US3435569A

US3435569A - Faceting apparatus

Info

Publication number: US3435569A
Application number: US493041A
Authority: US
Inventors: Howard E Stanley
Original assignee: HOWARD E STANLEY
Current assignee: HOWARD E STANLEY
Priority date: 1965-10-05
Filing date: 1965-10-05
Publication date: 1969-04-01
Anticipated expiration: 1986-04-01

Description

A ril 1, 1969 H. E. STANLEY 3,435,559

FACETING APPARATUS Filed Oct. 5, 1965 Sheet of 2 I\\\\\\\ I 3/ INVENTOR.

30 j Harmer STANLEY JZ- BY 8 W 7 April 1, 1%9 H. E. STANLEY 3,435,559

FACETING APPARATUS Filed Oct. 5, 1965 Sheet 3 of 2 331g 27 in"? FIG. I: QZQ 0 //f///f////// I INVENTOR. flow/RD Smwzzr WM/y ATTORNEY United States Patent (jflice 3,435,569 Patented Apr. 1, 1969 3,435,569 FACETING APPARATUS Howard E. Stanley, 1545 E. Catalina, Santa Ana, Calif. 92701 Filed Oct. 5, 1965, Ser. No. 493,041 Int. Cl. B24b 19/00 US. Cl. 51229 11 Claims ABSTRACT OF THE DISCLOSURE A faceting apparatus which includes a vertical post supporting for vertical movement an elevation block, which in turn supports on a generally vertical swinging axis a link, or yoke, which in turn supports on a horizontal axis for swinging movement a chuck block which carries a chuck rotatively mounted therein, and there is pdovided pawl means for selectively locking the chuck in desired positions relative to the chuck block, and further there is provided a clutch assembly adapted to limit the downward movement of the chuck at a desired point, but will not prevent upward movement of the chuck.

This invention relates to faceting apparatus and more particularly to faceting heads having provision for accurately positioning a gem to be faceted.

Apparatus for grinding facets on gem stones customarily include a lap, i.e., a flat disc having an abrasive material disposed on it, which disc is rotated by some means such as a motor. Then the gem is carefully positioned against the lap in order to accomplish the grinding and polishing operation. Customarily, the gem is held in a chuck which is supported by a faceting head having means to permit the chuck to be swung about a vertical axis, and about a horizontal axis, as well as about the longitudinal axis of a chuck. In addition, the head includes means to permit the chuck to be elevated or lowered along a vertical axis. By this means, the gem may be positioned against the lap in almost any desired orientation.

Diiferent grinding com-pounds are used for different purposes. For example, a coarse compound is used when the operator is making his initial cuts to bring the facets into the desired shape. However, for the final polishing operation, it is desired to use a compound of finer qualities. Therefore, it is very desirable that the faceting head be able to permit the operator to grind the various facets with the coarse compound, and then reorient the gem as needed to polish each of the facets. Accordingly, and important aspect of the present invention is that faceting heads made in accordance with the present invention enable the operator to accurately reposition the gem to any previous position.

Another important aspect of the present invention is the provision of easily read means for accurately indicating the angle to vertical, that the gem is held.

In the positioning of the gem against the lap, it is sometimes necessary to position the whole faceting head relative to the base of the faceting apparatus. Accordingly, another important aspect of the present invention is the provision means to allow the faceting head to be quickly moved on the base and secured, or anchored, at the new point.

Faceting heads made in accordance with the present invention are precision devices whereas the lap wheel and the rest of the apparatus is relatively indestructable to the elements. Accordingly, a further important aspect of the present invention is that the faceting head may be easily removed when not in use for stowage in a protected area separate from the relatively immovable remaining portion of the faceting apparatus.

In prior faceting apparatus, there has been provision to permit the gem holding chuck to be selectively rotated about its longitudinal axis. And accordingly, there has been provided for this purpose a chuck index gear secured to the chuck with a pawl on the chuck block to selectively engage the gear to lock the gear. However, such units have had the disadvantage that the adjustment is limited to the distance between two teeth on the index gear. Accordingly, it is another important aspect of the present invention to provide means for permitting smaller adjustment of the rotary position of the chuck than in the past.

Still another important aspect of the present invention is provision of means to permit the index gear pawl to be locked out of engagement and then easily released to return to the engaging position to lock the index gear.

While faceting, the operatior will quite often want to lift the gem from the lap in order to inspect the gem facet being lapped, and then return the gem to the operating position. To accommodate this need, another important aspect of the present invention is the provision of means to stop selectively the downward swing of the chuck, but which means permits the chuck to be lifted for the inspection purposes.

A further aspect of the present invention is the provision of means to permit the chuck to be very easily swung from side to side around the generally vertical axis with provision of means to selectively tilt the vertical axis slightly from vertical. Therefore, by tilting the vertical axis in the proper direction, the weight of the chuck and gem will cause the stone to swing toward the center of the lap. Since the chuck remains at the same angle to the lap, the swinging motion will lower the gem into the lap. Accordingly, with this arrangement, the chuck and gem will gradually swing toward the center of the lap as the gem is ground. Therefore, by stopping the grinding process as the gem reaches the predetermined distance from the center of the lap each time a facet is ground, the facets will be uniformthus facilitating the faceting operation.

With the foregoing in mind, it is a major object of this invention to provide a more easily used faceting head.

It is another object of this invention to provide a faceting head which has provision for accurately repositioning the gem for further polishing of a previously ground facet.

Another object of this invention is to provide a faceting head which may be easily removed from the remaining portion of the faceting apparatus.

Afurther object of this invention is to provide a faceting head which will permit very small adjustments of the rotary position of the chuck.

Still another object of this invention is to provide a faceting head having means to permit the chuck index gear locking pawl to be locked out of engagement with the gear, and then quickly released to return to the engaging position to lock the chuck index gear.

A still further object of this invention is to provide a faceting head having an elevation block supporting the chuck, and means for accurately indicating the height of the elevation block above the lap.

Still another object of this invention is to provide a faceting head wherein the gem holding chuck may be swung about a generally ventical axis and means are provided to tilt that axis of swing slightly from vertical.

It is a still further object of this invention to provide a faceting head having a chuck whidh may be swung about a generally horizontal axis and which faceting head has means for easily and accurately positioning the chuck to the desired angle to the lap.

Other and further objects of this invention will become apparent in the detailed description below in conjunction with the attached drawings wherein:

FIG. 1 is a perspective view of a preferred embodiment of my new faceting apparatus;

FIG. 2 is an enlarged cross-sectional view of a portion of the faceting head taken along line 22 in FIG. 1;

FIG. 3 is an enlarged fragmentary cross-sectional view of the base of the post of the faceting head taken along line 33 in FIG. 1;

FIG. 4 is an enlarged fragmentary view of the side of the post of the faceting head;

FIG. 5 is a partially cut-away elevation view of the faceting head disclosed in FIG. 1;

FIG. 6 is an enlarged fragmentary cross-sectional view taken along line 6-6 in FIG. 2;

FIG. 7 is an enlarged fragmentary cross-sectional view taken along line 77 in 'FIG. 1;

FIG. 8 is an enlarged fragmentary view taken along line 88 in FIG. 7;

FIG. 9 is an enlarged fragmentary view of the angle indicator dial of the apparatus;

FIG. 10 is a frontal view disclosing the manner of engagement of the chuck index gear and pawl taken along line 1010 in FIG. 5;

FIG. 11 is an enlarged fragmentary cross-sectional view of the means for latching the chuck index gear pawl out of engagement taken along line 11-11 in FIG. 1;

FIG. 12 is an enlarged fragmentary cross-sectional view of the' means for adjusting the chuck index gear pawl taken along line 12--12 in FIG. 5; and,

FIG. 13 is an enlarged fragmentary view taken along line 1313 in FIG. 12.

Referring now to the drawings there is shown a preferred faceting head, indicated generally by the arrow 10, made in accordance with the present invention. The faceting head 10 is restintg on a base plate 11 and is secured by a means to be described. Disposed to the left (as seen in FIG. 1) is a lap 12 which rotates on a spindle 13, which spindle is driven by a motor 14 through means such as a belt which is not shown. Grinding compounds and liquids, such as water, are used in the faceting operation. Accordingly, a conventional splash pan 15 is provided.

Generally speaking, the faceting head 10 includes an upstanding post 18 which has an elevation block, or carriage, 19 disposed thereon for vertical movement. The means by which the elevation block 19 is moved up and down will be described in further detail below.

A link, or yoke, 20 is secured to the elevation block 1 9 for movement about a generally vertical axis by means which will be described in greater detail below. At the end opposite the elevation. block 19, the yoke 20 carries a chuck block, or gimbal, 21. As will be described in greater detail below, the chuck block 21 is mounted so as to permit it to swing about a generally horizontal axis. The generally horizontal axis is perpendicular to the generally vertical axis about which the link 20 swings.

A chuck 22 is rotatably carried by the chuck block 21 as will be described in further detail below. However, at this time it should be noted that the chuck 22 removably holds a dop 24 to which a gem, or gem stone, 25 is secured by an appropriate adhesive. In order to facilitate the handling of the chuck 22, a handle 26 is secured to the chuck block 21 and extends at an acute angle to the axis of the chuck 22. As will be described in greater detail below, the operator uses the handle 26 during the selection of the particular orientation of the chuck 22 around its axis.

Before going on with the detailed description of the preferred embodiment of the invention the overall operation will be described generally at this time. Firstly, the chuck 22 may be rotated about its longitudinal axis in the chuck block 21 in order to place any one of the triangular shaped facets on the gem 25 against the lap 12. The means for properly indexing the various facets will be discussed further below. Additionally, the chuck 22 may be swung upwardly away from the lap 12 about the aforementioned generally horizontal axis. Therefore, if it is desired to decrease the angle between the chuck 22 and the lap 12, the chuck 22 may be swung (by means to be described) to the desired angular relation, and then the elevation block is lowered until the gem 25 is moved into grinding position against the lap 12. If it is desired to increase the angle between the chuck 22 and the lap 12, the elevation block 19 is raised (by means to be described). Then the chuck 22 is swung to the steeper angle, and the elevation block 19 is lowered again.

As mentioned above, it is desirable that the faceting head 10 may be quickly positioned and then anchored to the base 11. To this end the slot 27 is provided in the base 11, which slot has an enlargement 28 at one end thereof. The post 18 has a post base 29 upon which it rests on the base plate 11. Extending through the post base 29 is a crankshaft 30 having a throw, or offset portion, 31 (see FIG. 3). Secured to the throw 31 is a clamp bolt 32 having a clamp washer 33 at its lower end. Therefore, by turning handle 34 (see FIG. 1) the shaft 30 is rotated so as to raise the clamp bolt 32 to a position where clamp washer 33 engages the underside of the base plate 11. It will be noted that the clamp washer 33 is positioned so that the throw 31 is almost directly above the main axis of the shaft 30 when the washer is engaging the underside of base plate 11. Therefore, the crankshaft 30 will remain in the clamping position because of the friction between the parts.

In order to remove the faceting head 10' from the apparatus, the handle 34 is turned to loosen the clamp washer 33. Then the head is moved to a position where the clamp washer 33 may be passed up through the enlargement 28. At this time, the faceting head 10 may be stored in some suitable place where it may be kept clean. On the other hand, the rest of the faceting apparatus, which is relatively removable, may remain in its position in the shop.

The means for raising and lowering the elevation block 19 will now be described. There is provided a lead screw 36 which is rotatably mounted at its lower end at the lower end of the post 18 while the upper end of the screw extends through the upper end of the post. The elevation block 19 is secured to the lead screw 36 by the means of a threaded bearing 37, and therefore, the elevation block is moved up or down by rotataion of the screw. To this end, there is provided at the upper end of the lead screw 36 a crankwheel 38 having an offset handle 39.

For the purpose of indicating an approximate height of the elevation block 19 there is provided a scale 40 secured to the side of the post 18. As can be seen in FIG. 4 the scale 40 has a series of marks 41 (which are spaced of an inch apart in the present commercial embodiment of the invention). It will be noted that there is a reference mark 42 afiixed to the elevation block 19.

As it is so important that the elevation of the elevation block 19 be accurately indicated (in order that the faceting head may be returned to that condition at a later time) there are provided means for indicating the angular relation of the lead screw 36. To this end, there is provided a series of marks 43 on the crankwheel 38 and a reference mark 44 on the upper end of the post 18. In the present commercial embodiment the lead of the lead screw is such that the elevation block is moved A inch each time the lead screw 36 is rotated 360. Accordingly, by evenly distributing marks 43 around the: crankwheel 38 the elevation block 19 may be relocated within of an inch. Therefore, the linear markings of scale 40 gives an approximate height of the elevationblock 19 whereas the angular indicator marks 43, in combination with the linear markings, give a precise indication based on the approximate indication. Further, it should be borne in mind, that the exact elevation of block 19 as such is not important. The important thing is that,

the present apparatus enables the operator to take a reading, e.g., 1.1 plus on the scale 40 and a reading of 0.080 on the markings 43 and combine them to obtain an accurate reading of 1.180. Thereby, if he should later desire to return the block 19 to that position for purposes of, for example, further polishing a facet, he may accurately reposition the elevation block 19.

Once the elevation block 19 is in the desired position, it is desirable to secure the block 19 in that position. To this end, there is provided an elongated slot 46 through the post 18. The block 19 carries a threaded stud 47 extending through the rear side thereof (to the right as seen in FIGS. 1 and 2), and the anchoring operation is completed by tightening knurled nut 48 on to the threaded stud 47.

At this time, the preferred manner of swingably securing the link, or yoke, to the elevation block 19 will be described. Referring now to FIGS. 1, 2 and 6 in particular, the elevation block 19 is provided with upper and lower clevis portions, 50 and 51 respectively, which have a portion of the link 20 therebetween. As can be seen in FIG. 6, a ball bearing 53 has its outer race press fitted into the lower side of the link 20 while its inner race receives a short rod 54 in press fit relation. The short rod 54 has an annular flange 55 which is of larger diameter than hole 56 through lower clevis portion 51. It should be noted that the hole 56 is of slightly larger diameter than the rod 54 in order to allow the slight tilting motion which will be described just below.

The upper side of the link 20 is secured in the following manner. A ball bearing 57 has its outer race press fit into the upper side of the link 20, A rod 58 has its lower end press fit into the inner race of the ball bearing 57 with annular flange 59 resting against the upper side of the inner race of the ball bearing. It should be noted that hole 60 in the upper clevis portion 50 is also substantially larger than the rod 58. This is to allow the upper end of the link 20 to be positioned laterally in order that the axis about which the link 20 swings may be adjusted to vertical, or tilted slightly from vertical as desired. The actual adjustment is accomplished by a pair of adjustment screws 61 which hold the rod 58 in conjunction with spring 62. The adjustment is accomplished by screwing in or screwing out either or both the screws 61. It should be noted that instead of two springs 62, the adjustment could be permitted also if only one spring 62 were provided at a point halfway between the two springs shown. Preferably, the screws 61 are approximately 100 apart.

As mentioned previously, the chuck 22 is swung about a generally horizontal axis which is at a right angle to the generally vertical axis just described. To this end, the link 20 is bifurcated at the end opposite the block 19 to provide left hand arm 64 and right hand arm 65 between which the chuck block 21 is disposed. Referring now to FIGS. 1, 5 and 7 the manner in which the chuck block 21 is swingably disposed will be described in further de tail. As seen in FIG. 5 the chuck block 21 is provided with an annular projection 66 having a recessed area which receives in press fit relation the outer race of a ball bearing 67. A bushing 68 is received in press fit relation with the inner race of the ball bearing 67 while a threaded screw 69 secures the bushing 68 to the left hand arm 64. Because of the manner in which FIG. 5 has been cut away, the manner in which the screw 69 cooperates with the left hand arm 64 is not disclosed. However, since the cooperation between the screw 69 and the left hand arm 64 is so similar to the manner in which the opposite sides of the chuck block 21 i connected to the right hand arm 65, the cooperation between the screw 69 and the arm 64 will not be shown in further detail.

Referring now to FIG. 7, there is an angle dial drive gear 71 secured to the block 21 by plurality of screws 72. The gear 71 has a recessed area which receives in pressed fit relation the outer race of ball bearing 73. The ball bearing 73 has a bushing (not shown) such as the bushing 68, which bushing receives in threaded relation a screw 74 which is the counterpart of the screw 69.

With this arrangement, the chuck 22 may be swung about the axis passing through the centers of the screws 69 and 74. Further, it will be noted that the center of gravity of the chuck 22 and the block 21 is such that the chuck tends to descend by gravity.

As mentioned previously, it is extremely desirable that the angle of the chuck 22 (and therefore the gem 25 be accurately known in order that it can be repeated). To this end, an angle dial 75 is provided fixed to a shaft 77 journaled in the right hand arm 65. The shaft 77 has an angle dial driven gear 78 keyed thereto, which interengages the driving gear 71. To facilitate observation of the angle of the chuck 22, the driven gear 78 is substantially smaller than the driving gear. Preferably, the driving gear 71 is six times larger than the driven gear 78. Accordingly, the angle dial 75 will turn through 360 three times in the time that the chuck 22 swings 180 from a position straight up to a position straight down. Because the angle dial 75 turns so many times, there must be some double mar-kings such as can be seen in FIG. 1 where the numbers 30 and 90 identify the same mark. However, since the operator will know the general angle of elevation he knows which of the numbers indicated on the angle dial 75 are the correct ones.

In order to return the chuck 22 to the proper angle, there must be no backlash between the gears 71 and 78. This can be avoided by placing the two gears extremely close together to eliminate the backlash. However, I prefer that means such as spiral spring 79 which is secured to the shaft 77 and the arm 65 be used. The spiral spring 79 continuously urges the driven gear 78 in one direction, thus eliminating backlash.

In order to further facilitate accuracy, I provide a vernier reference marker 81 on the arm 65 adjacent to the markings on the angle dial 75. (See FIG. 9 in particular.)

While the angle dial 75 indicates the angular relation of the chuck 22 very well, means must be provided to easily position the chuck in the desired orientation. Preferably, this means takes the form of an annular clutch 83 having a nylon lining engaging the exterior surface of the annular projection 66. The clutch 83 has an arm 84 extending laterally from the generally horizontal axis about which the chuck 22 swings. And, as can be seen in FIG. 5, the chuck 22 may swing downwardly until the arm 84 engages the lower end of screw stop 85 threadedly received through the left hand arm 64. A knurled head 86 is provided at the upper end of the screw stop 85 to facilitate adjustment. Also, a small screw 87 is provided to adjust the friction between the clutch 83 and the projection 66.

In use, the operator holds his finger on the underside of the arm 84 pressing it against the stop 85. He then swings the chuck block 21 (overcoming the friction of the clutch 83) until he has the chuck 22 positioned at approximately the position desired. At that time, he makes the fine adjustment by turning the screw stop 85 in the appropriate direction while observing the angle dial 75.

As mentioned previously, the chuck 22 may be rotated around its longitudinal axis to provide faceting positions. To this end, the chuck 22 has a shaft 88 which extends through the chuck block 21. The shaft 88 is supported at its rear-ward end by a bearing in the bearing housing 89, and there is another bearing (not shown) in the chuck block immediately to the rear of chuck index gear, or wheel, 90. The index gear 90 has a series of markings on it in order to facilitate the faceting operation. For example, the index gear 90- has markings on it so that the operator can easily divide the 360 circle into three parts or six parts or eight parts or another number of parts.

Attention is particularly drawn to FIG. 10 wherein index pawl 91 for locking the index gear 90 is shown. It has been found that if only one tooth 92 were used, it tends to wear on the teeth of the index gear. This is because the index gear 90 is positioned in certain basic areas (for example at much more than other areas. Accordingly, the pawl 91 has a plurality of teeth 92 (preferably (five) which interengage with the teeth on the rim of the gear 90. By providing a plurality of teeth 92, a much more stable anchoring is effected by the pawl 91.

The index pawl 91 must be moved between a first position where it engages the teeth of the gear 90 and a second position where it is out of engagement with the teeth. To this end, the pawl 91 is secured to a rocker arm 94, and a spring 95 (see FIG. 11) engages the rocker arm 94 and continuously urges the pawl 91 towards said first position. In order to pull easily the pawl 91 towards the second position a release finger 96 is provided extending adjacent to, but spaced from, the handle 26. Therefore, the operator, while holding the handle 26, may easily grasp the release finger 96 to release the pawl.

As mentioned previously, it is sometimes desirable to latch the pawl 91 out of engagement with the gear 90, and then later release it. To this end, a latch 97 is swingably secured on pin 98 in the block 21 which latch 97 is biased counter clockwise (as seen in FIG. 11) by a spring 99. With this arrangement, the operator pulls the finger 96 toward the handle 26 against the force of the spring 95. Then the operator manually pushes the latch 97 to a position where it catches lip 100' on the rocker arm 94, and releases the finger 96. The force of the spring 95 holds the latch 97 in engagement with the lip 100. However, when the operator subsequently pulls up on the index finger (that is, when he pulls the pawl 91 in a direction away from said first position) the latch 97 is released and then swung away by the spring 99. At this time, the pawl '91 may be moved to engaging position by force of the spring 95 at the will of the operator.

As mentioned previously, an important feature of the present invention is that the angular orientation of the chuck 22 is not limited by the distance between any two teeth on the index gear 90. This advantageous result is preferably accomplished in the following manner. As can be seen in FIGS. 1, and 12, there is provided a pair of trunnions 101 secured to the chuck block 21. The trunions 101 each have a split threaded hearing which receives a pointed screw 102 which rotatably support a threaded axle 103 therebetween. For purposes which will be described it is desired that the threaded axle be rotated for adjustment purposes. Accordingly, a thumb wheel 104 is secured to the axle for such rotary purposes.

In FIGS. 12 and 13 it can be seen the rocker arm 94 is secured to the axle 103 by a threaded split bearing 106 secured to the rocker arm. The threaded split bearing 106 receives the threaded axle 103, and the two halves of the split bearing frictionally grip the axle so that the axle 103 will move with the threaded bearing 106 as the rocker arm 94 is swung to move the pawl 91 between the first and second position.

With this arrangement, the pawl 91 may be moved in the plane of the index gear 90 of the thumb wheel 104. This is because the rocker arm 94 cannot rotate with the axle 103 during the adjustment. Therefore, the split bearing 106 will move along the threaded axle as the thumb wheel 104 is turned.

Having described the detail of the preferred embodiment of the invention the advantages of tilting the axle about which the link 20 swing may be described with more particularity at this time. For sake of example, assume that the screws 61 are adjusted so that the upper rod 58 is pushed to the left (as seen in FIG. 6) so that the axis through the center of the rod 54 and 58 was slightly olf vertical with the upper end being to the left. In such condition, if the operator swung the chuck 22 to the right as seen in FIG. 1 it would be swinging at a slight incline and would tend to rise away from the lap 12. Conversely, if the operator swung the chuck left (in FIG. 1 this would be generally into the paper) the swinging movement would cause the chuck 22 to descend slightly. By having this accurate positioning of the axis of swing, and the free movement accompanying the use of the ball bearings, a new method of faceting is available with the use of faceting heads made in accordance with this aspect of the present invention. More particularly, assume for example that the operator sets the faceting heads so that the facet of the gem 25 engages the lap 12 approximately 3 inches from the center spindle 13. Then, as the lap 12 grinds away the gem, the chuck 22 may gradually swing towards the center of the lap 12. The progress of the gem 25 towards the center of the lap 12 is governed by the rate at which the lap removes the gem material. Then, assume further that the operator allows the lapping operation to continue until the gem 25 swings to a position, for example, one inch away from the spindle 13. At this time, the operator grasps the handle 26 and swings the chuck 22 upwardly. He then grasps the release finger 96 pulling it towards the handle 26. He then rotates the chuck the proper number of degrees to the new facet and releases the finger 96-whereupon the pawl 91 locks the index gear in proper position. The operator then moves the chuck 22 out to a position where the gem again is 3 inches away from the center of the lap 12. Then he allows the lapping operation to continue. As the lap 12 grinds away the material, the gem 25 will gradually progress towards the center spindle 13. When the gem 25 reaches the position one inch away from the center spindle 13, the operator lifts the gem 25 'by the handle 26 and repeats the process. Since the geometry of the apparatus remains constant, an equal facet stone would be generated.

While only a few modifications of the present invention have been shown and described in detail it will be apparent to those skilled in the art that such is by way of illustration only and numerous changes may be made thereto without departing from the spirit of the present invention. Accordingly, it is my intention that the invention be limited solely by the appended claims.

I claim:

1. In a faceting device:

a frame;

a chuck block mounted on said frame for swinging movement about a generally horizontal axis; a chuck journaled in said chuck block for rotation about a second axis;

an index wheel secured to said chuck for rotation therewith about said second axis; and

pawl means connected to said chuck block for selecttively locking said index wheel, said pawl means having a pawl movable between a first position engaging said index wheel and a second position out of engagement with said index wheel, said pawl means including:

a threaded axle rotatably mounted on said chuck block parallel to the plane of said index wheel;

adjustment means connected to said axle for receiving forces for rotating said axle;

a rocker arm having a threaded bearing connected to said axle by said threaded bearing, whereby the position of said rocker arm along said axle may be adjusted by rotating said axle; and

a pawl connected at one end of said rocker arm.

2. The invention set forth in claim 1 wherein means are provided for securing the axle against rotation after the adjustment operation.

3. In an improved faceting device;

a frame having an upstanding post;

an elevation block on said post;

a link carried by said elevation block; and

axle means connecting said link and said elevation block for swinging movement around a swing axis which is generally vertical, said axle means including 9 adjustment means operatively connected to said elevation block and said axle means for adjusting the relation of said swing axis to the elevation block; and a chuck connected to said link for holding a gem to be faceted.

4. The invention set forth in claim 3 wherein said axle means includes a generally vertically disposed axle on said link, and said adjustment means includes at least one screw for laterally displacing one end of the axle relative to the elevation block while the other end is maintained in its position relative to the elevation block.

5. The invention set forth in claim 3 wherein said axle means includes an axle having a rotary axis, and said adjustment means includes:

first and second screw means operatively connected to said elevation block and one end of said axle for individually dipslacing said one end relative to the elevation block at a right angle to said axis, said first screw means being oriented to displace said one end in a direction at a substantial angle to the direction in which said second screw means displaces said one end;

resilient means urging said axle one end against said screw; and

means operatively connected to said elevation block and the other end of said axle for maintaining said axle other end in its postion relative to the elevation block.

6. The invention set forth in claim 3 wherein said axle means is adjusted so that said swing axis is slightly nonperpendicular.

7. In a faceting device:

a frame; a chuck block mounted on said frame for swinging movement about a generally horizontal axis; a chuck journaled in said chuck block for rotation about a second axis;

paw] means connected to said chuck block for selectively locking said index wheel in a desired position, said pawl means including:

a pawl;

a rocker arm carrying said pawl at one end thereof, said rocker arm swingably mounted on said chuck block for movement between a first position where said pawl engages said index wheel and a second position where said pawl is out of engagement with said index wheel;

resilient means operatively connected to said rocker arm for continuously urging said arm toward said first position; and

latch means connected to said chuck block for selectively holding said rocker arm in said sec ond position, said latch means being adapted to release said rocker arm from said second position automatically in response to movement of said rocker arm away from said first position, whereby said rocker arm may be manually positioned and latched in said second position and then by manually moving the rocker arm further away from said first position the latch means will release and the rocker arm may be returned to said first position by said resilient means.

8. The invention set forth in claim 7 wherein said latch means includes a latch resiliently urged toward a release position out of engagement with said rocker arm, said latch being moveable by manual forces into engagement with said rocker arm, said latch being shaped so as to cooperate with the rocker arm and hold the latter in said second position.

9. In a faceting device:

a frame;

a chuck block mounted on said frame for swinging movement about a generally horizontal axis;

a chuck journaled in said chuck block for rotation about a second axis;

pawl means connected to said chuck block for selectively locking said index wheel in a desired position, said pawl means including:

a pawl;

a rocker arm carrying said pawl at one end thereof, said rocker arm having a threaded bearing connected to said axle by said threaded bearing whereby the position of said rocker arm along said axle may be adjusted by rotating said axle, said rocker arm being swingably mounted on said axle for movement between a first position where said pawl pawl engages said index wheel and a second position where said pawl is out of engagement with said index wheel; and

latch means for selectively holding said rocker arm in second position, said latch means being adapted to release said rocker arm from said second position automatically in response to a movement of said rocker arm away from said first position.

10. The invention set forth in claim 9 wherein means are provided for maintaining the axle in position after the adjustment operation, said means including means for clamping said threaded bearing against said axle.

11. In a faceting device:

a frame;

a chuck journaled in said chuck block for rotation about a second axis;

a handle secured to said chuck block, said handle disposed above said chuck;

an index wheel secured to said chuck for rotation therewith about a second axis; and

a pawl;

a rocker arm carrying said pawl at one end thereof, said rocker arm swingably mounted on said chuck block for movement between a first position where said pawl engages said index wheel and a second position where said pawl is out of engagement with said first index wheel;

a finger extending from said rocker arm generally parallel to but spaced from said handle for enabling a user to move the rocker arm away from said first position with the same hand that is holding said handle;

resilient means operatively connected to said rocker arm for continually urging said arm toward said first position; and

latch means for selectively holding said rocker arm in said second position, said latch means being adapted to release said rocker arm from said second position automatically in response to a movement of said rocker arm away from said first position.

(References on following page) References Cited 2,779,138 1/1957 Collar 51229 X 2,817,194 12/1957 Leiman 51 229 UNITED STATES PATENTS 3,088,729 5/1963 Marcus 269 97 3/1904 Marcher 517-229 3,128,578 4/1964 Ball 51 s5 7/1904 Sansfield 51-229 9/1919 Boerner 51-229 5 HAROLD D. WHITEHEAD, Primary Examiner.

7/1948 Weir 51-229