US2051618A - Block for sectional grinding wheels - Google Patents

Description

Aug. 18, 1936. F. c. PENNY I BLO C K FOR SECTIONAL GRINDING- WHEELS Filed Oct. 16, 1934 lyvENTOR ATTO R N EYS Patented Aug. 18, 1936 UNITED STATES PATENT. OFFICE The Bridgeport Safety Emery Wheel Com pany, Inc., Stratford, Conn, a corporation of- Connecticut Application October 16, 1934, serial'Norvisass 6 Claims. (01.51-20'9) v flanges is divided into a plurality of pockets by This invention relates to new and useful improvement in blocks for sectionalgrinding wheels of the type shown in patents to Hyde, Numbers 1,133,475- and 1,589,855 of March 30, 19-1 5, and June 22 1926, respectively.

An object of the invention is to provide animproved construction of shoe for the blocks ofa sectional grinding wheel. More specific objects of the invention are to provide a shoe for a block of a sectional grinding wheel and which shoe is light in weight and comprises aminimum of metal and may be manufactured at low cost whereby it need notbe returned to the factory for refilling when the abrasive blockis worn down.

Additional objects are to provide a-shoe a'sindicated and which is so'constructed asto be firmly attached to the block to which it is moulded, and which does not materially" detract from the cross section ofthe block in its shearing zone, and whichprovides means whereby a marker plug may be moulded directly into the abrasive block on its inner end. I i .i Other objects and advantages will'become apparent from a consideration of the'following de-' tailed description taken in connection with the accompanying drawing wherein a satisfactory embodiment of the'inven'tion is shown. However, it will be understood that the invention is not limited to the details disclosed but includes all such variations and modifications as fall within the spirit of the invention and the scope of the appended claims;

In the drawing: v Fig; 1 is a front elevational view showing a portion of a sectional grinding wheel;

Fig.- 2' is a sectional view taken substantially along the'plane of the line 22 of Fig. 1; Fig. 3 is a front elevation'al view, on-an enlarged scale, showing an abrasive block andshoe; with part of the abrasiveblock broken away;

. Fig. 4' is'a sectional view taken' substantially along the plane of the line 44' ofFig. 3;

' Fig; 5 is a rear elevational view of the shoe alone, on the scale of Fig.3; and

.Fig. 6 is a detail-sectional view taken substantially along the plane of the linefi -liof Fig.3. Referring in detailt'othe drawing a portion of a sectional grinding wheel is shown at It] and theisame compri'ses'a; supportincluding a carry ing disc ll having ahub l2 for attachment toasha'ft', a portion ofwhich isshown at l3, and said inner peripheral edge 2T the body and flange 2B transversely extending divisional webs or memhers I! which are secured-in place in any suitable manner; 'I-he wheel I is assembled with two grinding blocks [-6 ineachepockeh-and suchblocks are r ferably shaped in cross section substan-' tially as bestshown' in Fig;- 1 although not necessarily' so.- Blocks l-6 are secured "or clamped in position by means of tapered wedges l8' in the spaces betweentwo adjacent locksand the wedges 10 are adjusted by screws- 18 passed through the inner flange M'of'the support andsuchscrews are locked-in adjusted position as by nuts 20: 7 These wedges clamp the blocks against the flange I5 and Webs I 1. I

7 Each grinding blockl6 includes an abrasive block or portion 21 and a metal shoe 22"secur'ed to theiiiner end of the abrasive portion as by being moulded thereto.- Shoe'22 is in the form of an openffame-likestructure incl'udingabo y portion- 23 having inner and outer peripheral edges. An outer flange 24 extends forwardly from the outer edge of the body 23 and such flange is tapered o'nitsf innefsid'e" 2 5 whereby it is thinnest at'its-for'war'd or"fre'eedge. Afiang'e26 extends forwardly from the inner'peripheral edge of the body 23 and this-flange in addition to extendirfg fo'rw'ar'dl'y ir'iclines' inwardly of the shoe or in adirection aweynom the outer flange'24 Gn its have ae mmuous' tap'er from the forward or free edge ofthe flange 26 throughtofthe r'ear'surface' of the body.

' As 'here' shownfa rib 28'" extends transversely across the bodyand such rib -may be centrally '5 enlarged and in such enlargedjportion provided with atapped opening 295 The inner flange 26 (innate- 1y extends along" the opposite sides of rib 28'; andwhere such flange is on the rib it is deslgn'ated fifariditisfhfther noted that the continuo-u's ta'p'er 2-1 is-carried outon the portion 30 of the flange whereori the tapered surface'is designatd flli From thisit- Will beunderstood that-looking into the-froiit*of-the-shoe 22 as in Fig Q3 tIie oppo'sed surfaces 'of the'flanges 24 and 26 inenne a'wayrrom one-jano'therandthat the flange-portions 30 of the'rib-28 incline away from theme;- W

Whenthe' abrasive-material 21 is moulded to the Slide '22 to fo rm a'c0mp1 e t e blOCk the said mater al'entersinto the-spaces between the flanges zt' and z'e 'and-also enters the openings 32-and 33 through the rraine-nkeibody or theslio'e. It will be understood that the rib- 2a divides the space through the shoe into twoparts whereby thetwo openings 32 and 33 are formed. The abrasive material entering the openings 32 and 33 in the body of the shoe passes to the rear of the flange 26 and completely fills the openings, entering under the inclined surfaces 21 which as above stated extend from the forward or free edges of the flanges 26 to the rear surface .of the body of the shoe. From Fig. 4 it will be clear that the material thus interlocks with the shoe in such a manner that when the material is set and hardened the shoe and the abrasive material are bound or moulded together with the shoe dovetailed to the abrasive material by means of the flange 2B and the inclined rear surface portions 21.

When the block it is being moulded a marker, plug 34 may be moulded into the rear end of the abrasive material. This is accomplished simply by disposing the plug in one or the other of the openings 32 and 33 with the plug facing toward the rear of the shoe 22. That is as the block is ,molded with the shoe in a horizontal position with surface 23 resting on the bottom of the flask the disc 34 is merely placed face down on this bottom within one of the openings 32 or 33 and then the plastic abrasive material molded onto the shoe and the disc. In this way a. plug carrying marks indicating the grade and grain size of the abrasive material is moulded into the completed abrasive block so that the block is permanently identified, the marker plug being so located as not to be worn away as the block is used but is easily visible. 7 The threaded opening 29 of each shoe receives an adjusting screw 35 and the abrasive portion 2| of theblock is provided with an opening 36 accommodating the screw. The screw of each block passes through an opening 31 in the disc ll and has a flange 38 engaging the inner wall of the disc whereby movement of the screw in one direction is limited. On the opposite side of the disc is a lock-plate 39 which is forked at one end so as to be passed into an annular groove 40 in the screw 35 wherebyto prevent withdrawal of the screw. Plate 39 is secured to the support as by a screw 4| which must, of course, beloosened before the plate may be shifted. If no'adjusting screw is used the tapped opening 29 may be omitted.

The manner of adjusting the blocks 16 is described in my patents above referred to and forms no particular part ofthe present invention. The

present invention relates to the shoe 22 and the abrasive block molded to it and it will be noted that since the shoe is in the form of an open frame it includes but a minimum of metal and is light in weight. As the inner flange 26, which may be continuous or may be interrupted as by the rib 28, enters into the abrasive material 2| at an angle or so as to form a dove-tail connection, with portions of the abrasive material at both the front and rear sides of the flange, it will be appreciated that the material 2| and shoe 22 are securely locked together.

Shoe 22 may be a casting or a pressed or forged shoe, and when cast may be moulded without the use of cores. This is true since the pattern may be easily withdrawn from the sand in which either of its faces is moulded, that is, on the rear face of the shoe there is but the one continuous incline 21 and on the forward face of the shoe 1 the opposed surfaces of the flanges 24 and 26 taper or incline away from one another toward their free edges. It can therefore be molded with straight draws on the pattern. Since the shoes include but little metal and since they may be cheaply moulded without the use of cores they represent very little loss when thrown away after the abrasive block is worn down. These shoes may be manufactured at such prices that it is not necessary that they be returned to a factory for refilling after the original abrasive block to which they were moulded has been worn away. The shearing zone or section in the blocks l6 would be at the forward edge of the outer flange 24 of the shoe. That is, the shearing section is the cross section of the abrasive block at the edges of flanges 24 so it will be seen it is practically the full cross section of the block. In the present shoe or with the present shoe this shoe and the abrasive block are firmly secured together without having any inwardly extending projection on the free edge portion of the outer flange 24 of the shoe. In fact, this flange is thinnest at its free or forward edge so that the cross section of the abrasive portion 2! is not materially reduced in its shearing zone or section, which zone, as above explained, is at the free edge of the flange 24. Therefore, with the present construction the abrasive portion of the block may be worn down further or a greater part of said portion of the block may be used, with little dang ger of the block shearing off or breaking. This fact coupled with the fact that the shoes 22 contain but a minimum of metal and may be easily moulded without the use of cores makes it reasonable to discard the shoe of a block when the abrasive is worn down, and not return the block to the fatcory for refilling. Further, as above explained, with the present shoe a marker plug such as 54 may be moulded into the-inner end of the abrasive block or in that portion of the abrasive block extending through the rear face of the shoe, so that it will be readily visible to an operator or other workman positioning the blocks on a support, and it is not necessary to markthe shoe or cut or mold these marks in the abrasive itself. Having thus set forth the nature of my invention, what I claim is:

1. In a block fora sectional grinding wheel,

a metal shoe, a block of abrasive material moulds ed ontosaid shoe, said shoe comprising a framelike structure open at both the front and back sides thereof comprising a body having inner peripheral edges about the opening in the back and outer peripheral edges about the outside of the frame, inner and outer forwardly projecting flanges on said body at said edges, said inner flange inclining inwardly of the body away from the outer flange and having its rear wall inclined outwardly toward the rear surface of the body.

2. In a shoe for a block of a sectional grinding wheel, a frame-like structure open ,at the front and rear comprising a body having inner peripheral edges about the opening through the back and outer peripheral edges about the outside of the frame, a rib extending across the body and connecting a pair of portions thereof, .said rib having a tapped opening therein, a forwardly projecting flange at the outer edge of said body, a flange at the inner edge of the body and at each side of said rib and incliningforwardly of ripheral edges about; the opening through the back and outer peripheral edges about the outside of the frame, a forwardly extending flange at the inner edge of said body, said flange inclining in a direction away from the outer edge of the body, and the rear wall of said flange being inclined outwardly from its free edge.

4. In a shoe for a block of a sectional grinding wheel, a frame-like structure comprising a body open at the front and rear having inner and outer peripheral edges, inner and outer forwardly projecting flanges on said body at said edges, said inner flange inclining away from the outer flange, the inner surface of said outer flange being inclined outwardly whereby the flange is thinnest at its forward edge, and the rear wall of said inner flange being inclined rearwardly in the opposite direction.

5. In a shoe for a block of a sectional grinding wheel, a frame-like structure comprising a body open at the front and rear having inner and outer peripheral edges, inner and outer forwardly projecting flanges on said body at said edges, said inner flange inclining away from the outer flange, the inner surface of said outer flange inclined outwardly whereby it is thinnest at its forward edge, said inner flange extending about the inner edge of said body and having a rear. wall inclined outwardly and rearwardly from its inner edge.

6. In a shoe for a block of a sectional grinding wheel, a frame-like structure comprising a body open at the front and rear having. inner and outer peripheral edges, a rib extending across the body and connecting a pair of portions thereof, said rib having a tapped opening therethrough, a forwardly projecting flange at the outer edge of said body, a flange at the inner edge of the body extending forwardly and inclining away from the outer flange, with its rear wall inclined outwardly and extending to the rear surface of the body.

FRANK C. PENNY.

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