US2364120A - Mechanism for grinding - Google Patents

Description

Dec. 5, 1944. M; H. ARMS MECHANISM FOR GRiNDING Filed Aug. 13, 1940 3 Sheets-Sheet 1 Dec. 5, 1944. M. H. ARMS 2,364,120

MECHANISM FOR GRINDING Filed Aug. 13, 1940 5 Sheets-Sheet 2 1a o Q Jf '7 D 9 4. M. H. Arms 2,364,120

MECHANISM FOR GRINDING 44 Filed Aug. 13; 1940 :5 Sheets-Sheet s Patenied Dec. 5, 1944 UNITED STATES PATENT ,IOFFI'CE MECHANISM FOR GRINDIN G Merton H. Arms, Springfield, Vt, assignor to Bryant Chncking Grinder Company, Springfield, Vt., a corporation of Vermont Application August 13, 1940, Serial No. 352,380

12 Claims.

This invention relates to the grinding of work and is particularly concerned with internal grind- One of the features of the invention relates to a multiple selective control of the feed of a grinding wheel spindle whereby the feed of the grinding wheel may be controlled selectively in accordance with a plurality of definite laws of action at difierent times, and if desired for operation on different portions of a piece of work.

One specific example of the use of such a control is found in grinding the bores of internal combustion engine cylinders particularly where the engine head is made of a relatively light weight alloy and has a threaded connection with the barrel portion. In'such work a very small departure from accurate cylindricity has been found desirable, particularly adjacent to the harrel ends. Such departures may also be found 'desirable at other portions. In accordance with this invention as applied to this type of work, the rough grinding may be cylindrical, the final grinding, only, providing for such departures from cylindricity.

An object of the present invention, therefore, is to provide a method and mechanism for effectmg such multiple feed control in a selective manner.

For a more complete understanding of thisinvention, reference may be had to the accompanying drawings in which Figure l is a front elevation of'a grinding machine embodying the invention as applied to the grinding of engine cylinder bores.

Figure 2 is a diagrammatic sectional view on line 2--2 of Figure 1, the departure from cylindrical of the work and the wheel being greatly exaggerated.

Figures 9 and 10 are views similar to Figures 7 and 8, respectively, but showing a modifledcoi'istruction and arrangement.

Figure 11 is a fragmentary longitudinal section V as showing much exaggerated the cylinder wall contour produced by the mechanism of Figures 9 and 10.

Figures 1 and 4 illustrate an internal grindingmachine of the well known Bryant type and as shown generally in the Arms Patent No. 2,176,985. It comprises a base I, a rotary work support 24 and a rockable and axially movable wheel carrier 3.

This wheel carrier is mounted for its rocking motion on an overhead axis of a cylindrical control bar 4 and the lower end of this carrier is provided'with an extension 5 which rests by gravity against a suitable feed control mechanism along which this extension rides during the axial traversing motion of the carrier 3. This carrier 3 3 supports a grinding wheel spindle 6 carrying a grinding wheel I at one end and a driving pulley 8 at the other. A driving belt 9 passes around the pulley 8 and about suitable idlers Ill and H, and about a drive pulley IQ of a motor I3.

As shown best in Figures 4 and 5, the extension 5 carries a pair of abutment members!!! and 2! at difierent radial distances from the axis oi. the

control bar 3, either of which may be employed;

as desired. The abutment member 20 is shown as a bar of circular cross section clamped in position by means of a clamping jaw 22 which may be secured in position as by bolts, one of which is shown as. at 23. The-abutment 2i is shown as a flat bar secured in adjusted position by screws such as it and adjustable substantially horizontally as by adjusting screws 25 provided with lock nuts rt. Both the abutments 2c and 2i extend for a substantial distance generally parallel to the member i so that they control the angular position of the wheel support 3 during the traverse of the grinding wheel along the interior of the work. Cooperating with the abutment 2B is a feed bar 30 which may carry a cam roller 3| at its rear end abutting the abutment 20. Similarly the abutment 2| may be engaged by a follower 32 Ma feed bar 33. The feed bar 30 may have a threaded shank portion 35 for engagement within a feed nut 36 journaled aga nst axial motion in asultable portion of the machine bed and the bar 33 may have a threaded extension 31 engaging in a nut 38 similarly held against axial motion. Suitable means may be provided for turning these nuts 36 and 38 as desired to move their respective. fe'ed bars axially. Thus the nut 36' may have keyed thereto ahand wheel 40 .provided with handles 4| thereon and for automatic feed it may have a ratchet ring .42 secured thereto for engagement by a feed ratchet which may, it desired, be carried by a re'ciprocatory bar 43 (Figure 1) actuated from within a casing 44. A memher 408 which may be rotated with the wheel40 or latched in stationary position may be provided with a micrometer feed pinion having an actuat-' ing handle 4|l| and it may extend over the ring 42 and act as apower feed limit stop when the member 408 is unlatched. The nut 38 may have I secured thereto a gear 45 which may be connected through an idler gear 46 with a gear 41 on a feed shaft 48. This shaft 48 may be provided with a hand wheel 48 similar to the hand wheel 48, and a ratchet mechanism micrometer hand feed, and feed limit stop similar to that applied to the nut 38.

In Figure a modification is'shown in which the lower feed abutment at 50 comprises a bar of circular cross section, while the'upper abutment 5| is formed as a fiat bar. A bar of circular cross section permits angular adjustment when worn to present a fresh guide surface. The fiat bar 5| may be found more convenient when there is considerable irregularity of contour. Either may be formed readily by a turning operation.

For internalcombustion engine cylinders of the type where the cylindrical barrel is secured to the head by a threaded connection, as illustrated in Figure 3, the barrel being shown at Siand the head at 56, in order to allow for expansion under normal working conditions of heat, it is found desirable to slightly enlarge the bore of the barrel inwardly from its head end and to have a reduced internal diameter at the extreme end. It is also found desirable to form the open end of the cylinder as at 51 with a slightly decreased 1 and 4, the barrel is supported ina suitable fixture 60 (Figure 2) by which it may be clamped in position with respect to'the work holder. 2,. and the grinding wheel I is caused to traverse it. Because of the very slight variation from true cylindrical contour desired in the finished barrel,

this invention provides for rough grinding the interior to cylindrical contour and then producing the slight departures from cylindrical contour at or adjacent to the ends of the barrel in the finish grinding, and preferably with the grinding wheel contour slightly modified from 5 the cylindrical contour desirable for-best results during ,the rough grinding.

A wheel truing diamond is illustrated at 65, this being positioned beyond the outer end of the work so that the wheel may be trued in an extended portion of its traverse where it is clear from the'work and in what may be termed the truing range of the wheel traverse as distinguished from the working range during which the wheel is in contact with the work. Assuming that the work is placed in the work holder for the rough grinding operation, the grinding wheel I, preferably trued to cylindrical contour, is caused to traverse the cylinder, the position of the wheel are shown very much exagger-.

- position of Figure 7 and traversed with a short with respect to the wall of the work being ad-" justed as desired through that one of the'feed mechanisms which is provided with the abutment arranged for producing a straight line traverser The wheel is fed into the work to the extent desired for the rough grinding operation by a suitable operation of the selected feed mechanism. For example, the machine may be equipped to operate as shown in-my Patent No. 2,176,985 previouslymentioned. If desired, the wheel may be trued cylindrical as often as desirable to preserve cylindrical contour and a good grinding face, through an extended traverse of the wheel, the traverse being linear and in line with the traverse within the work, the diamond 65 being moved into position for the truing operation in any suitable manner.

After the rough grinding has-been completed, the feed mechanism for the rough grinding is retracted and the feed mechanism for finish grinding brought into operation. It will be assumed'that this finish-grinding feed mechanism is that employing the abutment 20 of circular cross section, although as before stated, it might be the flat bar abutment if desired. The finish abutment, however, is not the same diameter throughout, but may be formed as shown in Figures 6, 7 and 8 with a cylindrical intermediate portion 10, a tapered portion 1|, and a smaller diameter cylindrical portion 12 adjacent thereto toward one end of the abutment. At the other side of the cylindrical portion 18 is an enlarged diameter portion 13 formed by a pair of tapered walls 14 and 15. Beyond this portion 13 is a smaller diameter portion It between tapered portions l1 and I8.

The wheel being retracted from the work into the position shown in Figure 8, and the feed mechanism including the follower roll 3| being in contact with the bar 20 at the'position shown in Figure 8, an outward traverse of the wheel carrier will bring the smaller diameter portion 16 to the follower and as the traverse away from the work continues, the grinding wheel will be trued to the contour shown in Figures 6, 7 and 8, having a central large diameter portion 88 and tapered to a smaller di'ameterat opposite ends as at 8|. The wheel being thus trued, traverse of the work is again commenced. Preferably the wheel is moved into the work and then fed thereagainst in the stroke, as by hand control, until the wheel'has been fed in sufficiently to engage theportion on a more extended traverse, at which time the normal power grinding traverse of full length is started and the finish grinding completed with the full traverse. The intermediate portion 85 is cylindrical and a reduced sloping portion 86 is ground adjacent to the open end of the barrel. Near to the opposite end of the barrel, there is ground an enlarged diameter portion 83 and at the end an inwardly sloping portion- 84. The follower roll 3| engages the enlarged diameter portion 13 of the abutment when working on the end of the cylinder barrel adjacent to the head and engages the portion II to form the taper contour adjacent to the open end of the cylinder. Thus the finish grinding operation produces the cylinder with its main portion truly cylindrical and its end portions having the slightly different but desired contours for the completed cylinder.

In Figures 9 and 10 is shown a modification in which the cylindrical rough grinding and modified finish grinding contours may be produced with a single grinding wheelfeed mechanism. In this case a pair of truing devices 90 and 9| are employed, one of these fortruing the wheel tocylindrical contour, and the other for truing it to a convex contour. The abutment 93 which 7 determines the angular position of'the wheel car- ' aso eiso rier, andthus the ,feed position of the wheel with relation to the work,'is provided with a cylin-r length. A portion of this cylindrical contour length as from a to b corresponds to the grind ing traverse of the work. Another portion of this cylindrical contourifrom a to c is for an extended traverse duringwhich the truing device when moved into operative position may true the wheel to cylindrical contour, this being the contour of the abutment between the portions a and c. This is the position shown in Figure 9. This abutment 93 has another portion between the points "d and e which is of decreased diameter. when the grinding wheel traverse is extended so that the follower 3'] engages this portion of the bar a, the wheel is so guided past the truing device 9|; which may be brought in operative relation to the grinding wheel, to true the grinding wheel to the convex contour illustrated in Figure 10 drical contour for the greater portionot its anisms for producing and controlling a teed mo-- tion of said shaft, each of said controlling mechanisms including a template for controlling such feed motions automatically in' accordance'with the traverse positions; of saidwheel and the contour of the controlling template, said templates having diite'rent' controlling contours, and means Y for selectively presenting one or another of said for the finish grinding operation. When the wheel of thiscontour is then applied for the finish grinding and the wheel traverse is limited to the distance a-b so that the wheel does not clear the work at either end, the resultant contour is that shownin Figure 11, where there is an intermediate central portion'of true cylindrical contour and tapered end portions 'at 95 and 98. The feed will then be retracted before the traverse is extended to remove the wheel from the work, so I that the finished wheel contour remains as shown in Figure 11. While this contour is not as desirable as that shown in Figures 2, 3, 6, 7 and 8, it may in-some cases serve the desiredpurpose.

While as shown, the departures from cylindrical contourtaper are in substantially straight lines, and the grinding wheel for finish grinding is similarly arranged, this is -not essential as the changes of contour may'be'aiong curved instead of straight lines if desired.

It will be noted that the various contours may be made on the same piece or work with a single chucking of the work so that these various contours are produced in definite accurate relation one to the other.

It should be evident to those skilled in the art that various other changes and modifications might bemade without departing from the spirit or scopeof this invention as defined by the appended claims.

I claim:

1. A grinding machine having a work support,

a grinding wheel shaft for suppor ing a grinding wheel, means for relatively reciprocating said whe'el shaft and work support to cause a grinding mechanisms in feed and controlling operative positions whereby each of said mechanisms may be rendered effective for the same work piece with a single chucking of said work piece.

3. In combination, means for supporting tubular work, a grinding wheel, two wheel truing devices, means for effecting a relative traverse of said wheel axially of the work to cause said wheel to grind thev inside of said work, means for con trolling one of said truing devices 'at one time during an extended portion of such traverse to true said wheel to cylindrical contour, means for controlling the other of said truing devices and wheel at another time during such extended trav- I erse portion to true said wheel to a convex contour, means for controlling the path of grinding traverse while said wheel is of cylindrical con-.1

tour to effect a roughing cylindrical grinding cut, and means for controlling the path of grinding traverse, while said wheel is of convex conwheel on said shift to traverse work on said support, a plurality of mechanisms for producing and controlling relative and support, each of including a templet for controlling said feed motions automatically in accordance with the relative traverse positions v and the contour of the controlling template, said templates having and means forselectively presenting meet another mechanism in operative feed and controlling position whereby may be rendered efiective forrthe same work piece each of said mechanisms with a single chucking of said work piece.'

2. A grindingmachine having a work support, a grinding wheel shaft for supporting a grinding wheel, means for'reciprocating said wheel shaft jtctraversea' grinding wheel carried by said shaft along work on said support, a plurality of mechof said wheel and the work different controlling contours,

tour to effects finishing grinding cut departingfrom cylindrical at a portion of the work and while the work remains in the same relation to said work supporting means as during the roughing cut. i

4. In a grinding machine having a rotary work support, an axially movable wheel support rockable about an axis spaced from the axis of rotation of workon said work support, a grindingwheel carried by said support, meansfor rem rocating said wheel support axially to cause said wheel to traverse work carried by said work support, a pair of means selectively operable to control the angular position of said wheel support as said wheel support is reciprocated, the means oi said' pair being set for different controls, and

a wheel truing device,-and a means corresponding to each'ot said pair of means for causing said truing deviceto true the wheel to a contour, each different from the other and corresponding to such selection, whereby the work may be ground first to one contour by the wheel trued to one contour and then to a diil'erent contour by the wheel trued to a diflerent contour while the work remains in the same relationship to said work supporting means.

5. In a'grindingmachine having a rotary work I support, an axially movable wheel support rockable about an axis spaced from the axis of rotation ,of work on said work support, 'a grinding feed motions of said shaft said controlling mechanisms vices positioned at operative on the; same work piece at wheel carried by said support,-means for reciprocating said wheel support axially to cause said work in prising a carrier for a rotary work support and work support, means for relatively reciprocating said holder and wheel carriage substantially parallel to said axis, a plurality of templates carried by one of said members and a follower for each template carried by the other of said members for traverse of its respective template during such reciprocation and controlling'the transverse position of said carriage during such reciprocation,

- Y a grinding wheel carriage mounted for relative motion transverse to the axis of rotation of said and for feeding and retracting motions on swing ing of said arm, a plurality .of pairs of cooperatin'g members, one member of each'pair being a and means for independently adjusting said iollowers with respect to their respective templates to bring any selected one of saidfollowers into operative relation to its template while the others are inoperative, whereby a work piece may be subjected to grinding operations controlled by a plurality of said templets during a single chucking. 1

'I. A grinding machine having members comprising a holder for a rotary work support anda grinding wheel carriage mounted for relative motion transverse to the axis of rotation of said work support, a grinding wheel mounted on said carriage, means for reciprocating said holder substantially parallel to said axis throughout a justing said followers with respect totheir respective templates to bring any one selected follower into operative relation to its template .while the others are inoperative, whereby a work piece may be subjected to grinding operations controlled by a pluralityof said templets during a single chucking. I

8. In a grinding machine, a bed, a rotary work support carried by said bed, anarm mounted on template and the other of. said members being a follower for traversing said template, one of the members of each pair being carried by said arm and the other of said members being carried by said bed, said arm-carrying members being located at ditjterent distances from said am axis, and means-for adjusting the bed-carried member of each pair into and out of cooperative relation to its cooperating member, whereby any selected one of said pairs of members may be made effective to control the angular position of said arm in accordance with the axial pomtion thereof as determined by the contour of its respective template and a plurality of said pairs of members may-be sequentially effective on a work piece during a single chucking .of a work piece.

10. In combination,

said workaholder within a working range and outside of said working range in awheel truin range, a plurality of wheel truing tools located at difierent axial portions of said truing range,

means. including templates and followers for traversing said templates as the wheel .traverses, determining the position of said wheel transverse to its traverse during such traverse, and means for rendering any selected one of said truing tools operative to true the wheel to a contour said bed for pivotal and axial motion with respect to the pivotal axis, a grinding wheelcarried by -said arm for traversing work carried by said work support on axial motion of said arm and for .feeding'and retracting motions on swinging of said arm, a plurality of pairs of cooperating members, one member of each pair being a template and the other of said members being a follower for traversing said template, one of the members of each pair being carried by said arm and the otherof said members being carried by said bed, and means for adjusting the bed-carried member of each pair into and out of cooperative relation to its cooperating member, whereby any selected one of said pairs of members may be made effective to control the angular position of said arm in accordance with the axial position thereof as determined by the contour of its respective template and a plurality of said pairs of members may be sequentially effective on a work piece during a single chucking of a work piece.

9., In a grinding machine, a bed, a rotary work determined by the contour of the portion of the template controlling the transverse position of said wheel in that portion ofthe truing range within which the selected truing tool is positioned, whereby a. work piece may be subjected" to grinding operations controlled by a plurality of said templets during a single chucking.

11. In' combination, means for supporting work, a grinding wheel carriage, means for rotarily supporting .a grinding wheel on said car- 7 riage at a selected'axial position, means foreffecting a )raverse of said carriage relative to said work support within a working range wherein said wheelmay operate on work carried by said supporting means and beyond said working range in one direction in a wheel truing range, a plurality of wheel truing devices located at different axial portions of said truing range, means ineluding a template and a follower for traversing said template as the carriage traverses for controlling the transverse position of said carriage,

and means for rendering any selected one of said devices operative to true the wheel to a contour determined by the contour of the portion of the template controlling the transverse position of the carriage in'that portion of the truing range during which the grinding wheel is in effective axial relation to the selected truing device,

whereby a work piece may be subjected to grinding operations controlled by a plurality of said templets during asingle chucking.

12. In combination, means for supporting tu-" bular work, grinding mechanism including an internal grinding wheel, wheel truing means positioned to act on said grinding wheel/when said grinding means is retracted axially relative to support carried by said bed, an arm mounted on 7 said bed for pivotal and axial motion with rethe work, means for producing relative motion of said work and wheel axially, and a plurality of mechanisms selectively operable tocontrol the position of said wheel transverse to the work axis, each of the controlling means including a former cam and a 'follower'for traversing its respective former cam, each of said former camshaving a means for supporting work, a grinding wheel, means for eflecting a traverse of said wheel relative to work carried by I lengthwise" portion 'for controlling the position of said wheel while in grinding relation to the work,

and a lengthwise portion for controlling the position of said wheel while said wheel is in operative relation to truing means, said portions of one of 5 contour.

said former cams being contoured to produce cylindrical-grinding of the work and cylindrical MER'I'ON H. ARMS.

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