Abstract:
An outdoor stove is provided which includes a burner to project gaseous fuel, an ignition structure capable of generating multiple sparks to ignite such fuel for cooking purpose, and a support means to hold the burner, the ignition structure and a cooking vessel.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to an outdoor cook stove utilizing gaseous fuel, in particular a stove with an igniter capable of providing multiple sparks to increase the chance of igniting the gaseous fuel to the stove burner. 
         [0003]    2. Brief Description of the Prior Art 
         [0004]    There are various kinds of outdoor cook stoves such as BBQ grill, deep fryer and stir fryer. Some of these stoves rely on a manual igniter where an operator uses to ignite the gaseous fuel released from the stove burner. A single spark igniter is incorporated in other stoves such a manual igniter is no longer needed. The single spark igniter is usually built of piezoelectric material which does not require any energy storage device such as battery. A stove equipped with a piezoelectric igniter is typically called an electronic ignition capable stove. 
         [0005]    A stove with electronic ignition capable of single spark generation is viewed as more advanced than a stove requiring manual ignition. However when such stove is used outdoor, it has a couple of drawbacks: 1) Outdoor environment might be windy, single spark proves to be difficult in successfully igniting the stove; 2) The stove might use a high pressure gas type where speed of the gas coming out of the burner orifice is so high that it is also difficult to ignite by a single spark. 
         [0006]    U.S. Pat. No. 4,156,825 teaches a construction of a piezoelectric generator capable of a series of sparks for gaseous cooking devices. However it does not show how it can be integrated into an outdoor stove. 
         [0007]    Thus there is a need for an outdoor stove with electronic igniter capable of multiple spark generation. 
       SUMMARY OF THE INVENTION 
       [0008]    The objective of the present invention is to incorporate a multiple ignition capable igniter into an outdoor stove utilizing gaseous fuel such that it can succeed to ignite more easily in an outdoor environment. 
     
    
     
       DESCRIPTION OF THE PREFERRED EMBODIMENTS 
         [0009]    The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood. 
           [0010]    With specific reference now to the figures in detail, it is stressed that the particular shown are by way of example and for purpose of illustrative discussion of the preferred embodiments of the present invention only. They are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention. The description together with the drawings should make it apparent for those skilled in the art how the several forms of the invention may be embodied in practice. In the drawings: 
           [0011]      FIG. 1  is a perspective (isometric) view of the preferred embodiment of an outdoor stove incorporating a multiple sparks capable igniter. 
           [0012]      FIG. 2  is an expanded isometric view of the igniter section of  FIG. 1 . 
           [0013]      FIG. 3  is a cross section view of the igniter section of  FIG. 2 , crossed along arrow A and looking from the top. 
           [0014]      FIG. 4  is a cross section view of the igniter section of  FIG. 2 , crossed along arrow B and looking from the front. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]      FIG. 1  illustrates an outdoor stove  10  constructed according to the preferred embodiment of the present invention. Stove  10  consists mainly of a cooking vessel support  100 , a burner  200  and an igniter  300 . Support  100  has multiple legs  120  to support the entire structure on a cooking surface which can be a cook top, a table or even the ground. Support  100  also has multiple stand-offs  110  on its top adapted to hold a round bottom cooking vessel. A flat bottom pan can also sit well on top of the stand-offs. Support  100  also has a plate  130  which is used to mount the burner  200 . 
         [0016]    Burner  200  of stove  10  has two burner rings  240  and  250 . Bottom of  240  has mounting holes to be mounted on plate  130  with bolts. Rings  240  and  250  consist of multiple holes  260  from where mixture of gaseous fuel and air is ejected out to be ignited. Flames from holes  260  heat a cooking vessel on top for food preparation. The mixture of gaseous fuel and air coming to burner holes  260  is delivered through a pipe structure  230 . Within pipe structure  230  there are two pipes  210  and  220  separately supplying to rings  240  and  250 . 
         [0017]    The mixture of gaseous fuel and air in pipes  210  and  220  are ejected from orifice structures  390  and  410 . Orifice structures  390  and  410  are part of igniter structure  300 . As illustrated by  FIG. 2  and  FIG. 3 , orifice structure  390  further consists of an orifice  610 , air inlets  510  and air shutter  400 . Orifice structure  410  further consists of an orifice  600 , air inlets  440  and air shutter  420 . Pressured gas fuel arrives at orifices  600  and  610  from pipes  630  and  640 . Pipes  630  and  640  are also part of the igniter structure  300 . Because of limited diameters of orifice  600  and  610 , the pressured gas fuel expands out into the orifice structures  410  and  390  by carrying air from inlets  440  and  510 . If the air shutter  420  and  400  are not entirely covering pipes  210  and  220 , the high speed mixture of gas fuel and air from orifice structures  410  and  390  further sucks more air from the openings between air shutter  420  and pipe  220  as well as air shutter  400  and pipe  210 . 
         [0018]    The pressured gas fuel to orifices  600  and  610  is delivered from pipe  340 , through pipe  620 , controlled by valve  650 , through pipes  640 ,  700  and  630 . Initial position of valve  650  does not permit pressured gas fuel to go through from pipe  620  to either  700  or  640 . Pipe  700  is further connected to pipe  630  where orifice  600  is mounted. Valve  650  is engaged with shaft  370  and can be turned counter-clockwise by shaft  370 . A knob  310  can be mounted on shaft  370  to further facilitate the turning operation. During the process of turning shaft  370  counter-clockwise, the hole  660  on valve  650  turns toward pipe  620 . This starts to permit gas fuel from pipe  620  to pass through to pipes  700  and  640 . Through pipes  700 ,  630  and  640 , the gas fuel reaches orifices  600  and  610 , expands to mix with air into pipes  210 ,  220  to reach burner rings  240 ,  250  and is ready to be ignited. 
         [0019]    Please refer to  FIGS. 3 and 4  for the operation of the igniter  300 . When shaft  370  is pushed in, it engages the entire ignition control structure  650  by utilizing locking mechanism of  370 A and  650 A. When shaft  370  is turned counter-clockwise, ignition structure  650  is also turned counter-clockwise. In this case, hole  660  is directed toward pipes  620  and  340  to accept incoming gas fuel. Shaft  370  also push open pin  710 . Opening pin  710  allows the gas fuel to come through hole  670  which also turns to align with ignition pipe  430  ( FIG. 8 ). The gas fuel is then carried through pipe  430  to the ignition orifice  320  from where the gas fuel is ejected and ready to be ignited by a spark generated by a piezoelectric element  830 . After ignition is completed, shaft  370  is released. Pin  710  returns to its original position of shutting off the gas fuel path to hole  670  by using pressure from spring  690 . Releasing shaft  370  also releases the engagement between  370 A and  650 A (thus shaft  370  and ignition control  650 ) by pressure of spring  460 . 
         [0020]    In  FIG. 4 , pressing and turning shaft  370  engages ignition control  650 .  650  further turns metal piece  800 . Metal piece  800  consists of 3 protruded fingers  800 A,  800 B and  800 C. These fingers are spaced out evenly in 30 degree angle. When  800  is carried by  650  for a counter-clockwise turn, finger  800 C first touches finger  810 A of piezoelectric hammer  810  and carries the hammer  810  toward the right against the spring  820 . In less than 30 degrees  800 C releases finger  810 A. Hammer  810  is allowed to go to its left to strike the piezoelectric element  830  by use of compressed pressure from spring  820 . The strike on piezoelectric element  830  by hammer  810  generates a high voltage which is carried by wire  360 . wire  360  is routed to proximity of orifice  320  to start the ignition flamer. When ignition control  650  is further turned counter-clockwise by shaft  370 , finger  800 B starts to touch finger  810 A of hammer  810 . Finger  800 B repeats the process made by  800 C to make another spark to be carried by wire  360  to orifice  320 . When shaft  370  is further turned counter-clockwise,  800 A is used to generate the 3 rd  spark. Thus the entire ignition structure  300  is capable of igniting sparks multiple times for stove  10 . 
         [0021]    It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive. The scope of the invention will be indicated by the appended claims rather than by the foregoing description. And all changes, which come within the meaning and range of equivalency of the claims, are therefore intended to be embraced therein.