US2365059A - Feed mechanism for grinding machines - Google Patents

Description

Dec. 12, 1944. J DECKER 2,365,059

FEED MECHANISM FOR GRINDING MACHINES Filed June 26, 1942 s Shets-Sheet 1 Dec. 12, 1944. J. DECKER 2,365,059

FEED MECHANISM FOR GRINDING MACHINES Filed June 26, 1942 5 Sheets-Sheet 2 3 INVENTOR.

' JYCQBD Fafm lid 6' BY Dec. 12, 1944. J. DECKER 2,365,059

FEED MECHANISM FOR GRINDING MA CHINES Filed June 26, 1942 3 Sheets-Sheet 3 I22?! 4 I N VE NTOR. l/T coa DfCY/f/P Patented Dec. 12, 1944 FEED MECHANISM FOR GRINDING MACHINES Jacob Decker, Cincinnati, Ohio, assignor to The Cincinnati Milling Machine 00., Cincinnati, Ohio, a corporation of Ohio Application June 26, 1942, Serial No. 448,559 1401m (01. 51165) vide improved means for precisely indicating the relative relation of the grinding wheel with respect to the work so as to facilitate the sizing of the work.

Another object of this invention is to provide improved stop means for limiting the cross feed movement regardless of whether it is effected manually or by power, and to associate therewith a graduated dial means to indicate the movement necessary to reach said stop means and which will always have a zero reading when the stop has been reached.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described within the scope of the appended claims, without departing from or exceeding the spirit of the invention. Y

Referring to the drawings in which like referehce numerals indicate like or similar parts:

Figure 1 is an elevation of a machinetool embodying the principles of this invention.

Figure 2 is a section on the line 2-2 of Figure 1.

Figure 3 is a section on the line 33 of Figure 2, showing the dial locking means.

Figure 4 is a section on the line 4-4 of Figure 2, showing the positive stop means. V

Figure 5 is a section on the line 5-5 of Figure 4, showing a cross section through the pick feed mechanism.

Figure 6 is a section on the line 66 of Figure 4.

Figure 7 is a detail view of a portion of the graduated dial means as viewed on the line 'I--'I of Figure 3.

Figure 8 is a detail view of means for connecting the mechanism of this invention to a wheel slide.

This invention is particularly adaptable for effecting relative approach and retractive movements between a grinding wheel and a work support, which movements are known in the art as cross feeding movements. t

In Figure 1 of the drawings isan exemplification of a grinding machine to which this invention is particularly adaptable and which will serve to illustrate the principles and advantages thereof.

In this machine there is a work support I0 and a grinding wheel support I I,'the latter having a grinding wheel I2 rotatably mounted thereon. These supports are mounted on a bed I3 for relative movement and in this instance the work support may be traversed parallel to the axis of the grinding wheel for traverse grinding, while the wheel support may be crossfed toward the work support for grinding and sizing purposes. It will be understood, however, that this invention is equally applicable to machines in which the other arrangement prevails, i. e., that the work support is adjustable toward and from the grinding wheel support.

Referring to Figure 2 a drive gear I4, forming the output member of the mechanism of this in-. vention, is connected by a suitable motion transmitting train to the cross slide which in this case is the grinding wheel support I I. This train may be of any suitable construction such as that, shown in Figures 2 and 8. The gear I4 drives a gear I5 through an intermediate idler gear H3. The gear I5 is attached to the end of a shaft I! which, as shown in Figure 8, terminates in a worm I8. The worm meshes with a worm gear I9 that has an integral pinion 20 which meshes with a rack 2|. The rack 2| is connected to the cross slide I I whereby itwill be evident that upon rotation of the gear I4 the worm will be rotated. thus driving the pinion 20 which will transform rotary motion into reciprocating motion of the cross slide.

This invention is directed more particularly to means for advancing the gear I4 in very small increments for precision grinding purposes, or at a fast rate for major adjustment and set-up purposes. To this end the drive gear I4 is attached to the end of a sleeve 22 which is journaled at 23 and 24 in a fixed part 25 of the machine. The sleeve terminates in an internal-gear 26. A shaft 21 extends through the bore of the sleeve and is jcurnaled at opposite ends in bushings 28 and 29' for rotation independently of the sleeve. The shaft 2'! has an integral eccentric portion 30 and a concentric portion 3!.

A second :internal gear 32 is supported by antifriction bearings 33 on the concentric portion 3| for independent rotation relative to the shaft. A hand wheel 34 is keyed at 35 to the shaft 3| for effecting rotation of the eccentric portion 30 relative to the sleeve, it being understood that the sleeve in such a case would be held against attached to the face thereof as by screws; 41! and this plate has a series of notches 4! cut in the periphery thereof for engagement by the end 42' of a spring pressed plunger 43 which is positively connected to a handle 44 carried by. the hand wheel 34.

The notches are ten in; number as shown in F re 3' which means that the distance between each-notch corresponds to one-thousandth of a revolution of the internal gear 32. The handle 44 is telescopingly slidably mounted on a tubular member 45-which is fixedto thehand wheel and projects-therefrom in adirection parallel to its axis of rotation. A spring 46 is interposed between the-fixed member 45 and the plunger 43 for oentinuallyurging it in a direction toward the notched plate; It will be obvious that the end 42 1 mustfi-tthe slots withoutlostmotion ifprecision grinding results are to be obtained.

sipgetheplate 39 is integrallyconnected to the internal'gear- 32 it'will be obvious that when the p ums; 42 i nnsfl e sn th. th plate that the hand wheel 34, the internal gear 32, the shaft 3|, the gears 36 and 3], and the internal gear 26 are connected for joint rotation. In other ord a of; hese. pa ts wi o a e. as a it. hcr br enarotatia Q t emed Wh e ll af t one. otat on f h gea A graduated. dial in the form of a ring 41 sure rounds. the internal gear 32 and, is connectible h reto by emean own in Fi r This me ns vcmprisesa locking member 48. wh h is pivctal lt p or fid on Din49. wh carried, by, the, dial 4.1-. and therefore movable herewi h h lo ki member. 46-. is provided on one. end. with a serie of notchesor teeth 50, which are adapted to be pressed into engagement withthe toothd peripheryi 5 I of the. internal gear- 33, The locking member is; somewhat semi-ciru s n. Shap hdat the oth r nd aspr 'ng is; interposed between theclamping. member. 48 and the interior of the dial ring 41 which tends te urge the locking member out of engagement withthe internal gear. A clamping'screw 53 is ra ially threadedin the dial for ngagement with the' tch d. d hinelamp n m m c r l ing; the; same intoengagemcnt'with; the teeth 5;! whereby thedial is cl mped forrotary movement w h the. nte al-s ar 1 The dial 4'! is provided with graduation marks generally indicated bythe reference numeral 54, Eigure 7; and these graduation marks extend completely around the periphery of the dial and are spaced apart: equal distances, each graduation mark being equivalent tov .0005?" infeed or .001" as respects the diameter of thework. The

graduation marks are numbered counterclockwise around the dial beginning with a zero mark which is indicated by the reference numeral 55. A cooperating zero mark 56 is placed on a fixed part of the machine. It will now be apparent that upon counterclockwise rotation of the hand wheel which is the direct on for. effecting infeed, that the dial reading will progressively decrease until the zero marks 55 and 56 register.

This is the arrangement utilized for effecting actual rotation of gear I4 and bodily movement of: the cross slide. When the pin or plunger 44 is withdrawn and the hand wheel rotated, a different effect, is produced. There is no bodily movement of the. slide this time but, instead, the

gean- M; isheld stationary by the friction of the slide and the gear 32 becomes the driven member. The purpose of'this will become apparent as the description progresses.

Thechief reason for any grinding operation is to size a work piece with precision'andin order to facilitate this in production grinding a positive stop meansis provided comprising; a positivestop 51 which is slidably mounted infa fixed part of the machine. The dial 41 carries a stop plate 58 attached to one face ofit asby screws 59 as shown in Figures 2 and4. The stop plateis attached to the dial in such relation that when the plate is in engagement with the-positive stop 5] the zero.

graduations 55 and 56 are in registry.

Although a p e. to pr ided. nd may serveto size several work pieces in succession it must be remembered that the grinding Wheel is continuously Wearing away, even although at a.

very slow rate and therefore adjustments must a1 movement of the feeding mechanismso that, the periphery of the wheel may be brou ht, to the same position, The amountof adjustment to be made has to be determined, by. the operator by,

comparing the actual size of the. workpiece with.

the. desired size. The amount of this difference will vary but for wheel compensating purposes.-

it will be very small and thatis why theiprecision adjusting mechanism for the. dial is provided,

whereby the dial may be rotated as small an amount as .0001" a respects work diameter. In other words, by withdrawing the pin, and rotating the hand wheel 34 the dial 4! is moved independently oftherest of the mechanism, i. e.,

with respect to the drive gear l4 to move. the stop;

plate 58, a, predetermined distance equalto the the positive stop 51. The stop, plate 58- is moved in a clockwise direction as viewed in Figure 4 whereby after the hand-wheel is locked again to the plate 39 the gear [4 may be rotated an additional amountinacounterclockwise direction until the stops engage, thus moving the wheel an additional precision amount-toward the work.

After the workpiece has been ground the wheel 34 is rotated in a clockwise direction to effect retraction o f't he; grinding wheel. If the hand wheel is rotated in a clockwise direction more than, one revolution, it will" be obvious-that the stop plate would collide with the positive stop. Means are provided whereby the positive stop may be withdrawn manuallyby the operator,

or automatically withdrawn by rotation of the wheel should the operator forget. The automatic withdrawal is eifected by providing a beveled surface 60 on the stop 51 and a beveled surface 6| on. the stop. plate 58 so that when these surfaces collide, the stop 51 is moved by a Wedging action out of the path of the stop plate.

The stop 51 is slidably mounted in a bore GI and is provided with a pair of V-notches' 62 and 63 which are alternately engaged by a spring pressed detent ball 64. A limit pin 65 is secured in a fixed part of the machine and projects into an elongated slot 66 in the stop to limit the movement of the stop in either direction. The stop is moved manually by a lever 61, Figure 6, which has a ball-shaped end 68 fitting in a socket 69 formed in a fixed plate 10. The intermediate portion H of the lever passes through a bore 12 formed in the enlarged head '13 formed on the end of the stop 51. The lever is supported by a pin 14 which passes through the head 13 and the reduced portion ll of the lever, while the lower end is anchored in the bore 69, whereby when the handle is oscillated it will move the stop 51 in one direction or the other.

For traverse grinding operations in which it is the usual practice to feed the grinding wheel toward the work a predetermined amount at each reversal of the worktable, a pick feed mechanism has been provided which is totally enclosed so as tQ eliminate exposed moving parts.

The pick feed mechanism comprises a power reciprocable piston which. is adapted to be operativel connected to a table reversing mechanism in such manner that the piston will effect a complete reciprocation each time the table is reversed. The manner of connecting this piston forms no part of the present invention. The piston which is indicated by the reference numeral is provided with rack teeth 16 which intermesh with gear teeth ll formed integral with a lever 18, Figures 4 and 5, which carries a pair pawls l9. Springs 8!! urge the pawls into engagement with a ratchet wheel 8! which is integrally connected to a pinion 82 thatmeshes with a gear 83.

bearings 84.

Although the gear wheel 83 drives the sleeve 22 it is not directly connected to it, but rather is connected through the dial 4'! and the differential gearing to the sleeve. This is because the gear wheel carries means for automatically stopping the pick feed piston when the stop members 51 and 53 engage and since it is necessary that this be timed with zero reading ofthe dial, it is necessary that the gear wheel 83 always be in step with the dial, whether operating power comes from the pick feed piston, or from manual rotation of the eccentric at which time the sleeve is stationary. I

The automatic stop-ping of the pick feed is accomplished by providing a stop valve 85 which is mounted in the housing parallel to the shaft 3! and this valve has a plunger 86 upon the end of which is formed a contact button 8'! which is adapted to be engaged by a stop button 88 carried by the gear 83. Since the gear 33 is mounted for free rotation on the sleeve 22 it is necessary to provide a driving connection between the gear 83 and the sleeve and still make it possible for the stop button 38 to be adjusted independently of the sleeve so as to arrange for automatic stopping of the wheel head in any position. This connection is, therefore, made through the dial to the sleeve and to this end the button 38 has a reduced elongated shank 89 by which it 'is mounted in the gear and which projects beyond .the opposite face thereof a sufficient distance to engage a slot 90 formed in the back face of stop plate 58. Thus, the gear 83, the stop plate 58"and the dial 4'! arepositivel connected together at all times for joint rotation.

It is, therefore, possible to position the stop button 88 circumferentiall on the gear 83 in such position that the stop button 88 will engage and shift the valve plunger 86 at the same moment that the stop plate 58 engages the positive stop 51.

The valve 85 is serially connected in a control line for the pick feed piston, comprising branches 9| and 92. The branch 9i leads to one end of cylinder 93 and the other branch 92 to a control source whereby in one position the line 92 is connected to the line 9i, and in the other position the branch BI is connected to exhaust line 94. The valve is provided with a hydraulic detent comprising a pressure port 95 which is positioned adjacent an enlarged spool 96 formed on the valve. plunger 85 to provide a differential area with respect to the adjacent spools 91 and 98 whereby after the plunger passes through a midposition the hydraulic pressure will enter the opposite side of the spool 96 and complete the shifting movement.

The valve plunger 36 is reset to the position .shown in Figure 2 by connecting fluid pressure The gear 33 is supported for free rotation on the sleeve 22 by anti-friction through the medium of a manually operable pilot valve I06 to port Hill of valve 85. The pilot valve has a plunger llll which is spring held in the position shown. Upon manual operation by depressing knob Hlt, port IE9 is connected to pressure port I it] and upon return of the plunger port I09 is connected to exhaust port i l i. The valve is mounted on the front of the machine near the hand Wheel 34 as shown in Figure 1 and thus is readily accessible to the operator.

Attention is invited to the fact that the arm 18 is normally in its return position and that the pawls 19 are provided with heels 99 that engage a stop Iii-Ii to move the pawls out of engagement with the ratchet wheel whereby any rotation by the hand wheel 34 which would cause rotation of the gear 83 will not be interfered with because of engagement of the pawl with the ratchet wheel.

Another manner of preventing interference by the ratchet teeth is to slidably mount the gear 82 on its supporting shaft IN, the shaft having a spline Hi2 which interconnects the ratchet wheel 8| with the gear 82. By sliding the gear 82 to the. left as viewed in Figure 5, it may be disconnected from the gear 83. The disconnection may be effected by a gear shift control lever I03 mounted on the front of the machine as shown in Figure 1. A spring pressed ball detent I04 is utilized for holding the gear in either one of its two positions.

It will be noted that double pawls 79 are provided and that one is set slightly ahead of the other a distance equal to one-half of the circumferential pitch of the teeth on wheel 8!, and this is for the purpose of attaining a finer ad'- justment and pickup.

The entire pickfeed mechanism is enclosed within a housing I05 as shown in Figure 2 which the operator.

which may be. alternatively. rotated by; either hand or power means; stop means for determining a limit to the rotation and thereby a final size. of the Work; graduated means for indicating the prospective amout of stock to be. removed before the stops engage; and means; for micro,- metrically resetting the stops independent of the actuator to permit additional movement of the actuator should the final size of the work as first determined by the stops prove to be too large.

It is important to note that in the operation of a grinding machine it is the customary practice to provide some form of positive stop meansand' then to feed against that stop so that repetitive grinding operations may be-performed without requiring a lot of attention on the part. of Itis always of interest. to theoperatorin. setting-up a machine and after bring-.

ing the grinding wheel into engagement with the periphery of a work diameter to be able to.

so graduated that the operator may read directly'the amount of reduction in work diameter that will be effected for an given angular movementof the infeeding mechanism, it being understood that the grinding wheel is in contact with theperiphery of the work at. the time the feeding movement starts.

It is alsov customary or desirable in the operation of grinding machines to have the operating handle such as the handle 44 in substantially the circumferential position that itis in in Figure 1 at the time that the grinding operation is, completed because in this position it is more convenient to start the clockwise rotation of the handwheel when retraction of the grinding Wheel has to be effected. To permit this to be obtained without disturbing the setting of all the other parts the locking screw 53 may be. backed off and the dial ring 4! held against the positive stop as by the screw 53 and then the handle 44 withdrawn from engagement with the slots 41 and the hand wheel 34 rotated to bringthe handle 44 to the desired position. This movement will neither cause actuation of the gear I4 nor rotation of the dial 4'! whereby all of the essential operating parts remain in their same position with the exception that the handle 44 is, relocated'to a more convenient position forrepetitive grinding operations.

What is claimed is:

1. In a grinding machine having a fixed support, and a grinding wheel head reciprocablymounted on said fixed support, the combination of means for feeding said wheel head including a rotatable member mounted in said fixed sup.- port and operatively connected for transmitting motion to said wheel head upon rotation of the member, a graduated dial surrounding said member, means for operatively connecting said dial to the member for rotation therewith, a gear fixed with said member, a fluid operable; pick feed mechanism operatively connected for transmitting intermittent movements to said gear, a stop valve for controlling operation of said pick feed mechanism, fiuid operable means for holding said valve in a running position, cooperating zero marks carried by the dial and the fixed support, and means carried by the gear for shifting said stop valve-to a stop position when said zero marks are in register.

2. In a grinding machine having a bed, a work That. is: why the dial means involved in this invention is.

supportv and; a, grinding wheel: support momma-.-

bly mounted on said bed, one of which is capable of movement toward: and from the other, the combination of means for effecting" said move,-

, ment including a rotatable, shaft, a power 0p,-

parting m vem t, to th ri di gv h el, a gear: attached to said member, a poweroperable pick;

feed mechanism for imparting intermittent, movement to said gear, and a shif-table gear for selectively connecting, or disconnecting said automaticpickfeed mechanism, to or from said first-l named gear.

4. In a grinding; machine havinga reciprocating work table and. a grinding wheel support oar.- rying a rotatable grinding wheel, the combination of means for reciprocating said table" including an automatic reversing mechanism, a power, operable pickfeed mechanism for feeding said grinding wheel support, means permanently connecting said pick feed mechanism with said reversing mechanism whereby said pick, feed, mechanism will be actuated upon each reversal of the table, means to selectivelyv connect saidpick feed mechanism to the grinding wheel support for intermittent actuation thereof, a stopv control for said pick feed mechanism, and means operable by said pick feed mechanism for effecting trip actuation of said stop control.

5. In a pick feed mechanism for the grinding; wheel support of a grinding machine, the combination of a fluid oscillated piston, ratchet means operatively connecting said piston for imparting an increment of movement to said wheel head upon each reciprocation of said piston,

.of a grinding machine, the combination of anactuator having motion transmitting connections With said wheel head, a fixed stop, a movable stop, selective means for connecting the movable stop for simultaneous movement with the actuator and toward the positive stop to determine the limit of feeding movement by said actuator, or for adjusting said movable stop relative to said actuator and away from said positive stop tov permit additional movement of the actuator, a graduated indicator operatively connected forjoint movement with said movable stop, said indicator being graduated in terms of work diameter reduction whereby the movable stop may beset in accordance with the reduction in work diameter to be effected by said actuator.

7. In a feeding mechanism for the Wheel head of a grinding machine, thecombination of a hand wheel for operating said mechanism, a positive stop, an adjustably positionable stop, means to operatively connect the adjustable stop to the;

hand wheel for limitingrotation thereof in a feeding direction by engaging the positivestop, means to adjust the movable stop after engagement with the positive stop relative to the hand wheel and in a direction away from-the positive stop, and a graduated scale movable with the movable stop having graduations indicating reduction in work diameter that will be effected upon return movement of the movable stop with the hand wheel into engagement with the positive stop.

8. In a feeding mechanism for the wheel head of a grinding machine, the combination of a fixed stop, an adjustable stop, a hand wheel for operating said mechanism, means'to utilize the hand wheel to effect relative spacing adjustment between said'stops without actuation of said mechanism to vary or determine the potential'movement of said mechanism, a graduated indicator integral with the adjustable stop to indicate the work diameter reduction efiectable by said potential movement, and means to connect the movable stop and the hand wheel directly to said mechanism for joint actuation in a direction to effect said reduction. p

9. In a feeding mechanism for the wheel head of a grinding machine, the combination of a hand wheel for actuating said mechanism, means to connect the hand wheel direct to said mechanism, a pair of stop members for limiting said actuation, one of which is fixed and the other movable with said mechanism, means to disconnect the hand wheel from said mechanism, reduction gearing rendered effective upon said disconnection for connecting the hand wheel for micrometrical adjustment of said movable stop.

10. In a feeding mechanism for a grinding machine, the combination of an intermittently operable pick feed gear, a graduated ring dial and a hand wheel supported in coaxial relationship and connected together for joint rotation, a final drive gear, means operatively connecting the dial to the drive gear, a positive stop, and a cooperating stop carried by the dial to limit rotation of the drive gear regardless of whether the rotation is effected by the hand wheel or the pick feed gear.

11. In a feeding mechanism for a grinding machine, the comblnationof an intermittently operable pick feed gear, a final drivegear, a graduated ring dial and a hand wheel all mounted in c0- axial relationship, means connecting all of the parts together for joint rotation, a fixed reference mark, graduations on the dial including a zero mark movable with respect to said reference mark, a positive stop, and a cooperating stop carried by the dial to limit rotation of the drive gear regardless of whether the rotation is effected by the hand wheel or the pick feed gear, said graduations being so positioned that the zero mark willregister with the reference mark when said stops are in engagement.

12. In a feeding-mechanism for a grinding machine, the combination of a final drive gear, an intermittently operable pick feed gear, a graduated ring dial and a hand wheel all supported in coaxial relationship and connected together for joint rotation, power operable means for intermittently actuating said pick feed gear including a start and stop control member, a positive stop, a cooperating stop carried by the dial, a trip member for said stop control carried by said dial, said trip member and said stop member being so positioned on the dial that they will engage the respective elements simultaneously.

13. In a feedingmechanism for a grinding machine, the combination of a final drive gear, an intermittently operable pick feed, a graduated dial ring, and a hand wheel all supported in 00- axial relationship and connected together for joint rotation, a fixed reference mark, graduations on the dial including a zero mark movable with the dial with respect to said reference mark, power operable means for intermittently actuating said pick feed gear including a start and stop control member, a positive stop, a cooperating stop carried by the dial, a trip member for said control member also carried by said dial, said trip member, cooperating stop and zero mark being so positioned on the dial that the zero mark will move into registry with the reference mark when said trip member and cooperating stop engage respectively the stop control member and the positive stop.

14. In a feeding mechanism for the wheelhead of a grinding machine, the combination with a support, of a sleeve rotatably mounted therein having gears on opposite ends thereof, means operatively connecting one of said gears to the wheelhead, a shaft rotatably mounted in the sleeve and having a portion projecting beyond one end thereof, said projecting portion comprising an eccentric portion and a concentric portion, a dial rotatably mounted on the concentric portion and 1 having a gear formed on one end thereof, a gear couplet mounted on said eccentric portion and interengaging gears on said sleeve and dial, a handwheel keyed to the shaft, a fixed stop mounted in the housing, a cooperating stop carried by the dial, a locking pin carried by the handwheel for interengagement with the dial whereby when the pin is engaged all of the parts rotate in unison and movement of the wheelhead is effected and when said pin is disengaged rotation of the dial is effected and the wheelhead remains stationary.

, JACOB DECKER.

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