US1455213A - Dressing tool for grinding wheels - Google Patents

Description

.May 15,1923.

1". LARSSGN DRESSING TOOL FOR GRINDING WHEELS NJ. 1 I A 4 n? mil "Emma-as. uwmmsmw,

LwS/SEN, (333 WQRCESTEISL, ZKAQSEQZELL'EETEYS, ASSIEHEZ'UYr't KERESSI'NG T6631 "5 9E tit 15513533 G- i Application iii-e6. ite ptemhci:

To all whom in mm/ (IDs b86771.

Be it known that L THURE Lsuseoir. a citizen of the United States of America, siding at Worcester, in the county of Worcester and fiat-e, of iiiassachusetts, have invented certain new and useful improvements in Dressing Tools for rinding Nheeis, of which the following is a full, clear. and exact specification.

This invention is an improvement in dressing tools used for trimming grinding wheels.

The grinding wheels in most common use are made of abrasive grains, such as aiuminum oxide, held together by a ceramic bond, such as vitrified clay materiai, which has suiiicient arihesive strength to prevent rupture of the Wheel riuring rotation and to hold the surface grains in place for a time while grinding proceeds and yet is adapted to break away when the strain becomes excessive and permit new and unriuiied grains to he presented to the work. The procedure of shaping a wheel, during manufacture and after it has been used and its grinding surface needs renewing, is eased. on this fact that the bond is Weaker than the rgrairi. Hence, to dress a Wheel it is merely necessary to rotate the wheel. and exert sui'iicient pressure with a cutting too against the grinding surface to disrupt the top layer of bond and remove the exposed abrasive grains. For this operation, it is customary to use a dressing tooi or dresser mounted on suitable mechanism tor trarersing across the wheel face. One type of dressing tool which. may be used comprises a freely rotatable cup shaped or hoiiow conical disk which is forced against the .rheei and is rotated thereby. The combination of the pressure and the rolling action of the disk crushes the bond and trims the surface of the wheel.

Since the disk is ordinariiy rotated at a high speed and with great pressure against the Wheel, often exceeding 1000' pounds. the pivotai. mounting of the disk Wears away rapidly, this action being accentuated by the dust from the wheel which gets into all the hearings not thoroughiy protected. A frequent resuit of the enormous pressure put upon the disk to cause the riisk shaft to become welded toits thrust hearing. The excessive wear on the various parts soon pro-- duces ioose hearings, and prevents work of the best character being prociuceri. in fact, this operation. must often he carried on with 51, 1915, Serial il'o. extreine accuracy and. orir; tools precision work can her 'i For i 1 loosely mounted (iisir hie cause L1 the wheel and to cui? to V F or such reasons the 1 ot a rir. heretofore has been short anti the dre. ig wheels he" heen made because of the ne for re dressers frequent The object of the present invention is accordingly to provide a, dressing tooi character descriheri which Wiii not be subject to the diserirantages above s t which is correctly ciesircnei to Withstsi 7 t pressure and strains put upon it which is hearing members capable of quick anti es adjustment when compensation for the sins;

amount of wear taking; piece is necessary and.

which is dust proof for any eijusteci position of the hearings.

To the accomplishment oi this obiect anti such others as may hereinafter rphesr. Wili be readily understood by those skiiie in the art, the invention comprises the zene ai features and combination of here ina'ttcr described and more psrticuiariy pointed out in the appended cisirns.

The preferred embodiment inrem tion iiiustratcd in the accompanying draw-- ing, in which:

Fig. 1 is a horizontei section through the dressing tooi; v

Fig. 2 is a section on the iinc $3 Fig. 1;

is an enci eievatiou which in cross section. looking Efrem i Fig. l, the dust cap having removed; and, v

Fig. i is a detail viewer? one of the ingsaiijusting followers.

In 1. he practice of my invention. I have provided a dressing tool conu irising disk if herein illustrated as being of hoiiow c0r icai form. which is secured to the end 0 shaft 3.1 mounted. to rotate in a housing lit adapted to he a ijustahir iiizeri in piece on. by the usual strap and dressin mac-nine bolts. he disk is rigitiiy secured to the shaft by a screw-threaded bolt heri s? conica head which engage: the i. side or in disk and clamps securely sgeinst the end of the shaft.

It is apparent that Whe she against the grin. 1, i, with heavy pressure, resultant en" for the shaft 11 which are to take up the wear caused by the severe I 18 screwed into the bore.

side thrusts on the shaft are proportionately severe. In order that the disk may turn freely with the wheel, bearings are provided made adjustable character of the work soas to avoid the slit-- ficulties caused by loose bearings. In the embodiment illustrated, the front end of the tool is provided with an adjustable conical bearingwhich maybe an anti-friction hear-- ing comprising an inner raceway 15, rolls I 16, and an outer raceway T2. The outer raceway 17 is loosely engaged in an enlarged bore in the housing 12 and it is positioned longitudinally of the housin by a follower The inner raceway 15 surrounds the shaft 11 and abuts against a flange 19 formed integral therewith. It is evident that longitudinal movement of either of the raoeways will adjust the bearing. The outer raceway is adjusted by turning the follower 18 within the housing which moves the raceway 17 In order that the hearing may be conveniently adjusted, I provide suitable adjusting and locking mechanism. While I may utilize a construction such as emplo ed at the other end of the shaft, 1 preferab y provide means for tightening the bearings from outside the housing. Gne form of mechanism by which this may be accomplished is illustrated in Fig. 2 and comprises a worm 2O loosely engaged in a hole in a boss 21 formed on the housing 12. The worm is in operative relation with the follower 18 through engagement with generally longitudinal teeth 22 out on its threaded periphery. The worm 20 is held from longitudinal movement within its chamber by two set screws 24, one of which forms a thrust bearing for the worm when it is turned. When it is desired to adjust-the bearing. one of the screws 24 is removed and the worm is turned in a clock-wise direction by a screwdriver. Assuming all the screw threads to be right-handed, which is the preferred construction, the upper screw 24 would be removed to take up wear in the bearing, while the lower screw 24 would take the thrust of the WOKIIL, The screws 24 serve, when in place as shown in Fig. 2.

to lock the worm .a ainst accidental rota-.

tion and to exclude dust from the interior of the housing.

One feature of the invention relates to the construction by which the bearings are rendered dustproof within the housing. The front or cutter end of the tool is protected from dust by a stuffing box 25 and a dust cap 26. The follower is provided with a central recess to form. the stufiing box having the usual packing which is held toward the smaller and of the recess by a spring 27. The stufling box is closed by a gland 28 threaded on to a reduced portion 29 of the thrust bearing ween e follower. The gland is provided. with holes the housin 12. The dust cap 26 is mounted on the sha lt 11 and rotates therewith. The cap is threaded to receive the end of the shaft and the two parts are secured rigidly together by a locking screw 31. Since the adjacent surfaces of the dust cap 26 and the glands 28 are separated for clearance, have provided a dust cap construction adapted to reduce the liability of dust entering this interstice. This feature involves making an extended radial and preferably tortuous passage between the rotating cap and the stationary gland. -As shown, this construction may involve complemental annular flanges on the two parts, which are so ofi'set as to produce a. broken passage through which the dust must travel to reach the bearing. The shape and extent of the passage combined with centrifugal action make an effective barrier to the dust.

Theother end or the shaft 1']. is supported laterally by bearings adapted to take radial and end thrusts. My preferred construction involves a radial ball bearing 82 and an ad justable thrust bearing. The shaft reduced at 33 to accommodate the inner raceway 34 of the'bcaring 32 and again at 35 to accommodate a sleeve 36, of the thrust bearing. The movingraceway 37 of the thrust bearing is carriedbythe sleeve 36 while the fixed raceway 38nis--supported by a selfaligning annular 39 which is in turn supported against longitudinal movement by a follower 40 threaded into the housing 12. The inner member 34 of the radial bearing and the sleeve 36 of the thrust hearing are rigidly secured to the shaft 11 by a collar 11 and nut 42, as is clearly shown in the drawing.

It will be apparent that rotation of the follower 40 will take up the wear in the or move the shaft longitudinally if desired. As the rear of the housing is readily accessible, the worm actuator for the follower 18 on the front of the tool may lie-omitted ,if desired. ,As illustrated,

the follower 40 is adapted to be tui'ned by means of a suitable tool inserted in slots 49.

The follower 40 may be'j'provided with a locking device to prevent its accidental displacement. While I may utilize the construction described above; the locking is preferably accomplished by a key 43 which prevents relative rotary movement between the follower and the housing. The periphery of the follower is provided with a series of slots 44 (Fig. 4), six slots being a convenient number, spaced at suitable intervals, such as alternately 45 and 60 degrees apart. The interior ofthe cooperating "threadedportion of the housing has four similar slots 45 equally spaced. The slots are preferably sesame joint with the housing so that the bearings bearings,

at this end of the tool are thoroughly protected from dust. The bearings are lubricated by oil inserted through an oil hole closed by a screw 48.

Numerous advantages of a dressing 'tool having the construction set forth will be apparent to those skilled in the art The novel construction by which dust is excluded from the various bearings provides a tool which will run much longer without adjustment than those heretofore employed. have furthermore provided a shaft mounting which is adaptable to withstand the normall put upon it and which is readily adjusted to a correct condition. becomes necessary to take up wear in the this. may be done, without removing the tool from the dressing machine, by

strains removing one of the screws 24 to permit access to the worm 20 at end of the tool and by ca 46 at the other end.

aving thus described my invention, what I claim as new and, desire to secure by Letters Patent is:

l. A. dressing tool for grinding wheels comprising an open ended housing, a rotatableshaft mounted therein and having one end projecting therefrom, a cutting disk on the work-engaging unscrewing the dust the projecting, end, means to exclude dust form an abutment from the inside of the housing, adjustable radial bearings within the housing adjacent said projecting end of the shaft, radial bearings for the opposite end of the shaft, adjustable bearings forrreceiving end thrust only, and means for positively adjusting each set of said adjustable bearings independently of the other set to take up radial and longitudinal wear.

2. A dressing tool for grinding wheels having in combination, a housing-provided with a series of slots, a freely rotatable shaft. a work-engaging disk mounted thereon, an antifriction bearing for the shaft comprising a pair of raceways, a follower threaded into the housing and arranged to for one of the raceways, said follower being provided with cooperating slots, and a key to lock the follower in adjusted position when inserted in said slots formed in the housing .and the follower;

.3, A dressing tool for grinding wheels When it having in combination, a housing having open ends, a shaft therein, a work ging disk mounted on the shaft, n thrust'bearing near one end of the housing, adust cap to close said end of the housing, a conical roller bearing near the disk, a follower threaded into the housing to adjust the bearing, a stufiing box between thadisk and the bearing, a gland threaded-on to the follower. and forming one member of the stufiing box, and a cap fixed on the shaft adjacent the gland, the adjacentsurfaces of the gland and the cap beingcomplementallv offset to form atortuous passage from the periphery toward the-center.

4. A dressin tool for grinding wheels having in-com ination, a housing, a shaft hating a shoulder, a work-engaging disk mounted on'f'one end ofthe shaft,a radial bearing abutting the shoulder, a thrust hearing abutting the radial bearing, means for clamping one member of each bearing against the shoulder and a follower engaging the other member of the v and having a threaded engagement with the housing. i

5. Ina dressing tool for grinding wheels, the combination of a housing, a shaft rotatably mounted therein, a cap to enclose one end of the housing, cured to the shaft at the opposite end of the housing and an annular dust cap threaded on to the end of the shaft and counterbored on one side to receive a part of the disk and having a dust excluding flange on the other: side.

6. A dressing tool for grinding wheels comprising 'a housing, a rotatable shaft mounted within and projecting from' one end of the housing, a cutting disk on the outer end of the shaft, radial and end thrust bearings for. the shaft, a dust cap surrounding the shaft and means associated there-.

with for excluding dust from the bearings and means for adjusting a bearing from thrust bearing.

a work engaging disk sea shaft mounted with- .Signed at- Worcester, Massachusetts, this 4th" day-ofsept, 1918.

Y THURE masses.

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