US2449423A - Bezel dop and grinding device - Google Patents

Description

Sept.- 14,1948. sPlRA I 2,449,423

' BEZEL nor AND GRINDING DEVICE Filed Sept. 1, 1945 2 965 75 .1. rqz.

INVENTOR Josgj' [filial S 51% llaATToRN EY l atentec'i Sept. 14, 1948 UNITED STATES ri e FFICE 13 Claims. (Cl. 51-229) This invention relates to the field of grinding or cutting facets upon gems, and more particularly to a dop for the formation of the crown or bezel facets, and to a method of forming the crown'or bezel facets.

This application is a continuation-in-part of my application Serial No. 437,056, filed March 31, 1942, entitled Method for polishing or forming facets on gems, diamonds or the like, and apparatus therefor, now Patent No. 2,393,939, issued January 29, 1946.

In my prior application aforementioned, I have described and claimed a novel workholder or dop for the formation of the crown or bezel facets whereby mechanically held stock may be axially mounted, and by indexing the gem stock in the holder, the bezel or crown facets may be formed thereon by reason of the novel process I have devised.

Briefly, in my prior application, the process involves forming a bruted stock with a generally cylindrical portion axially disposed to the table forming portion of the gem, then forming the pavilion or base facets about an axial line perpendicular to the table of said stock, thereby providing an axial line of reference determined by the pavilion or base facets and the table, whereby the bezel or crown facets may then be accurately and symmetrically formed thereon.

While I have found that with the larger gems, say twenty or less to the karat, my holder or dop for the formation of the crown or bezel facets serves adequately for its intended purpose, I have found it economically unsuitable in my endeavor to extend the procedure to gems of the smaller sizes, such as, for example, twenty or more to the karat.

I have also found inthe use of the crownor bezel dop of my aforementioned application that whether the small or large gems are employed, there are also other economic losses involved in the wear and tear in replacing the table engaging member, due to the close clearances entailed in the contact of the face of the table and its engaging member. i Q

Accordingly, my present invention is directed to animprovement of my prior invention, and has for its object the provision of a holder or dop for the formation of the crown or bezel facets, whereby the grinding of small gems is made possible more economically than heretofore attain able, with accuracy inthe formation of the crown or bezel facets, and with substantially the same accuracy in the shape and number of the facets, to secure the highest degree of brilliancy in the gem,in a manner heretofore deemed uneconomical in respect of the so-called small gems, and with unusual accuracy in the formation of the larger gems, so that the employment of unusually skilled labor is avoided. 1

It is a further object of my invention to provide a crown or. bezel facet forming assembly whereby the crown and bezel'may be quickly and economically formed, with accuracy, requiring minimum inspection and with little disturbance caused by the wear of the parts ofthe contrivance due to the abrasion on the metal parts inworking' with diamonds.

It is a further object of my invention to provide a workholder or dop for the formation of the crown .or bezel facets in which, this highly inaccessible portion of the gem may be worked accurately and facilely, without specially skilled labor, notwithstanding inaccuracies due to the normal wear and tear of metallic parts in handling material of thehardness or diamonds.

It is still further an object of my invention to provide an. improved method for grinding and polishing the bezel or crown facets accurately to secure the maximum optical properties of the gem, while avoiding the laborious use of cements in the dop by employing a mechanical means for holding the gem in position, in an indexing device.

Other objects of my invention reside in the provision of a workholder for small objects, whereby surfaces in the nature of facets, may be ground thereon symmetrically about the object, such as in forming the crown or bezel facets, without any disturbing factor due toeccentricity which might occur, especially in mounting in the workholder the so-called small gems of twenty or more to the karat, where'purchase or holding surfaces are exposed to the minimum, and axial positioning experiences considerable difficulty;

Still further objects of my invention reside'in the provision of electrically controlled means for automatically signalling; the completion, of 1 a facet-forming operation, whereby polishing operations may be economically practiced.

For? the attainment of these objects and such further objects as may appear hereinor be hereinafter pointed out,.I make reference to the accompanying drawing forming a part of this appli cation in which: I A

Figure 1 is a longitudinal sectional view ofa workholder or dop for the formation of the crown or bezel facets, and a fraginentary portion of its mounting assembly; i i 1 Figure 2 is a side elevation taken in the direction of lines- 2-2 of Figure 1; p a i Figure 3is'an end elevation taken in thedirection of lines 3-3 of Figure 1; g

Figure 3A is a longitudinal sectional viewof Figure 1', magnifiedto show the nose portion and connection to the wiring system;

Figure 4 is an enlarged perspective viewof a detail showing the contacting element in' posi-. tion; i

Figure 5 is an enlarged perspective pavilion' engaging cone.

view of the I9I to form the frustum of a pyramid, with the main or larger base adjacent the girdle and the upper base or smaller base coincident with the surface of the table forming face I 92.

By retaining the angular position or slope to leave remaining during grinding a portion adjacent the girdle I9I cylindrical and unmodified, it will be apparent that the distance d between the perimeter of the girdle G and the chord lying in the surface table, and whichforms the side of a regular polygon, is a constant.

Thus, by maintaining the rectangular gauge face I95 tangentially to the girdle I9I at its perimeter, and axially extending a pin I90 at right angles thereto, its end I91 may be utilized to measure or to gauge the distance d.

For convenience of reference, I will refer to the distance d set off by theend I91 and the gauge face 2I2 as the differential bi-apothem, which may be defined as the distance measured in the upper base of a frustum of a regular pyramid extending normally and diametrically from one side of the regular polygon there defined to the point of intersection of a plane parallel to the axis and tangential to a circle circumsc-ri'bing the regular polygon in the lower base.

It will also be observed that symmetry of the crown or bezel fawts is assured as long as the differential bi-apothem remains constant in the formation of facets upon the crown bezel, with a regular polygon adjacent the table of the gem, regardless of the possible eccentricity of the diamond stock in relation to the axis of the dop.

With this premise, I will now refer to the views wherein I provide a gauge holder 200 comprising a generally rectangular plate, one end of which is provided with fingers 20 I--29 I, inwardly turned to seat in orifices 203-203 formed in the sleeve I50. A spring clip 204 is anchored by a screw 205 at one end. The free end 206 resiliently presses down upon the holder 200, thereby permitting pivotal movement of the gauge holder I200. The free end of the gauge holder 200 is provided with a bolt 201, having a riveted head 208, which clamps the L-shaped leaf 209 to the holder 200. The L-shaped leaf 209 has a branch 2I0 which projects through an orifice 2| I formed in the extension I66. The branch 2| 0 terminates into a rectangularly shaped bearing end or gauge face I95, which is arranged to be urged by the spring clip 204 to contact the perimeter of the girdle of the stock D.

For convenience, the gauge face 2I2 will be referred to as the girdle contact and the pin end I91 will be referred to as the control contact I91.

The bolt 201 previously described is fixed to th plate 200 by the nut 2I3, and along the shank 2", the bolt is formed with a longitudinal slot 2I5.

With the construction just described, there is then provided an L-shaped fine spring steel wire 2I6, of which the shorter branch 2I1 is disposed in the slot 2I5 by first mounting a coil spring 2I8 on the shank 2I4 of the bolt, thereupon positioning a washer 2I9 and gripping the branch 2 I 1 in position by the nut 220.

The longer branch 22I extends against the face of the plate I14, which is formed with a groove 222 deeper than the wire to center the free end and provide the control contact I91 previously mentioned. The branch 22I is held in the groove 222 by the branch M0, to slide freely within the groove, notwithstanding any pressure which the face I14 may exert upon the table I92 of the stock diamond D, 1 a j It will thus be seen that a variable dimension may be secured between the free end 2I2 of the leafs 209 and the contro1 contact I91 which may be extended to bear. upon the table I93 of the stock D when guided in the groove 222. The contact I91 projects beyond the apex I12 of the plate I08 and therefore leads in its contact to the turn table or skeif 223.

The turn table or skeif .223 is usually made of cast iron upon whose face diamond dust is provided for the polishing or facetting operation. as will be understood by the worker in the art. The shaft 224 thereof carries a commutator 225, making contact with the conductor 226 leading to a make and break device 221, which actuates a signalling or like device 228, then leading through the conductor 220 connected to the set screw 205 on the sleeve I50. It will be apparent that the circuit will be completed or made when the control contact I91 comes in contact, or reaches a predetermined closed circuit making position with the skelf 223.

Having now described the installation, the operation of the mechanism is as follows: The bruted stock D with the pavilion facets I already formed thereon, is positioned upon the adapter'IGD to have the pavilion facets in contact with the facets of the flared seat I 93, formed in the adapter I60, exposing the table I93 and the cylindrical section G. The plate I68 with the branch 22I fitted within the groove 222 is then availed of to seat the stock D in position, care being taken to nest the facets I90 and those on the flared seat I53 into contacting engage ment, and to press the surface I14 against the table forming portion I92. 1

The branch 22I should be free to move in the groove 222.

Pressure is then applied by the collar I16 to grip the gem firmly in the dop. When in this position, the branch 2 I 0 is then brought into contact with the bruted girdle or cylindrical perimeter I9I. The thickness of the branch 200 is calculated to exceed the height or altitude of the cylindrical perimeter I9I and the layers forming the branch 2I0 may be laminated or built up, or diminished, in accordance with the height of this cylindrical perimeter.

With the stock D so positioned, by manipulation of the nut 220, the control contact I91 is brought into the position which it is desired to have, outlined on the table forming face I92 by the regular polygonal outline P. The dop is thereupon mounted on the block 56 and the angularity'of the dop is adjusted in respect of the turn table or skeif 223, to form the facet I94. This angular positionis one which will assure a. remnant of the circular perimeter I 9| and which, of itself, will be completely circular and which will be in constant contact with the gauge face contact I95, previously mentioned, and referred to as the girdle contact.

Upon effecting the grinding operations, the assembly gravitates or moves under pressure with the diamond in contact with the surface of the turn table or skeif 223. This operation progres-- sively 'bringsthe control contact I91 into closer position .in respect of theskeiflto complete the signal circuit when the proper depth of out has been reached. j 1 j I j I The assembly is then convenientlyraised, and then the hand wheel I83 may be indexed preparatory to cutting the-next facet; The same operation is then repeated in accordance with the number of facets outlined .by. the regular polygonantenna 7 P, without any iother adjustment f '.:thec:conti:'ol contact.

;It'will be observed'thatiin view-of the fragment of circular contour:left at .the periphery I 9 |,-the assembly automaticallyserves toiprovide a symmetrical formation .of the facets despite any eccentricity of the -stock D :on 'the dop aor ;holder, since the measurement, so to speak, is 'made:'by reference-to the perimeter l9! zand'notiby reference to theaxial lineofthe dop.

Thus, it will be seen that this :arrangement provides :means :to :predeterminedl-y measure off the distanced'on the'diiierential bi-apothem, which :is also the major fdiametric chord intersector in reference to the 'chordal positionof the facet edge terminating inthe table I93.

It will alsoibe observed :thatrby this arrangement the wear and tear "on the nose of the adapter l 60, due to the "difieren'ce inrhardness of the .diamond stock D and the materialof which theadaptor IBDis made, does not critically affect the installation.

Eccentricity due to :this type :of wear is compensated for by the controlas determined by the differential bi-apothem measurement.

The utilization of an anti-friction spring .zf'ed thrust bearing serves to press the stock D against the plate I68, with pressure permitting of the rotative indexing operation, withoutthe necessity for releasing the grip upon the stock in movin from. one indexing position to another. This is ipeculiarly valuable in connection with the measurement gauge provided by this installation.

-While;I have described that the 'wcrkholder or dop and the measurementgauge are;pecu1iare ly valuable informingthe 'crovvn facets where the diamonds run twenty or more to the karat, it is to be understood that the sameprinciple is involved-in the facetingrof larger stockmaterial, where thefaceting operation may be performed with unusual uniformity and more or'less automatically, so that assingle workman'maysupervise a number'of machines simultaneously.

It will also'be understood that While Ihave .described andset'iorth'an arrangement for securing the most desirable results by employing the complete assembly, novelty is attributed to the use of segregated parts of the installation, as more specifically-set forth in the appended claims.

Having thus described-my invention and'illustrated its use, What I claim as new and desire to secure by Letters'Patent isz 1. In a dop provided with. means =1or-rotationall-y mounting a gem with thergirdlei-portionexposed, the combination-comprising agirdle: guide movable during rotation of thegem intaccordance with any eccentric location thereof, a contactarranged to-diametrically extenrlacross said ge1'n, said contact being mounted :to move inzsynchronism with saidguide whereby tagauge the dis-,- tance for cuttin a facet on said gem.

:In a dopfor facetingthebezelof diamond stock having a pavilion :segment, a table and fa generally cylindrical segment 'p10Vidl1'lg ea :girdle, a mechanical dop having opposed seats for cengaging [said 1 pavilion and table including :a body portion in which oneaof :said seats is .ijourn'alled for indexing-anelectrical signalling system therefor, the combination of means to gauge the depth of .thefacet tolbeformed including aicontact arranged to lie on 'th'e' girdle ofthe diamonda carrier for said contact 'mounted on said body, including :means on the body for: resiliently maintaining the contact in engagement with-"said girdle, a Ffa'cet sedge limiting control fcontact coupled to said. girdle contact :extended :toward Lthe opposite'side of said girdle whereby the portion of said control :contactismade constant irrespectiveof eccentricityof 'said'diamond stock by the I indexing. means, whereby the difierential biapothem may be gauged during indexing, and electrical conductor means for connecting -=said contacts in said signal indicating system In a dop for faceting thebezel uponstock having a pavilion segment and a table forming portion outlining therebetween a: girdle forming portion, said dop including opposed-seats for saidpavilion and table, means for rotating saidpavilion engaging element includingindexing means, gauge means including a portion urged incontact with said girdle and extendingdiametrically from said girdle'adjacent a portion of the stock to have a facet formed thereon, means on said table engaging seat for guiding said gauging means slidably in relation thereto --whereby said gauging means is slid in any eccentric movement of said stock during indexing.

AVA dop for holding bruted gem stock for faceting the same'comprising a bodyportionya pavilion seat and a table engaging seat axially disposed from said body, and'means for journailing said pavilion seat whereby said stock may be indexed while held between said seats, in combination with means'for gaugingtheditferential bi-apothem including means on said body supporting a girdle contact resiliently, a control contact diametrically disposed with relation tosai'd stock and guided in said table-seat, means for adjustably positioning the girdle and control contacts in relation to 'ea'ch other whereby the predetermined depth of facet may be formedirrespective of any eccentric indexing of said stock.

5. In a diamondholderordon-a seat" against whieha diamond is held, a guide on the holder, a feed member adjustable along said guide, a contactfinger atone end of thefeed member and projecting" from saidguide, and adapted'to have its .end located ina predeterminedposition .relative to a diamond held against the seat, springmeans .engagingsaid feed'member and acting to urge the finger toward the diamond, and at least one adjusting member on the .feed member Ito determine the extent towhich theifinger. is urged by :the spring meanstoward the diamond, to indicate a point to which the diamondshall be ground.

.6. Ina-diamond holderorxdopas calledjorin claim 5, including'signalling means, :an' electric circuit "for actuating said signalling means, the diamond holder being so connected in said .circult together with the .ipolishin'g wheel against which it holds the diamond, that contact of the finger with isaid wheel will .close' the circuit, to actuate. the-signalling means.

'7. A'dop for faceting a gem havingragenerally cylindrical segment and ca pavilion segment ineluding-opposed members, one for engaging the table'forming portion of the gem, theioither .including a seat for engaging the pavilion forming portion, means for directing said members toward eachother .to'bind said gem andtto expose the girdle forming portion adjacent the bezel of said gem -and means for angularly directing said dop and holding it for "rotatably exposing said :girdle forming'portion in combination with agauging element carriedby one of the meme.

bers including a portion to contact the girdle forming portion and extending tea-point indieating the extent of the differential bi-apothem whereby said point may serve to indicate the depth of cut of the facet.

8. In a diamond or the like polishing device including a den for holding a bruted diamond stock defined by a generally cylindrical segment terminating in a table and a pavilion, said dop comprising the combination of a body portion, an axial member journ-alled therein, a seat on said member for engaging the pavilion of said diamond, an extension from said body including a plate for engaging the table of said diamond, means for supporting said dop to direct the girdle forming portion to the polishing surface, an element carried by a portion of the body contacting the girdle forming portion and having another portion extending diametrically across said gem to be polished to expose a contact portion spaced from the girdle contacting part and to contact the stock to outline the differential biapothem, and to indicate on the stock the terminal edge of a facet, signalling means, an electrical circuit for actuating said signalling means, said contact being connected in said circuit so that predetermined contact of the element wit-h the polishing wheel against which the diamond is held will actuate the signalling means.

9. In a diamond or like gem facet polishing device including the combination with the dop for forming the facets by holding the gem to expose the girdle portion adjacent a polishing surface of a lap and to form the facets adjacent the girdle comprising means to rotate-the gem to index it for the facets to be formed, including means to mount the dop and the polishing surface with respect to each other, of a gauge having a portion for contacting the girdle of the stock, and means for mounting said gauge to yieldingly urge said portion into contact with the girdle during indexing of the gem, and another portion of the gauge to contact the stock to outline the differential bi-apothem to indicate on the stock the terminal edge of a facet and the distance to feed the stock and polishing surface with respect to each other.

10. In a diamond or like gem facet polishing device including the combination with the dop for forming the facets by holding the gem to expose the girdle portion adjacent a polishing surface of a lap and to form the facets adjacent the girdle comprising means to rotate the gem to index it for the facets to be formed. including means to mount the dop and the polishing surface with respect to each other. of a gauge having a portion for contacting the girdle of the stock, and means for mounting said gauge to yield ngly urge said portion into contact with the girdle during indexing of the gem, and another portion of the gauge to contact the stock to outline the diff-erential bi-apothem to indicate on the stock the terminal edge of a facet and the distance to feed the stock and polishing surface with respect to each other, and signalling means to indicate when the gauged distance has been so fed.

11. In a dop for a bruted gem stock having a pavilion segment, a bezel forming segment and a girdle formed thereon, said dop including means for holding the gem stock upon a seat including indexing mean for rotatively applying said gem stock upon a polishing lap surface, the combination of means to gauge the stock to indicate on the stock the terminal edge of a facet in the indexing positions of the stock, said gauging means including a portion contacting the girdle of the stock and including another portion ex tending diametrically across the gem stock and toward the facet to be formed, to have an end of the latter named portion indicate on the stock the terminal edge of the facet, a signalling device, an electrical circuit for actuating said signalling device, said portion extending diametrically across said stock being connected in said circuit of said device so that contact of the said end with the polishing lap against which the gem is held will actuate the signalling means.

12. In a d-op for a bruted stock having a table forming portion, a generally cylindrica1 segment and a pavilion forming portion, stock holdin means comprising opposed seats on said dop, each having means for engaging the table and pavilion and including means for journalling said holding means for rota'tably mounting the stock, means for indexing said stock in accordance with the number of facets desired, the combination of gauging means having oppositely spaced por 'tions, one portion of which has a contacting area which ride on the said cylindrical segment, the other portion of which extends diarnetricalll across the stock to outline on the stock the limits of the side of a facet coincident with the differential bi-apothem which is positioned to contact grinding lap when a facet is completed, signalling means, and a connection between said signalling means and gauging means for indicating said contact.

13. In a diamond holder or dop for facetlng gems including means for holding the gem against a polishing surface and axially adjustable on said dop for indexing, and with the girdle exposed to facet the gem circumferentially adjacent the girdle and to one side thereof, the combination comprising a gauge having a portion for contacting the girdle of the gem stock and means for mounting said gauge, yieldingly to urge said portion into contact with the girdle of the gem during the indexing of the dop and another portion of the auge to contact the stock to outline on the stock the terminal edge .of a facet and the distance to feed the stock and polishing surface with respect to each other, and signalling means to indicate when the gauged distance has been so fed.

JOSEF HILLEL SPIRA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 615,083 Lyon Nov. 29, 1898 709,229 Many Sept. 16, 1902 740,902 Oostendorp Oct. 6, 1903 750,449 Gillard Jan. 26, 1904 802,368 Coleman Oct. 24, 1905 1,033,749 Strong July 23, 1912 1,166,843 Loesser Jan. 4, 1916 1,168,853 Coleman Jan. '18, 1916 1,173,173 Coleman Feb. 29, 1916 1,191,746 Thomson July 18, 1916 1,305,038 De Vries et val May 27, 1919 2,276,789 Nagy Mar, 17, 1942 2,320,376 Mueller June 1, 1943 FOREIGN PATENTS Number Country Date 22,853 Great Britain Dec. :31, 1891 96,877 Germany May 3, 1898

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