US2283792A - Grinding and lapping machine - Google Patents

Description

' May 19, 1942. R. A..co|

GRINDING AND LAPPING MACHINE Filed Aug. 24, 1940 2 Sheets-Sheet 1' 7 3mm FFH YNU/VD F7504 E y v R.- A. COLE 2,283,792

' GRINDING AND LAPPING MACHINE Filed Aug. 24, 1940 2 Sheets-Sheet 2 FFHYMCZND /7. E04 5 w 2 x mqm 1 Patented may re, race mania UNITED sTArEs rArEnr eerie;-

GRINDING AND EAPPlNG-MACmiiE Raymond A. Cole, Worcester, Mass... assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application August 24, 1940, Serial No. 354,124

8 Claims. (01. 51-3) 4 the invention is to provide a combined grinding first automatically ground for a predetermined time interval after which-the work piece is automatically lapped for a predetermined time interval. Another object of the invention is to provide a grinding and lapping machine in which the work piece is first ground to a predetermined extent after which a lapping mechanism is automatically moved into operative lapping engagement to perform a predetermined lapping operation. Other objects will bein part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features 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 claim.

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 a combined grind-= ing and lapping machine;

Fig. 2 is a combined cross-sectional view through the grinding machine showing the wheel the drawings comprising a base ill which sup- ,ports a transversely movable wheel slide H which is in turn mounted on transversely extending ways (not shown) on the base it. The wheel slide it supports a rotatable grinding wheel, l2, which is mounted on the end of a rotatable wheel and lapping machine in which the work piece is spindle l3. The wheel spindle i3 is rotatably journaled in bearings (not shown) in the wheel slide ii., The wheel spindle [3 may be driven by any of the well known mechanisms, such as an overhead belt drive, or an electric motor I t,

which is mounted on the upper surface of the wheel-slide ii. As illustrated in the drawings, a driving pulley i5 is mounted on the end of the motor shaft and is connected by a driving belt it with a pulley i'l mounted on the end of the wheel spindle iii. a

The base it also supports-a longitudinally movable table is which is arranged to recipro-=' cate longitudinally relative tothe base it on a fiat way it and a V-way 2d. The table i8 is provided with a rotatable work support includ= ing a headstock 2i and a, rootstock 22 each. cf which is provided with, av work supporting center 23 and 24 respectively rotatably to support a work piece 25 in operative relation with the grinding wheel it. The table it may be traversed longitudinally by a manually operable traverse mechanism which includes a rack bar it depending from the underside of the table it. The rack bar it meshes with a gear 2? mounted on the end of a rotatable shaft 2&. A manually operable traverse wheel 29 is mounted on the outer endof shaft 28 and is arranged to be manually rotated to traverse the table it longitudinally relative to the base it. If desired a power operated table traversing or reciprocating mechanism may be provided such as for example a mechanism of the type shown in the expired United States Patent Norton No. 762,838 dated June 14, 1904.

A wheel feeding mechanism is provided for manually feeding the grinding wheel toward and from the work,,which comprises a half nut 35 depending from'the wheel slide ii. The half nut 35 meshes with or engages a' rotatable cross feed screwtt. A forwardly. extending portion 3'! of the cross feed screw 36 is slidably keyed to .a rotatable sleeve 38. The rotatable sleeve 38 is formed as an integral part of a rotatable shaft which is mountedin bearings 39 and d!) in the base it. A manually operable feed wheel 3! is mounted on the outer end of a stud 42. The stud 62 carries a pinion 63 which meshes with a gear til mounted on the outer end of a sleeve shaft 38 so that a manual rotation of the feed wheel ii serves to rotate the feed screw 36 in either direction to cause a forward or rearward feeding movement of the grinding wheel i2 and the wheel slide Ii. The wheel feed dimay be provided with a micrometer adjusting mecha= screw 36 is rotatably supported in a. slidably keyed bearing 50 which is supported in a casing 5I on the base of the machine. A fluid pressure cylinder 49 is attached to the casing 5| and contains a slidably mounted piston 52 which is connected by a piston rod 53 with the bearing 50 and is arranged so that when fluid under pressure is admitted to a cylinder chamber 54, the piston 52 will be moved toward the right into its rearward position, as illustrated in the drawings, transmitting a corresponding movement through the feed screw 36, the half nut 35, to move the wheel slide II and the grinding wheel I2 rearwardly to an inoperative position. Similarly, when fluid under pressure is admitted to the cylinder chamber 55 or the cylinder chamber 54, a rapid approaching or receding movement of the grinding wheel I2 and wheel slide II is provided.

A fluid pressure system is provided to supply fluid under pressure for moving-the-piston 52 ported at the lower end of a rock arm 84. The rock arm 84 is pivotally supported by a stud 85 which is supported by a bracket 86 fastened to the base I0 of the machine. The upper end of the rock arm 84 is provided with a stud 81 which rides withinan annular groove formed in a spool-shaped member 88 supported on the lefthand end of the valve stem 65.

A suitable fluid pressure controlled or feed regulating mechanism is provided for modifying the rapid approaching movement caused by the piston 52 to obtain a controlled and predetermined infeeding movement of the grinding wheel I2. In the preferred construction a self-contained dash pot feed regulator is provided comprising a pair of dash pot cylinders 96 and 91 which contain dash pot pistons 98 and 99, respectively. The dash pot pistons 98 and 99 and their respective cylinders 96 and 91 are arranged with their axes parallel to each other and spaced on diametrically opposite sides of the piston rod 53. The dash pot pistons 98 and 99 are normally held in a rearward (right-hand) position bymeans of springs I00 and IN, respectively. An adjustable stop screw I02 serves to limit the rearward movement of the dash pot pistons 90 and 99, respectively. A slidable sleeve I03 is supported on the rear extension 53 of the piston rod 53. The sleeve I03 has a flanged portion I04 which is either formed integral therewith or fixedly secured thereto. The flange I04 is arranged to engage the right-hand end faces of the dash pot pistons 98 and 99, respectively.

so as to cause an infeeding or outfeeding movement of the grinding wheel I2. This system may comprise a reservoir 80 which is formed asa box-like section within the base I0 and serves to convey fluid through a pipe SI to a fluid pressure pump 02. The pump 62 forces fluid under pressure. through a pipe 83, to a control valve 94. The control valve 94 is preferably a piston type valve comprising a valve stem 65 having formed integrally therewith valve pistons 66, 61, 68 and 99. Fluid under pressure passing through the pipe 63 enters a valve chamber I0 located between the valve pistons 81 and 08 and passes through a passage 12, into the cylinder chamber 50, to move the piston 52 to its rearward position with the grinding wheel I2 separated from the work piece 25, as indicated in the drawings. During the rearward movement of the piston 52 toward the right, fluid is exhausted from the cylinder chamber 55, through a passage 76, into a valve chamber I'I, between the valve pistons 96 and B1, and out through a pipe 18 which exhausts into the reservoir 60. An adjustable relief valve II is operatively connected to the pipe 69 and serves to exhaust excess fluid under pressure directly to the reservoir 80 so as to maintain the desired operating pressure within the fluid pressure system.

. The "valve stem 55 is arranged so that it maybe moved endwise to shift the valve 64 into a reverse position so as to .cause either a forward or rearward feeding movement of the grinding wheel I2. In the preferred construction a spring 80 is provided to maintain the valve 54 normally in its right-hand end position to cause the piston 52 and the wheel slide II and grinding wheel I2 to remain in their rearmost position. A solenoid 8i mounted on the base I0 is provided to shift the valve 04 toward the left to cause a forward feeding movement of the grinding wheel I2 when desired. The solenoid BI is connected by a link 82 with a stud 93 sup- The stop screw I02 engages the flange I04 and thereby serves to limit the rearward movement of the dash pot pistons 98 and 99 toward the right.

The rapid forward feeding movement of the grinding wheel I2 and the wheel slide II continues until the adjustable nuts I05 on a threaded portion I06 of the extension 53a of the piston rod 53 engages the ,righthand end of the sleeve I 03. Continued movement of the piston rod 53a moves the sleeve I03 and the flange I04 toward the left and continued movement serves to move the dash pot pistons 98 and 99 in a direction toward the left. When the flange I04 engages the ends of the dash pot pistons 98 and 99, respectively, the rapid approaching or feeding movement of the grinding wheel I2 toward the work piece 25, as produced by the piston 52, is reduced to a slower predetermined grinding feed due to the fact that fluid conflned within the dash pot cylinders 96 and 91, respectively, which are interconnected, exhausts through a passage I01, a needle valve I08, through a pipe I09, into a reservoir iI0. By adjusting the aperture of the needle valve I08, a desired and predetermined infeeding movement of the grinding wheel I2 may be obtained.

When fluid under pressure is admitted to the cylinder chamber 54 to cause a rearward movement of the piston 52, thesleeve I03 together with the flange I04, is moved rearwardly by means of the released compression of the springs I 00 and IN which returns the dash pot pistons 98 and 99, respectively, to their rearward positions and moves the flange I04 and its supporting sleeve I03 toward the right until the flange I04 engages the adjustable stop screw I02. During the rearward movement of the dash pot pis tons 98 and 99, a suction is created within the dash pot cylinders 96 and 91, respectively, which serves to aid in drawing fluid from the reservoir H0, through a pipe I, and a ball check valve H2. to fill the dash pot cylinder chambers 96 and 9! for the next infeeding movement of the grinding wheel -I I2. iJuring the infeeding movement of the dash pot pistons 98 and 99, fluid withinthe dash pot cylinders 96 and 91 serves to hold the ball check valve II2 closed so that' fluid within the dash pot cylinders 96 and 91 is forced out through the passage I01 and the needle valve I08, into the reservoir IIO. to con- 1101 the rate of the infeeding movement, as desired. An adjustable throttle valve III is provided to facilitate the exhaust of fluid from the dash pot chambers 95 and 91 after the port or passage I! is closed by the piston 98. If desired, the throttle valve III may be used to give a very fine final feed just prior to the stop II3 engaging its stop surface II4. In the latter case two distinct feeds of the wheel could be obtained, one feed by manipulation of the valve I08 combined With the opening of the valve III which would continue until the passage I01 is cut off, after which the infeed would be reduced to a very slow infeed control by the throttle valve In.

The forward feeding movement of the grinding wheel I2, as controlled by the dash pot pistons 98 and 99, respectively, continues until an adjustable stop collar II3 carried by the sleeve I03 engages a fixed stop surface II4 on the rear face of the dash pot cylinder head. A pair of lock collars II5 serve to position the stop collar H3 and to lock the same in adjusted position.

A throttle valve H6 is located in the pipe line 18 and serves to control the exhaust of fluid from the cylinder 49 so as to regulate the speed of movement of the grinding wheel I2 and its supporting wheel slide II during the rapid approaching or positioning movement thereof.

In order to obtain one object of the inven- Lion it is desirable to provide a suitable control mechanism for the wheel feeding mechanism which is arranged so that when a work piece has been inserted in the machine, it is merely necessary for a control lever to be shifted to initiate an approaching movement of the grinding wheel which continues until the grinding wheel approaches the work piece, after which the approaching speed is reduced, to a predetermined grinding speed. The infeeding continues until 'the stop II3 engages the stop surface H4 and positively limits the infeeding movement of the grinding wheel I2. The grinding wheel I2 is then allowed to remain in grinding contact with the work piece for a definite predetermined time interval, after which the control valve I54 is reor feed control valve 64 so as to control the entire infe-eding movement of the grinding wheel I2, namely to control the over-all cycle including the rapid approaching movement of the grinding wheel I2, the slower grindinginfeed of the wheel; and the dwell which occurs thereafter before the grinding wheel is removed to its rearward or inoperative position. A pair of push button switflios I22 and I23 are mounted on the H6 located in the exhaust pipe line 78.

front wall of the machine base I0. The push buttons I22 and I23 are arranged to be actuated by a control lever I24 which is pivotally supported on a stud I25 which is fixedly sup ported on the base III of the machine. The button I22, when pushed, is arranged to cause a rearward feeding movement of the grinding wheel I2 and its supporting slide II and the push button I23,'when actuated serves to start thegrinding cycle.

The time .delay relay I20 is one of the standard electrically operated adjustable time delay relays such as that known as the Microfiex instantaneous reset timer manufactured by the Eagle Signal Corporation, Moline. Illinois. The Microfiex timer is a synchronous motor operated time delay relay and consists of a clutchoperating mechanism and a motor and gear train assembly. with an electromagn-etically operated clutch for coupling them together. It is entirely automatic in action and requires only the closing or opening of the timer control circuit to initiate a cycleof operation. In the normal position, no current is applied to the timer; all contacts are open. The cycle is initiated by momentarily-closing the switch I23 of the timer control circuit.- When the control circuit is closed the timing cycle starts. When the timing interval terminates, breaking the circuit serves to de-energize the solenoid 8| which releases the compression of the spring to reverse the control valve 64 and cause a rearwardgnovement of the wheel slide II and the grindingwheel I2. The timer automatically resets for the next grinding cycle. If for any reason it is desired to stop grinding during a grinding cycle, the lever I24 is moved in a clockwise direction (Fig. 1) instantaneously to open the push button switch I22 which opens a circuit to interrupt the time delay relay and cause the grinding wheel to move to a rearward position.

The time delay relay may be adjusted to control the entire approaching and'infeeding movement of the grinding wheel, that is, the rapid approach, grinding feed and dwell. The relay I20 allows a certain time interval to elapse after the push button I23 is actuated to initiate the forward movement of the grinding wheel I2 and to control the dwell thereafter so as to grind the work piece 25 to the desired and predetermined size. The time delay relay I 20 is so connected with the push buttons I22 and I23 and also with the solenoid 8I that when the lever I24 is rocked in a counterclockwise direction to start a grinding cycle, the push button switch I23 is actuatedto start the time delay relay I20 functioning and at the same time energizes the solenoid 8| which serves to shift the control valv toward the left against the compression of the spring 80 to admit fluid under pressure from the pipe. 63 through the passage I6, into the cylinder chamber 55, to cause the grinding wheel I2 and its supporting slide II rapidly to approach the work piece 2I at a rate governed by the throttle valve The rapid approaching movement of the grinding wheel I2 and its supporting slide II continues until the sleeve I03 and its flange I 04 engage the dash pot pistons 98 and 99, respectively, after which the rapid approaching movement caused by the fluid pressure operated piston 52 is slowed down to a-slow uniform grinding speed as ccntrolled by the exhaust of fluid from the dash pot cylinders 96 and 91, respectively, through a needle valve I08. into the reservoir III). The

I 54 to cause the slow grinding infeed continues until the adjustable stop II3 engages the stop surface II4 which positively limits the grinding infeed and allows the grinding wheel I2 to remain in grinding contact with the work piece 25 to finish grind the work.

After a predetermined time interval has elapsed according to the adjustment of the time delay relay I20, the solenoid 8| is automatically de-energized, thereby releasing the compressed spring 80 which returns the control valve 64 into the position illustrated in the drawings so that fluid under pressure passing through the pipe 63 passes through a passage 12 into the cylinder chamber wheel slide I I and grinding wheel I2 to move rapidly to their rearward or inoperative position.

The push button I22 is provided so that if for any reason it is desirable to interrupt the grinding cycle and cause the grinding wheel I2 to move rearwardly without completing its cycle, the lever I24 may at any time during the grinding cycle be moved in a clockwise direction to operate the push button switch I22 which serves through the time delay relay I to deenergize the solenoid 8| and thus allow the released compression of the spring 80 to shift the valve 64 into the position shown in the drawings so that the grinding wheel I2 will move rapidly to its rearmost inoperative position.

In accordance with this invention a lapping head I30 is mounted on the wheel slide II. The lapping head I30 includes one or more abrasive sticks I3I, which are mounted so that they may be reciprocated lengthwise of the work piece 25 as the latter is rotated. The abrasive sticks I3 may be of suitable abrasive material, such as crystalline alumina or silicon carbide bonded with various types of bond, such as resinoid or vitrified ceramic material. The lapping head I is supported by means of a bracket I32 which is provided with elongated slots I33 and I34. The bracket I32 is adjustably fastened to a transversely movable slide I35 by means of a pair of clamping bolts I36 and I31. The clamping bolts I36 and I31 pass through the elongated slots I33 and I34 and are screw threaded into a portion of the transversely movable slide I35. The slide I35 is provided with a dovetailed slide way I38 which mates with a correspondingly shaped dovetail slide way formed on a bracket I39, which is fastened to the upper surface of the wheel slide II. By means of the clamping bolts I36 and I31, the lapping head may be adjusted longitudinally relative to the work piece 25 to position the lapping sticks I3I in the desired position relative to the work piece 25. By means of the slide I35, the lapping head I30 may be adjusted transversely relative to the machine, so the lapping sticks I3I are in the desired relationship with the axis of the work piece 25. The slide I35 is provided with elongated slots I40 and MI and is arranged to be clamped in adjusted position on the bracket I39 by means of clamping screws I42 and I43. The bracket I32 has a fiuid pressure operated cylinder I44 formed integral therewith. The cylinder I44 is provided with a dovetailed slide way (not shown) which mates with a dovetailed slide way I45 formed on the vertically movable lapping head I30. A slidably mounted piston I46 is-contained within the cylinder I44. The piston I46 is connected by a piston rod I41, the upper end of which is fixedly mounted to a bracket I48 fixedly mounted on the upper end of the head I30.

When fluid under pressure is admitted through a pipe I49 into the cylinder chamber below the piston I46, the piston I46, together with the lapping head I30 will be moved vertically to an inoperative position with the lappings sticks I3I out of operative engagement with thework piece 25. Similarly, when fiuid under pressure is passed through a pipe I50 into a cylinder chamber above the piston I46, a downward movement will be imparted to the piston I46 and the lapping head I30 to move the head I30, together with the lapping sticks I3I into an operative position with the lapping sticks I3I in operative engagement with the surface of the work piece to be lapped.

The lapping sticks I3I are mounted on a holder I5I which is pivotally upported by means of a stud I52 carried at the lower end of a pivotally mounted rock arm I53. The rock arm I53 is pivotally supported to swing about the axis of a vertically movable roller I54. The roller I54 serving as a pivot point for the rock arm I53. The upper end of the rock arm I53 is arranged to be oscillated by means of a fluid motor I55 to be hereinafter described.

In order that a straight line reciprocatory movement may be imparted to the lapping stick I3I and the holder I5I, a modified oscillating movement is imparted to the rock arm I53. A cam I56 which is fixedly supported relative to the vertically movable head I30 is engaged by a roller I51 which is rotatably supported on the rock arm I53. The shape of the cam I56 is such that during the oscillation of the rock arm I53 by the fluid motor I55, a slight vertical motion is imparted to the rock arm I53 so that the lapping sticks I3I are maintained in uniform operative engagement with the periphery of the work piece 25 and the lapping sticks I3I are reciprocated in a straight line path, in a direction parallel to the axis of the work piece 25.

The fluid motor I55 preferably comprises a fiuid pressure cylinder I60 which contains a slidably mounted piston I6I which is connected by means of a piston rod I62 with a collar I63 which is pivotally connected by means of a stud I64 'to the upper end of the rock arm I53.

The collar I63 extends upwardly and is arranged in the path of a pair of adjustably posi tioned spaced collars I65 and I65a which are adjustably supported on a valve stem I66 of a pilot valve I61. The pilot valve I61 is provided with a hollow cylindrically shaped aperture which contains a slidably mounted shuttle-type reversing valve I68. When fluid under presure is admitted through a pipe I69, it passes through a normally closed stop and start valve I10 and through a pipe I1I into the valve I61 so as to produce a continuous reciprocatory movement of the piston I 6| which in turn imparts a oscillatory movement to the rock arm I53 to reciprocate the lapping sticks I3I. The motor I55 has not been described in detail, since this motor is identical with that shown in the United States patent to Wallace H. Wood No. 2.212.871 dated August 27, 1940, to which reference may be had for details of disclosure not contained herein.

It is desirable that the motor I56 be automatically started when the lapping head I30 is moved toward an operative position and automatically stopped when the lapping head I30 is moved to an inoperative position. This is prelerably accomplished by means of the start and stop valve I10 which is provided with an actuating arm I12 having a roller I13 mounted at its lower end. The roller I13 isarranged in the path of a cam I14 which is fixedly supported on the bracket I32. It will be readily apparent from the foregoing disclosure that when the head I30 is moved downwardly the actuating roller I13 is moved into engagement with the cam' I14 which serves to rock the arm I12 in a clockwise direction to open the valve I and thus start the reciprocatory movement of the piston I6I which in turn imparts a reciprocatory movement to the lapping sticks I3I prior to their engagement with the peripheral surface of the work piece to be lapped. g

Similarly when the head I30 is moved upwardly to ,,an inoperative position, the roller I13 rides up the surface of the cam I14 thus allowing the part of the operator after the grinding operation has been completed and the lapping operation continues for a predetermined and definite arm I12 to rock in a counterclockwise direction to close the valve I10 and thus stop the motor I55 to' stop the reciprocatory movement of the lapping sticks I3I when the head is moved to an inoperative position after a lapping operation has been completed.

It is desirable that the movement of the lapping head I30 to and from an operative position be automatically controlled in timed relation with the grinding operation so that the lapping head I30 is maintained in an inoperative position during the grinding operation after which the head automatically is moved into an operative position and a lapping operation for a predetermined time interval is provided. i

In order to accomplish this result, a piston type control valve I15 is provided. This valve I15 comprises a valve stem I16 having formed integrally therewith a pair of valve pistons I11 and I18. The valve stem I16 is normally held in its left-hand end position by means of a compres-- sion spring I19. A pull-type solenoid I80 is provided to shift the valve stem I16 into its righthand end position (Fig. 2). Fluid under pressure from the pump 62 passes through a pipe I8I 'into a valve chamber I82 located between the time interval governed by the setting of the time I relay I85.

r The operation of this improved grinding and lapping machine will be readily apparent from the foregoing disclosure. Assuming all of the adjustn'ients to have been previously made for the grinding and lapping of a. work piece 25, the work piece 25 is placed in position on the headstock center 23 and rootstock center 24. The control lever I20 is then rocked in a counter-clockwise direction (Fig. 2) to initiate a grinding cycle. The movement of the control lever I24, as previously described, serves to close the switch I23 which in turn sets the time relay I20 in motion andat the same time energizes the solenoid M to shift the grinding feed control valve 64 toward the left (Fig. 2) to start the movement of the piston 52 toward the left. The wheel slide II and grinding wheel I2 advance toward the left (Fig. 2) to grind the work piece piece 25 to the required and predetermined size which operation continues for a predetermined and definite time interval as governed by the time relay I20. The infeeding movement continues until the stop collar II5 engages the stop surface II4 after which 7 set the time relay I85 in motion and simultaneously to energize the solenoid I80 so as to admit valve pistons I18 and I11 and in the position shown in Fig. 2 passes outwardly through a pipe I50 to the cylinder chamber above the piston I46 to initiate .a downward movement of the lapping head I30. The rear end of the piston rod 53a is provided with a detent I83 which i arranged to actuate a normally open limit switch I84 when the grinding wheel I2 and the wheel slide II are moved'to a rearward or inoperative position.

The closing of the limit switch I84 serves to set a Microflex electric time relay I85 in motion and at the same time serves to energize the solenoid I 80 to position the valve I15 as illustrated in-Fig. 2' so as to admit fluid to the cylinder chamber above the piston I46 to initiatea movement of the lapping head I30 into an operative position. The time relay I85 is adjusted sothat the lapping operation will be carried on for a predetermined time interval, after which the tripping of the time relay I85 will de-energize the solenoid I80 and thus release the compression of fluid under pressure to produce a. downward movement of the lapping head I30. During the downward movement of the lapping head, I30, the roller I13 engages the cam I14 which movement serves to open the stop and start valve I10.

The opening of the, valve I10 admits fluid under pressure to start the fluid motor I55 to impart a reciprocatoryi movement to" the lapping sticks I3I just before the lapping sticks I3I engage the peripheral surface of the work piece'to be lapped.

The lapping operation continues for a predetermined time interval as governed by the time relay I85. When the time relay. I85 trips, itopens a circuit to de-energize the solenoid I80'thus releasing the compression of the spring I19 to shift the spring I18 to shift the valve I15 into its reverse position. This movement serves to admit fluid under pressure into the cylinder chamber below the piston I46 to raise the lapping head I30 to an inoperative position, during which movethe valve I15 into its reverse position and thereby to move the lapping head I30 upwardly to an inoperative position. During the movement of the head I30 to an inoperative position, the valve I10 closes, thus stoppin the fluid motor I25 and the reciprocatory movement of the lapping sticks I3I.

A sn'ap switch I86 is provided to render the time r'elay I inoperative in case it is desired to utilize the mechanism for a grinding operation only.

It will be readily apparent from the foregoing disclosure that the improved grinding machine is arranged automatically to grind a work piece for a predetermined grinding operation after which a predetermined lapping operation is automatically initiated so that the work piece 25maybe wheel I2 and its supporting ground and thereafter lapped automatically without attention on the part of the operator.

It will thus be seen that there has been provided by this invention apparatus in which the various objects here and above 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 limited sense.

I claim:

1. A grinding and lapping machine comprising means for rotating a cylindrical work piece, a grinding wheel, a wheel slide therefor, hydraulically operated means for moving the wheel toward and from the work, a lapping stick, means for oscillating the lapping stick along an element of the work, a hydraulically operated mechanismfor vmoving the lapping stick into contact with the rotating work, means including a control valve to control the movementrof the grinding wheel toward and from the work, and means including a second independent control valve which is automatically actuated when the grinding wheel moves to an inoperative position to initiate an approaching movement of the lapping stick.

2. In a grinding and lapping machine havin a rotatable work support and a rotatable grindin wheel, a transversely movable slide to support said wheel, a feeding mechanism to feed the slide toward and from the work support to grind a work piece, a reciprocable lapping stick, positioning means to move said lapping stick toward and from the work support, a motor to reciprocate said lapping stick, means actuated by the movement of the stick toward an operative position to start said motor, and means automatically actuated when the wheel slide is moved into an inoperative position after a grinding operation to actuate said positioning mechanism to initiate to means for rotating a cylindrical work piece, a

grinding wheel for grinding the same, a wheel slide, manually operated machanism for positioning the wheel relative to the work, hydraulically operated mechanism for moving the wheel slide and wheel toward and from the work, a lapping stick arranged to contact with the rotating work, hydraulically operated mechanism for moving the lapping stick toward and from the work, hydraulically operated mechanism for oscillating the lapping stick in lapping contact with the work, and means including a control valve which is actuated automatically when the grinding wheel is moved to a rearward position after a grinding operation has been completed automatically to initiate a movement of the lapping stick into operative \lapping contact with the work for a lapping operation.

4. In a grinding and lapping machine having a rotatable work support and a rotatable grinding wheel, a transversely movable slide to support said wheel, means including a piston and cylinder to feed said slide toward and from the work support to grind a work piece, a lapping head including a reciprocable lapping stick, positioning means including a piston and cylinder work support, a fluid motor to reciprocate said is actuated by movement of the wheel slide to an inoperative position to admit fluid under pressure to said lapping stick positioning cylinder automatically to initiate a lapping operation after a grinding operation has been completed. 5. A grinding and lapping machine comprising 7 a grinding wheel and means associated therewith for rotating 9. work piece and grinding a cylindrical surface thereon, a slide carrying said wheel, mechanism for moving the slide to position the wheel in contact with the work, an abrasive lapping element, a separate mechanism for moving said element into contact with the work, means automatically actuated by movement of the grinding wheel to an inoperative position after a grinding operation to initiate an approaching movement of the lapping element to move it into operative engagement with the work piece for a lapping operation, and means automatically actuated by and in timed relation with the approaching movement of the lapping element to initiate a reciprocatory movement thereof. r

6. In a grinding and lapping machine having a rotatable work support and a rotatable grinding wheel, a transversely movable slide to support said .wheel, a feeding mechanism to feed the slide toward and from the work support to grind a work piece, a lapping head including a reciprocable lapping stick, means includinga fluid motor to move said stick toward and from the work support, a fluid motor to reciprocate said lapping stick, a valve actuated by movement of the lapping stick toward said work to start said lapping stick reciprocating motor, and means including a valve which is actuated in timed relation with movement of the wheel slide to an inoperative position to admit fluid to said first fluid motor to initiate a lapping operation.

'1, In a grinding and lapping machine having a rotatable work support and a rotatable grinding wheel, a transversely movableslide to support said wheel, a feeding mechanism including a piston and cylinder to move said slide toward and from said work support to grind a work piece, a lapping head including a reciprocable lapping stick, positioning means including a pis-- ton and cylinder to move saidlapping, stick toward and from said work support, a solenoid actuated valve to control the flow of fluid under pressure to and from said latter cylinder, an electric time relay to control said valve, and means including a switch actuated by movement of the wheel slide to an inoperative position au-- tomatically to energize said solenoid and set said time relay in motion so as to initiate a predetermeans including a piston and cylinder to move to move said lapping stick toward and from said lapping stick, and means including a'valve which said lapping stick toward and from said work support, acontrol valve therefor; means including an electric time relay to control said valve, and a switch actuated by movement of said wheel slide to an inoperative position to set the time relay in motion and to actuate said valve 'so as to initiate a predetermined lapping operation.

RAYMOND A. COLE.

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