US2115678A - Grinding machine - Google Patents

Description

April 26, 1938. A. G. BELDEN A GRINDING MACHINE Filed Oct. 7, 1935 2 Sheets-Sheet 1 WAX/nw 3 m W, m m u M L ww xl E Y 5 w u 3B 7 l.. E 4 4 m a G., 5% M f 4 /w 6 Ll A 4 v u wf |\I\/l4 .1| Z/ M, 4 4 s a a 06 f a mmm 5 sa af 6 K ,A ,P d m 5 u Z N J m w 0 m e w u. una". l

April 26, 1938. 2,115,678

A. G. BELDEN GRINDING MACHINE Filed Oct. 7, 1935 ZfSheets-Sheet 2 unsuuununnununn ALBERT EBELpEfv einem am, ze, iste I andere inciden, Worcnter, ida-sn designer to iiiorton (Continent, Worcester, cotnoin tion oit inniication dietetici" i?, lidiiii,

ti @intenso Tire invention relates to grinding ninciiines and ndtii regard to its more sneeiiic features to a sinu ingr niecllnnisni tliereior.

@ne object ot tlie invention is to provide an 5 electric siting device tvnose sensitiviinr is not an i'ected by arcing. Another oniect oi the invenm tion is to provide a sizing device candide of drie adjustment. Another oniectoi tite invention ie to provide an eidicient and sensitive cross ieed and.

lo control thereof for a grinding machine. @tirer objects will ne in nai-t obvious or in nnrt pointed ont hereinafter.

'tire invention accordingly consists in the tea titres oi construction, combinations ci elements, and nrrangenients of parte as vrili'iie eiieinniiiied in tite structure to loe hereinafter described, and tite scene of tine application of vvliicii will loe indicated in the following claims.

in tite accompanying dravvinns, in Wliicti is sncvvn one of various possible embodiments oi the mechanical features oi the invention,

itin. i is a View, partly in cross section and nartlvr in elevation, showing the hydraulic actuating and control mechanism for the cross feed siide oi" a grinding machine, and illustrating also certnin narts oi tine caiinering rnecl'oanisni in elen vntion,

itin. is a nian vien' ot the caiinering controL l" is a sectional View taiien on tite line Cim-d l', k l i i is a wiring dian'rnni iiinstrnting aise cer tnin detniis ci' tiie onticei an attrs. :iii lll i ie a n nine including a inni iii inu i T ivevc1 erinnert oi ii Worin tats-ie toet; ior tine snr. t and rota i ot' a Wort. .l 2 it Winicti is to ne erteriorijv gronnd. 'i'ie ein ents inst referred to which are not siiovvn in in are oi Welt understood construction and any desired ineens .tor noiding and rotating a I ivorir niece may tie ernnioved, whether suon ein J oodies means for longitudinally reciprocating the nforii niece or not.'A

ivionnted on time usual cross feed slidewavs, not snovvn, is a cross slide it oi any usual or desired iorrn, 'which journals in journals iii the spindle it oi? e, grinding wheel it. grindingl wheel l5 is a wheel guard it which, according to thisenibodiment of the present invention, forms a 4support for the Work calipering mechanism to be described.

Surrounding the I provide a Work; contacting calipering apparay demini idoi. fi-'iiiltitt tds Wiiicli may taire tile torni of that disclosed in tire patent to No. 1,992,027; for example comprising n feeler rod iii siidably mounted in a cnsing; to vvnicii is integrally attached an anvii provided with an adjustable contacting screw dianietricaiinr onnosed to and aligned with the end of teeler rod it, tneanvii member iid having also anotiier adjustable contact screw it arranged to near iaterailv noon the Worn and maintain the end o tine i'eeier rod iii and screw td in time desii-ed locationn in order to facilitate precise measurement with this caiinering device it mayl ne snlonorted in env convenient manner so that tine weight oi tite cesing it and the parte assemliied tnerevvitii not supported by the teeier rod di. To acconiniisli this there 'is provided a lintJ Wilton may ne clamped in any convenient position on n rod il nnrlsing from a bracket td attached to the tviieelguard it; tinus the parts oi tine cniipering mechanism are located in fixed position relative to tne grinding wheel yand traverse of the Work niece-if such is provided for, does noty in this preferred embodiment of the invention, alter the alignment of grinding vvheei and calinering device.u in case such traversing ineenanisin for the vvorlr table is provided the caiinering, ineciianisin is traversed relative to the vvorlt piece lout eine to its carefully balanced condition suon trnversing does not affect its operation and it is at all tintes measuring that part of the Worin: vri'iicii is being ground. iiovvever, it siionld ne rstood tire annaratns oi" the present in ven on is also narticniariy adapted tor in a inaciiine grinding by the .so-'called i n 3 ont inetnodg in iii-nich tiie Wheel in is ted in against tide worin niece il and ginds tiiont relative recinrocation between i wort: or, in sorne cases, tvitii entr a tive recinrocatory niotion vvticn nia-5r be nc in tire tviieei spindle it itself.

reterring to Fig. i, a iinl titl is loivotnilv7 and frictioinliiy1 supported on the lint: it (which is rigidly secured to the rod il) and the t'riction at nin di connecting linlis it and iid is such that tire iinii: may oe moved about its pivot by the operator out will remain in the position in which it is set. Pivotally mounted on the end of lint; td by means oi an enlarged portion 32 is a platform dd which has attached to it the casing t2, and thus the casing 22 is supported. Connecting a pin 3d which joins the link 30 to the platform it, and an ear 35 on the casing 22, is a spring 36 which maintains screws 24 and 25 in frictional Contact with the Work, thereby supporting the dit.

dit

caliper and providing a free sliding action of the feeler rod 2|.

Upstanding from the platform 33 are a pair of journal bosses 48 pivotally supporting a shutter member 4| which is in the form of a bell crank lever having a short arm 42 in contact with the" top of the feeler rod 2|. From inspection of Fig. i it will be seen that the upper or operating end of the shutter 4| will move through a substantially greater distance than does the feeler rod 2| pursuant to reduction in size of the work piece. Thus the mechanism so far described constitutes a contacting feeler calipering device together with mechanical amplifying mechanism, and in so much as the shutter 4| is utilized to cut one or more beams of light it may be of very light construction and thus themechanical apparatus of the calipering and control mechanism is subjected to very small strain which measurably increases its efficiency. One of the features of advantage of the present invention resides in the simplicity of the mechanical elements which, nevertheless being mechanical are highly reliable. Another feature of the invention associated with the foregoing is that adjustments for intermediate and final size may be made on the non-moving parts of the apparatus thus relieving the movable elements of the feeler mechanism from excessive load yand back play or lost motion incidental to an adjusting mechanism; while the invention permits adequate fineness of adjustment through the use of substantial and rigid adjusting mechanism associated with the parts that are not directly moved by the feeler.

Still referring to Fig. 1 attached to the upper side of the wheel guard I6 is a bracket 45 having, as better shown in Fig. 4, horizontal slideways 46 for the support of the dovetailed portion 41 of a slide 48. Referring now to Fig. 3, upstanding from the slideway 46 is a collar member 49 which positions a screw shaft 50 having a hand wheel 5| on the end thereof. The screw 58 passes through an internally threaded portion 52 of the slide 48. Thus the slide 48 is mounted for horizontal adjustment fore and aft upon the bracket 45.

Referring now to Figs. 1 and 2, the slide 48 has a depending slideway member 55 in which is a slideway 56 supporting a vertical slide 51 having a dovetailed portion 58 fitting in the slideway 56. A collar 68 attached to the depending portion 55 positions a screw shaft 6| having a hand wheel 62 for vertical adjustment, the screw shaft 6| passing through a threaded portion 63 in the vertical slide 51. Still referring to Fig. 2, attached to and projecting horizontally from the vertical slide 51 are a pair of platforms 65 and 66 separated by a slot 61.

The shutter 4| is located in the slot 61 between platforms 65 and 66. Referring now to Fig. 1, in this particular embodiment of the invention the shutter 4| has a pair of shutter arms 18 and 1 I, which successively uncover light beams, the first of which initiates a change in the grinding cycle and the second of which determines the grinding operation and is the final size control. The apparatus herein described may be readily set up for either the shutter arm 18 or 1| to control the final size but by way of a preferred example it may be considered that the arm 18 alters the grinding cycle while the arm 1| controls final size. Still referring to the upper part of Fig. 1, it will be observed that the slide 51 maybe moved up and down without great effect upon the righthand edge of the shutter arm 18, which is the edge which uncovers the light beam, while movement up and down of the slide 51 definitely alters the position at which the other light beam is uncovered by the shutter arm 1|. On the other hand, the relative position of both shutter arms 18 and 1| may be adjusted by turning the hand wheel 5| and thus moving horizontally the slide 48, and such adjustment does 4not affect the interval between uncovering of the light beams. Further, it may be stated that movement of the slide 51 pursuant to turning of the hand wheel 62 does change the interval between uncovering of the light beams. These features are due to the provision for adjusting the platforms 65 and 88 in two dimensions, as well as to the shapes of the shutter arms 18 and 1|, the right-hand edge of one of which is nearly if not quite vertical and the right-hand edge of the other of which is at all times substantially inclined to the vertical. By selecting the left-hand shutter arm 1| as that which controls final size the invention provides in effect a Vernier mechanism, for coarse adjustments may be made with the hand wheel 5| and fine adjustments with 'the hand wheel 62.

A feature of the invention is the control of the grinding operation by uncovering successively a pair of beams of light which operate a photoelectric apparatus ultimatelyy actuatingsolenoids to effect the desired control. Considering now the optical apparatus, its position, and general characteristics are indicated in Fig. 2 while more details of construction are disclosed in Fig. 5. Referring to these figures, I provide a lamp box 88 in which is located an electric light bulb 8| which may be of the point of light type or of the ribbon filament type in order to produce a beam having as little stray light as is possible Within practical limits. Box 88 has a pair of walls in which are inset semi-convex lenses 82 and 88 respectively. In front of the lenses 82 and 83 are semiconvex lenses 84 and 85 thus producing, as shown in Fig. 5, a pair of systems of condensing lenses. The outer lenses may be adjustable in telescoping supports 86, 81.

By the apparatus so far described a pair of converging light beams 88 and 89 are formed. These light beams are directed through concave lenses 88 and 8| to produce beams 92 and 83 of parallel or nearly parallel rays. In certain respects it is an advantage to avoid absolute parallelism as the beams of light may be desirably made very narrow indeed at the position Where they are intercepted by the shutters 18 and 1| with resulting sensitivity of the apparatus. The concave lenses 88 and 9| may be adjustably mounted in brackets 84 and 95.

The beams 82 and 93 are converted into beams parallel to each other by means of mirrors 86 and 91 which may be angularly adjustable for the proper setting-up of the apparatus. 'I'he beams 92 and 93 thus reflected pass across the opening 61 and through orifices |88 and |8| in a diaphragm |82 which otherwise protects photoelectric cells |83 and |84. Fig. 1 shows the orifices |88 and |8| both uncovered but the apparatus should be adjusted so that both of these orifices shall be covered at the commencement of grinding, and when it is desired to change the feed the orifice |88 is uncovered by the shutter arm 18, and when the work piece comes to the final size the shutter arm 1| uncovers the orifice |8|. It should be understood that by the phrase uncover I intend to indicate effective illumination of the photoelectric cells, for it is illumination by a given amount which causes their action Y andere and it is their property of acting at a critical illuminaticn which permits me to use them for accurate sizing of Work pieces and although I prefer to make the beams 92 and di very narrow neverthless I can achieve accurate sizing of worlr pieces although such beams of light may have,

relatively speaking, substantiel thickness.

In the preferred embodiment of the invention actuation yof the photoelectric cell itt causes cross feed movement between grinding wheel it and worle piece to cease, while actuation oi' the photo-electric cell |04 causes the cross feed slide I2 to retreat carrying the grinding wheel iii dednitely away from the worin` piece. Grinding be-a tween the i'lrst indication or electrical actuation and the final coming to size taires place owing to the pressures set up in the machine ports d such grinding, already lmown in connection with manually operated machines, has been termed sparlring out. The invention is shown ernbodied lin an external cylindrical grinding rnachine, but may be embodied in other `types of grinding machines, and the :first actuation in some cases may be a slowingdown of the cross feed rather than an actual discontinuance of all movement. rllhe mechanism of the present invention may he adjusted so as to bring the cross slide i2 to a stop at the first photoelectric actuation,

-or it may be adjusted so as to decrease the rate of cross feed rather than to stop it altogether.

In the preferred embodiment of the invention I use a hydraulic cross feeding mechanism which may be readily controlled by solenolds actuated by the photoelectric cells liltand |ildl. Referring again to Fig. 1, depending from the cross slide I2 is a. bracket m5 to which is attached a piston rod having a piston lill located in the cylinder itil. A slide valve |09 has reduced diameter portions ilo, lll and lit, which are separated by full diameter portions ntting a valve bore liti. A port lit connects to the right-hand side oi' the cylinder itt while a port It connects to the lefthand` side thereof. A passage l it connects the port llt with a valve port llt, and a passage connects the portl l i5 with a valve port llt. As shown in Fig. 1, the ports liti and lit are symmetrically located in the bore lill, one being slightly to the right of the center portion thereof, and the other an equal distance to the left. The bore llt also has ports |20, iii, and itt, the former being a uid entrance port and connected to pipe |23 leading to a source of fluid under pressure, and the latter two being fluid exhaust ports, the port I2 being connected by pipe |28 toa valve |24, and the port i22 being connected by piping direct to the exhaust. The valve |24 is connected by piping |26 to the piping |25 as clearly illustrated.

The slide valve |09 may be operated manually by means of a rod having a handle |3| within convenient reach of the operator, and the slide valve |09 may be operated' in one direction by means of a solenoid |32, as integrally formed with the slide valve |09 is a rod-like portion |33 which constitutes the core of the solenoid |32.

With the slide valve in the position shown in full lines in Fig. 1, fluid under pressure is admitted from the piping |23 through the port |20 and past the reduced portion to the port ||8 and the fluid passes through passage H6 to the port l |4 which is at the right-hand end of the cylinder |08 and therefore the fluid will urge the piston |01 to the left thus to move the cross slide |2 and carry the grinding wheel I5 towards and to reduce the diameter of the work piece The parts are shown at the commencement of this operation in Fig. 1. Whilepressure fluid is moving the piston itl to the left, duid. is being exhausted from the left-hand side of the cylinder itt and it Flows outwardly by way of port lit,

the fluid under pressure from the pipe Mill and port ltd passes by way ci reduced diameter poi#- tion lil to port itil and by passage iill toport lib and thus into the left-handelde of the cylinder itil. This causes movement of the piston lill to the right thus carrying the grinding Wheel it away from the worlr piece, and the fluid is forced out ci the right-hand side oi the cylinder iiitl, through port itil, passage llt, through port iid, past reduced diameter portion llt to port illlli and by way ci piping llt to the sump.

it will be noted from the foregoing description that when the grinding wheel is traveling in wardly or to the left the exhaust fiuid is passing through the valve litt, but when the grinding wheel is moving outwardly or to the right the lerhanst iluid does not pass through the valve l llt. valve and may be set to stop position; thus it The valve itil is an adjustable metering controls the advance ci the grinding wheel and procures a slow feed thereof and it iscapable of being moved to a position to reduce the feed or to stop it altogether. i

Considering now the 'construction of the valve lttand referring to Fig. l, the pip-e ltd connects to a port i3d which opens into the side of a cylinder Opposite the port itt is a port lill connecting "with the pipe lit. it close hitting piston litt is located in the bore of the cylinder llt and its movement to the left is .controlled by anv adjustable stop screw lili'. Connected to the piston itil by ineans oi a rod portion litt is another piston member lili. Another rod tilt passes into a solenoid and constitutes the core thereof. rod ittiand urges the piston lili and therefore the other parts including the piston litt to the left. The rod itl is connected at litt to a brass or other non-magnetic rod ltd which is in position to be engaged by a stop screw itl.

By properly setting the stop screw |39 as by means of a hand wheel itt the normal condition of the valve l2|l may be determined. By

may be adjusted for such part of the cycle as` involves the energization oi the solenoid N3.

According to the preferred embodiment of the present invention the machine has three main parts to a cycle of operation. There is first the infeed of the grinding wheel when the solenoid M3 is deenergized and the valve |24 is at its adjusted open or widest open position. Then follows the grinding cycle while the solenoid |43 is energized, the piston |38 being to the right and either restricting the ow of iluid through the valve |24 more than previously or else cutting it off altogether. Thirdly, there is the return of the grinding wheel to a retracted position `which is not controlled by the valve |24 at all.

'I'he change from the rst to the second phase of the grinding cycle is determined by one indication from the sizing apparatus and the change dit li spring itil surrounds the core but so far as the present embodiment is concerned may be effected by manual control, as

'a new work piece is to be introduced at this' point, and the introduction of such work piece will deenergize the solenoids and the operator has ample Itime to shift the rod |30.

It should be noted that either of the photoelectric cells |03 or |04 may be selected for initiating either change, as this is simply a matter of connection of two pairs of ilnal circuit wires. Furthermore, the sizing 'apparatus may be adjusted so that the change from the first phase to the second phase occurs at the end of the movement which brings the grinding wheel against the Work piece, or the change may be eiected when the work piece is nearly to size so that the final cuts will be in the nature of a fine grinding operation. I prefer to adjust the valve |24 so that no advance of the grinding wheel will take place after the solenoid |43 is energized, the further reduction of Ithe work piece being due to the strain or spring in the machine parts and the final cuts being what have been described as dying out cuts, or simply sparking out. The sparking out method of grinding has been found to be particularly eiIective for the production of true cylindrical fine finish and accurate work. The calipering mechanism of the invention may be readily adjusted so that the difference between actuations of the two photoelectric cells is within the range of the amount of size reduction effected by a dying-out cut.

Referring now to Fig. 5, the photoelectric cell |03 is associated with amplifying and relay apparatus to energize the solenoid |43, while the photoelectric cell |04 is associated with identical apparatus to energize the solenoid |32. Any amplifying and/or relay apparatus may be used, and direct or alternating current may be employed in any of the circuits, as my invention is not conilned to any particular electrical arrangement. For purposes of illustration, however, I have disclosed in Fig. 5 a set of circuits which may be employed. l

Referring now to Fig. 5, a 110 volt A. C. line |55 has connected toit conductors |56 and |51 leading to the terminals |58 and |59 of a transformer primary |60. Similarly conductors |56a and |51a connect to terminals |58a and |59a of a transformer primary |60a. Three secondary coils |6|, |62, and |63 are energized by the primary coil |60 and similarly secondary coils |6|a, |62a and |63a are energized by the primary coil |60a.` Non-inductive' potentiometer resistances |64 and |640l are connected across the conductors |65 and |66 and |65a and'i66a respectively of the coils |6| and |6|a. Conductor |65 leads to the anode |61 of the photoelectric cell |03 and conductor |65a leads to the anode |61a of the photoelectric cell |04. Conductors |66 and |66a lead to condensers |68 and |68a which are connected by conductors |69 and |69a to conductors |10 and |10a which connect respectively to the cathodes |1| and |1|a of the photoelectric cells |03 and |04.

'I'he secondary coils |62 and |62a respectively energize illaments |13 and |13a of amplifying or triode tubes |14 and |14a. Grids |15 and I15a of the tubes |14 and |14a are connected by conductors |16 and |16a to non-inductive resistors |11 and 11a the other ends of which are connected to the conductors |10 and |10a respectively. Plates |80 and |80a in the tubes |14 and |140, respectively are connected to conductors |8| and |8'Ia which conductors are connected to termiand |86a. Conductors |86 and |86a connect re-` spectively to the movable elements |81 and |81a of potentiometers |64 and |64a and conductors |86 and |86a are also connected by leads |88 and |8Ia to the mid points of coils |62 and |62a. It will now be seen that a certain degree of illumination of photoelectric cell |03 causes energization of relay coil |85, While a certain degree of illumination of photoelectric cell |04 causes energization of relay coil |85a. The apparatus is adjustable by means of the potentiometers |81- |64 and |81a-I64a.

In so much as the energization of the relays |85 and |85a may be momentary I further have provided a relay to close and keep closed the ilnal circuits upon any energization whatsoever of the sensitive relays. |56 also connects to a terminal |90 and conductor |56a connects to a terminal |90a. Conductor |51 connects to a relay coil |9| and conductor |51c1r connects to a relay coil |9Ia. The other ends of the relay coils |9| and |9|a are connected to terminals |92 and |92a respectively.4

Pendulum contactors |93 and |93a are adapted to connect terminals |90|92 on the one hand and |90a|92a on the other hand. These pendulum contactors are arranged to be operated by long arms |94 and |94a of armatures |95 and |95a actuated by the coils |85 and |85a.

As shown in Fig. 5, conductor Energization of the relay coils |9| and |9|a respectively, even momentary energization thereof, causes the closing of knife switches |91 and |91a. These are double knife switches and one set-of terminals thereof is connected by shunt leads to the 110 volt A. C. Wires |56, |51, and |56a, |51a respectively, While the other terminals of these knife switches |91 and |91a connect to lines 200 and 200a which respectively lead to the solenoids |43 and |32.

'I'he pendulum contactors |83 and |93a may be of spring steel so that normally they lie in the position shown in Fig. 5 but a slight force will throw them into contacting position. The photoelectric cell cathodes |1| and |1|a are preferably sensitive caesium plated cathodes and a certain deiinite amount of light on either of them will cause enough current to flow in either of the relay coils |85 and |85a to close the circuit by contactor |93 or |93a. By producing narrow beams of light 82 and 93 and providing sensitive double relay apparatus one element of which is a current -measuring relay, I am enabled accurately to size the work.

In order to set up the machine, a work piece ground to the desired size by means ofhand gauges is placed in the machine centers and the calipering device is located in position and the main switches are closed. The hand wheel 62 is oversized work piece Il placed in position will bev automatically ground to size in the manner alv ready indicated. When the operator wishes to start a particular grinding operation he draws the head I3I of the rod |30 forwardly. Many other manners of adjusting the machine and many varied cycles of operation may be adopted.

The electrical apparatus may be conveniently located at any part of the machine and takes very small space. The cross feeding mechanism involves a simple valve and a cylinder and piston unit together with a control valve. Thus the In some cases in order to make the apparatus more sensitive I may `optionally add a diaphragm with very small holes therein as indicated in dotted lines in Fig. 5 by the numeral 2li.

It will thus be seen that there has been provided by this invention an apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved.` As various possible embodi'ments might be made of the mechanical fea.-y

tures of the above invention and as many changes might be` made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is "to be interpreted as illustrative, and not in a limiting sense.

I claimz- 1. In a grinding machine, a pair of photoelectric cells, means for creating a pair of light beams directed towards said photoelectricg cells, a shutter arm, a pair of shutters on said arm, the sides of the shutters being inclined to each other so that the distance between such sides in one plane varies with the position in a plane normal to the first plane,v adjustment means to vary the increment between cutting of the beams by the shutters, a pair of controls to alter the grinding operation respectively from a coarse to a flne grinding operationand from a fine grinding operation to cessation of grinding, and devices connected to be actuated by the photoelectric cells respectively to actuate said controls respectively.

2. A work calipering device for grinding machines and the like comprising a gauge device including apair of elements positioned to engage a round work piece at different points, one of said elements-being movable, a lever, a connection between the leverand the movable element to move the lever as the work piece changes in size through grinding, a pair of shutter surfaces on the lever at an angle to each other, means for creating a pair' of light beams, oriilces towards which the beams are directed, photoelectric cells -behind the orifices, the shutter surfaces being movable across the orifices, adjustment means for the orices to move them substantially parallel to the margin of one of the shutter surfaces whereby because of the angular relation of said shutter surfaces the increment between uncovering of the orifices will be altered, and instrumentalities actuated by the photoelectric cells to control a grinding operation.

ALBERT G. BELDEN.

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