Abstract:
A lamp dispenses a volatile material, such as an insecticide, from a burnable coil. There is a flame source mounted on a base, a chimney, a coil support, and a burnable coil supported on the coil support above the flame. The flame provides light, heats the coil to some extent, and provides convection for dispersal of the volatile. A kit for replacing the candle and coil consumed during use is also disclosed, as are methods of use of such lamps.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     This invention relates to dispensers for volatile materials such as insect control agents, scents and the like. In particular, the invention relates to dispensers that simultaneously dispense a volatile from a burnable coil and provide illumination. 
     There are a number of known dispensers for volatile ingredients that provide the additional feature of lighting the surrounding area. For example, U.S. Pat. No. 6,033,212 discloses a lantern that burns fuel for light. The flame is contained in a glass, transparent globe that is covered at its top. The cover has a slot that receives a pad impregnated with a volatile material having an insect control agent. The waste heat from the burning fuel exits the globe through the slot, which heats the pad and releases the volatile. 
     WO 00/78135 is another approach for mounting an insect repellent impregnated pad adjacent a flame. However, the types of pads used with these designs can be somewhat costly to produce, and in some cases place constraints on the type of active that can be used. 
     Citronella candles also provide both light and an insect repellent, and do so relatively inexpensively. However, exposed candle flames can be snuffed by the wind, and not all actives can survive being directly exposed to the candle flame when the candle wax is burnt. 
     Insect (e.g. mosquito) coils are also well known. They are typically a spiral coil of compressed, largely pulp material which has been impregnated with an insect control active. The coils can alternatively (or in addition) contain other active ingredients having different characteristics, such as aromatics or disinfectants. These coils are extremely inexpensive, and due to their slow burn rate provide overnight protection. They are particularly desirable because of their ability to disperse a variety of very effective insecticidal actives, at low cost. 
     However, these coils can be snuffed out if they are exposed to too much wind. Thus, it has been proposed to house them in apertured pots that can prevent outside gusts from directly reaching the coil. See e.g. U.S. Pat. No. 6,061,950. These pots also have the benefit of inhibiting persons from accidently bumping into these coils while they are burning. However, these pots dispense active at a slower rate than a coil that is directly open to the air, thus requiring them to be started somewhat earlier before using an area that might be insect infested. 
     Some other structures have been proposed to dispense insecticidal control agents by mounting materials containing them adjacent a heat source. See e.g. U.S. Pat. Nos. 692,075, 2,742,342 and 3,279,118. However, to date the art has not proposed a way to mount a mosquito coil in a lamp in a way in which the lamp flame assists in the dispersion of the vapors from the coil, without causing the entire coil to start burning out of sequence. Thus, there is still a need for an improved combined lamp and volatile dispensing device. 
     SUMMARY OF THE INVENTION 
     In one aspect the invention provides a lamp for dispensing a volatile material. There is a flame source, a chimney mounted around the flame source, a support mounted to the chimney above the flame source, and a burnable coil having a volatile material. The coil is positioned above the flame source so as to be exposed to heat therefrom. 
     In preferred forms the support is a plate having an opening (preferably a plurality of openings) there through. The support may also have a raised element (a spade) for supporting the coil, with the coil being mounted adjacent an upper opening of the chimney, vertically above the flame source. The chimney can have a radially inwardly extending ledge on which the support rests. 
     There is also preferably a skirt-like base upon which the flame source and chimney are mounted, an upper surface of the base having a recess for receiving a lower edge of the chimney. The base includes a plurality of openings positioned radially outside of the recess and a plurality of openings positioned radially inward of a radially outer edge of the recess. Air may pass inward through the radially outside openings, and then up through the chimney via the radially inward openings. 
     In other preferred forms, the recess includes a central depression for receiving the flame source, the flame source is a cup containing a candle, and the cup has a bottom with a recess sized to receive an upwardly extending mounting post of the cover. The support can optionally have a collector tray suspended below a top wall opening of the support so as to collect ashes, and/or the support top wall can include a recessed central section having no vertical openings there through, and a radially outward section having an opening there through. 
     The additional heat which builds up due to air flow through outer peripheral openings can be taken advantage of. There can be a faster release of active near the outside of the coil (as that portion is exposed to more heat). This enables an area to be adequately treated very soon after the device is lit. If desired, this effect can be enhanced by providing a higher concentration of active (per unit mass) near the outer periphery, and/or two different types of active (the more potent being on the outer periphery). 
     In another aspect, the invention provides a kit providing a replacement coil and candle for lamps of the above kind. A cup for housing the candle (e.g. one which interfits with the base) may also be supplied with the kit. 
     Still another aspect of the invention provides a method for controlling flying insects. One provides a lamp of the above kind, lights the coil and the flame source, and permits volatizable material to pass from the coil and out the chimney so as to expose an area to the volatizable material. The volatizable material is an insect control agent. 
     Preferred insect control agents are insecticides, repellents, and insect growth regulators. A wide variety of insect control agents of this type are known. The preferred ones are those which have previously been incorporated into mosquito coils, such as d-cis/trans allethrin. 
     Because the lamp provides both light and insect control, and does so even in windy environments, it is particularly suitable for use during a backyard barbecue, around sunset. The device is designed to utilize extremely inexpensive consumables (e.g. standard conventional burnable coils; standard wax candles). 
     The flame source serves multiple purposes. It provides light, while also creating convection to draw outside air past the burning coil. The air/volatile mix is then propelled out the top of the chimney to widely and quickly disperse the active. 
     The foregoing and other advantages of the present invention will appear from the following description. In that description, reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Rather, reference should be made to the claims for interpreting the full scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cut-away perspective view of a lamp of the present invention; 
     FIG. 2 is a cross sectional view thereof, taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a partial exploded perspective view thereof, with a portion of the chimney cut away; 
     FIG. 4 is a partial cross sectional view, similar to FIG. 2, albeit of an alternative embodiment; 
     FIG. 5 is a cut-away perspective view of another alternative embodiment; and 
     FIG. 6 is a cross sectional view thereof taken along line  6 — 6  of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to FIGS. 1-3 of the present application, a lamp  10  includes a base  12  supporting a removable, open-ended chimney  14  and a removable candle  16 . The chimney  14  can be made of glass or, preferably, a heat-resistive plastic, such as a V-O flame rated polycarbonate, commercially available under the name “Makrolon® 6455” from Bayer Corporation. The chimney  14  can be translucent to allow light to pass there through while obscuring the inside of the chimney, or alternatively could be transparent. 
     The chimney  14  attaches to the base  12  with bayonet style locking tabs/legs  18  formed on the lower edge of the chimney  14  that mate with locking slots  20  formed in the top of the base  12 . The legs  18  have bent feet  22  (see FIG. 2) that pass through an enlarged area of each slot  20 , but cannot pass through a narrow area of each slot  20 . Thus, the chimney  14  is locked to the base  12  when the legs  18  are rotated into the narrow area of the slots  20 . 
     The base  12  has a skirt  24  extending around its periphery and having a plurality of outer ventilation openings  26  spaced apart around the wall  24 . The base  12  also has a recessed top wall  28  with a plurality of spaced inner openings  30 . Thus, the outer openings  26  are open to the outside air and the inner openings  30  are at the interior of the chimney  14  so that air can pass into the base  12  and up into the chimney  14 . The top wall  28  is formed with a circular shelf  32  against which rests the bottom of the chimney  14 . At the center of the top wall  28 , and thus the base  12 , is an upwardly extending mounting post  34  for mounting the candle  16 . 
     The candle  16  is contained in a candle cup  36  having a floor  38  and a cylindrical wall  40  defining an open top. The candle cup  36  is preferably made of a V-O flame rated polycarbonate material. The candle  16  is preferably a conventional cylindrical paraffin wax candle having a wick  42  held at the bottom by a wick clip  44  disposed in a depression  46  in the cup floor  38  to restrict movement of the candle  16 . A downwardly opening cylindrical socket  48  extends from the center of the cup floor  38  as does a cylindrical cup support member  50  at the periphery of the cup floor  38 . The support member  50  is at least as tall as the socket  48  to allow the candle cup  36  to sit upright on top of the base  12 . The cup socket  48  engages the mounting post  34  to grip the candle cup  36  to the base  12  so that the candle  16  does not tip over or move with respect to base  12 . The lower half of lamp  10  is preferably identical to the FIGS. 16-20 embodiment of WO 00/78135. Thus, further details regarding its preferred construction can be obtained by reading that publication. 
     In accordance with the present invention, the chimney  14  preferably includes a circular ledge  52  extending radially inwardly into its interior on which rests a coil support  54  supporting a burnable coil  56 . The burnable coil  56  is impregnated with (e.g. the material is mixed with, coated with or otherwise carries) a volatile material. Our preferred insect control active is d-cis/trans allethrin. The coil  56  is conventional (e.g. has a spiral configuration and is otherwise of the type disclosed in U.S. Pat. No. 6,066,950, e.g. see U.S. Pat. No. 5,657,574), the disclosures of which are incorporated by reference herein. 
     The coil support  54  that is shown is a disk-shaped body having a circumferential lip  58  extending radially outward beyond an annular skirt  60 . The lip  58  rests on the chimney ledge  52  to mount the coil support  54  near the top opening of the chimney  14 . The coil support  54  has a top wall  62  with a spade  64  extending up from its center. The spade  64  is sized to fit in a recess  66  in a mounting end  68  of the coil  56 . The spade  64  thus can support the coil  54  spaced off the top wall  62  to reduce the occurrence of a burning coil  54  being inadvertently snuffed out during use due to losing heat to the support. 
     The wall  62  also has a plurality of ventilation openings  70  there through allowing air to pass through the coil  56  and exit the chimney  14 . The coil support  54  is preferably made of metal. 
     The lamp  10  is used by removing the chimney  14  temporarily to light the candle  16 . The chimney  14  then re-attached to the base and the coil  56  is placed onto the spade  64  and its free end is lit. A convective air flow is generated by the heat from the candle  16 , which pulls outside air into the base  12  through the openings  26  and up through openings  30  into the chimney  14 , past the candle  16 . The air stream is then drawn up through the chimney  14  and through the openings  70  in the coil support  54  past the burning coil  56 , where the air stream mixes with the volatile material released from the burning coil  56 . The volatile laden air then passes out through the top of the chimney  14  to the surrounding outside air. 
     The openings  26  and  30  in the base  12  increase air flow through the chimney  14  to provide the proper ventilation to the candle  16  and the coil  18 . The chimney draft does not extinguish the coil  18 , in part due to the heat from the candle vapors transferred to the coil through the coil support  54 . 
     The outside air pulled through the base  12  is cool relative to the air surrounding the open flame of the candle  16 . Thus, the surrounding lower wall of the chimney  14  is cooled by the air flow from below. 
     FIG. 4 shows a partial cross-sectional view of an alternate embodiment of the dispenser lamp. Elements of this embodiment similar to those described above are referred to herein with similar reference numerals, albeit with the suffix “A”. The elements of this embodiment are identical to the embodiment described above, except for an ash catcher tray  100 . Specifically, the dispenser lamp  10 A includes a base (not shown) mounting a candle (not shown) and a translucent chimney  14 A. The chimney  14 A has an inner ledge  52 A extending into its interior on which rests the coil support  54 A supporting a burnable coil  56 A of the type described above. 
     The disk-shaped coil support  54 A has a circumferential lip  58 A extending radially outward beyond an annular skirt  60 A. The lip  58 A rests on the chimney ledge  52 A to mount the coil support  54 A near the top opening of the chimney  14 A. The coil support  54 A has a top wall  62 A with a spade  64 A extending up from its center supporting the coil  54 A off the top wall  62 A. The top wall  62 A has a plurality of ventilation openings  70 A there through allowing air to exit the chimney  14 A and pass through the coil  56 A. 
     The catcher tray  100  is suspended beneath the openings  70 A in the top wall  62 A by a hanger member  102 . 
     The tray  100  has a circular bottom  104  and an upwardly extending peripheral wall  106 . The tray  100  can catch and contain partially burnt segments of the coil  56 A that may fall through the openings  70 A in the top wall  62 A. 
     The tray  100  reduces mess and more importantly prevents coil cinders from falling onto the candle. The tray  100  can be molded integrally with the hanger member  102  and top wall  62 A (as shown), or these elements can be separately formed and then connected in any suitable manner, such as a snap fit or threaded fastener. If separately formed, the hanger and/or the tray could be made of metal. In any event, the tray  100  will also serve to disrupt the flow path of the air stream though the chimney  14 A. In particular, it will force the air column in the center of the chimney  14 A to flow outwardly to pass around its periphery. The air will then flow back toward the center of the chimney  14 A, up through the openings  70 A in the coil support  54 A and out of the chimney  14 A. This mixes the heat effect across the radius of the chimney opening, thereby providing for more uniform heating. 
     FIGS. 5 and 6 illustrate another alternate embodiment of the dispenser lamp. Elements of this embodiment similar to those described above are referred to herein with similar reference numerals, albeit with the suffix “B”. The elements of this embodiment are identical to the embodiment described above, expect for the coil support. Specifically, the dispenser lamp  10 B includes a base  12 B mounting a candle  16 B and a translucent chimney  14 B identical to that of the first described embodiment. The chimney  14 B has an inner ledge  52 B extending into its interior on which rests the coil support  54 B supporting a burnable coil  56 B of the type described above. 
     The support  54 B forms a shallow tray having a bottom  110  and an upwardly extending annular wall  112  from which extends radially outward an annular flange  114  that rests on the chimney ledge  52 B to mount the coil support  54 B near the top opening of the chimney  14 B. The bottom  110  has a spade  64 B extending up from its center supporting the coil  54 B in the air. The tray can catch and contain burnt segments of the coil  56 B that fall to reduce mess and prevents embers from falling onto the candle. The flange  114  has a plurality of ventilation slots  70 B there through allowing air to exit the chimney  14 B and pass around the periphery of the coil  56 B. The tray will force the air column in the center of the chimney  14 B to flow outwardly to the slots  70 B past the periphery of the coil  56 B and out of the chimney  14 B. 
     The invention thus provides a device particularly suitable for use as a combined outdoor lantern and insect control device. The lantern utilizes conventional burnable coils, and in a preferred form inexpensive candles. Given the exposure of the coil to the flame heat, coil burning is somewhat more rapid than is conventional for coils. Thus, this device provides quicker coverage, but may be more suitable for use at a four hour cookout rather than as an overnight camping light. 
     The candle is preferably made of paraffin wax by a process of bonding small wax granules in a compression mold. This technique is well known for producing candles with consistent dimensions and densities. The preferred candle weighs from 15 to 20 grams with a diameter of about 37 mm and has an overall height of about 20 mm at its center. A candle of this size will burn for about 4 hours. 
     Exhausted coils are replaced by removing any remaining non-burnt section of the coil, emptying the ash and attaching the mounting end of the replacement coil from the kit to the spade of the coil support. Exhausted candles are replaced by removing the chimney from the base, removing the old candle cup and attaching the replacement candle from the kit to the base by pressing the socket onto the mounting post. In a preferred form of the kit, the candle will also have a candle cup which houses it. 
     Preferred embodiments of the invention have been described above. However, these embodiments are intended to be illustrative, and not exhaustive. For example, while the dispenser is shown and described for use with an insect control active, it could instead be used to dispense aromatics, disinfectants or other volatiles. Thus, the claims should be looked to in order to assess the full scope of the invention. 
     INDUSTRIAL APPLICABILITY 
     The present invention provides an apparatus providing illumination and dispensing volatiles useful, among other things, to repel insects.