26, 1937 6 Sheets-Sheet 4 3mm JD'HN I EHRS/UE EFIRL 5. FLYQHRE 1933- J. l. GARSIDE ET AL 0 CRANKSHAFT' GRINDING MACHINE Filed March 26, 1937 6 Sheets-Sheet 6 2/3 I I I I, I

Patented Dec. 2' 7, 1938 UNITED STATES PATENT OFFICE.

2,142,050 CRANKSHAFT GRINDING MACHINE Application March 26, 1937, Serial No. 133,222

17 Claims.

The invention relates to grinding machines, and more particularly to a machine for grinding cylindrical surfaces, such as crankshafts.

One object of the invention is to provide a simple, thoroughly practical grinding machine construction. Another object of the invention is to provide an improved electrical control mechanism for a grinding machine. Another object of the invention is to provide a grinding machine having an electrically actuated tabletraversing mechanism. Another object of the invention is to provide a grinding machine having an electrically actuated grinding wheel traversing mechanism. Another object of the invention is to provide an improved grinding machine and control mechanism therefor in which the work table traversing mechanism, the wheel head traversing mechanism, the work rotating mechanism and the grinding wheel driving mechanism are all electrically controlled.

A further object of the invention is to provide a single control lever for controlling the longitudinal traversing movement of the table when moi ed in one direction and to control the transverse movement of the grinding wheel head when moved in another direction. A further object of the invention is to provide an improved interlock control mechanism for an electrically actuated table traverse mechanism and an electrically actuated wheel head traversing mechanism. Annother object of the invention is to provide an interlocked electrical control mechanism whereby the rotation of the work, longitudinal traverse of the work table, transverse traverse of the grindingwheel slide and the movement of the work steady rest are all interlocked. Other objects will be in part obvious or inpartpointed out hereinafter.

The invention accordingly consists in the fea- 40 tures of construction, combinations of elements,

' and arrangements of parts, as will be exemplified in the structure to be hereinafter described. and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

. Fig. 1 is a front elevation of the improved 50 grinding machine, having parts broken. away and shown in section more clearly to show the opcrating construction;

Fig. 2 is a right-hand end elevation, on an enlarged scale, of the improved crankpin grinding 55 machine;

Fig. 3 is an electrical wiring diagram of the electrical control units of the machine;

Fig. 4 is a fragmentary rear elevation, on an enlarged scale, showing the wheel slide construction and the operating mechanism therefor;

' Fig. 5 is a fragmentary plan view of the limit switch assembly and operating dogs for the wheel slide;

Fig. 6 is a side elevation of the limit switches and dogs for controlling the same, as shown in Fig. 5;

Fig. '7 is a fragmentary vertical sectional view, taken approximately on the line l--'l of Fig. 4, showing the two-speed traversing mechanism for traversing the wheel slide;

Fig. 8 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 8--B of Fig. 2, through the control lever mechanism for the table and wheel units;

Fig. 9 is a fragmentary cross sectional view, taken approximately on the line 9-9 of Fig. 8; Fig. 10 is a fragmentary cross sectional view, taken approximately on the line I0l0 of Fig. 8; Fig. 11 is a vertical sectional view through the control lever mechanism, taken approximately on the line H-ll of Fig. 8;

Fig. 12 is a fragmentary sectional view, taken approximately on the line l2-l2 of Fig. 11;

Fig. 13 is a horizontal sectional view, taken approximately on the line l3l3 of Fig. 12;

Fig. 14 is a fragmentary perspective phantom view of the electrically driven table traversing mechanism;

Fig. 15 is a fragmentary sectional view, on an enlarged scale, through the work steadying rest, taken approximately on the line I5-i5 of Fig. 1;

Fig. 16 is a fragmentary vertical section through a portion of the steadyrest, take'n approximately on the line l6-l6 of Fig. 15; and.

Fig. 17 is a fragmentary detail view of the cam and limitswitch on the left-hand side of-the steadyrest.

An improved grinding machine embodying this invention has been illustrated in. the drawings, comprising a base 20 which supports a longitudi- .nally movable work supporting table 2| which is arranged to slide longitudinally on a V-way 22 and a fiat way 23 on the base 20. The work supporting table 2| supports a pair of opposed work supporting and rotating

heads

24 and 25, each of which supports a rotatable work supporting spindle 2B and 21 carrying work holders 28 and 29, respectively; The work holders 28 and 29 are provided with work clamps 30 and 3| by which a work piece such as a crankshaft to be ground ton No. 1,563,310 dated November 24, 1925, to

16-58 and 41-5l,

which reference may be had for a more complete disclosure of the work clamping mechanism.

The work spindles 26 and 21 are arranged so that they may be rotated in synchronism to rotate the opposite ends of a work piece, such as a crankshaft 285. An-electric motor is adjustably mounted on the table 2| and is provided with a driving pulley 36 which is connected by a driving belt, such as multiple V-belts 31, with a pulley 38 which is mounted on the end of a shaft 39. The shaft 39 is journalled in a bearing 48 which is supported on the work head 24. The other end of the shaft '39 is provided with a splined portion 4| which meshes with an internally splined portion 42 in a rotatable hollow shaft 43. The shaft 43 is journalled in bearings 44 and 45 carried by the

work supporting heads

24 and 25, respectively. The hollow shaft 43 is provided with pulleys 46 and 41 which are slidably keyed to the hollow shaft 43 so as to facilitate longitudinal adjustment of the

work heads

24 and 25, respectively. The pulleys 46 and 41 are connected by

driving belts

48 and 49 with pulleys 58 and 5|, respectively, which are mounted on work rotating spindles 26 and 21. The

driving belts

48 and 49 are preferably of the multiple V-belt type comprising a plurality of driving belts of V-shaped cross-sectional area which ride upon multiple grooves in the pulleys respectively. By providing a drive as above described, a uniform driving torque is synchronously applied to each end of the work piece or crankshaft to be ground.

To'facilitate grinding of crankshafts of different lengths, the

work heads

24 and 25 are arranged to slide longitudinally on guiding and supporting surfaces 52 on the top of the work supporting table 2|. The head 24 is provided with clamping members 53 and 54 and the head 25 is provided with clamping members 55 and 56. by means of which the heads may be locked in adjusted position on the table 2|.

A rotatable grinding wheel 68 is mounted on the outer end of a wheel spindle 6| which is rotatably journaled in a transversely movable wheel slide 62. The other end of the wheel spindle 6| is provided with a driving pulley 63 which is connected by multiple V-belts 64 with a pulley 65-mounted on the outer end of a motor armature shaft 66 carried by an electric driving motor 61 which is mountedfon the upper surface of the wheel slide 62. The Wheel slide 62 is preferably supported on a transversely movable intermediate slide 68. The wheel slide 62 is supported on a transversely extending V-way 69 and a flat way 18 on the intermediate "slide 68. The intermediate slide 68 is in turn supported on a V-way 1| and a flat way 12 on the base 28 (Fig. 4).

The wheel slide 62 is arranged to be moved transversely on the intermediate slide 68 by a power operated mechanism, to be hereinafter described, to move the wheel rapidly toward or from an operating position with relation to the work piece. The wheel 68 is arranged so that it may be manually fed into the work piece to grind the same to the required and predetermined size. This mechanism may comprise a manually operable wheel feeding mechanism of the type shown in the expired United States patent to C. H. Norton No. 762,838 dated June 14, 1904, to which reference may be had for a detailed disclosure thereof. The intermediate slide 68 is provided with a depending half nut 15 which meshes with or engages a rotatable cross feed screw 16 which is rotatably supported in suitable bearings (not shown) in the base 28. The feed screw 16 is connected to or formed integral with a shaft 11 which projects from the front of the machine base and is operatively -connected to be rotated by a manually operable feeding wheel 18.

The wheel slide 62 is provided with a power operated traversing mechanism which is arranged to move the slide first at a rapid rate to cause the grinding wheel 68 to approach the work piece and then to reduce the approaching speed to a proper speed for grinding the checks or end faces adjacent to a crankpin, if desired. In the preferred form, an electric motor driven driving mechanism is provided for moving the wheel slide 62 transversely relative to the intermediate slide 68 and the base 28. This mechanism comprises an electric motor 88 supported on a bracket 8| on the intermediate slide 68. The motor 88 is provided with a driving pulley 82 which is connected by a driving belt 83 with a pulley 84 mounted on the outer end of a rotatable shaft 85. The shaft 85 is journaled in a boss 86 projecting outwardly from a gear casing 81 which is fixed to the intermediate slide 68. The inner end of the shaft 85 is provided with a gear 88 which meshes with a gear 89 supported on a shaft 98 which is rotatably journaled in bearings (not shown) in the casing 81. The gear .88 also meshes with a gear 9| supported on a rotatable shaft 92 which is also mounted in bearings (not shown) in the casing 81. The shaft 98 supports a spiral gear 94 which is keyed thereon to rotate therewith. The spiral gear 94 meshes with a spiral gear 95 rotatably supported on a shaft 96 which is supported in

bearings

91 and 98, respectively, in the casing 81. The gear 95 is free to rotate on the shaft 96 when driven by the spiral gear 94. The shaft 92 is provided with a worm 99 meshing with a worm gear I88 which is rotatably supported on the shaft 96. In order to transmit a rotary motion to the shaft 96. a movable clutch member I 8| is slidably keyed thereto and is provided with clutch teeth at its opposite ends which are arranged to engage clutch teeth formed on the inner surface of the gear 95 or to engage a set of clutch teeth on the inner face of the worm gear I 88 so that either the spiral gear 95 or the worm gear I88 may be locked by the clutch member IM to rotate the shaft 98, either at a fast or a slow speed, as desired.

In order to shift the clutch member III, a yoked member- I82 is pivotally mounted on a stud I83 carried by the casing 81. An upwardly extending arm I84 is also supported on the stud I83 and is'connected to move the yoked member I82. A spring I85 is connected between a stud I86 carried by the casing 81 and a stud |81 carried by the arm I84 and serves normally to hold the clutch member I8I in engagement with the clutch teeth on the worm gear |88 to rotate the shaft 96 at a comparatively slow rate. In order to shift the clutch member |8| into engagement with the gear 95 to rotate the shaft 96 at a comparatively rapid rate, an electric solenoid I08- is provided and supported on a bracket I09 which is fixed to or integral with the casing 81. The armature IIO of the solenoid I08 is connected by a screw III and a stud II2 with the upper" end of the arm I04 and is arranged so that when the solenoid is energized, the arm I04 and yoke I02 are rocked in a clockwise direction (Fig. 7) to shift the clutch member IOI into engagement with the clutch teeth on the gear 95 to rotate the shaft 96 at a comparatively rapid rate.

The outer end of the shaft 96 is provided with a sprocket II5 which is connected by a link chain II6 with a sprocket II1 mounted on the outer end of a rotatable feed screw II8 which is journaled in suitable bearings (not shown) in the intermediate slide 68. A half nut 9 depends from the wheel slide 62 and engages or meshes with the feed screw 8 so that when the feed screw H8 is rotated by the gear mechanism above described, the wheel slide 62 will be moved transversely to cause the wheel '60 to approach or recede from the work piece being ground either at a fast or at a slow speed. In order to maintain.

To. facilitate an interlocking of the various mechanisms of the machine and controlling the electrical circuits therefor, a series of electrical switches, such as limit switches I30, I3I, I32 and I33 are mounted on the upper surface of the casing 81 which is carried by the intermediate slide 66. A plate I35'fixed to the wheel slide 62 carries a plurality of adjustable dog bars which are arranged to "engage and actuate'the normally closed limit switches I30, I3I, I32 and I33. The limit switches and dogs are staggered and spaced from each other so that they may be operated at the desired time during the movement of the wheel slide 62 toward and from the work piece. An adjustable dog I36 is adjustably mounted on the plate I35 by means of a screw I31 which passes through an elongated slot I38 in the plate I35. The dog I36 is arranged to engage and actuate the normally closed limit switch I33; A dog bar or plate I39 is adjustably secured to the plate I35 by means of a screw I40 passing through an elongated slot MI. The dog bar or plate I39 is arranged in the path of the limit switch I32 so as to actuate the switch in the desired timed relationship with the movement of the wheel slide 62. A dog I42 is adjustably secured to the plate I35 by means of a screw I43 which passes through an elongated slot I44 to facilitate adjustment of the dog I42 relative to the limit switch I3I so as to actuate the same in the desired time during the movement of the wheel slide 62. A similar dog I45 is held in adjusted position on the plate I35 by means of a screw I46 which passes through an elongated slot I41. The dog I45 is arranged in the path of the limit switch I30 so as to actuate the switch 'when the wheel slide 62 is moved. The operation of the limit switches above described, together with their inter-connection with rear of the base 20 of the machine.

the various mechanisms of the machine, will be described hereinafter.

The work table 2| is arranged so that it may be traversed either manually or by power. A manually operable traverse mechanism isprovided including a manually operable hand wheel I which is connected through a gear mechanism (not shown) with a rack bar I56 depending from the table ill. The manually operable traverse mechanism is not considered to be part of the present invention and consequently has not been illustrated in detail. This mechanism may be arranged substantially as shown in the prior expired patent to Norton No. 762,838 dated June 14, 1904, to which reference may be had for a more detailed disclosure of the manual traverse mechanism.

Power traverse-work table "traversed rapidly to position various portions of the crankshaft 205 in operative relation with the grinding wheel 60, or moved at a relatively slow rate in either direction for truing the grinding wheel 60. An electrically driven mechanism is provided comprisinga reversible electric motor I51 (Figs. 2, 8 and 14) which is supported on the An armature shaft I58 (Fig. 14) of the motor is provided with a pulley I59 which is connected by adriving belt I60 with a pulley I 6| mounted on the end of a rotatable shaft I62. A gear I63 is either fixed to or formed integral with the shaft I62. A movable clutch member I64 is slidably keyed to a rotatable shaft I 65. The clutch member I64 is arranged so that it may be moved by means of a yoked member I66 which is mounted on one end Rapid table traverse The other end of the shaft I carries a gear I15 which meshes with a gear I 16 supported on the end of a rotatable shaft I11. The shaft I11 carries a worm I18 meshing with a worm wheel I19which is rotatably mounted on a'shaft |80.'

The shaft I80 carries a gear |8I meshing with a gear I82 which is rotatably supported on a shaft I83. The shaft I83 supports a gear I84 which meshes with a large gear I85 mounted on the end of a shaft I86. The shaft I86 is provided with a driving pinion I81 which meshes with the rack bar I56 depending from the table 2|, so that when the clutch member I 64 is thrown into engagement with the clutch teeth I10, the rotary motion transmitted from the reversible electric motor I51 is'transmitted through the gear mechanism, above described, to the rack bar I56 to traverse the table 2| longitudinally at a relatively v rapid rate.

Slow table traverse ries a worm 299 which meshes with a worm gear 23Irotatably supported on the shaft I65. The gear MI is provided with clutch teeth 292 which are arranged to be engaged by the movable clutch member I64. When a slow traverse of the table 2I is desired, the yoked member I66 is rocked in a clockwise direction to move the clutch member I64 toward the left (Fig. 14) so that it engages the clutch teeth 292 carried by the gear 29I. Power from the reversible motor I51 is then transmitted through the gear I63, the gear I95, the shaft I96, the worm I91, the worm gear I98, the shaft I99, the worm 299, the worm gear 29I, the clutch teeth 292, to rotate the clutch member I64 and the shaft I65 to transmit a rotary motion to the gear mechanism I15 to I81 inclusive to transmit a slow traversing movement to the rack bar I56 and the table 2 I.

steadyrest The work piece, such as the crankpin 295 being ground, is preferably steadied by a steadyrest 296 having a downwardly extending frame 291 which is fixedly mounted on the front of the machine base 29. The steadyrest frame 296 is arranged to support a movable steadyrest slide 299 which may be moved into and out of an operative position by means of a handle 299. The slide 298 carries a pivotally mounted steadyrest shoe 2I9 which is arranged to engage the under side of the work piece 295 at a point adjacent to the line of contact between the work piece 295 and the operative face of the grinding wheel 69. The frame 298 also supports a horizontally movable steadyrest shoe 2 which is arranged to engage the workpiece at a point diametrically opposite the line of contact between the grinding wheel 69 and the work piece 295.

The lower steadyrest shoe 2I9 is pivotally mounted on a stud 2" carried by the slide 298.

The steadyrest shoe 2 I9 is held in an upward position by means of a link 2 I3 which is connected by a stud 2 I4 with the shoe carrying member and is connected by a stud 2I5 with a slide block 2I6 which is actuated by a rod 2". The rod 2 I1 may be precisely adjusted to maintain the steadyrest shoe 2 I 9 in supporting engagement with the work by means of a knob 2 I8 which is threaded onto a screw threaded portion 2I9 of the rod 2I1. To facilitate rapid removal of the lower shoe 2I9 from engagement with the work, a quick acting sleeve 229 supports the outer end of the rod 2 and is arranged so that when rotated by a handle 22I through a quarter turn, it may-be'rapidly withdrawn toward the left Fig. 15) rapidly to slide the rod 2I1 and drop the work steadying shoe from operative engagement with thework piece 295. The work steadying shoe 2I I is carried by a transversely movable slide 225 which is supported in the slide 293 and is adjusted relatiive thereto by means of a nut 226 and a screw 2 1.

The steadyrest slide 299 is arranged so that it may be rapidly moved to and from an operating position. As illustrated in Fig. 15, a spring pressed locating plunger 239 engages a locating aperture in the under side of the slide 298 and serves to hold the slide in an operating position during a grinding operation. When it is desired to traverse the table 2| or to remove a work piece 295 from the machine, the locating plunger 239 may be rapidly withdrawn from the notch in the slide 298 by raising the lever 23I and then pulling the handle 299 to withdraw the steadyrest to an inoperative position.

In the present machine, the work rest is of a massive construction and requires considerable effort on the part of the operator manually to withdraw the same by means of the handle 2. To facilitate movement of the steadyrest to an inoperative position, a rack and gear mechanism outer end of the shaft 231 and is arranged so that by manipulation of the lever 238, the steadyrest slide 298 may be readily moved to and from an operative position without undue exertion on the part of the operator.

Interlock-steadyrest and table traverse It is desirable in a machine of this type to provide suitable interlocks between the various mechanisms of the machine to insure safe operation thereof. It is desirable to provide an interlock between the steadyrest and the table traverse 'mechanism which is so' arranged that the table 2I cannot be traversed when the steadyrest is in a forward or operating position. To accomplish this result, a normally open limit switch 249 is mounted on a bracket 2 on the left-hand side of the steadyrest casing (Fig. 16). When the steadyrest is in a forward position, as indicated in Fig. 16, the limit switch 249 remains open, thereby causing a break in a circuit which controls the table traverse mechanism, so that the table movement cannot be started. A cam 242 is mounted on the end of the shaft 231 and is arranged so that when the lever 238 controlling the movement of the steadyrest is turned to withdraw the steadyrest to an inoperative position, the cam 249 swings into the position illustrated in Fig. 17 to close the limit switch 249 so that the table may then be traversed by manipulation of the table traverse control lever. This mechanism serves to prevent accidental starting of the table traverse when the work steadyrest and shoes are in an operating position between the crank arms of a crankshaft 295.

Interlock-work rotation and steadyrest It is also desirable to provide an interlock'between the work rotation and the steadyrest, so that the work piece or crankshaft cannot be rotated unless the steadyrest is in a forward or op-' erating position. A limit switch 245 is mounted within the steadyrest casing 291. The roller 246 of the limit switch. 2451s arranged in the path "of ahead 241 on the lower end'of the locating plunger 239, so that when the lever 23I is lifted to withdraw the locating plunger 239 so that the rest may be withdrawn to an inoperative position, the head 241 of the plunger 239 engages the limit switch roller 246 and opens the limit switch 24!. thereby breaking a circuit to the headstock or work driving motor to prevent rotation thereof during the time the rest is in a rearward or inoperative position.

Main control lever It is desirable to provide a single main control lever which is operatively connected and arranged so that when the lever is moved into various control positions, the movement of the table may be controlled to traverse the table in either direction at a comparatively rapid rate to position the work piece in operative relation with the grinding wheel or may be moved at a slow grinding wheel. A main control lever 258 is slidably and rotatably mounted within a sleeve 25I (Figs. 8 and 11) which is pivotally supported on a yoked member 252 by means of a stud 253 .which passes through the two arms of the yoke 252 and through an enlarged portion of the sleeve 25L This pivotal connection serves to permit the control lever 258 to be rocked toward and bearing 26I in the sleeve 25I.

from the machine. The yoked member 252 is provided with a horizontally extending stud or trunnion 254 (Fig. 11) which is journalled in a bearing 255 so that the lever 258 may be rocked sideways in either direction. The bearing 255 is formed as an integral part of a control apron 256 which is fastened to the front of the machine base 28. A cover plate 251 on the apron 256 is provided with an H-shaped opening 258 (Fig. 10) which serves to control the in and out and sidewise movement of the control lever 258.

The control lever 258 comprises a central rod 268, the lower end of which is supported in a A sleeve 262 surrounds the upper portion of the rod 268 and is supported in a. bearing 263 carried by the sleeve.

25I. A spring 264 surrounds the rod 268 and is contained within an enlarged aperture within the sleeve 25I and is interposed between a shoulder at the bottom of the enlarged hole within the sleeve 25I and the-end of the sleeve 262 and serves normally to hold the sleeve 262 and rod 26 in its uppermost position. The lever 258 has been shown in its central or neutral position (Figs. 8, 10 and 11) The sleeve 25I is provided with two rearwardly extending

lugs

266 and 261 which support a rod 268. The yoked member 269 is supported by a pair of slidably mounted rods 2H and 212 (Figs. 11 and 12) which are slidably supported in bearings 213 and 21.4 in the apron 256. The slide rods 2H and 212 serve to support a member 215 having a track cam 216 formed in its lower surface. The member 215 is mounted and supported on the base slide rods 2H and 212 and has its opposite ends slotted and provided with-clamping screws 280 and 28I by means of which the member 215 may be clamped in adjusted position on the rods 21I and 212. 'A follower 282 (Figs. 11 and 12) engages the cam track 216 and is formed on the upper end of a lever 283 supported on one end of a rotatable shaft 284 which is journaled in a bearlng member 285 in the apron 255. The other end of the shaft 284 is provided with a downwardly extending lever 286 which is connected by a stud 281 with a yoked end 288 of the connecting link I69 which is connected to actuate the clutch member I64.

When the control lever 2581s moved in a clockwise direction (Fig. 11) about the pivot 253 into position 2580 (Figz 10), the rod 268, yoke member 269 and

rods

218 and 2" serve to move the cam member 215 toward the right (Fig. 11) which 7 In turn serves to rock the follower 282 and the 'flie electric motor I51 is a reversible type motor which is controlled by a reverse starter switch 298 which is mounted within the apron 256. The pivotally mounted trunnion or stud 255 supports a downwardly extending lever 29I (Fig. 11) which is provided with a yoked portion 292 at its lower 'end. The yoked portion 292 straddles a pin or stud 293 which is carried at the lower end of a lever 294. The lever 294 is mounted on a rotary shaft 295 which actuates the reverse starter switch 298. The reversing switch 298 operates through a magnetic starter reversing switch 296 (Fig. 3) to control the rotation of the motor I51 and thereby to control the direction of movement of the work supporting table 2|. When the control lever 258 is moved from position 258e/into position 2581), the control lever is rocked in a counterclockwisedirection (Fig. 8) whichserves through the trunnion 255 and lever 29I to shift the reversin switch 298 from a central or neutral position to operate through the starter switch 296 to start the motor I51 rotating in one direction to transmit a corresponding traversing movement to the table 2| toward the left. If it is desired to move the table in the reverse direction, the control lever 258 may be shifted from position 2581) into position 258e, which operates to shift the reversing switch 298 into a. reverse position, thereby shifting the magnetic starter switch 296 to reverse the flow of current to the motor I51 and to start the table traversing toward the right.

When it'is desired to move the table at a slow rate in either direction for truing the grinding wheel, the control lever 258 is moved into position 258d which serves through the rod 268 (Fig. 11), the yoke 269, the rods 2H and 212, and the cam .member 215, to shift the

levers

283 and 286 and thereby shift the clutch member I64 into engagement with the clutch teeth 282, so that power from the motor I51 is transmitted through the slow speed gearing above described to traverse the table 2I at a comparatively slow rate of speed. The movement of the control lever 258 from position 258d-into position 258e serves to actuate the reversing switch 298 to start the table traversing slowly in a direction toward the left. Similarly, movement of the control lever 258 from position 258e or 258d into position 258! serves to start the table moving slowly in a direction toward the right. It. will be readily apparent from the foregoing disclosure that by shifting the control lever 258 within the H-shap ed aperture 258, the work supporting table 2| may be traversed in either direction, either at a comparatively fast or at a comparatively slow rate of speed. The direction of movement of the lever 258 within the H-shaped slot determines the direction and speed of movement of the table. The lever 258 is moved in the direction it is desired to traverse the table.

Wheel feed control It is desirable to provide a suitable mechanical interlock between the electrical table traverse andtheelectrical wheel slide movements so that the table cannot 'be traversed when the wheel slide is being moved. It is, therefore, desirable to provide a further control movement of the lever 258 to operate the wheel feeding movement and at the same time prevent movement of the table 2i. This is preferably accomplished when the control lever is in the center part of the H-shaped slot in the cover plate 251.

In order to control the infeeding movement of the grinding wheel 68, a. reversing switch 388 (Fig. 11) is mounted within the apron 256 and is connected through a magnetic reverse starter switch 30| to control the wheel slide motor 80 to cause either a forward or rearward movement of the wheel slide 62. The reversing switch 300 is provided with a control shaft 302. A gear segment 303 is mounted on the upper end of the shaft 302 and meshes with a gear segment 304 which is formed integral with a rotatable stud 305 which isjournaled in a bearing 306 in the apron 256. The stud 305 is provided with a central aperture 301 and its upper surface is provided with a transversely extending slot 308 (Figs. 8, 9 and 11).

The lower end of the sleeve 25| supports a bushing 3I0which is'lkeyed thereto and clamped in place therein by means of a clamping screw 3 which passes through a pair of opposed lugs 3I2 in a split portion formed at the lower end of the sleeve 25I. The bushing 3l0 is provided with a pair of downwardly extending portions 3I3 and 3I4 (Fig. 8) which serve as a guide normally to prevent rotation of an elongated key member 3I5formed integral with the lower end of the rod 260. A stud 3I6 is also formed integral with the key member 3| 5 and the rod 260.

When the control lever 250 is in a central position 250 within the H-shaped slot 258 (Fig. 10), a feeding movement of the wheel slide maybe obtained by pushing downwardly on the control lever 250 against the tension of the spring 264. This movement serves to move the stud 3I6 downwardly into engagement with the hole 301 in the rotatable stud 305 and also serves to move the key member 3|5 downwardly into engagement with the transversely extending slot 308 in the gear segment member 304. In this position of the parts, the control lever 250 and rod 260 may be rotated by means of a crank arm 3| 1. Movement of the crank arm 3I| serves through the key 3I5 to move the gear-segment 304, which transmits a corresponding movement of the gear segment 303 to shift the reversing switch 300, which operates through the magnetic starter reversing switch 30| to control the motor 80 to cause either a forward or rearward movement of the wheel slide '62. The reversing switch 300 is preferably arranged so that the wheel slide 62 will be moved in the direction in which the crank arm 3|! is moved,

that is, when the crank arm 3" is moved toward the rear of the machine, the wheel slide 62 will be moved rearwardly, or when the crank arm 3| 1 is moved forwardlytoward the operator, the wheel slide 62 and motor 80 will be rotated to cause a forward approaching movement of the grinding wheel and the wheel slide 62. The stud '3 I6 engaging the hole 301 during the movement of the wheel slide 62 prevents the lever 250 from being shifted from its central position, thereby locking the control lever 250 so as to prevent a traversing movement of the table during the forward or rearward movement of the wheel slide 62.

During the normal operation of the machine, the limit switch I32 which is supported on the intermediate wheel slide 68 serves to prevent table traverse when the wheel slide 62 is in a forward position. wheel 60 may be trued when desired, it is desirable to provide a means for allowing a slow traversing movement of the work table when the wheel slide is in its forward position. To accomplish this result, a normally open limit switch 320 is mounted within the apron 256 and is connected in parallel with the limit switch I32. The switch 320 has a roller 32| which is arranged in the path of a cm 322 formed on the upper sur- In order that the grinding face of the slide block 215 so that when the block 215 is moved toward the left (Fig. 11) as the control lever 250 is moved forward into a low speed position, the normally open limit switch 320 is closed, thereby closing the circuit (while the limit switch |32 remains open) so that the wheel slide 62 will remain in the forward position dur-,

member IOI into a slow speed position to cause a slow forward advancing movement of the grinding wheel. The slow power infeed of the grinding wheel is preferably of a suitable rate for the grinding of the cheeks adjacent to the ends of a crankpin.

The slow power infeed of the wheel slide 62 continues until the dog I36 actuates the limit switch I33, thereby breaking the circuit which serves through the magnetic switch 30I to stop the rotation of the wheel feed motor 80. The dog I36 is preferably so adjusted that slow power infeed is stopped just before the periphery of the grinding wheel 60 engages the cylindrical body of the crankpin to be ground. The body or cylindrical pin may then be ground by manually advancing the grinding wheel 60 by rotation of the manually operable feed wheel 18. The crankpin may be accurately ground to a predetermined size by manipulation of the manually operable feed wheel.

After a grinding operation has been completed, it is desirable to provide a suitable control so that the grinding wheel slide 62 may be moved rapidly to its rearward position. This is preferably accomplished by means of a normally open limit switch 325 mounted within the con-, trol apron 256 and connected in parallel with the limit switch I3I to actuate the solenoid I06.

The limit switch 325 is provided with an actuating roller 326 arranged in the path of a cam surface .321 formed integral with the gear segment 304.

The limit switch 325, which is normally open, is shunted acrossthe circuit so that when the lever 3|? is moved rearwardly to shift the reversing switch 300 to reverse the direction of rotation of the motor 80 to cause a rearward movement of the wheel slide 62, the solenoid I08 is energized instantaneously to shift the clutch member I0| into a high speed position rapidly to withdraw the ,wheel slide 62 and grinding wheel 60 to an inoperative position.

It is desirable to provide a control mechanism to prevent the table 2| traversing beyond the desired extent to prevent the work supporting heads 23 and "from being traversed into the grinding wheel. A pair of limit switches 329 and 330 (Fig.

3) are mounted on the front of the steadyrest frame 206 within a casing 33I (Fig. 15) and are provided with

actuating rods

332 and 333 which are arranged to be engaged by

lugs

334 and 335 carried by the work heads 24 and 25, respectively.- The limit switches 329 and 330 are normally closed and are connected so that when the rod 332 or the rod 333 engages the lug 334 or the lug 335, respectively, to open one or the other of the limit switches 328 or 330, it breaks the circuit, thereby to open the magnetic starter switch 286 to stop the rotation of the table traverse motor I51 before the wheel 69 engages either of the work supporting heads 28 or 29.

Electrical control station The electrical wiring diagram has been illustrated in Fig. 3, showing the electrical diagram for controlling the various operating units on the machine. It is desirable to provide a central control station whereby the various operating. .units on the machine may be readily controlled within easy reach of the operator. A series of control push buttons ,are preferably mounted on the side of the steadyrest casing within easy reach of the operator. Referring now to Figs. 2 and 3, a push button control 336 is arranged to control the stopping and starting of the wheel rotating motor 61. when the push button 331 is pushed in, a circuit is made to operate a magnetic starter switch 338 to start the rotation of the-motor 61. Similarly, pushing in on the button 339 serves to break the circuit, thereby operating the magnetic switch 338 to stop the rotation of the wheel driving motor 61. A push button switch 349 serves to control a ni'agnetic switch -34I to stop and start a motor 342 for rotating a coolant fluid pump (not shown). Pushing in on a button 343 serves tooperate the magnetic switch 3 to stop the rotation of the motor 342. Similarly, pushing in 'on the button 344 serves through the magnetic starter switch to start the rotation of the coolant fluid motor 342.

A push button switch 345 having a push button 346 serves as a jogging switch to operate through the magnetic switch 296 to inch or jog the motor I51 to cause the table 2I to move longitudinally by short increments. This switch serves instantaneously to close the magnetic switch 296, which serves to traverse the table through a very small extent to position the work piece in operative relation with the grinding wheel 69. A push button switch 341 having a stop push button 348, an inch or jog button 349, and a run button 359 serves to control the rotation of the motor 35 for rotating the work head and crankshaft being ground. Pushing in on the stop button 348 serves to open a circuit, deenergizing a work stop solenoid 35I, which operates through a trip! switch 352 and a magnetic switch 353 to stop the rotation of the motor 35. The work stop control mechanism for stopping the rotation of the motor 35 so that the work heads are always in an upright or vertical position is not considered part of the present invention, consequently the details of construction and the controls have not been illustrated.

The work rotation motor 35 may be jogged or inched, if desired, by pushing the button 349 which operates through a solenoid relay 354 instantaneously to operate the magnetic switch 353 to inch or jog the rotation of the motor 35 and the work supporting heads 39 and 3I, respectively. Pushing in on the button 359 closes a circuit and operates through the solenoid switch 354 to operate the magnetic switch 353 andcontinuouslyrotate the motor 35 and the work isupporting heads 39 and 3| vduring the grinding operation.

It will be readily apparent from the foregoing description of the controls that the operator may, from'a single position in front of the machine, actuate not only the main control lever but alsocontrol the starting and stopping of jogging of the various motors on the machine.

The operation of this machine will be readily apparent from the foregoing disclosure. A work piecasuch as a crankshaft 295, is placed in position on the work heads 28 and 29 and clamped in position thereon by the clamping members 39 and 3|, respectively. The steadyrest lever 238 is then pushed forward to position the steadyrest slide 298 in an operating position with the 10- cating plunger 239 in the position as illustrated in Fig. 15. The control lever 259 is then moved in a clockwise direction (Fig. 11) into position 259a (Fig. 19) and then shifted either into position 259!) or 259c'to move the table 2| longitudinally to position a crankpin in operative position opposite the operative face of the grinding wheel 69. When the crankpin reaches a predetermined position, the control lever 259 is shifted from position 259b or 2590 through the position 259a into position 259, as shown in Figs. 8, 10 and 11. The operator then pushes the button 33'! to startthe rotation of the motor 61 and the grinding wheel 69 and then pushes the button 359 to start rotation of the work drive motor 35 synchronously to rotate the work supporting heads 28 and 29 and the crankshaft 295. The lever 259 is then pushed downwardly so that the stud 3I6 engages the hole 391 in the rotatable stud 395 and the key 3| 5 engages the slot 398, after which the lever 3| 1 is pulled toward the operator to start a rapid forward movement of the grinding wheel 69 and the wheel slide 62. The rapid approaching movement of the wheel slide 62 continues until the dog I42 engages and actuates the limit switch I3I to break the circuit and deenergize the solenoid I98 to release the tension of the spring I and shift the clutch member I9I toward the right (Fig. 7,) into a slow speed position. During the rapid approaching movement of the grinding wheel, a manually operable hand wheel 369 may be rotated to operate a spark splitting device, that is to shift the grinding wheel spindle 6| axially in either direction precisely to locate the grinding wheel 69 relative to the crankpin to be ground, so that when the rapid approach is reduced to a slow approaching feed of the grinding wheel, the side grinding of the wheel on the cheeks of a crankpin will be equalized. The power approaching feed of the wheel at a slow rate continues until the dog I36 actuates the limit switch I33 to open .a circuit, thereby releasing one side of the magnetic switch 39I to stop the rotation of the wheel feed motor 89. The body of the crankpin may then be ground to the desired extent by manual rotation of the feed wheel 18. During the initial grinding of a crankpin 295, the work steadying shoes 2I9' and 2I I remain out of contact with the pin to al- "low the grinding wheel 69 to rough grind and round up the pin. After a preliminary grinding on the pin, the operator moves the steadyrest shoes 2| 9 and 2 into an operating position (Fig. 15) and thereafter manually adjusts the shoes'2I9 and 2 by actuating the knobs M8 and 226, respectively, during the grinding operation as the pin is ground to size.

After the pin has reached the desired size, the

lever 259 being in a downward position, the lever 3| I moves away from the operator, which serves to start the rotation of the motor 89 in the Igverse direction and, through the electrical switches and circuits above described, serves to cause a rapid rearward-movement of the-wheel slide 62 to remove the grinding wheel 69 to its rearward or inoperative position. The lever 23I of the steadyrest is then raised to withdraw the locating plunger 239, and the steadyrest slide 298 is withdrawn by actuating the lever 238, after which the control lever 259 is allowed to move 5 upwardly to withdraw the pin 316 from the hole 301 so that the lever 258 may be again shifted through position 2501: into position Gb or 2500 to traverse the work supporting table 2! longitudinally to position the next crankpin in operative position opposite the operative face of the grinding wheel 60. The infeed and sizing of the pin are then controlled in the manner above described. After all of the pins which are inaxial alignment have been found, the push button 3" may then be pushed to operate through the control switches above described to stop the rotation of the work drive motor 35 with the work holders 28 and 29in an upright or vertical position, after which the clamping members 30 and 31 may be released and the crankshaft 205 indexed to bring the next set of crankpins into axial alignment with the work rotating and supporting spindles 26 and 21, after which the clamps 30 and 3| secure the crankshaft 205 in position and the cycle of operation is continued by traversing the table 2| and feeding the wheel 80 until all of the crankpins on the shaft have been ground to the required and predetermined size.

To facilitate accurate positioning of the table 2!, a jogging button 346 is provided which serves to jog or inch the motor i5! precisely to locate the table 2| relative to the grinding wheel 80. similarly ijogging button 349 is provided to permit jogg ng or inching the work rotating motor 35 in setting up the machine for grinding a particular crankpihfso that the operator may be sure that the table II is in a position so that the crank arms clear the side face of the grinding wheel 60 before the work 205 is set in continuous rotation for a grinding operation.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully-achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense;

We claim:--

1. A crankpin grinding machne'having a transversely movable wheel slide, a longitudinally traversable work table, each of which is operated by av separate reversible electric motor. a separate reversing switch operatively connected to control each of said motors, a single manually operable main control lever, and connections between said reversing switches and the main control lever whereby either the work table or the wheel slide motor is rendered inoperative during the operation of the other member.

2. In a grinding machine, a rotatable grinding wheel, a transversely movable slide therefor, means including a reversible motor to move said slide in either direction, a multi-speed gear mechanism including a clutch interposed between the motor andslide and arranged to move the slide at any one of said speeds, a solenoid to actuate said clutch, a-manually operable reversing switch to control said motor, and means including an electric switch actuated by movement of said slide to control said solenod andclutch to change the rate of movement of the slide.

3. In a grinding machine, a rotatable grinding wheel, a transversely movable slide therefor, means including a nut and screw mechanism to move said slide, means including a reversible electric motor to rotate said feed screw in either direction, a two-speed gear mechanism including a clutch interposed between the motor and feed screw and arranged to rotate the feed screw at either of said speeds, a solenoid to actuate said clutch, a manually operable reversing switch to control said motor, means including a limit switch to control said solenoid and clutch to change the rate of movement of the slide, and an adjustable cam on said slide to actuate said switch.

4. In a grinding machine, a rotatable grinding wheel, a transversely movable slide therefor, means including a rotatable screw and a nut to move said slide in either direction, a two-speed gear mechanism including a clutch to rotate said feed screw at either of two speeds, means including a reversible electric motor to transmit power to said gear mechanism, a manually operable reversing switch to control said motor, means normally to hold said clutch in a low speed position,

a solenoid to shift said clutch into a high speed position, and means including a limit switch and a dog to control said solenoid so that the grindingwheel may be caused to move rapidly in one direction until the slide has reached a predetermined point and to move thereafter at a slower rate.

5. In a, grinding machine, a rotatable grinding wheel, a transversely movable slide therefor, a rotatable work support, a longitudinally movable table therefor, means including a rack and gear to traverse said table, means including a reversible electric motor to rotate said gear in either direction, a two-speed gear mechanism including a clutch interposed between the motor and rack and gear which is arranged to rotate said gear and traverse said rack and table at either of two speeds, a reversing switch to control said motor, and a manually operable control lever which is operatively connected to actuate said clutch when moved in one direction and to actuate said reversing switch when moved in another'direction.

6. In a grinding machine, a rotatable grinding wheel, a transversely movable slide therefor, a two-speed gear mechanism including a clutch to move said slide transversely in either direction, means to move and normally to hold said clutch in a slow speed position, a solenoid to move said clutch into a high speed position, a reversible electric motor to drive said gear mechanism, a magnetic reverse starter switch therefor, a manually operable reversing switch, and -a normally closed limit switch which is opened after a predetermined fast approaching movement of the slide to actuate said solenoid and thereby reduce the rapid approaching feed to a slow feed.

7. In a grinding machine having a rotatable grinding wheel, a transversely movable slide therefor, a two-speed gear mechanism including a clutch to traverse said slide in either direction, a revers'ble electric motor to drive said gear mechanism, a reversing switch therefor, means to move and normally to hold said clutch in a slow speed position, and a solenoid to move said clutch to a high-speed position, and a pair of spaced limit switches which are connected in series with said magnetic reverse starter switch to stop the wheel slide motor and prevent overrun on the forward and rearwardmovement of the slide.

8. In a grinding machine, a rotatable grinding wheel, a transversely movable slide therefor, means including a rotatable screw and a nut to move said slide in either direction, a two-speed ing a reversible electric motor to actuate said gear mechanism, means normally to hold said clutch in a low speed position, a solenoid to shift said clutch into a high speed position, a manually operable reversing switch to start said motor in either direction, a limit switch and an adjustable cam for actuating said limit switch which are interposed between the base and slide, said limit switch being arranged to operate a circuit after the wheel has moved rapidly toward a work piece to actuate said solenoid and shift the clutch into a slow speed position to cause a slow movement of said wheel and slide.

9. In a grinding machine having a base, a ro tatable grinding wheel, a transversely movable slide to support said wheel, means including a reversible electric motor which is operatively connected to move said slide in either direction to position the grinding wheel adjacent to the work piece or to move the same to an inoperative or rearward position, an intermediate slide supporting said reversible motor, a manually operable nut and screw mechanism interposed between the intermediate slide and base whereby the grinding wheel may be 'manually fed into the work, a reversing switch to control said motor, a longitudinally movable work supporting table, means including a manually operable lever to control the direction of movement of the table, and connections between said lever and said reversing switch whereby movement of the control lever in one direction serves to actuate the reversing switch and thereby control the transverse move- .ment of said grinding wheel slide.

10. In a grinding machine having a rotatable grinding wheel, a transversely movable slide therefor, means including a reversible electric motor to feed said slide, a longitudinally movable work supporting table, a two-speed gear mechanism including a clutch to traverse said table, a reversible electric motor to drive said gear mechanism, a magnetic reverse starter switch therefor, a reversing switch for controlling the. reverse starter switch and motor, a limit switch, means to actuate said limit switch by and in timed relation with the forward movement of said wheel slide normally to render said table traversing motor inoperative during the infeeding movement of the grinding wheel, and a second limit switch connected in parallel with the first limit switch which is actuated by and in timed relation with the movement of said clutch to a slow speed position to close a circuit to permit the wheel slide to remain in a forward position during a slow truing speed of the work table.

11. In a grinding machine having a longitudinally movable work supporting table, means including a reversible electric motor to traverse said table in either direction, a reversing switch therefor, a rotatable grinding wheel, a transversely movable slide therefor, means including. a. reversible electric motor to traverse said wheel slide in either direction, a reversing switch therefor, and a limit switch actuated by the forward movement of said slide to break a,circuit and render the table traverse motor inoperative during the infeeding movement of the wheel slide.

12. In a grinding machine having a longitudinally movable work supporting table, a reversible motor to traverse said table in either direction, a reversing switch therefor, a rotatable work support on said table, an electric motor to rotate said work support, a rotatable grinding wheel, a transversely movable slide therefor, means including a reversible electric motor to traverse said slide in either direction, a reversing switch therefor, a steadyrest which is movable to and from anoperating position, and a limit switch which is operated when the steadyrest is moved to an inoperative position to break a circuit and prevent rotation of the work drive motor.

13. In a grinding machine having a longitudinally movable work supporting table, a reversible motor to traverse said table in either direction, a reversing switch therefor, a rotatable work support on said table, an electric motor to rotate said work support, a rotatable grinding wheel, a transversely movable slide therefor, means including a reversible electric motor to traverse said slide in either direction, a reversing switch therefor, a steadyrest which is movable to and from an operating position, and a limit switch which is actuated by the steadyrest when the steadyrest is moved to an operative position to open a circuit so as to prevent rotation of the table drive motor when the steadyrest is in an operative position.

14. In a grinding machine, a rotatable grinding wheel, a transversely movable wheel slide to support said wheel, means including a reversible electric motor to move said slide in either direction, a longitudinally movable work supporting table, means including a gear mechanism and a clutch to move said table at either of two speeds, means including a reversible electric motor to rotate said clutch and gear mechanism, a reversing switch operatively connected to reverse said motor and gearing, a manually operable control longitudinally in either direction, a reversing switch therefor, a two-speed gear mechanism including a clutch which is interposed between the table and said motor, a single control lever which is arranged for movement in two directions,

connections between said lever and clutch whereby movement of the lever in one direction serves to actuate said clutch, and connections between said lever and the reversing switch to control the direction of movement of said table.

16. In a grinding machine having a transversely 'movable rotatable grinding wheel and a slide therefor, means including a reversible electric motor to traverse saidslide transversely in either direction, a reversing switch therefor, a longitudinally movable work supporting table, means including a reversible electric motor .to traverse said table longitudinally in either direction, a reversing switch therefor, a control leve'r which is slidable vertically and pivotally mounted, connections between said lever and said second reversing switch whereby movement of the control lever about its pivot serves to control the direction of movement of said supporting table,

ment of said lever in one direction serves to actuate said clutch, connections between said lever and the second reversing switch whereby pivotal movement of said control lever in a second direction serves to control the direction of movement of said table, and connections between said lever and the first reversing switch which are rendered effective when said control lever is moved vertically to control the forward and rearward movement of said wheel slide.

JOHN I. GARSIDE. CARL G. FLYGARE.