US2541844A - Abrasive wheel - Google Patents

Description

Feb. 13, 1951 A. s. TITCOMB 2,541,844

ABRASIVE WHEEL Filed July 12, 1949 3 Sheets-Sheet 1 O I J3 if? unnmuh w Hum w n mnmlmi? mm 12 IN VEN TOR.

ATTORNEYS Feb. 13, 1951 I A. s. TITCOIMB 2,541,844

ABRASIVE WHEEL Filed July 12, 1949 5 Sheets-Sheet 2 IN VEN TOR.

05 466;? Jiepa/a/ Efcomb fill/0am ATTORNEYS.

A. S. TITCOMB ABRASIVE WHEEL Feb. 13, 1951 3 Sheets-Sheet 3 Filed July 12, 1949 ATTORNEYS.

Patented Feb. 13, 1951 AI ENT OFFICE AB'RASIIVE Albert S l1"epard;Titcomb, SouthWarrem-R. 1.,

Application. Julyi'12; 1949, Serial No. 104,254

10 C ms, 1.

This invention relates-to; an abrasive: grinding wheelzwhich is composed-of a p r -o spaced; abrasive surfaces.

Abrasive-grinding;wheelsgof this character have. heretofore been constructed ofa grindingr ment composed of abrasive material shaped like a hollow cylinder, knowntin' thetradeas an inverted cup. The sidesof thecup areoften made of segments each locking into-x the next segment or sometimes by segments with spaces in between with locking devices, to hold-the sides-of the cup to theupper base of the .grinding wheel by means of whatis known in the trade as the chuck. This. wheel-is intended-for operating. on a mountingat thebottom of a rotating verticals-pindle on work fastened to amovable base-(eitherrotary orre.- ciprocative). and where. the revolving segments arepressed downward. againstthe. work.v It;is' also intended for apparatusonamoun-tingat one end of a. horizontal spindle on.iworklfastenedv to, a reciprocating table so that the revolvingse'g. ments are. pressed against the work. When the wheel. is applied tothe work, chips of the work and. also. of the cutting wheel arefformed. by, re-. moval of the stock .of each. This removed stock will load up or interfere with the efiicientcutting action of the usual types. of wheels, the cutting efiiciency of a wheel depending to a substantial extent upon the. elimination or removal of'this debris. Thus the particular shape of the block and arrangement. of the several blocks in'the.

wheel are therefore very. important from the standpoint of an efli'cient cutting wheel. It has been found that if'this loose stock is readily removed from the. grinding before'it becomes im-' bedded into the cutting surface of the wheel or segment, it is unnecessary to; dress the wheel as frequently as otherwise and even more often eliminatesrsuch' dressing entirely. This is because the loose stock fills in the crevices that is; loads the wheel so that the cutting edges of the rough surface are neutralized and forms a smooth uncutting wheel which causes heating, burning, and warpage of the work being ground. This friction, instead of cutting action, often causes sufficient friction to throw the work offthe magnetic chuck, generally used, sometimes with serious results.

One of the objects of this invention is to provide a grinding wheel which will have abrasive blocks of a shape which will be more advantageous than any shapes with which I am familiar for the purpose of a moreeflicient and freer cutting action in any unit of time;

Another object of this invention is to provide'a grinding wheel which. although providing a faster outiand making more chips of: work whilev grinding, the abrasive material will not wear away as fast and; the debris. will not load up. and therefore} the wheel will. maintain its' efficiency for-a on r-time.

Another object ofrthis-invention isto provide-a shaping of abrasive fblocksso' that the chipswill V beiself removed efiiciently and: thus prevent-loading ofrtheiwheel Another obj ectof-thisinvention is to provide abrasivev blocks which-will cause their: leading edgetohave an efficient plow actionwupon -the chips which; are formedto spread the chips: outwardly, and inwardly of the wheel as the cutting surface of the-blockadvances.

Another. object of; this invention. is to provide argrinding wheel which will run:-cooland f-ree of while providing... passage outwardly forundesired removedmaterial,

Another. object .of thisiinvention is to provide a cutting wheel. having. the abrasive blocks so are ranged that the leading. edge of onewill overlap the trailingedgeof the "other sothatsome abrasive surface will be. continually in engagement with' the work, yet provide free way for debris to v be self removed.

Another object of the, invention is to. provide an adjustable built-in plate which may be actuated by a single screw to back up the abrasive blocks and which may be adjusted so that the'block will r108 moved further out axially of the wheel as their wearing surfaces are used up to assure more complete'usage of the block.

Another object ofthis invention is to provide a plurality of different sized-- wheels by utilizing in the plurality of wheels aunit abrasive block which will be ofauniform size-and shape, the arrangement being such, generally, that more blocks will be used in a larger wheel than in a smaller wheel, thus decreasing the number of shapes required to cover diiferent diameters of grinding wheels.

Another object of this invention is to provide a clamping means which may becommon in a 91 Another object of this invention is to provide a simple form of clamping means for holding each of the abrasive blocks in position.

Another object of this invention is to provide a rapid yet dependable clamping means which may be actuated by a single screw for holding each of the abrasive blocks in position.

Another object of this invention is to provide.

a coolant guide for directing the application of the coolant to a location just in front of or to a proper part of each of the abrasive blocks as it is rotated about the axial center.

Another object of this invention is to provide an abrasive block which is so shaped that it will be prevented from tipping out of line when clamped in position.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is a top plan View of the wheel with a portion broken away to show the abrasive blocks and their relation one to the other;

Figure 2 is a side view or edge view of the wheel;

Figure 3 is a top plan view of one of the abrasive block holding units detached from its mounting plate;

Figure 4 is an elevation of this unit alone showing its'position relative to its mounting plate;

Figure 5 is a section on line 55 of Figure 4;

Figure 6 is a view similar to Figure 5 but showing the parts shown in Figure 5 in a different relative position;

Figure 6a is a view similar to Figures 5 and 6 but showing the block in a position between the positions shown in Figures 5 and 6;

Figure '7 is a sectional View on substantially line l'! of Figure 4;

Figure 8 is a perspective view of the body portion of the block clamping unit;

Figure 9 is a perspective view of the second portion or jaw thereof which is movable relative to the body to hold the block in position;

Figure 10 is a perspective View of the inner side of the stop or segment adjustment plate for use in holding the abrasive block or segment so that the cutting surface thereof shall be at a further extended position beyond the clamping shoe in order to consume, or use it up to full advantage; and

Figure 11 is a perspective view similar to Figure 10, but looking at the other inner stepped or contact side thereof.

In proceeding with this invention, I have constructed an abrasive block or segment of an elongated shape which will have pointed ends. The leading pointed end will be so positioned in the wheel that the opposite flaring edges from the leading end will have a plow action upon the chips and debris removed by the preceding segment. These blocks are all of the same size and shape for standardization and for grinding wheels of different diameters, and I usually mount more upon a larger wheel than on a smaller wheel in order to provide the size of grinding wheel desired. The blocks may also be arranged in overlapping circular echelon relation so that a continuous cutting surface is provided on the work thus preventing the opportunity for the stock being ground to rise, and at the same time pro viding necessary chip clearance between. The overlapping relation will be so spaced that the chips removed from the work may be thrown aside from the wheel by centrifugal force as well as by physical displacement of the plow action referred to above. Coolant is usually delivered at a location just inwardly of the circular cutting annulus of the wheel and flows to the work surface within this annulus. The coolant usually is laden with chips or broken off abrasive particles and settles on any horizontal surface just within the cutting annulus. In order to discharge ordirect the flow of the coolant, I have in some cases provided a shelf onto which the coolant is discharged, which shelf will serve somewhat to collect settlings which are carried by the coolant, and I have so shaped this shelf that it will have channels or openings which will lead the coolant to a point just ahead of each of the leading ends of the abrasive blocks which are utilized; thus directing the coolant to the most efiective point and a location where it will assist in removing debris which is formed by the cutting edge of the abrasive block.

The wheel comprises an annular mounting plate it as shown in Figures 1, 2, 4, 5, and 6 provided with a strengthening or spacing rib it also of annular form and of a radius less than the similar dimensions of the plate which extends upwardly from the clamp bodies. A member known as a coolant guide continues as at I! so as to provide a thin portion 58 extending inwardly and from which there depends a skirt l9. This thinner portion 8 with skirt !9 comprises the coolant guide. These portions are shaded in Figure 1. Although they are of a complex shape, this will be referred to later to show how such complex shape serves to direct the coolant to the location desired.

On the under surface of the annular plate l5 there is rigidly secured a plurality of abrasive block holders such as shown in perspective in the two complemental views Figures 8 and 9. The assembled units for holding the abrasive block are shown in Figures 3 and 7.

Each of these units comprises a shell or body 26 which is generally of arcuate shape providing an inner surface 2| for supporting the abrasive block designated 22. The width of this body or shell which is to extend axially of the rotating axis of thewheel is sufficient to give a good bearing surface for the block. The strip of material 23 which forms this body has a smooth outer surface and the body as a whole is of a graduated thickness as may be seen by its edge 24 so that the required strength may be provided. The body is essentially solid with recesses therein for purposes as will be hereinafter pointed out. One end of the body is turned inwardly in the form of a hook 25 to provide a socket 26 into which one end of the abrasive block 22 may be placed. The other end of this unit has a jaw 2! (see Figure 9) mevably mounted upon it so that it may engage the other end of the abrasive block 22. This jaw 21 has a mounting portion 28 and a hook shaped portion 29 which engages the abrasive block to be held.

The body 23 of the unit has one end reduced as at 39 to provide a sliding surface or face for engaging thereduced strip or surface 3] of the portion 28 of the jaw, the part 32 being cut away while leaving another spaced surface 33 to engage this surface 30 alon the lower edge I301:

t offthejaw, a'; gieq e 3e is for'me'd' m the" be 3 9' and a'tongue"35 'entrsthisgroov'e so that the opposite edges of the tongue willfbe' guided by the side walls of the groove. 1 This maintains'thmovement of the jaw'in a; desired 'wliich'it' shouldhavej and inorder that aw may be drawn toward clamping position,

the j there is a 'threaddfbor'e 3 t prbviu uparallel with:

thetonguels'ee'l ig'. Ql't'o be'erigaged by'a screw 31 (see Fi'gi '7): passingthrouglropening 38in the may 23i (see Fig.1 8) and' actuatedby its sunken hexagenal' socket head 391 by means" of a I-Ie'x. wrenchI A ece'ss' 4'9 afiords access thereto.

Anabrasive block 22 which has a periphery such as shown in Figure '7 or Figure 3 will be of an original height'as' shown in Figure 5 so that its 1 upper end willen'gage the under surface 6'8 of the plate Hi; While'oneof its ends 6! will fit into the recess 25", as shown in Figures '7 and 8, while its other end 52 will be grasped by the jaw 2-7 urged through the screw 3 l so as to grip it firmly i the holdin g unit. Suitable pads such aspaper, or gasket, or other textile fibrous material 63' will be" provided on the blocks along the engaging surfaces of the" end portions and center outside of the block so that the pressure will be applied through this cushioning means. The block, as will be observed in Figure 5, projects out beyond the unit 26 so as to provide a quantity of solid abrasive material for grinding purposes; however, as the work is operated upon, the grinding surface will be worn from the surface 65, shown in Figure 5, upwardly toward the edge of the clamping unit, and it is desirable 'that the abrasive block which has become worn :from use and of lesser axial dimension, may be :moved outwardly of the unit 213 so as to present :for use additional abrasive material.

In order to support the abrasive block 22, at a position outwardly from that shown in Figure 5, I have provided a member 61 as shown in perspective in Figures 10 and 11, to act as a variable abutment shoulder to engage the inner end surface of the abrasive block. The body 23 is recessed as at 58 so as to accommodate this member 6! in a position as shown in Figure 5 wholly within the member 23 so as to in no way interfere with the mounting of the abrasive block 22 when it is to engage the under surface of the plate !5. This member 6'! comprises an arcuate portion 69 from which there extends upwardly a strut E8 to engage the under surface of the plate 15. The arcuate portion 69 conforms to the shape of the body 23 and may be completely housed Within the recess 68 while the strut 10 engages the under surface of the plate i 5, as shown in Figure 5. The inner edge of this arcuate portion 69 is cut away at its lower edge H so as to provide an overhanging shoulder 12 which when moved inwardly from the position shown in Figure 5 to the position shown in Figure 6, provides a point of engagement for the upper edge 33 of the abrasive block, as shown in dotted lines in Figure 6, while when the member as r6? assist is" guidingthe serene i's'hioved inwardlya further amount, the'end 15 of the member 'serves" as" anabutment forthe abrasive block now reduced" to" the size" 22 as shown'in'Fi'gure 6; A mounting'for this member is as follows: I

An" opening l5is provided from the outside to the'recess 68 which'is'ithreaded for'the receptionof a plug 16 which is fixed in'this opening and'is provided with a threaded .bo'r'eii for the'rec'eption of" a threaded stud 78' which is rotatably' mounted inthe shelffme'mber' 6?. This rotatablemounting is accomplished by means ofa'he'ad 79 on the-stud 18'located'loosely in a socket 88 and' held between the surface 8'! of the member GT and a threaded cap 82 secured in a bore 83- through which the stud 18 is passed. Thisstud may be manipulated by means ofa sunken hexagonal socket 84 in its end which is accessible from the outside of the holding unit and by this arrangement and a suitable T wrench toolto turn'this stud; the member 5? may be moved inwardly to present either its shoulder l2 or its end M: as an abutment surface for the inner orupper end or the abrasive block 22 so that itmay be moved; in two steps. outwardly from the holding unit to more fully use the abrasive ma-- tenarin the block, before it is discarded. The surfaces 35 and 85 of the variable abutmentmember are cut away to. leave only bearing portions 8? and as so as to provide dirt clearance which-nzight otherwise unduly retard the move' ment of this shoulder member. Other cutaways are as at'el (see Fig. 10:) and 92. These cutaway surfaces connect withopenings 93 and M- so that the centrifugal forcewhich might tend to force dirt about the member 61' will tend to: further force it through the openings 93 and 94 so that it may be discharged from the wheel.

In operation, th rib it of the plate i5 will be attached to some rotatingmeans shown in dotted lines in Figure 2 at 96 having known perforations through which coolant will discharge downwardly and outwardly so that it will engage the portions 18 shown in Figure-1. As rotary action occurs, any dirt or grit in the coolant tending to collect along the upper, inner surface of the coolant guide I1 and IS, the coolant by reason of the openings or peculiar formation of the shelf I 8 will provide spaces 9'! through which the liquid will descend so as to be in a position just ahead of the leading end of the abrasive block 22 so that it will better perform its action.

The abrasive block which I have illustrated may be of different shapes, but fundamentally will have an acutely angled leading end and pref erably for reversability will also have the same shaped trailing end, although this is not necessarily so.

I claim:

1. A clamping device to hold an individual bonded abrasiv block comprising a body member having an end formed into a hollow V to receive one acutely angled end of the block in a wedging action, a jaw, means to move the jaw with relation to the body member toward and from the body member to bind the block of abrasive into such wedging action, and a single tongue and groove joint between the upper and lower edges of said jaw and body member to guide the jaw in its movement.

2. A clamping device as in claim 1 wherein a single screw in alignment with said tongue serves to move said jaw.

3. A clamping device as in claim 2 wherein said single screw is rotatable in said body and has threaded engagement with a hole in said jaw.

4. A clamping device as in claim 1 wherein the single tongue is on said jaw and a single groove is in said body member.

5. A clamping device to hold an individual bonded abrasive block comprising a base disposed at right angles to its axis of rotation, a body at right angles thereto, a jaw to hold an abrasive block between the jaw and body and extending away from said base and a member having a step therein to provide an abutment intermediate its top and bottom edges and mounted in said body for movement radially inward at right angles to said axis of rotation to be engaged by said block to space the block from said base.

6. A clamping member as in claim 5 wherein said member provides an end abutment surface and may b selectively held in difierent positions to variously space said block from the base.

7. A clamping member as in claim 5 wherein said abutment member is provided with threaded means located Wholly radially outwardly of the abrasive block for movement of the member at right angles to said axis of rotation.

8. A grinding wheel comprising a plurality of individual bonded abrasive blocks arranged in circular echelon relation each with a wedge shaped leading inner edge extending generally parallel to the axis of rotation and a guard presenting a horizontal lip with vertical channels for the downward movement of the coolant at the locations adjacent each of said leading edges.

9. A grinding wheel as in claim 8 wherein said wheel is annular and said means comprises a horizontal guard to catch the coolant and direct it outwardly and circularly, said guard terminating at intervals for downward vertical movement of the coolant.

10. A grinding wheel comprising a plurality of individual bonded abrasive blocks held in a chuck arranged in circular echelon relation, each with a wedge-shaped leading inner edge extending generally parallel to the axis of rotation and 1 within the inner contours of said abrasive blocks,

a coolant guide presenting a horizontal lip extending over the top anda vertical skirt along the upper inner end and upper inner side of said abrasive blocks, said contour of the skirt of said coolant guide providing channels for the downward flow of the coolant to the inner leading edge of said block.

ALBERT SHEPARD 'I'ITCOMB.

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

UNITED STATES PATENTS Number Name Date 436,892 Harrington "Sept. 23, 1890 524,572 Beckert Aug. 14, 1894 1,416,475 Knowls May 16, 1922 1,600,054 MacLaughlin et a1. Sept. 14, 1926 1,641,799 Brandes et al. Sept. 6, 1927 1,767,321 Skillings June 24, 1930 1,794,992 Stratton Mar. 3, 1931 1,797,526 Hoagland Mar. 24, 1931. 1,892,434 Larsson Dec. 27, 1932 2,102,919 Rusofi Dec. 21, 1937 2,476,334 Titcomb July 19, 1949

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