Patent Publication Number: US-6217314-B1

Title: Disposable, recyclable oil candle

Description:
This application claims the benefit of U.S. Provisional Application No. 60/133,780, filed on May 12, 1999, which provisional application is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     Design and manufacture of oil candles. 
     BACKGROUND OF THE INVENTION 
     Oil candles are commonly used for clergy purposes, but have also been widely used for restaurant, florist, wedding, or other purposes. 
     For many reasons, consumers prefer to use oil candles instead of conventional beeswax candles. First, beeswax candles melt when used; therefore, the longer the candle is in use, the shorter it becomes. Aesthetically, it is often undesirable to have candles that vary in length. In addition, beeswax candles have a tendency to drip during use, leading to wax build-up that requires clean-up. Finally beeswax candles are susceptible to the elements; for instance, wind can adversely affect a candle&#39;s performance. 
     Oil candles, while preferred to conventional beeswax candles, also suffer from disadvantages. For instance, oil candles require refueling. In many early model oil candles and some modern candles, users must disassemble the candle and add oil to refuel it. Many consumers find refueling to be cumbersome and inconvenient. In an effort to reduce the time and effort spent refueling oil candles, manufacturers developed oil candles with disposable fuel cells. A disposable fuel cell enables the user to refuel an expended oil candle by simply removing the empty cell and replacing it with a new one. Although, disposable fuel cells have made refueling easier, there are other disadvantages to be considered. 
     For instance, many conventional oil candles include a disposable fuel cell or bottle and a reusable shell. Manufacturers often make the reusable shell of glass, metal, or a fire-resistant plastic so that the shell does not melt. Moreover, to retain the look of a conventional beeswax candle, manufacturers often produce exterior shells having the same shape and color of ordinary beeswax candles. Unfortunately, reusable shells of this kind are quite costly. Furthermore, in addition to the high cost of the exterior shell, many consumers find it inconvenient to have to continuously remove and replace empty fuel cells. 
     Conventional oil candles can also be unsafe. Generally, a disposable fuel cell is inserted into the candle and is left unsecured so that it can be easily removed from the exterior shell. While this allows users to have easy access to remove and replace an empty cell, it also provides others with the same opportunity. The removal of the fuel cell from the candle can pose a serious safety hazard. Individuals who want to vandalize a candle or simply remove a fuel cell to save an insignificant amount of money by refilling an empty cell instead of replacing it with a new one are free to do so. Many conventional oil candles do not include safety features to deter the removal of the fuel cell. 
     Yet another disadvantage associated with ordinary oil candles is the lack of versatility. Since there is no universal size for candle holders, no single oil candle can satisfy the needs of all consumers. For instance, most candle holders are either two inch, one and one-half inch, seven-eighths of an inch, one and one-eighth of an inch, or “all purpose end” sized holders. Therefore, manufacturers must produce many different sized oil candles to satisfy the needs of their consumers. Furthermore, consumers are burdened by having to check the size of their holder to make sure that the candles they order are the correct size. 
     We have developed an oil candle that is not only superior to conventional beeswax candles, but is also cheaper to manufacture, less expensive to ship, easier to use, safer, and more versatile than existing oil candles. 
     SUMMARY OF THE INVENTION 
     Our oil candle is fully disposable. Instead of a reusable glass, metal, or thick fire-resistant plastic exterior shell, we prefer to use a thin, blow-molded resin shell. The use of a thin, resin shell greatly reduces the overall cost of each candle. By blow molding the exterior shell, we can produce a shell that uses less material and is therefore less expensive than the thicker, reusable resin shells commonly used in ordinary oil candles. Furthermore, by making the shell sufficiently inexpensive, it becomes more economical to discard the entire candle than it is to refuel the candle and reuse the exterior shell. 
     While our candle is less expensive than existing oil candles, it is also more convenient. Instead of having to take the time to disassemble the candle to remove and replace an empty fuel cell, our model allows the user to simply discard the empty candle and replace it will a new fully fueled unit. Moreover, since our candle is designed to be recycled, it poses no risk to the environment. 
     Until now, manufacturers have not offered consumers a fully disposable oil candle. To produce an oil candle that is fully disposable, a manufacturer must develop a disposable exterior shell that preferably has the appearance of a conventional beeswax candle and is inexpensive enough for single use but also sufficiently resistant to heat to prevent it from melting. The fuel cells used in oil candles include a metal cap to center the wick. When lit, the metal cap becomes heated by the flame of the candle. Conventional oil candles include exterior shells made of metal, glass, or fireresistant plastic to withstand the heat generated by the metal cap. However, our blow-molded exterior shell does not offer the same thermal resistance. Therefore, we have designed our oil candle to include a separator that is preferably molded as part of the fuel cell to maintain a minimum insulating distance between the fuel cell and the outer shell to prevent the outer shell from melting. 
     In addition to functioning as a thermal insulator, the separator can also function as a safety device. We configure the separator to allow a user to insert the fuel cell into the exterior shell so that the cell and exterior shell become permanently joined. By joining the cell and the exterior shell, the candle becomes a single inseparable unit. Once joined, the fuel cell becomes extremely difficult to remove, thereby effectively minimizing potential safety hazards associated with the removal of the fuel cell. 
     Finally, we prefer to include a uniquely shaped base on our oil candle to improve the candle&#39;s versatility. Because there are so many different sized candle holders, no single candle can satisfy the needs of every consumer. Therefore, we provide two models of our candle with unique bases to alleviate this problem. By tapering the base of each candle and supplying an optional sleeve, we can offer consumers an oil candle that fits almost every standard-sized candle holder on the market. This minimizes the need to custom-manufacture candles to meet consumer needs. 
     Our oil candle is an improved alternative to conventional beeswax candles and ordinary refillable oil candles. Our candle is more economical, more convenient, more protected, and more versatile than other oil candles on the market. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1A is a schematic view of a metal wick cap. 
     FIG. 1B is a schematic view of a disposable oil fuel cell. 
     FIG. 2 is a schematic view of a blow-molded disposable shell. 
     FIG. 3 is a schematic view of the assembled oil bottle. 
     FIG. 4 is a partial cut-away view of the assembled candle. 
     FIG. 5A is a schematic view of one embodiment of a base of the oil candle. 
     FIG. 5B is a schematic view of a second embodiment of a base of the oil candle. 
     FIG. 6 is a partial cut-away view of an alternate embodiment of the assembled candle. 
    
    
     DETAILED DESCRIPTION 
     Our disposable oil candle  20  is comprised of a disposable, blow-molded, resin exterior shell  15  and a disposable oil-filled fuel cell  10 . 
     The disposable blow-molded exterior shell  15  is made of a resin that is preferably lightweight and relatively inexpensive; PVC is one suitable resin. The resin shell  15  is treated with a fire-retardant so that it cannot support a flame. In addition, we prefer to select a resin that is also recyclable so that the disposal of the shell does not pose an environmental risk. Furthermore, we also prefer to configure the shape and adjust the color of the shell  15  so that it resembles a conventional beeswax candle. A radial groove  6  formed along the interior side wall of the shell  15  at the shell&#39;s opening accepts an inserted fuel cell and holds it firmly in place. The base  7  of the shell  15  is preferably tapered and configured to include longitudinal ridges  8  so that the shell  15  can be firmly inserted into a holder (not shown). 
     The disposable fuel cell  10  is also blow molded from a resin. Again, we prefer to use a resin that is relatively lightweight and inexpensive so that the cost of disposal is minimized. Also, the resin selected should be recyclable to minimize the environmental impact of disposal. In addition, because the cell  10  will be exposed to flame, we prefer to treat the resin with a fire-retardant so that the resin will not support a flame. Moreover, because of the heat generated during use, the fuel cell  10  should be configured to include a thick upper rim  3  along the circumference of the open end of the cell  10  to prevent the cell  10  from melting. The ring  3  along the circumference of the open end of the cell  10  is also formed to support a metal wick cap  5 . The wick cap  5  includes a radial base ring  1  that is slightly larger in diameter than the support ring  3  at the open end of the cell  10 . The base ring  1  fits comfortably over the support ring  3  to close the open end of the cell. The manufacturer can then secure the metal cap  5  to the cell  10  by mechanically wedging the cap  5  onto the supporting ring  3 , thereby sealing the cell  10  so that the oil (not shown) within it does not escape during shipping. Finally, we prefer to include a separator as part of the fuel cell to maintain a minimum insulating distance from the metal wick cap  5  to the exterior shell  15 . The insulating distance can be a minimum vertical or lateral distance, or it can be both a vertical and horizontal distance. More specifically, we prefer to mold the fuel cell  10  to include a snap ring  4  that can be snapped into the radial groove  6  of the shell  15 . (An alternative embodiment where a snap ring  4  is included in shell  15  and a radial groove  6  is included in fuel cell  10  is illustrated in FIG.  6 .). By snapping the fuel cell  10  into place, the fuel cell  10  becomes permanently joined with the shell  15 . The snap ring  4  holds the fuel cell  10  in place, ensuring that the heated metal cap  5  remains at a minimum insulating distance from the exterior shell  15  to prevent it from melting. Although, we prefer to use a snap ring  4 , other alternative separating structures can be used to maintain a minimum distance between the metal cap  5  and the shell  15 . However, the snap ring  4  is ideal because it maintains the requisite minimum distance between the cap  5  and the shell  15  while keeping the cap  5  nearly flush with the opening of the shell  15  so that the candle  20  can maintain the appearance of an ordinary beeswax candle. Other separating structures can provide the desired space between the cap  5  and the shell  15 , but can alter the candle&#39;s appearance, making it appear less like a beeswax candle. 
     In addition to functioning as a thermal insulating structure, the snap ring  4  can also function as a safety feature. Because of potential safety hazards associated with the removal of a fuel cell from an oil candle, we prefer to configure the snap ring  4  so that once the fuel cell  10  is inserted into the shell  15 , the snap ring  4  enters the interior radial groove  6  and permanently joins the cell  10  and exterior shell  15  (see FIG.  4 ). By joining the cell  10  and the exterior shell  15  in this manner, it becomes extremely difficult to remove the cell  5  from the exterior shell  15  and effectively minimizes safety hazards that may otherwise exist. 
     Finally, our candle  20  also includes a uniquely shaped base to improve versatility. Because there is no single standard-sized candle holder, manufacturers and consumers are required to produce or purchase oil candles that are custom-made to fit a given holder. This requires consumers to take the time to order the correct size candle and requires manufacturers to produce several different sized candles to meet the demands of consumers. We produce at least two models of our candle  20  with bases configured to fit virtually all standard-sized candle holders currently on the market. The first model, as shown in FIG. 5A, includes a tapered base  7 . By itself, this base is capable of being used with any seven-eighths inch holder. In addition, we include a sleeve  13  with this model so that the candle can also fit in a one and one-eighths inch holder, which is the standard size holder for the Protestant religions. We also produce a second model with a tiered base, as shown in FIG.  5 B. This base includes a first tier  9  that is slightly narrower than the circumference of the shell  15  and a second tier  11  that is narrower than the first tier  9 . This unit can be inserted using the first tier  9  in any one and one-half inch holder. Alternatively, a sleeve  12  can be used with this model to allow the candle to fit any two inch candle holder. In addition, this unit can also be inserted into any “all purpose end holder” using the second tier  11  in conjunction with the sleeve  12  to provide added stability. By configuring our candle  20  to include one of these two bases, our candle  20  can be used with 90% or more of the standard-sized candle holders currently in use. This allows manufacturers to be able to fashion a candle that is virtually a one-size-fits-all product. 
     Our disposable oil candle  20  offers several advantages that are not available to consumers who own conventional oil candles. For instance, unlike existing models, our candle  20  does not require refueling. When the candle  20  runs out of oil, the user can simply remove and discard it and then replace it with a new unit. Consumers will enjoy the added convenience of this feature. Furthermore, since we produce our candle  20  from recyclable resins, its disposal does not pose a threat to the environment. 
     In addition to being more convenient than existing oil candles, our candle  20  is also more economical. Because we use a thin blow-molded resin shell  15 , our shell  15  requires less resin than conventional oil candles that use thicker resin exterior shells. Furthermore, since our shell  15  is kept at a minimum insulating distance from the heated metal cap  5  of the fuel cell  10  to prevent melting, the resin used to form the shell  15  does not have to be as robust as resins used in conventional oil candle shells; therefore, we can use less expensive resins. An even greater economic advantage is realized when comparing our blow-molded resin shell  15  with the more expensive glass or metal exterior shells used in conventional oil candles. 
     Not only is our disposable candle  20  more economical to manufacture than conventional oil candles, but our candle  20  with its thin, blow-molded disposable shell  15  is also lighter than existing oil candles. The weight of the finished product is significant because of the effect of the product weight on the cost of shipping and distribution. By making the shell  15  thinner and therefore lighter, our candle  20  can be shipped to consumers at a fraction of the cost of conventional oil candles of comparable size. 
     Our candle  20  is also safer than conventional oil candles. The snap ring  4  permanently joins the fuel cell  10  and exterior shell  15 , making it extremely difficult to remove the cell  10 . By joining the fuel cell  10  and exterior shell  15 , our unit  20  can prevent individuals from removing the cell  10  and can effectively minimize the likelihood of injury or damage. 
     Finally, our candle  20  is more versatile than conventional oil candles. By configuring our candle  20  to include one of the two above-described bases, our candle  20  can be manufactured and sold to fit 90% or more of the standard-sized candle holders currently in use. 
     Our candle  20  is an improved alternative to existing oil candles since it is less expensive to manufacture and ship, easier to use, and safer and more versatile than conventional oil candles.