US2373882A - Abrasive wheel dressing machine - Google Patents

Description

April 17-, 1945. G'. F. EGLINTON ABRASIVE WHEL DRESSING MACHINE 'Filed Nov. 3, '1943 5 sheets-sheetl April 17, 1945. G. F, EGLINTON ABRAsIvE wHEEL DREssI NG' MACHINE Filed Nov. 3, 1943 5 Sheets-Sheet 2 INVENTOR April 17, 1945.

G. F. EGLINToN ABRASIVE WHEEL DRESSING MACHINE Filed Nov. 3, 1943 5 Sheets-Sheet 3 INVENTOR Geo/:ge 7722221120. BY Z ATTORNE YS.

April 17, 1945 G. F. EGLINTON 2,373,ss2 V ABRAS IVE WHEEL DRESSING MACHINE AFiled Nov. :5, 1943 5 sheets-snet 5.

ATTORNEYS.

Patented Apr. l7, 1945 George F. Eglinton, Detroit, Mich assignor, by mesne assignments, to Lincoln Park Industries, Inc., Lincoln Park,. Mich., a corporation of Michigan Application November 3, 19 43, Serial No. 508,784

' 11 oiaims. (cl. si-ss) The present invention relates toan abra'sivel wheel dressing machine for forming, dressing or truing the operative faces of grinding wheels used in form grinding and particularly to such a grinder adapted for the grinding orltruing within close precision limits of an abrasive wheel utillzed-in grinding high precision forms in a work piece.

In the particular embodiinent herein disclosed the grinder is employed to dress the grinding edge vof an abrasive wheel wutilized rin the precision grinding of British standard threads on a thread gauge. In such use, it is essential that the shape and dimensions of the grinding wheel be maintained to the desired shape within close precision limits. This is accomplishedby. first dressing the grinding surface of the grinding wheel to the desired shape and thereafter .by truing operations thereon to maintain its desired working form. In the instance just mentioned, a diamond impregnated abrasive' wheel is' employed as the Igrinding wheel to grind the desired thread form into the body of the gauge member which is .formed of a hard wear resisting material such,

for example, as tungs'ten carbide. The grindins wheel edge is dressed to provide angularly inclined cutting faces thereon which Join each other in a small radius to form an arcuate circumferential edge on said wheel. When such a wheel is employed for grinding the body of the gauge, the thread form which results from its use has inclined side portions ioined'in an arcuate bottom portion corresponding to the shape of -the dressed or trued grinding surfaces of the grinding wheel.

It is anobject of the present invention to provide an abrasive wheel dressing machine char-i acterized particularly by its accuracy in operation, its relative lsimplicity. of structure and design and its ready adaptability to the grinding or truing of abraslve wheels having different shaped grinding edges, and bymeans of which 'the shaped grinding edge is' uniformly dressed or trued to a desired form within close limits. v V

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this. specification wherein like reference characters designate corresponding parts in the several views.

In the drawings: v

precision on the line l-l of Fig. 2

erative position for dressing a diamond impregnated abrasive grinding wheel.

Fig. 2 is a top plan of the shown in Fig. 1. 4

Fig. 3 is a side elevation with parts broken away of the machine shown in Fig. 1.

Fig. 4 is a sectional view taken substantially looking in the direction of the arrows.

Fig. 5 is an elevation taken substantially'along the line 5-'5 of Fig. 3 looking in the direction I of the arrows.

Fig. 6 is a view similar to Fig. 2 but showing vin addition to the dressing of the one inclined face of the grinding wheel the dressing of Vthe opposite inclined edge of the grinding wheel when the parts are moved to' the position shown in the dotted'line portions of this view..

Fig. 7 'is an enlarged simplifiedview showing the position of the dressing wheel during the dressing of the grinding surface of the grinding wheel.

Fig. 8 is a section taken substantially on the line 8-8 of Fig. 2 looking in the direction of the EI'I'OWS.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other vembodiments and of being practiced or carried out in various ways.

.Also it is to be understood that the phraseology or terminology employed herein is for the purpose of. description and not of limitationn A machine of the present invention may be constructed and operated as a single independ- 'ent unit. or it may be mounted and used as a sub- 'assembly on agrinding machine. In either instanceit is mounted' on a fixed base ill which supports an arcuate flxed base plate H having atconcentric arcuate guide way I! extending vthrough the face and a peripheral way liforined in the circumferential edge thereof. ,.'I 'he periph-I eral way l3 is adapted to guide a clamp lip ll and provide an edge for the adjustable clamping of the grinding flxture by the ad ustable v clamp |5 into a variety of'adjusted positions.

Fig. y1 is a fragmentary perspective of a ma- 'Y chine for dressing the working surfaces' of an abrasive grinding Iwheel, the machine embodying the present invention being shown in its op- The entire wheel dressing unit is mounted on a plate I 6 which is pivotally mounted at thepivot point- I'Il *on' the base plate II. The plate IS carries a guide member l8 mounted for movement in'the way [2 and also carries the' clampingmember IS at a point adjacent the circumferential portion of thebase H; Thus the plate dressing machinerelative to the fixed plate ll when the clamping member 15 is loosened. The plate |3 may be held in any desired adjusted position relative to the plate ll by the clamping action of the clamp |5 in the peripheral way l3 of the flxed plate Il.

VAn adjustable slide member 23 is carried in ways 2| and 22 which kare mountedon the p;votal |3 may be adjustably swung about the pivot 11 be placed on the opposite end thereof. when the pivoted plate is moved to the dotted line posiplate IG. -..The adjustable slide member is held in a predetermined position in the ways 2l and 22 by adjustment of the slide adlusting screw member 23.

Mounted on the slide 23 is a flxed plate and guide member 24 on which is mounted the base portions of ball slides 25 and 23. The movable -Dortions 21 and 23 of said ball slides are carried by slide plate members 23 and 33 forming the sides of the movable power head member which is carried on har slide members 3| and 32 re-v spectively. The movable power head member comprises a base portion 33 having a motor'supporting bracket 34 carrying an adjustable motor clamping member 33 to which is secured a high speed electric motor 33 mounted for driving the drive pulley 31. An idler guide pulley 33 is mounted on the base portion 33 and guides the power transmission belt 33 which drives the power pulley 43 of a high speed grinding spindle .4I at the opposite end of which is mounted the dressing wheel 42.

The high speed grinding spindle 4l is mounted on a reciprocating slide bracket 43 which is carried on ball slides 44 and 43 which are mounted on the base 33.

The reciprocating slide bracket 43 is vertically reciprocated in the ball slides 44 and'43 vided with a looking slot 33 for holding a locking pin -31 attached tothe index pin 34.

Thus the base 33 and all the attached parts may be selectively looked against sliding movementl by movement of the index pin 34 in the bracket 33 so as to bring the pin into position for locking in any one of the plurality of index guide holes 33. To per-mitv sliding movementV of the base 33. the index pin 34 is with-I drawn from the index guide holes 33 and is held out of contact therewith by the action of the looking slot 53 on-the looking pin 31 carried by said index pin 34.1:

Sliding movement of the base 33 relative to the fixed plate 24. is effected and controlled by a manually actuated knob 33, which as shown in Flg. 4, is keyed to the end of the rotatable shaft 33 which is journalled in the side plates 23I and by the electric motor 43 which drives, through 33, and the sleeve bearings 33 and 3l iournalled in the'bar slide members 3l and 32 carried by the base portion 33.

A pinion gear 32 is keyed on the shaft 33 for rotation therewith and meshes with a stationary rack gear 33 secured to the fixed plate 24.

The knob 53 may be removed from the end of the sha-ft 33 as here shown, and if desired may tion shown in Fig. 6.

The dressing wheel truing fixture is carried on a, base portion 13 which is removably supported on the stationary'base ll. The flxture, as shown in Figs. 2 and 8, comprises a dressing tool holder 1| carried by the said base portion A diamond pointed dressing tool 12 is secured in the dressing tool holder 1l by a plurality of set screws 13 and 14 and is moved into adjusted wheel dressing position relative to the dressing wheel 42 by movement of the tool adjusting set screw 13. As shown in. Fig. 8, the base 13 of the dressing wheel truing fixture is provided with a depending stud 13 which is received in a hollow bushing 11 mounted in the flxed *base ll. f This construction 'permits the bodily removal of the 'wheel truing iixture during the wheel dressing operations as hereinafter more fully described and provides a flxed positive positioning of said fixture when truing the dressing wheel 42.

To assure accurate positioning of the pivotal plate'l3 when moved toythe position shown in Fig. l,-a stop 13 is provided in the slot ll in a position to contact the guide l3. When moved to theopposite position the 'guide [3 contacts the end of the slot i2. Thus the pivotal plate 13 is definitely held in predetermined position at each end of the arc through which it is moved during the grinding wheel dressing or truing operations.

The operation of a machineembodying the inclined faces 3! and 32 joined' in the arcuate 'circumferential face 33. Such a grinding wheel is used in grinding tungsten carbide thread gauges and is formed, dressed, or trued by causing the dressing wheel 42 to dress or Vtrue the flat inclined faces 3| and 32 and the arcuate face 33. It is to be understood, however, that by suitable adiustments other types 'or shapes of grinding surfaces may be formed, dressed or trued on any desired typev of grinding wheel. The present invention is, therefore, not limited to the forming, dressing, or truing of this particular wheel. j

When the machine of the present invention is positioned as shown in Figs. 1 and 2,.and in the solid line portion of Flg. 6, the dressing wheel 42 dresses or trues the inclined face 32. When moved to the dotted line position of Flg. 6 it is in position to dress or true the inclined face portion ll. In moving from the solid line position of Flg. 6 to the dotted line position thereof or vice versa, the index pin 34 is looked in a suitable index guide hole-33 so that as the plate I 3 is swung about the pivot I'I, the pivot l'l will act as the center which is required to generate a true arcuate face 33 on the grinding wheel 13. v.

* With all sliding portions of the machine thus locked. Lthe swinging of the. plate" carries the dressing wheel over the arcuate face 33 of the grinding wheel in a fixed predetermined arcuate path as may be required to generate the arcuate face 33. It is preferable that the dressing operations on the inclined faces Cl and 82 be comasraeaa the face to beidressed or trued and the index pin 54 is retracted from the index hole 53. The manually actuated knob 58 is then rotated manually to move the dressing wheel 42 back and forth across the face of the grinding wheel which is to be dressed or trued. During all the times that the dressing wheel 42 is in dressing or truing position relative to the wheel 19, it is rotated by the power drive to the high speed spindle'll which in a preferred embodiment, will be in the order 'of'fl approximately ten thousand revolutions per min- Iclaim:

l. A machine for dressing or truing the working surface of a grinding wheel and comprising a fixed base, a pivoted plate movable thereon about a 'flxedcenten a power driven rotatable dressing wheel carried on said pivotal plate and mounted I for horizontal and vertical reciprocation relative .to the said working surface of the said grinding wheel.. 1 v

2. .A machine for dressing or truing the working surface of 'a grinding wheel and comprising a fixed base, a pivoted' plate movable'thereon ute. At the Isame time the dressing wheel 42 is' moved and reciprocated vertically by the motor driven connecting rod 49. Thus the dressing wheel 42 is .moved bodily both vertically and horizontally relative tol the surface to be dressed or trued-at the same .time that it is rotated while in contact with the surface which is to -be dressed or trued. During the dressing or truing operation, the grinding wheel 19 is rotated at approximately its normal grinding speed. Variations in the generated surfaces due to irregularities in either the grinding wheel surface or in the dressing wheel surface are thus largely eliminated as the movements of the wheels during the dressing or truing operations cause any such irregularities to be effective only over the entire operation.

After performing several dressing or truing operations on the grinding wheel 18, it is advisable to 'true the dressing wheel 42. In this operation, as shown in Fig. 8, the diamond wheel truing tool fixture'is -placed on the base ll and the diamond truing point of the tool 12-is brought into adjusted position on the periphery of the dressing wheel 42.' The wheel 42 is rotated and reciprocated horizontally and vertically relative to the tool 12 until the dressing surface thereof is restored or trued as may be desired. Due to the Iremoval of a portion of the wheel 42 on each truing operation, the adjusting member 23 is suitably adjusted to move the slide and thus about a fixedy center, a power driven-rotatable dressing wheel carried on said pivotal plate and mounted for horizontal and vertical reciprocation relative to the said working surface of the said grinding wheel, and adjustablev meansfor moving said dressing wheel bodily toward and away from said working surface of said grinding wheel to permit the use of different sizes of dressing wheels on said machine.

ing surface of a grinding wheel and comprisingy a fixed base, a pivoted plate movable thereon pensate for such differently sized dressing wheels,

and assures that the dressing wheel surface will be brought into suitable wheel dressing contact -with the grinding wheel with which the device is the uses herein described, it is not expressly limited thereto as it may be readily adapted for numerous uses of a similar or related nature by slight modiflcations and adjustments which may be readily-effected by any mechanic skilled in the art. It will be seen, therefore, that a machine as herein described provides a suitable device for .accurately dressing or truing the working surfaces of a grinding wheel within close prei cision limits.

Having thus described m'yinvention, what I precision limits;

about a flxed center, a power. drivenrotatable vdressing wheel carried on said pivotal plate, and

wheel carried on said pivotal plate and meansv including a manually actuated slide member for moving said dressing wheel horizontally and a power' actuated reciprocating slide member for moving said dressing wheel vertically relative to the said working surfaceof .the said grinding wheel, and adjustable means v for moving said dressing wheel bodily toward and away from said working surface of said grinding wheel to permit the use of different sizesof dressing wheels on said machine.

5.'In the method of dressing the working surface of a grinding wheel, the novel step of rotating a dressing wheel across the working surface of said grinding wheel while bodily moving said dressing 'wheel horizontally and vertically relative to said grinding wheel. i i

6. In the method of dressing the working surface of a grinding wheel, the novel step of rotat- -ing wheel' horizontally and vertically relative to said grinding wheel, 'while maintaining an adjusted set position of said dressing wheel relative to the working surface of said/grindinglwheel thereby to dress a working surface on said grinding wheel to a predetermined contour within close '7. In the method of dressing' the working surface of a grinding wheel, the novel step of rotating a dressing wheel across theworking surface of said grinding wheel while moving said dressing wheel horizontally .and vertically relative to-said surface, and swingin'g said dressing wheel into a plurality ofadjusted positions for dressing the opposite sides and edge portion of the working desire to Isecure by United States Letters Patent surface of said-grinding wheel within closeprecision limits.

8. In a method of dressing the working surface i of an abrasive grinding wheel, the novel step of rotating a dressing wheel across the said working surface while moving said dressing wheel horizontally and vertically relative thereto and main-' taining an adjusted set position of said dressing wheel relative to said working surface to dress said working surface to a predetermined. contour within close precision limits, and swinging said dressing wheel into a plurality of adjusted positions for dressing the various portions of said working surface.

9. A machine for dressing the working surface of a grinding wheel and comprising a fixed base, a pivoted plate movable thereon about a fixed center, a power driven rotatable dressing wheel carried on said pivotal plate and mounted for horizontal and vertical reciprocation relative tothe said working surface of the said grinding wheel, and a manually adjustable clamp for securing said pivoted plate to said flxed plate in a plurality of selected adjusted positions.

* 10. A machine for dressing the working surface of a grinding wheel and comprising a flxed base,

a pivoted plate movable' thereon about a flxed center, a power driven rotatable dressing wheel carried on said pivotal plate and mounted for horizontal and vertical reclprocation relative to the said working surface of the said grinding wheel, adiustablemeans for moving said dressing wheel bodily toward and away from said working 'surface of said grinding wheel to permit the use vof different sizesof dressing wheels on said ma-L chine, and a manually adjustable clamp for securing said pivoted plate to said fixed plate in a plurality of selected adiusted positions.

- 11.' A machine for dressing the working surface of a grinding wheel and comprising a fixed base,

a pivoted plate movable thereon about a fixedcenter, a power driven rotatable dressing wheel carried on said pivotal plate and mounted for horizontal and vertical reciprocation relative to the said working surface of the said grinding wheel, and including a manually actuated slidemember for moving said dressing wheel horizontally and a power actuated reciprocating slide member for moving said dressing wheel vertically relative to said working surface, and a manually adjustable clamp for securing said pivoted plate to-said flxed plate in a plurality of selected ad- Justed positions. v

' GEORGE F. EGLINTON.

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