US3034268A - Grinding machine - Google Patents

Description

May 15, 1962 s. H. SMITH GRINDING MACHINE 2 Sheets-Sheet 1 Filed May 3, 1960 3 TE PHEN 4521 l A TTO y 1962 s. H. SMITH 3,034,268

GRINDING MACHINE Filed May 3, 1960 2 Sheets-Sheet 2 NVEN'TOR. H j] 67 5/ STEPHEN SMITH United States The invention relates to grinding machines and more particularly to a crankpin grinding machine particularly suited to grinding the crankpins on a crankshaft so arranged that the various crankpins do not all lie in a common plane, and especially to such grinding machines particularly suited to use with automatic loading apparatus.

While the prior art includes various teachings of arrangements for supporting crankshafts for grinding various crankpins thereon and for properly angularly positioning such crankshafts for grinding the desired crankpins, the arrangements illustrated in the prior art teachings are not well suited to use with automatic loading apparatus arranged to deposit and remove crankshafts to be ground by movement along a given predetermined path irrespective of the particular crankpin to be ground.

The instant invention contemplates an arrangement whereby crankshafts deposited in a grinding machine of the type illustrated in Mader patent, No. 2,723,503, issued November 15, 1955, by means of a work loading mechanism of the type illustrated in Narel et al. patent, No. 2,813,380, issued November 19, 1957, may be precisely positioned angularly as they are deposited for grinding the respective crankpins located between the craukpins adjacent to the respective ends of the crankshaft.

An object of the present invention is the provision of an angular work locator assembly associated with the respective pot chucks of a grinding machine arranged to precisely position a crankshaft in a predetermined angular position for grinding a given intermediate crankpin thereon.

Another object is to provide an angular work locator assembly including first and second portions respectively secured to opposed pot chucks on a grinding machine respectively arranged to engage opposed portions of a crankshaft to precisely position and fully constrain a crankshaft in a predetermined angular orientation.

A further object is the provision of an angular Work locator assembly including first and second portions arranged to be selectively secured to the respective pot chucks of a grinding machine in predetermined coordinated positions so as to precisely angularly position a given crankshaft in one of several predetermined angular orientations for grinding different crankpins intermediate the ends of a given crankshaft.

Other objects and advantages of the instant invention will become apparent upon consideration of the following descripdon in relation to the showing in the drawings wherein:

PEG. 1 is a right hand end illustration of the left hand pot chuck of a grinding machine with the pot chuck and the pcrL cn of the angular locator attached thereto positioned for grinding the No. 2 pin of a crankshaft,

FIG. 2 is a left hand end illustration of the right hand pot chuck on a grinding machine and the portion of the angular locator attached thereto positioned for grinding No. 2 pin,

PEG. 3 is a right hand end illustration of the left hand pot chuck of a grinding machine with the pot chuck and the portion of the angular locator attached thereto posi tioned for grinding the No. 5 pin of a crankshaft,

FIG. 4 is a left hand end illustration of the right hand po't chuck on a grinding machine and the portion of the atent pot chuck of a grinding machine with the pot chuck and the portion of the angular locator attached thereto positioned for grinding No. 3 pin on a crankshaft,

PEG. 6 is a left hand end illustration of the right hand pot chuck on a grinding machine and the portionof the angular l'ocator attached thereto positioned for grinding No. 3 pin on a crankshaft,

FIG. 7 is a right hand end illustration of the left hand pot chuck of a grinding machine with the pot chuck and the portion of the angular l'ocator attached theretopositioned for grinding No. 4 pinon a crankshaft,

FIG. 8 is a left hand end illustration of the right hand pot chuck on a grinding machine and the portion of the angular loeator attached thereto positioned for grinding No. 4 pin on a crankshaft,

FIG. 9 is a fragmentary front elevation, on a reduced scale, of a crankpin grinding machine incorporating the preferred embodiment of the instant invention,

FIG. 10 is an enlarged side elevation of the fixedly mounted portion of the angular locator illustrating details of .e adjustable mounting means for this portion of the angular locator, and I PEG. 11 is a vertical section taken substantially on line 11--11 of FIG. 10 and also including a typical section through the adjoining portion of one of the mounting rings. 7

Referring now to the drawings wherein like reference numerals are used to identify like or corresponding parts 'in each of the several views, FIG. 9 illustrates a portion of a grinding machine incorporating theinstant invention comprising a base or work table It) which supports a pair of spaced aligned work heads 11 and 12 in turn supporting a pair of axially aligned rotatable work spindies 13 and M, respectively. The opposing ends of the spindles 13 and 14 are provided with face plates 15 and 16, respectively, which support a pair of work supporting pot chucks i7 and 18 arranged to engage and support portions of a crankshaft 21 to be ground disposed adjacent the opposite ends of the crankshaft 2i and concentric to its axis of rotation. Such portions may, for example, comprise crankshaft main bearings.

. The respective work heads H and 12 enclose elements of a driving mechanism not illustrated, interconnected by a drive shaft 22 and sleeves 23 and 24 and arranged to provide synchronous rotation of the respective work spindles 13 and 14. This driving mechanism may conveniently comprise an arrangement such as that best illustrated in FIG. 3 of Mader patent, No. 2,723,503, or any other suitable arrangement for this purpose. This driving mechanism is not illustrated or described in detail, since this driving mechanism does not constitute a portion of the instant invention. However, it is to be understood that such a driving mechanism is operable during the grinding operation to rotate the pot chucks 17 and 18 synchronously to rotate the crankshaft 21 about the axis'of the crankpin to be ground.

A transversely movable rotatable grinding wheel 3%) is The respective pot chucks 17 and 18 may convenientlywhich it is incorporated should include a suitable work stop control such as that described and illustrated schematically in FIG. 25 of Silven et al. patent, No. 2,780,895

i issued February 1, 1957, so that the face plates 15 and 16 are always brought to rest for unloading and loading successive workpieces in the respective positions illustrated in FIGS. 1, 3, and 7, and in FIGS. 2, 4, 6 and 8. With the respective face plates so disposed, the workpieces supported by the respective pot chucks may be removed from and deposited in the pot chucks by a work loader mechanism such as that illustrated in Narel et al. patent, No. 2,813,380 when the clamping jaws of the respective pot chucks 17 and 18 are released and withdrawn from engagement with the crankshaft supported thereby.

It will be noted from the showing in each of FIGS. 1 through 8 that the pot chucks 17 and 18 are mounted in the same relative positions on face plates 15 and 16 for grinding each of the crankpins #2, #3, #4, and #5 of the crankshaft 21 illustrated in FIG. 9, notwithstanding the fact that the respective portions of the angular work locator assembly are positioned differently on the respective pot chucks in order to position each of these crankpins in a proper angular orientation for grinding.

In order to accommodate the attachment of. the respec-' tive portions of the angular work locator assembly in different positions on the respective pot chucks, the threaded holes 53 and 66 and the locating holes 56 and 65 are provided in the proper locations on each of the pot chucks 17 and 18, includingthe provision on each of the pot chucks of duplicate sets of the threaded hole 66 and the locating holes 65.

The proper angular orientation of crankpin #2 is achieved in the manner illustrated in FIGS. 1 and 2 by means of an angular work locator assembly including an adjustable fixedly positioned fixed locator portion generally designated by reference numeral 41 and'by a fixedly positioned resilient locator portion 61, respectively secured to pot chucks 17 and 18 and respectively arranged to engage 'crankpins #6 and #1 adjacent the opposite ends of crankshaft 21.

The fixed locator portion 41 includes a generally rectangular plate 42 with a corner cut away to provide a diagonal crankpin engaging face 43 and fixedly secured by means of threaded bolts 46 and 48 and cooperating nuts 47 and 49 to a mounting ring 51 in turn fixedly secured to pot chuck 17 by means of a plurality of machine screws 52 threadably engaging threaded holes 53 in the pot chuck 17. In order to insure repetitive precision positioning of the mounting ring 51 in relation to the pot chuck 17, the mounting ring 51 may be provided with a pair of locating pins 55 fixedly secured in suitable apertures through the mounting ring 51, and projecting from the mounting ring 51 for engagement with suitable locating holes 56in the surface of pot chuck 17.

Theresilient locator portion 61 comprises a mounting bracket 62 attached to the pot chuck 18 by a machine screw 63 engaging a threaded hole 66 and properly angularly oriented in relation to thepot chuck by means of a pair of locating pins 64 fixedly secured in suitable aperwith a retaining nut 73. The plunger 72 is provided with an enlarged head 74 for engagement with the surface of a crankpin which also serves to engage a biasing spring 75 disposed between the lower surface of the head 74 of the plunger 72 and the upper surface of the supporting bracket 62. The biasing spring 75 must be selected to be strong enough to bias the crankshaft 21 into engagement with the surface 43 of the rectangular plate 42, but preferably should not be strong enough to lift the crankshaft 21 out of engagement with the half bearing of the pot chuck.

In order to properly position crankpin #3 for grinding, the fixed locator portion 41 must be arranged as shown in FIG. 5 with the rectangular plate 42 mounted on pot chuck 17 with its diagonal surface 43 on the right hand side instead of on the left hand side as shown in FIG. 1, and the resilient locator portion 61 must be mounted in an alternate set of holes 65 and hole 66 on the right hand side of pot chuck 18 as shown in FIG. 6 in contrast to the arrangement illustrated in FIG. 2 in which the resilient locator portion 61 is mounted on the left hand side.

In order to provide properly oriented locating pins 55 and to accommodate adjustable mounting provisions for rectangular plate 42 described further below, the fixed locator portion 41 employed with pot chuck 18 includes the rectangular plate 42 and a mounting ring 51' as illustrated in FIGS. 4 and 8 corresponding to but on the opposite hand from mounting ring 51 used with pot chuck 17.

In order to properly position crankpin #4 for grinding, the positions of the fixed locator portion 41 and the resilient locator portion 61 illustrated in FIGS. 1 and 2 must be reversed. That is, the fixedlocator portion 41 must be mounted on pot chuck 18 as shown in FIG. 8 instead of pot chuck 17 as shown in FIG. 1, with the rectangular plate 42 attached to a corresponding mounting ring 51 and positioned in the same orientation relative to the I crankshaft as that'illustrated in FIG. 1 and the resilient tures in themounting bracket 62 and projecting therefrom a the threaded end of a plunger 72 projects for engagement locator portion 61 must be secured to pot chuck 17 as shown in FIG. 7 in a position corresponding to its location on pot chuck 18 illustrated in FIG. 2.

In order to properly position crankpin #5 for grinding, the arrangement of the fixed locator portion 41 and the resilient locator portion 61 illustrated in FIGS. 5 and 6 must likewise be reversed, that is, the fixed locator portion including plate 42 and ring 51 must be mounted upon pot chuck 18 as shown in FIG. 4 instead of pot chuck 17 as shown in FIG. 5 with rectangular plate 42 disposed in a position corresponding to that illustrated in FIG. 5 relative to the crankshaft 21, and with resilient locator portion 61 secured to pot chuck 17 as shown in FIG. 3 instead of pot chuck 18, but in a corresponding position, as shown in FIG. 6.

While in theory it should be feasible to secure the rectangular plate 42 in either position on mounting ring 51 or on mounting ring 51' by means of threaded bolts 46 and 48 and cooperating nuts 47 and 49 passed through precisely sized and positioned holes in the respective parts thus interconnected. However, in practice, it proves desirable to provide for precise preliminary orientation of the fixed surface 43 of rectangular plate 42. One suitable arrangement for providing such precise preliminary orientation is illustrated by the detailed showing in FIGS. 10 and 11. In the configuration illustrated, the portion of bolt 46 passing through the rectangular plate 42 has an enlarged portion 81 intcrfitted with an opening 91 in an eccentric bushing 92 rotatable within an opening through the plate 42 to angularly adjust plate 42 about bolt 48. In order to accommodate the displacement of the plate 42 due to the rotation of the eccentric bushing 92, the opening through the plate 42 accommodating bolt 48 is elongated as illustrated in FIG. 10. When the eccentric bushing 92 is disposed in the desired orientation relative to plate 42, it may be secured by tightening a set screw 93. The plate 42 is properly positioned axially of the bolt 46 by an enlarged shoulder 82 provided on its opposite sides with flats 83 to provide surfaces for engagement by a wrench in order to rotate the bolt 46. The bolt 46 and the bolt 48 are provided with enlarged eccentric portions 84 rotatable in suitably spaced openings through the mounting rings 51 and 51'. These enlarged eccentric portions 84 may be formed integrally with the respective bolts or they may be threadably engaged therewith as illustrated in FIG. 11 and be secured thereto by lock nuts 85. In order to maintain the respective bolts 46 and 48 in engagement with a mounting ring, the rotatable eccentric portions 84 thereof are provided with concentric head portions 86 rotatable in suitable recesses adjacent to the openings through each mounting ring which accommodate the respective eccentric portions 84. The respective eccentric portions 84 are arranged to be rotated in unison about parallel axes to shift the rectangular plate 42 either to one side or to the other as desired. When these eccentric portions 84 and the respective bolts 46 and 48 of which they are a part are properly angularly oriented, they may be secured against rotation by tightening set screws 87 engaging annular grooves 88 in the respective eccentric portions 84. By means of these various adjustable elements the rectangular plate 42 included in the fixed portion of the angular work locator assembly of the instant invention may be precisely positioned in the desired orientation after which it is fixedly secured in this orientation. In order to reverse the disposition of the crankpin engaging face 43, it is simply necessary to remove the nuts 47 and 49 so that plate 42 and the eccentric bushing 92 may be removed from the respective bolts and reversed so that the eccentric bushing 92 encircles bolt 48 and the elongated opening in plate 42 engages bolt 46. Thereafter replacement of the nuts 47 and 49 will secure the plate 42 in its new position with suitable adjustment of the respective eccentric portions if necessary.

Thus, the instant invention provides an angular work locator assembly for use with a pair of opposed pot chucks including portions operatively connected to each of the respective pot chucks adjustable relative to the respective pot chucks so that the respective portions of the angular work locator assembly coact in their respective positions to position a workpiece in various desired angular orientations relative to the pot chucks by engagement with portions of the workpiece adjoining the respective pot chucks.

Accordingly, the instant invention is particularly well suited for angularly positioning workpieces such as crankshafts for grinding crankpins intermediate the ends of a crankshaft rather than the cnankpins immediately adjacent the ends of a crankshaft. Therefore, the teachings of the instant invention may conveniently be combined with the teachings of Smith Patent No. 2,950,586 to provide means for precisely positioning a crankshaft in the proper angular orientation for grinding any one of the crankpins on a crankshaft including those adjacent the ends. Thus the arm 90 disclosed in Smith Patent No. 2,950,586 may be mounted as shown in FIG. 2 of Smith Patent No. 2,950,586 on pot chuck 17 to engage crankpin #6 to properly position crankpin #1 for grinding. Alternatively, the arm 90 may be mounted in a corresponding location on pot chuck '18 to engage crankpin #1 to position crankpin #6 for grinding. For this purpose, each of pot chucks 17 and 18 is provided with a threaded hole 101 to receive a stud to provide pivotal support for an arm corresponding to arm 90 in Smith Patent No. 2,950,586. In addition, each of pot chucks 17 and 18 is provided with a threaded hole 102 to receive an attachment screw for a bracket corresponding to bracket 94 of Smith Patent No. 2,950,586. Finally, each of pot chucks 17 and 18 is provided with a stop pin 103 adjacent to hole 102 corresponding to stop pin 95 of Smith Patent No. 2,950,586. Thus when mounting ring 51 is removed from pot chuck 17 or when mounting ring 51 is removed from pot chuck 18, a workpiece position- 6 ing arm as taught in Smith Patent No. 2,950,586 may be substituted therefor. When the arm replaces the fixed portion of the angular work locator assembly described above on one pot chuck, the resilient portion of the angularly work locator assembly is also removed from the other pot chuck since the arm performs the function of both of these portions.

In an alternative embodiment the necessary mounting holes and the stop pin for the arm assembly may be provided in each of the mounting rings 51 and 51' so that the arm may be more readily installed on the mounting ring after removal of the plate 42. In order to accomplish this result, the configuration of the mounting ring could be modified to encompass the holes 01 and 102 and the stop pin 103 or the configuration of the arm employed could be modified to bring these holes and this stop pin within the peripheral limits of the existing mounting rings for this purpose.

It is to be understood that the embodiment of the instant invention described above and illustrated in the drawings is exemplary only and that various modifications of this device are contemplated within the scope of the ipstant invention as defined by the several claims appended ereto.

What is claimed is:

l. A crankpin positioning mechanism comprising a pair of axially aligned opposed work supporting pot chucks secured eccentric-ally of and in fixed angular relation to a pair of rotatably mounted spaced coaxial face plates for supporting the opposite ends of a crankshaft I concentric with the axis of rotation of the crankshaft, lo-

eating means including a portion mounted on each of said pot chucks for engagement with crankpins of a crankshaft respectively adjacent tosaid pot chucks, said pot chucks universally adapted for mounting the respective portions of said locating means at different coordinated positions thereon for fully constraining a crankshaft against angular displacement in either direction and simultaneously precisely positioning each of different intermediate crankpins of a crankshaft for rotation about its own axis.

2. A crankpin positioning mechanism for a crankshaft grinding machine comprising a pair of rotatable pot chucks supporting opposite ends of a crankshaft with its axis offset from the axis of rotation of said pair of pot chucks and a crankpin to be ground, a resilient locating means mounted on one of said pair of pot chucks, an adjustably fixed locating means mounted on the opposite one of said pot chucks, said resilient and fixed locating means being selectively and interchangeably mounted in difierent positions on each of or either of said pot chucks for fully constraining a crankshaft against angular displacement in either direction and for selectively precisely positioning the axis of each of different crankpins of a crankshaft coincident with the axis of rotation of said pot chucks.

3. A crankpin positioning mechanism for a crankshaft grinding machine having a pair of aligned spaced rotatable pot chucks supporting the opposite ends of a crankshaft, comprising interchangeable locating means each arranged to be mounted in different locations on each of said pot chucks for engagement with a crankpin adjacent to each of said pot chucks and respectively disposed in their different locations so as to coact to prevent the rotation of a crankshaft in either direction for precisely positioning the axis of each of difierent crankpins to be ground on the axis of rotation of said spaced rotatable pot chucks.

4. A11 angular workpiece positioning mechanism comprising a pair of work supports for supporting the opposite ends of a workpiece having a plurality of offset portions angularly disposed about its axis, a first means mounted in one of several predetermined positions on one of said work supports for engaging the offset portion adjacent to one of 'said work supports, a second means mounted on the other of said work supports in a coordinated one of several predetermined positions for engageither direction relative to said work supports, for selectively precisely angularly positioning various other offset portions of a workpiece.

5. A workpiece positioning mechanism comprising a pair-of work supports for supporting the opposite ends of a workpiece having offset portions thereon, a first means mounted on one of said work supports for engaging one of said ofiis'et portions, 21 second means mounted on the.

other of said work supports for engaging another of said offset portions, said first and second means being interchangeable for-mounting in different predetermined co ordinated positions in opposed relation on either of the respective work supports for engagement with opposed surfaces of said respective ofiset portions of a workpiece. 6. A workpiece positioning mechanism comprising a adjacent to the other work pair ofwork supports for supporting the opposite ends of a workpiece having ofiiset portions disposed at spaced intervals about its axis, a first means mounted on one of said work supports for engaging the offset portion adjacent to one of said work supports, a second means mounted on the other of said work supports engaging another oiI'set portion adjacent to the other work support,

said first and second means being interchangeable for mounting in different coordinated locations on each of or either of said Work supports forengagernent with adjacent otlset portions of a workpiece in mutually opposed relation thereto to prevent rotation of a workpiece in either direction relative to said Work supports.

References Cited in the file of this patent UNITED STATES PATENTS Stoner May 1, 1923 Smith Aug. 30. 1960

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