US1893083A - Lapping machine - Google Patents

Description

Jaim., 3, B933.

H. s. INDGE ET Al.

LAPPING MACHINE Filed Sept. 20. 1929 5 Sheets-Sheet 1 Mmmm 5. Indy@ y@ Player Qmmwm Herber ydne 5am. 3, 1933. H, 5 INDGE ET AL ,893,083

LAPPING MACHINE Herer 5, nco@ .Srgdngg P/slyew Jamo 19o H. s. INDGE ET An.

LAPPING MACHINE Filed Sept. 20, 1929 5 Sheets-Sheet 5 jmmmm, Herber S. [no'fpe Sfgdny P/ger' Jam. 3, i933., H s, |NDGE -r AL y ,893,083

LAPPING MACHINE Filed Sept. 20, 1929 5 Sheets-Sheet 4 Herben 5. Indpoe rgdwedg P/aryer' Jan. 3, i933. H. s. :NDGE ET Al.

LAPPING MACHINE 5 Sheets-Sheet 5 Filed Sept. 20, 1929 I8y :Jmuenow Hemer? 3. Indge @SrS/ngy P/yer Patented lam 35, 1933 HERBERT INDGE AND SYDNEY PLAYER, 0F WESTBORO, MASSACHUSETTS, ASSIGNORS TO NORTON COMPANY, 0F WORCESTER, MASSAmUSETTS, A CORPORATION OF MASSA- CHUSETTS LAPPING Application filed September rl`his invention relates tolapping machines and more particularly to a lapping machine for lapping the periphery of an irregular article, such as the bearings of a crankshaft, a cam or camshaft, and other objects having surfaces which are irregularly shaped or are not concentric with their axes of rotation.

l-Ieretofore, various machines have been devised forlapping work pieces, such as crankshafts, which have comprised a pair of nonrotatable lapping blocks clamped about the periphery of the portion to be lapped and a mechanism for rotating and vreciprocating the Work piece to produce the required lapping action. In a previous machine of this type, such as is shown in the patent to Player No. 1,711,061 dated April 30, 1929, the lapping operation was controlled in accordance with the guesswork of the operator; that is, the operator lapped the shaft for a given length of time and then removed the lapping elementsI from contact with the Work and examined and measured the same to determine how much further the operation should be carried on; and this was repeated until the product appeared satisfactory. T his type of machine depends solely on the skill of the operator. and the cut and try method, hence it causes considerable loss of time and a consequent impairment of the efficiency of the machine.

Itis the primary object of this invention to eliminate such difficulties and to provide a machine for lapping an irregular article with an automatically actuated mechanism for stopping the lapping operation after the consummation of a` predetermined operating condition, such as after a definite period of lapping.

A further object is to provide a machine of this type in which a multiplicity of surfaces may be lapped at the same tinie and in which the stopping mechanism operates in timed relation with the relative lapping movement of the Work and the laps.

It is another object of this invention to provide a suitable adjustment for the timing mechanism so that the operator may manually adjust the period of lapping, when he sets up the machine for a given operation.

MACHINE 20, 1929. Serial No. 394,072.

In the lapping of heavy pieces of Work, such as crankshafts and camshafts, it is often diiiicult and wasteful of energy and time for the operator to lift the heavy piece to and from an operating position relative to the supporting and rotating mechanism before and after the lapping operation is completed.

It is therefore another object of the present invention to provide a machine in which the operator may place a Work piece to be lapped in the machine With a minimum amount of exertion, and in particular to provide a suitable Work positioning power mechanisni'which is so located and constructed that the operator may readily move the Work into operating position on the machine and in alignment with the Work supporting and rotating members.

In previous lappingmachines of the type shown in said prior patent, the arms carrying the lapping members have been pivotally mounted in such a Way that their Weight has produced a thrust on the Work piece and this has tended to cause an unequal Wear of the lapping elements as Well as to affect the running balance and operation of the mechanism.

It is is a still further object of this invention to overcome thisdifliculty and to provide a construction in Which the lapping arms are counterbalanced so as to minimize the thrust of the lapping member on the Work piece.

Moreover, in such machines it has been necessary for the operator to swing each of the lapping members separately into operating contact With the portion of the Work to be lapped. A crankshaft having a plurality of portions to be lapped required the consummation of considerable time and effort on the part of the operator, and so slowed down the production of the machine.

It is a further object of this invention to overcome this problem and to provide a suitable locking device so arranged that each of the lappingelements may be locked in an indexed position Where it is in alignment With a corresponding portion of the Work to be operated upon.

It is a still further object of this invention to provide a clutch controlled speed changy has been illustrated as embodied in a machine' for lapping a crankshaft, although it is to be understsood that in certain aspects the invention is broadly applicable for use with other articles which have either a single or a plurality of surfaces or portions to be finished.

Fig., 1 is a front elevation of a machine for lapping crankshafts, having parts broken away to more clearly show the operating mechanism;

Fig. 2 is an end view of the machine having a portion of the headstock and base broken away to show the driving mechanism;

Fig. 3 is a cross sectional view through the machine, taken approximately on the line 3 3 of Fig. 1;

Fig. 4 is a fragmentary diagrammatic perspective view of the operating parts in the headstock showing the work rotating and reciprocating mechanism and the timing mechanism;

Fig. 5 is a cross sectional view through the headstock on an enlarged scale, taken approximately on the line 5 5 of Fig. 2;

Fig. 6 is a horizontal cross sectional view on an enlarged scale, taken approximately on the line 6 6 of Fig. 2;

Fig. 7 is a similar cross sectional view on an enlarged scale, taken approximately on the line 6 6 of Fig. 2, but with parts broken away and shown in section to more clearly illustrate the timing mechanism;

Fig. 8 is a cross sectional view of a portion of the headstock on an enlarged scale taken approximately on the line 8 8 of Figs. ,6 and 7;

` Fig. 9 is a fragmentary sectional view on an'enlarged scale taken approximately on line 9 9 of Fig. 7;

Fig. 10 is a horizontal sectional view through the footstock taken approximately on the line 10 10 of Fig.y 1; l

Fig. 11 is an enlarged detail view of the parts of the locking mechanism which are arranged to lock the lapping arms in indexed position; and

Fig. 12 is a cross sectional view taken approximately on the line 12 12 of Fig. 11.

In accordance with this invention, a machine has been provided for lapping ory grinding the surface of an irregular article, such as a. cam or the pins on a crankshaft or other shape of article, the surface of which is not concentric with its axis of rotation. The machine comprises primarily supports for the Work and a. lapping member engaging the` so that the work may be rov surface to be operated upon and mechanism for relatively rotating the Work andthe lapping member. As an aid to the lapping operation, it is preferable that the members be reciprocated relatively. .If the article to be lapped has a plurality of Work stations thereon, such as is found on a. crankshaft, it is preferable to both rotate and reciprocate the consummation of a predetermined operating condition, and this may be accomplished by means of a timing mechanism which is connected to stop the lapping operation after a predetermined time period. In the preferred construction the timing mechanism is operated in timed relation with the relative rotation or reciprocation of the Work and the lapping member o'r members so that this relative motion is stopped after a predetermined cycle of operations, such as a predetermined number of revolutions of the work piece.

In the specific typeof machine illustrated for lapping the pins on a crankshaft, the lapping device may be constructed as shown in said patent to Player, in which the lapping y members are held on.al movable arm in such a manner that as the work revolves they will remain in contact with the Work and follow its contour. The weight of the arm is preferably counterbalanced by a suitable device so as to minimize or regulate the thrustof the lapping member on the work. Also, a suitable locking device is provided so that each lapping arm may be clamped in an indexed position relativeto the corresponding position of the work to be lapped thereby, and the parts are so arranged that. when a crankshaft is replaced in the machine, all of the lapping members are properly located so that the crankpins may be put into position and the laps clamped in place without having to adjust their positions further. Also,f,a loading device may be provided tolift orotherwise move a heavy piece of work into Vposi-l tion relative to its support so that it ma be easily/handled by the operator. A cranks aft is ordinarily mounted onhead-andtail stocks having driving and supporting members, and

in this type of machiney thecrankshaft is moved into place in alignment between `these members and there suitably clamped. in. position. yAs illustrated in the-udrawings .a crankshaft lapping machine mayicomprise-abase 11 which serves as a support fora headstock 12 and a footstock 13 arranged tosu'pporha work piece 14 for rotation.ahoutyitsgaxis The lapping members 15 may be constructed and arranged as shown in said prior patent, and these are pivotally supported on the frame 16 which is in turnvrigidl fixed to the base 11. These lapping mem ers are arranged to engage and clamp around the peh ripheries of a plurality of portions on the work piece so that they may be simultaneously lapped if desired.

War/cv rotating and reciprocating mechanism A' suitable headstock mechanism is provided so that the work piece 14 to be lapped may be rotated and reciprocated for a variable but predetermined time to produce the 5 desired lapping faction on the Work piece.

rlhe Work piece is supported at one end by a rotatable sleeve which is slidably mounted within the flange 22 projecting from the headstock 12. A spindle 23 is rotatably mounted o in the bearing 24 at one end and bearings 25 at the other end and is arranged to transmit a rotary motion to the sleeve 20 by means of a pin 27 which is fixed relative to the sleeve 20 and passes through an elongated slot 28 Within' a disk-shaped projection 29 on the end of the spindle 23. A. work driving pin or dog 30 is fixed to the pin 27 and passes through an aperture in the projection 29. rlhe pin 30 engages a plate 31 affixed to an end of the work and serves as a driving member to rotate the work piece relative to the lapping members. The pin 27 is arranged so that it may be retracted to telescope the sleeve 20 and the driving pin 30 within the flange 22 to permit placing a piece of work into the machine and then sliding the sleeve 20 and the driving pin 30 into operative relation with the Work. The driving pin 30 is moved relative to the spind1e'23 by means of a rod 32 which is slidably mounted within a central aperture in the spindle 23 and is normally held biased to an operating position by a spring 33 which engages a shoulder within the spindle 23 and a shoulder on the rod 32. 5 The movement of the rod 32 may be controlled by any suitable mechanism, such as a manually operable lever 35 pivotally mounted in the front of the machine base. This lever is connected to the forward end of a 0 shaft 36 which has on its other end a projecting arm 37 adapted to engage the surface of a yoke 38 mounted on a shaft 39. The

yoke 38 engages an annular groove 40 in a sleeve 41 which is in turn connected by a pin 5 42 with the reduced portion 43 of the rod 32. The pin 42 passes through an elongated slot 44 in the reduced portion 46 of spindle 23 so that the movement of the yoked member is transmitted through the sleeve 41 and pin 42 to move the members 20, 27 and 30 endwise as desired.

'llo produce the desired lapping action, it is necessary for the work to be reciprocated relative to the lapping members while they 5 are relatively rotated. To permit the reciprofto rotate the s cation of the spindle 23 and at the same time provide a driving connection with the work piece, it is necessar to provide a suitable yieldin connection etween the s indle and the col ar 41 so that the driving og 30 will always be maintained in operative engagement with the work during reciprocation thereof. To accomplish this, sleeve 45 is secured to the reduced portion 46 of the spindle 23 and is provided with an outwardly extending flange to take the thrust ofthe spring 47 in one direction while an inwardly projecting ange on the sleeve 41 serves to engage the opposite end of the spring so that the tension of the spring is at all times maintained to hold the spindle 23 in a direction toward the right, as shown in Fig. 5, and thereby maintain the driving dog 30 and the sleeve 20 in proper driving and supporting contact with the work during the lapping operation while the work is being rotated and reciprocated.

The spindle 23 may be rotated by any suitable mechanism, such as a worm gear 50, which is mounted on a sleeve 51 rotatably supported by the bearings 25. The sleeve 5l is slidably keyed to the reduced portion 46 of the spindle 23 by means of akey 53 so as to rotate the spindle 23 while it is being reciprocated. The Worm gear meshes with a Worm 54 which is keyed to a cross shaft. The shaft 55 is rotated by a suitable driving mechanism, such as a motor 60, which is pivotally mounted in the base of the machine. The motor is connected by a link chain or driving belt 61 to rotate a pulley 62 on the shaft 63. The other end of the shaft 63 is provided with a gear 64 connected by a link chain 65 with a gear 66 on the end of the cross 'shaft 67. 'llhe shaft 67 is connected with the shaft 55 by a suitable gear mechanism to rotate the shaft and the spindle 23 at the desired speed. As illustrated in the drawings, the shaft 67 is provided with gears 68 and 69 meshing with gears 70 and 71, respectively, which are freely rotatable on the shaft 55. Either of the ears 7 0 or 71 may be connected haft 55 at a slow or a fast speed respectively by engaging a clutch member 7 2 with the clutch teeth 73 on the gear 70 or the clutch teeth 74 on the gear 71. The clutch member 72 is slidably keyed to the shaft 55 and may be shifted by any suitable mechanism, such as by means of a yolred member 75 having projecting pins 76 engaging an annular groove 77 in the clutch member 7 2. The yoked member 75 is mounted on a vertical shaft 79 which may be rocked by a manually operable lever 30.

The clutch may be held in neutral position by swinging the manual control lever 80 so that an arrow point 31 on an arm 32 will engage a correspondingly shaped recess 33 in a pivotally mounted lever 34. A pair of springs 35 and 36 are connected to the lever .82 at their inner ends and to fixed studs 87 To attain the primary object of this inventlon, namely, to provide a suitable timing mechanism to control the extent and duration y of the lapping operation, suitable connections are rovided so that the clutch member 72 may automatically disengaged after a predetermined number of rotations of the work piece. As illustrated, this timing mechanism ,may comprise a gear 90 mounted on a reduced portion 91 of the shaft 55. The ear 90 is keyed to the shaft 91 and meshes with a pair of tumbler gears 92 and 93 which are rotatably supported on studs 94 and 95 respectivelyon the' tumbler frame 96. The frame 96 is supported to rock on the shaft 91. The stud 95 also supports a gear 97 which is keyed to 4rotate with the gear 93 and is arranged to rock into or out of engagement with a ,gear 99. The latter is provided with an extending sleeve 100 which is rotatably mounted in suitable'bearings 101 in the frame 12 of the headstock. A manually operable lever 102 is mounted on the end of the frame 96 so that the frame 96 may be rocked to mesh. either the gear 92 or the gear 97 with the gear 99 .to'p'roduce either a fast or a slow speed of rotation of the gear 99.

An eccentric portion 103 is provided on an extendingportion of the gear 99 which is engaged by an eccentric strap 104. A pawl 105 is mounted on a stud 106 on the other end of the strap. The pawl 105 engages the teeth of a ratchet wheel 107 which is mounted on the end of a shaft 108. A cam 109 is mounted on the shaft 108 and is engaged by a follower 110 keyed to a shaft 1 11. The shaft 111 is mounted in suit-able bearings 112 in the headstock frame 12 and servesas a support to rock the lever 84. The cam 109 is so shaped that after a predetermined number of teeth on the ratchet wheel 107 have been picked. by the pawl 105 a high portion of the cam 109 will rock the follower 4110 and also the 'shaft 111 and thereby rock the lever 84 to swing the projection 83 toward the right, as viewed in Fig. 4, and thereby permit the released ten.- sion of the vspring 86 to, throw the lever 82 and clutch 72 intoa neutral position and stop the rotation and reciprocation of the'work 1ece. p It will be readily apparentfrom this construction, that the operator may swing the lever 80 toward the right into the position shown in Fig. 4to engage the clutch member 72 with the clutch teeth 7 3 and move the parts into the positions illustrated. The rotation and reciprocation of the lapping members is then started and continued until the cam 109 rocks the follower 110 after a predetermined number of reciprocation's of the strap 104, and

V1,:saaose end of the shaft 109 so that the operator inay readily rock the lever 84 manually to release the lever 82 and permit the spring to throw the clutch member 72 to a neutral position at any time during the'cycle of operation desired. f

To permit varying the cycle of operations,

so that the period of lapping maybe varied according to the desires of the operator, a shield 114 is mounted on the support 115 which is rotatably mounted on the shaft 108 and is arranged to surround a portion of the ratchet Wheel 107. The operator may readily adjust the position of the shield 114 so that one or more teeth of the ratchet may be picked up at each recprocation of the strap member 104. The number of teeth picked up at each reciprocation will vary the speed at which the cam 109 is rotated and consequently vary the timing of the cycle of the lapping operation.' A manual controlvlever 116 is mounted on the outer end of the support 115 so that the operator may readily turn the shield 114 from the operating position in front of the machine. The lever 116 gnis provided with a suitably graduated scale 117 and a fixed portion ofthe headstock 12 with an index point 118. The operator may, by

manipulation of this manual control, turn the g shield to produce the proper timlng of the lapping cycle.

In the lappig of a' fcylindrical member where the lapping member clamps around the periphery of the object to be lapped, as shown in the Player patent, it is essential that the members be given a combined relative rotating and reciprocating motion to produce the desired lapping action. An eccentric pin 120 s held in fixed relation with the gear 99 during rotation thereof. A connecting rod 121 surrounds the eccentric pin 120 at one end and is connected at the other end to the projection 122 of ayoked member 123 which engages the pins 124 in the member 125 mounted on a ball bearing 126 xed on the wheel spindle 23 so that the member 125 is held against,

rotation by engagement of the pins 124 with projections of the yoked member 123 while the spindle rotates. The parts' are arranged so that movement of the yoked member 123 axially of the spindle 23 is transmitted to reciprocate the work piece 14. As the 'spindle 23 is rotated during vthe lapping operation, the shaft 55 through the gear mechanism rotates the gear 99 and revolves the eccentric pin 120 to simultaneously reciprocate the spindle 23 and the work piece 14. f\

For certain types of-work, it isdesirable that the extent .of reciprocating motion be adjustable so as to obtain the desired lapping action. To accomplish this, the`p1n 120 may aeeesoee be mounted on an eccentric stud 127 which is journaled within a hole 128 in the sleeve 100.

' The pin 120 is eccentric to the stud 127 and the The footstock end of the work is supported by a center 21 mounted on the outer end of a live spindle 14() so that the spindle and center rotate freely as the shaft is rotated during the lapping operation. Due to the reciprocation of the work piece during the lapping operation, it is essential that the center 21 be maintained in contact with the end of the Work piece with suiicient pressure to properly support the work. As illustrated in F ig. 9 of the drawings, a spring 141 surrounds the spindle supporting sleeve 142 and is arranged to exert a pressure suiiicient to lhold the center 21 in operative engagement with the work. A suitable lever 143 and toggle lconnection v144 is provided to move the sleeve 142 longitudinally to retract the center from its operating position when it is desired to replace the crankshaft after the lapping operation has been completed.

.Zapping arms To produce the desired lapping action on the work piece, which has a plurality of spaced portions to be lapped, itis preferable to provide a plurality of lapping arms. arranged to simultaneously engage the various portions to be lapped so that the entire work piece may be lapped at one operatlon. The lapping members and the work piece are rotated relative to each other as well as. reciprocated relatively to produce the desired lapping action. As shown in the drawings, a mechanism has been illustrated for lapping crankshafts in which the main and crankpin bearings are slmultaneously la ped. The lapping members are mounted on reely movable arms and the work 1s rotated and reciprocated relative to the lapping members. A plurality of lapping arms 150 are provided and arranged to engage the main bearings 151 which are concentr1c with the axis of rotation. A second set of arms 152 is arranged to engage the crankpins 153so that both the crankpins and the main bearings of ,the shaft may be simultaneously finished or Y lapped. The lapping members may be of any suitable construction in which a lapping member is held in clamped engagement around the periphery of the work during the relative rotation and reciprocation, but are illustrated similar to the showing in the prior patent to Player No. 1,711,061 in which a plurality of lapping elements 155 are arranged to clamp around the work piece at opposite points. The lapping members are mounted on pivotally supported arms 156 and 157 which are pivoted to the lapping arms 150 and 152 respectively. These arms are moved to and from an operating position by manually operable levers 158 which actuate toggles 159 to lock the lapping members rigidly in engagement with the work.

The lapping arms 150 which are arranged for engagement with the main bearings 151 require no swinging movement since the main bearings are concentric with the axis of rotation of the crankshaft. These arms are supported on a shaft 160 which is supported in the frame 16. The arms 150 are guided by projecting arms 162 which engage a second guide rod 163 also supported in the frame 16. This extension of the arm 150 is slotted and provided with suitable clamping screws so that they may be adjusted longitudinally of the machine into alignment with the main bearings and then locked in adjusted position. The arms 152 which carry the lapping members engaging the crankpins 153 are supported by pivot pins 165 on the forward end of pivotally mounted levers 166 which are supported on a shaft 167 journaled in the frame 16.

ln order to attain a further object of the invention, namely, to Aminimize the weight and. thrust of the lapping members on the work as they are relatively rotated, each arm 166 is provided with. a projecting arm 168 which extends diametrically opposite the arm 166. This arm is provided with a suitable weight 169 which may be adjusted-relative to the arm 168 to serve as a counterbalance for the arm 166 and the lapping arm 152. Each of the lapping arms 152 is supported by an independent arm 166 and each arm 166 in turn freely rotatable on the shaft 167 and provided with counterbalance weights 169. This construction permits free movement of the lapping member as the crankpin revolves due to the rotation of the crankshaft.

Locking (Ze/vice for Zapping arms position before and after the lapping operl ation has beencompleted. This mechanism comprises an arm 170 pivotally connected to the lapping arms 152 by a pin 171 and having at its other end an enlarged portion 172 provided with an elongated slot 173. The elongated slot 173 straddles a rectan ularly shaped collar 174 which-lits over a ub on a'lever 175 which at its lower end is provided with a yoked portion 176 engaging a rod 17 7. supported on frame 16. During the normal operation of the machine the arm 170 is freely 'slidable, since the elongated slot engaging the square portion 174 lits freely so as to permit a free movement of the arm 17 0 and arm 152. A nut 178 is provided to clamp thelever 170 to the lever 175 when it is desired to lock the lapping arms. This nut engages a threaded portion 179 on the hub 0f lever 175. By turnin the nut 178, the portion 172 of the lever 170 is clamped rigid v with the arm 174 and thereby holds the lapping arm in its correct position.

In order that all of the arms- 17 0 may be locked simultaneously after the'completion of the lapping operation, a manually operable lever 180 is mounted on the outer end of a 'shaft 181 supported in the frame 16. This convenience of adjustment the keyway and the nut are adjustable. The nut 17 8 is provided with gear teeth 184 on its periphery which are engaged by a spring pressed plunger 185 having projecting teeth 186 arranged to enga-ge the teeth 184 on the periphery of the nut 17 8. The spring pressed plunger 185 is supported in a member 187 which surrounds the shaft 181 and serves as a support for the key 183. It will be readily apparent that any rocking motion ofthe shaft 181 will through the key 183, member 187 and gear 184 turn the nut 178 to either clamp or unclamp the lever 17 0 dependingon the direction the shaft is turned. Each of the arms 152 is provided with a similar clamping or locking device which is supported and-controlled by the shaft 181, so that when the operator swings the lever all of the lapping varms 152 are either simultaneously clamped or unclamped. Ihis permits the operator after completion of one lapping operation to simultaneously lock all of the swinging arms 152 in an indexedposition so that when the next crankshaft is placed in the machine, it will be Inerelynecessary to raise the shaft into position relative to the supporting and driving members and then clamp the lapping members in engagement with the crankpin. flhisj saves the necessityo of having to swing indlvldual lapping heads into and out of operating position.

loading device In previous lapping machines for lapping crankshafts and the like. it has been necessary for the operator to lift the heavy work pieceup and into an operating position relathe drawings, this mechanism ma comprise v a carrier or tray 190 supported on t eposts 191 f and 192 which are arranged to move in a substantially vertical direction to position the work piece in operating position. The tray 190 is provided with work supporting members 193 and 194 which may be V-b1ocks to position the work parallel with lthe work supporting members. It is preferable that the work tray be movedA by a poweroperated mechanism so that it is merely necessary for the operator to place the shaft on the tray and then to manipulate a control to raise it to and from an operating position. Any suitable power operated mechanism may be provided forpraising and lowering the tray 190. As illustrated in the drawings, however, each of the posts 191 and 192 are provided with rack teeth 195 meshing withthe gears 196 and 197 respectively, which are mounted on the ends of a shaft 198. The shaft 198 may be rotated by a gear 199 meshing with a worm 200 on the power shaft 201. The shaft 201 is provided with a pair of pulleys 202 and 203 connected by a cross belt 204 and a straight belt 205 respectively with pulleys 206 and 207 on the shaft 63. Straight and cross belts are provided to give a reverse action so as to permit raising and lowering the tray to and from an Voperating position. A clutch member 208 is interposed between the pulleys 203 and 204 so that either pulley may be locked to rotate the worm 200 and thereby raise or l lower the tray 190. The clutch member 208 is-actuated by a manually operable lever 210 which is connected by a suitable linkage 211 to actuate the clutch. By manipulating the lever 210. the clutch member`208 may be shifted in either direction to lock either of the pulleys 202 or 203 to transmit motion through the shaft 201, worm 200,` gears 190,

196 and 197 to raise or lower the tray 190 as desired.

It is desirable that the upward movement of the tray be limited so that the work piece may be moved into operative position relative to the work supporting heads. To lignit fthe upward movement of the tray 190, a pair of guide rods 215 and 216 are mounted at each' end of the tray 190. These rods pass through the brackets 217 and 218. The lower end of each rod is threaded and provided with nuts justing the nuts 219 and 220, the position of the tray may be varied as desired. v

The operation of the machine will be apparent from the foregoing disclosure. The operator places a crankshaft or other smilar work piece on the supports 193 and 194 of the tray 190 and then shifts the lever 210 to engage the clutch member 208 to lock the pulley 203 into driving engagement with the Worm 200. This rotationof the worm 200 raises the tray 190 until the nuts 219 and 220 engage the projecting arms 217 and 218. The operator then shifts the lever which operates through the connecting parts to slide the sleeve 20 and driving pin 30 into operative engagement with a dog or a projecting part of the work piece. The operator then manipulates the lever 143 to bring the footstock center 21 into operative engagement with the work piece. ln this position the tension of the spring 141 maintains the center in operative contact therewith during rotation and reciprocation of the shaft. VThe opeIator then swings levers 158 on each of the lapping members to clamp them in operative engagement with the periphery of the work, and then by manipulation of the lever 180 rocks the shaft 181 to unclamp all of the lapping heads 152 to permit free movement thereof during the lapping operation. The operator then throws the lever in either direction depending upon whether or not a fast or a slow speed of the work is desired to engage the clutch member 72 with the clutch teeth 73 or 74. As shown in Fig. 4 the clutch member 72 is in engagement withthe clutch teeth 73 to rotate the shaft and the spindle 23 and work piece 14 at the slower speed. This engagement of the clutch rotates the gear 91 and through the tumbler gear mechanism rotates the gear 99 which causes a reciprocating movement to be transmitted to the work piece and simultaneously starts actuation of the ratchet and pawl mechanism which times the cycle of operation. The rotating and reciprocating movement continues until the cam 109 raises the follower 110 and rocks the shaft 111 so that the lever 84 is brought toward the right as viewed in Fig. 4, unt-il the projection 83 on the lever 84 is out of the path of the narrow point 81 on the lever 82 and so as to permit the tension of the spring 86 to move the lever and disengage t-he clutch thereby stopping the cyle of operation. Upon completion of the cycle of operation` the operator first manipulates the lever to lock the lapping arms in their indexed position, then unclamps the lapping members by moving the levers 158. and then by manipulation of the lever 210 brings the work tray into engagement with the work. rlhe lever 143 is then moved towards the right asviewed in Fig. 10 to retract the footstock center 21 and the 65 lever 35 is moved towards the right (llig. 1)

to retract the driving pin 30 and supporting sleeve 20 so thatthe work piece will then rest in the supports 193 and 194 on the tray 190. The operator then shifts the lever 210 in the opposite direction to engage the clutch with the other driving pulley to move the shaft and tray to its lower or inoperative position. In this position of the tray, the operator removes the shaft which has been lapped and places a new shaft in operating position thereon.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A lapping machine for a work piece, the

surface of which is not concentric with its axis, comprising a base, a head stock includinga rotatable spindle and a foot stock on said base to rotatably support the work thereon, a lapping member on said base arranged to engage and follow the work surface during rotation thereof, a power drive including a manually controlled clutch connected to rotate said headstock spindle, and means including a pawl and ratchet mechanism actuated by said power drive to automatically disconnect the clutch and stop the rotation of said work after a predetermined number of rotations'thereof.

2. A crankshaft lapping machine comprising a base, a headstock including a rotatable spindle and a footstock on said base to rotatably support a crankshaft thereon, a plurality of lapping members mounted on said base v arranged to simultaneously engage the main bearings and crankpins of said shaft during rotation thereof, a power drive including a manually operable clutch connected to rotate said headstock spindle, and a timing device including a pawl oscillated by said power drive, a ratchet wheel actuated thereby and a cam rotated by said ratchet which is arranged to disconnect the clutch and stop the rotation of said crankshaft after a predetermined number of rotations thereof.

3. A crankshaft lapping machine comprising a base, a rotatable support for a crankshaft, a power drive to rotate said crankshaft including a headstock and a footstock on said base, means including a crankpin and a conl necting rod to reciprocate said crankshaft relative to the headstock and footstock, a plurality of lapping members arranged to simultaneously engage the main and crankpin bearings thereof, and a gear train rotated by said drive including a double tumbler gear mechanism to produce either a fast or slow reciprocation of the crankshaft.

4. crankshaft lapping machine comprising a base, a rotatable support for a crankshaft thereon, a plurality of lapping members on said base arranged to simultaneously engage 'the crankpins of said shaft, means to hold said lapping members in an indexed position relative to the positions of the corresponding crankpin bearin s on the crankshaft, and power operate mechanism including a movable carrier to move the crankshaft towards its supportJ so that each crankpin is simultaneous y position relative to its corresponding lapping member.

5. A crankshaft lapping machine comprisling a base, a rotatable support for a crankshaft thereon, a plurality of lapping members on said base arranged to simultaneously engage-the crankpins of said shaft, means tov hold said lapping members in an indexed position relative to the positions of the corresponding crankpin bearings onthe crankshaft, power operated mechanism to move the crankshaft into an operating stop arranged to limit said movement when each crankpin is in operative position relative to its corresponding lapping member.

e 6. A crankshaft lapping machine comprising a base, a rotatab e support for a crankshaft thereon, a plurality of lapping members on said base arranged to simultaneously engage the crankpins of said shaft, means to hold said lapping membersinan indexed position relative to the positions of the corresponding crankpin bearings on the crankshaft, power operated mechanism including a movable carrier to move the crankshaft towards its support so `that each crankpin is si.

- multaneously moved-into operative position relative to its corresponding lapping member, and means on the carrier tohold the crankshaft in a definitely located position for en agement by the head and foot stocks.

igned at Worcester, Mass., this 19th day of September, 1929.

SYDNEY PLAYER.

HERBERT S. INDGE.

moved into operative l pos1t1on, and a

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