IL105182A - Method and machine for polishing natural diamonds - Google Patents

Description

METHOD AND MACHINE FOR POLISHING OF NATURAL DAIMONDS BACKGROUND OF THE INVENTION This invention relates to methods and equipment for treatment of natural diamonds and specifically to machines for polishing of natural diamonds. This invention may be applied as well for treatment of high-precision flat surfaces of details fabricated from metals, semiconductors and dielectrics.

STATE-OF-THE-ART LEVEL OF THE TECHNIQUE There are machines for polishing diamonds' facets, in these machines polishing process is performed on the flat surface of a rotating metal disk, the external layer of this disk is fabricated from abrasive grains, the spaces between these grains are filled with mixture of a glue with natural diamond grains and synthetic diamond grains (see "TOOLS FOR THE DIAMOND INDUSTRY, "Bettonvi 1 le" company, Antverpen, Belgium, 1991, pp.22 - 25). Polishing of natural diamonds is executed as well by rotating diamond disks. A processed diamond is installed in an holder, one end of this holder is positioned on a table and the other - on the working surface of the rotating disk. A worker presses the diamond to the working surface of the rotating disk on its different sections and performs in such the manner the. pol ishi ng process, as a result the facet of the brilliant to be fabricated is originated on this diamond. The described machine has the grave drawback: nonuniform wear of the working surface of the disk and as a result - the working surface at some zones of the disk becomes irregular, and the grains which are found in these zones grow blunt. It does not give possibility to perform polishing with high productivity and to achieve small non-flatness of the treated surface and its minimum roughness. As a result, brilliancy and play of the brilliants, which were treated by this method, are impaired. There is a more advanced machine, in which a diamond, fastened in the holder, is forced against the rotating surface of a rotary polishing disk, this diamond performs circular motion with respect to the stationary polishing disk, and the cycloidal motion - with respect to the rotary polishing disk (see: "THE BEST EQUIPMENT FOR THE DIAMOND INDUSTRY", Best Mechanical Equipment Ltd, Israel, 1991, pp.30 - 31 ) .

This process of diamonds' polishing has several drawbacks: in the process of a diamond circular motion with respect to the rotatary polishing disk, the treated diamond passes the zones of the polishing disk with different circumferential speeds, it causes nonuniforn wear of the polishing disk. As a result, it leads to growing non-flatness of the working surface of the polishing disk and creation of curvilinear zones and zones with blunted grains on this surface. It causes decrease of the process output and impairment of quality of a fabricated brilliant.

Curvature of the brilliant facets leads to impairment of its brilliancy and play; - a fact, that only one diamond is treated at a specific instant, leads to that this diamond has in practice a point contact with the surface of the polishing disk and it causes creation of grooves on the working surface of the disk, it decreases as well polishing e-F-Ficiency and impairs brilliancy and play of the brilliant; - reclamation of the initial shape of the deriorated polishing disk in order to obtain its working surface with very low non-flatness presents difficult technical problem and requires great time.

SUMMARY OF THE INVENTION The drawbacks described above may be obviated if: - to keep al l time 1 ow ' non-f1 atness of a gri ndi ng-pol ishi ng disk, it ensures very low non-flatness of the brilliant facets; - to perform dressing of the diamond grains of the working surface of the gr i ndi ng-pol ishi.ng disk at the initial stage of grinding and to ensure bluntness of these diamond grains at the polishing stage of the process, it allows to achieve high rate of removal of the material of a treated diamond at the grinding stage of the process and a low roughness of the polished diamond facet at the polishing stage of the treatment.

It ensures as well high output of the gri ndi ng-pol ishi ng process, beauty, brilliancy and- play of the processed br i 11 iant ; - to provide treatment of some groups of facets of diamonds at the same time, where the treated facets of the diamonds lies in one plane, it ensures proportional increase of the g i ndi ng-pol ishi ng process output, uniform wear of the whole working surface of the gr i ndi ng-pol ishi ng disk and absence of circular grooves on the,, working surface of the grinding- polishing disk.

Therefore, this invention includes: 1. The method of gri ndi ng-pol ishi ng treatment of natural diamonds, which are forced against the working surface of a rotary g i ndi ng-pol ishi ng disk and these diamonds perform circular motion; - in this method the treated diamonds are arranged in groups; - each above-mentioned group of the diamonds executes rotation about the axis of this group and additionally -about an axis, which is not the same, as a rule, as the rotation axis of the gri ndi ng-pol ishi ng disk; - all treated surfaces of the diamonds in the groups lie in one plane; - dressing disks of the annular shape are situated between the groups of the diamonds, these dressing disks are forced against the working surface of the gr i ndi ng-pol ishi ng disk, the dressing disks are rotating around their axes and additionaly around an axis, which is not the same, as a rule, as the axis if the gri ndi ng-pol ishi ng disk; - the diameter of the dressing disks exceeds the width of the section of the gr i ndi ng-pol ishi ng disk, which is in the contact with the dressing disks; - the groups of the diamonds and the dressing disks have the property of self-adjustment with respect to the working surface of the gr i ndi ng-pol ishi ng disk; - the dressing disk are found, as a rule, in the contact with the working surface of the gri ndi ng-pol ishi ng disk at the stage of the grinding process, it ensures dressing of the grains of the gri ndi ng-pol ishi ng disk and, there-Fore, the process o-F efficient grinding o-F a diamond, thereupon these dressing disks are removed from the working surface of the gri ndi ng-pol ishi ng disk, it ensures bluntness of the grains of the gri ndi ng-pol ishi ng disk and hence low roughness of the treated surface, that is to say - high glitter of the treated facet of the brilliant to be fabriacated; - the axes of the dresssing disks are moves in relation to the centre line of the working surface of the grinding-polishing disk, if it is required to provide constant low non-flatness of this working surface, it ensures fabrication of the diamond with high precision of its flat facet. 2. A machine for gri ndi ng-pol ishi ng of natural diamonds according to the method described above consists of: - a base; - slides - a post; - a gri ndi ng-pol ishi ng disk, rotation of this disk is executed by an electro-motor through a belt drive, the working surface of this gri ndi ng-pol ishi ng disk comprises grains of natural or synthetic diamonds, grains of an abrasive material or their combinations; - units for group diamonds' fixture, processed diamonds are installed on the rods of these units, and the processed surfaces of these diamonds lie in a common plane and they are forced against the working surface of the gr i hdi ng-pol ishi ng disk. The disk performs a complicated motion, which includes rotation around the axis of the above-mentioned units for group diamonds' fixture, and, besides, rotation around an axis, which as a rule is not in register with the rotation axis of the gr i ndi ng-pol ishi ng disk; - dressing disks, which are forced against the working surface of the. gr ndi ng-pol ishi ng disk at the initial stage of the processing, these dressing disks are removed from the working surface of the gr i ndi ng-pol i shi ng disk at the secondary (completion) stage of the processing, the dressing disks ensure dressing of the grains of the working surface of the gri ndi ng-pol ishi ng disk at the initial grinding stage of the treatment and they do not prevent bluntness of the tops of the grains of this disk at the completion (polishing) stage of the treatment; the dressing disks have the property of self-adjustment with respect to the working surface of the gr i ndi ng-pol ishi ng disk; the dressing disks execute a complicate motion like the units for group diamonds' fixture; - a separator with the housings of the units for group diamonds' fixture and the dressing disks, rotation of this separator is performed through belt drives and pulleys from an electro-motor; - mechanisms of the dressing disks' displacement with respect to the g i ndi ng-pol ishi ng disk; - a mechanism for manual hoisting of the separator; - a mechanism for pneumatic hoisting of the separator; - a mechanism for turninig of the post.

BRIEF DESCRIPTION OF THE DRAWINGS The features of the proposed machine operation are disclosed in the following drawings: Fig.l - schematic demonstration of the method of natural diamonds' polishing (the side view); Fig.2 - the machine for natural diamonds' polishing (the top view) ; Fig.3 - the machine for natural diamonds' polishing; Fig. - the general housing of the dressing disk and the dressi ng disk ; Fig.5 - the general housing of the unit for group diamonds' fixture and the unit for group diamonds' fixture; Fig.6 - fastening ofthe processed diamond in the arbour; Fig.7 - the unit for group diamonds' fixture (cross-section) Fig.8 - the housing of the displacement mechanism; Fig.9 - the mechanism for hoisting and lowering the tail spi ndle: Fig.10 - the binder post of the clamp of the tail spindle; Fig.11 - two positions of the post (operating and initial); Fig.12 - the unit for group diamonds' fixture for the smooth surfaces; Fig.13 - the unit for group diamonds' fixture for smooth surfaces (cross-section) ; Fig.14 - the mandrel for mechanical clamping of a half-finished brilliant for performance of grinding and polishing its lower section; Fig.15 - the mandrel for mechanical clamping a half-finished brilliant for performance of grinding and polishing its top section.

Fig.16 - the unit for group diamonds' fixture with mechanical fastening of brilliants' blanks, inteded for polishing of the -Facets of the lower sections o-f the brilliants with the limiting ring; Fig.17 - the unit for group diamonds' fixture, intended for polishing of the facets of the lower sections of the brilliants with the limiting ring fastened inside the group of diamonds subjected to polishing operation; Fig.18 - mechanism for manual displacement of the tail ' spindle - cross-section.

EXAMPLES OF THE INVENTION IMPLEMENTATION EXAMPLE 1.

The proposed method of grinding and polishing of natural diamonds aimed to fabricate brilliant from them is implemented in the machine shown in Fig.l and 2.

The processed diamonds 1 are arranged in groups 2, axes 3 of these groups are mutually connected by separators 4. These groups 2 of diamonds 1 are forced against the working surface 5 of the gr i ndi ng-po 1 i shi ng disk 6, this disk is rotating around its axis 7. Groups 2 of diamonds 1 execute rotary motion around their axes 3 and the additional rotary motion around axis 8, this axis 8 is not in register, as a rule, with the rotation axis 7 of the gr i ndi ng-pol ishi ng disk 6. In each group 2 all processed surfaces of diamonds 1 are situated in one plane. The dressing disks 9 are positioned between groups 2 of diamonds 1, these dressing disks have the annular shape and axes 10 of the dressing disks are connected by separator 4 with axes 3 of groups 2 of diamonds 1, the dressing disks are forced against the working surface 5 of the g i ndi ng-pol ishi ng disk 6; the dressing disks 9 are rotating around their axes 10 and, additionally, - around axis Θ, this axis is not in register, as a rule, with axis' o-F the rotating gri ndi ng-pol ishi ng disk 6; the diameter of the dressing disks 9 exceeds, as a rule, the width of the section of the gr i ndi ng-pol ishi ng disk 6, which is in the contact with the above-mentioned dressing disk 9; groups 2 of diamonds 1 and the dressing disks 9 are designed as self-adjusting with respect to the working surface of the gr i ndi ng-po 1 i sh i ng disk 6 owing to hinges 145; the dressing disks 9 are in the contact with the working surface 5 of the gr i ndi ng-po 1 i sh i ng disk 6, as a rule, only at the first stage of a diamond processing (the grinding stage), these dressing disks ensure the process of efficient dressing of the grains of the working surface 5, and, as a result, the process of efficient grinding of diamonds 1, thereupon the dressing disks 9 are removed from the working surface 5 of the gri ndi ng-pol ishi hg disk, it provides bluntness of the grains of the gr i ndi ng-pol i shi ng disk and hence obtaining on a processed surface low roughness, i.e. - high glitter of the processed facet of the brilliant to be fabricated.

EXAMPLE 2 The machine intended to implement the method of polishing natural diamonds, which was described above in EXAMPLE 1 of this invention*, consists of the following details: base 11 with slides 12 fastened on the base by screws 13. Post 15 is hinged on slides 12 by pin 14, this post can turn with respect to axis 16 of pin 14.

The tail spindle 17 is positioned in hole 18 of post 15 and may perform reciprocating motion with respect to this post and may turn with respect to post 15 by key 18' .

Shaft 21 is installed in the tail spindle 17 in bearings 19 and 20. Separator 22 is fastened on the lower section of shaft 21, and slots 23 are fabricated in the upper section of this shaft, slots 23 are connected with the slots of pulley 24, which is installed on post 15 in, bearings 25 and 26.

Electro-motor 29 is installed as well on post 15 through the vi ro-absor bi ng packings 27 and 28, pulley 30 is fastened on the shaft of this electro-motor. Shaft 33 is installed in post 15 by bearings 31 and 32, pulleys 34 and 35 are fastened on shaft 33. Pulleys 30, 34, 35 and 24 are connected by belts 36 and 37. The counter weight 38 is installed as well on post 15, this counter weight allows to perform turning of post 15 with respect to axis 16 of pin 14 with a minimum force.

Bearings 39, 40. and 41 on base 11 serve for installation of spindle 42, flange 43 with shoulder 44 is fastened on one end of this spindle, and chuck 45 is installed on this shoulder 44, the chuck is installed on flang 43 by screws 46. The gri ndi ng-pol ishi ng disk 48 .is fastened on chuck 45 by screw 47, the working surface of this gri ndi ng-pol ishi ng disk is perpendicular to axis 49 of spindle 42. Pulley 50 is fastened in the Lower section of spindle 42. Electro-motor 51 is installed through the vi bro-supressi ng supports 140 on base 11, pulley 52 is fastened on the axle of this electro-motor 51. Pulleys 50 and 52 are connected by belt 53.

Besides, collector 50' is installed on base 11, this collector puts up a fence around the gri ndi ng-pol ishi ng disk 4B and chuck 45.

The machine comprises units 54 for group diamonds' fixture and the dressing disks 55, which are hinged with housings 56 of units 54 and frames 57 of the dressing disks 55.

Housings 56 of units 54 for group diamonds' fixture and frames 57 of the dressing disks 55 (Fig.4 and 5) are fastened on separator 22 by screws 58, each' frame comprises the housing 59, bushing 60 is installed in bearings 61 and 62 housing 59, gear 63 is'fastened on one end of this bushing, besides, pin 64 is situated in the opening of the bushing, pin 64 is bonded with the bushing 60 by key 65.

The spherical pivot 66 is prodused in the lower section of pin 64, this spherical pivot is provided with the leading pin 67, which is placed at the average section of the spherical pivot 66, and pin 64 is provided at its central section with thread 68 and the adjusting nut 69, spring 70 is arranged between the adjusting nut 69 and bushing 60, this" spring forces units 54 for group diamonds' fixture and the dressing disks 55 against the working surface of the gri ndi ng-pol ishi ng disk 48. Pin 64 is provided in its upper part with thread 71, nut 72 is situated on this thread and is adjusting the instant of the contact termination of the dressing disks 55 and units 54 for group diamonds' fixture with the working surface of the gri ndi ng-pol ishi ng disk 48. The dressing disks 55 (Fig.2 and 4) are positioned one in opposite to the other and each dressing disk comprises: the annular disk 74, bushing 75 which is fastened on this annular disk. by screw 146.· The thrust bearing 76 with slot 77 in its central part is placed at the bottom section of bushing 75. Presence of the thrust bearing 76 ensures self-adjusting of the working surface of the dressing disk 55 on the working surface of the gr i ndi ng-pol ishi ng disk, and locators 73 obviate possibility of disconnection of the thrust bearing 76 and the spherical pivot 66 at the instant of disconnection of the dressing disk and the g i nd ng-pol ishi ng disk 48, however, they allow to execute this manually.

Each unit 54 for group diamonds' fixture (Fig.5 and 6) has property of self-adjusting with respect to the working surface of the gri ndi ng-pol ishi ng disk 48, this unit consists of: housing 78, the average section of the unit is provided with the thrust bearing 79, preferably - of the spherical shape, this thrust bearing has slot 80 at its average part, holes 81 are produced in the peripheric region of unit 54, the axes of these holes are situated at a specific angle to axis 82 of unit 54 for group diamonds' fixture, rods 83 are positioned in these holes, grip 84 and the clamping nut 85 are fastened on one end of each rod 83, and the conical gear 86 - on the other end, mandrels 141 are arranged in the holes of rods 83, these mandrels may move in the holes of rods 83 and they serve for fixture of the processed diamonds 87 (for example by a glue or mechanical means); the processed surfaces of these diamonds in each unit 54 are adjusted in one plane, the conical gear 88 is fastened in the upper section of this unit 54 for group diamonds' fixture, teeth 89 of the conical gear 88 are connected with the teeth of the conical gears of rods 83; this gear 88 can perform a fixing turning through a preset angle and it is fixing by locator 90. Axial displacement of rods 83 is limited by screws 142 and by slots 143 fabricated in rods 83, and forcing of rods 83 against housing 78 is performed by the spring-actuated clip 91 (Fig.6) with screw 92; the conical shoulders 144 are fabricated on rods 83, these shoulders serve for positioning clip 91.

Locators 73 obviates possibility of disconnection of the spherical pivot 66 with the thrust bearing 79 in the case of interruption of the contact of unit 54 for group diamonds' fixture and the g i ndi ng-pol ishi ng disk 48, however, they allow to execute this disconnection manually.

Mandrel 141 is provi ded . wi th slot 190, and pin 191 is installed in rod 83, this pin determines the position of mandrel 141 in relation to rod 83.

The proposed machine includes gear 93, which is fastened on the above-mentioned tail spindle 17 (Fig.3 and 8), the idle gears 94 are rotating about gear 93 and transmit rotation to gears 63 of bushing 60 and futher - via the spherical pivot 66 and the leading pin 67 - to unit 54 for group diamonds' fixture or to the dressing disk 55.

The machine includes the mechanism (Fig.9 and 18) of munual hoisting and descent of separator 95, this mechanism comprises the rack 96, fastened on the tail spindle 17, shaft 97 with gear 98, this shaft is installed in the opening of post 15. Pin 99 and ratchet 100 with the handle are installed on the above-mentioned shaft 97, this ratchet can turn around shaft 97 in the case, when the ratchet is not connected with pin 99, and spring 101 is placed between pin 99 and ratchet 100.

The machine comprises as well the mechanism of pneumatic hoisting and descent 102, which provides forcing of units 54 and the dressing disks 55 against the working surface of the gr i ndi ng-pol ishi ng disk 48 and interruption of the contact of the dressing disks 55 with the gri ndi ng-pol ishi ng disk 48 (when units 54 remain to be forced against the grinding-polishing disk 48) and, if it is required, hoisting units 54 and the dressing disks 55 at the same time.

Mechanism 102 comprises (Fig.9 and 18) : rack 103 which is fastened on the tail spindle 17, shaft 104 with gear 105 which is in egagement with rack 103 and is positioned in opening 106 of post 15, and, besides, rack 147, which is placed in the opening of post 15 and is in engagement with gear 105. Mechanism 102 includes as well the air-operated power cylinder 107, which is fastened on post 15, the rod of this cylinder is hinged with the above-mentioned rack 147 by pin 108; besides, there is the air-operated power cylinder 109, the diameter of this cylinder piston 110 exceeds the diameter of piston 111 of the air-operated power cylinder 107. The air-operated power cylinder 109 is installed on the air-operated power cylinder 107 is such a manner, that rod 112 of cylinder 109 is inserted into the air-operated power cylinder 107 and plays a role of a stop for piston 111 of the air-operated power cylinder 107.

The machine comprises the binder post 113 (Fig.10) with the clamping handle 114. The binder post is fabricated in post 15 and intended -For pressing on the tail spindle 17 in the process of its motion with respect to post 15.

The machine comprises as well (Fig.3) the air-operated power cylinder 115 intended for turning of post 15, this cylinder is hinged by axle 116 with base 11, and rod 117 of cylinder 115 is hinged by pin 118 with post 15. The air-operated power cylinder 115 is intended for turning of post 15 from the operating position into the initial position (Fig.3 and 11) and vise versa.

The machine includes as well stopper 119 (Fig.3) which is fastened on slides 12, and clamp 120 is installed on post 15. The machine comprises as well the displacement mechanism 121 for performance of motion of the general housings 57 of the dressing disks 55, these general housings consist of screws 58, which connect the housings with separator 22; slots 122 of the curvilinear shape are produced in separator 22, and the center of the curvature of these slots lies on axis 123 of the idle gear 94. The curvilinear projection 124 is produced on housing 59, the curvature of this projection is the same as the curvature of slots 122. This projection 124 is inserted in slot 122, and the curvilinear slots 125 are produced in the general housings 57 of the dressing disks 55 near screws 58, these slots allow to shift the general housings 57 of the dressing disks 55 along slots 122 in separator 22.

The machine comprises as well (Fig.3) the electro-panel 126 of automatical control and the pneumatic panel 127, which allow to control the half-automatical cycle of the machine operat ion.

The proposed machine for polishing natural diamonds is operating in the following manner.

Post 15 recline in position II (Fig.11), i.e. it is found in the initial position. The tail spindle 17 are elevated by mechanism 95 of the tail spindle hoisting and descent or by the air-operated power cylinder 107 in the extreme top position and is pressed by the binder post 113 through the use of the clamping handle 114. Units 54 for group diamonds' fixture and the dressing disks 55 are removed from the spherical pivots 66. The gr i ndi ng-pol ishi ng disk 48 is removed from the machine as well.

Before the onset of the machine operation the . gr i ndi ng-polishing disk 48 is positioned on chuck 45 and fastened by screws 47. .

For grinding facets on natural diamonds a disk with the diamonds' layer or a disk with diamonds' grains, bonded by a glue in the recesses between the abrasive grains, are chosen The dressing disks 55 are fastened as well on the spherical pivots 66. For performance of grinding the facets of natural diamonds both dressing disks 55 may be chosen with the diamonds' layer, or one disk can be abrasive and the second with diamonds powder.

After positioning the dressing disks 55 on the spherical pivot 66, post 15 is shifted in the operating position I. Post 15 is fixed on stop 119 by clamp 120 and the grinding-polishing disk 58 and the dressing disks 55 are set in rotation and, by the mechanism 95 of manual hoisting or descent, the dressing disks 55 are forced against the rotating g i ndi ng-pol ishi ng disk 48, when the position of separator 22 is preliminary adjusted with respect to axis 49 of the gri ndi ng-pol ishi ng disk 48. It is achieved by displacement of slides 12 in relation to base 11 with they following fixing in a certain matual position. After termination of mutual dressing of the new g i ndi ng-pol ishi ng disk and the new dressing disks 55, the tail spindle 17 is shifted in the extreme top position and post 15 - in the initial position II.

By this means the gri ndi ng-pol ishi ng disk 48 and the dressing disks 55 are prepared for prolonged functioning.

Futher in the process of grinding and polishing upper and lower sections of brilliants, the processed diamonds 87 are installed in the unit fo group diamonds' fixture, for this purpose the processed diamonds 87 are installed by a glue in mandrels 141 and mandrels 141 themselves are inserted into holes of rods 83 in such a manner, that the processed surfaces of all diamonds are set in one plane, thereupon mandrels 141 are fixing in this position in rods 83 by grip 84 and nuts 85.

Units 54 for group diamonds' fixture are installed on the spherical pivots 66. Then post 15 is shifted into the operation position (position I) and it is fixed in this position by clamp 120 on stopper 119. Then the binder post 113 is backed off and unit 54 for group diamonds' fixture and the dressing disks 55 are lowering on the gr i ndi ng-pol ishi ng disk 48 by supply of the compressed air into the cavities 129 and 131 of the air-operated power cylinders 109 and 107. The force of pressing of the dressing disks 55 and units 54 for group diamonds' fixture against the gr i ndi ng-pol ishi ng disk 48 is adjusted by nuts 69, this pressing is ensured by springs 70.

Thereupon the onset of disconnection of the dressing disks 55 from the gri ndi ng-pol ishi ng disk 48 is adjusted by nuts 72, and the onset of disconnection of units 54 for group diamonds' fixture from the gri ndi ng-pol ishi ng disk 48 - by nuts 72, which are arranged on the housing of units 54. In this position, when the dressing disks 55 and the surfaces of the diamonds installed in units 54 lie on the surface of the gr i ndi ng-pol ish i ng disk 48, the distance between the face plane of bushing 60 and nuts 72 in the general housing 57 of the dressing disks 55 must be less than the same distance between bushing 60 and nuts 72 in housings 56 of units 54 for group diamonds' fixture, it ensures at the first stage of the treatment removal the dressing disks 55 from the grinding-polishing disk 48, and futher - units 54 for group diamonds' fixture.

After termination of these adjusting operations, units 54 and the dressing disks 55 are removed from the working surface of the gri ndi ng-pol ishi ng disk 48 by supply of the compressed air into cavities 130 and 131, and post 15 is shifted in the initial position.

Thereupon the electro-panel 126 of automatical control is switched on and the semi-automatical cycle of processing is beginning. First of all post 15 is turned into the initial position I so long as this post will be stopped by stopper 119 (clamp 120 in this case is released), -for this purpose the compressed air is supplied into cavity 133 of the ai-operated power cylinder 105. Then electro-panel 126 energizes electro-motors 51 and 29, and the gri ndi ng-pol ishi ng disk 48, the dressing disks 55 and units 54 for group diamonds' fixture begins their rotations, and supply of the compressed air into cavities 131 and 129 of the air-operated power cylinders 109 and 107 is beginning. In so doing, the dressing disks 55 and the processed diamonds 87 positioned in units 54 come into contact with the working surface of the grinding-polishing disk 48 and are forced against this disk by compression of springs 70. As this takes place, the grains of the dressing disks 55 contact with the grains of the g i ndi ng-pol ishi ng disk 48, it ensures performance of efficient grinding of diamonds 87. After certain period, when the val2ue of grinding of the diamond facet is sufficient, the grinding process is terminated and the dressing disks 55 are removed from the working surface of the grinding-polishing disk 48 by supply of the compressed air into cavity 128 and at the same time with cessation of supply of the . compressed ai into cavity 129. The piston of the air-operated power cylinder 109 is moving downwards, and the piston of the air-operated power cylinder 107 is shifted by the equal magnitude.

Because the gap between nut 72 and the face plane of bushing 60 is less for the dressing disks than the same gap for units 54 for group diamonds' fixture, also the dressing disks terminate their contact with the gri ndi ng-pol ishi ng disk and at the same time the processed diamonds remain be forced against the working surface of the gri ndi ng-pol ishi ng disk 48 by springs 70 with bluntness of its grains, which were dressed at the initial stage of the treatment. It ensures low roughness of the processed facet of diamond 87 and .its high glitter. After certain period, which is sufficient in order to cancel the roughness, which was originated on the processed facet at initial stage and with achievement of required glitter,, the diamonds are removed from the working surface of the gri ndi ng-pol ishi ng disk 48 by supply the compressed air into cavity 131, it terminates the treatment of a facet on each diamond, which was installed in units 54 for group diamonds' fixture.

Then post 15 is turned into position II by supply of the compressed air into cavity 132 of the air-operated power cylinder 115. Thereupon, with descent of clip 91 by screw 92 and by turning of gear 88 in each unit 54 for group diamonds' fixture through one scale division, each processed diamond is turned through an angle, which conforms the position of the next facet. Then clip 91 is tightened with pressing on rods 83, and the treatment cycle is repeated.

After creation of the whole ring of facets, which is positioned at a specific angle, electro-panel 126 of automatical control switches off electro-motors 29 and 51, units 54 for group diamonds' fixture are removed and replaced by the next units 54 with installed diamonds, which yet were not treated. If it is necessary to treat facets at another angle, units 54 are replaced as well, however, in this case mandrels 141 with diamonds 87 are positioned at the other angle. By replacement o-F units 54 for group diamonds' fixture all facets of the upper and lower sections of the diamonds are processed, and all these operations are performed by alone machine.

EXAMPLE 3 The machine described above serves for performance of polishing the upper facet of a brilliant. The machine of this example differs from the machine described in the foregoing EXAMPLE 2 only by the design of unit 54 for group diamonds' fi xture .

This unit 134 for group diamonds', fixture (Fig.12, 13) comprises: housing 135, the ball socket 136, mandrels 137, rod 138, clip 91 with screw 92, which serves for forcing mandrel 137 against housing 135, locators 138 with springs 139 are intended to prevent disconnection of the unit for group diamonds' fixture with the spherical pivot 66 in the process of its hoisting. During installation of mandrels 137 the processed surfaces of the diamonds are arranged in one plane, subsequently these mandrels are forced against housing 135 and clip 91 is tightened, thereupon unit 134 for group diamonds' fixture is positioned on the spherical pivots 66 of the machine and the top facet of the brilliant is processed with the sequence of operations described in EXAMPLE 2. After termination of treatment of the top facets of the brilliants installed in units 134 for group diamonds' fixture, these units 134 are removed from the spherical pivots 66 and replaced by the next units 134 for group diamonds' fixture with the installed diamonds possessing the untreated top facets .

EXAMPLE 4 There is a single difference of the machine described in this EXAMPLE 4 from the machine described in EXAMPLES 2 AND 3, in EXAMPLE 4 brilliant blanks is mechanically installed in the mandrels. Because of this, it differs from the machines of EXAMPLES 2 or 3 only by the design of mandrel 141, by position of gears 88 and by presence of locknut 192 and the locking ring 193. In the process of treatment of the facets of the lower part of a brilliant and its top facet, the brilliant blank is installed (Fig.14) in the grip and is based oyer the cylindrical surface previously fabricated on the brilliant blank by bruting.

In this case mandrel 150 is hollow and provided at its one end with grip 151 with the conical thread. After installation of a brilliant blank 153 in grip 151, this grip is compressed by nut 152. Thereupon mandrel 150 is installed in the hole in one rod 83 of units 54 for group diamonds' fixture and mandrels 150 themselves are adjusted in holes of rods 83 in such a manner, that the processed surfaces are situated in one plane, thereupon these mandrels 150 are clamped in rods 83 and following polishing of. the facets of the lower part 154 is executed according to the technology described in EXAMPLES 1 and 2.

In the process of polishing of the upper facets of a brilliant the processed blank (Fig.15) is installed in mandrel 155, this processed blank 156 is based in mandrel 155 upon the tapered opening 156', which is -Fabricated in mandrel 155, and the processed blank is forced against the surface of this tapered opening 156' by lever 157, this lever may slew around the axis of pin 158 with respect to ring 158' , this ring is based upon the above-mentioned mandrel 155 with possibility to turn in relation to the axis of this mandrel 155. Support 159 is fastened on one end of lever 157, this support forces the processed brilliant blank 156 against the tapered opening 156' . The other end of the lever is provided with screw 160, this screw serves for clamping of a processed brilliant blank in the tapered opening 156' of manrdel 155. Thereupon, mandrel 155 is fixing by key 161 in rods 83 and all processed surfaces are set in one plane, then the above-mentioned mandrel 155 are fixed in rods 83 by nuts 152 and grips 151 and gri ndi ng-pol ishi ng process of the upper facets of the briliants is performed in such the manner, as it was described in EXAMPLE 2.

EXAMPLE 5 The machine for polishing of natural diamonds, which is described in this example, performs the method of polishing, which was described in EXAMPLE 1.

This machine is different from the machine described in the EXAMPLES 2, 3 and 4 by each unit for group diamonds' fixture, which was demonstrated in the above-mentioned examles, is provided with a ring, this ring determines the rate of removal of a diamond layer from brilliant blank, fastened on these units (Fig.16 and 17).

Housing 169 of such unit for group diamonds' fixture I/O is provided with thread 171, ring 172 with the thread and lock nut -173 are mounted on' this thread 171, and the face plane surface 174 of ring 172 is perpendicular to axis 175 of unit 170, the above-mentioned face plane surface 174 is fabricated from material 176 with high hardness, for example, from a hard alloy, this surface is placed higher than plane 177, the processed surfaces of the brilliant blanks 178 are positioned in plane 177 and this difference of the heights is equal to quantity A of removal of a diamond layer required for formation of a facet on the brilliant blank 178 in order to transform it into a brilliant.

A distance between plane 177 and the face plane 174 of ring 172 is adjusted by turning of ring 172 before the onset of the polishing process, thereupon the position of ring 172 is fixed by locknut 173. The unit for group diamonds' fixture is mounted on the machine and is forced against the rotating gri ndi ng-pol ishi ng . disk as it was described in EXAMPLE 2.

After removal the diamond material, which is sufficient for formation of facets on all brilliant blanks 178, mounted in unit 170, the face plane surface 174 of ring 172 contacts with the working surface of the gr i ndi ng-pol ishi ng disk 48 and removal of the diamond material from the brilliant blanks is stopping, thereupon unit 170 is removed from the working surface of the gr i ndi ng-pol ishi ng disk 48. By following successive turning of all brilliant blanks through an angle, which conforms formation a next facet, the polishing process is repeated as long as formation of whole layer of the facets on the brilliant blanks is terminated. If removal of diamond material was inadequate, ring 172 is turned and shifted by a quantity, which is equal to the quantity of the additional removal and the polishing process is repeated.

The scale graduation 179 are performed on ring 172 in order to allow precision axial displacement of this ring.

In the example described above thread 171 is fabricated on the external surface of housing 169 (Fig.16). However, this thread can be produced as well on the internal surface of housing ISO (Fig.17). In the first case the group of the processed diamonds 181 is' arranged inside ring 172, in the second case - outside (see Fig.17). Fig.17 shows one of possible versions of ring 182 application, when this ring is situated inside group 181 of the processed diamonds, namely, in unit 170 for group diamonds' fixture, which was described in EXAMPLE 5 and which is intended for polishing of the lower sections of brilliants.

The stages of treatment of a group of brilliant blanks, fastened in unit 183 for group diamonds' fixture, are the same as the stages of treatment of brilliant blanks, when they are fastened in unit 170 for group diamonds' fixture, which was described above in EXAMPLE 5.

Complicated motion of the dressing disks with respect to the gr i ndi ng-pol ishi ng disk, their possibility to perform self-adjusting and the possibility to shift the rotation centers of the the dressing disks in relation to the grinding-polishing disk ensure the low non-flatness of the working surface of the gri ndi ng-pol ishi ng disk. It provides technological possi bi 1 i ties to obtain on processed natural diamonds high-precise flat surfaces. Additionally, owing to dressing of the diamond grains at the initial stage of the treatment and interruption of this dressing at the advanced stage of the treatment ensure high rate of removal of the diamond material and the. fol lowi ng achievement of very low roughness and high glitter of a processed diamond facet.

Besides, simultaneous processing of facets of some diamonds, when their treated surfaces are positioned in one plane, ensures high productivity of the diamonds' polishing process. INDUSTRIAL APPLICATIONS The invention can be applied with high efficiency in the industry of diamonds' processing for polishing of natural diamonds in order to fabricate brilliants.

Another area of application of the proposed invention is high-precise treatment of flat surfaces of synthetic materials, for example, synthetic diamonds, mono-crystals of gallium arsenide, silicon, and high-precise surfaces of details fabricated from metals, alloys and dielectrics, and as well details produced by powder technology.

Claims (5)

1. A method of polishing of natural diamonds by farcing of said natural diamonds against the rotating surface of a gri ndi ng-pol ishi ng disk when the processed natural diamonds execute circular motion and: - the processed natural diamonds are arranged in groups; - each said group of the processed natural diamonds has except for rotafiTon around the axis of said group, additional rotation around an additional axis, which does not coincide, as a rule, with the axis of rotation of said grinding-polishing disk; - all processed surfaces of the processed natural diamonds in said groups are positioned in one plane; - dressing disks of the annular shape are situated between said groups of the processed natural diamonds, said dressing disks are forced against the working surface of said gr i ndi ng-pol ish i ng disk, said dressing disks are rotating about their axes and they have additional rotation, which does not coincide, as a rule, with the rotation axis' of said gri ndi ng-pol ishi ng disk; - the diameter of said dressing disks exceeds, as a rule, the width of the part of said gri ndi ng-pol ishi ng disk, which is in the contact with said dressing disks; - said groups of the processed natural diamonds and said dressing disks have property of self-adjusting with respect to the working surface of said g i ndi ng-pol ishi ng disk; polishing of said groups of the processed natural diamonds is executed in two stages: at the first stage (grinding -i - stage) said dressing disks contact, as a rule, with the working surface of sai d .gri ndi ng-pol ishi ng disk and they ensure in doing so dressing of the grains of said grinding-polishing disk and hence - the process of efficient grinding of the processed natural diamonds, at the second stage (polishing stage) said dressing disks are removed from the working surface of said gri ndi ng-pol ishi ng disk, it ensures bluntness of the grains of said gri ndi ng-pol ishi ng disk and hence - obtaining low roughness of the processed surfaces and high glitter of the processed facets of the natural diamonds to be converted into brilliants; - the axes of said dressing disks are shifted in radial direction with respect to the working surface of said gri ndi ng-pol ishi ng disks in the case, when it is required to ensure high constant flatness of the surface of a processed diamond.

2. A machine for polishing of natural diamonds, said machine realizes the method of natural diamonds' polishing according to Claim 1, said machine consisting of: - a base; - slides which may perform reciprocating motion with respect to said base; a spindle, the bearings of said spindle are fastened on said base and said spindle is connected with an electromotor, which is mounted on vi bro-abso bi ng supports, this connection is implemented by pulleys and a belt drive; - a gr i ndi ng-pol ishi ng disk is mounted on the flange of said spindle and the working surface of said gri ndi ng-pol ishi ng disk is perpendicular to the axis of said spindle; - dressing disks, each said dressing disk has property of self-adjusting with respect to the working surface of said g i ndi ng-pol ish ng disk, each said dressing disk comprises: a dressing ring, a bushing with a thrust bearing preferably in the form of a ball socket, said thrust bearing is provided with a slot and a stopper in its average section, which support said dressing ring when it is removed from the working surface of said gri ndi ng-pol ishi ng disk; - a post which is hinged by a pin with said slides, said post can be turned with respect to the axis of said pin; - a separator is fastened in the lower section of a shaft, bearings of said shaft are installed in 0a{ { tail spindle, said tail spindle may perform reciprocating motion in a hole of said post; said shaft and, respectively, said separator are connected kinematicly through pulleys and belt drives with an electro-motor which is installed on said post through vi bro- i nsul at i ng supports; - units for group diamonds' fixture, each said unit has property of self-adjusting with respect to the working surface of said gr i ndi ng-pol ishi ng disk, . said unit for group diamonds' fixture comprises a general housi ng which is provided with a thrust bearing in its average section, said thrust bearing of said unit has preferably the form of a ball socket, 'said thrust bearing is provided with a slot in its average section, and the peripheric parts of said units for group diamonds' fixture are provided with openings, the axes of said openings are situated at a. certain angle to the axis o-f said unit for group diamonds' fixture, rods are positioned in said openings, one end of each said rod is provided with a grip with a thread and a nut and the other end - with a conical gear, a mandrel is installed in each said grip, said mandrel can perform rec procating motion along the axis of said rod, and the processed diamonds are installed in said mandrels mechanically or by a glue, the processed surfaces of these diamonds are situated in a common plane , and a tapered gear is positioned at the upper sections of said units for group diamonds' fixture, the teeth of said tapered gear are in engagement with the teeth of the conical gears of said rods, said tapered gear can execute fixing slewing through a preset angle; said units for group diamonds' fixture are provided with clips which are pressing on said rods in the process of polishing; - each general housing of said dressing disks and said units for group diamonds' fixture comprises: a housing, bushes, which are installed in bearings in said housing, one end of each said bush is provided with a gear and a pin is positioned in a hole in each said bush, said pin is connected by a key with said bush, the lower section of each said pin is provided with a spherical support with a leading plug situated in the average section of each said pin, and the -average section of each said pin is provided with a thread and adjusting nutfj, springs are situated between said adjusting nuts and the face planes of said bushes, said springs force diamonds, installed in said unit for group diamonds' fixture, against the working surface of said -3) - g i ndi ng-pol ishi ng disk; and the. upper sections of said pins are provided with threads, nuts are positioned on said threads, said nuts control the onset of the contact interruption of said units for group diamonds' fixture and said dressing disks with the working surface of said gr i ndi ng-pol ishi ng disk; - a mechanism of displacement of said general housings of said dressing disks, said mechanism comprises: screws, which connect said general housings with said separator^, slots of a curvilinear shape are fabricated in said separator, the centers of the curvature of said slots coincide with the axes ofYidle gea , there is as well a curvilinear shoulder on each said general housing of said dressing disks, said curvilinear shoulder is positioned in the recess, and said screws are placed'. in said curvilinear slots in said general housing; - a gear is installed on said tail spindle, said idle gears are rolling around said gear and the axles of said idle gears are installed in said separator, and said idle gears transmit rotation to said gears of said pins placed in said general housings of said dressing disks and said general housings of said units for group diamonds' fixture and, futher - via a spherical linkage and said leading plug - to said dressing disks and said units for group diamonds"' fixture; - a mechanism for manual hoisting and descent of said separator with said general housings of said dressing disks and said general housings of said units for group diamonds' -3Z- •fixture fastened on said separator, said mechanism for hoisting and descent comprises: a first rack which is fastened on said tail spindle; a shaft with a gear; a pin is fastened in said shaft, and said shaft with said gear is positioned in bearings on said post; a ratchet with an handle, a spring is positioned on said shaft between said pin and said ratchet; - a mechanism for pneumatic hoisting and descent of said separator, said mechanism comprises: a second rack fastened on said tail spindle, a shaft-gear placed in a hole of said post, a third rack positioned in said post; a first air-operated power cylinder which is fastened on said post, the rod of said first air-operated power cylinder is hinged with said third rack, a second air-operated power cylinder with the diameter, which is in excess of the diameter of said first air-operated power cylinder and said second air-operated power cylinder is installed on said first air-operated power cylinder, the rod of said second air-operated power cylinder is inserted into said first air-operated power cylinder and this rod plays the role of a stopper for the piston of said first air-operated power cylinder with the smaller diameter; - a binder post is fabricatd on said. post, said binder post comprises: a clamping handle which serves for tightening said tail spindle in the process of said tail spindle displacement in the operation, intermediate or initial positions; - a counter-weight is fastened on said post; - a stopper with a clamp is installed on said slides; - a pneumatic cylinder intended -For turning o-F said post^ which is hinged with sa i d .'.fc'as£L~S and the rod of said pneumatic cylinder - an electro-panel and a pneumatic panel intended to control the semi-automatical cycle of said machine operation.

3. A machine for polishing of natural diamonds as claimed in Claim 2, wherein the processed diamonds are fastened mechanically in said mandrels and said mandrels are installed in said rods of said units for group diamonds' fixture, and in the process of polishing of the lower facets of brilliant blanks, these blanks are fastened in grips, which is fabricated on the ends of said mandrels, said mandrels are provided with slots and'"';; a tapered thread and with a nut situated on said thread, at the same time said mandrel itself is connected with said rod of said unit for group diamonds' fixture by a pin, said pin is fixing the position of the mandrel with respect to said rod; in the process of polishing of the upper sections of a diamond, the brilliant blank with the finished facets of its lower section is positioned by these finished facets into the conical hole fabricated in the end of said mandrel, which is installed in said rod of said unit for group diamonds' fixture and from aloft the brilliant blank is pressed by a support of a lever, said lever is hinged with a ring, which is based on said mandrel and has possibility to turn with respect to the axis of said mandrel, the opposite end of said lever is provided with a screw which serves for forcing of a brilliant blank against said conical hole of said mandrel. - H-

4. A machine for polishing natural diamonds as claimed in Claims 2 and 3, wherein said general housing of each said unit for group diamonds'Jfi xture is provided with a thread, a ring with another, thread and a locknut are situated on said thread of said housing, and the face plane of said ring is perpendicular to the axis of said unit for group diamonds' fixture, and said face plane of said ring is fabricated from a hard material, for example, from a hard alloy, said face plane of said ringjis positioned higher, than the plane where the treated diamonds are fastened by a quantity, which is equal to the value of removal of the diamond layer required for formation of a facet on said treated diamond, which is converted in such a way into a brilliant.

5. A method or machine for polishing natural diamonds or other details substantially as herein before described.