US2351095A - Polishing machine for v jewels - Google Patents

Description

June 13, 1944. V c BLANCII-ION 2,351,095

POLISHING MACHINE FOR "V" JEWELS Filed Jan. 11, 1943 2 Sheets-Sheet 1 22 24 v a 41 z$;fi 19 1,10 34 23 25 1 5.; f2 1 3 /J a INVENTOR. 10m CflZa/zr/wn, BY

jaww WM:

giro/ME) June13, 1944. c. BLANCHON POLISHING MACHINE FOR "V" JEWELS Filed Jan. 11, 1945 2 Sheets-Sheet 2 n 0 d mu mm mm m a w Patented June 13, 1944 POLISHING MACHINE FOR V JEWELS Louis C. Blanchon, New York, N. Y., assignor to Meyer'Koulish Co. Inc., New York, N. Y., a corporation of New York 1 Application January 11, 1943, Serial No. 471,996

' 10 Claims.

The invention relates to the art of polishing jewels and provides more particularly a machine for mechanically and automatically polishing V-shaped cavities in jewels.

The objects and advantages of this invention will appear from the description which follows accompanied by drawings showing for purely illustrative purposes a preferred embodiment of the invention. It is to be understood, however, that the description is not to be taken in a, limiting sense, the scope of the invention being defined in the appended claims.

In the drawings:

. Fig. 1 is a plan view of a preferred form of polishing machine and drive therefor, some parts being shown in section;

Fig. 2 is an elevation of the polishing machine shown in Fig. 1;

Fig. 3 is a side view of an element Of the drive, a section being taken on line 3-3 of Fig. 1;

Fig. 4 is an enlarged sectional view of a V jewel;

Fig. 5 shows a bottom polishing tool andchuck therefor;

Fig. 6 is an end view of the tool shown in Fig. 5;

Fig. 7 is an end view of the chuck shown in Fig. 5;

' Fig. 8 shows a side polishin tool and chuck therefor;

Fig. 9 is an end view of the tool shown in Fig. 8;

Fig. 10a illustrates the operation of polishing the bottom of a. V jewel; and

Fig. 10b illustrates the operation of polishing the sides of a V jewel.

In the following description and in the claims various details will be identified by specific names for convenience, but the names are intended to be as generic in their application as the art will permit.

Like reference characters denote like parts in the several figures of the drawings.

The V jewel I!) to be polished is held in a suitable mounting, such as a collet' chuck II, fitting into a tapered bore I2 of a floating work spindle I3. The spindle I3 is mounted for rotation and for axial displacement in bearings I4 and I5 of a suitable support or base I6 which may be secured to a bench by screws [1.

The spindle I3 carries a belt pulley I8 secured thereto by a pin I9. Suitable means are provided for urging the spindle I3 in an axial direction,

a helical spring being employed for this purpose in the illustrated example. The spring 20 bears against a thrust plate 2i against which the spindle I3 rests and is adjustable in tension by a knurled screw 22 in a sleeve 23. The sleeve 23 is screwed into the base at 24 and forms the bearing I5.

A tool spindle 25 is mounted for rotation in bearings 26 and 21 of a second support or cradle 28. A pulley 29 is secured to the tool spindle 25 by a. pin 3|]. The mounting of the tool spindle is preferably such that the spindle has no freedom in an axial direction, a shoulder 3| and spacers 32 and 33 being provided to locate the tool spindle 25 relatively to its bearings 26 and 21.

The relative arrangement of the work spindle I3 and the tool spindle 25 is such that the spindles are normally aligned. Means are provided for displacing one spindle parallel to its axis to produce a certain desirable movement between the polishing tool and the jewel as will be hereinafter explained in greater detail. For this purpose the cradle 28 is pivotally mounted for rocking movement on a bar 34. The bar 34 has a shoulder at 35 and an end portion 36 of reduced diameter on which the cradle 23 rests on pivot bearings 31 and 38. A collar 39 secured to the reduced portion 36 by a pin 40 holds the cradle in place. A double pulley M is mounted on the end portion 36 and drives the pulley 29 by a belt 42. The double pulley 4| is located relatively to the cradle by spacers 43 and 44. The bar 34 is adjustably held in the base I6 by hand operable screws 45 and 46 permitting of an adjustment in the distance between the work spindle and the tool spindle.

Means are provided for periodically displacing one spindle parallel to its axis during the polishing operation. That is to say, the spindle has an oscillating movement transversely of its axis in its normal position but the axis of the spindle in any displaced position is parallel to the axis of the spindle when in its normal position. In the illustrated example an eccentric 41 imparts a rocking movement to the cradle 28 through a rod 48. The rod is connected to a crank pin 49 of the eccentric with one end and is linked to the cradle with the other. The connection of the rod 48 with the cradle is conveniently made by means of a bolt 50 having a forked end 5| to which the rod 48 is linked by a pin 52. The bolt extends through the cradle 28 and carries a thumb nut 53 bearing against one end of a helical spring 54. The other end of the spring 54 rests against the cradle. The bolt and spring arrangement permits an additional parallel displacement of the tool spindle by hand to facilitate the insertion of a tool, as will hereinafter appear. It will be understood that parallel displacement as herein used means the'spindle may be displaced transversely of its normal position but when displaced the axis of the spindle is parallel to its axis when in normal position The eccentric is preferably driven jointly with the work and tool spindles to coordinate the rocking the cradle with the rotation of the spindles. In the illustrated example, the eccentric 41 is mounted on a drive shaft 55 by a pin 56a. The drive shaft rests in bearings 51 and 58, carries pulleys 59 and 60 for driving the pindles and a belt pulley 6| for connection to a prime mover or motor (not shown). A belt 62 connects the pulleys 59 and I8 for driving the work spindle l3 in one direction, and a crossed belt 63 connects the pulleys 60 and 4! for driving the tool spindle 25 in the opposite direction.

The eccentric 41 is preferably adjustable to vary the amplitude of the rocking movement of the cradle. Forthispurpose, one crank pin 49 may be mounted on a cross-head 64 adjustable in a guideway 65 by means of a screw 66 (see Fig. 3). I

A V-jewel is shown in greatly enlarged section in Figure 4. The jewel consists of a body l of sapphire, ruby or other suitable material and has a V-shaped cavity produced by drilling or grinding. The cavity comprises a curved bot tom portion '61 and a straight wall portion 68 including an angle a.

The size and the angle a of the V-cawty vary according to the purpose for which the jewel is to be used. A much used jewel has a cavity measuring one millimeter in diameter measured across the face of the jewel and an angle a of 85 degrees. s I

Although the bottom and the wall portions 61 and 68 of the V cavity may be polished in one operation by means of a single tool, it is preferred to employ separate tools for polishing the two portions, each tool being designed for its particular purpose.

The polishing tools are preferably made of resilient non-metallic material, such as fibre or wood, the latter being particularly well suited. Diamond'dust mixed with a lubricant serves as a polishing medium.

A preferred form of bottom polishing tool and chuck or holder therefor are shown in Figures 5 to.7. The tool 69 consists of a piece of material of elongated, preferably rectangular cross section, as shown in Fig. 6, and has sides which taper towards one end. A convenient length for the tool is approximately 60 millimeters. Commercially available toothpicks of the form shown, are admirably suited as polishing tools. The point H of the tool is trimmedto the approximate angle or of the cavity to be polished by means of a conventional cutting implement, such as a pair of scissors or a side cutter used by instrument makers.

The tool is held in a suitable chuck preferably in such manner as to impart a rotation to the tool while permitting the tool to tilt relatively to the chuck at the point of engagement. A suitable chuck for toothpicks is obtained by drilling an axial hole 12 into a center 13 and slotting the face of the cone I4 of the center to about one-half the depth of the hole as shown at 15 in Figures 5 and '7, the incision being at right angles to the axis of the center. The chuck thus obtained holds flat toothpicks firmly for rotation and permits of considerable tilt at the point of engagement' The chuck may be provided with a taper l6 fitting in a. corresponding bore in the tool spindle 25.

A preferred form of side polishing tool is shown in Figures 8 and 9. A round piece 11 of suitable material such as wood is securely held in a chuck 18 which may have an internal taper 19 for gripping the tool and an external taper 80 fitting into the tool spindle 25. The point 8| of the tool is accurately shaped to the angle a of the V-cavity to be polished, which is conveniently done by grinding the point on an abrasive disc. A convenient length for the polishing tool 11 is approximately 25 millimeters measured from the point H to the chuck 18. A commercially available round toothpick measuring about 2% millimeters in diameter is very well suited as a side polishing tool. Diamond dust mixed with a lubricant serves again as a polishing medium. It will be noted that in the illustrated mounting the tool 71 is relatively rigid because of its larger cross section and its shorter length as compared to the bottom polishing tool 69, a preferred free length being approximately 25 millimeters measured from the point to the chuck. The tool is held rigidly in the chuck 18, there being no freedom of tilt at the point of engagement between the tool 11 and the chuck. v

The operation of the polishing device is as follows: After insertion of a jewel [0 into the collet H the collet is placed into the taper l2 of the work spindle l3 causing the collet to close and hold the jewel firmly. A polishing tool 69 or 11 is then inserted with its chuck 16 or 18 in the tool spindle 25. For convenient insertion of the tool, the cradle 28 may be tilted by hand about its pivot 36 against the actioirof the spring 54 causing the tool spindle 25't0 be brought out of alignment with the work spindle l3. The point of the tool to which a polishing agent has been applied is then placed in the cavity of the jewel I0 which is facilitated by retracting thework spindle in its floating mounting against the action of the spring 20. l

After the drive shaft 55 is set in m0ti0n,the work and tool spindles are rotated in 'opposite direction through the belts 62, 42 and 63. In addition, the cradle 28 is rocked about its pivotal axis by the eccentric 41, the proper amount of oscillation being determined by a suitable adjustment of the crank pin 49 and cross-head 64 in the eccentric. The rocking of the cradle 26 cause a change in the distance between the jewel and tool chuck which is compensated for by the floating mounting of the work spindle l3 urged towards the tool spindle by the spring 20.

A suitable speed for polishing a jewel having a V-cavity of about one millimeter diameter, measured across the face of the jewel, is approximately 4000 R. P. M. for the work spindle l3, and 4000 R. P. M. for thetool spindle 25. The resulting total relative speed between the jewel and the tool is therefore approximately 8000 R. P. M. The eccentric is preferably so driven as to make one complete revolution for 25 revolutions of the tool spindle or revolutions of the jewel relatively to the tool. i I

The polishing-action which takes place within the cavity of the jeweland the minute movements of the points of the tools relatively to the cavity are about as follows:

The bottom grinding tool 69 is shown enlarged in Figure 10a in which the size of the jewel is exaggerated to facilitate the illustration.

As hereinbefore set forth, the point of the bottom polishing tool 69 is of nearly uniform thickness 1(Eig. 6 sand is :shaped approximately -zto .the angle a :formed by the side walls ;f the 'V-ecavity. .A polishing medium is ,appliedto the .point and the machine fis then set in motion. .As ?the tool is rotated, the .point H of the tool undergoes a certain wear under thepressure'of "the .-spring '20,;it being :apparent that the "wear is the greatest "near the opening of the cavity at :"tance between the jewel .10 and the chuck I3.

Asa result the tool is rapidly worn away at b and lb and bears primarily against the bottom 61 of the cavity withritstipr ortion C, thus polish- ;ing the same.

The relative motion between the tool and the .cavity is both rotary :and translatory. the .rotary movement being, of course, the rotation imparted to the tool by the .tool chuck 1.3, a translatory movement e being produced by the rocking of the cradle, causing the side portions b and b .of the tool to bearagainst the edge of :the

cavity and forcing the .tip 0 over to thesurface near the bottom opposite the point of contact. In the position shown in heavy lines in Figure 100. the point of .thetool contacts the edge of the cavity near 11 forcing the tip 0 below the center aline d-d. In the position'shown in broken lines the point of contact is near b forcing the tip 0 above -the center line 11-01. The result of the combined irotary and wobbling movement is a :uniform polishing action at :the bottom portion of the cavity.

Referring now to movementof the tool 59 relatively to its chuck .I3it is apparent that the rocking of the cradle 28 by the amount E causes a tilting e of the tool axis relatively to the spindle axis, the tip of the tool remaining practically on the axis d-d of the jewel, except for the minute displacement e above referred to.

Referring now to the side polishing tool, it will be remembered that the tool H is of preferably circular cross section and rigidly mounted in its chuck 18. The point 8i of the tool is accurately ground to the angle a of the cavity. By reason of the rigid mounting of the tool ll, its larger cross section and shorter length, the point 8| of the tool makes a translatory movement e which is approximately equal to the amplitude of oscillation E of the chuck 13. During the polishing the point 8| of the tool H is displaced parallel to itself without tiltof the tool axis d-d rela- I tively to the jewel-axis, thus producing a most accurate polishing movement maintaining the side walls of the cavity perfectly straight.

During the polishing the tool ll makes a slight movement into and out of the cavity by an amount j which is taken up by the floating mounting of the work spindle l3 and its spring 20. This additional movement makes the polishing action most effective in removing circular grooves in the cavity sometimes caused by the tool by which the cavity was ground.

It will be apparent from the foregoing that the present invention provides a machine by means of which large numbers of jewels may be polished with utmost precision and uniformity never attainable by conventional hand polishing methods. The polishing time is extremely short and of the order of thirty seconds for either tool assuming the material of the jewels to be sapphire.

'si-Ve to produce, easy to set up and adjust and :simple to operate. The novel device may be op- .eratedby unskilled workers and will produceresultswhich are vfar superior to the bestmanual performance of highly skilled jewel workers.

While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that various omissions, substitutions'and changes may .be made by those skilled inthe art without departing from the spirit :of the invention.

What isclaimedis:

l. A polishing :machinefor V cavities injewels comprising, in combination; a rotatable chuck for holdingthe jewel; a-spindle mounted for r0- tation with its axis normally coaxial with said chuck with freedom of oscillating movement about an axis parallel to the axis of said chuck; means for rotating the chuck and said spindle in opposite directions; and means including an oscillating support for the spindle for periodically displacing said spindle to either side of the chuck axis while maintaining the spindle axis parallel with the chuck axis.

.2. A polishing machine for V cavities in jewels comprising, in combination, a spindle mounted for rotation about its axis and for displacement to eitherside of its axis; a floating chuck for holding the jewel, the chuck being mounted for rotation substantially coaxially with the normal position of said spindle and for axial displacement towards, and away from, said spindle;

means for urging the chuck towards said spindle; means for rotating said chuck and said spindle in opposite directions; and means including a pivoted spindle support for periodically displacing said spindle to either side of the chuck axis while maintaining the axis of said spindle parallel to the chuck axis.

3. A polishing machine for V cavities in jewels comprising, in combination, a base; a first spindle mounted in said base for rotation about its axis and for axial displacement; a spring urging said spindle in an axial direction; a chuck on said first spindle for holding a jewel; a bar mounted in said base parallel to said first spindle; a cradle pivotally mounted on said bar for rocking movement; a second spindle mounted in said cradle for rotation about its axis substantially coaxially with said first spindle; means carried by said second spindle for holding a polishing tool; means for rotating said spindles in opposite directions; and means for periodically rocking said cradle about said bar.

4. A polishing machine for V cavities in jewels comprising, in combination, abase; a first spindle mounted in said base for rotation about its axis and for axial displacement; a spring urging said spindle in an axial direction; a chuck on said first spindle for holding a jewel; a bar extending through said base parallel to said first spindle; means for adjustably clamping said bar in said base; a cradle pivotally mounted on said bar for rocking movement; a second spindle mounted in said cradle for rotation about its axis substantially coaxially with said first spindle; means carried by said second spindle for holding a polishing tool; means for rotating said spindles in opposite directions; and means for periodically rocking said cradle about said bar.

5. A polishing machine for V cavities in jewels comprising, in combination, a base; a first spindle mounted in said base forrotation about its axis and for axial displacement; a spring urging said spindle in an axial direction; a chuck on said first spindle for holding a jewel; a bar mounted in said base parallel to said first spindle; a cradle pivotally mounted on said bar for rocking movement; a second spindle mounted in said cradle for rotation about its axis substantially coaxially with said first spindle; means carried by said second spindle for holding a polishing tool; an eccentric including means for adjusting its eccentricity; meansfor driving said spindles in opposite directions and fordriving said eccentric; and a rod hinged to said cradle and connected to said eccentric for rocking said cradle.

' 6. A polishing machine for V cavities in jewels connecting said cradle with said eccentric for rocking the cradle about its pivotal axis; and joint means for driving said spindles in opposite directions and for driving said eccentric.

7. In a polishing machine for V cavities in jewels the combination with a rotatable jewel chuck and a rotatable tool chuck; one of said chucks being periodically displaceable while at all times maintaining its axis parallel tothe axis of the other chuck, of a non-metallic bottom polishing tool held in the tool chuck for rotation therewith and with freedom-of tilt relatively thereto, one point of the tool corresponding substantially to the shape of the V in the jewel v to be polished.

8. In a polishing machine for V cavities in jewels the combination with a rotatable jewel chuck and a rotatable tool chuck, one of said chucks being periodically displaceable while at all times maintaining its axis parallel to the axis of the other chuck, of a wooden bottom polishing tool held in the tool chuck for rotation therewith and with freedom of tilt relatively thereto, the point of the tool being of greater width'than thickness and corresponding substantially to the shape of the V in the jewel to be polished.

9. In a polishing machine for V cavities in Jewels the combination with a rotatable jewel chuck and a rotatable tool-chuck, one of said chucks being periodically displaceable while at all times maintaining its axis parallel to the 'axis of the other chuck, of a non-metallic relatively rigid side polishing tool held in the tool "chuck, the point of the tool being of circular'cross section and corresponding in shape to the Vinthe jewel to be polished. r

10. In a polishing machine for V cavities in jewels the combination with a rotatable jewel chuck and a rotatable tool chuck, one of said chucks being periodically displaceable while at all times maintaining its axis parallel to the axis of the other chuck, of a wooden relatively rigid side polishing tool of substantially circular cross section held in the tool chuck, the point of the tool being shaped to correspond to the V in the jewel to be polished.

LOUIS C. BLANCHON. i

Images