Economical stretchable precious-metal rings having enclosed annular voids
United States Patent Sager Apr. 15, 1975 541 ECONOMICAL STRETCHABLE 2,036,801 4/1936 Fitzgerald 29/4705 2,048,878 7/1936 Moldenhauer... 63/15 2,450,762 10/1948 Marshall. 63/l5.2  
 ENCLOSED ANNULAR vows 3,022,648 2 1962 Thaler 63/15 [75] lnventor: Bert W. Sager, Highland Park, 111.  
 [73] Assignee: Paramount Wedding Ring Co., Inc.,  
 Chicago, 111.  
 [22] Filed: Feb. 22, 1974 [21] Appl. No.: 444,828  
 [52] US. Cl. 63/15; 29/l60.6; 29/470.5; 29/475 [51] Int. Cl. A44c 9/00 [58] Field of Search ..63/l5,15.1,15.2,15.3, 63/l5.4; 29/160.6, 523, 470.5, 475  
 [56] References Cited UNITED STATES PATENTS 404,094 5/1889 Knight 63/15 1,192,983 8/1916 Brudercr 29/l60.6  
 1,327,606 l/1920 Bacharach 63/15.2  
 1,382,438 6/1921 Mestechkin 29/l60.6 1,442,240 l/l923 Stone 29/l60.6 1,822,392 9/1931 Esterman et al 63/l5.4 2,027,060 l/l936 Niven 631/15 Primary Examiner-F. Barry Shay Attorney, Agent, or Firm-Darbo, Robertson &amp; Vandenburgh [57] ABSTRACT An all-gold ring with substantial saving of gold, but which can be satisfactorily stretched to enlarge its size, is made by providing within the body of the ring narrow internal annular channels spaced apart by supporting ribs. A practical method of manufacture is to assemble and solder together an inner ring and an outer ring, the inner ring being grooved on its outer peripheral face. Gold solder paste of a character to match the ring is smeared on the inner surface of the outer ring. The inner ring is inserted while slightly undersize, so as not to scrape off the solder, and is then enlarged by stretching past its elastic limit to engage the outer ring firmly. The assembly is then heated, fuse-bonding the contacting surfaces throughout their areas.  
 4 Claims, 7 Drawing Figures INTRODUCTION The invention of which the present disclosure is offered for public dissemination in the event adequate patent protection is available relates to the economical manufacture of stretchable precious-metal rings. It is extremely desirable that precious-metal rings be stretchable from one size to a larger size. This is especially important in connection with rings which are to be held for sale byjewelers. becauseit greatly reduces the inventory which they must carry. There are also more rare occasions when a ring needs to be stretched to a larger size after being worn.  
  Economy in ring manufacture has been practiced heretofore in at least two ways. One is by making a ring which was concave on its inner face. Most people do not regard such a ring as attractive when it is off of a finger. The amount of precious metal which can be saved without such adverse side effects as forming grooves on the finger is relatively small. Also stretching these rings to a larger size without impairment of external appearance. due to collapsing is usually not practicable.  
  The other prior method of economy is to make hollow rings. However, these could not be stretched because attempts to stretch them would result in collapsing them. Accordingly this economy was practiced mainly in connection with rings made to order. such as class rings. where the need for stretching was relatively unlikely.  
  According to the present invention a substantial proportion of the precious metal. such as 25 percent, can be saved. and yet the ring can be stretched as satisfactorily as a solid ring. This is&#39; accomplished by providing separated annular channels or grooves internally of the body of the ring so that all of its outer surfaces are the same as with a solid ring. The annular channels are separated by ribs which reliably prevent collapse of the ring in the event of stretching. The ribs are of the same metal as the rest of the ring so that a l4-carat gold ring has no metal in it other than l4-carat gold.  
  Rings according to this invention are as satisfactory to the user as solid rings. but can be sold to jewelers at substantially lower cost. Because they can be stretched. the jeweler does not need to carry a more complete variety of sizes than he would with solid rings.  
  The advantages of the invention may be more fully appreciated by reference to the following description and to the drawings.  
 , DESIGNATION OF FIGURES FIG. I is a diagrammatic representation of the grooving of an inner ring on a lathe.  
  FIG. 2 is a diagrammatic representation of the application of gold solder paste to the inner surface of the outer ring and the slipping of the inner ring within it.  
  FIG. 3 is a diagrammatic representation of the stretching of the inner ring so that at its new size it will firmly engage the outer ring.  
  FIG. 4 is a diagrammatic representation of heating the composite ring of FIG. 3.  
  FIG. 5 is a diagrammatic representation of trimming the edges of the ring.  
  FIG. 6 is a perspective view of the finished ring. FIG. 7 is a diagrammatic representation of stretching the finished ring to be of a larger size if a larger size is needed.  
 INTENT CLAUSE Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding. this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose. as it is these that meet the requirement of pointing out the parts. improvements. or combinations in which the inventive concepts are found.  
 DESCRIPTION OF THE RING OF THIS INVENTION As seen in FIG. 6 the ring 11 of this invention has the appearance on all of its external surfaces of a solid precious-metal ring. Its-outer peripheral face may have any desired decorative treatment. It may be stretched to enlarge its size. as indicated in FIG. 7. Within its body, however, it is characterized by a reinforced hollowness resulting from a series of closely spaced annular grooves 12, separated by annular ribs 13. as seen in FIGS. 2 and 3. The ribs 13 are integral with one of the two ring-parts l6 and I7 which make up the final ring. and bear firmly on the other ring-part so that enclosed annular voids are formed by surfaces of the two ring parts. They are also thick enough and spaced at sufficiently close intervals so that they provide adequate reinforcement throughout the cross sectional area of the ring to prevent collapsing of the outer ring-part during stretching of the ring to enlarge its size as seen in FIG. 7. Two ring-parts I6 and 17 are fuse-bonded together as by soldering with a soldering paste matching the metal of the ring. The joint between the two ring-parts should be completely undetectable. at least to the naked eye.  
 METI-IOD OF MANUFACTURE The basic concepts of a suitable method of manufacture are illustrated in the drawings. As illustrated in FIG. 1, grooves are cut into the outer peripheral surface of the inner ring-part 16. Although this is illustrated as being performed on a lathe with one groove cut at a time into a separate ring-part 16, a screw machine will usually be used. In that instance the grooves may be cut all at once and before the ring-part 16 is severed from the tube being fed into the screw machine.  
  FIG. 2 diagrammatically illustrates the application of a soldering paste to the inner surface of the outer ringpart 17. According to present practice. a small amount of the paste is smeared to thinly coat the entire inner surface of the ring-part 17. A possible alternative is to apply the paste by a set of printing rollers to the faces of the ribs 13, much as printer&#39;s ink is applied to the raised typein letterpress printing. The soldering paste should of course be one which matches the metal of the ring. Thus if the ring-part 17 is of l4-carat gold. a 14- carat gold solder should be used.  
  The outside diameter of ring-part 16 is slightly less than the inside diameter of ring-part I7, so that when the ring-part 16 is slid into the ring-part 17., a sufficient coating of the soldering paste will be expected to remain at all points. But turning one part within the other something like a quarter turn will tend to respread the solder coating in case any spot has been scraped clean.  
  The next step is to tighten the contact between the inner and outer ring-parts. One way to do this is illustrated in FIG. 3. With the loosely assembled ring positioned loosely in a fixture 21. an enlarging plunger 22 is driven through the inner ring-part I6. stretching it beyond its elastic limit so that at its new size. it fits tightly within the outer ring-part 17. The present practice is to accumulate a number of tightened ring assemblies on the press rod 24 and then remove the enlarging die 22 to remove the tightened rings.  
  Another method of providing a tightened ring assembly would be to make the ring-parts 16 and 17 such that at the same temperature they have tight engagement. but achieve looseness during the initial assembly by a temporary but substantial temperature differential between the two parts. either heating the outer ring-part 17 or chilling the inner ring-part 16.  
  The next step is to heat the tightened ring assembly to fuse the solder between the ring-parts. thereby fusebonding the two ring-parts together. With a tight fit between the parts indicated by FIG. 3, excellent fusebonding is achieved. If there should be any contacting areas deficient in solder. the solder tends to be drawn throughout such areas by capillary action.  
  The next step is to trim the edges of the ring as is diagrammatically illustrated in FIG. 5. Present practice is to trim off approximately 0.005 inch from each edge. This usually makes the fused joint imperceptible. at least to the naked eye.  
  Of course. the ring is subjected to the usual final polishing. Also any desired decorative treatment may be given.  
 ACHIEVEMENT In the use of the present invention. it is easy to save on the order of 25 percent of the precious metal. even though the ring has the same external appearance as if it were solid. and the same stretchability to enlarge its size. Virtually I00 percent of the precious metal cut from the ring-parts in forming the grooves and in trimming the edges is salvaged and reprocessed.  
 FURTHER VARIATIONS AND DATA Dimensions which will give adequately reinforcement during stretching and yield the desired or maximum saving of precious metal can be determined by test. Present manufacturing practice. stated in inches. is to have grooves 0.020 deep (at center of concave base of groove) by up to 0.0375 wide. with a rib thickness of 0.0 l 35. The end grooves are at least 0.030 from the edges. even if this reduces the width of these end grooves.  
  In theory. the two ring-parts can be initially tight fitting. and can even have a press lit. The mating surfaces can be machined. if necessary for sufficient accuracy. Satisfactory fuse-bonding. at least at the edges. would still be desirable. If tests of applying soldering paste at the edges to be drawn into the edge area during heating do not show satisfactory results. some other method of fuse-bonding could presumably be worked out. Fusebonding at the inner ribs is not believed to be essential. though it is at present provided.  
  The grooves can theoretically be formed by rolling. Outer dimensions would change. but with experience allowance could be made for this. The ribs could be tapered. thicker at their bases. and this would be desirable in the event of formation by rolling.  
  The grooves could be formed on the inner surfaces of the outer ring. but the illustrated location is preferred. Not only is it easier to produce. but also a given supply of grooved inner ring-parts of one form can be used for a variety of different outer ring-parts.  
 I claim:  
  I. A precious-metal ring having concealed within its body. for saving metal while retaining good stretchability characteristics. narrow steep-sided enclosed annular voids separated by annular rib means. the rib means reinforcing the ring against collapsing when stretching it to enlarge its size by providing. with annular continuity. metal from outer to inner faces of the ring.  
 2. A precious-metal ring having concealed within its body. for saving metal while retaining good stretchability characteristics. narrow steep-sided annular grooves separated by annular rib means. the rib means reinforcing the ring against collapsing when stretching it to enlarge its size by providing. with annular continuity. metal from outer to inner faces of the ring:  
 said ring comprising inner and outer ring-parts with the grooves and rib means formed in one of these parts and the rib means bearing on the other of these parts to form enclosed voids.  
  3. A preciousmetal ring having an inner annular ring part and an outer annular ring part. said ring having concealed within its body a plurality of enclosed annular voids for saving a substantial proportion of precious metal. and radially extending means of annular rib form for allowing said ring to be stretched satisfactorily in the manner of stretching a solid ring. said voids being formed from grooves bounded by the sides of said annular ribs on one of said parts and a mating surface on the other of said parts. said ribs and surface being bonded together. said ribs reinforcing the ring against collapsing when stretching it to enlarge its size.  
  4. A precious-metal ring having concealed within its body. for saving metal while retaining good stretchability characteristics. narrow steep-sided annular grooves separated by annular rib means. the rib means reinforcing the ring against collapsing when stretching it to enlarge its size by providing. with annular continuity. metal from outer to inner faces of the ring;  
 said ring comprising inner and outer ring-parts engaging one another firmly at their mating surfaces and with mating surfaces fuse-bonded together. with the grooves and rib means formed in one of these parts and the rib means bearing on the other of these parts to form enclosed voids.