US1039186A - Process of regrinding and polishing perforated diamonds. - Google Patents

Description

L. POPPE. P30011535 0P BBGBINDING AND POLISHING PEBFORATED DIAMONDS. APPLICATION FILED um. 10, 1910.

1,039,186. Patented ep 24,

for all ductile metals from about, 2 mm;

LEoroLn rorrn, or BERLIN, GERMANY.'

rrtoonss or nusnmnms him roLIsHING rnnronarnn mmonns.

Specification of LettersPatent. Patented Ste-pawl, 1912.

Application filed September 10, 1910.. Serial No. 581,895.

To all whom may'concerni .Be it,known that I, LEOIOLD Form, a

subject f the King of Saxony, and residing.

at Berlin, 'Germany,have inventedcertain new and useful Improvements in Processes of Regrinding and Polishing Perforated D1amonds,of'which the following is a specification.

The subject-matter of my invention is a rocessfor regrinding and polishing perorated diamonds, so-called draw' stones, such as are employed in the wire industry diameter downward. It is well-known that these diamonds wear rough and untrue or irregular and that therefore the holes .fre-

-quently have to be reground and polished in order to" render them usable again. In the simplest known machines employed for this purpose a slender, pointed, steel needle vis rapidly pushed to and fro in the hole in the rotating stone, on which needle the grindingand polishing medium is applied. B placing the needle slantwise to the axis of? the stone a conical shape of the hole s'imilar --to,..that required can be obtained, but

it'is found that when grindingin this manner the correct shape of the hole is entirely destroyed because, according to the adjustment of the needle -in each instance, only one small zone of one side or the bore is ground In order to improve this result, special positing, motion relatively .to the axis of the hole was imparted to the grinding needle more or less complicated mechanism; but this also did not lead to the end in view, to maintain" the original conicity of the bore when polishin'g;'this was due to the guidance and rotation of the polishing-needle holder being bound to one definite fixed point' outside the bore in the stone, and the lateral motion being positive, 6. 9. derived from a cam. The shape of the holes is, however, generally always different; sometimes the 'boreis long, sometimes it is short, and the position of the bore is itself also very different in consequence of unequal sizes of the, mounts of the stones.

In addition, the needle can frequently not swing sutiiciently'out of its middle pbsition,

because otherwiselwhen reciprocating in the bore it bends or jams or forces away the stone which is only'cemented onto the tableor disk by means of wax., In consequence of these defects polishing machines of this the desired result. "Further, it has been attempted co'nically to regrind the holes in the etones by'utilizing, instead of the polishingneedles mown heretofore, a wire which is pulled taut'through the bore and is reciprocated during the grinding operation in the bore of the stone which is rotated and simultaneously oscillated about its vertical" axis.

that untrue or-irregular holes are reground round, which is very important, and conse quently an irregular hole would be ground round with dilficulty though it might be ground larger. Lastly, the consumption of expensive diamond-dust is incoinparably greater for a definite output when fresh grinding-wires are constantly'emp'loyed as compared with when only'one and the same needle point does the grim ling.

land have infact, so far as I, am aware,- nowhere been? used permanently and with.

Now a primary object of my invention is to provide an improved polishing process in which all these defects and the drawbacks fore are not present.

My improved process substantially consists in locating the grinding tool-the approved slender and conical pointed steel needlewith' its point in the hole in the stone until it rests freely withits own weight'on 'thewalls thercof,-in rotating the diamond as usually in other grinding proc-" esses, around a' vertical axis, in oscillating .guidance,i.iiamely always so 'which are entirely the needle in a manner linown'gocr 3e slowlyand uniformly around its perpendicular position or around'the axis of rotation of the stone to a delihite slanting position toward both sides or only toward one side, and according to my invention, in simultaneously gradually withdrawing the needle, while it moving toward the extreme slanting positions, from the hole he thing at a determinable slanting position; when the needle oscillates back it slides again into the hole solely under the action of ,its own weight,.without the employment of .positive far that, when the needle rests passing its middle position, freely and uninipededly on thewall of the hole in the stone. In this manner It obtain that, in the vertical po ion of the needle, its point-which moreover ca1i-be'.ground exactly. corresponding to the shape oi. the hole at the beginning of the operation contacts with the bore or hole at its narrowparts in so far as it is untrue or irregular, which is an absolute necessity in order to make irregular holcsround again.

Owing 'to the oscillation of the needle and the simultaneous withdrawal otflthe needle point from the hole 1 obtain the advantage, apart from a slanting position of the needle corresponding to the conicity of the hole, that the needle point is not bent so sharply that it loosehs or breaks oil the rotating stone, which is only secured by means of wax, but nevertheless bends at the inlet side in the cone so that the cone is made somewhat curved. v

The novelty ahdessential features of my process are, particularly, that the grindingneedle rests, in all the phases of the grinding operation, with its weight on the walls of the hole in the stone so long as it is not removed therefrom, so that even untrue or irregular holes must he ground round, and that simultaneously, when the needle passes along the wall of the hole, 5. 6, when the needle rises and falls, the polishing medium is constantly supplied to the part bein ground, which enables the most economica use of the expensive diamonddust; the correct shape of the hole gradually tapering with slightly curved walls on the one side, and optional, small enlargement of the outlet at the other sideis obtained without special adjustment of the apparatus solely by the peculiar behavior of: die polishing needle. in the hole, so that the, stones worked in this manner distinguished par-tics larly by great durability and soft and smooth drawing. lily new process has, however, other additional small "advantages lacking in processeslmown heretofore. llan ely, owing {to the free guidance otthe needle its wear is diminished; one needle diamond j .is secured in a rotatable can put into and r ea-lee out of operation in a hole without StOPPlDg the machine and disturbing the operation of other needles.

. In order that my invention may be clearly understoodreference will be made to the accompanying drawing, wherein Figures 1, 2 and '3 illustratethe operation of the tool in the diamond and the final shape of the bore 01; hole on, a scale about twenty times'the natural size.

Referring to Figs. 1 and '2, the perforated late h namely by means of a. lead plug 'r. T eplate.

funnel-shaped cavity 9.

h has a conical or The point of the needle 1:. is inserted mto the hole of a diamond, a WGll-kIlOWll polishing medium, in'general a mixture of diainond dust and oil, being previously applied to the point of the needle. VVhileithe diamood is rapidly rotating the top part of the needle oscillates and its slanting position corresponds to the desired conicity hole in the diamond. in its extreme slanting position it is raised in the hole in the diamond and, when rocking back into the perpendicular position, is released. again for falling unimpededly, so that it constantly rests on the wall of the of the When the needle is hole, grinds the hole round in the vertical I position and always provides fordistributing the polishing medium. As will be readily understood, the tool, z, e. the needle n, is not guided positively until it is being withdrawn from the hole, so that even when the diamond is not secured exactly centrically the desired action nevertheless takes place and it is impossible for the mount h of thestone to be forced off the table bear- 7 ing the plate h. v

When it is desired that the needle 11. shall oscillate only toward one side, say the angle a: as indicated in Fig. 2 the needle is raised from a certain moment onward and lies loosely on the walls of the hole so that the three Zones 5 j 3' (Fig. of the hole are worked correspondingly to the purpose in view. ,Owing to the needle. lying loosely against, and to its being drawn over, the walls oi": the hole not. only is the desired, slightly curved form of the wall obtained, hut lso cracks andsharp edges are avoided and removed. Such" an action was impossible with the-pr ocesses known heretofore because the working part was guided posioegi. are principally ground round.

lclaini: ii process for grinding jewels'having through bores, whichconsists in rotating the jewe in projecting a needle into and through the bore, in oscillating the needle from an outward position toward said axis,-

awayfrom and into coincident relation with the axis of-said bore,'. a, slightly lifting the 'needle during that periodvof lts swing or oscillating movement away from such axis,

r andin disposing the-weight of the needle .on the wallsjbf the bore during its swing substantially as described.

LEOPOLD POP PE.

Witnesses HENRY HAsPER, WOLDEMAB HAUPT.

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