US2958167A - Grinder fixture - Google Patents

Description

Nov. 1, 1960 A. E. MUELLER GRINDER FIXTURE 3 Sheets-Sheet 1 Filed May 9, 1958 Q mm \w Jmm 1N VEN TOR. JAV/A/ E. MUELLEI? A. E. MUELLER GRINDER FIXTURE Nov. 1, 1960 3 Sheets-Sheet 2 Filed May 9, 1958 wa n Wm MY.

INVENTOR. 44 V//\/ 5. M05445? a .UQQWQ a w Q. m ,m i

Nov. 1, 1960 A. E. MUELLER 2,958,167

GRINDER FIXTURE Filed May 9, 1958 s Sheets-Sheet :5

INVENTOR. AL V/A/ E. MUEL LE1? ATTwQA/EK GDER FIXTURE Alvin E. Mueller, Downey, Calif., assignor of one-half to Seth Silver-man, Los Angeles, and one-half to Sydney Dock, Glendale, (Calif.

Filed May 9, 1958, Ser. No. 734,320

12 Qlainis. (Cl. 51-232) This invention relates to a grinding fixture such as employed to hold a tool, the point of which is to be applied to a grinding tool or the like.

The point of the tool is usually provided with a conical face which is broken through by relief recesses spaced equidistant apart around the periphery of the tool.

Such a fixture is usually provided with means for shifting the holder for the tool along its longitudinal axis so as to withdraw it from the face of the grinder when the recesses are passing the location of the grinding face and to apply the helical edges of the conical faces of the tool to the grinder face while the tool is being rotated on its axis. A principal object of this invention is to provide improved cam means for effecting these shifting movements along the axis of rotation of the tool.

Another object of the invention is to provide a cam employed with a solid body, of arc form movably mounted, and provided with means for adjusting the camwith respect to the axis of the tool so that the conical working face of the cam when displaced into different positions of adjustment, will effect a change in the amount of movement that occurs when the cam effects the shifting of the tool longitudinally on its axis.

Another object of the invention is to provide improved cam follower means to cooperate with the working face of the cam, and including pins as contact means, which pins may be of a number to correspond with the number of relief recesses that are on the tool thatis to be ground. For example, two, three or even four relief arcuate faces and four flutes.

While the accompanying drawing and thedescription in this specification are .concernedprincipally with the 'point of a tool that is to beground, it should be understood that the invention is also applicable where the face or faces on the tool that are to be ground are not necessarily located at the point of the tool; and itshould be understood that the movement effected by the functioning of the cam is preferably supplemented by a spring that is compressed by the movementeffected .by the cam and operates as a return spring to give the tool being ground the reciprocating movement which it should have.

While this invention is concernedpri-ncipally with the form and manner of adjustmentof the cam itself, the invention as described herein is concerned also with the novel features of the follower pins that run on the wor ing face of the cam.

Further objects of the invention will be evident from a careful reading of the present specification .and study of the drawing accompanying the same.

The invention resides in the novel parts and combination of parts, all of which cooperate to produce an efficient grinding fixture.

A preferred embodiment of the invention is described in the following specification while the broad scope of the invention is pointed out in the appended claims.

In the drawing:

Figure l is a longitudinal vertical section taken through mm o the casing of the grinder showing the tubular spindle partly in section andpartly-in elevation, and also showing a boring tool having a conical tip illustrated as being applied to the face of a grinder wheel. In this view the upper portion of the casing is broken away to show it in section, while the base portion of the casing is shown in side elevation.

Figure 1a is a fragmentary view and is a section taken in a radial plane through the axis of the spindle of the fixture shown in Figure 1. This view illustrates in detail the means employed for securing the cam fol-lower collar to the sleeve that surrounds the spindle.

Figure lb is a horizontal section on the line 1b1b of Figure 1.

Figure 2 is a vertical section taken onthe line 22 of Figure l, and further illustrating the cam of my invention, and its mounting that enables it to be cocked into different positions to vary, and regulate, the length of the shifting movement that the cam imparts to the sleeve and spindle while being rotated.

Figure3 is a vertical cross section taken on the line 33 of Figure 1, and particularly illustrating a connection between the casing and the spindle that enables the casingyand spindle to be non-rotatably connected together-or'free of each other when desired.

Figure 4 is a front elevation of the cam and showing it in an extremely cocked position and also indicating the path of the contact pin or pins that may be along the cam when in this position.

Figure 4a is a detail end viewof the right end of the cam and showing an adjacent portion of the body of the cam broken away.

Figure 5 is a perspective of one of the follower pins that run on the working face of the cam.

Figures 6, 7, and 8 are perspectives which show, respectively, the annular pin .carrier with pins which may be four in number as in Figure 6, or three in number as in Figure 7, or two in number as in Figure 8, and showing the equidistant spacing of all of the pins in these views.

Figures 9, 10 and 11 are diagrammatic views that illustrate in this manner the reciprocating movements of the tool carrier elements and where these movements occur in a single cycle of rotation of the tool being ground.

Figure 12 is a fragmentary view broken away to show a modified form.

Figure 13 is a vertical section on the line 13-13 of Figure 12.

In practicing the invention we provide a fixture casing 1 that is illustrated as having an indexing hub 2, which is mounted to rotate on an indexing base 3, which is mounted on an anchoring base 4 having oppositelydisposed bifurcated lugs 5, on which bolts and nuts are attached to clamp the fixture on a working face plate at a point near a rotating grinder having a grinder face .6 in proximity to the fixture which may carry a tool 7 with a drilling end 8, for example, a plurality of conical faces 9 with cutting edges 10 spaced equidistantly from each other, and separated by relief flutes 11.

In this view the direction of rotation of the toolin driving it and its direction of rotation when at work is indicated by the arrow 12.

The tool illustrated has a shank 13 which is shown as clamped between jaws of a collet 15, which is of tubular form and provided with three slots such as the slots 1-6 that extend a considerable distance throughout the length of the collet.

The inner end of the collet is provided with. screw threads 17 by means of which it is attached to the forward end of a tubular spindle 18'. The thread 17 of the ,p p r V 3 l spindle" engages thread in a counterbore at 19, so that an annular shoulder 20 is formed near which the end of the collet may approach but not seat upon.

I However, .When the inner end of the collet has proper clearance at the annular shoulder 20 a conical counterbore 21 on the forward end of a sleeve 22 enables contacting inclined conical faces of the jaws,14 to clamp the shank 13 of the tool securely between the jaws by rotating thebore wheel 27.

This sleeve 22 encompasses the tubular spindle 18 with its rear end 23 located near the rear end of the casing 1. .The tip of this extension 23 has a conical 'counterbore 24, which operates as a seat 25 for a conition.

With the construction described, it will be evident that if the sleeve 22 is held against rotation, then rotation of the spindle 18, by means of the hand wheel can be made to draw the collet further into the forward end by reason of the presence of the thread 17 already described.

This operation enables the tapered seat 2'4 and the conical countcrbore 21 at the forward end of the fixture to cooperate to clamp the shank 13 of the tool by means of the jaws at the forward end of the collet. In Figure 1 I illustrate means shown in section in Figure l and also in section in Figure 3. This means preferably includes a pin 30 and this pin is rigid with a head 31 on its outer end, but slides freely through a drilled hole in a hexagon nut 32, or the like which has a threaded nipple 33 that can be screwed into a threaded socket 34 so as to seat the face of the nut 32 on a small horizontal face or pad 35 on the upper side of the casing 1.

The lower end of the pin 30 is secured to a tip 36 the upper face of which operates as a seat for a coiled spring 37 that thrusts on its upper end against the lower end of the nipple 33, so as to bias the tip 36 towards the sleeve 22. In Figure 1 the pin 30 is shown in its locking position in which it is depressed sufliciently to enable its extreme end in the form of a button 38 to project into a slot 39 which extends longitudinally through the material of the sleeve and parallel with the axis of the spindle.

When desired, however, the pin head 31 can be pulled upwardly and rotated on its axis through ninety degrees. This enables two diametrically opposite abutments 40 which are tapered to edges 41 to seat themselves on the upper end face 42 of the nut 32. When in this position the button 38 will be held clear of the slot 39 and this, of course, will enable the spindle 18 with the sleeve 22 tight on it to be rotated freely by the operator of the fixture by means of the handle 29.

Of course, this is the relation of the parts while the operator of the fixture is conducting a grinding operation.

In this connection it should be understood that the face 6a of the grinding wheel is disposed at an angle to the axis of the tool 7 so that when the tool approaches the grinding wheel to apply one of its conical faces 9 to the face of the grinder, the elements of the conical face as they pass the face 6a will be parallel to it. In other words, when the conical faces are against the grinder face they will be tangent to its periphery.

The forward end of the sleeve 22 projects a considerable distance from the forward end of the casing 1, and this part of the sleeve is provided with an annular shoulder 43; and against this shoulder abuts the rear face 44 of a cam follower comprising a collar 45. This collar carries an extension or extensions to run on a cam 46 that is attached to a face 47 that is recessed back into the forward end of the casing. This cam presents a conical face 48 on which the extension part or parts on the collar run when the spindle is rotating beneath the extension part moving around with it.

In the present instance I provide 2, 3, or 4 contact pins 49, the shanks of which have flat faces 50 engaged by the tips of the set screws 51, that clamp the different pins 49, but before the set screws 51 are tightened up other set screws 52 threaded into the forward faces of the collar 45' are adjusted up far enough to have the tips of the pins just touching the face of the cam.

The projecting ends of the pins are formed with inclined flat side faces 53 so that the extreme end of each pin resembles a chisel edge; that is to say, each pin, as indicated in Figure 5, presents an edge 54- at which the fiat side faces 53 form an acute dihedral angle.

However, this edge 54 has a pitch of proper degree to enable it to abut closely to the face of the cam now about to be described.

Referring now particularly to Figures 1, 2, .and 4, it will be evident from these views that this cam 55 is of arcuate form and mounted for adjustment about the was of a pivotal socket 56 which has a drilled hole extending in through the face 47. In practice I prefer to provide a wrist pin 57, the forward end of which has a threaded stud 53 which is screwed tight into a threaded socket 59 in the rear face of the cam; and just above the cam the casing '1 projects forwardly and overhangs the cam,

forming a visor 60, which functions to provide a mountthe pins 49 in tracking around on the inclined forward face 55a of the cam will be passed in an are along a medial line midway between the inner and outer edges of the cam face 55:: and consequently, the cam will not shift the pins, nor the spindle forward.

However, if the set screws 61 and 62 are adjusted to place the cam in a cocked position, with one end of the cam nearer to the path of the pins 49, and its other end further from their path, such as indicated in the dotted lines 55b (see Figure 2), then as the pins 49 pass upwardly at the right they will be near the inner edge of the cam, but as they leave the carns face, they will be quite near the outer edge of the cam. Hence, as the cam is thicker at its outer edge, each pin that passes in this way will be shifted by the cam toward the left, as viewed in Figure 1, and this, of course, will cause the tool to approach and contact the face 6a of the grinder. The line 550 shows the path of the pins in the cocked cam.

The cam extends through more than degrees of arc, and this arc should be slightly greater than 180 degrees, and at least sufficiently long to insure that even with two pins only on the cam follower, before any pin leaves the face of the cam another pin will have landed on the driving face of the cam.

As the spindle shifts forwardly, means provided on the fixture that is biasing the spindle and sleeve 22 toward the rear operates to return the spindle and of course, the tool 7, to the position it had when the controlling pin 49 encountered the driving face of the cam as it was revolving past it. In the present instance, in order to accomplish this the rear end of the casing is provided with a counterbore 63 .that houses coil spring 64, the rear end of which thrusts against a bushing 65 that is adjustably mounted on the projecting rear end 23 of the sleeve 22, which can be attached and secured in any desired position by means of a set screw 66.

Referring again to the collar 45, of the cam follower, the means employed to secure the same against the shoulder 43 will now be described. Referring particularly to Figure la in connection with Figure 1; on the latter figure a V-type groove 67 is provided encircling the forward end of the sleeve 22 close to the shoulder 43, and at two opposite points on the collar 45 two set screws ahead-"e7 such as the set screws 68 are provided. These set screws have conical tips turned at a smaller angle at their tips than the angle at which the V-shape groove 67 is cut. These pins are located so that when tightened up they will land in the cut on the face 69a of the same, that is remote from the shoulder, thereby forcing the inner face of the collar up against the shoulder.

Referring again to the wrist pin 57, (Figure 1), a similar V.-shape groove 69 extends around the waist of the wrist pin 57 to receive a conical tip on the set screw 70 that is seated in the tapped hole 71 extending down through the top side of the casing at this point. This set screw should be tight enough in the groove to hold the rear face of the cam seated up against the vertical forward face 47 of the casing 1.

In Figures 12 and 13 there is illustrated means associated with a cam 55a which enables the cam to be shifted by a movement of translation so as to displace the cam bodily from its neutral position. When displaced in this way the cam is displaced from its neutral position and is then out of line with the axis 72, about which the cam follower rotates.

Such a displacement by a movement of translation may be, of course, effected in a verticalor a horizontal position, but in Figures 12 and 13 the means indicated for effecting the displacement operates to displace the cam by a movement of translation in a horizontal direction, as that is more adaptable to the fixture illustrated in Figures 1 and 2.

In order to accomplish this the visor 60a, as shown in Figure 12, at one end is slightly modified from the visor form shown in Figure 2. This is done so that it will present a relatively long vertical end face 73, through which a stem 74 passes in a horizontal direction. In order to accomplish this two drilled holes 75 and 76 are formed through the vertical face 73, and also through a similar vertical face 77 at the other end of the visor. These drilled holes operate as bearings for the stem 74.

In line with the two bores 74 and 76 a tapped drilled hole 78 is formed through the material at the crown 79 of the cam 55a, that is to say, at the middle point of the arc of the cam. This drilled hole 78 is of slightly larger diameter than the drilled holes 74 and 76 so that when this drilled here is tapped, a thread cut into its wall can cooperate with upset thread 70 on the middle portion of the stem 75. The ends of the stem 74, of course, have their bearings in the material at the ends of the visor 60a.

In order to facilitate drilling the relatively larger bore 78 where it is located I prefer to rout out two recesses 80 and 81 equidistant from the middle point of the arc of the cam 55a, in order to have the cam present two vertical faces 82 which will facilitate starting the drill of this bore 78.

When the stem 74 is passed in through the drilled hole 75 from the left, as viewed in Figure 12 and also passed through the oversize opening 78 of the .cam until the upset thread engages the threads cut into the slightly oversized drilled hole; the stem 74 is then rotated to bring the upset thread into the thread of the oversized opening, while guiding the tip of the stem into its bearing opening 7 6.

A collar 83 is then screwed onto a threaded reduced tip 74a and tightened up against a split spring washer 84 thatseats on the annular shoulder at 84a located at the root of the reduced tip 74a. The washer 84 seats against the end face 77 of the visor 60a.

At the other end of the stem 74 an indexing head 85 is provided having a hub 86 with a dowel 87 let into the face 73 to keep the indexingheadproperly aligned.

On the end of the stem 74 a knurled knob 8'8 is.'car ried, having a scribe'line 89 that cooperates with a scale on the indexing head 85, when adjustments are being effected on the cam 55a.

part of the spindle.

-In connection with Figure 13 it should be noted that the flat rear face of the cam 55a is'constantly :held pressedupon the vertical face 91 at the forward end of the casing 92 of the 'fixture "by the'pressure exerted by the cam follower pins; and it should be remembered that there' is always one or more of the cam follower pins 93 running across the working face 94 of the cam.

With the degree of adjustment of the 'cam indicated in 'Figure 12, the. cam follower pins 93 will describe a path about as indicated by the broken line 95.

This fixture is provided with means that can be employed to shift the spindle with the sleeve 22 tightened on it by means already described herein above.

It may be desired occasionally to effect a forward shifting of the cam follower to remove it sufficiently to enable the spindle and sleeve to be rotated by the handwheel, or other means, freely and eliminating the normal functioning of the cam follower and the cam.

In other words, such a transformation in the mode of operation could'be used to permit a tool to be held in the collet and rotated freely on its axis as though mounted in a'lathe chuck.

In order to accomplish this the sleeve 22, should be tightened on the spindle; then it becomes virtually a The .outer surface of the sleeve has been previously provided with a circumferential slot 96 (see Figures 1 and 111). And the casing 1 on its right side and at the level of its horizontal axis is provided with a set screw97 located a short distance forward of the circumferential groove 96.

'compressingthe spring 64, and finally aligning the groove 86 with a reduced'tip 103 at the forwardend of the setscrew97; while being held in this relation the set-screw is rotated to advance the tip 103 into the groove 96, and in this positionthe cam follower collar 45 and its follower'pins 49 can he held clear of the cam 46 to permit free rotation 'of the cam follower without any interference from the cam .as the same cam follower rotates.

Many other embodiments of this invention maybe resorted to without departing'from the spirit of the invention I claim as my invention, and desire to secure by Letters Patent:

1. In a grinder fixture for holding and applying a tool to be ground, to the abrasive face of a grinder, the com bination of a casing, a chuck for clamping the tool with its axis coinciding with the axis of the chuck, a spindle rotatably mounted in the casing, and carrying the chuck, a cam having a conical driving face, means for supporting the cam so that the said conical driving face is coaxial with the axis of revolution of the spindle, means for supporting said spindle so that it is shiftable along its own axis, a cam follower secured to rotate in unison with the spindle, and having a contact part capable of engaging said conical driving face along a contact path coinciding with the medial arcuate line of said driving face, and approximately in a plane making approximately a right angle with the geometrical central axis of the cam, and means for effecting an adjustment of said cam into a laterally displaced position in a plane extending transversely to the axis of rotation of the spindle and the tool, and thereby causing the said contact part to engage the driving face of the cam along a' new path lying approximately-in a plane that deviates from the approximate plane in which said medial line lies, and thereby altering the length of travel of the tool toward and from the abrasive face of the grinder an amount approximately proportionate to the degree of said adjustment.

against said driving face of said cam.

3. A grinding fixture for holding and applying a tool to be ground, to the abrasive face of a grinder, according to claim 1, in which the displaced positions for the cam with respect to the axis of the rotation of the tool includes means for effecting 'the adjustment of the cam about a pivotal support on the geometric axis of the face of the cam, thereby displacing the cam into a cocked position about said axis.

4. In a grinder fixture for holding and applying a tool to be ground to the face of a grinder, according to claim 1, in which the said cam is of block-form and mounted for rotation on a pivot to facilitate its adjustment into the cocked position.

5. In a grinder fixture for holding and applying a tool to be ground to a grinder face, according to claim 1, including a tubular sleeve coaxial with the spindle and surrounding the same, and in which the chuck comprises a collet having a thread connection at the forward end portion of the spindle, said collet having spaced apart jaws at its forward end having inclined circumferential faces on the jaws; the forward end of said sleeve having a tapered counter-bore in which the tapered faces of said jaws seat, the rear end of said spindle and the rear end of said sleeve having abutting faces cooperating as a seat for the rear portion of the spindle, said sleeve having a longitudinal slot in' the outer face thereof, and spring- '-loaded detent pin means with a tip biased by the spring toward the sleeve for tightening the collet and locking the sleeve against rotation within the casing, an actuating part rigid with the spindle at the rear end of the casing for rotating the spindle, said detent-pin means tip operating when in the said slot, to enable the rotation of the manually operated part to loosen the collet in the sleeve;

said detent-pint means having means functioning upon rotation of the same to hold its tip withdrawn from the slot.

6. A grinding fixture for holding and applying a tool to be ground, to the abrasive face of a grinder, according to claim 1, in which the means for adjusting the cam into different displaced positions with respect to the axis of rotation of the tool consists of means for shifting the cam laterally by a movement of translation with respect to the axis of rotation of the contact part.

7. A grinder fixture according to claim 1, in which the cam follower includes a cam body and said contact part comprises a pin secured to the camrbody and projecting toward the plane in which said driving face lies, said pin having a chisel-form tip presenting an edge lying in a plane extending about radially to the axis of rotation of the cam body.

8. In a grinder fixture for holding and applying a tool to be ground, to the face of a grinder, the combination of acasing, a chuck for clamping the tool, a spindle rtatably mounted in the casing, and carrying the chuck, a cam having a conical driving face, means for supporting the cam so that the conical driving face is coaxial with the axis of revolution of the spindle, means for supporting said spindle so that it is shiftable along its own axis, a cam follower secured to rotate in unison with the spindle, and having a contact part capable of engaging said conical driving face and contacting the same along an arc, and means for adjusting said cam into a cocked position in which the axis of the conical driving face is eccentric to the axis of rotation of the spindle, whereby the said contact part engages the said driving face along a line inclined with respect to the transverse plane in which said driving face lies, thereby effecting the shifting -movement of said spindle and said tool with respect to the grinder face.

it is 'shiftable' along its cam axis, a cam follower secured to rotate in unisonwith the spindle, and having a contact part capable of engaging said arcuate driving face and contacting the same along an arc, and means for adjusting said cam into a cocked position in which the axis of'the conical driving face is eccentric to the axis of IO- tation of the spindle, whereby the said contact part engages the said driving face along a line inclined 'with'respect to the transverse plane in which said drivingfa'ce turns, thereby effecting the shifting movement of said spindle and said tool with respect to the grinder face.

10. A grinder fixture according to claim 9, in which the said contact part is a pin, and in which the cam body and the pin have cooperating means for preventing rotation of the pin on its own axis, thereby maintaining the said edge in its radial plane with respect to the axis of the cam body. a

ll. In a grinder fixture for holding and applying a tool to be ground, 'to the face of a grinder, the combination of a casing, a chuck for clamping the tool, a spindle rotatably mounted in the casing, and carrying the chuck, a cam having a conical driving face, means for supporting the cam so that the conical driving face is coaxial with the axis of revolution of the spindle, means for supporting said spindle so that it is shiftable along its own axis, a cam follower secured to rotate in unison with the spindle, and having a contact part capable of engaging said conical driving face and contacting the same along an arc, and means for adjusting said cam into a cocked position in which the axis of the conical driving face is eccentric to the axis of rotation of the spindle, whereby the'said contact part engages the said driving face along a line inc-lined with respect to the transverse plane in which said driving face lies, thereby effecting the shifting movement of said spindle and said tool with respect to the grinder face.

12. In a grinder fixture for holding and applying a tool to be ground to the face of a grinder, the combination of a casing, a chuck for clamping the tool, a spindle rotatably mounted in the casing, and carrying the chuck, a cam having an arcuate driving face inclined with respect to the plane of rotation of the cam follower, means for supporting the cam so that the said driving face is coaxial with the axis of revolution of the spindle, means for supporting the said spindle so that it is shiftable along its own axis, a cam follower secured to rotate in unison with the spindle, and having a contact part capable of engaging said arcuate driving face and contacting the same along an arc, and means for adjusting said carn into a cocked position in which the axis of the conical driving face is eccentric to the axis of rotation of the spindle, whereby the said contact part engages the said driving face along a line inclined with respect to the transverse plane in which said driving face turns, thereby eifecting the shifting movement of said spindle and said tool with respect to the grinder face.

References Cited in the file of this patent UNITED STATES PATENTS 1,981,174 Hille Nov. 20, 1934 2,004,283 Hurt June 11, 1935 2,196,416 Jacob Apr. 9, 1940 I 2,249,656 Huband July 15,1941 2,325,364 Boeniug .a July 27, 1943

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