US2487201A

US2487201A - Machine for finishing or grinding arcuate surfaces

Info

Publication number: US2487201A
Application number: US630651A
Authority: US
Inventors: John Van Buren
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-11-24
Filing date: 1945-11-24
Publication date: 1949-11-08
Anticipated expiration: 1966-11-08

Description

1948 J. VAN BUREN 3 MACHINE FOR FINISHING OR GRINDING ARCUATE SURFACES New 4 Sheets-Sheet 1 Filed Nov. 24, 1945 R om n T N NP R w m N T I A QR mm J. VAN BUREN NM? 8, 1949 2,47,2m1 MACHINE FORFINISHING OR GRINDIING ARCUATE SURFACES 4 SheetsSheet 2 Filed NOV. 24, 1945 llll O 0 Q8 Qw IINVENTOR Hues/v Joy/v l A/V ATTORNEY Ngv. 2949 J. VAN BUREN 7 MACHINE FOR FINISHING 0R GRINDING ARCUATE SURFACES Filed Nov. 24, 1945 4 Sheets-Sheet s O 60 58 S INVENTOR l l JOHN VAN Bun/51v BY //0 A ATTORNEY NW. 8, 394 J. VAN BUREN MACHINE FOR FINISHING OR GRINDING ARCUATE SURFACES 4 Sheets-Sheet 4 Filed NOV. 24, 1945 INVENTQR BURL Jaw/v VA/V Patented Nov. 8, 1949 orrice MACHINE FOR FINISHING OR GRINDING ARCUATE SURFACES John Van Buren, Brooklyn, N. Y. 7 Application November 24, 1945, Serial N0. 630,651

'2 Claims. (c1. 51 101)' This invention relates ing or grinding arcuate surfaces.

. The invention has been particularly worked out in connection with a machine for grinding. or finishing the arcuate surfaces of a cam groove. It is a comparatively simple matter to grind or finish evenly and smoothly concentric portions of cam grooves but it is olifiicult to give an even, smooth finish to the portions of the cam groove which are eccentric to or irregularly related to the axis of rotation of the cam.

This invention has for its object to automatically adjust or regulate the relative positions of a cam or a member having a curved surface to be finished and the finishing member or tool, such as a grinder, in such a manner that the walls of the cam groove or the arcuate or curved surfaces to be finished will be evenly and smoothly finished.

to a machine for finish- Another object of the invention is to provide .20

tool adjusting mechanism for a rotatable tool so constructed and arranged that the center of rotation' of the tool and the point of contact of the tool periphery with the curved or arcuate surface being finished will be automatically maintained on a radius of curvature of the surface being ground.

Further objects ofthe invention will appear from the following specification taken in connection with the drawings which form a part of this application, and in which Fig. 1 is a vertical sectional elevation of a machine constructed in accordance with the invention;

Fig. 2 is a top plan View of the machineshown f in Fig. 1, parts being omitted for the sake of clearness;

Fig. 3 is an elevational view looking in the opposite direction from Fig. 1 and showing particularly the driving connections for reciprocating Y the tool, parts being omitted for the sake of clearness;

Fig. 4 is a vertical sectional elevation taken substantially on line 4-4 of Fig. 1, looking in the direction of the arrows;

Fig. 5 is a transverse sectional plan taken substantially on line 5-5 of Fig. 4, looking in the direction of the arrows;

Fig. 6 is an elevational view taken substantially on line 66 of Fig. 1, looking in the direction of the arrows;

Fig. 7 is a vertical elevational view, partly in section, taken substantially on line 1-1 of Fig. 1, looking in the direction of the arrows;

Fig. 8 is a sectional elevation taken through the control cams and the mounting thereof;

Fig. 9 is a diagrammatic elevational view illustrating the cam to befinished. grinding wheel, and showing the I angular adjustments of the grinding wheel support;

Fig. 10 is a diagrammatic elevational view illustrating the cam which controls the raising and lowering of the cam having a groove to be ground; and

Fig. 11 is a diagrammatic elevational view illustrating the cam which automatically controls the oscillation of the grinding wheel.

The invention briefly described consists of a machine having a support for the cam having the groove to be finished, a tool support ora support for the grinder, and two sets of automatically operated control mechanisms, one set being controlled in its operation by a cam which .causes the cam having the groove to be finished to be vertically adjusted to maintain the rotatable finishing tool or grinding wheel in contact with the surface to be finished and the other set being automatically controlled bye. second controlcam which oscillates the tool support and, therefore, the tool, in such a manner as to always maintain the point of contact of the periphery of the grinding wheel or tool and the axis of rotation of the grinding wheel or-tool on a radius extending from the point of contact to the center of curvature of the surface being finished. Further details of the invention will appear from. the following description.

In the particular embodiment of the invention illustrated in the drawings, the machine is mounted on a base or table 20, von one end of which is mounted a vertical casing 21. In the casing 2| are mounted two vertical posts 22 and two sets of rollers, the rollers at the top of the carriage being designated 26 and 21 and the rollers at the bottom being designated 28 and 29. These rollers engage the oppositely facing inside cylindrical portions of the posts 22 and 23 and center the carriage between the posts.

The carriage also carries two other sets of rollers adjacent the lower end thereof and adjacent the upper end thereof. The two sets of rollers at the lower end of the carriage are shown in the section illustrated in Fig. 5, one set being indicated at 30 and 3 l and the other set being shown at 32 and 33. The uppersets of rollers corresponding to the rollers 30, 3|, 32 and 33 are mounted on the carriage in the same manner as the lower set, one pair of the upper set being shown at 35 and 36 and the other pair being directly in back of this pair,- viewing Fig. 4, one of the rollers of the other pair being shown at 31 in Fig. 1.

By means of the rollers above described, the carriage 25 is guided in its vertical reciprocation. The weight of the carriage and the parts carried thereby is partially counterbalanced by a weight W, shown in Fig. 4; which is connected by a cable 40 around pulleys or wheels M and 42 to the upper end of the carriage, as shown at 43.

The carriage 25 has laterally extending guide brackets 45 and 46, as shown in Fig. 1, in which is slidably mounted a vertical reciprocatable bar 41, this bar being supported by and pulled upwardly by springs 48 and 49.

Raising and lowering control mechanism The carriage 25 is provided with bearings 50 and I in which is rotatably mounted a shaft 52 on the outer end of which is secured the cam C having a groove 53, the walls of which are to be ground or finished. The shaft 52 has mounted thereon a worm gear 55 which meshes with a worm 56 carried by a shaft 51 mounted in a suitable bearing 58 which is connected to and carried by the carriage 25. The shaft 51 has a bevel gear 60 at the lower end thereof, viewing Fig. 4, and this gear meshes with a bevel gear 6I carried by a shaft 62 mounted in a bearing on bracket 59 carried by and connected to carriage 25. Shaft 62 is connected by a universal joint 63 and a telescopic driving connection 34 to a shaft 65, which in turn. is connected by a universal joint 66 to a shaft 61 which is driven by a motor M.

Through the driving connections just described, the motor drives the shaft 52 and thus rotates the cam C having the groove 53 to be finished.

The carriage 25 is controlled as to its vertical adjustment by means of a cam I0 secured to a sleeve 1I pinned to the shaft 52 (see Fig. 8). The cam is in turn supported on a roller 80 rotatably mounted in the upper end of a post 8| which extends upwardly through the table and bottom of the casing 2|. This post BI is vertically adjustable in the following manner. The lower end of the post is threaded into a sleeve 82 which is rotatably mounted in a bracket 83 in such a manner that the sleeve can rotate but cannot move axially. The sleeve 82 has mounted thereon a worm gear 84 which meshes with a worm 85 carried by a spindle 86, to the outer end of which is secured a dial or handle 81. By rotating the dial 81 the sleeve 82 will be rotated and will adjust the post 8| vertically, thereby raising or lowering the roller 80 which supports the cam 10, and the vertical position of the cam 10 determines the vertical position of the carriage and of the cam C which is carried by the shaft 52 mounted in bearings carried by the carriag 25. As the shaft 52 is rotated in the manner above described, the cam 10 will also be rotated. This cam is supported on roller 80 and since the cam is non-circular, as the cam rotates the shaft 52 and work C will be raised or lowered in accordance with the contour of cam 10.

If a single cam surface were being ground, instead of a' cam groove, the grinding wheel could be made the same size as the follower on the con trol cam 10 and this cam alone could control the movement of the cam C to be ground. However, when a cam groove is being ground, the grinding wheel must have a diameter materially smaller 4 than the width of the groove and the axis of the grinding wheel must be angularly shifted when the curvature or are of the cam changes centers and radii, or the grinding wheel will not grind the true arc.

Angular adjustment control mechanism for tool support and tool The tool, which in this instance consists of a grinding wheel carried by a shaft 9|, is mounted in the manner hereinafter described in a bracket which is angularly adjusted and is, through intermediate connecting mechanism, supported on a casing 92 mounted on the table 20. The casing 92 is provided with suitable bearings 93 for a shaft 94, on the outer end of which is mounted a sprocket wheel 95 which is connected by a chain 96 to a sprocket wheel 91 carried by the upper end of the casing 92. The sprocket wheel 91 is mounted on a shaft 98 which is connected by a universal joint 99 and a telescopic driving connection I00 to a shaft IOI, which in turn is connected through a universal joint I02 to a shaft I03 mounted in bearings I04 formed on the carriage 25. The opposite end of the shaft I03 has secured thereto, a spur gear I06. This gear meshes with a rack I01 formed on the vertically reciprocatable bar 41. The bar .41 has mounted thereon and extending laterally therefrom, a boss I08, on the outer end of which is mounted a roller I09. The roller I09 is held in engagement with the periphery of the oscillating control cam 0 which is mounted on the sleeve 1I carried by the shaft 52. The roller is held in engagement with the outer periphery of the cam by means of springs 46 and 49. The bar 41 is provided with a longitudinal slot I I5 through which the shaft 52 extends.

As the bar 41 is raised and lowered by the action of cam IIO, the rack I01 will cause the gear I06 to rotate, thus rotating the shaft I M and through the sprocket and gear connections described, rotating the shaft 94. The axis of rotation of the shaft 94 is indicated at X on Fig. '7.

The inner end of the shaft 94 has secured thereto and extending downwardly therefrom, a crank arm IIG, to the lower end of which is secured a roller II1 which is guided between an arcuate guiding member H8 and a surface II9 carried by the outer surface of the casing 92.

The crank arm II6 has secured thereto and extending laterally therefrom, a bar or supporting member I25, to the other end of which is secured a vertical downwardly extending bracket or support I26 having a dovetail groove or guideway I21 (see Fig. 2) in which is vertically adjustable, a bracket I30. The bracket I30 is vertically adjusted by a thumb screw I3I and is locked in adjusted position by a lock screw I33.

The bracket I30 slidably supports, in a manner about to be described, a sleeve I31 which carries the grinding wheel shaft 9i. This sleeve is supported between sets of vertical and horizontal rollers. In Fig. 1 there are shown two rollers I35 and I36 which are adjustably mounted and are positioned below the sleeve I31 in which the shaft 9I is mounted. A third roller I38 is also adjustably mounted and engages the upper surface of the sleeve I31 and thus the sleeve is held in vertical position by the two lower rollers I35 and I33 and the upper roller I38. The sleeve is supported against lateral movement in a horizontal plane by two rollers I40 and HI which engage one side of the sleeve and a third roller I42 which engages the other side of the sleeve,

-points P, Z and X on .slidably mounted =thes'erollers all being adjustably mounted in the bracket I30.

Attention is called to the fact that the axis of the shaft 9| which is indicated on Fig. 7 at Z is displaced from the axis X of rotation of the shaft 94. Due to this offset relation between the axes X and Z it will be evident that the oscillation of the shaft 94, by reason of the vertical movement of the bar 41 controlled by the cam I II), will cause the crank arm II 6 and the bracket I30 to be oscillated, thus regulating the position of the grinding wheel 90 in such a manner that the point of contact of the grinding wheel with the surface being ground and the axis of rotation of the grinding wheel will be disposed on the radius of curvature of the surface being ground which is drawn from said point of contact to the center of curvature.

As above explained, the cam 10 controls the position of the center of the cam C but the point P or point of contact between the grinding wheel 90 and the surface being ground and the axis Z of the grinding wheel shaft 9| do not lie on a radius about the axis Y of the cam except when the surface being ground lies in an are about the axis Y as a center.

Thus, as the center of curvature of the surface being ground changes, the arm IIG carrying the axis Z of the grinding wheel 90 must be swung through an angle in order to bring the a radius passing through the new center of curvature. This angle, through which the axis Z must be swung, is the angle F in Fig. 9.

In addition to a rotating movement, the shaft 35 9| and sleeve I 31 are reciprocated in the roller mounting described. The shaft is rotated in the following manner. A cylindrical pulley I50 is mounted on the shaft 9| and is driven by a belt |I from a grooved pulley I52 mounted on the shaft of a motor I53. The motor I53 is carried by a bracket I54 mounted for vertical adjustment on the casing 92.

The sleeve I31 and shaft 9| are reciprocated in the following manner. The sleeve I31 has secured thereto and projecting laterally therefrom, a plate l55, 0n the opposite faces of which are positioned rollers I56 and I51 which are carried by a bar I58 which, as shown in Fig. 2, is

92, viewing Fig. 2. The bar I58 has secured thereto a, pin I59 which is positioned in a slot I60 formed in the upper end of a link IBI, the lower end of which is mounted on a fixed pivot I62. Intermediate its mounted thereon a roller I63 peripheral surface of a cam I64 mounted on a shaft I65 carried by brackets I66. The roller I63 is held in contact with the periphery of the cam I34 by means of a spring I61.

The shaft I65 has mounted thereon a worm wheel I 10 which meshes with a worm I1I carried bya shaft I 12. shaft I12 has secured thereto a spur gear I13 which is driven by a gear I14 carried by the shaft 61. Thus the sleeve I31 and shaft 9| will be reciprocated by means of the cam I 64 and link I6I.

Figs. 9, 10 and 11 illustrate diagrammatically the angular adjustment of the tool support when the surface of the groove in the cam 0 changes from an arc concentric with the axis of rotation of the cam to arcs drawn about centers eccentric which engages the to the center of rotation of the cam C. In Fig. 9

the roller which operates in the cam groove 53 during the use of the cam is indicated at R.

on the rear face of the casing I 5 ends the link I6I has 0 The grinding wheel 90 can be used to grind the outer wall I15 of the cam groove- 53 or the inner wall I16 thereof. The position of the grinding wheel 90, in order to grind the inner 5 or outer grooved wall or surface, is determined by the vertical adjustment of the bracket I30.

In the particular cam groove illustrated in Fig. 9, the portion of the cam between the points A and B in an anti-clockwise direction is con- IO centric with reference to the axis of rotation Y of the cam C having the groove being ground. The axis Z of the grinding wheel 90, the axis X of the shaft 94-, and the point P of contact be tween the wheel 90 and surface I15, are located I5 on a radius about Y as a center. However, the portion of the cam groove between the points B and D is drawn on a curve having its center at the point E. In order to maintain the point of contact P between the grinding wheel 90- and 20 the surface being ground between the points 3 and D, the axis Z of the grinding wheel shaft 9| and the axis X of the shaft 94 on a radius drawn through the center E of curvature of the arc B, D, the position of the axis Z of rotation of the grinder shaft 9| must be angularly displaced and this is accomplished by means of the cam IIO which is so designed that the crank arm II6 will [be oscillated in a manner to maintain the point P and the axis Z on the radius I80 drawn between the center of curvature E of the arc B-D and the point P. The angle between a radius passing through the axis Y of the cam C and the axis X of the shaft 94 and between the center ofthe curvature E of the arc 3-D and the axis X, is shown at F. In other words, the angle F represents the angular ad,- J'ustment necessary to maintain P, Z and X on the radius I80 of the arc B, D. It will be noted that this angle varies from the point B to the 40 point D. Moreover, when the grinding wheel is engaging the portion of the wall I15 between the point D and the point G, the grinding operation is taking place on an arc drawn about the center H. This necessitates a further angular adjustment of the axis Z. The portion of the surface I15 between points G and A has a curvature drawn about the center I.

By means of the particular design of the cam IIO, this angular adjustment of the tool support 0 is so regulated that the grinding wheel 90 will be maintained in a position in which the pointP and the point Z will always be located on the radius I80 from the point E to the point P when the surface being ground is disposed between the points B and D. When the surface disposed between the points D and G is being ground, the grinding wheel will be so adjusted that the point of contact P between the grinding wheel and this portion of the surface and the axis Z of the grinding wheel will be located on a radius drawn between the center H and the point P. Furthermore, as hereinbefore stated, whenever the surface I 16 is to be ground or finished, the tool is vertically adjusted by the vertical adjustment of the bracket I30 and the angular displacement of the tool support is accomplished in the same manner as that above described.

Referring to Fig. 10, attention is called to the fact that the contour of the cam 10 follows or is the same as the curvature of the surface I16 of the cam C. In Fig. 11 the cam I I0 follows the curvature of the path of movement of the axis X of shaft 94. The cams 10 and H0 as shown are larger than the cam surfaces of cam C in order to obtain greater accuracy in the cam and tool adjustments.

From the foregoing specification it will be clear that by means of the two control cams and the mechanism operated thereby, the walls of a cam groove or any arcuate surface can be evenly and smoothly finished regardless of the displacement of the center of curvature of the arcuate surface from the axis of rotation of the member on which the surface is formed.

Although one specific embodiment of the invention has been particularly shown and described it will be understood that the invention is capable of modification and that changes in the arrangement and in the construction of the various cooperating parts may be made without departing from the spirit or scope of the invention, as expressed in the following claims.

What I claim is:

1. A machine for finishing cam grooves in a cam comprising a support for the grooved cam to be finished, a tool support for rotatably supporting a finishing tool, a rotatable tool mounted on the tool support means for vertically adjusting the support for the cam to be finished, means for rotating said cam, and means for angularly adjusting said tool support to maintain the point of contact between the tool and surface being finished and the axis of rotation of the tool on the radius of curvature of the surface being ground.

2. A machine for finishing cam grooves in a cam comprising a support for the grooved cam to be finished, a tool support for rotatably supporting a finishing tool, a rotatable tool mounted .on the tool support automatic means including a control cam for vertically adjusting the support for the cam to be finished, means for rotating said cam to be finished, and automatic means including a second control cam and operative mechanism controlled by said second control cam and connected to the tool support for angularly adjusting said tool support to maintain the point of contact between the tool and surface being finished and the axis of rotation of the tool on the radius of curvature of the surface being. ground.

3. A machine for finishing cam grooves in a cam comprising a support for the grooved cam to be finished, a tool support for rotatably supporting a finishing tool, a rotatable tool mounted on the tool support automatic means including a control cam for vertically adjusting the support for the cam to be finished, means for rotating said cam to be finished, and automatic means including a second control cam and vertically adjustable means controlled thereby for angularly adjusting said tool support to maintain the point of contact between the tool and surface being finished and the axis of rotation of the tool on the radius of curvature of the surface being ground.

4. A machine for finishing cam grooves in a cam comprising a support for the grooved cam to be finished, a tool support for rotatably supporting a finishing tool, a rotatable tool mounted on the tool support automatic means including a control cam for vertically adjusting the cam to c be finished, means for rotating said cam to be finished, and automatic means including a second control cam and vertically adjustable means controlled thereby and oscillatable driving connections operated by said vertically adjustable means for angularly adjusting said tool support to maintain the point of contact between the tool and surface being finished and the axis of rotation of the tool on the radius of curvature of the surface being ground.

5. A machine for finishing cam grooves in a cam comprising a support for the grooved cam to be finished, a vertically adjustable tool support for rotatably supporting a finishing tool, a rotatable tool mounted on the tool support automatic means for vertically adjusting the support for the cam to :be finished, means for rotating said cam to be finished, and automatic means for angularly adjusting said tool support to maintain the point of contact between the tool and surface being finished and the axis of rotation of the tool on the radius of curvature of the surface being ground.

6. A machine for finishing cam grooves in a cam comprising a support for the grooved cam to be finished, a tool support for rotatably supporting a finishing tool, a rotatable tool mounted on the tool support means for rotating said tool, means for axially reciprocating said tool, automatic means for vertically adjusting the support for the cam to be finished, means for rotating said cam, and automatic means for angularly adjusting said tool support to maintain the point of contact between the tool and surface being finished and the axis of rotation of the tool on the radius of curvature of the surface being ground.

7. A machine for finishing arcuate surfaces in a blank comprising means for supporting a blank having an arcuate surface to be finished, means for supporting a rotatable finishing tool, a rotatable tool mounted on said tool support, automatically operating means for vertically adjusting said support for the blank, means for rotating said blank, and automatically operating means for angularly adjusting the tool support relative to a radius from the point of contact between the tool and surface being finished and the center of rotation of said blank to maintain the point of contact of the tool and said arcuate surface of the blank and the axis of rotation of the tool on the radius of curvature of said arcuate surface.

JOHN VAN BUREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,924,003 Shaw et al Aug. 22, 1933 2,091,456 Rybick Aug. 31, 1937 2,210,273 Wildhaber Aug. 6, 1940 2,247,412 Rybicky July 1, 1941 2,421,548 Davies June 3, 1947