US1827967A - Truing mechanism for grinding wheels - Google Patents

Description

@ct 26,1931. w. LE BRYANT 1,827,967

TRUING MECHANISM FOR GRINDINQ WHEELS Original Filed July 20, 1921 6 Sheets-Sheet 1 Oct. 20, 1931. w BRYANT 1,827,967

TRUING MECHANISM FOR GRINDING WHEELS Original Filed July 20, 1921 6 Sheets-Sheet 5 Oct. 20, 1931. w. LE R. BRYANT v TRUING MECHANISM FOR GRINDING WHEELS Original Filed July 20, 1921 6 Sheets-Sheet yflganl 42 2%. I

Oct. 20, 1931. w. LE R. BRYANT "TRUING MECHANISM FOR GRINDING WHEELS Original Filed July 20, 1921 6 Sheets-Sheet 5 NNM MMN NMN .Oct. 20, 1931f. w LE R BRYANT 1,827,967

" TRUING MECHANISM'FOR GRINDING WHEELS Origifial Filed July 20, 1 21 aspeets-sfieet .6

Patented Oct. 20, 1931 man STATES PATENT OFFICE 1 WILLIAM LE ROY BRYANT, OF SPRINGFIELD, VERMONT; BLANCHE B. BRYANT, OE SPRINGFIELD, VERMONT, ADMINISTRATRIX F SAID WILLIAM LE ROY BRYANT,

nncnen TRUING MECHANISM FOR GRINDING- original applicatlon filed July 20, 1921, Serial No. 486,080. Divided and this application fllcd December 26, 1925. Serial No. 77,837.

This application is a division of my. a pli-v cation entitled Grinding machine, erial No. 486,080, filed July 20, 1921, upon which Letters Patent No. 1,575,968 were granted March 9, 1926. The invention relates to improved mechanism for truing grinding .wheels which may be used in conjunction with the grinding machine described in the above mentioned application, and in which a has hitherto been possible. An object of the invention is to provide for a relative reciprocation and transverse feed of the truing mechanism of the grinding wheel, in which one of the instrumentalities is mounted to move toward the other about a fixed center. Other objects of the invention are to provide template or control bars which are interchangeable and adjustable so that the accuao rate truing of the wheels is not dependent upon the skill of the operator; and to providefor accurate truing of grinding wheels of difierent shapes, including those wheelswhich have portions which vary in diameter. In the drawings,-

ing machine such as is described in detail in my above mentioned Letters Patent. No. 1,575,968, and in which may improved truing mechanism is incorporate Fig. 2 is a fragmentary end elevation of the upper portion of the grinding machine, which includes the truing mechan sm;

Fig. 3 is similar to Fig. 2 but shows the opposite end; p

Fi t represents a section through the grin ing wheel on a vertical planetransverseto the machine, and illustrates the truing mechanism in operating position;

Fig. 5 illustrates a template or control bar for the truing mechanism, and the mechanism by which said control bar is adjustably and removably supported;

Fig. 6 illustrates in perspective "and on an 99 of Fig.5;

better and more stable control is eflected than V Fig. 1 represents in front elevation a grindenlarged scale a'portion o'f the bar shownin Fig. 10 re resents a vertical transverse section on the line 10-1O of Fig. 1;

Figs. 11 and 11 together represent a longitudinal section on the line 1111 of Fig. 10, all on a larger scale;

Fig. 12 is a section onthe line 12--1'2 of Figure 11;

Figs. 13 to 16 inclusive represent diiferent of the invention as defined in the claims, that the phraseology hereinemployed is for the purpose of description and not of limitation, and that the drawings are more or less conventional.

. Proceeding to adescription of the illustrated machine,'50 illustrates a hollow bed having suitable front, rear and end walls. On

the upper face or table formed by the bed there are two upright end standards 51, 52,

which at their upper ends support two parallel bars 53, 54, one of which sup orts a truing mechanism and the other 0 which.

sup rts the work-holding and rotating' erably the arms 55, 56 are cast in hollow form Y for the sake of lightness, and they are clamped.

to the bar 54. The upper ortions of the arms may -be split-and provi ed with clamping screws 59'. Asa result of this construction, thew'ork carrier, by loosening the clamp screws59, may'beadjusted longitudinally of the bar 54" and then clamped 'rlag'idly thereto, so'that, by moving the bar-.axi ly, the work carrier may be moved therewith. By mechanism, which I shall subsequently explain, the

bar may be moved manna 1y or automatically in an axial direction for the purpose of ef-.

tapered bushings 60, 61, in which the bar 54' is journaled and in which it may be moved longitudinally. These tapered bushings may be adjusted to compensate for wear by nuts 62, 63, abutting against the inner faces of the uprights. By mechanism, subsequently to be explained, the work carrier and its supporting bar 54 may be swung about the axis of the bar 54 for the purpose of advancing the work .to and withdrawing it fromthe grinding wheel.

The grinding wheel may be of any desired shape according to the work to be ground. In the form shown in Fig. 14, it comprises three abradin members 91, 92 and 93, which may be of di erent' kinds of grinding material, if desired. These may be provided with spacing and clamping members of any convenient type to secure them to a shaft for rotation.

Although a driving pulley may be mounted directly on the shaft 65 to drive the grinding wheel, I prefer to avoid the resulting bending stresses on the shaft due to the lateral pull of the belt on a pulley, which stresses cause morerapid wear on the shaft bearings. A shaft 115 is therefore mounted coaxially with the shaft 65 and is connected thereto-by a suitable universal joint as shown and described in Letters Patent No. 1,575,968. A pulley 114 is mounted on the shaft 115 and driven from any suitable source of power, as by a belt 113.

The grinding wheel is also preferably mounted in such a way that it can be adjusted with its carrier 66 towards or from the work By inspection of Figure 10, it will be observed that the work carrier depends normally from the bar 54 in front of the grinding 'wheel. The movement of the work, which is carried by the work carrier, is in a curvilinear path towards or from the grinding wheel,

. swung 9. out its axisto efi'ect a feeding move:

iment of the work towards the grinding wheel or its withdrawal from grinding position.

parallel to the axis;

carrier, as by rotation of an abutment screw 5 68 The work carrier may be reciprocated lon gitudinally of the work axis, and thus lon itudi-nally of the bar54 whose axis is paral el to that of the work axis, so s to effect an axial movement of the work while it is in engagement' with the grinding wheel. In some cases, however, it is not desirable to have this Fig. 11*, is provided with rack teeth 162 which extend part way around its periphery. With the rack thus formed, there is engaged a pinion 163 secured on a shaft 164 journaled in a block 165 into which, the-end of timber 54 projects. The end of the shaft 164 is angular 1n cross section, as shown at 166 in Fig. 3, so that, by applying a wrench or handle thereto, the pinion 163 may be rotated in one direction or the other to move the bar 54 longitudina-lly of itsaxis, the blockin the meantime being held a ainst movement. I also provide means by w ich the block itself may be rocked or reciprocated back and forth to effect the automatic longitudinal reciprocation of the work carrier. To accomplish this result, an arm or lever 167 ispivoted on a pintle 168 mounted in lugs 169 projecting from the upright 52 of-the' frame. This lever or arm 167 is rovided with an upwardly projecting yoke 1 0 which embraces a pin 171 inserted in the block 165 and located almost directly above the pintle 168. Consequently, by rocking the lever 167 about the axis of the pivot or pintle 168, the block 165 and the bar 54 may be reciprocated. The lever 167 is automatically oscillated about its axis by any suitable mechanism driven from the main power shaft. As described in Letters Patent,

No. 1,575,968, such mechanism is preferably provided with a clutch device such that when the operating handle is'operated to disengage the clutch, the latter will remain-in engagement until the work carrier reaches the right hand end of its movement as viewed in Fig. 1. This is desirable particularly when shouldered work is being ground as the larger grinding wheels are to the right of one facing the machine. It isfurthermore desirable because, as will be subsequently explained, the work carrier carries the control template or bar which governs the action of the truing mechanism on the wheel, and it is also desirable that the work carrier should be stopped always at the same point in truing the wheel for any particular grinding operation.

For efiecting a relative transverse feed of the work and the grinding wheel, I employ a single speed automatic feed mechanism by Y which the work and the grinding wheel are I brought into grinding relation and continued in that relation until the Work has been reduced to the desired diameter, after which the work and the tool are separated, whereupon the feed is automatically discontinued. Provision is made, however, by which the operator may manually effect a feeding or withdrawing movement of the movable element. The transverse feeding mechanisms act through a slide 198 which is mounted on the bed of the machine and against an end of which rests a guide bar or template 197 mounted on a dependent portion 196 of the longitudinal member 57 ofthe work carrier. Since the work carrier is pivotally swung on an axis, the slide 198 acts as an adjustable stop to limit the outward swin of thework carrier away from the grinding wheel.

For the reciprocation of certain parts of the machine, such as the sliding shaft 228,

fluid-actuated pistons maybe provided whichcan be readily controlled b suitable valves.

Any suitable source of flui pressure may be used. With my grinding machine I have provided a pressure system comprising a reser-.

voir 240 for fluid, and a rotary pump, the casing of which is indicated at 242, from which conduits are led'to the various pistons and control valves. vided to prevent excessive pressure in the supply conduits." Thi's'pressure system as well as the other parts of the machine, which have been mentioned are fully described in Letters Patent No. 1,575,968, previously referred to.

The present invention involves one of the salient features of the grinding machine, that is, the truing mechanism for the grinding wheels. The dressing tool is mounted in a swinging arm which is normally in inactive position but which may be swung downwardy so as to bring the dressing tool into operative relation to the grinding wheel. The

dressin tool is indicated at 300 and it is adjustablyclamped in a swinging arm 301,

the hub 302 of which is rigidly secured to the p bar 53, to which reference has previously been made. This bar is'adaptedto oscillate in bushin s 303, 304,'placed in hearings in the uprig t standards 51, 52, and is also I adapted to slide therein. To protect the bearings, thevvbar 53 is provided with two sets of telescoping sleeves, 305, 306. In each case, the sleeve 306 is screwed into the thread-' ed a erture in the upri ht or standard, and

the s eeve 305 can slide ack and forth with the bar 53. At one end, the bar 53.has a weighted arm 307 keyed thereto,'and between the hub of this arm and a shoulder 308 on the bar there is placed a second Weighted lever 309. The hubs of these two levers have spaced shoulders 310, 311, adapted to engage I 'when'onehas moved to a limlted extent relatively to the other. Normally, when the dressing tool is not in operation, the weighted Belief valves are also pro- -forms a arms 307, 309 hang downwardly and hold wardly and upwardly until it reaches the position shown in Fig. 4, in which position the dressing tool is engaged with the grinding wheel. The bar 53 may now be reciprocated under the control of the operator. Any suitable mechanism for effecting its reciprocation is-employed, but preferably, inasmuch as I employ other mechanism which is controlled by fluid pressure, I also utilize.

this pressure for moving the dressing tool bar. To this end, a casing 312 is screwed to the hearing at the upper end of the upright- 52. The end of the bar 53 is enlarged to form a cylinder 313, the inner end of which may be closed by a plug 314. A stationary piston 315 is located in the cylinder thus provided and a stationary extension or piston rod 316 extends through a stufiing box located i-n'the head 317 at the end of the cylinderr The outer end of this piston rod is screwed into the end of the casing 312. Conduits 318, 319 extend through the piston rod, the former connecting with the lefthand end of the cylinder and the latter connecting with ther-ighthand end of the cylinder, as best shown in Fig. 11.-- When the fluid is delivered through the conduit 318, the piston being stationary, the entire bar 53 is moved to the left, and, of course, when fluid is delivered through the conduit 319, the bar 53 is moved to the right so that the dressing tool may be caused to traverse the face ofjthe grinding wheel. Suitable pipes-320, 321 connect, the conduits 318,1 319, respectively, with a valve mechanism contained in the casing 326 and fully described .in Letters Patent No.

1,575,968. 'A handle3a 0 is attached to the valve, by manipulation of which the operator may move the valve in one direction or the other to cause the corresponding movement of the bar 53 and the dressing tool carried thereby. I

When the truing tool is operating on the grinding wheel, it may be guided in any desired path b the use of a control bar or template which is preferably supported on the work carrier. Referring now to Figures 4to 8, and 10, it will be noted that, on the front side of the longitudinal bar 57 which ortio n of the work carrier, there is an uprig t longitudinal flange 350, and in the angle formed Jay this flange there are secured two blocks 351, 352, which constitute portions of afholding mechanism for the control bar or template. In these blocks there are arranged two center pins 353, 354. The block or holder 351 is split" so that the center pin 353 may be clamped in place by the screw 355 after the center pin has been ad usted to proper position. The center pin 354 is seated in a socket in the holder 352,

which is also split (as shown in Fig. 7) so that the split portions may be drawn to ather by a screw 356 to clamp the center pin. K spring 357 is seated in the socket and bears against the shoulder on the center pin,-

as best shown in Fig. 5. By slightly loosenplaced in the holders and locked rigidly in place-so as to guide the dressing tool arm as it is reciprocated axially of the bar 53. The control bar may be straight, shouldered, convexly or concavely curved, or tapered, as may be desired. Preferably, although not necessarily, it is circular in cross section. I have T shown in Fig. 5 a control bar which is indicated at 359 and which has centering recesses 360, 361 at its endsto receive the center pins 353, 354. The ends of the control bar rest onflat faces v362, 362 (shown in -plan view in Fig. 5) on which the center pin holders351, 352 are secured, and the'sides of the end portions of the control bar rest against abutment. screws 363, 364, which are passed through theflange 350 of the work carrier. The abutment screw 363 has a relatively coarse thread and it is locked in position by a set screw 365. The screw 364 has a fine thread and is screwed into a threaded sleeve 366 inserted in a flange 350. The end of this screw has a knurled head 367 by which ll3 may be rotated. In practice, the center.

pin 354 being drawn to the right in Fig. 5, the control bar is placed in position as shown, so that its ends rest on the flat faces 362 and its sides against the screws 363, 364, after which the center pin 358 is released by the operator and is forced by its spring into engagement with the socket 361 at the end of the bar. Each end of the bar is thus engaged by a three-point bearing and is held accu-.

rately in position. The clamping screws 355, 356 may e set tight to hold the center ins in position. Ordinarily, the pressure 0 the spring-357 is suficient tocause the center pins to grip the control bar and hold :it accurately in position without tightening the clamping screw 356. The. holding mecha 80 nismior the control bar ifs'capable \of an exceedingly fine adjustment without distort- 'ing the control bar. The swinging arm301 which carries the dressing tool 300, is forme at its end with a bearing, 369in which a thrust pin 368 -is arranged so that'the end of the thrust pin may project beyond the arm' and be brought against the rear side of the 'control bar'359, as shown in Fig. 4. The arm is of such length that it can be swung over or past the control bar, and, to permit this, the pin 368 must be partially with drawn so that its projecting end is substantially flush with the end of the arm. The pin is provided with a knurled head 370 which may be grasped by the operator for this purpose. The bearing for this thrust.

pin is split, as shown in Fig. 2, and a clamp ing screw 371 may be used to draw the portions of the bearln together to clamp the thrust pin in either 1ts advanced or retracted position. When the operator desires to dress the grinding wheel, the arm 301 is moved from the position shown in Fig. 3 forwardly and downwardly, and the thrust pin 368 is retracted to permit the arm to pass the control bar 359. Thereafter the operator forces the thrust pin downwardly so that its end engages the rear side of the 'control bar, as

showninFigure 4. When in this position the counterweight 309 presses the thrust pin to be reciprocated, whereby the dressing tool traverses the face of the grinding wheel. The control bar corresponds to the shape of the finished work so th t the wheel is dressed to impartthat shape t a new piece of work. For example, in Fi s. 13 to 16 inclusive, I have illustrated di erent pieces of work, and the control bars for dressing the wheels, by which these pieces of work are finished, correspond to the pieces as illustrated.- Where the grinding wheel consists of several sections WhlCll vary in diameter, as, for example, in Figure 14, there are shoulders between the several sections, and the thrust pin on the dressing toolar'm could ,not slide back and forth on the shouldered control bar. I

ures 5 and 6, I have shown the control bar 368 against the control b r '359. The opv low as being provided with the three different diameters a, Z) and '0, separated by the shoulders d and e. In the smaller section 0 and in. the intermediate section b, I introduce ins 372, 373, which are semi-cylindrical. he end of each pin is flush with the next sectionof a larger diameter, but it is also provided with inclined faces 374, 374, by which the end of the thrust pin may be guided from the for example, to t e next section b for example, and thence to the section a. To aceriphery of one section c 'compl'ish this result, assuming that the thrust pin. 368 is moving to the left in Figure 5,.1t continues this movementuntil by hand, rotates the control bar about its axis thrust; pin and thus ,th rust 'it rear-wardlyifar enough until itv can rideon thesections of thecontrol bar. The thrust pin then continues-its movement to the left untilit engages the shoulder d, Iwhereupon the eperator againrocks the, control bar to bring the pin 37 3 under the thrust'pinand again swing the thrust pin rearwardly farenough until it can ride on the section ,a. When the thrust pin is moving in the oppositedirection or to the right, it may drop oil" of theshoulder to the nex-t diametrically smaller section without doing any damage. It'will be remembered that thedressing tool bar 53 is moved by fluid pressure from the pump, but, inasmuch as the relief valve mechanism previously described is included in the hydraulic system, the thrust pint-368 may engageone of the shoulders '11 or e and be arrested with- .out damage. A very decided advantage'is thus. achieved by the employment of a yieldingl'mechanism for operating the dressing too Having said invention and described a way, ofmaking and using the same, although without attempting to set forth all of the forms in which-it may be made or all of its modes of use, what I claim is:

- 1. A grinding machine comprising a bed,

a grinding wheel, a bar journaled in the bedvparallel with the axis-of the grinding wheel, a dressing ool'carrier hung on said bar. and having an inoperative position above said wheel, said carrier being movable forwardly and downwardly about the axis of said bar from said inoperative position to bring the dressing tool into engagement with said-wheel, and means for moving said tool carrier lengthwise of the axis of said bar.

2. A grinding machine comprising a bed, a grinding wheel, an arm pivoted at one end to swing about an axis substantially parallel to the axis of the grinding wheel, said arm having adjacent its other end means for bolding a dressing tool, means for moving-said tool carrier lengthwise of its axis, and a template engageable by the tool-holding end of said arm, said template extending parallel to said axis and held against longitudinal movement along which said arm may slideior controllin'g the pivotal movement of said arm.

' 3. A grinding machine comprising a bed, a grinding wheel, an arm pivoted at one end to swing about an axis substantially parallel to the axis of the grinding wheel, said arm having adjacent its other end means for holding a dressing tool, a template engageabl by the tool holding end of said arm, said plate being arranged parallel tg said. a controlling the pivotal movement 0 lengthwise of its axis, a template for-controleffecting a relative movement of said wheel and template in lines transverse to the, axis thus described the nature of mytoward and from said wheel, whereby the'acbe engaged, when swung into downward ac- 9. A grinding machine comprising a bed, a

temis for saidlcairrir 'with'saidworlz carrier,"-and-=means [4,, A grinding maf h'ne .v r m i i e a grinding. wheel, a pivoted dressing tool carrier movable about an, axis subst-a tially parallel to the axis of the-grindi wheel to present a tool against. the periphery/of said wheel, means for moving said tool carrier ling thepivotal movement of said tool carrier and hence the distance of the tool from the axis of the wheel, and mechanism for of said wheel, whereby the template-controlled distance between the tool-and theaxis of the wheel may be modified. r 5.'A grindingmachine comprising a bed,

a grindin wheel, a pivoted dressing tool carrier mova ble about an axis substantially parallel to the axis of the grinding wheel to pre sent a tool against the periphery of the wheel, means for moving vsaid tool carrier lengthwise .of its axis, a template for controlling the pivotal movement of said tool carrierand hence the distance between the tool and the axis of the wheel, and manually-operated feed mechanism for feeding said template tion of the template may be modified without alteringitsshape. Y

6. Agrinding machinecomprising a bed, a grinding wheel thereon, a dressing. tool carrier pivoted to the bed, counterbalancing weights connected to said tool carrier for holdingit normally in a raised inactive position, and mechanism'normally .clear of said.

tdol carrier with which said tool carrier may i tive position,'for feeding a tool carried there-- by to the grinding wheel.

-7. A grindi g machme comprising a bed, a grinding whe'el thereon, a work carrier, a dressing tool' carrier pivoted to the bed and swingable topresent a dressing tool against the periphery of said wheel, and means for engaging the free end of said tool carrier with said work carrier to hold 'said tool in operative position against said wheel.

' 8. A grinding machine comprising a bed, a

,grinding wheel thereon, a dressing tool car rier pivoted to the bed, 'a work carrier pivoted to the bed and adjustable toward and 0 from said wheel, and means for guiding the tool carrier comprising means for engaging the tool carrier with said work carrler.

grindingwheel thereon, a dressing tool carrier pivoted to the bed, a work carrier plvot ed to; the bed'and adjustable toward and from said wheel, means forguiding the tool carrier comprising means for 'engagingthetool sition out of engagement with said template, a

and means for causing relative movement between the tool carrler and template longl- .tudinally of said axis.

11. A grinding machine comprising a bed, a gr nding wheel thereon, a dressing tool carsaid control bar or template and for sliding I along said control bar or template.

17. A grinding machine comprising a bed, a grinding wheel supported thereon, a relatively stationary control bar or template ,cx-

tending across the face of said Wheel, an arm rier pivoted to the bed for support and torn pivoted to said bed so that its free end may movement toward and from said grinding wheel, a template extending parallel to the pivot axis. of said carrier. means for detachabliengaging said carrier with said template, a carrier pivoted to said bed on an axis parallel tothat of said tool carrier and independently ofsaid tool carrier, support for carrier pivoted to the bed. for support and for movement toward and from said rindingwheel, a template extending parallel to the pivot axis of said carrier, means for de-'.

tacha-blv engaging said carrier with said template. means for-reciprocating said tool.-

carrier endwise of said template, a carrier movablv'supported bv .said bed, independently of said tool carrier support for carrving said template. and feed mechanism for said template carrier.

13. A grinding machine compr sing a bed. a grinding wheel. a work carrier pivoted to move toward and from the grinding wheel.

ing the tool carrier past said shoulders. said bar being movable to engage one of said faces with said tool carrier when the latter is in engagement with the adjacent shoulder.

be engaged with and disengaged from said control bar or template, and a dressing tool fixed in said arm for engagement with said face of said wheel.

18. A grinding machine comprising a bed, a grinding wheel supported thereon, a relatively stationary control bar or template extending across the face of said wheel, an arm pivoted to said bed so that its free end may be engaged with and disengaged from said control bar or template, a dressing tool fixed in said arm for engagement with said face of "said Wheel, and means for moving said arm lengthwise'of its pivotal axis.

19. In a grinding machine, a shouldered grinding wheel, a dressing tool carrier movable across the faces-of said wheel and toward and from the same, a shouldered control bar along which sa1d carrler 1s movable, yielding means for moving sa1d carrier along sa1d a dressing tool, a template engageable by the 1.

tool-holding end of said arm and arranged parailel to said axis for controlling the pivotal {movement of said arm, and means for moving relatively sto said said arm longitudinally template and said wheel.

In testimony whereof I have afiixed my signature. WILLIAM LE ROY BRYANT.

15. In a grinding machine, 1 a grinding wheel, a movable dressing toel -carrier. and

' a revolvable shouldered control bar or template. with which .said carrier. may be engaged and along which it may be moved, said'

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