WAX RING PATTERN MACHINING TOOL

Abstract: A wax ring pattern machining tool (10) which enables a goldsmith to create a precision machined wax ring pattern for subsequent casting in precious metal by the lost wax process, the machining operations on the ring pattern being carried out while the pattern is still a part of a wax ring preform tube (110), said machining tool (10) being employed to create circumferential grooves or channels on the exterior of the ring pattern or to reduce the diameter of the ring tube or otherwise shape it circumferentially.

Description: The present invention relates to the precision machining of wax ring patterns for rings which are subsequently to be cast in precious metals by the lost wax investment casting process. Heretofore the forming of wax ring patterns was a manual process, involvng the free-hand carving of the pattern by the jewelwer of goldsmith and uniformity of the pattern was difficult to achieve. In a previous disclosure, now U.S. Patent 4,626,145, which is fully incorporated herein by reference, I disclosed a wax ring preform sizing tool which the goldsmith could employ to size the interior of a wax ring pattern to a precise ring size with perfect concentricity with the outside of the pattern. The present invention discloses an improvement on that tool and adds indexing and machining functions which enable the goldsmith to index the tool in fixed radial positions, to file precise flat surfaces on the exterior of a wax ring preform, and to perform a variety of machining operations on the exterior of a wax ring pattern while the ring pattern is still a part of a wax ring preform tube. The tool enables the goldsmiths to work on a wax ring pattern with machine shop precision with a simple hand tool. No tools designed exclusively for working on wax ring patterns have been available to the trade before the invention of the wax ring preform sizing tool cited in the above referenced patent. The goldsmith began his operations to form a wax pattern by starting with a wax ring preform tube, a cylinder of wax having a bore size smaller than the smallest ring size. Wax ring preform tubes are supplied to the trade as cylinders from 6 to 12 inches long which may have bores which are not concentric with the exterior of the preform e.g., cylinders with non-concentric bores or preforms having an extended flat surface. A wax ring pattern the width of the ring was cut from the preform and tube and the goldsmith then proceeded to fashion a wax ring pattern by caving and shaping the ring desired design and sizing the interior of the ring pattern to the required ring size using free hand carving and shaping techniques. The reference patent disclosed a tool which would size the interior of a wax ring pattern to the correct finger size while it was still a part of the wax ring preform. The present invention provides a pilot guided, indexable wax ring pattern machining tool which permits the goldsmith to machine the exterior of a wax ring pattern while it is still a part of the wax ring preform tube. The tool provides the goldsmith with the capability of indexing the tool in fixed radial positions, freely rotating the tool in order to perform various turning, shaping, faceting and drilling operations on the exterior of the wax ring pattern attached to the ring preform tube. The present invention discloses a pilot guided tool holder held at one end of a wax ring preform tube and connected by a shaft through the bore of the tube to a base plate inserted in the other end of the preform tube. An indexing gear secured to the shaft maintains the base plate in position and an indexing set screw may be used to engage a tooth on the gear to fix the tool holder in a fixed radial position. A slot in the body of the tool holder accepts a variety of L-shaped tool supports for holding tools for machining the exterior of the way ring pattern. The tool support arms are secured in the slot by tightening the operating handle of the tool. With the indexing set screw disengaging, the tool is free to rotate and scraping, carving, or shaping tools attached to the tool supports may be employed to scrape or cut the exterior of the wax pattern to a desired pattern. When the exterior of the pattern has been completed the tool support is removed and the scraping blade of the tool is inserted in the slot and used to size the interior of the ring and to separate the ring pattern from the wax ring tube preform. Fig. 1 is a side view showing the wax ring pattern machining tool with an indexing attachment installed on the wax ring preform tube which is shown in section. Fig. 2 is a perpective view of the base of the indexing attachment. Fig. 3 is a perspective view of a graving tool support and graving tool. Fig. 4 is a perspective view of the machining tool as it used with the graving tool to make grooves in the ring pattern. Fig. 5 is a perspective view of a flat blade tool support and scraping blade. Fig. 6 is a perspective view of the machining tool as it is used with the flat blade to reduce the outside diameter of the ring pattern. Fig. 7 is a perspective view of the tool with a faceting attachment and indexing attachment shown installed on a wax ring perform. Fig. 8 is a top view of showing the faceting operation on a ring pattern. Fig. 9 is a side view of showing the positioning of the file guide rollers of the faceting tool. Fig. 10 is a side view showing the scraping blade for sizing the interior of the pattern. Fig. 11 is a perspective view showing the machine tool employed with the scraping blade to size the ring and separate the pattern from the preform. Referring now to the drawings in which like numbers refer to like parts and now to Fig. 1 there is shown a wax ring pattern machine tool 10. A tool holder 11 is provided with a body 12 having a pilot member 14 which extends into the bore of the wax ring pre­ form tube 110. A knurled section 19 on the end of pilot member 14 permits the pilot member to precisely size the bore of the preform tube to accomodate the tool. While wax preform tubes are supplied with a nominal bore of .065", small variations do occur during the forming process and the knurled section scrapes a uniform bore for operation of the tool as it is inserted into the bore of the ring preform tube. The body of tool holder 11 is provided with a slot 15 for re­ ceiving tools and tool supports which are secured in position by tightening operation handle 16 screw 17. A shalt 18 is threaded into pilot member 14 and secured in a place by tightening nut 20. Shaft 18 extends through the bore of preform tube 110 and beyond the end thereof. A base member 22 is installed on the shaft and moved until the base pilot member 24 enters the bore of the preform tube and the base 26 is in contact with the end of the ring preform tube. Small teeth 28 on the base are forced into the end of the preform tube preventing the base member from rotating. An indexing set screw bracket 30 on the base 26 holds an extending set screw 32. An indexing gear 34 is instal­ led on the shaft and moved into engagement with the base and secured in that position by tightening set screw 36. Referring now to Fig. 2 the assembly details of the indexing mechanism are shown. A tool support arm 42 may be inserted through slot 15 in the tool, supported away from the end of the wax preform tube by spacer ring 44 and secured in place by tightening the operating handle 16. The spacer ring may be provided with a slot 45 to enable the goldsmith to observe a ring size marking made on the end of the ring tube preform. The tool support arm 42 provides the means for holding and positioning a variety of tool supports and tools for machining the exterior of the wax ring pattern by attachment to the support arm L 46. Referring to Fig. 3 there is shown a graver blade tool support 50 which holds a graver blade and may be used to cut grooves or channels on the exterior of the pattern. The graver blade support is positioned at the desired vertical position on the tool support arm L 46 and secured in position by tightening set screw 54. A graver blade 52 which may have any desired shaped cutting edge is secured in the graver blade support by set screw 56. With the graver blade support and blade on the support arm L the goldsmith may, by rotating the tool and moving the graving tool into engagement with the wax preform tube, cut grooves, channels and make other narrow cuts on the exterior of the pattern as shown in Fig. 4. Referring to Fig. 5 there is shown a flat blade tool support 60 which holds a flat scraping blade 62. Flat blade tool support 60 is positioned on tool support arm L 46 and secured in the desired vertical position by tightening set screw 64. A flat blade 62 which may have a straight or rounded cutting edge is secured in the support by tightening set screw 66. With the flat blade tool support installed on the tool, the goldsmith can reduced the outside diameter of the ring pattern or make curved surfaces on the pattern depending upon the cutting blade shape, as shown in Fig. 6. The foregoing free-turning operations are performed with the indexing set screw 32 disengaged from the indexing gear or they may be performed with the indexing tool removed from the tool holder. The attachments to be described are employed with the indexing tool to precisely index the tool holder in fixed radial positions. Referring now to Fig. 7 there is shown a faceting tool 70 which provides the goldsmith with the capability of machining flat surfaces on the exterior of the ring pattern. The tool support arm is removed from the tool holder and a faceting tool arm 72 is installed and secured in position by the operating handle 16. A rotatable collar 74 is provided with a slit 76 so that tightening lock screw 78 on the faceting tool arm secured the rotatable collar in a fixed radial position. Indicia 80 on the faceting tool arm permit the setting of precise angles of the rotatable collar. A support arm 82 is inserted through the rotatable collar and supports file guides 84 which have extending file guide rollers 86. File guides 84 may be positioned along the support arm and secured in position by tighte­ ning set screws 88. Referring now to Fig. 8 there is shown the method of operation of the faceting tool. The file guides 84 are positioned to straddle the wax preform and the faceting tool arm is adjusted to provide a chord of the desired width across the surface of the wax pattern. A file 120 is then employed to file the pattern until the file engages the file guide rollers 86 which prohibit further inward movement of the file. The tool may then be re-indexed, using the indexing gear and set screw, and the filing operation repeated, if desired. Fig. 9 shows the rotatable movement of the collar 74 which positions the file guide rollers at an angle to the axis of the preform tube and wax pattern, permitting the filing of faceted, beveled flat surfaces on the ring pattern. The indexing attachment also permits the use of other attachments with the holding tool to perform operations which require that the tool be fixed in position. Operations such as drilling and cutting axial grooves in the ring pattern may be performed using suitable tool supports and tools. Referring now to Fig. 10 there is shown a scraping blade 100 which is employed to dimension the bore of the wax pattern to the desired ring size. Indicia 102 which are identified as ring sizes to permit the goldsmith to set the blade in the tool holder to secure a desired internal diameter of the wax ring pattern. Fig. 11 shows the use of the scraping blade in the tool holder to dimension the bore of a completed ring pattern. Having described the elements of the wax ring pattern machine tool the procedure for fashioning a ring pattern from a wax ring preform tube will be described. The goldsmith first employs the tool with the scraping blade installed as shown in Fig. 11 to make a small reference cut on the end of the preform tube showing the ring size. The scraping blade is then removed and the tool support arm 42 and spacer ring 44 are installed on the tool. The graver tool support and graving tool are installed on the tool support arm 46 and are used to make a channel cut in the ring preform tube to define the width of the ring pattern as shown by 112 in Fig. 1. The channel is cut is made slightly deeper than the ring size as shown by the reference cut. The goldsmith then employs the various tool supports and tools to configure the outside of the ring to the desired pattern. When the machining of the exterior design of the ring pattern has been completed, the scraping blade is re-installed and used to dimension the interior or the pattern. The wax ring pattern separates from the ring preform tube when the scraping blade reaches the channel cut 112 which was made as the second step in the ring making process as may be seen in Fig. 11.

Claims: 1. A tool (10) for machining wax ring patterns from wax ring preform tubes while the ring pattern is part of the tube which comprises : a tool holder (11), having a body portion (12) provided with a trans­ verse slot (15) therein for received tools and tool supports and a pilot portion (14) for insertion into the bore of one end of a wax preform tube (110), said pilot portion (14) provided with knurling (19) to dimension the bore for the tool holder (11); and operating handle (16) extending from the end of said body by screw attachment said screw passing to the transverse slot (15) in the body for securing tools or tool supports therein; indexing means for positioning the tool holder (11) in fixed radial positions or allowing free rotation of the tool holder (11); shaping means for circumferentially machi­ ning the external surface of the wax ring pattern; faceting means for creating flat or beveled surfaces on the exterior of the wax ring pattern and dimensioning means for sizing the interior of the wax ring pattern. 2. The tool according to claim 1, characterized in that the indexing means comprises a base member (22) for enga­ gement with the opposite end of the ring tube preform (110), said base member (22) provided with a base (26) for engagement with the ring preform tube (110) and a pilot member (24) for engagement with the bore of the tube (110), said base (26) having small teeth (28) for engagement with the end of the tube preform (110), a shaft (18) extending from the pilot portion (14) of the tool (10) through the base member (22), an indexing gear (34) secured to said shaft (18) in contact with the base (26) and an indexing set screw (32) attached to said base (26) for engagement with tooth of the gear (34) so that with the indexing set screw (32) in engagement with the indexing gear (34) the tool (10) is fixed in a radial position and with the set screw (36) disengaged from the gear (34) the tool (10) is free to rotate. 3. The tool according to claim 1, characterized in that the shaping means comprises a tool support arm (46) having an L shape, one leg of the support arm (46) being fixed in the tool holder (11) and the other leg extending along the axis of the preform tube; tool supports attachable to the tool support arm for supporting tools for machining the exterior of the wax ring preform (110) and tools for engagement with the preform (110) so that when the tool holder (11) is rotated the tools shape the exterior of the ring pattern. 4. The tool according to claim 3, characterized in that the tool support is a graving tool support (50), the tool is a graving tool and the operation of the tool holder (11) permits cutting grooves or channels in the ring pattern. 5. The tool according to claim 3, characterized in that the tool support is a flat blade holder (60), the tool is a flat scraping blade (62) which may have a contoured scraping edge and operation of the tool holder (11) permits reducing the diameter of the ring pattern or shaping the pattern along its full width. 6. The tool according to claim 1, characterized in that the faceting means comprises a faceting tool arm (72) inserted in the tool holder (11), said faceting tool arm (72) having a rotatable collar (74) at one end thereof; a support arm (82) extending through the rotatable collar (74), a file guide (84) positionable along the support arm (82) on each side of the faceting tool arm (72) and file guide rollers (86) extending from the file guides (84) along the axis of the ring preform tube (110) so that when the file guide rollers (86) are positioned to straddle the preform tube (110) and the faceting tool arm (72) is positioned to define a chord across the ring pattern a file may be used to file a flat facet on the pattern until further inward movement of the file is prevented by engagement with both file rollers (84). 7. The tool according to claim 6, characterized in that the rotatable collar (74) serves to position the file guide rollers (86) at angles to the axis of the ring pattern and the filing operation creates beveled surfaces on the ring pattern. 8. The tool according to claim 1, characterized in that the dimensioning means comprises a scraping blade (100) for insertion in the tool holder (11), said blade (100) having indi­ cia (102) showing jeweler's ring sizes for setting the radial position of the blade (100) so that rotation and axial translation of the tool holder (11) causes the scraping blade (100) to enlarge the bore of the wax ring tube perform (110).

Inventors: VASQUEZ, EDUARDO
Applicants: VASQUEZ, EDUARDO
Application year: 1987
Main classification: B22C7
IPC codes: B23B5