US3468070A - Metal reed support for oscillating cradle - Google Patents

Description

Se t. 23, 1969 J. R. FRIES ETAL 3,468,070

METAL REED SUPPORT FOR OSCILLATING CRADLE Filed May 16, 1967 4 Sheets-Sheet 1 INVENTORS RALPH E. PR\C E ATTORNEYS Sept. 23, 1969 J. R. FRIES ETAL 3,468,070

METAL REED SUPPORT FOR OSCILLATING CRADLE Filed May 16, 1967 4 Sheets-Sheet 2 2516.2 VJ Ml/i5 a A 85 87 14 W J W I W I, I $56 I [1," 67 M Has 69 INVENTCRS JOHN $2.PR\ES 6n RALPH E. PR\CE ATTORNEYS Se t. 23, 1969 J. R. FRIES ET L METAL REED SUPPORT FOR OSCILLATING CRADLE Filed May 16, 1967 4 Sheets-Sheet L mvsw'rors JOHN lZF-RIES an RALPH E. PRKZE WM yogi/k KT IORNEYS Sept. 23, 1969 J, R, mgs ETAL 3,468,070

METAL REED SUPPORT FOR OSCILLATING CRADLE Filed May 16, 1967 4 Sheets-Sheet 4 I ENTORS JOHN 2.. F ES Cr RALPH E. PRKIE ATTORNEYS United States Patent US. Cl. 51-101 19 Claims ABSTRACT OF THE DISCLOSURE This disclosure involves an improvement in cam grinder construction, particularly in the means for supporting the oscillating cradle. The invention particularly relates to the providing of metal reed hinges in place of the customary bearings for the end portions of the cradle. It also consists of placing similar hinges to connect the cradle and work carriage at one or more intermediate points at or between the headstock and footstock carried by the cradle. The reed hinges for supporting the end portions of the cradle prevent radial displacement of the cradle more effectively than the conventional preloaded roller bearings now customarily used and with substantially less friction. The intermediate hinge or hinges supplement the end hinges and provide the additional result of damping resonance and vibration in the cradle.

This invention relates to a conventional machine for grinding automotive Camshafts and more particularly to improvements in the supports for the cradles which support a camshaft during a grinding operation.

The conventional cradle is customarily supported at each end by means of anti-friction roller or ball bearings. The portion of the cradle between the bearings is supported only by its own structure and, therefore, is subject to undesired vibration and resonance. It is the primary purpose of this invention to effectively damp this vibration and resonance of the cradle without in any way detrimentally restricting the oscillatory movement of the cradle as is required when presenting cam surfaces to a grinding wheel in the grinding of a cam contour.

In the improved cradle mounting, the intermediate portion corresponding generally to the portion between the ends of the workpiece is supported on longitudinally spaced members, each consisting of intersecting metal reeds, one end of which is fixedly attached to the cradle and the other end of each being fixedly attached to the work carriage. These intersecting reeds may also be used in place of the customary anti-friction bearings supporting each end of the cradle. The intermediate intersecting reeds provide a connection between the cradle and the carriage which substantially eliminates vibration and resonance in the cradle. The reeds supporting the end portions of the cradle provide a more rigid support which prevents radial displacemet of the cradle to a greater extent than the anti-friction bearings and, at the same time, operate with even less frictional resistance than the anti-friction bearings.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

In the drawings:

FIGURE 1 is a front elevational view of a cam grinder having the cradle thereof mounted in accordance with this invention.

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FIGURE 2 is an end view of the cradle taken along the line 22 of FIGURE 1, with the carriage being in section, and shows the arrangement of the cradle mounting reeds.

FIGURE 3 is a fragmentary sectional view taken longitudinally of the cradle and shows more specifically the details of the support for the end of the cradle.

FIGURE 4 is an exploded perspective view showing specifically the details of the mounting support carried by the carriage for mounting one end of the cradle, and the metal reeds carried by the mounting support.

FIGURE 5 is a fragmentary end view of the cradle as it appears prior to the attachment thereof to the carriage.

FIGURE 6 is a sectional view taken transversely of the axis of the cradle and shows the general details of the intermediate reed assembly.

FIGURE 7 is a fragmentary sectional view taken along the line 77 of FIGURE 6 longitudinally of the cradle and shows further the details of the intermediate reed assembly.

FIGURE 8 is an exploded perspective view of a mounting support carried by the carriage and forming part of the intermediate reed assembly, there also being shown the reeds.

FIGURE 9 is an enlarged fragmentary sectional view taken through the intermediate portion of the cradle and shows the details thereof with the intermediate reed assembly being omitted.

Referring now to the drawings in detail, it will be seen that there is illustrated in FIGURE 1 a cam grinder which is generally referred to by the numeral 10. The cam grinder 10 is of a conventional construction except for the mounting of a cradle thereof. Accordingly, only those portions of the cam grinder which specifically relate to the invention will be described here.

The cam grinder 10 includes a bed 11 on which there is mounted a carriage 12 for controlled longitudinal movement. The carriage 12 has the upper part thereof in the form of a swivel table 13. A cradle 14 is mounted on the swivel table 13 for oscillating movement about a fixed axis. This invention relates particularly to the mounting of the cradle 14 and the specific details of the cradle mounting will be set forth hereinafter.

The cradle 14 carries a headstock 15 having a headstock center 16 which supports one end of a camshaft C. The cradle 14 also carries a footstock 17 which carries a footstock center 18 which engages and supports the other end of the camshaft C. It is to be understood that the camshaft C is supported for rotation about a fixed axis as defined by the centers 16 and 18. In addition, the camshaft C is suitably rotatably driven.

The cam grinder 10 also includes a grinding wheel support 20 which has mounted thereon for rotation a grinding wheel 21. It is to be understood that the grinding wheel 21 is mounted on the bed 11 for movement transversely of the bed 11, that is normal to the axis of the cradle 14 in order that the grinding wheel 21 may be positioned relative to the camshaft C to effect the necessary cam grinding operation.

The oscillating movement of the cradle 14 necessary to effect the grinding of the desired cam contour is effected in a known manner as disclosed in US. Patent 2,323,189, granted June 29, 1943, in which a master cam is rotatably mounted upon one end of a cradle in axial alignment with a workpiece, and with a rotatable transversely fixed follower arranged to engage the master cam.

In operation, the cradle 14 is oscillated in accordance with the contour of the master cam rotating in engagement with the follower roller as shown in Patent No. 2,323,189. The axis of oscillation of the cradle 14, as

well as the camshaft C carried thereby, is a fixed axis determined by the means mounting the cradle 14. If desired, the support means for the cradle 14 may be the conventional anti-friction bearings customarily used in supporting cradles of cam grinders, although it is preferred that the mounting means be special means in accordance with this invention.

In order to damp vibrations in the intermediate portion of the cradle 14, the cradle 14 is provided with at least one intermediate support and preferably at least two intermediate supports, such as the intermediate supports 22, shown in FIGURE 1. Inasmuch as the construction of these intermediate supports or reed assemblies 22 is identical, the details of only one of the intermediate supports 22 will be set forth here.

Referring now to FIGURES 6 through 9, it will be seen that in the area of the intermediate reed assembly 22, the cradle 14 is of a reduced section. This. section of the cradle 14 presents an abutment 23 on which there is provided a mounting pad 24. The mounting pad 24 presents a generally vertical mounting surface 25 and a generally horizontal mounting surface 26.

With particular reference to FIGURE 8, it will be seen that there is illustrated a mounting support or bracket which is generally referred to by the numeral 27. The bracket 27 incldes a base 28 which is adapted to be seated on the swivel table 13 and which has formed suitable fastener receiving apertures 29. The bracket 27 also has an upstanding leg 30 which is reinforced relative to the base 28 by a central web 31.

It is to be noted that the bracket 27 is machined to define an upper mounting surface 32 on the upstanding leg 30. Also, the web 31 is machined to provide a mounting surface 33 thereon facing upwardly, the surface 33 being disposed immediately adjacent the leg 30. In addi tion, the leg 30 has machined thereon a vertical mounting surface 34 which is disposed immediately adjacent to the surface 33 and intersects the same.

The reed assembly 22 includes three metal reeds 35, 36 and 37. The reed 36 is centrally located and is clamped against the surface 34 by a T-shaped block 38 which is seated on the surface 33 and secured thereto by means of fasteners 40. Other fasteners 41 extend through the reed 36 and into the surface 34. The other end of the reed 36 is provided with a mounting block 42 having fasteners 43 which extend through the reed 36.

The reeds 35 and 37 are disposed on opposite sides of the reed 36 and are clamped to the surface 32 by means of fasteners 44 which pass through blocks 45, the blocks 45 serving as mounting or clamping blocks. The opposite ends of the reeds 35 and 37 are provided with other mounting or clamping blocks 46 which carry fasteners 47 which extend through the reeds.

It is also to be noted at this time that the base 28 is provided with a keyway 48 which receives a key 49 carried by the swivel table 13 and which assures the proper alignment of the mounting support or bracket 27 with the swivel table 13 and the carriage 12. The bracket 27 is releaseably secured to the swivel table 13 on an upstanding portion 50 thereof by means of fasteners 51 which pass through the apertures.

It will be readily apparent from FIGURES 6 and 7 that the upper end of the reed 36 is clamped against the surface 25 by the block 42. In a like manner, the ends of the reeds 35, 37 remote from the bracket 27 are clamped against the surface 26 by means of the blocks 46.

It is to be understood that the intermediate support or reed assembly 22 is positioned with the reeds 35, 36 and 37 lying in planes which are disposed parallel to the axis of pivoting of the cradle 14 and intersecting along that axis. Thus the reeds 35, 36 and 37 function as pivots. It will be readily apparent that inasmuch as the reeds 35, 36 and 37 are relatively stiff, while being sufficiently resilient to permit the pivoting of the cradle, the reeds serve to both support the intermediate portion of the cradle and to damp the normal vibrations and resonance set up in the cradle 14 during a grinding operation.

It is to be understood that any number of reeds may be utilized in each reed assembly, depending upon the specific needs. Also, it is to be understood that the number of intermediate supports or reed assemblies 22 may vary depending upon the particular needs. In the preferred embodiment of the invention, one of the intermediate supports 22 is disposed adjacent the headstock end of the camshaft C while the other of the intermediate supports 22 is disposed adjacent the tailstock end there of. In this manner, the cradle 14 is supported intermediate points Where there is a maximum tendency for vibrations.

Although conventional anti-friction bearings may be utilized to support the ends of the cradle 14 in conjunction with the intermediate supports 22, end portions of the cradle 14 may be supported in a similar manner by reeds, and accordingly, at the opposite ends of the cradle 14 there are end supports, which are generally referred to by the numeral 54. The construction of a typical end support is found in FIGURES 2 through 5.

Each end support 54 includes a supporting mount or bracket 55 carried on swivel table 13 and a supporting mount or bracket 56 secured to the end portion of the cradle 14. Referring to FIGURE 4 in particular, it will be seen that the bracket 55 includes a base 57 which is adapted to be anchored on the swivel table 13 and which has formed in the underside thereof a keyway 58 for alignment purposes. The base 57 is also provided with apertures 60 for receiving suitable fasteners.

The base 57 has extending upwardly therefrom a relatively thick leg 61 which includes an upper mounting surface 62 and a generally vertical mounting surface 63. The upper mounting surface 62 has a keyway 64 formed therein while the vertical mounting surface 63 has a keyway 65 formed therein.

The bracket 55 carries three reeds, two outer reeds 66, 67 which are vertically disposed, and a central reed 68 which is horizontally disposed. The reds 66, 67 are secured to the bracket 55 by generally T-shaped blocks 69, each of which has a horizontal leg of a size to be received in the keyway 65. Each block 69 also has a vertical leg 71 which is adapted to oppose the mounting surface 63 and to clamp the respective reeds 66, 67 thereagainst. The leg 70 carries a fastener 72 and the leg 71 carries fasteners 73, the fasteners 72 and 73 being threadedly engageable into the leg 61 of the bracket 55. The fasteners 73 also serve to secure the reeds 66, 67 to the respective blocks 69.

At the opposite end of each of the reeds 66, 67 is a clamping block 74 having fasteners 75 which extend through the respective reeds 66, 67 to clamp the same against the bracket 56. It is to be noted that the reeds 66, 67 are vertically disposed.

The reed 68 is secured to the bracket 55 by a further T-shaped clamping block 79 which may be of an identical construction with the clamping block 69. The clamping block 76 has a leg 77 which is seated in the keyway 64. A second leg 78 opposes the surface 62 and cooper ates therewith to clamp the end of the reed 68 in place. It is to be noted that the leg 77 carries a fastener 80 while the leg 78 carries a pair of fasteners 81 which se cure the block 76 to the bracket 55. The fasteners 81 also extend through the reed 68 and secure the reed 68 to the block 76.

The opposite end of the reed 68 has secured thereto a clamping block 82 which carriers fasteners 83. The fasteners 83 extend through the reed 68 and are adapted to clamp the reed 68 against the bracket 56. It is to be noted that the reed 68 is horizontally disposed.

Referring now to FIGURES 3 and 5 in particular, it will be seen that the bracket 56 is generally arcuate in outline about its outer periphery and generally angular about its inner periphery. The end of the cradle 14 is recessed as at 85 and the bracket 56 is seated therein and clamped against an end wall 86 of the cradle 14 by a plurality of elongated fasteners 87. The bracket 56 is provided with a pair of reed clamping surfaces 88, 89, the surface 88 being vertically disposed and the surface 89 being horizontally disposed.

It is to be understood that the clamping block 74 will be utilized to clamp the reeds 66, 67 against the surface 88 while the clamping block 82 will be utilized to clamp the reed 68 against the surface 89.

Referring now to FIGURE 2, it will be seen that the bracket 55 is clamped in place on the swivel table 13 by means of fasteners 90 passing down through the base 57 thereof. At the same time, a key 91 carried by the swivel table 13 is seated in the keyway 58 and serves to accurately position the bracket 55 transversely of the swivel table 13. With the bracket 55 so accurately positioned relative to the swivel table 13, and the bracket 56 being accurately positioned on the end of the cradle 14, the axis of pivoting of the cradle 14 will be accurately established. It is to be understood that the reeds 66, 67 lie in a common vertical plane while the reed 68 lies in a horizontal plane and the planes of the reeds intersect along a line which is the axis of pivoting for the cradle 14. Of course, the two supports 54 will have a common povit axis.

It will be readily apparent that the reeds of the end supports 54 will not only function to support the cradle 14 for the necessary pivotal movement, but will also function to damp vibrations and resonance of the cradle 14, which function is not accomplished by the prior used anti-friction bearings.

In operation of the cam grinder 10, the cradle 14 is oscillated in accordance with the contour of the master cam rotating in engagement with the follower roller. The axis of oscillation passes through the lines of intersection of the planes of the vertical and horizontal reeds. The reeds of the end supports function in the same manner as those supporting the intermediate portions of the cradle 14, but provide a further and different result, i.e. preventing radial displacement of the cradle as compared with anti-friction bearings. The only friction involved in the oscillating movement is the internal friction in the reeds. The nature of the reeds is such that they are not subject to radial displacement of the axis of oscillation as woud be the case with ball or roller bearings which are subject to deformation in a radial direction. The connections between the cradle 14 and the swivel table 13 at the intermediate supports not only serve to dampen resonance and vibrations in the cradle 14, but also supplement the end supports in preventing radial displacement of the axis of oscillation of the cradle 14.

Although only a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the various supports without departing from the spirit and scope of the invention, as defined by the appended claims.

We claim:

1. In a machine tool,

(a) a work shaping member,

(b) means for supporting a workpiece for oscillating movement toward and away from said work shaping member comprising (c) a cradle having support means for rotatably supporting a workpiece,

(d) a cradle supporting member having means mounting said cradle for oscillating movement,

(e) a vibration damping means connecting an intermediate portion of said cradle with said cradle supporting member,

(f) and said vibration damping means includes reeds having opposite ends anchored to said cradle and said cradle supporting member.

2. The machine tool of claim 1 wherein,

(a) said reeds are arranged in crossing relation with the line of crossing being along a line between said mounting means.

3. The machine tool of claim 2 wherein,

(a) said mounting means are also in the form of crossed reeds anchored to said cradle and said cradle supporting member.

4. In a grinding machine,

(a) a bed,

(b) a grinding wheel support slidably mounted on said bed,

(c) a grinding wheel rotatably mounted in said wheel support,

(d) a work carriage slidably mounted on said bed,

(e) means for effecting relative transverse and longitudinal movements between said wheel support and said carriage,

(f) means for supporting a workpiece on said carriage for oscillating movement toward and from said grinding wheel comprising g) a cradle,

(h) means for rotatably supporting a workpiece on said cradle,

(i) said cradle being subject to resonannce from the operation of said machine,

(j) means for damping said resonance comprising means connecting an intermediate portion of said cradle with said carriage,

(k) said damping means includes at least one connecting means between said cradle and said carriage,

(l) and said connecting means includes at least one reed connecting said cradle to said carriage.

5. The grinding machine of claim 4 wherein (a) said damping means includes at least two connecting members disposed in longitudinally spaced relation,

(b) and said connecting members are disposed in crossing relation.

6. The grinding machine of claim 4 wherein (a) said reed has one end fixedly secured to said carriage and the opposite end fixedly secured to said cradle.

7. The grinding machine of claim 4 wherein (a) said damping means includes a plurality of said reeds each having one end fixedly secured to said carriage and the opposite end fixedly secured to said cradle,

(b) said reeds being disposed in crossing relation.

8. The grinding machine of claim 4 wherein (a) said means for rotatably supporting a workpiece includes a headstock and a footstock,

(b) and said damping means are disposed intermediate said headstock and said footstock.

9. The grinding machine of claim 4 wherein (a) said damping means includes a set of three reeds including two outer reeds and a central reed,

(b) said reeds lie in planes crossing along a line,

(c) and said outer reeds lie in a common plane.

10. The grinding machine of claim 4 wherein (a) said carriage has supports adjacent opposite ends of said cradle mounting said cradle for pivotal movement about a fixed axis,

(b) said damping means includes a set of three reeds including two outer reeds and a central reed,

(c) and said reeds lie in planes crossing along said 'fixed axis.

11. The grinding machine of claim 10' wherein (a) said supports are each formed of at least two reeds lying in planes crossing along said fixed axis.

12. In a machine tool,

(a) a work shaping member,

(b) means for supporting a workpiece for oscillating movement about a predetermined axis toward and away from said work shaping member comprising (0) a cradle having support means for rotatably supporting a workpiece; and

(d) a cradle supporting member having flexible means disposed at said predetermined axis for mounting said cradle for oscillating movement about said predetermined axis.

13. The machine tool of claim 12 including (a) additional flexible means between said first-mentioned flexible means connecting an intermediate portion of said cradle With said cradle supporting member.

14. The machine tool of claim 12 wherein (a) said flexible means constitute vibration dampening means for dampening resonance to which said cradle is subjected from the operation of the machine tool.

15. The machine tool as defined in claim 13 wherein (a) said additional flexible means constitute vibration dampening means for dampening resonance to which said cradle is subjected during the operation of said machine tool.

16. The machine tool of claim 12 wherein (a) said flexible means include reeds having opposite 25 ends anchored to said cradle and said cradle supporting member.

17. The machine tool of claim 13 wherein (a) said additional flexible means are reeds having opposite ends anchored to said cradle and said cradle supporting member.

18. The machine tool of claim 16 wherein (a) said reeds are arranged in crossing relation with the line of crossing being disposed generally along said predetermined axis.

19. The machine tool of claim 17 wherein (a) said reeds are arranged in crossing relation with the line of crossing being disposed generally along said predetermined axis.

References Cited UNITED STATES PATENTS 138,825 5/1873 Weiss 5ll01 2,323,189 6/1943 Balsiger 5ll0l 2,352,608 7/1944 Archer 51l0l 2,581,759 1/1952 Green 51--101 LESTER M. SWINGLE, Primary Examiner US. Cl. X.R.

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