US1860614A - Mechanism for truing and dressing grinding wheels of centerless grinders - Google Patents

Description

y 31, 1932- F. J. HOHNHORST ET AL 1,860,614

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS OF CENTERLESS GRINDERS Filed March 14, 1950 5 Sheets-Sheet l II III \llllllH y 3 1932- F. J. HOHNHORST E AL 1,860,614

MECHANISM FOR TRUING AND DRESSING GRINDING WHEELS OF CENTERLES S GRINDERS 5 Sheets-Sheet 2 Filed March 14, 1930 [N ENTORS y 1932- F. J. HOHNHORST ET AL 1,860,514

MECHA M FOR TRUING AND DRESSING GRINDING EELS OF CENTERLESS GRINDERS I Filed March 14,

1950 3 Sheets-Sheet 3 Patented May 31, 1932 UNITED; STA

res PATENT OFFICE FERDINAND .rizionmions'r, AND FERDINAND Jfk oEeEn, F covIiveroN, KENTUCKY machines,

. means MEC ANISM son TRUING annnnnssme GRINDING WHEELS or CENTERLESS' emmmns 1 v 1 Application filed March '14, .1930. Serial K014355823.

Our invention relates to mechanism for truing and dressing grinding wheelsi such as emery wheels, including carborundum wheels. and the like, in centerless grinding in which the work is rotated by peripheral contact with the peripheries of op posed grindingwheels rotating at difierent p ed The'grinding wheels employed in grinding metals and similar hard substances in ma- .chi'nes-of this character are composite grinding wheels containing comminuted or finely divided emery, carborundum or other cutting medium and a suitable bond, suitably .bound together as a composite mass, the fine: ness of the grains of the cutting medium determiningthe-coarsenessor fineness of the g nd g-.1 V y I It is the object of our invention to prov de novel-means for truing or ingsurface of the grinding wheel or 'wheels in a machine of this character; further,to provide a composite abrading wheel and .means whereby. to present the composite 'abrading wheel to the grinding surface of the grindingwheel under thehoodof the grinding wheel; further, to provide novel means for supporting the abrading wheel; further, to'provide novel means fortraversing the support of the abradin g wheel while projecting through the hood of the grinding wheel; further, to provide any abrading wheel .and means for mountingthesame at an angle to the periphery-of the grinding wheel under the hood of the grinding wheel; and, further, to-provide novel mounting for the abradingwheel extending through aslotin the hood of the grinding wheel for permitting lateraladjustment of the abrading wheel across the {face of the I grinding-wheel and a slide movablewith said mounting; for maintaining closedrelation of 7 said slot to prevent the passage of'grinding dustand particles therethrough.

The invention will be further readily unfderstood from the following description and claim, and from the drawings, in which latter I Fig. 1 is a slde elevation of an exemplifying dressing the grind the space between the grinding, wheels. structure and form ofthe support is depend- ;centerless grinding machine embodying our invention, partly broken away.

Fig. 2 is a plan vlew of the same, partly broken away.

device, taken on the line of Fig. 2. Fig. 4 is a cross-section showing an exemplifiedbearlng means for the abrading wheel of our improved device taken on the line 4- 1 ofFig. 3. Fig. 5 is a cross-section taken in the plane of the line 5-5 of *Fig. 8, with the closing plate removed.

Fig. Gis'a cross-section showing the clamping means for the sleeve taken on the line 66 of Fig. 2; and,

Fig. 7 is an axial sectiompartly broken :away, showing a modification of our improved device. r z I v The exemplified centerless grinding ma chine comprises a frame 11 which has a hearing 12 in which the shaft 13 of a grindingwheel 14 rotates. The shaft is suitably driven, and the grinding wheel is suitably releasably secured to the shaft. This grinding wheel is the mainv grinding wheel of the cou- 19 on the main frametowardand from the grinding wheel 14. The means for adjusting and moving the auxiliary grinding wheelare not shown because wellknown.

A' support 21 for the work entzonthe work to be ground. 7 r

, Ahood 25 is received aboutthe grindingv wheel 14, anda hood 25 is received -about the grinding wheel 15. These hoods-encomor dressing means are respectively mounted on the respective hoods and project through said'hoods. They may beyoffsimilarconstruction, although onema'y differ from the other in non-essential details. The abrading is located in .The

Fig. 3 isan axial section of our improved 5 pass the ma or'portions of the peripheries of ing ing a guideway 28 on which a slide 29 is arranged to moi e laterallywith relation tothe plane of the grinding wheel 14.

' A screw-shaft 31 is journaled in a bearing 32 on the guide and is held endwise therein, the screw-rod being threaded in a threaded nut 33 fixed on the slide. A hand-wheel 34: 'isfixed to the screw-rod for rotating the same and thereby moving the slide laterally.

The slide is provided with a bearing 35 in "which asleeve 36 is adjustable axially. The sleeveis arranged to be clamped in adjusted positions in the bearing by means of a clampshoe 30clampingly acted on by a clamp-bolt "37. This sleeve is preferably movable axially in said bearing toward and from the grinding-wheel in the hood for locating the abrading wheel 38 in approximate position with relation to the grinding wheel.

The sleeve is provided with a bore 39 in "which'there is a shank 40 of a mountin for the abradin wheel. This shank is a ]ustable axially 1n the sleeve, as by providing the Shank with an axially threaded portion 41, in which a feed-screw 42 is threaded. The "feed-screw has a journal-portion 43 in an axial bearing 44 'at the outer end of the sleeve, and isprovided with a hand-wheel 45 for r0- tating the feed-screw. The feed-screw is held endwise in its bearing by locating the be-aringbetween a collar 46 on the feed-screw and'the'hub of the adjusting wheel 45. The

- earing is secured to the end of the sleeve, as

with means by means of screws 47. The inner end of the shank is provided forsecuring the abradlng part thereto. These are exemplified as comprisinga fork 51 having axhood 52. The fork provide'dwithbearings 53. IAn axle 54'is in said bearings, as by nieansof clampbolts 55 securingthecaps 5 6 ofsaid bearings so the fork5l of said shank or mounting for fheabrading wheel. I A shell 61 has ball- bearings 62,63, 64, 65, therein, arranged in pairs, the outer raceways of the pairs being separated by. a ring 66. A plug '67 is threaded in the shell and clamps the. outer'raceways and ring between a ShouIderBB'inthe shell and said plug.

The axle is provided 'wth a flange 69 10- cated'between the'inner raceways of the respective pairs of ball-bearings. Annular said hole.

spaces 70 are located between the outer ends of said inner raceways and the end Wall 71 and said plug 67 respectively. Said wall and plug are provided with inner peripheries 72 making close joint connection with the outer periphery of said axle. I

The axe is provided with a passage 74 having a branch 75 connecting with the space 76 in said shell and with a branch 77 connecting with the passage78 in one of thebearings 53, the outer end of the latter passage bein provided with a lubricant fitting 79 througl i which lubricant may be introduced through the passages and into said hollow of the shell for lubricating the bearing.

The abrading wheel is a composite abrading wheel comprising grains of emery, carborundum or other cutting medium of suitable fineness, dependent onthe fineness of the work to be done, and a suitable bond, a

suitably bound together as a composite mass, preferably of a texture much'harder than the texture of the grinding wheel, and of substantially smaller diameter than the grinding wheel.

The abrading wheel is rotated by peripheral contact with the periphery of the grinding wheel. It is preferably held ina plane at an angle to the plane of the grinding wheel.

The grinding wheel during operation 'be- It comes impregnated with particles of dirt or metal from the work being operated on and become comparatively glossy and thereby loses itsgrinding effect, its granular structure also becoming dull at the grinding'face, thereby reducing its grinding or polishing properties.

.By means of our invention particles of dirt and metal are removed from thegrinding surface of the grinding wheel by coaction of the rotary abrading wheeltherewith whereby to clear'the recesses and pores in the grinding surface, and the partlcles or grams in the abrading surface are sharpened.

In order to maintain the abradin wheel at an angle with relation tothe grin ing wheel there a spline groove and key connection 81 between the shank 40 and the sleeve 36.

The shank passes through a slot 82 in the hood. A plate 83 normally closes said slot and is arranged to slide'laterally in a guide 84 on said hood. The plate is provided with'an outward bulge 85 in which there is a h0le'86. The inner end of the sleeve is received through said hole in said plate, and is ad justable axially in said hole by axial adjust- I ment of the sleeve in its bearing 35. .The sleeve normally closes said hole so as to prevent the passage of dust and dirt through The bulge accommodates the fork 51, the hood 52, and the abrading wheel and other parts mounted in the fork, throughout the various adjustments of the abrading wheel.

When itis desired to true or to dress the grinding wheel the sleeve36 is adjusted axially in its bearing 35 and in the hole 85 for approximately positioning the abrading wheel with relation to the grinding wheel, the sleeve being clamped in such position in said bearing, The hand-wheel is then turned for obtaining the proper contact between the abrading wheel and the grinding wheel. The grinding wheel being rotated byits usual v power drive causes rotation of the abrading wheel by peripheral contact therewith. The relative positioning, between'the abrading wheel and the grinding wheel causes a wiping action between the periphery of the abrading wheel and the periphery of the grinding wheel for truing and dressing the latter.

During such operation the abrading wheel is moved laterally across the width of the grinding wheel by manipulation of the handwheel 34, whereby the slide 29 and the abrading wheel 38 are shifted laterally on the hood.

This lateral shifting also causes lateral movement of the plate 83 in its guide, the plate throughout all its adjustments maintaining the slot 82 closed;

If desired, a composite abrading stub or pencil 91 made of composition similar to that of the abrading wheel may be mounted in a socket 92 in the inner end of a shank 1&0 and fixed therein by a set-screw 93. This stub or pencil may have a contour at its contact end [with the grinding wheel of suitable shape for imparting a desired peripheral contour to the grinding wheel, if it is desired to impart a shape to the grinding wheel other than cylindrical. Such an arrangement is illust-rated in Fig. 7 in which parts are shown similar to those above described but raised to the series 100.

Our improved device is simple in construction and operation and provides means whereby the dressing or truing of the grinding wheel may be quickly accomplished and dis- I penses with the use of expensive diamonds by Letters Patent, is:

which have been heretofore employed for the purpose.

Having thus fully described our invention,

what we claim as new, and desire to secure In a machine of the character described,

y the combination of a grinding wheel, a hood therefor, an ,abrading wheel operatively 1ocatedbetween said hood andsaid grinding. wheel, .a mounting for said abrading Wheel comprising a fork, a sleeve and a shank; said. fork fixed to the inner end of said shank, a guide-on said hood, a laterally movable slide on said guide, means on said slide for securrotative in saiddeeve for holding and main- I taining said fork and said bearing means for said abrading wheel at an angle to the plane of said grinding Wheel, means for adjusting said shank in said sleeve, said hood provided with a slot, and a cover plate for said slot having slide connectionwith said hood, said cover plate provided with an upwardly ex-,

I said shank, said angularly positioned fork, said-bearing means and said abrading wheel,

said cover plate movable laterally on said hood with said mounting, and said cover plate with its bulge maintaining said slot in closed relation throughout the lateral movements of said abrading wheel.

In testimony whereof, we have hereunto signed our names.

FERDINAND J HOHNHORST. FERDINAND J. KROEGER.

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