Abstract:
An oil lamp emitting a fragrance has a container including a fuel oil and a fragrance and a wick for drawing fuel oil out of the container for burning. A separate ceramic diffuser is positioned adjacent the top of the lamp, near the combustion end of the wick. The ceramic diffuser receives a combination of fuel oil and fragrance and diffuses the fragrance into the air. The diffusion is increased when the lamp is lighted. The lamp provides a scent to the surrounding air which is similar in strength to fragranced wax candles.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates generally to the field of oil lamps and in particular to a new and useful oil lamp having a porous diffuser for imparting a fragrance into the air from the oil lamp. 
     Many different types of oil-burning lamps are known. Some lamps incorporate a fragrance into the fuel oil, while others provide for a separate fragrant emitting portion, or emanator. 
     U.S. Pat. No. 5,840,246, for example, is for an oil lamp having a porous emanator supported on the neck of a container holding a flammable liquid, such as oil. A wick holder passes through the center of the emanator and supports a wick therein. The wick is in contact with the oil and draws oil up above the emanator for combustion. The emanator is impregnated with a fragrance, which is released into the air, especially when the wick is lit. 
     The wick holder in U.S. Pat. No. 5,840,246 is not used to draw oil and fragrance from the flammable liquid up to the emanator; the holder is an optional component for supporting the wick. 
     The oil lamp claimed by U.S. Pat. No. 4,892,711 has a canister holding the fuel oil, a burner assembly supported on the canister, and a fragrance element spaced from the burner assembly. In a preferred embodiment, the fragrance dispensing element is “ring-like” and it is “mounted on said canister and surrounding said burner assembly”. Only the fragrance element contains a fragrance in the oil lamp of U.S. Pat. No. 4,892,711, and the element does not contact the wick. 
     A leak-proof lamp is shown in U.S. Pat. No. 5,000,678 which has an inner flange having substantially the same frusto-conical shape as the outer covering that is fit over the opening of the fuel oil container. The inner flange extends into the opening of the container and seals against the inner wall of the container opening. The outer covering has a bottom edge which is secured around a horizontal lip on the container opening. The inner flange is secured to the outer covering by spot welding, or they can be formed integral. 
     Other lamps include U.S. Pat. No. 5,891,400 for a heat-activated volatile substance dispenser. The dispenser has two containers, an inner container holding a heat source, such as a candle and an outer container surrounding the inner container forming an annulus holding a gel incorporating the volatile substance. The inner container has an open top and holds a burnable material, such as a candle. The combustion of the candle in the inner container causes the gel in the annulus to release fragrance when heated by the walls of the inner container. 
     Other patents disclose oil lamps having drip collars around the neck, such as U.S. Pat. No. 40,094. The body of the lamp vessel is generally cylindrical with rounded sides and a neck opening at the top. An annular depression is formed around the neck opening to catch dripping oil and prevent it from falling outside the lamp body. There is no fragrance emitting portion on this lamp. 
     A fuel supply vessel for an oil burning incubator lamp has a centrally located raised neck for supporting the lamp and holding the wick in position to deliver fuel to the lamp from the vessel is taught by U.S. Pat. No. 871,016. The fuel supply vessel has a raised outer edge as well, to form a reservoir pan around the raised neck on top of the vessel. The reservoir is filled with water to dissipate heat from the burning lamp wick. 
     U.S. Pat. No. 3,790,332 shows a oil lamp candle having a wick holder which floats on the fuel oil in a container, such as a glass. The wick holder is a cylindrical boat with a raised central portion supporting the wick above the outer edge of the boat, and forming an annular space inside the boat. The annular space is not disclosed as being filled by any substance and is left open. 
     U.S. Pat. No. 3,958,917 teaches a scented ring for use with candles made of a wax-like material impregnated with a fragrant composition. The ring is positioned around the wick of a wax candle and is consumed by use, while releasing fragrance. 
     An oil lamp for diffusing fragrance contained in the oil is disclosed in U.S. Pat. No. 5,669,767. The lamp has a metal tube wick holder supported by a perforated cone in the neck of the lamp vessel. The burning wick heats the tube, which in turn heats the oil, causing it to release fragrance into the air through the perforations in the cone. 
     A primary difficulty experienced by many prior art oil lamps which emit a fragrance is to provide a sufficient amount of fragrance from the lamp. This problem is apparent especially when the fragrance is combined in the oil being burned. The intent of these lamps is that the oil and fragrance will both drawn up the wick and fragrance will be released. However, typically, both the fuel oil and fragrance oil are burned, generating either only a “fuel” smell, or a burnt smell from combustion of the fragrance. 
     Lamps which have separate fragrance emanators suffer from the difficulty of ensuring the fragrance is released at a sufficiently high rate so that the fragrance is smelled over the burning of the fuel oil. It is common to use the heat of the flame burning fuel oil to warm a separate emanator, usually by placing them in proximity to each other, to enhance the release rate of fragrance from the emanator. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an oil lamp which emits a strong fragrance, especially when lighted. 
     It is a further objection of the invention to provide an oil lamp which includes protection from spills and leaks. 
     Yet another object of the invention is to provide an oil lamp having a diffuser for fragrance oil combined with the fuel oil. 
     Accordingly, an oil lamp is provided having a container with a top opening, a ceramic diffuser mounted in the top opening, a sealing gasket between the top opening and ceramic diffuser, a wick holder covering the ceramic diffuser and secured to the top opening, and a wick passing through the ceramic diffuser and one end extending above the wick holder. The other end of the wick extends into a mixture of fuel oil and fragrance in the container. Fragrance and fuel oil are both drawn up the wick. Some oil is absorbed by the ceramic diffuser and diffused into the air surrounding the oil lamp. Other fuel oil and fragrance are burned at the top end of the wick above the wick holder. 
     The oil lamp contains a mixture of fuel oil and about 3-5% wt. of perfume. The intensity of the perfume is sufficient to mask the smell of burning fuel oil and perfume and provides a scent which is at least as intense as perfumed wax candles. 
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a top, front, side perspective view of an oil lamp according to the invention; 
     FIG. 2 is a is a sectional side elevational view of the oil lamp of FIG. 1; 
     FIG. 3 is an exploded top, front, side perspective view of the components of the oil lamp of FIG. 1; 
     FIG. 4 is an enlarged sectional side elevation of the top portion of the oil lamp of FIG. 2; 
     FIG. 5 is a top, front, side perspective view of a diffuser of the invention used in the oil lamp of FIG. 1; 
     FIG. 6 is a sectional side elevational view of an alternate embodiment of the diffuser according to the invention; and 
     FIG. 7 is a further embodiment of the oil lamp having a lampshade. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows an oil lamp  5  having a container  10  for holding fuel oil and a perfume, an outer cover  40  and a fiber wick  50 . The outer cover  40  protects the fragrance diffusing portion of the lamp  5  and helps to seal the top opening of the container  10 . The container  10  can be any known shape which provides a decorative look and will stand substantially upright so that a flame on wick  50  can burn without disruption. A container shape having a reduced cross-sectional area at the bottom is preferred so that less fuel is wasted due to lack of access to the wick  50 . 
     FIGS. 2 and 3 show the components of the lamp underneath the outer cover  40 . 
     FIG. 2 displays the internal portions of the oil lamp  5 , including ceramic diffuser  30 , the top opening  12  of container  10  having inner wall  18  and fuel oil and fragrance mixture  100  in the container  10 . Fuel oil and fragrance mixture  100  is drawn up fiber wick  50  into contact with ceramic diffuser  30  for diffusing the fragrance into the air. The wick  50  has a top end  60  which extends through wick holder  55  on the outer cover  40 . In a preferred embodiment, the wick  50  is doubled over forming a loop at top end  60 . Such a construction assists manufacture of the oil lamp  5 . The top end  60  receives fuel oil and fragrance mixture  100  and can be lighted to burn fuel oil from the mixture  100 . 
     As best seen in the exploded view of FIG. 3, the outer cover  40  has several vents  45  through the sides. The vents  45  are provided for permitting fragrance drawn through the wick  50 —shown as a single strand embodiment in FIG.  3 —and absorbed by the ceramic diffuser  30  to be emanated by diffusion into the air surrounding the lamp  5 . Different numbers and sizes of vents  45  may be used, provided the structural integrity of the outer covering  40  is maintained. 
     A sealing gasket  20  is interposed between the lower surface of the ceramic diffuser  30  and the upper surface  16  of top opening lip  15  on container  10 . The outer cover  40  fits over the ceramic diffuser  30  and secures it in place on the sealing gasket  20  to provide a seal between the diffuser  30  and container top opening  12 . It is intended that the fuel oil and fragrance mixture  100  can only exit the container  10  via the wick  50  or by diffusion through ceramic diffuser  30 , as described in greater detail below. 
     FIG. 4 shows the upper portion of the lamp  5  in greater detail, so that the seal provided around the upper surface  16  of the top opening  12  is more clearly seen. The sealing gasket  20  fits between the upper surface  16  and the lower edge of the diffuser  30 . The lower edge is formed as a flange surface  33  with an adjacent vertical wall  32 . The flange surface  33  contacts the sealing gasket and provides the sealing surface with the upper surface  16 . The vertical wall  32  is used to help position the ceramic diffuser  30  over the top opening  12 . The vertical wall  32  may contact top opening wall  18  to further improve the seal as well. 
     The outer cover  40  fits over the ceramic diffuser  30  and has an inwardly turned bottom edge  42  which fits over top opening lip  15 . The bottom edge  42  is formed by crimping. Pressure from the top of the outer cover  40  adjacent the wick holder  55  holds the ceramic diffuser  30  against sealing gasket  20  and upper surface  16 , forming a substantially leak-proof seal. The seal is intended to prevent large volume spills through the vent holes  45  when the oil lamp  5  is tipped over by accident. 
     Spills of the mixture  100  are substantially prevented since the wick  50  preferably occupies a majority of the space in wick passage  35  of the ceramic diffuser  30 . Small amounts of mixture  100  may escape through gaps between the wick  50  and wick holder  55  opening or air vent  56 . The wick  50  occupies substantially the entire wick holder  55  opening in order to be held in position properly. The greater the contact made between the wick  50  and walls of wick passage  35 , the greater the amount of fragrance that will be emanated from the ceramic diffuser  30  as well. 
     FIG. 5 displays the ceramic diffuser  30  so that the exterior shape can be seen. The shape is preferably similar to the contours of the outer cover  40  so that the maximum surface area and volume for the diffuser  30  are obtained. It should be noted that while the wick passage  35  is shown through the center of the diffuser  30 , it may be placed off-center, provided the wick  50  can still be positioned through a wick holder  55  in the outer cover  40 . The wick holder  55  may be placed off-center in such case as well. Further, the wick holder  55  and diffuser  30  can be non-circular. 
     An alternate shape of the ceramic diffuser  30  is shown in FIG. 6 which has an extended portion, or tail  130 . The tail  130  is sufficiently long to extend into the fuel oil and fragrance mixture  100 , so that oil and fragrance are directly absorbed by the diffuser  30 . The wick passage through the diffuser  30  is extended through the tail  130  to provide access for the wick  55  to the mixture  100 . 
     In a further embodiment, a non-combustible lampshade  200  may be positioned over the oil lamp  5  and supported on the top edge  48  of the outer cover  40 , as shown in FIG.  7 . 
     Preferred materials for the components of the oil lamp  5  include plastics, such as thermoplastics, metal, glass and ceramic for the container  10 , although durable plastics are most preferred. PVC is preferred for a clear plastic container. The ceramic diffuser  30  is preferably made of an alumina bisque, but other porous ceramics and materials such as POREX foam and cellulose are acceptable for use as well. 
     Mercury porosimetry and nitrogen adsorption measurements of alumina bisque pore size and pore volume indicate acceptable diffuser ranges have pore sizes of about 0.5 to 2.0 microns and pore volumes of about 0.15 ml/g to 0.30 ml/g. The optimum size and volume of the reticulated pores depends upon the hydrophobic character of the diffuser and the fragrance/oil mixture. For example, a hydrophobic diffuser and a hydrophobic fragrance/oil mixture can accommodate larger pore size and volume for mass transport through the diffuser. A more hydrophilic diffuser, such as cellulose, requires a smaller pore size and volume to maximize capillary action for mass transport. One skilled in the art will understand that the addition of combustible, oil soluble surface-active materials to the lamp oil can be used to optimize various diffuser and fragrance/oil combinations. 
     The diffuser can be shaped differently to further increase the diffusion surface area, such as by including fins or other surface texture, provided it does not interfere with the outer cover  40 . 
     The outer cover  40  is preferably made entirely of metal or other non-combustible, heat-conducting materials, since the flame of the lamp is in close proximity to the top of the cover  40 . The heat transfer properties of the material used should be selected to heat the ceramic diffuser to enhance evaporation of fragrance or fuel plus fragrant oil from the saturated diffuser body, but also to limit the heat transfer to the diffuser to about 50° F. less than the flashpoint of the fuel and fragrance mixture  100 , or less than about 175° F. 
     The enhanced evaporation of the fragrance causes more liquid mixture  100  from the oil lamp container  10  to be absorbed into the diffuser, to replace the liquid that had evaporated due to the extra heating of the diffuser. 
     Bendable metals such as tin which are easily crimped over to form the bent lower edge  42  are preferred for use for the outer cover  40 . The outer cover  40  may also have a plastic lining of a non-combusting material to improve the seal between the outer cover  40  and diffuser  40 . 
     The fuel oil can be any known type used in oil lamps, but paraffin lamp oil is preferred. The fragrance is preferably present in the mixture in an amount between 3-7% wt. of the total mixture, with about 5% being most preferred. Perfumes and other fragrance oils can be used for the fragrance. 
     In use, the lamp  5  is lighted, and heat from the flame at the top end  60  of fiber wick  50  heats the metal outer cover  40 . Heat is transferred to the ceramic diffuser  30 , which has received oil and fragrance mixture  100  from the wick  50  passing through wick passage  35 . The heat causes more of the fragrance absorbed by the ceramic diffuser  30  to evaporate and diffuse into the air through the vents  45  in the outer cover  40 . 
     In the event that the lamp  5  is tipped over, the sealing gasket  20  and wick  50  prevent large amounts of oil from leaking out of the lamp  5 . At the same time, the ceramic diffuser  30  directly absorbs more of the mixture  100  due to contact from tipping. The ceramic diffuser  30  becomes saturated, but will not drip and provides a seal for the container  10 . This permits the oil lamp  5  to be safely shipped in an assembled state. 
     The lamp  5  of the invention improves over prior disposable lamps which have separate fragranced emanators since the oil and fragrance are used up at the same rate. Further, when preferred materials are used, testing has shown that the lamp  5  of the invention can provide a fragrance to an area having substantially the same effect as commercially available 3″×3″ pillar-type candles. 
     The oil lamp  5  provides a self-contained, spill proof lamp which can be manufactured in many different fragrances simply by changing the fragrance added to the oil mixture, rather than having to substitute different emanators or scent packets or supplies. 
     While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.