US3251157A

US3251157A - Grinding fixture

Info

Publication number: US3251157A
Application number: US299290A
Authority: US
Inventors: Jr Edmund L Clark
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-08-01
Filing date: 1963-08-01
Publication date: 1966-05-17
Anticipated expiration: 1983-05-17

Description

May 17, 1966 l E. l.. CLARK, JR 3,251,157

GRINDING FIXTURE Filed Aug. l, 1965 2 Sheets-Sheet 1 May 17, 1966 E. L. CLARK, JR 3,251,157

GRINDING FIXTURE Filed Aug. l, 1963 2 Sheets-Sheet 2 United States Patent O 3,251,157 GRINDING FIXTURE Edmund L. Clark, Jr., 13006 Yukon Ave., Hawthorne, Calif. Filed Aug. 1, 1963, Ser. No. 299,290 4l Claims. (Cl. Sil- 100) The present invention relates to grinding means and more particularly to a fixture for use on a grinder for accurately grinding a predetermined profile onto the cutting edge of a cutting tool.

The majority of drills, cutting tools, etc., have a substantially cylindrical exterior. As a result, these tools can be sharpened by mounting the tool in a chuck wherein the tool may rotate about an axis parallel to the axis of the grinding wheel while the tool is moved axially along this axis. The cutting edge of the tool is placed against the abrasive surface of the grinding wheel. The tool is then rotated about its axis and moves axially parallel thereto as the exterior of the tool is ground by the wheel. However, not infrequently it is necessary for the cutting surfaces of the tool to be contoured or to have a nondcylindn'cal profile. When grinding such tools it is necessary for the tool to move in and out relative to the grinding wheel as it moves axially thereof. Heretofore, in order to accurately grind such tools it has been necessary to employ special contour or profile vgrinding machines that will move the tool in the required manner as it travels past the grinding wheel. Such profile grinders have been specifically designed for grinding the contour onto a tool and as a consequence, have been of 'little value for other purposes. In addition, such machines have been very complex and very expensive. Thus, although they may be capable of accomplishing the desired grinding, they represent a substantial capital investment having limited utility. As a consequence, they are not well suited for use in those installations where it is necessary to -sharpen such a small number of tools that the grinder is not kept in operation a suiiicient amount to pay lfor itself.

It is now proposed to provide grinding means for overcoming the foregoing ditiiculties. More particularly, it is proposed to provide a profile grinding fixture which may be used on a standard or universal grinder. The fixture is sutliciently inexpensive to justify its purchase even though it may not be kept busy all of the time. In addition, the fixture is very simple to4 manufacture and use. More particularly, it is proposed to provide a fixture that may be mounted on the movable table of a standard grinder. The fixture includes a platform that is mounted to move transversely of the table toward and away from the grinding wheel. A tool support such as a pair of tail stocks are mounted on the platform for carrying the tool to be sharpened. In addition, a template and follower are provided which will control the motion of the platform and the tool carried thereby as it is fed axially past the grinding wheel. It may thus be seen that a universal type grinder which may be ernployed for a large number of grinding operations may now be employed to accurately grind any desired profile onto a tool by the use ofthe present simple and inexpensive fixture.

These and other features and advantages of the present invention will become readily apparent from the following detailed description of one embodiment thereof, particularly when taken in connection with the accom- FIGURE 2 is a plan view of a portion of the grinder and fixture of FIGURE 1;

FIGURE 3 is an end view of the xture and grinder of FIGURE l;

FIGURE 4 is a .perspective View of the fixture with portions thereof broken away;

FIGURE 5 is a longitudinal cross-sectional view taken substantially along the plane of line 5 5 in FIGURE 3;

FIGURE 6A is a view of the fixture set up in a first manner; and

FIGURE 6B is a View of the first set up in a second manner.

Referring to the drawings in more detail, the present invention is particularly adapted to be embodied in a fixture 10 for use on a grinder 12 of any desired variety.

This grinder 12 may be of any desired variety. Forexample, the grinder 12 may be astandard or universal grinder that is eective to perform a wide variety of grinding operations. Normally, such a grinder employs a stand 14 adapted to be secured to the floor in a fixed solid position. The stand 1d may include a vertical support 16 that extends upwardly from one side of the stand 14. A suitable drive motor 18 may be secured to this support 16 so that the drive shaft thereof will be substantially horizontal and extending parallel to the length of the grinder 12. A spindle 20 may be provided on the end of the drive shaft for having a grinding wheel mounted thereon. The axis of the motor 13 and the spindle 2li are thus substantially horizontal and extend longitudinally of the grinder 12 while the grinding wheel 22 revolves in a substantially Vertical plane disposed transversely of the grinder 12.

A cross slide 24 may be provided on the top of the stand 14. The cross slide is preferably mounted on a pair of ways which are substantially normal to the axis of the motor and parallel to the plane of the grinding wheel. A lead screw having a cross feed hand wheel 26 thereon may be provided for driving the cross slide along the ways. It will thus be seen that by manipulating the hand wheel 26 the cross slide 24 can be made to move toward and away from the grinding wheel 22 without producing any motion in a longitudinal direction or parallel to the axis of the grinding wheel 22.

In addition, a bed 28 may be mounted on top of the cross slide 24. This bed 2S is carried by the cross slide 24. Thus, turning the hand wheel 26 will cause the cross slide 24 and the bed 28 thereon to move transversely of the grinder 12 toward and away from the grinding wheel 22. This bed 28 may also be mounted on a pair of parallel ways so that it will be free to slide thereon. These ways are normal to the ways for the cross slide and extend in a longitudinal direction parallel `to the axis of the drive motor and the axis of the grinding wheel. A hand wheel 30 may be provided which is peratively interconnected with a lead screw for causing the bed 23 to be driven in the longitudinal direction parpanying drawings wherein like reference numerals refer allel to the axis of the grinding wheel 22.

An elongated table 32 may be mounted on top of the bed 28 so as to extend substantially longitudinally of the grinder 12. This table 32 may be rigidly secured to the bed by means of one or more clamps 34. An elongated track or keyway 38 may be provided that extends axially the full length of the' table 32. This keyway 38 includes al relatively narrow opening with an enlarged inner portion that forms a shoulder. Thus, a bolt may be provided so that the shank thereof will bite through the opening but the head will engage the shoulder and be secured thereagainst.

Normally, the table 32 will be secured to the bed 28 so that the track 38 thereon will be substantially parallel to the axis of the shaft and motor. However, by releasing the clamps 34 the table 32 will be released so that it may be moved to an oblique position that will be indicated by the protractor 40.

It may thus be seen that by manipulating the two hand wheels 26 and 36, the cross slide 24 and the bed 28 may be made to move respectively toward and away from `the grinding wheel 22 and parallel to the axis of the grinding Wheel 22. Thus, the surface on the top of the table 32 may be made to travel in any desired direction relative to the grinding wheel 22 as long as it remains in the same plane.

The present fixture includes a support or mounting block 42 which is adapted to be secured to the table 32. The support may be fabricated from several different pieces or it may be machined out of a solid block. The present support includes an elongated base 42 having a plane surface that is adapted to fit onto the top of the table 32. A pair of openings are provided in the opposite ends of the base 42 for receiving one or more fastening means such as the bolts 44. The heads may be disposed in the track or keyway 38. By tightening the bolts 44, the base 42 will be rigidly secured onto the table 32 in a predetermined fixed relationship. Preferably bolt holes are lpositioned so that the base 42 will be substantially parallel to the table 32. Thus, if the table 32 is disposed' parallel to the axis of the grinding wheel 22, the base 42 will also be parallel.

A pair of guide means may be provided upon the base 42 adjacent the opposite ends thereof. Although these guide means may be of any desired variety, in the present instance they are substantially cylindrical passages 43 which extend across the base 42. When the table 32 is parallel to the axis of the grinding wheel 22 the passages 43 will be substantially parallel to the grinding wheel 22.

The fixture 10 lmay also include a platform or carriage 46 which is movably mounted upon the base 42. The present carriage includes a substantially horizontal portion having a plane surface 48 on the top thereof. A pair of

anges

52 and 54 may be provided along the opposite sides of the carriage 46 so as to project downwardly therefrom. r

A pair of substantially cylindrical rods S6 and 58 may be secured to the two

flanges

52 and 54 so as to extend transversely across the carriage 46 and parallel to the top of the carriage 46.

The outside diameters of these

rods

56 and 58 are substantially equal to the inside diameters of the passages 43 on the opposite ends of the base 42. Thus, the

rods

56 and 58 may be slidably disposed within the passages 43 to thereby form a pair of substantially parallel guides which will be effective to permit the carriage 46 to move transversely across the base 42 and the table 32. As a consequence, when the keyway 38 or l[able 32 is positioned parallel to the axis of the grinding wheel 22, the carriage 46 may be made to move across the table 32 substantially parallel to the plane of the grinding wheel 22. As will become apparent subsequently, it is desirable for the carriage 46 to be biased away from the grinding wheel 22. Although this may be accomplished by any desired means, such as pneumatically, etc., in the present instance a pair of springs 60 are provided. One end of each spring 60 is secured to the flange 54 while the other end is secured to the base 42. More particularly, a pair of rods 62may be disposed inside of the springs 60. One end of each rod 62 is secured to the flange 64 on the base 42. The other end of each rod 62 is slidably disposed in openings in the liange 54. 'It may thus be seen that the two springs 60 will resiliently bias the entire carriage 46 transversely of the base 42 in a direction away from the grinding wheel 22.

Suitable work supporting means or a tool holder may be provided on the carriage 46 for carrying the tool 66 to be sharpened. This holder may be of any desired variety. However, in the present instance the holder includes a pair of brackets 68. Each of the brackets 68 includes a base having a substantially plane surface thereon that is adapted to seat upon a plane surface 48 formed by the top of the carriage 46. A track or keyway 70 similar to the keyway 38 may be provided on the top of the carriage 46 for receiving the brackets 68. Thus, fastening means such as a bolt may be provided which will extend into the keyway 70 and secure the brackets 68 in position. Each of the brackets 68 may include an arm which projects upwardly above the carriage 46 in the general direction of the grinding wheel 22. The upper end of each arm may have bearing means 71 for receiving a tail stock 72. Each of the stocks 72 includes a substantially cylindrical shaft 73 having a tapered end 80 that forms a relatively sharp point. Suitable clamps 82 may be provided for locking the two shafts 73 in a ixed axial position or releasing the shafts 73 for axial movement. It may thus be seen that shafts 73 may be separated to permit the workpiece to be positioned therebetween. The shafts 73 may then be moved axially inwardly so as to clamp the workpiece therebetween.

In order to secure the workpiece or tool 66 between the tail stocks 72, a mounting means compatible with the tail stocks 72 and the tool 66 may be provided. In the present instance the tool 66 includes a cylindrical body 74 and a plurality of blades 76 which project outwardly from the body 74. Each of these blades 76 includes a cutting edge that is to be ground to a predetermined contour or profile. A substantially cylindrical passage 78 extends axially through the center of the body 74. This passage 7 8 is a standard size for mounting on the machine that employs the tool 66. When sharpening such a tool 66, a conventional arbor may be provided. Such an arbor includes a substantially cylindrical shaft having a center section that iits into the passage 78 through the tool 66. cured in position thereon. The opposite ends of the shaft include center openings adapted to receive the tapered ends 80 of the two tail stocks 72. Thus, the arbor may be clamped in position between the two stocks 72. Although this is an effective means for mounting the tool 66, it has been found that where there are a large number of tools to be sharpened they frequently have a wide variety of lengths and diameters. As a consequence, it is necessary to stock a correspondingly wide assortment of arbors.

In order to overcome the foregoing diiculty, in the present instance a pair of'adaptor plugs 90 are provided. Each of these plugs includes a substantially cylindrical section 92 and a flanged section 94. The cylindrical section 92 has a diameter that is substantially the same diameter as the passage 78 through the center of the tool 66. As a consequence, this portion may be tted snugly into the center vof the tool 66. The flanged section 94 is adapted to t against the end of the tool 66 when it is properly positioned. The outside of each of the anged sections 94 includes a center hole 96 for receiving the tapered ends 80 of the stocks 72. It will thus be seen that irrespective of the length of the tool 66 one set of these plugs 90 will be effective to provide very precisely located centers on each end of the tool.

In order to control the lateral position of the tool 66 as it moves axially past the grinding wheel 22, suitable control means may be provided. The control means will be effective to move the carriage 46 transversely of the table 32 as the table 32 moves axially. In the present instance this control means includes a template 98 having a profile thereon corresponding to the profile to be ground and a follower 100 that will ride against the edge 102 of the template 98.

To secure the template 98 and follower 100 in position, suitable fastening means 104 and 106 may be provided on the carriage 46 and on the cross slide 24. In the present instance the fastening means 104 on the carriage 46 includes an elongated plate 108 which is disposed on the top surface 48 of the carriage 46. A plurality of bolts The tool 66 is mounted on this section and se- 110 may be provided which are effective to tighten the plate 108 downwardly onto the horizontal surface 48 of the carriage 46.

The fastening means 106 on the cross slide 24 includes a pedestal 112 which may be secured to the cross slide 24 by means of a plurality of bolts 114. The pedestal 112 will project upwardly from the cross slide 24 and move therewith. As a consequence, if the pedestal 112 is initially approximately aligned with the 'grinding wheel 22 it will always remain in this approximate alignment. The upper end of the pedestal 112 is also preferably disposed in substantially the same plane as the surface 48 on the top of the carriage 46. Suitable fastening means 106 are also provided on the top of this pedestal 112. This fastening means 106 may be substantially identical to the fastening means 108 on the top of the carriage 46. This fastening means 106 includes an elongated plate 116 that is secured onto the top of the pedestal 112 by means of a plurality of bolts 118.

The template 98 may be secured in one of the fastening means 104 or 106 while a follower 100 may be secured in the other of the fastening means 106 or 104 so as to engage the edge 102 of the template 98. If the template 98 is secured in the fastening means 104 on the carriage 46 in the manner shown in FIGURE 6A, the template 98A will be a negative template. That is, the profile formed on the edge 102A will be a negative or the complement of the profile which is to be ground onto the cutting edge of the blades 76 on the tool 66. If the template 98B is secured to the fastening means 106 on the top of the pedestal 112 in the manner shown in FIGURE 6B, the template 98B will be a positive template. That is, the profile formed on the edge 102A will be substantially identical to the contour or profile to be ground onto the cutting blades 76 of the tool 66. It may thus be seen from FIGURES 6A and 6B that the same contour may be ground onto the blades 76 by employing either the negative template 98A on the carriage 46 or a positive template 98B on the pedestal 112.

The follower 100 preferably includes a mounting portion 120 that will fit into the fastening means 104 and 106 and a small portion 122 to ride against the edge 102. This portion 122 preferably has a cross section which is substantially identical to the shape of the periphery of the grindingV wheel 22. If the portion 122 of the follower 100 and the grinding wheel 22 have substantially identical shapes, the cam surface on the edge 102 of the template 98 may be a true positive or a true negative of `the profile to be ground onto the cutting tool 66.

It may thus be seen that when the template 98 and the follower 100 are properly mounted in the fastening means 104 and 106, the springs 60 will be effective to bias the carriage 46 away from the grinding wheel 22. This will maintain the cam surface on the template 98 in intimate contact with the'follower 100. As a consequence, when the carriage `46 travels axially so as to move the tool 66 past the grinding wheel 22, the cam surface on the edge 102 of the template 98 will slide against the follower 100 and force the carriage 46 to move transversely of the bed 28. If the cross slide 24 is adjusted so that the grinding wheel 22 will just conta-ct the cutting edge of the `blades 76, the -blades 76 will be `ground into the desired contour.

It may thus be seen that in order to employ the present fixture 10 for grinding the cutting edge on a tool 66, ythe fixture 10 may be mounted upon the table 32 of a substantially conventional grinder 12. The4 ibase 42 is positioned on the table 32 so that the openings in the ibase 42 are aligned with the keyway 38. The bolts 44 are then tightened so as to secure the base 42 on the table 32 substantially parallel thereto. Normally, the table 32 will be adjusted so that the table 32 is substantially parallel kto the axis of the grinder. However, under some circumstances it 4may be desir-able for the table 2 to be adjusted at some predetermined angle as indicated bythe protractor 40. Following this, the two arbor plugs may be inserted into the ends of the passage 78 through the tool 66. The tool 66 is then placed between the two tail stocks 72 and the stocks 72 adjusted until the ends` 80 thereof are positioned in the center holes 96. The stocks 72 are then tightened so that the tool 66 will tbe rigidly retained therebetween. The tool 66, however, will be free to rotate about its own axis.

The template 98 and the follower 100 may also be secured in position. If a negative template 98A (i.e., a template contoured to correspond to a. negative of the profile -to tbe ground on the tool) is employed, the template 98A is clamped into position upon .the carriage 46 by the fastening means 104. At the same time, the follower 100 is clamped into position by the fastening means 106 on the pedestal 112. If a positive template (i.e., a template having a profile that is identical to the prole to be ground) is to 'be employed, the template 98B is clamped in position by the fastening means 106 on the pedestal 112 and the follower 100 is clamped in position by the fastening mean-s 104 on the carriage 46. The springs 60 will then 'be effective to bias the entire carriage 46 -away from the grinding Wheel 22 so as to maintain the edge of the template 98 against the surface of the follower 100.

To assist in positioning the blades '76 on the tool 66, a tool res-t is mounted on the support 16 so as to extend along the periphery of the grinding wheel 22. The tool rest 130 may then be adjusted so that the lower end 132 thereof will engage the tooth or blade 76 immediately adjacent the periphery of the grinding wheel 22. The height of the tool rest 130 is preferably set so that a plane 134, including the cutting edge of the blade 76,

will be substantially parallel to the plane 136 of the template 98 and the plane in which it will travel. In the present instance both of these

planes

134 and 136 are then grasp the tool 66 so as to retain one of the teeth or blades 76 against the end 132 of the tooth rest 130. The

bed 28 is then moved axially so as to cause the entire fixture 10 to move axially. This will cause the tool 66 carried thereby to move past the grinding wheel 22 in a direction substantially parallel to the axis of the grinding wheel 22. As this motion progresses, Ithe springs 60 will bias the carriage 46 away from the grinding wheel 22 and retain the template 98 and follower 100 in intimate--contact with each other. As a consequence, as the carriage 46 is moved axially, the template 98 will 'be effective to cause ythe 'carriage 46 to follow a path corresponding to the shape of the profile that it is desired to grind. This process may be repeated .for each of the blades 76 on the tool 66. The hand wheel 26 may Ibe intermittently adjusted so as to advance the cross slide 24 Itoward the grinding wheel 22 whereby each successive pass of the tool 66 will grind a little more from the V cutting edges of the blades 76 until finally all of the blades 76 have been properly ground to the required contour.

While only a limited number of embodiments of the present invention are described and disclosed herein, it `will be readily apparent lto persons skilled -in the art that numerous changes and modifications may be made thereto without departing from the spirit of the invention. Accordingly, the foregoing disclosure and description thereof are for illustrative purposes only and do not in any way limit the invention which is defined only by the claims which follow.

What is claimed is:

1. A grinding machine of the class described for grinding the cutting edges of the blades of a tool into a predetermined profile, said machine including the combination of:

a grinding wheel having an axis of rotation,

a cross slide for moving in transverse directions parallel to a plane perpendicular to the axis of rotation of said wheel,

a bed carried by said cross slide and movable thereon in longitudinal directions parallel to the axis of rotation of said grinding wheel,

a table mounted on said bed for moving therewith in transverse and longitudinal directions,

a carriage,

means Vfor mounting said carriage on said table for moving therewith, said means being effective to permit said carriage to only move in a direction parallel to the plane perpendicular to the axis of rotation of said wheel,

a pair of aligned tool supports mounted on said carriage for moving therewith, said supports being effective to position the cutting edges of said blades against the periphery of said grinding wheel for be- -ing ground thereby,

-a tooth rest mounted in a fixed position for engaging one of the blades of said tool immediately adjacent the point of contact between said grinding wheel and said blade,

first fastening means disposed on said carriage, said fastening means being movable with said tool,

second fastening means disposed on said cross slide and movable with said cross slide only in directions parallel to a plane perpendicular to the axis of rotation of said grinding wheel,

a plane template disposed in one of said fastening means and having an edge with a shape corresponding to the surface to be ground on the blade, the plane of said template being disposed substantially parallel to the plane in which said tool moves past said grinding wheel,

a follower mounted on the other of said fastening means for engaging said edge of said template, and

means for biasing said carriage away from said grinding wheel to thereby maintain said edge of said template against said follower to thereby control the transverse position of said tool as said table moves longitudinally.

2. In a grinder having a grinding wheel and a table movable relative to the grinding wheel and in any direction within a plane which extends parallel to the axis of rotation of the' grinding wheel, a fixture comprising:

a base support for being secured to said table in a predeterminable fixed position thereon for moving together with the table;

a carriage movably mounted on said support for being carried by said support upon movement of the table, said carriage being movable relative to said support in either one of two oppositely oriented directions, said base support having a position on the table relative the grinding wheel so that said carriage as movable relative to said support is movable towards or away from the grinding wheel;

a workpiece support mounted on said carriage for moving therewith, said workpiece support being .effective to position a surface of a workpiece against the grinding wheel;

first fastening means on the carriage moving therewith;

second fastening means mounted to follow the movement of the table in a direction toward and against the grinding wheel, one of said fastening means being adapted for carrying a template having a profile corresponding to the shape of the surface to be ground onto the workpiece when positioned by said workpiece support, the other one of said fastening means being adapted to carry a follower; and

means interconnecting said carriage and said support for resiliently biasing said carriage in a direction away from said grinding wheel thereby urging the template against the follower so that upon movement of the table in a direction parallel to said axis of rotation the carriage will be moved relative to said base support as determined by the profile of said template.

3. In a grinder having a grinding wheel and a table movable relative to the grinding wheel in any direction within a plane which extends parallel to the axis of rotation of the grinding wheel, a fixture comprising:

a base support for being `secured to said table in a predeterminable xed position thereon for moving with the table;

slide ways on said base support extending thereon in a first direction which is parallel to said plane of permissible movement of said table;

slides disposed in each slide ways for moving in said first direction as well as oppositely thereto;

a carriage mounted on said slides for moving therewith;

a pair of tail stocks mounted on said carriage for moving with said carriage, said' tail stocks being aligned with each other and effective to carry a workpiece so as to position a surface thereof against the grinding wheel;

first fastening means for being releasably mounted on a predetermined portion of said grinder permitting movement towards and away from the grinding wheel;

second fastening means on saidcarriage for moving therewith one of said fastening means being adapted to carry a template having a profile corresponding to the shape of the surface to be ground onto said workpiece, the other of said fastening means being adapted to carry a follower for coacting with said profile; and

spring means on said base support and said carriage for resiliently biasing said carriage in said first direction so as to maintain the follower and profile in engagement with each other, to provide relative motion of said tail stocks on said carriage in said first direction and oppositely thereto upon movement of the table in the plane of permissible movement and in dependence upon'the profile of the template.

4. A grinding machine of the class described for grinding a profile onto the cutting surfaces of a tool having a mounting passage extending axially through the center thereof and a plurality of blades on the outside thereof, said machine including the combination of a grinding wheel having an axis of rotation;

a table mounted adjacent said grinding wheel for rnoving in a plane parallel to said axis of said wheel and in directions parallel to and normal to said axis;

a carriage;

means for mounting said carriage on said table to move relative to said table and in directions towards and away from said wheel;

a pair of mounting plugs having substantially cylindrical portions that slidably fit into said passage, each of said plugs having a centering opening disposed on an axis of said cylindrical portions;

a pair of aligned tail stocks yon said carriage, the ends of said stocks being disposed in said centering openings and being effective to position the cutting surfaces of said tool against the periphery of said grinding wheel first flastening means on the carriage moving therewit second fastening means mounted to follow the movement of the table in a direction toward and against the grinding wheel, one of said fastening means being adapted for carrying a template having a profile corresponding to the shape of the surface to be ground onto the workpiece positioned by said workpiece support, the other one of said fastening means being adapted to carry a follower; and

resilient means biasing said carriage relative to said table in said direction of relative carriage movement away from said wheel, thereby urging said follower against the profile of said template so that as the table moves in a direction parallel to said axis of rotation the carriage will be moved relative to said table support as determined by the profile of said template.

References Cited by the Examiner UNITED STATES PATENTS Gardner 82-44 Barrow.

Virdin 51-100 Warner et al 51-100 Robbins 51-l00 Pioch et al 51-237 French 51-225 X LESTER M. SWINGLE, Primary Examiner.

Claims

2. IN A GRINDER HAVING A GRINDING WHEEL AND A TABLE MOVABLE RELATIVE TO THE GRINDING WHEEL AND IN ANY DIRECTION WITHIN A PLANE WHICH EXTENDS PARALLEL TO THE AXIS OF ROTATION OF THE GRINDING WHEEL, A FIXTURE COMPRISING: A BASE SUPPORT FOR BEING SECURED TO SAID TABLE IN A PREDETERMINABLE FIXED POSITION THEREON FOR MOVING TOGETHER WITH THE TABLE; A CARRIAGE MOVABLY MOUNTED ON SAID SUPPORT FOR BEING CARRIED BY SAID SUPPORT UPON MOVEMENT OF THE TABLE, SAID CARRIAGE BEING MOVABLE RELATIVE TO SAID SUPPORT IN EITHER ONE OF TWO OPPOSITELY ORIENTED DIRECTIONS, SAID BASE SUPPORT HAVING A POSITION ON THE TABLE RELATIVE THE GRINDING WHEEL SO THAT SAID CARRIAGE AS MOVABLE RELATIVE TO SAID SUPPORT IS MOVABLE TOWARDS OR AWAY FROM THE GRINDING WHEEL; A WORKPIECE SUPPORT MOUNTED ON SAID CARRIAGE FOR MOVING THEREWITH, SAID WORKPIECE SUPPORT BEING EFFECTIVE TO POSITION A SURFACE OF A WORKPIECE AGAINST THE GRINDING WHEEL; FIRST FASTENING MEANS ON THE CARRIAGE MOVING THEREWITH; SECOND FASTENING MEANS MOUNTED TO FOLLOW THE MOVEMENT OF THE TABLE IN A DIRECTION TOWARD AND AGAINST THE GRINDING WHEEL, ONE OF SAID FASTENING MEANS BEING ADAPTED FOR CARRYING A TEMPLATE HAVING A PROFILE CORRESPONDING TO THE SHAPE OF THE SURFACE TO BE GROUND ONTO THE WORKPIECE WHEN POSITIONED BY SAID WORKPIECE SUPPORT, THE OTHER ONE OF SAID FASTENING MEANS BEING ADAPTED TO CARRY A FOLLOWER; AND MEANS INTERCONNECTING SAID CARRIAGE AND SAID SUPPORT FOR RESILIENTLY BIASING SAID CARRIAGE IN A DIRECTION AWAY FROM SAID GRINDING WHEEL THEREBY URGING THE TEMPLATE AGAINST THE FOLLOWER SO THAT UPON MOVEMENT OF THE TABLE IN A DIRECTION PARALLEL TO SAID AXIS OF ROTATION THE CARRIAGE WILL BE MOVED RELATIVE TO SAID BASE SUPPORT AS DETERMINED BY THE PROFILE OF SAID TEMPLATE.