US1541003A - Lapping machine - Google Patents

Description

J. W. SMITH LAPPING MACHINE Jgne 9, 1925.

Original Filed Dec. 4, 1920 2 Sheets-Sheet l @N NIQN w Lw om .wrm S E .Tl Q N -Hmm June 9, `1925. A

J. W. SMITH "-LAPPLNG MACHINE Y original Filed Dec. 4. 1920 -2 sheets-sheet 2 A vwemtoz Patented June 9,5 1925.

eeil'lwiElN-TzoFs-ice-g Jenn` W. Smm; or nnwrnrranv, CONNECTICUT, Assienonrro THE-ranura nnen,

:NG commma- QF NEW Bamm; Sommers@ wareserxolier @Madri- CUT.

. LAPHNG Application-filed. December 4,13` 20, 1Slera1 Ne.:4&,v2p2,2.p Renewed Novemberii, `1924,

To all 'Lu/wm t may concern;-

Be itfknoivn that I, JOHN lV. SMITH, a citiaen of the United States of America, residing at New BrtainfHaI'tffOrd County, Connecticut, have invented a new and useful Lappin g Machine,V of fvvhich, the' following is a specification. i y

Wy invention` relates to. i machine for grinding or lapping,"` and is particularly `adapted for grinding or lapping parallel surfaces on' articles, but .isf ,not limited to use onk articles` requiring parallel surfaces.

It `is an object of Iny invention to provide ainachine for lapping or grinding Asurfaces 5i which will perform its function andproduce alinished product` of a high Ldegree, of accuracy and uniformity.l ln general, the vobject is to iinproveand simplify theconstruction of grinding or lapping machines.

Other. objects and advantages WillV appear as the specification proceeds.

In the preferred forin of my, linvention there .isk provided apair of lapping discs mounted upon any suitable typeof frame.

A Work carrier is -interpos ed between the discs. The carrier is provided witlirneans i-orfholding a plurality of articles to be lapped. rA ineans is provided Lwimparjt to the .carrier a ,unique inovelnent relatively ,to said discs whereby the articles in the carrier will be `lapped dow-n to uniform dimensions.

1n the-drawings, which show a preferred form of machine. for-the purpose ofillustrw tion only- Figure l `is a central vertical sectionaly vienY of a machineembodying rfemtinesof` my invention; and

Fig. yE2 is a 4section taken.substantially in` the plane of the lineuQj-Q of Fig. l.

In said I,diaivingn `5 represents any suitable design of frame for si-ipportingfthe.partsof niy machine. The upperl par-t,Gviofltliefraine supports one of the lappin` discs 7; Mounted opppsite i spaced therefrom is acoinp-lenientary grind,-

ing or lapping dise 8.k For the purposeof separating" these discs fliave shown nieanS..

S, for raising-,the latter and.separatinggthe The discs 7 all@ 8 frame. `In orderto prevent ,the disc ,Sfronn` rotating I haveshovvn Yanfapertured bar 10,

adaptedto fitoverprojeetingpins 1l on .the

01' slimline, le disc 7'` and;

hier y betyveen v`tlf'ie articles and theupper .shr-

y,than the 'discs In `order-to space thefcarrier frein the discsl'ha-ve shown lipsor flanges 11i, turned down,adjacentl the 'apertures, and thesek flanges .serve to space the inain 'body Qfsaidcarrier away from -the ,lower disc' `to'better holdthe articles :tobe

lapped.A Y

Extending through one of `the, annular on. "ThisA crank 16 passes' through or `is otherwise secured to the carrier, preferably at the center of the latter. Aeap 17 Vinay be provided above `the crank, for ypreventing beelrls- Y i When the Yapertures inthe carrier are a rasive'niaterial frein enteringthe crank much larger than the 'size of the 4'articles .to

beV ,lamped,` spacer eleinents, such as discs 18,

may 'be provided to hold-the articles away from the center of the apertures. `Ths'ivill prevent" the "articles fron vreinaining in one :position relatively to. thel carrier. These spacer elei'nents are preferablyvthinnervthan thefarticles being lappedzand, iffvery thin,

invaypbe spaced away frein one of the discs in any suitable-manner, asby ineans of fianges tothe flanges 14 on the carrier." In. order Ato "provide a `Ineans- ,for introducing an abrasive substance betvvee'nthedises `and@ to4 lapped, I have indi- `catedfaire `upper surfac'eof Ythel upper disc as `providedfvith[grooves A20, in 'which an abres i i be pour fro nuifture, such as leineryand oil, inay ed'. A seriesfofapertures21-entends in theibotto'uis of thejgrooves and-through 4dis in oiderf'toperhnit the .introduction lof'. tllie abrasiveibetiveenMt/he nlower surface of t he ,abrasive will passI dovvn and fa e4 of thezvlovverbdisc.'*The excess abrasive ,vvilflffall betiveehV one of the discsfandfthe upstandinguflange 23,011 a part of the frane. The'. abiaslr 1rvsliflrg over" .the ,inner eds@ 0f 'in a single aperture they from receiving more ineaiias of a pulleyBO. The carrier is what may rier will of course ment or a rmovement substantially radialV to will actually the annular discs will find its way into the reservoir or container 24, and the abrasive mixture from these two containers may be received through pipes 25 and 26.

Due to'the relative size and positioning ofy the carrier aiidkdiscs and of the eccentricity of the crank shaft, some or all of the articles carried by the carrier will at some time durf ing the lapping operation overlap both the outside and inside edges of the annular discs, as indicated at 27, 2S. This slight overlapping of the discs by some or all of Vthe articles to-be lapped `insures `anieven and uniform wearing downv of the lapping surfaces of said discs andprevents formation. of a shoulder or ridge thereon thus maintaining a true surface.

'The operation of the machine is as follows l The plates 7 and 8 are separated and the articles to be lapped, for example, rings 19, are introduced'into the carriers. rIhe spacer 18 if used is. placed Within theapertures in the carrier to prevent the articles from moving about too freely'or remaining at the center. lVhen a plurality of articles are placed are preferably 'loosely arranged within the same to permit an interchange or ticlesfrom a`position adjacent the spacer to a position adjacent the edge of the aperture. This interchange Vwill prevent some articles than others. ered onto the articles and an abrasivemixture, such as emery and'oil, is introduced between the discs and the surfacesuof the ar# ticles. The shaft'l is next rotated, asby be termed a floating disc or carrie-r, for the latter is not eon strained to move in a predetermined definite path. The center is, of course, constrained to move in a circle with the crank 16, butv other parts of the carrier may have very different and erratic motions. As a mattei' of facti it has been foundin practice that, upon rotation of the crank, parts of the carhave an oscillating movethe discs, without moving aroundthe center of the saine while at other times the carrier rotate relatively to the discs in one directiongor the other. Ithas also been `found thatthe articles, when loosely disposed in the apertures will shift around therein and will also tend to rotate about their own axes duiing their movement within thev apertures. The motions given to the articles being lapped, while not absolutely definite and predetermined, will, in general, be a movement in and out and around the discs relatively to the center thereof, and the individual articles will likewise turn and shiftcireumfrelitially within the apertures y eration,

the lapping d1scs,1both radially andy circuml specic shifting about of the ar-V of the abrasive action v The heavy plate is then llowo articles away from tures, said last mentioned iii the carrier.v lith themovements as indicated, each article being lapped traverses, or may traverse in the course of the lapping opsubstantiallyr the entire surface Aof ferentially, and a highly accurate uand imifornr product is produced. y

While I have shown the discs as substantially horizontally mounted I do not necessarily wish to have it understood that all claims are limited to; that arrangement. i Vhile I have shown and described the machine as a lapping machine, I wish it to be understood that either one or both of the lapping discs might be replacedr by discs having inherent abrasive qualities and that my ,invention is broad enough to include grinding as wellas lapping operations. y

` Although I have described in great detail embodiment of my invention, I wish it to and modifications` may be made therein within the scope of the appended claims.

A It will be noted thatthe so-called carrier 12.,functions as a main spacer plate for the articles to be lapped, and that the so-called .discsf I8. function as secondary spacer plates for the articles to'be lapped, and that all of said plates function conj ointly in spacing and carrying the articles over the entire lapping surfaces of both lapping discs.

I claim: v

1.1In a lapping machine, a pair of discs having spaced lapping surfaces, a work carrier between said discs, and means for effecting a relatively Voscillatory movement betveen said carrier and said discs, said cai'- i'icr being also rotatableabout its own center, and said work carrier having a pluralityof -apertures for loosely holding articles to belappc'd, with means for separating a group of the articles being operated upon, said :separating: means being thinner than the ysaid articles y 2Q In a lapping 'machine,a pair of discs having spaced lapping'surfaces, a work carrier 'between said discs, and means for effecting ak relatively oscillatory movement between said carrier and said discs, said car'- rier being also rotatable about its own centei', and said work carrier having a plural ity of a-perturesfor loosely holding articles to belapped, with means 'for holding said the centers of said aper- V means being thinner than said articles.

3.A lapping machine including in combination, two opposed laps having flat working surfaces, a work carriei' positioned between said .laps andv having openings therein for'articles to be lapped, each' of said vopenings being of a size'to hold a plurality and laps in a substantially circular path, the

be understood that various changes bodily said means leaving the work carrier tree to rotate about its own axis under the influence vot the articles, the plurality of articles in each opening in the work carrier being free to rotate 'bodily about the axes of the openings so as to execute a substantially planetary movement, and spacing means'thinner than said articles and operating to hold apart certain of said articles. Y

ll. A lapping machine including in combination, two opposed laps having flat working surfaces, a work carrier positioned between said laps and having openings therein to contain a plurality of articles to be lapped, means for elifecting an eccentric motion between said work carrier and laps, said means leaving the work carrier free to rotate about its own axis under the influence ot the articles, said openingsl `in the work carrier being smaller than the elective ex tent oit' the laps by an amount slightly less4 than the total eccentricity ot' the movement between the work carrier and laps, whereby the articles in the openings may overlap the effective working surfaces of said laps and the articles in said openings may rotate berlily about the aries ot said openings so as to execute a substantially planetary movement, and spacing means thinner than said articles and operating te hold apart certain of said articles.

5. In a lapping machine, two annular laps having flat Working surfaces, a main work carrier positioned between said laps and movable therebetween, said carrier having openings, at least one et said open` ings being oi suHicie-ut size to receive a plurality of devices to be lapped, and means for spacing said devices in a ring-lille arrangement in said opening, driving means for imparting to the devices to be lapped a revolving motion around the center of the laps, a revolving motion around the center of the carrier, and a revolving vmotion around the center of said opening, said spacing means ticles, a secondary plate to space said ar-` ticles in such apertures in the main spacer plate, and means for producing relative movement between said plates and said discs Y to effect the lapping oit said articles, said secondary plate being thinner' than the articles being lapped.

7. ln a lapping machine, two co-acting lapping dises, a plate between said discs having apertures for spacing articles to be lapped, certain of said apertures being large Aenough to receive a plurality of such articles, a secondary plate to space saidl articles in such apertures in the main spacer plate, and means for producing relative movement between said plates and discs to elliect thelapping ot said articles, said secondary plates spacing said articles incircular arrangement within said apertures in the main spacer plate, and being thinner than the articles being lapped.

JQHN lV. SMITH.

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