WO2018136684A1

WO2018136684A1 - System and method of rounding a workpiece

Info

Publication number: WO2018136684A1
Application number: PCT/US2018/014328
Authority: WO
Inventors: Bipin LIMBASIYA
Original assignee: Todd Reed, Inc.
Priority date: 2017-01-20
Filing date: 2018-01-19
Publication date: 2018-07-26

Abstract

A method of machining a workpiece including: supporting the workpiece in a position between a pair of pots connected to a rounding machine, each of the pair of pots may include a first end, a second end opposite the first end, an outer rim surface at the first end, and inner surface at the first end that is recessed from the outer rim surface. The method may further include setting a compressive force of the pair of pots against the workpiece such that the workpiece is permitted to rotate relative to the pair of pots. The method may further include contacting the workpiece with a grit surface of a rotating diamond disk of the rounding machine such that the workpiece rotates along a plurality of axes may include the longitudinal axis and additional axes while being supported in the position between the pair of pots.

Description

SYSTEM AND METHOD OF ROUNDING A WORKPIECE

Cross-Reference to Related Applications

[0001] The present application claims the benefit under 35 U.S.C. 1 19(e) to U.S. Patent Application No. 62/448,528, entitled "SYSTEM AND METHOD OF ROUNDING A

WORKPIECE", and filed January 20, 2017, which is hereby incorporated by reference in its entirety.

Technical Field

[0002] Aspects of the present disclosure involve a system and method of rounding a workpiece and, in particular, working a diamond into a round shape.

Background

[0003] A cabochon is a gemstone that has been shaped and polished as opposed to faceted. A cabochon stone is typically worked, rounded, or smoothed into an oval or sphere.

Manufacturing a cabochon gemstone conventionally entails continually sanding or grinding the stone at various angles until the stone is generally round. Then, the stone is polished until it is smooth.

[0004] Manufacturing a cabochon diamond, as opposed to a cabochon of other softer materials/minerals, poses particular challenges since a diamond is the hardest naturally occurring mineral on Earth. The diamond tops the Mohs' Scale of Hardness with a relative hardness value of 10. Current methods of removing hard edges of a diamond include roughly rounding via a laser, roughly cutting the diamond to shape with a diamond disk, and bruting, which is the rounding of the girdle (i.e., the thin perimeter of a faceted diamond that divides the crown above from the pavilion below) of the diamond with a lathe. Conventionally, the diamond is cemented to the end of a dop stick, and the dop stick is secured to the chuck of the lathe. The lathe then turns the dop stick and diamond, and a tool diamond that is set in a bruting stick is used to contact the girdle of the spinning diamond to remove irregular points on the girdle.

[0005] All of the aforementioned methods have their limitations including manufacturing time and inadequate quality (e.g., roundness) of the finished product. Thus, there is a need in the art for systems and methods to adequately and efficiently work diamonds into round shapes. Brief Summary

[0006] Aspects of the present disclosure may involve a method of machining a workpiece. In certain instances, the method may include: supporting the workpiece in a position between a pair of pots connected to a rounding machine, each of the pair of pots may include a first end, a second end opposite the first end, an outer rim surface at the first end, and inner surface at the first end that is recessed from the outer rim surface, the workpiece positioned between the first ends of the pair of pots, the pair of pots configured to rotate about a longitudinal axis extending though the pair of pots. The method may further include setting a compressive force of the pair of pots against the workpiece such that the workpiece is permitted to rotate relative to the pair of pots. The method may further include contacting the workpiece with a grit surface of a rotating diamond disk of the rounding machine such that the workpiece rotates along a plurality of axes may include the longitudinal axis and additional axes while being supported in the position between the pair of pots.

[0007] In certain instances, the workpiece is a diamond.

[0008] In certain instances, the diamond disk is translated along an axis transverse to the longitudinal axis.

[0009] In certain instances, each of the pair of pots may include a bore defined therein.

[0010] In certain instances, the method may further include: rotating the workpiece about the longitudinal via actuation of the rounding machine.

[0011] In certain instances, each of the pair of pots may include a girdle pot.

[0012] In certain instances, the rounding machine may include a double headed girdling machine.

[0013] In certain instances, setting the compressive force of the pair of pots against the workpiece may include affixing a position of the handle of the rounding machine such that a full compressive force of the pair of pots is not exerted on the workpiece.

[0014] In certain instances, the additional axes are non-parallel to the longitudinal axis.

[0015] In certain instances, a diameter of the workpiece is larger than a distance between the outer rim surfaces of the pair of pots.

[0016] In certain instances, neither of the pair of pots are rigidly attached to the workpiece. [0017] In certain instances, the method may further include: attaching the workpiece to a dop; securing the dop to single headed girdling machine; rotating the dop; and contacting the workpiece on the dop with a tool.

Brief Description of the Drawings

[0018] Example embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting.

[0019] Figure 1A is a perspective view of a rough diamond.

[0020] Figure 1 B is a perspective view of a round or cabochon diamond.

[0021] Figure 2A is a side view of a dop supporting a rough diamond at the tip of the dop.

[0022] Figure 2B is a view of the dop and rough diamond spinning, with a user working the rough diamond with a tool having a diamond tip.

[0023] Figure 3 is a view of the rough diamond between diamond pots of a lathe or girdling machine, with a user working the rough diamond with a tool having a diamond tip.

[0024] Figure 4 is a perspective view of a rounding machine with an unattended or

uncompressed handle, showing the diamond pots contacting each other.

[0025] Figure 5 is a perspective view of the rounding machine with a fully compressed handle, showing the diamond pots separated from each other.

[0026] Figure 6 is a perspective view of the rounding machine with a partially compressed handle, showing the diamond pots slightly separated from each other and maintained in this orientation via a wire connecting the handle and the machine.

[0027] Figure 7 is a close-up side view of a diamond positioned between a pair of girdle pots and rotating along multiple axes.

[0028] Figure 8 is a close-up, cross-sectional side view of the diamond positioned between the pair of girdle pots.

[0029] Figure 9 is a view of the girdle pots with a bore on the front end and a flat back end. Detailed Description

[0030] Aspects of the present disclosure involve systems and methods of manufacturing a cabochon or round diamond. Diamonds extracted from the earth are called rough diamonds 100, as seen in FIG. 1A, which can be of various shapes and sizes. The rough diamonds resemble crystals and may include sharp, uneven surface irregularities. Utilizing the systems and methods described herein, the rough diamond 100 can be formed, worked, rounded, or machined, into a cabochon or round diamond 102, as seen in FIG. 1 B.

[0031] Initially, a rough diamond 100 may be marked and cut into a shape and size that is ready to be worked and smoothed into a more round shape. The rough diamond 100 may be

"dopped" or adhered to the end 104 of a dop or holder 106 with quick drying cement, epoxy, or other adhesive, as seen in FIG. 2A. The dop 106 and adhered rough diamond 100 may be secured to a single headed, girdle polishing machine 108, as shown in FIG. 2B. The girdle polishing machine 108 is a rotary machine that rotates or spins the attached dop 106 and diamond 100 about a longitudinal axis of the dop 106. Having the rough diamond 100 cemented to the end 104 of the dop 106 permits only one end of the dop 106 to be secured to the girdle polishing machine 108. In this way, the rough diamond 100 is free to be worked as it is not connected, for example, to an opposing portion (e.g., live center, dead center) of the girdle polishing machine 108.

[0032] As seen in FIG. 2B, a user 1 10 may use a hand tool 112, such as a bruting stick, with a diamond tip 114 to contact the girdle portion (i.e., edge furthest from the central/longitudinal axis) of the rough diamond 100 with the diamond tip 114 of the tool 1 12 to grind down the girdle portion. The user 1 10 may continue the process of working the girdle portion of the rough diamond 100 until it is somewhat round. The user 1 10 may then uncouple the dop 106 from the machine 108, and remove the diamond 100 from the dop 106 by heating the diamond 106 and the adhesive holding the diamond 100 to the dop 106. The diamond 100 may be rotated and re-glued to the dop 106. The process of working down the girdle in the re-glued orientation may continue. In certain instances, the girdle polishing machine 108 may be used for about one hour. In certain instances, the girdle polishing machine 108 may be used for more than one hour. In certain instances, the girdle polishing machine 108 may be used for less than one hour. [0033] Next, as seen in FIG. 3, the rough diamond 100 may be securely or tightly placed between a pair of diamond pots 116 of a lathe or girdling machine 118 (e.g., a double headed girdling machine). Diamond pots 1 16 are specialized tools that can be secured to the rotating spindles of the girdling machine 1 18. Diamond pots 116 are used to support opposite sides of the rough diamond 100 in a compressive fashion so the exposed portions of the rough diamond 100 may be worked/machined. The pots 116 may be made of metal. The lathe 1 18 may be rotated about a longitudinal axis that is coaxial with the pots 1 16, and the user 110 may manually contact a diamond tip 120 of a tool 122 against the spinning diamond 100. This user 110 may reorient the rough diamond 100 within the metal pots 116 and repeat the working or grinding of the diamond 100. In certain instances, the lathe 118 may be used for about one hour. In certain instances, the lathe 118 may be used for more than one hour. In certain instances, the lathe 118 may be used for less than one hour.

[0034] Next, as seen in FIGS. 4-9, the rough diamond 100 may be worked into the final, fully- round shape of the cabochon diamond 102 using a girdle rounding machine 124 (i.e., typically used for rounding only the girdle portion of an engagement diamond) having a pair of diamond pots 126 that hold the rough diamond 100 in position. Generally, the rounding machine 124 includes a headstock containing high-precision spinning bearings, and rotating within the bearings is a spindle that rotates via a motor along an axis of rotation. The spindle may be coupled to one of the diamond pots 126. Opposite the headstock is a tailstock that may also couple to one of the diamond pots 126. Together, the pair of diamond pots 126 may rotate about a longitudinal or rotation axis extending through the pots 126.

[0035] The rounding machine 124 of FIGS. 4-9 also includes a diamond disk 128 (with a fine grade polisher 142) that rotates along a rotation axis and also translates back and forth along a translation axis transverse (e.g., perpendicular, right angle) to a longitudinal axis of the rounding machine 124. Rotation of the diamond disk 128 is also transverse to rotation of the pots 126 and diamond 100 along the rotation axis. The rounding machine 124 of FIGS. 4-9 is different than a traditional metalworking lathe in that the main tooling function of the lathe 124 shown herein is the translation and rotation of the diamond disk 128, whereas a traditional lathe is operable with a wide variety of tools and tooling to accomplish a wide variety of machining tasks (e.g., cutting threads).

[0036] In certain instances, the diamond pots 126 used with the rounding machine 124 are shown in FIG. 9, with the pot 126 on the left showing the back end 130, which is flat, and the pot 126 on the right showing the front end 132, which includes a bore 134 extending longitudinally at least partially therethrough. Examples of metal pots with a bore 134 or a cylindrical or spherical recess extending longitudinally inward is a girdle pot 134. As described herein, the girdle pots 126 are oriented in the machine 124 with the bores 134 of the front ends 132 facing inward or towards each other. The rough diamond 100 is positioned within or partially within the bores 134 at the front ends 132 of the diamond pots 126. And, the diamond pots are lightly or gently compressed together such that the diamond 100 is permitted to rotate or tumble along multiple axes (XX, YY, ZZ being illustrative and not meant to be limiting) while being held in place with the diamond pots 126, as seen in FIG. 7.

[0037] Rounding machines 124 conventionally do not utilize pots 126 with bores 134 facing inward on both diamond pots 126. Conventionally, a flat sided pot (e.g., a press pot) is used for abutting against a flat facet top of a diamond, which is above the crown and girdle (in a traditional engagement ring cut). A top pot may be used to secure the opposite end of the diamond in a conventional use of a rounding machine 124. The rounding machine 124 of FIGS. 4-6 is conventionally used to form the round girdle of the diamond, which is typically the only round portion of many traditional diamond cuts. That is, these machines are not typically used for manufacturing a fully round or cabochon stone or diamond. The method described herein utilizes two girdle pots 126 in a rounding machine 124 to round a diamond or other gemstone.

[0038] As seen in FIG. 4, the rounding machine 124 includes a biased handle 136 that exerts a closing force between the two diamond pots, which are girdle pots 126, (i.e., forcing the ends 132 together to clamp the diamond) when the handle 136 is left unattended, as seen in FIG. 4. That is, the handle 136 is configured to exert a consistent, compressive force against a workpiece positioned between the pots 126 regardless of the size of the workpiece. When a user exerts a downward force on the handle 136 to oppose the biasing, as seen in FIG. 5, the ends 132 of the girdle pots 126 move away from each other so a diamond 100 (not shown in FIG. 5) can be placed therebetween. In conventional girdling operations (i.e., only rounding the girdle of the diamond), the user 110 lets go of the handle 136 and the biasing force of the handle 136 closes on the diamond 100 with sufficient force so as to hold the diamond from rotating within the grasp of the pots 126. That is, in traditional girdle operations, the diamond or gemstone is fixed in its rotation relative to the diamond pots. In fact, traditional top pots grasp the diamond tightly, and the opposite pot compresses against the culet (i.e., small flat facet at the bottom of a faceted gemstone). When the machine 124 is activated, the pots 126 and attached diamond 100 rotate along a longitudinal axis of the pots 126, and the disk 128 rotates and translates which causes the polished wheel 142 of the disk 128 to contact and smoothen the girdle of the diamond 100.

[0039] Unlike the conventional girdling operations, the method of rounding a workpiece described herein may include using two girdle pots 126 in the rounding machine 124 and limiting a closing or compressive force of the biased handle 136 (and, thus, a compressive force of the pots 126) such that the diamond 100 is able to rotate within the confines of the bores 134 of the pots 126, but is still supported sufficiently to not fall from the pots 126. Stated differently, the method may include securing a diamond 100 in between the pair of girdle pots 126 with sufficient spacing between the pair of girdle pots 126 so as to permit the diamond 100 to tumble or rotate on multiple axes (more axes than just the longitudinal axis to which the pots rotates) while not falling out from between the pair of girdle pots 126. Stated yet another way, a distance between the pair of girdle pots 126 may be set to a fixed distance apart that permits the diamond 100 to tumble within the confines of the girdle pots 126 on multiple axes, while the distance is close enough to ensure the diamond 100 does not fall out from between the girdle pots 126.

[0040] To facilitate the tumbling or rolling of the diamond along multiple axes, the handle 136 may, for example, be secured to a housing 138 of the machine 124 via a wire 140, as seen in FIG. 6, so the full biasing or closing force of the girdle pots 126 is not exerted on the diamond 100. In certain instances, the wire 140 may be a flexible cord (i.e., capable of working in tension, but collapsing in compression) so as to restrict closing of the handle 136 (cord in tension) while permitting the handle 136 to open the girdle pots 126 (cord collapsing in compression), which increases the spacing between the girdle pots 126 and allows the diamond 100 to further tumble within the confines of the girdle pots 126. That is, with a flexible cord 140, the girdle pots 126 may slightly separate from each other in operation as the diamond 100 tumbles from within the confines of the girdle pots 126 because the flexible cord may not provide any resistance from the handle 136 being moved in a direction that opens the girdle pots 126. The diamond 100 may cause the distance between the pair of girdle pots 126 to momentarily increase (causing the cord to go in compression) and then reflexively decrease (back to the cord being in tension) because of the irregularities in the shape of the diamond 100. As it tumbles, rotates, or rolls within the confines of the girdle pots 126, the irregularities on the surface of the diamond 100 may "kick" against the girdle pots 126 and momentarily force the girdle pots 126 outward. In certain instances, permitting the girdle pots 126 to open and close a certain amount may permit the irregularities of the diamond 100 to be exposed outside the bores 134 of the girdle pots 126 such that it can be worked by the rotating disk 128.

[0041] In certain instances, the handle 136 may be locked in position with a rigid wire 140. In such a case, the girdle pots 126 may be locked in position so as to not permit increasing the distance between the girdle pots 126 as the diamond 100 rotates between the girdle pots 126.

[0042] In certain instances, the handle 136 may be mechanically or electrically locked in position, as opposed to secured in position with a wire 140. In certain instances, the handle 136 may be secured in position at the point where the girdle pots 126 initially contact the diamond 100 positioned therebetween.

[0043] Once the diamond 100 is set between the pots 126, the machine 124 rotates the pots 126 and diamond 100 about the longitudinal axis, and rotates and translates the diamond disk 128 so the fine grit polish 142 of the diamond disk 128 contacts the diamond 100 positioned between the pots 126 and causes the diamond 100 to rotate along a plurality of axes XX, YY, ZZ, for example. After a sufficient amount of time, the diamond 100 is worked into a cabochon diamond 102.

[0044] FIG. 7 illustrates a close-up side view of the diamond 100 positioned between the pair of girdle pots 126. As seen in the figure, the girdle pots 126 are spaced-apart from each other far enough such that the diamond 100 may rotate along axes XX, YY, and ZZ, among others when the machine 124 operates by rotating the girdle pots 126, and rotating/translating the disk 128. Permitting the diamond 100 to rotate along multiple axes allows all surfaces of the rough diamond 100 to rotate into the space between the girdle pots 126 where the disk 128 can then contact the diamond 100 surface.

[0045] FIG. 8 illustrates a close-up, cross-sectional, side view of the rough diamond 100 positioned between the pair of girdle pots 126. The girdle pots 126 include an outer rim surface 144, and a bore 134 defining an inner surface that is inward and recessed from the outer rim surface 144. In certain instances, the girdle pot 126 may include a spherical indentation within the outer rim surface 144. As seen in the figure, a diameter D1 of the diamond 100 is larger than a distance D2 between the outer rim surfaces 144, which are the closest surfaces between the two girdle pots 126. That is, the diamond 100 extends into the bores 134 of the girdle pots 126, and is prevented from being dislodged from the girdle pots 126 because the distance D2 between the inner surfaces 144 of the girdle pots 126 is less than the diameter D1 of the diamond 100. Thus, the diamond 100 is permitted to rotate along multiple axes, and the diamond 100 will not fall out from within the confines of the bores 134 of the girdle pots 126. In certain instances, the girdle pots 126 of the rounding machine 124 of FIGS. 4-6 may be set or locked in place where a distance D2 between the inner surfaces of the bored girdle pots 126 is less than a diameter D2 of the rough diamond 100. In this particular position, the diamond 100 may rotate along multiple axes in response to the rotation of the girdle pots 126 and contact with the rotating/translating disk 128. And the diamond 100 will not fall from the girdle pots 126.

[0046] In certain instances and uses of a machine without a constant pressure handle system (e.g., a traditional lathe with a cross-slide rotating wheel) the distance between the girdle pots 126 may also be set to a certain distance apart such that the diamond 100 is able to rotate along multiple axes or tumble while still being held in place via the girdle pots 126. That is, the methods described herein are applicable to lathes and rounding machines 124 alike with slight modifications to the mechanisms that control the girdle pots 126.

[0047] Although various representative embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the inventive subject matter set forth in the specification. All directional references (e.g., top, bottom, front, back) are only used for identification purposes to aid the reader's understanding of the embodiments of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the embodiments unless specifically set forth in the claims. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

[0048] In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without necessarily departing from the spirit and scope of the present disclosure. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the disclosure as defined in the appended claims.

Claims

Claims What is claimed is:

1. A method of machining a workpiece, the method comprising:

supporting the workpiece in a position between a pair of pots connected to a rounding machine, each of the pair of pots comprising a first end, a second end opposite the first end, an outer rim surface at the first end, and inner surface at the first end that is recessed from the outer rim surface, the workpiece positioned between the first ends of the pair of pots, the pair of pots configured to rotate about a longitudinal axis extending though the pair of pots;

setting a compressive force of the pair of pots against the workpiece such that the workpiece is permitted to rotate relative to the pair of pots; and

contacting the workpiece with a grit surface of a rotating diamond disk of the rounding machine such that the workpiece rotates along a plurality of axes comprising the longitudinal axis and additional axes while being supported in the position between the pair of pots.

2. The method of claim 1 , wherein the workpiece is a diamond.

3. The method of claim 1 , wherein the diamond disk is translated along an axis transverse to the longitudinal axis.

4. The method of claim 1 , wherein each of the pair of pots comprises a bore defined therein.

5. The method of claim 1 , further comprising: rotating the workpiece about the longitudinal via actuation of the rounding machine.

6. The method of claim 1 , wherein each of the pair of pots comprises a girdle pot.

7. The method of claim 1 , wherein the rounding machine comprises a double headed girdling machine.

8. The method of claim 1 , wherein setting the compressive force of the pair of pots against the workpiece comprises affixing a position of the handle of the rounding machine such that a full compressive force of the pair of pots is not exerted on the workpiece.

9. The method of claim 1 , wherein the additional axes are non-parallel to the longitudinal axis.

10. The method of claim 1 , wherein a diameter of the workpiece is larger than a distance between the outer rim surfaces of the pair of pots.

11. The method of claim 1 , wherein neither of the pair of pots are rigidly attached to the workpiece.

12. The method of claim 1 , further comprising: attaching the workpiece to a dop; securing the dop to single headed girdling machine; rotating the dop; and contacting the workpiece on the dop with a tool.