US1688468A - A voluntary associa - Google Patents

Description

Oct. 23, 1928.

A. E. MAYNARD GRINDSTONE Filed Dec. 4, 1926 '2 Sheets-Sheet l Patented Get. 23, 1928.

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ALBERT E. Ivl'AYNlBD, G SOUTZ-IBRIDGE, MASSACHUSETTS, ASSIGNOB TO AMERICAN OPTICAL COMPANY, OF SGUTIIBRIDGE, MASSACHUSETTS, A VOLUNTARY ASSOCIA- TION OF MASSACHUSETT'.

GRINDSTONE.

Application filed. December 4:, 1926. Serial no 152 554.

This invention relates to improvements in grindstones and has particular reference to a split or divided 'rindstone for grinding bevel edges.

5 The principal object of this invention is to provide improved means for separating a divided or split rindstone so that it. may be trued.

Another object of the invention is to provide simple and e'fiicient means for holding together in aligned position the portions of a divided or split grindstone.

Another object of the invention is to provide simple and means for truing a bevel grooved grindstone in which the bevelled parts of the stone may be separated.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings and it will be understood that many changes in the details of construction and arrangement of parts may be made without departing from the spirit of the invention as expressed in the accornpanying claims. I, therefore, do not wish to be limited to the exact details of construction and arrangements shown.

' Referrin to the accompanying drawings: Figure 1 is a front elevation of a mounted grindstone embodying the invention;

Figure 2 is a fragmentary cross sectional view on line 22 of Figure 1;

Figure 3 is a top or plan view of Figure 1 shown partially in section.

Prior to my invention bevel grooved grindstones have been made in one piece with a bevel groove in the periphery. It has been found from experience that it is difficult to true such stone due to thefact that the truing is not correct in the bottom of the groove. It has also been found that such a stone is not exactly accurate in its grinding propertiesdue to the fact that the bottom of the groove cannot be perfectly madein such a stone.

It is the object of my invention, therefore. to overcome these difficulties of grinding and of truing by simple and eilicient arrangements of separating the stone on the division lineat the bottom, of the groove.

Referring to the drawings wherein similar characters denote corresponding parts throughout, a grindstone 1 made in two halves 2 and 3 and having the bevelled faces 4 and 5 is mounted on a shaft 6 in the bearings 7 and 8. The grindstone is turned by the pulley 9 and'the belt 10 in the usual manner. The sections2 and 3 of the grindstone 1 are mounted on a hub or carrier 11. The section 3 is directly secured to the hub 11 by means of an adhesive strip 12 while the section'2 is slidably connected to the hub 12 by means of the adjusting collar 13 to which it is secured by an adhesive strip 14. The adjustable collar 13 is screw threaded at- 15 to the hub 11 and has in its periphery, openings 16 for a spanner or other wrench connection. The section 2 may be advanced by turning the collar 13 until it engages the section 3 making in effect a complete bevel edge grindstone having the bevels 4 and 5. By reversing the action of the screw collar 13 the parts 2 and 3 may be separated. The hub 11 is secured to the shaft 6 by means of the key 17 so that the grindstone members 2 and 3 rotate with the shaft 6.

hen the parts of the stone 2 and 3 are separated as shown in Fig. 3 the section 2 is locked against rotation on the collar 11 by means of the set screw 18 which is tightened up after the section 2 has been brought to the position shown in Fig. 8. This is done so that the truing of the stone may be carried on as described hereinafter without having the section 3 rotate on the screw thread of the hub 11.

The bevel edges 4 and 5 of the stone sections 2 and 3respectively are trued by a diamond point 19 held in place on the truing rod 20 which slides in the guide members 21. The guide members 21 are secured to a base plate or frame 22 which in turn slides in the slide way 23 on the base 24 of the grindstone frame. The plate 22 is advanced towards or withdrawn from the grindstone by means of the screw 25 having the turn nut 26. The truing rod 20 has a handle 27 by which the truing rod may he slid longitudinally in the guide 21 to advance it towards the ston or withdraw it therefrom, the guides 21 being related to the grindstone on the angle of the bevel faces of the stone one on each side. The truing rod 20 is retained in place in the guides 21 by means of the collar 28 which is located in ting angle to the bevel face or place by the set screw 29 and which may turned by the handle 30. The truingi ro is prevented from turnin in the gut by means of the pin 31, thepin ope the groove in "nines 19 mounted o1 oteo of the set screw pivot 34 by wh mend point 19 may be so,

In the trump; operation the tr vanced by means of the scren posit-ion with relation to the o and the truing rod 20 nnshc l in the guides 21 dmina; the this pushi back and i hand. lVh l 3 of the grincst completed the mend :oint 19 is on the opposre s' re tl rough as above o y to =3 In this way each s te or trued to the pronerbeve.

- shown in J understood that before is performed the two po i'tions of tl 2 and 3 are separated by the colla scribed and atter the trui been done the two s brought up to hear one a5 shown in Fig. 1. The from turning); by means 0" which tightens the collar The dian end or cutting pi, "T 1 position by the screw pivot driver, the screw having; the re head slot.

From the foregoing description it will b seen that I have proviced a simple, ctli' and economical means for producing a divided bevel grindstone wherein the pa tsm 1; be readily separated or locked to, ;ether a wherein the par s may be accura 'e y and ciliciently trued, thus insu proper reenest-i: of the groove at its bottom so that the work that is being; bevel ed in the-g ro e will have a true apex.

Having describec the in; Cl'ltl" 1. A bevelled edge prising; a base, Sllil'i' r i the base, a grindstcne hub on the shaft, a sectional 'rin ,xer the .iub having an angzged glancing ccgre, a second sectional 'indstoae n ember movebly mounted on the hub and ham in an angled grinding edge, the diameters of the adlaecnt faces of the grindstone members than those of the outer feces, no locking; the-second grindstone nembe' the hub in spaced relation to the first stone mem-- base hevine n U ber, guide way members on i ective angled g'rmchn edges of the grilles n, I claim:

,unted on truing tool ,e uides parallel to the l one members whereby each angled face of grinding ft edges oi. the grindstones may be -rued by a truing tool in. the truing tool guide when the sections of the grindstones are separated and both secti ns locked with respect to the A bevelled ed;

a base, a s 'HlilliGL'l on l a 1 1,,, i nub on the sectional grindstene memberon the hub aving an angled grinding edge, a second sectional grindstone member movably d on the he; and having an angled edge, the diameters of the adj cent storm members being" short l c ides on the base towards and away the the grgrzndstmic sections. 9 r ,1 L; l v" 1* oer will. ed; grinding; macisnc coinine' a l; iat't rotal'c y mounted on ll, base, a gri'intlstone holdL g hub on the lime, a sect onal grindstone member m the nub and having an :mgled grinding edge, a second sectional grinc s onemember movably :r'iounted on the hub and having an iglec. edge, the diameters of the adjacent faces ol the grindstone members being shortei than those of the outer faces, means for locking the second grindstone membe on the hub in spaced relation to the first grindstene i ember, guide way members on the base hav 9 truing tool gruidcs parallel o the respec- .e angled grinding edges efthe grindstone incn'ibers, and a separable'truing tool in one of the truing tool guide-ways.

i. A bevelled edp grinding; machine comprising; a base, a shaft r: tatably moon-tee on the basc, a 'rindstone holding hub ontlie shaft, a sectional grindstone member on the hub having an angled grinding edge, a second sectional grindstone mem er movably n ounted on the hub and having an angled. L incline edge, the diameters of the adjacent faces 1" the grindstone members b ing short or than those oi? their enter it es, means for ie of the outer ifaecs, 1neans for lockingthe second grindsione member on the hub in spaced relation to the first grindstone ALBERT MAYNARD.

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