US2438835A - Cross-feed mechanism - Google Patents

Description

March 30, 1948. H. c. WEQIMVAR 2,438,835

CROSS FEED MECHANISM Filed Jan. 14, 1947 2 Sheets-Sheet 1 March 30, 1948. H. c. WEIMAR 2,438,835

CROSS FEED MECHANISM Filed Jan. 14, 1947 2 Sheets-Sheet 2 Patentecl Mar. 30, 1948 UNITED STATES PATENT" Q-EFFICIE Hans C. Wcimar, Providence, R.- I., ass-ignor to Brown and Shame Manufacturing Company, Providence, R. I., a corporation of Rhode Island ApplicationrJanuary 14, 194 7; SerialNo; 722,002

(Cl.f51-=-165)- 13 C1ain1s. 1 The present invention relates, to an: improved cross feedlmechanism either-general typewhich is actuated by the: reciprocatory movement ofa workl support to effect. stepped cross feeding movements ota tool CaIIIYiRg-LCI'OSS slide against the work. a V

The invention is: particularly; illustrated and described as embodied: 1111B; grinding machine having a longitudinallymovable:work: support, a, headstock and footstock mounted: on: the; work support, a grindingwheel, and a grinding wheel cross slide towhich steppedieedingimovementsw of predetermined iextent are imparted fat: the end 101 the support: travel in either or: both' directions; The. operating and control devicesxfor-the machine include a tablezreversin-gulever shiftableto effect each reversal otwtahlermovement, and a pick cross feedl for moving the grinding, wheel relatively against the: workiincliuding across iced ratchet, a pawl; and connectionscontrolledw by movemet of: the. work supportfor-actuating the pick feed to impart increments; ofi feeding movement' to the grinding wheel: atxthe end of sum port travel in either direction.

It is a principal objectortheinvention toprovidea; novel and improvedmechanismactuated by movement 01: the .worlrsupportfor operating the pick cros-sfeed for the: grinding wheel, which is simple in, construction, accurate-wand pertains-in operation; and. readily adjustable to cause an increment:ofikadvancingmovement ito'be'imparte'd to the grinding :wh'eelat" either or both" limits of supporttraveh a a With this and; other objects: in =view: as. may hereinafter appear a .feature of; the invention consists in the provisionp otya rotatable-prank for effecting the: teedandrrecovcry strokesnoii the cross feed pawl, and connections: from thereversing lever of the machine includingmeansfor adjustment ofusaict connections: so that for one :position of adjustment, movement-of thewreversing lever from one" to the other, position will rotate the crank through an angle ofappz-oxima-teWBfifl degrees, and-ioran alternative-position of adjust-.- ment is effective to rotate the crank-throughan angle of. approxi'n'lately-180- degrees; Inthe illustrated form oiithe invention; theconnectionssfor rotating: the crankv comprisea pair or; toothed racks movable with the reversing;leven'andazpair of pinions which'are connecteditorotate withi the crank and are arrangedtobeselectivelyengaged with the racks. The driving connections include mg the racks andpinions engaging therewith :are constructed: andcrproportioned so; that movement of. the; reversing leverpfrom one tothe other lim itingspositlom is efiectitvel to rotate a the crank through degrees; or; 36Q vdegrees depending upon the position on adjustment otith pinionst Further in accordance with the; m -vention, a locking and control device is provided which is adapted to insure that the-rackandpinionconmotions are maintain-ed at all: timee Ti-n the same phaserelationship: to a one another, The device referred-i to,, 4 provides aninterlocking connection which permitssthe pinions associated with the crank to be shicftedirompne to the other position oiadjustment only for" one predetermined anginlat position of thecrank s 1 a; 1; t l

Further in accordance Wilihgthfi invention, the interlocking i connection referred; to is arranged to-1 permit a ready i adjustment of 3 the pick cross feed to cause: an incremcntwi Irnovement to. be imparted to th-e griildin g wheel selectively,- atone or theother: limitot supportttravelas may be desired. In: order {go-effect such adjustment-of the-picle cross feed, thepinions are first shifted to that position or? adjustment: in which-move ment otthe reversing lever will cause the crank to be driven through an angle of. 360} degrees. The reversing lever is then shifted to the position to which it would be moved by thentable atthat limit oitravel at 'whl-ch thegrinding wheel cross feed ispto take place. The pinions .are then againrshiited to the alternative position of title iustment in which the crank willberotated there by through an. angle cry-180 degrees.-

Furth'er in accordancetwiththe invention, the devicesior eff ectingv-adjustment of the pick cross feed are soconstructed-andi arranged, and the cover which normally encloses these. devices, is so arranged with relation thereto to permit. the cover to be moved toits closed positiononl'y: when the pinions-have been-lfully shifted to one opthe other positionofl. adjustment and are fully meshed with the corresponding rackss Thesevenal features-oi} the invention consist also in the or devices, combinations and arran ement. of parts hereinafter dcscribed andclaimed', which together with: the advantages to be ob-v tained therebywill be readily understoodiby one skilled in the art from v the following; description taken in, connection withi the. accompanying drawings,, in whichulfietlis' a View iniront elevation. of a. grinding. machine embodyingv in: a

preferred: form the several featuresof l the invention; Fig. 2- is a-viewinright-side elevation with portions: of-the base sectioned to illustrate parties ularly the cross feed mechanism of the; achine; Fig-.13 ie-an enlarged detailsectionat view taken onthe-line-Zi-i-ot Flag; F eqf iea'viewot substantially the parts shown in Fig, 3 looking from the right; and Fig. 5 is an enlarged sectional plan view taken on the line 5-5 of Fig. 1.

The invention is disclosed in a preferred form in the drawings as embodied in a grinding machine having a base [0, a work support [2 having mounted thereon a headstock l4 and tailstock l6 and adapted for translatory movement on ways I8, 20 on the base, a cross slide 22, and a grinding wheel 24. As shown in Figs. 1 and 2 the wheel 24 is mounted on a spindle 26 which is continuously driven from a motor 28 through a belt 36 which rides on pulleys, 32, 34 mounted respectively on the spindle 26 and on the armature shaft of motor 28. a

The work support i2 is arranged to be power- 4 will act alternatively through segmental rack 88 and pinion 92 to turn the crank disk 68 through approximately 360 degrees of rotation.

Adjustment of the actuating mechanism above set forth, to obtain a stepped feed of the cross slide at either or both limits of work support movement in accordance with the invention, is obtained by adjustment of the pinions 99, 92 in the following manner. In order to effect a cross feeding movement at both limits of movement of the work support, the pinions 96, 92 are shifted to their forward position so that pinion 92 is en- 7 gaged with the segmental rack 68. The pinion 92 one to the other operating position, will cause operated 'by any conventional means as, for example, by the hydraulic mechanism shown in the.

patent to Maglott No. 2,163,246, issued June 20, 1939. The work support is under the control of a reversing lever 36 which is shiftable by means of reversing dogs 38, 40 from one to the other of two alternative running positions to effect reciprocation of the work support in-the usual manner. r I

The mechanism for feeding the'cross slide 22 and grinding'wheelfl toward the work, comprises a cross feed screw 42 supported at each end in bearings in the base [6, and having threaded thereto a nut carried on a depending lug 46 onthe'cross slide 22. The feed screw 42 is connected-through gears 48, 50 to a cross feed shaft 52 which carries at its outer end a micrometer cross feed ratchet 54. Stepped feeding movementsare imparted to the ratchet and feed screw by means of a pawl 56 carried on a pawl supporting arm68 pivotally supported intermediate its length on the shaft 52. At its outer end the arm Ellis-connected by means of a vertically arranged link 60 to an adjustable crank arm in the form-of a pivot pin 62 carried on a, block 64 adjustably mounted ina radially disposed guide- Way 66 me. crank disk 68. The crank disk 68 is secured to, a rearwardly extending shaft 10 rotatably supported in anti-friction bearings 12, M in the base l6. 4

In accordance with a feature of the invention, novel connections are provided, rendered operative by movement of the reversing lever 36 from oneto the other position to rotate the shaft 19 and crank mounted thereon to impart an intermittent stepped feeding movement to the cross feed mechanism. In accordance with the invention, the driving connections referred to, are constructed and arranged for adjustment to permit such stepped feeding movement to take place at either or both limits of travel of the Work support. The actuating, connections referred to, include an upwardly extending arm 16 which is supported to turn with the reversing lever 36, and is connected through a link 16 with an upwardly extending arm of. an oscillatory actuating member 80, supported to turn on a stud82 carried by a bracket 84 on the machine base. The actuating member 80 is formed at its lower end with two-toothed segmental racks 86, 88 which are arranged for selective engagement respectively with pinions 96, 92 supported as a unit to turn with and to slide axially upon the shaft 16. The parts including the segmental racks 86, 68 and pinions 90, 92 are so proportioned and arranged that movement of the reversing lever 36 from one to the other running position will act through rack 66 and pinion'96 to turr the crank disk 66 through approximately 180 degrees rotation, and

and rack 88 are so proportioned that each successive movement of the reversing lever 36 from the crank disk 68 to be driven through an approximate revolution to retract and thereafter to advance the pawl 56. The sequence of the feed and recovery motions of the pawl .56 at the reversal of the table depends upon the positionof the crank pin 62 relative to the notch in .the crank plate 68 and the center of the plate. It is preferred that the recovery stroke precede the feed stroke in accordance with the illustration of Figs. 1 and 3. With the alternative arrangement, a less desirable condition is set up in which the grinding wheel plunge cuts a substantial distance from the end of the work and then cuts air for part of the return stroke.

In orderto effect a stepped feeding move- -ment of the cross feedat one limit only of the work support movement, the pinions 96, 92 are shifted rearwardly so that the pinion 96 is engaged with the segmental rack 86, these parts being so proportioned that movement of the reversing lever 36 from one to the other position will rotate the crank through degrees only, causing the pawl to be moved either upwardly or downwardly to the opposite limit of its movement. For the position specifically illustrated in the drawings, in which the crank pin 62 is at the top limit of its movement, and the reversing lever 36 is to the right, it will be evident that movement of the reversing lever 36.to the left from the position shown in Fig. 1, as the work support 12 reaches the left hand limit of its travel, will cause the crank to turn through 180 degrees to move the pawl 56 upwardly to thetop of its movement where it is held in stop position. The effect of this motion is to reset the pawl at the left hand limit of the. work support movement. Return movement of the reversing lever at the opposite or right hand limit of table travel will then have the effect of rotating the crank 180 degrees in the opposite direction to its initial position to advance the pawl 56 downwardly, and to'correspondingly advance the cross feed slide.

In the event that it is desired to setup the cross feed mechanism in such a manner as to cause the stepped feeding movement to take place only at the left hand limit of work support travel, the pinions 96, 92 are shifted forwardly when the crank pin 62 is in its extreme high position to engage the pinion 92 with the segmental rack 88. The reversing lever 36 is now shifted leftwardly to the opposite position from 'that limit of its movement, will have theefiect-of feeding the cross ieed pawlifi and cross feed slide while the reverse movement of the lever at'the right hand limit ofsupport movement will have the eiiect of resetting the pawl.-

The mechanism for shifting thegear unit comprising pinions '90, 92 comprises an axially movable plunger 94 supported for axialmovement in a plunger receiving bore 95 formed in the bracket 34 on the base I 9. The plunger is provided at itsrear end with a clutch shifting fork 96 which embraces the gear 90; and at its forward end.

with a knurled manual control head 98. A compression spring I00 coiled'about the plunger 94 between a shoulder l-Glwithin the-plunger receiving bore 95 and a shoulder Ill4formed between the head 98 and reduced stem portion of the Plunger 94 tends to maintain the plunger and associated parts including the gears 99, 92in their relatively advanced position in which the pinion 92 is engaged with the segmental rack 98. A positioned pin 199 secured'to the shifting fork 99 and arranged to slide Within a bore in the bracket 84 serves to key 'theplunger 94 and shifting fork 96 against rotational movement,

Further in accordance with the invention, means are provided for controlling the operation of the cross feed adjusting means above described, including the pinions 99, 92 to maintain the correct operating relationship between the reversing lever 36 and the crank driven cross feed pawl 56. It will be evidentthat'this operating relationship will be maintained only if the shift of the pinions 90, 92 fromone to the other position takes place when the crank is in the same identical position each time the shift is made. In the illustrated formof the invention, the shift is made when the crankpin 62 is in the extreme up position. The mechanism for retaining the correct operating relationship of. these parts, comprises an outwardly. extending flange llil formed on the rear peripheral edge of the crank disk 68. The flange. IIIl isarranged for engagement with either one of two notches H2 and H4 formed in the periphery of the head 99 of the plunger 94. The operative engagement of flange III! Witheitherxof the notch-es H2, H4 serves to lock the plunger in 'the corresponding adjusted position. The flange -I I I! is formed with an arcuate cut-out H6 which-for the extreme upward position of the crank pin 92, is in :alignment with the plunger :94 topermit movement of the plunger from one to the other position. Further, the relationship of the cut-out I I6 to the knurled head 98 of the. plunger is such that the crank cannot be moved irom its extreme up position until after the plunger has been fully shifted and the active pinion fully meshed with its cooperating segmental rack on the actuating member 89, when the flange IIO will have been brought into alignment with the corresponding notch I I2, I I4 of the plunger. The plunger 94 is securely latched in each of its adapted positions by means of a spring-pressed detent pin H8 which is supported for axial movement in a lug I20 on the bracket 84, :and is arranged for engagement with ,either oftwo alternative recesses I22, [24 in the knurled head 98 of the plunger. The detent pin I I8 is provided at its outer end with an enlarged knurled head 126 for convenience of operation byJthe operator.

For the protection of the parts including the crank connection provided by disk 68, pin 62. and link 69, a shield or cover I28ais provided hinged at its lower edge tov turn on lugs I39. The. cover is normally held 'i-n closed position by-means of a spring-pressed detent plunger I 32 which is. mountedin a lug -=I34,=-a-nd is adapted for engagementwith a taperedrecess l-36 'in the side of the coverl28.

iurther safety feature which may serve toindicate tothe operator that the pinions 99, 92 have been -i-ully-shifted from one to the other position, and Whichwill serve as a warning to hirn in the'event that the shift has not been completed, the lock-ing plunger I I 8 including the knurled 'headmi -thereof, is so constructed and arranged withrelation to the cover I28 as to permit the closing of the cover'only when the plunger li8 has been fully seated inoneof the recessesIZZ, I24.

It will be understood that-the invention is not limited to the specific embodiment shown, and that various deviationsmay be made therefrom without departing from the spirit and scope of the appended claims. i

' What is claimed is:

1.- In amachine tool having. a work support adapted fortranslatorytmovement and a tool support adaptedfor cross feeding movement relatively to the Work support the combination of a cross feed mechanism-for the toolsnpporh which comprises :a cross feed screw and nut, a cross feed ratchet and-pawl, a crank connected to reciprocate the pawl reversing. dogs on the work support and a reversinglever actuated thereby, and means controlledtby movement ofandtastool support adapted for. relative tc-andfro'translatory movement andfor relative cross feeding movement, and reversing .means including-a memberushiftable from one to the other of two alternative positions with each reversal of said translatory movement, the combination of a pickzcross feed mechanism comprising a cross feedsratchet, .a pawl, arcrank connected to impart a feed and :recoverymovementyto the pawl for each full 'revol utionpf the crank driving connections from. said-member constructed and having alternative positions oiadjustment to rotate thecrank approximately degrees and alternatively to rotate "the crank approximately 360 degrees with each shift of .said member :from oneto the other position, and means for adjusting said is driving connections.

3. In a machine toolhaving a work support and a toolsupport adapted 'forrel-ative to-andfro translatory movement and for relative cross feeding movement, reversing means including a member shiftable from oneto the other of two alternative positions witheachireversal of said.

approximately 369 degrees with each successive 7 shift of said member from one to the other position.

4. A pick cross feed mechanism for a machine tool having a work support and'a tool support adapted for relative to-and-fro translatory movement and for relative cross feeding movement, and control means including a reversing lever shiftable from one to another of two alternative positions with each. reversal of said translatory movement, which comprises a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, gear connections from said member for rotating the crank including means for adjusting said connections whereby a shifting movement of the reversing lever from one to the other position is effective to drive the crank through one-half and alternatively through a full revolution.

5. A pick cross feed mechanism for a machine tool having a work support and a tool support adapted for relative to-and-fro translatory movement and for relative cross feeding movement, and control means including a reversing lever shiftable from one to another of two alternative positions with each reversal of said translatory movement, which comprises a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, racking means arranged for oscillatory movement with said reversing lever, and a pair of rotary toothed members connected to the crank arranged for alternative engagement with the racking means, said racking means and rotary toothed members being proportioned and arranged to cause said toothed members to rotate the crank through 180 degree and 360 degree angles respectively.

6. A pick cross feed mechanism for a machine tool having a work support and a tool support adapted for relative to-and-fro translatory movement and for relative cross feeding movement, and control means including a reversing lever shiftable from one to another of two alternative positions with each reversal of said translatory movement, which comprises a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, racking means arranged for oscillatory movement with said reversing lever, a pair of rotary toothed members connected to the crank arranged for alternative engagement with the racking means, said racking means and rotary toothed members being proportioned andarranged to cause said toothed members to rotate the crank through 180 degree and 360 degree angles respectively, and shifting means for shifting said rotary toothed members alternatively into operative engagement with said'racking means.

7. In a machine tool having a work support adapted for to-and-fro translatory movement, a tool support adapted for transverse feeding movement relatively to the work support, and control means for the work support including a reversing lever shiftable from one to the other of two alternative positions with each reversal of the work support, the'combination of a cross feed mechanism for the tool support, which comprises a cross feed screw and rrut, a cross feed ratchet and pawl, :a crank connected to reciprocate the pawl, a cross feed actuating member formed. with two separate toothed racks connected for movement with the reversing lever, and a pair of pinions connected to rotate the crank and axially shiftable for engagement selectively with said racks, whereby a shifting movement of the reversing lever from one to the other positionis effective to rotate the crank alternatively through approximate degree and 360 degree angles.

8. In a machine tool having a work support adapted for to-and-iro translatory movement, a tool support adapted for transverse feeding movement relatively to the work support, and control means for the work support including a reversing lever shiftable from one to the other of two alternative positions with each reversal of the work support, the combination of a cross feed mechanism for the tool support, which comprises a cross feed screw and nut, a cross feed ratchet and pawl, a crank connected to reciprocate the pawl, and actuating connections from the reversing lever for rotating the crank alternatively through approximate 180 degree and 360 degree angles for each shift of the reversing lever comprising an oscillatory crank actuating memher having formed thereon two rack segments, a connection from the reversing lever for rocking said member, a pair of pinions connected to rotate the crank, and manual control means for relatively moving said pinionsand member axially to engage the pinions alternatively with their I respective racks.

9. In a machine tool having a work support and a tool support adapted for relative to-andfro translatory movement and for relative cross feeding movement, reversing means including a member movable from one to the other of two alternative positions with each reversal of said translatory movement, the combination of a pick cross feed mechanism comprising a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of thecrank, driving connections from said member constructed and arranged and having alternative positions of adjustment to rotate the crank alternatively through approximate 180 degree and 360 degree angles with each movement of said member comprising a pair of toothed racks connected for movement with said member, a pair of pinions connected to rotate the crank, means to shift said pinions axially to engage the pinions selectively with their associated racks, and a locking device operable to permit axial movement of the pinions only for a predetermined angular position of the crank.

l0..In a machine tool having a work support and a tool support adapted for relative to-andfro translatory movement and for relative cross feeding movement, reversing means including a member movable from one to the other of two alternative positions with each reversal of said translatory movement, the combination of a pick cross feed mechanism comprising a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, driving connections from said member comprising a pair of toothed racks connected for movement with said member, a pair of pinions keyed to turn with the crank and shiftable axially to engage the pinions alternatively with their associated racks, said connectionsincluding the racks and associated pinions being constructed and proportioned to rotate the crank alternatively through approximate 180 degree and 360 degree angles with each movement of said member, a shifting element for said pinions, and a locking connectionbetween the crank and said shifting element arranged 9 normally to prevent movement of the shifting element and to permit such movement for one angular position only of the crank.

11. In a, machine tool having a work support and a tool support adapted for relative to-andfro translatory movement and for relative cross feeding movement, reversing means including a member movable from one to the other of two alternative positions with each reversal of said translatory movement, the combination of a pick cross feed mechanism comprising a, cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, driving connections from said member comprising a pair of toothed racks connected for movement with said memher, a pair of pinions keyed to turn with the crank and shiftable axially to engage the pinions alternatively with their associated racks, said connections including the racks and associated pinions being constructed and proportioned to rotate the crank alternatively through approximate 180 degrees and 360 degree angles with each movement of said member, a, pinion shifting element movable axially of the crank, and a locking disk secured to turn with the crank, said shifting element having transverse slots to receive the peripheral edge of said disk for each position of adjustment of the pinions, and said disk having in the peripheral edge thereof a, cutout to permit shifting of the shifting element for one angular position only of the disk.

12. In a machine tool having a work support and a tool support adapted for relative to-andfro translatory movement and for relative cross feeding movement, and reversing means including a, member movable from one to the other of two alternative positions with each reversal of said translatory movement, the combination of a pick cross feed mechanism comprising a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, driving connections from said member constructed and armovement with said member, a pair of pinions connected to rotate the crank, a manually operable control for shifting said pinions to engage one or the other of the pinions with its associated rack, and a removable cover enclosing said manual control, said cover and manual control being constructed and arranged to permit the closing of the cover only for positions of the manual control corresponding with a fully shifted position of said pinions.

13. In a machine tool having a work support and a tool support adapted for relative to-andfro translatory movement and for relative cross feeding movement, reversing means including a member movable from one to the other of two alternative positions with each reversal of said translatory movement, the combination of a pick cross feed mechanism comprising a cross feed ratchet, a pawl, a crank connected to impart a feed and recovery movement to the pawl for each full revolution of the crank, driving connections from said member constructed and arranged and having alternative positions of adjustment to rotatethe crank alternatively through approximate degree and 360 degree angles with each movement of said member comprising a pair of toothed racks movable with said member, a pair of pinions rotatable with the crank and shiftable axially for alternative engagement withsald racks, a manually operable shifting element for said pinions, a detent, and cooperating apertures in the shifting element within which the detent is seated for each position of adjustment of the pinions and shifting element, and a cover, said cover and detent being arranged to permit the closing of the cover only with the detent in seated position.

HANS C. WEIMAR.

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