Abstract:
A liquid fuel lamp is provided with a wick carrying composite safety cap which is mountable to and removable from the liquid fuel container only by simultaneous pressing and turning actions. The safety cap has a spring biassed latch and a wick guard surrounding in a spaced manner around the upper end portion of the wick.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to liquid fuel lamps and more particularly oil lamps that may be used for illumination or decorative purposes both indoor and outdoor. It may be mounted on a post to serve as a torch for outdoor purposes. 
   2. Background Art 
   Liquid fuel lamps employ a combustible oil such as kerosene, olive oil, and mineral oil provided within a container and a wick having one end dipped into the oil may be lighted at its upper end to provide an open flame for illumination or decorative purposes. Commonly, the wick is carried on a cap mounted at the top of the oil container. The cap merely rests or is press-fitted on the container and it can be easily removed for filling the container with the liquid fuel oil. 
   Liquid fuel lamps have been problematic, particularly due to the existing of the open flame which presents a potential fire hazard if the flame comes in contact with other combustible material or due to spillage of the oil from the container particularly if the latter is accidentally tipped over or due to leakage of the oil from the container. The open flame may also cause severe burn hazard if it is contacted accidentally. The combustible oil can cause serious health hazard with lethal consequences if ingested particularly by children. Moreover, the wick is mounted on a metal cap such that the cap may be heated to a high temperature which may cause spontaneous combustion of any liquid fuel coming into contact with such heated surface. Heretofore, such unfortunate mishaps have occurred frequently. The often occurrence of such instances of mishaps induces the establishment of the stringent safety standards such as the European Standard EN14059 stipulating the basic safety construction of such lamps in order to alleviate the above safety hazards. However, to-day no liquid fuel lamps meet the requirements of such safety standards. 
   SUMMARY OF THE INVENTION 
   It is a principal object of the present invention to provide liquid fuel lamps which complies with all the safety requirements of safety standards. 
   It is another object of the present invention to provide liquid fuel lamps in which the fuel is prevented from leakage from the container. 
   It is another object of the present invention to provide liquid fuel lamps having a child-proof cap mounting for preventing the fuel oil from accidentally being ingested by children. 
   It is yet another object of the present invention to provide liquid fuel lamps in which the wick is insulated from the mounting cap. 
   It is still another object of the present invention to provide liquid fuel lamps which has a leakage-proof cap to prevent leakage of the liquid fuel oil even when the container is accidentally overturned. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments thereof in connection with the accompanying drawings in which 
       FIG. 1  is an exploded front elevation view of the liquid fuel lamp having a relatively tall liquid fuel container and one embodiment of a child-proof cap. 
       FIG. 2  is a perspective bottom elevation view of the casing of the safety cap. 
       FIG. 3  is a perspective bottom elevation view of the latching plate and the shell of the safety cap. 
       FIG. 4  is a partial sectional front elevation view of the liquid fuel lamp according to the present invention. 
       FIG. 5  is an exploded front elevation view of the liquid fuel lamp having a semi-spherical fuel container provided with a second embodiment of the safety cap according to the present invention. 
       FIG. 6  is a perspective bottom elevation view of the latch plate of the second embodiment shown in  FIG. 5 . 
       FIG. 7  is a perspective bottom elevation view of the locking collar of the second embodiment. 
       FIG. 8  is a perspective bottom elevation view of the short cylinder of the second embodiment. 
       FIG. 9  is a partial sectional front elevation view of the liquid fuel lamp with the safety cap of the second embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the drawings in which like reference numerals designate corresponding parts in the several views, the liquid fuel lamp  10  of the present invention has a container  11  preferably made of a transparent or translucent plastic material such that the amount of fuel  12  in the container  11  is visible so as to provide a readily available indication to the user of whether addition or replenishment of the fuel would be required. The container  11  has an upper neck  13  with mounting reads  14  formed thereon. A composite safety cap  15  is threadingly mountable on the neck  13 . The threaded mounting is shown as an exemplary embodiment of the present invention, it will be understood by those skilled in the art that other forms of mounting means such as a bayonet mounting may be employed to provide a similar function. The safety cap  15  has a circular adapter  16  made of a high temperature plastic or phenolic material such as Bakelite (a trade mark) and it has a circular casing  17  having mounting threads  18  formed on its inner surface such that the circular casing  17  may engage with the mounting threads or similar complementary mounting means  14  on the neck  13  of the fuel container  11  for securing to the latter. A cylindrical upper sleeve portion  19  is integrally formed on the circular casing  17  and it extends upwardly therefrom. An extended circular rim  20  having a larger diameter than the circular casing  17  is also integrally formed at the lower edge of the circular casing  17  such that it extends outwards from the circumference of the lower edge of the circular casing  17 . At least two open slots  21  are formed at diametrically opposite positions in the circular rim  20  and preferably a plurality of such open slots  21  are formed in evenly spaced diametrically opposite positions in the circular rim  20  as shown in  FIG. 2 . A generally T-shaped metal sleeve carrier  22  is mounted or integrally molded at the top portion of the upper sleeve portion  19 . The metal sleeve carrier  22  may be made of copper or brass. The main body  16  has an inner through opening  23  extending through the circular casing  17 , the upper sleeve portion  19  and the metal sleeve carrier  22 . The wick  24  for the lamp is slidably mounted in the main body  16  through the opening  23 . 
   The safety cap  15  has a generally frusto-conical or bell-shaped top shell  25  which preferably has a lower diameter larger than the diameter of the container  11  so as to prevent any kindling material from the burning wick from dropping onto the container  11 . The shell  25  has a short cylindrical top portion  26  extending upwards from its center and it has an opening  27  which has a diameter equal to the outside diameter of the upper sleeve portion  19  of the adapter  16 . A circular latching plate  28  is mounted at the bottom opening  29  of the shell  25 . The latching plate  28  has a central opening  30  which has a diameter slightly larger than the outside diameter of the casing  17  but smaller than the outside diameter of the circular rim  20 . Two vertical tabs  31  and  32  formed at diametrically opposite locations of the edge of the central opening  30 . The width of the tabs  31  and  32  is smaller than the open slots  21  formed in the circular rim  20  of the circular casing  17 . A spiral compression spring  33  is disposed around the upper sleeve portion  19  of the main body  16 . The spring  33  has an inside diameter larger than the outside diameter of the upper sleeve portion  19  and an outside diameter larger than the opening  27  at the top of the cylindrical top portion  26  so that its bottom rests on the circular casing  17  and its top is in abutment with the inner surface of the rim of the opening  27 . The main body  16  extends upwards through the opening  27  of the shell  25  and is secured in place by a spring lock washer  34  engages with a circular slot  35  formed around the upper sleeve portion  19 . The shell  25  may be pressed downwards against the spring force of the compressing spring  33  while turning to engage the tabs  31  and  32  with the open slots  21  of the circular rim  20  for turning the casing  16  for either securing or removing the safety cap  15  from the neck  13  of the container  11 . This double action requirement safeguard that safety cap  15  may not be operated by children to remove it from the container  11 . An oil seal  36  is provided between the casing  16  and the top edge of the neck  13  of the container  11  so as to prevent leakage of the liquid fuel  12  from the container  11  when the safety cap  15  is tightly mounted to the neck  13 . 
   A spiral spring  37  having an inside diameter equal to that of the cylindrical top portion  26  of the shell  25  may be mounted to the cylindrical top portion  26  to provide a safety guard for the wick  24  and the flame. The spacing between the spiral of the spring  37  is preferably less than ¼ inch so as to prevent children from accidentally touching the flame with their fingers. 
   A second embodiment of a composite safety cap  38  according to the present invention is shown in  FIGS. 5 through 9 . The safety cap  38  is particularly suitable for use with a metal fuel container  39  which has a metal top cover  40  with a central threaded opening  41 . The safety cap  38  has a metal tubular sleeve carrier  42  having a threaded lower end portion  43  which is engageable with the central threaded opening  41  of the fuel container top cover  40  for mounting thereto. The wick  24  is slidably mounted within the tubular sleeve carrier  42 . An oil seal  26  is located between the tubular sleeve carrier  42  and the container top cover  40 , and a threaded ring  44  is also mounted on the threaded lower end portion  43  of the tubular sleeve carrier  42  such that it may be adjusted to secure the oil seal  26  tightly over the opening  41  so as to prevent any leakage of liquid fuel from the container  38 . A circular latch plate  45  is fixedly mounted on the tubular sleeve carrier  42  and located above the threaded lower end portion  43 . The latch plate  45  has four evenly spaced extension tabs  46 ,  47 ,  48  and  49  formed in its periphery, in which the tabs  46  and  48  are located diametrically directly opposite to one another and the tabs  47  and  49  are similarly located directly opposite to one another diametrically. The latch plate  45  is slidably located within the lower portion of a short cylinder  50  and rotatable relative thereto. A locking collar  51  having a cross-sectional inverted U shape is fixedly mounted within the upper portion of the cylinder  50 . The locking collar  51  has a central opening  52  which has a slightly larger diameter than the outside diameter of the tubular sleeve carrier  42 . Four open slots  53 ,  54 ,  55  and  56  are formed at the lower edge of the circular side wall  57  of the locking collar  51 . The open slots  53  and  55  are located diametrically directly opposite to one another and the open slots  54  and  56  are similarly located diametrically directly opposite to one another. The width of the open slots  53 ,  54 ,  55  and  56  is slightly wider the width of the tabs  46 ,  47 ,  48  and  49  of the latch plate  45 . A spiral compression spring  58  surrounds the upper portion of the tubular sleeve carrier  42  and rests on the latch plate  45 . The upper portion of tubular sleeve carrier  42  extends through the central opening  52  of the locking collar  51  and a lock washer  59  is secured to tubular sleeve  42  by engaging with a circular slot  60  formed on the upper portion of the tubular sleeve  42 . Thus, the lock washer  59  maintains the tubular sleeve carrier  42  slidably mounted to the locking collar  51 , and the locking collar  51  is movable vertically to engage the tabs  46 ,  47 ,  48  and  49  with the open slots  53 ,  54 ,  55  and  56  by a depressing action against the spring force of the compression spring  58 . The compression spring  58  maintains the tabs normally disengaged from the open slots. Accordingly, in order to secure or to remove the safety cap  38  from the fuel container  39 , it would require both the pushing downward action and the turning action to be executed simultaneously similar to that in the embodiment described previously. A cylindrical foam tube  61  may be provided between the short cylinder  50  and the compression spring  58  to insulate the tubular sleeve  42  from the short cylinder  50 . 
   A spiral spring  37  similar to that of the above first embodiment, may also be secured to the short cylinder  50  to provide a guard for the wick as well as against accidental touching of the flame by children. 
   While the preferred embodiments of the invention have been described above. It will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.