US2127877A - Grinding machine - Google Patents

Description

Allg. 23, 1938; Q F, MIAGLOTT 2,127,877 @BINDING MACHINE Filed March 3. 1956 4 sheets-Sheet 1 I a," Witness. I

Aug. 23,. 1938. G. r. MAGLcfrT GRINDING MACHINE Filed'llarch 3, 1936 4 Sheets-Sheet 2 306 Inventor ff f MM Figa# Witness Cd/7&4 7015204@ 4 Sheets-Sheet 3 G. F. MAGLOTT GRINDING MACHINE Filed VMarch 3, 1936 Aug. 23, 193s.

171 Wbtness Va/Mu im Aug. 23, 1938. GL F. MAGLTT GRINDING MACHINE Filed March 3, 1936 4 Sheets-Sheet 4 W Inventor Patented Aug. 23, 1 938 GRINDING George'F. Maglott, Wrentham, Mm., assigner to Brown and Sharpe Manufacturing Company, a corporation of llitliode Island Application `March 3, 1936, SerlalNo. 66.803

Claims.

The present invention relates to grinding machines and is herein disclosed as embodied-in a hydraulically driven surface grinding machine having a rotary grinding wheel, a reciprocable 5 work table, and a cross slide on which one of said parts is carried. v

It is a primary object of the invention to provide in a machine of this description, a novel and improved hydraulic operating and control mechanism which is of simple construction and is well adapted to insure a maximum degree of versatility and accuracy in the operation of the niachine. v v

It is more specifically one object of the invention to provide a novel and improved hydraulic cross feed mechanism for the machine which is well adapted for intermittent operationV to im partv closely regulated increments of relative transverse movement to the grinding wheel and work in timed relation to the table reciprocation for the grinding of successive portions of a ilat work piece.

With these and other objects in view as may hereinafter appear, a principal feature of the invention consists in the provision of a metering valve arranged to supply measured amounts of liquid to the cross feed cylinder -and ram of the machine, for imparting accurately determined `increments of cross feeding movement in timed r'elation to the lengthwise reciprocation of the work with relation to the grinding wheel.

Anotherieature of the invention consists in the provision in the exhaust line from the cross feed cylinder and ram, of a check valve which is ar'- ranged to provide a relatively high back pressure against the operation of the metering valve, and so to insure the accurate operation of the hydraulic cross feed 'devices to produce the desired relative movement of the work and grinding wheel,` and to maintain these elements firmly in their adjusted position.

In accordance with another feature of the invention, a control mechanism is provided for the cross feed which comprises a cross yfeed reversing and shut-off or hand feed valve having alterna.-

tive operating positions in which' the cross feed will operate in opposite directions, and a third handposition in which the supply of liquid under pressure is shut off, and ahy-pass is provided directly from one end to the other of the cylinder to facilitate a manual operation ofthe cross feed.

Another feature of the invention consists in the provision of an interlock between the table throttle valve and the cross feed truing controls nr. for the machine which isrendered operative dur- (ci. :r1-zas) ingv table reciprocation or alternatively during wheel truing,- to lock the other of said controls out oi' operation. v Y

'I'he several features of the invention consist also in the devices, combinations and arrangement of parts hereinafter described, which together with the advantages to be obtained thereby, will be readiiyunderstood by one skilled in the art from the following description taken in connection with the` accompanying drawings, in which Fig. l is a view in right side elevation partly in section, of a surface grinding machine embodying in a preferred form the several features of the invention; Fig. 2 is an enlarged detail view in front elevation of the control panel of the machine as indicated by the line 2--2 of Fig. 1;`Fig.` 3 is a sectional view taken on the line 3-3 of Fig. 2; Fig.4' is an enlarged plan view partly in section, of the several control valves taken substantially on the line 4--4 of Fig. 2; Fig. 5 is a detail sectional view of theiruing valve taken on the line 5 5 of Fig. 2; Fig. 6 is. a detail front view partly in section,'oi' the table and saddle; Fig. '7 is an enlarged detail sectional viewof thesaddle dog controlmechanism as shown in Fig. 6; Fig. 8 is an enlarged detail sectional view of the manual cross feed mechanism as shown in Fig. 6; Fig. 9 is an enlarged sectional detail view of the right hand end of the table cylinder as shown in Fig. 6; Fig. l0 is a plan sectional view taken on the line i-l of Fig. 2; Fig. il is a detail sectional view taken on the line iI-II of Fig. 10; Fig. l2 is a sectional view taken on the line I2--l2 of Fig. 2; and Fig. 13 is a diagrammatic view of the hydraulic operating connections for the machine.

The machine illustrated in the drawings comprises a base 20, a vertically adjustable column 22 on which is carried a grinding wheel 24 and a rotary spindle 2B, a reciprocable work table 2li, and a transversely movable saddle support 30 for the table.

The grinding wheel spindle 2l asbest shown in Fig. l, is preferably driven from an electric motor 22 mounted in the lower partof the column 22 through connections which include a pulley 34 on the spindle 26, a pulley 3B on the armature'shaft of the motor 32, and a belt Il as shown1 in dotted lines Fig. 1. Vertical adjustment of the column 22 is eil'ected through connections generally indicated in dotted lines in Fig. 1, which include a cooperating screw 40 and nut 42 supported respectively on the column 22 and base 20, a hand wheel 44, shaft 4G, a bevel gear, and a ring gear 50 secured respectively tothe shaft 46 and to the upper end of the screw 40.

'I'he table 20 of the present machine is mounted to slide on ways 52 and 50 (see Figs. 1 and 6) formed on the saddle l and is driven through hydraulicallyv operated connections which include a cylinder 55 rigidly secured to the saddle 20, and a piston 55 which is connected to move with the table 20 by means of a piston rod 55 passing through a packing box l in the cylinder, and secured at its outer end to a bracket 50 on the under side of the table.

The saddle 30 is mounted for movement transversely of the direction of table movement on two V-shaped ways l2 and 50 on the base 20, and is arranged for manual operation by means of a hand wheel 0I and screw 00 supported on the saddle l0 for engagement with a split nut 10 carried on the base 20, as hereinafter more fully described, or for power operation by hydraulically operated connections including a cylinder 12 (Figs. 1 and 13) securedto the under side of the saddle 00 and a piston 1| which is supported in a stationary position by means of a piston rod passing through a packing box 15 in the cylinder and secured at its outer end to a lug 10 on the base 20.

Oil under pressure is supplied to the cylinder 55 to control the direction and rate of travel of the table through connections which include a table throttle valve 00 and a table reversing valve 02 comprising a valve casing and an axially movable valve member 55. In order to insure an accurate and positive operation of the table reversing mechanism, there is also provided with the present construction, a table reversing pilot valve 04 which may be actuated either manually or automatically by means of table dogs,l and operates hydraulically to shift the table reversing valve member 05 as hereinafter more fully to be described.

Oil under pressure is.drawn from an oil reservoir 00 in the base of the machine (see Fig. 13) by means of an oil pump 00 which may be of any ordinary description, passing through a pipe 92 to the throttle valve 50. The throttle valve 50 preferably comprises a rotatable cylindrical member 04 having formed in the wall thereof an irregular slot or aperture 05 which may be moved into or out of register with an outlet pipe 05 to the reversing valve 22. The angular position of the throttle valve cylinder 00 is controlled to determine the rate of flow of liquid through the valve and the corresponding rate of table travel by means of a rotatable valve stem |00 secured to the member Il and provided at its forward end with a manually operable control knob |02.

Liquid under pressure passes from the throttle valve 00 through the pipe 05 into a chamber |00 formed by a reduced or spool portion of the reversing valve member 05, and thence through either of two pipes |05 and |00 depending upon the position of the reversing valve member 05 to one end or the other of the table driving cylinder 55 and piston 50. Liquid is allowed to pass from the exhaust end of the table cylinder 55 through the pipe |05, a chamber ||0 formed by a reduced or spool portion oi' the reversing valve member 00 and pipe ||2 forming the exhaust line to the reservoir 08, or alternatively through the pipe |00, a chamber ill in the reversing valve, an'd an extension of the exhaust pipe 2 to the reservoir.

In the preferred construction. illustrated, a shock absorber device is provided tocushion the stopping of the table, when the piston 55 is permitted to travel-to the extreme end ot the cylinthrough the port I I l to the pipe connection |05 in the form of a narrow slot which extends longitudinally to the extreme end of the cylinder. Similarly, there is provided at the right hand end of the cylinder 55, a port ||3 to the pipe connection |00 in the form of a narrow slot which extends longitudinally to the adjacent end of the cylinder. With this construction and arrangement of the ports |01, |09, ||I and H3, it will readily be seen that as the piston 56 approaches, for example, the left hand end of the cylinder 55, the port |01 will be shut oif allowing only a very restricted exhaust of the remaining oil in this end of the cylinder As the piston 55 continues its movement to the left, the port is gradually closed so that a continuously increasing back pressure to the continued movement of the piston 55 is built up to correspondingly check the speed of the table 20 and piston 50 which are thus brought gradually to a stop without shock or jar. In order to maintain the pressure in the system at a substantially constant predetermined level, there .is provided in the supply line 02 from the pump 90, a high pressure relief valve generally indicated at ||5 which for purposes of illustration may be assumed to have a setting of 100 lbs. per square inch. A similar relief valve generally indicated at ||5 is provided in the exhaust line ||2 which may be assumed to have a setting of 4 lbs. per square inch, so that a sufficient back pressure is maintained at all times to prevent ingress of air in the system.

In accordance with one feature of the invention, a master stop valve is provided for the machine which operates to connect the pressure line 92 directly to the exhaust line H2, so that all of the hydraulically controlled portions of the machine are rendered inoperative, and further operates to provide a by-pass from one end of the table cylinder 55 and ram 55 to the other independently of the position of the table reversing valve member 85. 'I'he master stop valve comprises a cylindrical valve member |20 having formed therein two transversely extending ducts |22 and |24 which for one angular position of the member |20 form connecting passageways respectively in the pipe lines |05 and |00 to the table cylinder 55. vThere is also formed in the valve member |20, a longitudinally extending duct |25 which is arranged for another or stop position of the valve member |20 to provide a direct connection between the lines |05 and |05 leading to the table cylinder 55, and'also for this position of the valve connects an extension |28 oi' the supply line 02 directly to an extension |30 of the exhaust line ||2. With the stop valve member |20 in the operating position shown in Fig. 13, the extensions 20 and |00 respectively of the supply and exhaust lines are shut oif, and liquid is permitted to flow freely between the reversing valve 02 and the table cylinder 55 through pipes |05, |00 and ducts |22 and |20.

When the stop valve member |20 is turned to stop l in stop position.

of a full supplyof oil in the system during manual operation.

The position of the master valve member |20 is controlled through connections which include,4

a pinion |34 (see Figs. 6, 7, 10 and 11) formed on one end of the valve member |20 which meshes with a rack |36 on an axially movable control rod |30. A'compression spring |40 coiled about the rod |36 between an abutting portion of the rack |36 and a stationary collar |42 secured by a screw |43 to thesaddle, tends normally to move the 'rod rearwardly to maintain the valve member In accordance with one feature of the invention, a latch mechanism for holding the control rod |36 in a forward or operating position is provided which may be tripped.

automatically through the operation of dogs on the saddle 30 or manually by a light pressure on the part of the operator to cause the control rod |38 and valve member |20 to move to stop position under the pressure of the spring |40. The latch comprises a laterally extending arm |44 secured to `a rock shaft |46 and varranged for engagement with a notch |46,'in the control rod |30 to maintain the valvein operating position. Also secured to the rock shaft |46 is an upwardly extending lever arm |50 which contacts with one end of a pin or plunger |52 supported in a bore casting directly abovethe saddle way 64. A com? pression spring |56 seated at' one end in a recess in the lever |50 and at its other end in a recess -in the saddle casting, tends to rock the lever'll, shaft |46 and latch- |4'4 in a direction to engage the latch in its notch |40 and to maintain the farm |50 and pin |52 -in a fully extended position. The latch |44 may be tripped automatically to stop the machine by the movement of the saddle 30 to -a predetermined position in either direction by means of dogs |58 adjustably mounted in a T-shaped slot |60 in the base 20, which are arranged to contact with and move the pin |02 and lever arm |50 to the right (see Figs. 6 and 7) against the pressure of the spring |56 to release the latch |44.

For manual operation of the control rod |30,

there is provided on theforward end thereof, a

cylindrical cap v|62 which is connected` for a limited axial movement on the shaft |30 by means of a pin |64 secured to the shaft and extending through a longitudinal slot |66 in thecap |62.v

As best shown in Fig. 11, one side ofthe cap |02 is cut away to form a4 cam surface |10 which is arranged when the cap |62 is pushed inwardlyl by the operator, to engage' against and tip the latch |44 to stop the machine.

^In order to' enable the'operator readily to move the control rod |36 and masterv valve member |20 to running position against the pressure of the spring |40, a manually operable lever |12 is pivotally supported on a rod |14 on the front of the machine, and is provided with a slotted portion |15 to receive a 'forward extension Aof the' cap |62 which is provided at its outer end with an enlarged head |16, so that a forward'movement of the hand lever |12 will operate to move thel coiled about the pivot rod |14 between the two arms of the forked hub of the lever |12, and con- I nected at one end to the lever, tends to maintain the hand lever |12 in a fully retracted inoperative position (see Figs. 2 and 10) Forthe manual operation of the table 20, a table hand wheel |1| is rigidly secured to the forward end of a shaft |13 (see Figs. 1. 10 and 13) which is supported for rotational and limited axial movements in bearings formed in the saddle 30. A pinion |11 secured to the rear end of the shaft |13 is arrangedfor a relatively advanced position of the shaft |13 and hand wheel |1| to mesh with a rack |19 secured to the table 20. A spring-pressed plunger. |6I supported in an adjacent portion of the saddle is arranged for engagement alternatively with one of two grooves `formed inthe shaft 13 to maintain the shaft |1| and pinion |11 alternatively in an advanced operative or retracted inoperative position.

` In accordance with the present invention, hy draulically operated connections are provided which are rendered operative upon movement of 'hand feed only when the master valve |20 is turned to stop position. The connections provided to this end, comprise a piston |63 secured to the hand wheel shaft |13 and arranged for axial movement in a' cylinder |85 through which the shaft |13 extends. Oil under pressure is supplied to the cylinder |85 by means of an ex- |54 which extends laterally through the sadsdlev on the part of the operatorybeing' maintained in this p osition by the action of the spring plunger |0| in its cooperating groove as above described. The table reversing pilot valve 8 4 through which 06 is Vpreferably controlled, comprises an axially movable valve member |60 which is controlled v through mechanical connections including a control lever which may be operated either manually or automatically by engagement with dogs adjustably supported on the table. The pilot valve member |80 -is connected by means of a rod |02 i to alever arm |84 on a vertically extending post |01 on the saddle 30 which has secured at its upper end an actuating lever |60. The lever |00 is formed for convenient manipulation by the operator, and is further provided with a rearwardv extension for engagement with table dogs the operation of the table reversing valve member |90 adjustably supported in a T-shaped slot |92 formed in the table.

The operation of the pilot valve to control the position of the table reversing valve member 06 will be readily understood from an inspection of the partly diagrammatic Fig. 13 of the drawings. Liquid under 'pressure passes from the supply line 92 -through a pipe connection |94, and Va throttle valve |96 which may be of ordinary construction, to'a chamber |98 formed by a spool portion of the pilot valve member |60, and thence through pipe connection 200 or 202 to one end or the other of the, reversing valve 02 depending upon the position of the pilot valve member |80. Simultaneously liquid is exhausted from the opposite end of the reversing valve 82 through the other of said connections 200 and 202 through one of two chambers 204 and 206 formed by spool portions of the pilot valve member |80 and exhaust connections therefrom hereinafter more fully to be described. With the construction and mode of operation of the table reversing valve 82 and pilot valve 84 associated therewith as above described, in which the position of the table reversing valve member 86 is shifted through the operation of hydraulically operating means, it will readily be seen that a certain and accurate operation of the table reversing mechanism is secured to insure a uniform operation of the reversing valve and to avoid any possibility of stalling the table upon reversal.

In accordance with the present invention, a novel and improved hydraulic mechanism is provided for imparting cross feeding movements to the saddle in timed relation to the longitudinal reciprocatory movements of the table which comprises a metering valve generally indicated at 2I0 adapted for supplying measured amounts ofu liquid under pressure to one end or the other of the cross feed cylinder 12 and ram 14 to advance the saddle by steps of predetermined length. 'I'he metering valve 2I0 comprises a cylindrical casing within which a piston 2|2 is free to move back and forth, the length of movement being regulated by means of an adjusting screw 2|4 threaded into one end of the cylinder 2 I0 to serve as a stop for the piston 2|2 and provided at its outer end with a knurled head 216 for adjustment by the operator. In the operation of the device, liquid under pressure is admitted into one end of the metering valve 2I0 driving the piston to the opposite end of the cylinder and forcing the liquid contained therein through connections hereinafter described, into one end or the other of the cross feed cylinder 12 to cause a relative displacement of the ram 14 in the cross feed cylinder 12 which will correspond exactly to the volume of liquid expelled from the metering valve 2| 0.

Further in accordance with the present lnvention, the operation of the metering valve 2I0 is controlled by means of a cross feed control valve 220 having a movable valve member 222 which is in turn controlled by the operation of the reversing valve member 86 above described, to cause the intermittent cross feeding movements to take place automatically at the end of the table movement in each direction. The cross feed control valve member 222 has formed thereon two reduced or spool portions to form chambers 224 and 226 within the valve and in the ends thereof cylindrical bores 228 and 230 which are arranged to llt over cylindrical plugs 232 and 234 respectively, formed, in opposite ends of the valve cylinder 220.

The control valve member 222 is shifted in one direction or the other between two extreme positions at opposite ends of the valve cylinder 220 at each reversal in the position of the pilot valve member |80 and table reversing valve member 86 to reverse the direction of table travel by means of the exhaust pressure set-up in one oi the pipe connections 208 or 202, by the movement of the reversing valve member 86 from one to the other of its alternative operating positions. This exhaust pressure passes from the connection 200 and chamber 204 in the pilot valve 84 through a connection 236 including an axial bore'in the plug 232 to the left hand end of the control valve (see Fig. 13), or alternatively from connection 202 and chamber 286 in the pilot valve 84 through'a connection 238 including an axial bore in the plug 234 to the right hand end of the control valve 220. In order to take care of excess liquid exhausted from the ends of the reversing valve 82, through connections 200 or 202 to the control valve 220 as above described, two extensions 240 and 242 of the exhaust line ||2 are connected to each end of the control cylinder 220 so that as the valve member 222 moves to its extreme position in which the plug 232 or 234 is disengaged from the corresponding bore in the control valve member 222, additional liquid exhausted from the reversing valve as above described, is permitted to flow freely past the plug 232 or 234 as the case may be, to the corresponding extension 240 or 242 of the exhaust line I|2. Liquid is exhausted from the leading end of the control cylinder 220 as the valve member 222 is moved from one extreme position .to the other through the connection 236,

chamber 204 in the pilot valve 84 and an exhaust connection 244 therefrom,4 or alternatively through the connection 238, chamber 206 in the pilot valve 84 and an exhaust connection 246.

The operation of the control valve 220 and metering valve 2I0 to impart a step-by-step feeding movement to the saddle 30 may be described as follows: Assuming that the control valve member 222 has been moved to the right to the position shown in Fig. 13, liquid under pressure passes through an extension 250 of the supply line 82 and a throttle valve 252 which may be of ordinary construction, into the chamber 224 of the control valve 220, and thence through a connection 254 to the left hand end of the metering valve-2I0, causing the piston 2|2 to be forced to its extreme position to the right as shown in Fig. 13. The liquid thus expelled from the right hand end of the metering valve 2I0 passes through a connection 256 into the chamber 226 in the control valve 220, and thence through an outlet 258 to a cross feed reversing and shut-oil valve 260 from which the liquid passes through one of two connecting pipes 262 and 264 to the left hand or right hand end of the cross feed cylinder 12 depending upon the setting of the valve 260 to impart the desired increment of movement to the saddle 30.

Upon movement of the control valve member 222 to the left from the position shown in Fig. 13 upon the next reversal in the position of the table reversing valve member 86, the connection 258 is shut off, and the throttle valve 252 is connected to the chamber 226 and connection 256, thus causingliquid under pressure to be forced into the right hand end of the metering valve 2I0 to move the metering valve member 2I2 to the left. At the same time the connection 254 to the left hand end of the metering valve 2I0 is shut off from thesupply line including the throttle valve 252, and is then connected through the chamber' 224 and a connecting pipe 266 to the cross feed reversing and shut-off valve 260 so that the liquid forced out of the left hand end of the meter-r ing valve will pass through these connections to impart an additional increment of movement to the saddle 30 measured by the ,volume of liquid in the metering valve.

The cross feed reversing and shut-off valve 260 as best shown in Figs. l2 and 13, comprises a casing through which extends a tapered rotatable valve member 268 having cut in opposite sides thereof two ducts 216 and 212. The valve meml ber 266 may be turned to any one of three positions including an in feed position shown in full lines in the diagrammatic Fig. 13, which illustrates a sectional view of the valve looking from the rear. the shut-olf, or hand feed position indicated at 214 in dotted lines, and an out feed position similarly indicated at 216. In the full line position of the valve member 266 illustrated, liquid flows-from the meteringvalve 216 as above described, through the port 216 and connection 262 to the rearward or-left hand end of the cross feed cylinder 12 as viewed in Fig; 13.

Liquid is at the same time exhausted from the forward or right hand end of the cylinder 12 j through the connection 264, port 212 and an exhaust connection 216 to a check valve 266 which is connected to the exhaust line |12. When'the vcross feed reversing and shut-olf valve 'member is turned in a clockwise direction as viewed in Fig. 13, to the feed-out position indicated at 216, liquid flows from the metering valve 216 through the port 216 and connection 264 to the right hand or forward end of the cross feed cylinder 12,

while liquid is simultaneously exhausted from the other end through connection 262, port 212, exhaust connection 216, and check valve 266 to the exhaust line 112 as above set forth.

The valve member 266 also has an ,intermediate or shut-off position designated on 4the control panel of the machine as a hand feed position in which the valve member takes the dotted line position indicated at 214 in Fig. 13, so that the metering valve connections are entirely shut off. The connections 262 and 264 and alsothe v exhaust line 216 are connected through the port 212 permitting liquid to flow freely from one end to the other of the cross feed cylinder 12 for manual operation of the cross feed. A full supply of liquid is maintained at all times in the cross feed cylinder during manual operation of the cross feed by means of a check valve 262 which is connected in parallel with the cross feed relief valve 266 in the exhaust line 216, and operates to permit liquid to be drawn from the exhaust line i12 into the cross feed cylinder as needed.

In order to prevent possible overtravel of the saddle 66 and also to maintain the saddle firmly in each successive position to which it is shifted Ibythe operation of the metering valve 216 above described, the check ,valve 266 in the exhaust line`v 216 is spring-loaded by means of a compression spring 264 to provide a relatively high back pressure which is preferably set at lbs. per square inch.A Withthis construction and arrangement of the exhaust connections from the cross feed cylinder 12, it will be readily seen 'that a. relatively high back pressure will be applied against movement of the s addle during hydraulic operation in either direction without in any way interfering with the transfer of liquid from one end of the cylinder tothe other for the hand position of the cross feed reversing valve member 266 for manual operation of the cross feed.

In accordance with another feature of the present invention, a control means i's'provided in the. hydraulic connections 'including the metering 'i valve 216 and the cross feed cylinder 12 which may be adjusted to cause an increment of feeding movement to be imparted to the saddle 66 asl above described, at each end of the table recipro- .cation, or at one end or the other only, or to render said connections wholly inoperative ton Il actuate the cross feed.v To this end a control l provided in the pipe connection 266 through which liquid passes from the left hand end of the metering valve 216 (see Fig. 13) to the cross feed cylinder 12, and a similar control valve comprising a rotatable valve member 262 is provided in the pipe connection -266 through which liquid passes from' the right hand end of the metering valve. An L-shaped duct 264 in the valve member 266 is arranged for one position of the valve to provide a free passage through the pipe connection 266 to the cross feed cylinder, and for another position of the valve to shut oi! the connection 266, bypassing the liquid from the metering valve 216 through an exhaust connection 266 to the exhaust line |12. An L-shaped duct 266 in the valve member 262 is similarly arranged for one position of the valve member 262 to provide a connecting l passageway in the pipe connection 266 to the cross feed cylinder 12, and for another position of the valve to shut off the connection 256, by-passing the liquid forced from the right hand end of the metering valve 216 as shown'in Fig. 13 through an exhaust connection 666 to the exhaust line 112.

For convenience of operation, each of the valvev I members 266 and 262 preferably have stem por-l tions which extend upwardly through the saddle casing, and are provided at their upper ends with' manually operable lever arms indicated at 662 and 664 as shown in Figs. 1 and 3 respectively.

With the preferred construction shown, the

angular position of the cross feedreversing and shut-off valve `member 266 is" controlled by means of a hand lever 666 which is rigidly secured to a stem portion of the valve member 266 on the control panel formed on the forward end of the' saddle 66. A spring-pressed detent 666 formed in the hub of the handle 666 is arranged for engagement in any one of three recesses corresponding to the in," hand and out" positions of the hand lever andl valve to maintain these parts in adjusted position.

. In accordance with one feature of the present invention, an interlock is provided between the cross feed reversing and hand feed vcontrol lever` 666, and the hand feed connections comprising` the feed screw 68 and split nut 16 above referred to, which operates when the hand lever 666 is in its intermediate or hand position corresponding to the shut-off position of the valve member 266 to engage the nut 16 with the screw 66, and upon movement of the hand lever 666 to either its in" or out" positions, to disengage the nut from the screw, and thus to render the cross feed hand wheel 66 inoperative. As best shown in Figs. 8

316 which is provided at its lower end with a ingly into engagement with the screw 66. The

position of the nut 16 is controlled from the cross feed control lever 666 by means of a rearwardlyA extending control rod 622 which is connected at its forward end to turn withlthe valve member 266 and lever 666, and is provided along one side with a flattened portion 624. A block 626 carried 76' lon a pin 626 offset from the hub portion of the lever arm 616,.is arranged for engagement with the control rod 622, and serves to limit the movet ment of the lever 616 and nut' 16 toward the screw 66 under the pressure of the spring 616. with 55 and 12, the split nut 16 is carried on a lever arm g.

the hand lever 306, valve member 263 and control rod 322 in the hand position illustrated in Figs. 8 and 12, the block 323 engages against the fiattened portion 324 of the control rod 322, so that the nut 10 is permitted to engage with the screw 60. Movement of the hand lever 300 and control rod 322 in either direction to feed position, causes the block 326 to ride onto the round portion of the rod 322, to move the lever arm 3|! and nut 'Il out of engagement with the screw 60 against the pressure of the spring 3|..

In accordance with another feature of the present invention, there is provided with the present construction, a truing control valve 330 (see Figs. 2, 5 and 13) which is arranged to provide a steady flow of liquid under pressure through the reversing valve 260 to the cross feed cylinder 'I2 to provide a continuous cross feed of the saddle at a. predetermined rate for the operation of truing the grinding wheel. As best shown in Figs. 5 and i3 of the drawings, the truing valve 330 comprises a rotatable valve member332 mounted in an extension 334 of the pressure supply line 92, which is connected to the pipe connection 258. There is provided in the truing valve member 332, a duct 336 having a restricted portion 338 through which liquid under pressure is permitted to pass at a relatively slow rate for the operative or truing position of the valve, to the cross feed reversing valve 260 and cross feed cylinder 12. The position of the truing valve member 332 is controlled by means of a hand lever 340 which is mounted on a stem portion 342 of the truing valve member 332 extending through the control panel ofthe machine. l

With the preferred construction illustrated, an interlocking connection is provided between .the truing control lever 348 and the control knob |02 for the table throttle valve which is arranged to prevent the movement of the control lever 340 to truing position while the table throttle valve is open, and also operates to prevent the opening of the table throttle valve after the truing valve control lever 340 has been moved to truing position. As best shown in Fig. 2.0i the drawings, there is provided on the hub of the truing control lever 340, a segmental disk 344 which is arranged for the closed position of the table throttle valve 80 and control knob |02, to mesh with a corresponding cutaway portion 343 in a disk 340 secured to the stem |00 of the table throttle valve member 04. It will readily be seen from an inspection of Fig. 2, that the movement of the truing control lever 340 to the right to truing position, will engage the segmental disk 344 with the cutaway portion 340 of the disk 340 to lock the table throttle valve in off position illustrated in Fig. 2, and similarly a rotational movement of the table throttle control knob |02 will operate to move the cutaway portion 340 out of alignment with the segmental disk 344 to lo'ck the truing control lever 340 in its neutral or inoperative position shown in Fig. 2.

It will be understood that the invention is not limited to the specific embodiment shown, and that various deviations maybe made therefrom without departing from the spirit and scope of the Vappended claims.

What is claimed is:-

1. A grinding machine having in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a traversable slide on which one of said elements is carried, a hydraulic system for the machine including a cylinder and piston operatively connected to reciprocate the table. a reversing valve operatively connected to reverse the direction of movement of the table, a fluid motor operatively connected to traverse the slide, a metering valve operatively connected to admit measured amounts of iluid underl pressure tothe slide fluid motor to move the slide a predetermined distance, and iluid pressure connections actuated directly by movement of the reversing valve for actuating the metering valve to impart an increment of movement to the slide.

2. A grinding machine comprising with a base, a rotary grinding wheel spindle, a, longitudinally reciprocable work table, a transversely movable slide support for one of said elements, a fluid pressure system including a piston and cylinder operatively connected to reciprocate said table, a reversing valve to change the direction of movement of 'said table, means including a piston and cylinder operatively connected to traverse said slide, a metering valve operatively connected to force a measured quantity of fluid to said second cylinder and cause a predetermined traversing movement of the slide, a pilot valve, and fluid pressure and exhaust connections therefrom for operating the table reversing valve, said connections being constructed and arranged for directing the exhausting fluid to actuate the metering valve.

3. A grinding machine comprising with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a transversely movable slide support -for one of said elements, a fluid pressure system including a piston and cylinder operatively connected to reciprocate said table, a reversing valve arranged to change the direction of movement of said table, a fluid motor connected to traverse said slide, a. metering valve comprising a cylinder, azpiston freely movable therein, a slide control valve having connections to opposite ends of said metering valve operable to discharge a predetermined volume of fluid a1- ternatively from opposite ends of said metering valve to drive the motor, and a pilot valve having pressure and exhaust connections therefrom for operating the table reversing valve, said connections being constructed and arranged for directing the exhausting fluid to actuate the slide control valve- 4. A grinding machine comprising with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a transversely movable slide support for one of said elements, a fluid pressure system including a piston and a cylinder operatively connected to traverse said slide, a metering valve in said system which is operatively connected to force a measured amount of fluid to said cylinder to move the slide through a predetermined distance, and a cross feed control valve including a control element having alternative feed positions to determine the directionof said movements imparted to the slide, and a third hand feed position in which liquid is permitted to circulate freely to and from both ends of the cylinder, mechanical hand feed connections for said slide, and an interlocking device rendered operative by movement of said control element to a feed position to positively disengage said connections.

5. A grinding machine comprising with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a transversely movable slide support for one of said elements. a fluid pressure system including a piston and a cylin-u 2,127,877 'der operatively connected'to traverse said slide,

a metering valve in said system which is operatively connected to force a measured amount of fluid to said cylinder to move the slide through a predetermined distance, anda cross feed control valve having alternative feed positions td determine the direction of said movements imparted to the slide, a third hand feed position in which liquid isby-passed freely from one endv tive feed positions to admit uid under pressure to one end or the other of said cylinder, anda hand 'feedposition in which liquid is by-passed freely from one end of saidcylinder to the other, hand feed connections for said slide including a screw and a cooperating split nut, and a connection lfrom said control valve rendered operative by movement of said control valve to either of said feed positions to disengage the nut from the screw.

'1. A grinding machine comprising with -a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a transversely movable',

slide support -for one of said elements, a uid feed control valve having alternative Vfeed positions to admit fluid under pressure to one end or the other of said cylinder, and a hand feed position in which liquid is by-passed freely from one end of said cylinder to the other, hand feed connections for saidfslide including a screw von the slide, a split nut on the base, spring means tending to move the nut-into engagement with the screw, and a cam operatively connected to said control valve, actuated by movement of said control valve to either of said positions to disengage the nut from the screw.

8. A grinding machine having in combination with a base, a rotary grindinglwheel, a reciprocaf ble work table, a fluid pressure system including a cylinder and a piston operatively connected to move the table, a reversing valve to change the direction of mo'vement imparted to the table by said cylinder and piston, means for supplying fluid to said 'reversing valve and cylinder at a relatively high pressure, means for exhausting uid from` said cylinder and reversing lvalve against a relatively low pressure, a table stop valve connected between the reversing valve'and cylinder, and arranged for the stop position of said stop valve to connect both sides of said cylinder directly to the pressure-supply and exhaust means.,

9. A grinding machine havingv in combination with a base, a rotary grinding'wheel, 'a reciproca- -direction of movement imparted to the table byA said cylinder and piston, a conduit from each end of the cylinder to the reversing valve, means.

for supplying fluid to said reversing valve at a relatively high pressure, means for exhausting iluid from said reversing valve against a relatively low pressure, and a table stop valve arranged for one' position of said stop valve to provide a free e for liquid through said conduits: and for an alternative position of said stop valve to provide a by-pass between said conduits to both ends of the cylinder and to said pressure supply and exhaust means.

10. A grinding machine having, in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a traversable slide on which one of said elements is carried, a hydraulic system for the machine including a supply line through which liquid under pressure is supplied, a cooperating cylinder and piston for reciprocating the table, a table reversing valve, table hand feed connections including an element shiftable to disconnect the hand feed connections, a hydraulic pressure connection from said supply line acting on said element to disconnect the handfeed, a low pressure exhaust line for said system, a master stop valve in saidl system movable to connect said supply line directly to the exhaust line to exhaust the pressure throughout said system and thereby to render saidhydraulic connections inoperative to move the table and to maintain said element in` discong nected position.

11. A grinding machine havl Vin combination with a base, a rotary grindlngwhe'el spindle, av longitudinally reciprocable work table, a traversable slide on which one of said elements is i carried, a hydraulic system for the machine including a supply line through which liquid under pressure is supplied, a cooperating cylinder and piston for reciprocating the table, a table reversing valve, table hand feed connections including an element shiftable to disconnect the hand feed connections, a detent mechanism for .maintaining said element yieldingly in either-of V its alternate connected and disconnected positions, manually operable means for shifting said element, a hydraulic connection from the supply line acting to maintain said element in disconnected position, a low pressure exhaust line in said system, a master stop valve movable to connect both ends of the table cylinder both to pressure and exhaust and thereby to exhaust the pressure throughout said system- Y l2. A grinding machine having in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a traversable slide on which one of said elements is carried, a hydraulic system for the machine includto running position and another direction to trip said latch.

i3. A grinding machine having in combination u with a base, a'rotary grinding wheel spindle, a

longitudinally reciprocable work table, a traversmeans for supplying uid under pressure to said reversing valve and cylinder, a stop valve shiftable to render said iluid under pressure inoperative to move the table, a control member movable to shift said stop valve, spring means acting on said member to shift said stop valve to stop position, a latch to maintain said. member and valve controlled thereby in runningposition, and a manually operable member to trip said latch.

14. A grinding machine having in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a traversable slide on which one of said elements is carried, a hydraulic system for the machine including a cooperating cylinder and piston forreciprocating the table, a table reversing valve, means for supplying fluid under pressure to said reversing valve and cylinder, a stop valve shiftable to render said fluid under pressure inoperative to move the table, a control member movable to shift said stop valve, spring means acting on said member to shift the stop valve to stop position, a latch to maintain said member and valve controlled thereby in running position, and connections actuated by movement of the slide to trip said latch.

l5. A grinding machine having in combination with a base, a rotary grinding wheel spindle. a longitudinally reciprocable work table, a traversable slide on which one of said elements is carried, a hydraulic system for the machine including a cooperating cylinder and piston for reciprocating the table, a table reversing valve, means for supplying fluid under pressure to said reversing valve and cylinder, a stop valve shiftable to render said fluid under pressure inoperative to move the table,v a control member movable to shift said stop valve, spring means acting on said member to shift the stop valve to stop position, a latch to maintain said member and valve controlled thereby in running position, a manually operable member to trip said latch, and connections actuated by movement of the slide to trip said latch.

16. A grinding machine having in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a traversable slide on which one of said elements is carried, a hydraulic system for the machine in- -cluding a cooperating cylinder and piston for reciprocating the table, a table reversing valve, a second cylinder and piston for moving the slide, a, supply line through which iuid under pressure is supplied to said system, an exhaust line for said system, a master stop valve for the machine arranged when moved to stop position to connect the supply line directly to exhaust and thereby to render said hydraulic connections inoperative to move the table and slide, and connections actuated by movement of the slide to a predetermined position to move said master valve to stop position.

17. A grinding machine having in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable work table, a travers- 'able slide on which one of s aid elements is carried, a hydraulic system for the machine includl ing a cylinder and piston operatively connected to reciprocate the table, a reversing valve operatively connected to, reverse the direction of movement of the table, a second cylinder and piston operatively connected to traverse said slide, a slide reversing valve, a metering valve comprising a cylinder and piston freely movabletherein. and having connections from each end thereof to said slide reversing valve, a slide control valve rendered operative upon reversal of the table in one direction to discharge a predetermined volume of iluid from said metering valve through one of said connections, and upon reversal of the table in the other direction to discharge a predetermined volume of fluid from the metering valve through the other of said connections.

18. A grinding machine having in combination with a base, a rotary grinding wheel spindle, a longitudinally reclprocable work table, a traversable slide on which one of said elements is carried', a hydraulic system for the machine including a cylinder and piston operatively connected to reciprocate the table, a reversing valve operatively connected to reverse the direction of movement of the table, a second cylinder and piston operatively connected to traverse said slide, a slide reversing valve, a metering valve comprising a cylinder and piston freely movable therein, and having connections from each end thereof to said slide reversing valve, a slide control valve rendered operative upon reversal of the table in one direction to discharge a predetermined volume of fluid from said metering valve through one of said connections, and upon reversal of the table in the other direction to discharge a predetermined volume of uid from the metering valve through the other of said connections, and a valve device adjustable to shut off either one or both of said connections from the reversing valve and slide cylinder.

19. A grinding machine having, in combination with a base, a rotary grinding wheel spindle, a longitudinally reciprocable table, a traversable slide on which one of said elements is carried, a fluidV motor and connections thereto including a `throttle valve having inoperative and adjustable running positions for driving the table, a second fluid motor and connections thereto for moving the slide, a truing control for admitting uid to move the slide at a truing rate Icomprising a valve having alternative truing and inoperative positions, and an interlocking device operable when one of said .valves is in running position to lock the other of said valves in inoperative position.

20. A grinding machine having, in combination with a base, a rotary grinding wheel spindle, a longitudinally reclprocable table, a traversable slide on which one of said elements is carried, a fluid motor and connections thereto including a throttle valve having inoperative and adjustable running positions for driving the table, a second iluid motor and connections thereto for moving the slide, a truing control for continuously admitting fluid to move the slide at a truing rate comprising a valve having alternative truing and inoperative positions, manually rotatable control elements associated with each oi' said valves, and an interlocking device comprising cam elements associated with each of said control elements constructed and arranged to lock either of said control members in inoperative position when the other of said control elements is in running position.

GEORGE F. MAGLDTI.

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