Patent Document

REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application claims the benefit of U.S. Provisional Patent Application No. 60/820,934, filed Jul. 31, 2006, and incorporated herein in its entirety. 
     
     TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates to burner appliances, and more specifically to liquid fuel burner appliances. 
       BACKGROUND OF THE INVENTION 
       [0003]    Liquid fuel camp stoves and lanterns for camping and outdoor use are well known and are described, for example, in U.S. Pat. No. 3,876,364, which is owned by The Coleman Company, Inc., assignee of the present invention. Liquid fuel that is used in such camp stoves and lanterns may be, for example, COLEMAN brand fuel, white gas, unleaded gasoline, or other liquid fuels. 
         [0004]    In conventional liquid fuel camp stoves such as the ones which The Coleman Company, Inc. has offered for many years, fuel is contained in a pressure vessel or fuel tank (hereinafter “fuel canister”) into which air is pumped under pressure. As described in U.S. Pat. No. 3,876,364, the fuel canister is equipped with a dip tube which extends to nearly the bottom of the canister. The dip tube is closed at the bottom with the exception of a small diameter orifice through which fuel is allowed to enter. The dip tube has an internal conduit which is open at the bottom and which communicates with the upper part of the fuel canister above the maximum intended fuel level. The small diameter orifice supplies fuel and the internal conduit supplies air for an air/fuel mixture that is supplied by the dip tube to a burner appliance. 
         [0005]    To aid in feeding the air/fuel mixture to a burner appliance, the fuel canister is pressurized. Prior art fuel canisters include a manual pump to pressurize the canister. The pumps for such fuel canisters can be awkward, because a user has to grip the fuel canister and place his or her thumb over the end of a rod for the pump, and then pump the canister 10 to 20 times to provide adequate pressurization. In addition, the pump mechanism often extends well into the fuel canister, limiting the volume of fuel the canister can hold. 
         [0006]    Another downside to prior art fuel canisters is that the air that is pressurized comes from the inside of the fuel canister via a small conduit. The small conduit must be arranged above the maximum fuel level while the pump is being operated. Thus, the fuel canister must be oriented properly to maintain the end of an air inlet for the pump above the fuel level. If the fuel canister is oriented the wrong way, or is tipped over, air to the pump may be blocked. 
       SUMMARY OF THE INVENTION 
       [0007]    The following presents a simplified summary of some embodiments of the invention in order to provide a basic understanding of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some embodiments of the invention in a simplified form as a prelude to the more detailed description of some embodiments that are presented later. 
         [0008]    In accordance with an embodiment, a compressor is provided for a fuel canister. The compressor includes a handle or other device for rotating a shaft. Rotation of the shaft causes the operation of pistons, which drive air into the fuel canister, thus pressurizing the fuel canister. 
         [0009]    In an embodiment, the compressor is a rotary style compressor. In another embodiment, the compressor is a horizontally opposed compressor system. Other compressor configurations may be used. 
         [0010]    In accordance with an embodiment, the compressor is mounted mostly or fully outside the fuel canister, thus permitting the fuel canister to be filled with fuel. 
         [0011]    In addition, because the compressor relies on air from outside the fuel canister, the fuel canister may be oriented in any direction during pressurization. 
         [0012]    Other features of the invention will become apparent from the following detailed description when taken in conjunction with the drawings, in which: 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a side view of a fuel canister incorporating a compressor in accordance with an embodiment; 
           [0014]      FIG. 2  is a side perspective view of the compressor of  FIG. 1 ; 
           [0015]      FIG. 3  is a diagrammatical section view taken along the section lines  3 - 3  in  FIG. 2 ; 
           [0016]      FIG. 4  is a detailed view of a one-way check valve for the compressor of  FIG. 2 , with the check valve in a closed position; 
           [0017]      FIG. 5  is a detailed view of the check valve of  FIG. 4 , with the check valve in an opened position; 
           [0018]      FIG. 6  is an exploded, side perspective view of a portion of the compressor of  FIG. 2 ; 
           [0019]      FIG. 7  is a diagrammatical sectional view taken along the section lines  7 - 7  of  FIG. 2 ; 
           [0020]      FIG. 8  is a diagrammatical sectional view, similar to  FIG. 7 , showing a further stage of advancement of the compressor; 
           [0021]      FIG. 9  is a side perspective view of an alternate embodiment of a compressor; 
           [0022]      FIG. 10  is an exploded side perspective view of the compressor of  FIG. 9 ; 
           [0023]      FIG. 11  is a sectional view taken along the section lines  11 - 11  of  FIG. 9 ; 
           [0024]      FIG. 12  is a sectional view, similar to  FIG. 11 , showing a further stage of movement for the compressor; and 
           [0025]      FIG. 13  is a sectional view of an alternate embodiment of a compressor. 
       
    
    
     DETAILED DESCRIPTION 
       [0026]    In the following description, various embodiments of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the embodiment being described. 
         [0027]    Referring now to the drawings, in which like reference numerals represent like parts throughout the several views,  FIG. 1  shows a fuel canister  20  incorporating an embodiment of the invention. The fuel canister  20  includes a conventional dip tube  22 . As is known, a dip tube is designed to take a compressed fuel/air mixture from the air portion of a fuel canister directly to the stove or appliance. A dip tube extends down into a canister, and includes a vertical portion that extends up beyond the fuel line. The vertical portion of the dip tube permits compressed air to be drawn into the dip tube. This air is mixed with fuel, for example via an orifice at the elbow of the dip tube, so that the air and fuel mixture may be supplied to an appliance. 
         [0028]    In accordance with an embodiment, a rotary compressor  24  is positioned over and closes an opening at an end of the fuel canister  20 . The compressor  24  forces air into the fuel canister  20 , compressing the contents of the canister. The dip tube  22  may then be used to take the air/fuel mixture from the canister directly to the appliance. 
         [0029]    An outlet tube  26  is provided that is in fluid communication with the dip tube  22 . The outlet tube  26  provides an air and fuel mixture from the dip tube  22  to a burner appliance, such as a stove, lantern, or other liquid fuel burner appliance. Operation of such burner appliances and the dip tube  22  are known. 
         [0030]    A handle  30  is provided on an outer portion of the rotary compressor  24 . Briefly described, a user rotates the handle  30  so that the rotary compressor  24  provides compressed air inside the fuel canister  20 . 
         [0031]    The rotary compressor  24  includes a canister interior side  34  ( FIG. 2 ). Pistons  36  (best shown in  FIG. 7 ) are positioned around a periphery of the interior of the rotary compressor  24 . The pistons  36  are positioned in radially aligned cylinders  38 . Each of the cylinders  38  may be formed, for example, by boring out a section of metal that forms the rotary compressor  24 . In the embodiment shown in the drawings, an end plate  39  is provided at an end of each cylinder  38  to close the cylinder. 
         [0032]    Each of the pistons  36  is attached to a rod  40 . The rods  40  each include ball joint ends  42 ,  44 . An outer ball joint end  44  is connected to the respective piston  36 , and an inner ball joint end  42  is connected to a central rocker plate  46 . 
         [0033]    The rocker plate  46  is centrally located in the rotary compressor  24  and includes six sockets  48  around an outer perimeter. In the embodiment shown in the drawing, the sockets  48  are formed between six arms, each having a head  50  and a narrower neck  52 . The outer ball joint ends  44  of the rods  40  are captured between adjacent necks  52 . 
         [0034]    Each of the pistons  36  includes an elongate socket  54 . Each of the outer ball joint ends  44  is positioned in one of the elongate sockets  54 . The ball joint ends  44  are free to move along, but not out of, the elongate sockets  54 . An opening  56  is positioned at the end of each of the elongate sockets  54 . 
         [0035]    A rotary plate  60 , shown in  FIG. 3 and 8 , is positioned for rotation with the handle  30 . An eccentric pin  62  extends upward out of a crankshaft that extends through the rotary plate  60 . The eccentric pin  62  extends through a center of the rocker plate  46 . The rocker plate  46  is rotatably mounted on this eccentric pin  62 . 
         [0036]    As can be seen in  FIG. 3 , air inlets  64  are positioned at the handle side of the rotary compressor  24 . On the opposite, canister-interior side  34  of the rotary compressor  24  are positioned one-way valves  66 . In the embodiment shown in the drawings, a one-way valve  66  is provided for each of the cylinders  38 . As can be seen in  FIGS. 4 and 5 , each one-way valve  66  includes an opening  68 , a ball  70 , a spring  72 , and outlet  74 . A different structure may be provided for the one-way valves  66 . 
         [0037]    In operation, a user rotates the handle  30 , causing the rotary plate  60  to rotate. The eccentric pin  62  causes the rocker plate  46  to move in a circular pattern around the interior of the rotary compressor  24 . Two different positions of the rocker plate  46  are shown in  FIGS. 7 and 8 . 
         [0038]    As the rocker plate  48  moves around the interior of the rotary compressor  24 , the rods  40  are alternatively pushed and pulled, causing the pistons  36  to move in and out of the cylinders  38 . Also, during the rotation of the rocker plate  46 , the rods  40  change their angle of attack relative to the respective pistons  36 . For example, the rod  40  in the upper right hand corner of  FIG. 8  is approaching the piston  36  from a left, interior side of the piston. The rods  40  at the bottom of that figure are in almost straight alignment with the respective pistons  36 , and the rod in the upper left hand corner is approaching the piston from an interior right direction. 
         [0039]    In accordance with an embodiment, as the rocker plate  46  travels in the circle around the interior of the rotary compressor  24 , edges of the rod  40  engage the heads  50  of the arms for the rocker plate. This engagement occurs just as the transition changes from the respective rod  40  going from pushing of the piston  36  into the respective cylinder  38  to pulling of the piston  36  out of the cylinder. This contact of the respective rod  40  with the head  50  ensures that an over stroke of the respective piston does not occur and that the rod does not move too far. 
         [0040]    As can be seen in  FIGS. 7 and 8 , when the rocker plate  46  is pressing the rods  40  to drive the pistons  36  into the cylinder  38  (e.g., the pistons on the left of  FIG. 7  and on the right of  FIG. 8 ), the end of the outer ball joint end  44  of the respective rod is driven fully into the elongate socket  54 . In accordance with an embodiment, when the outer ball joint end  44  is in this position, it closes the respective opening  56  at the end of the piston  36 . In this manner, air trapped behind the piston  36  cannot flow back through the piston, and the air is compressed in the cylinder  38 . As air is compressed in the cylinder  38 , the air presses back on the piston  36 , forcing the opening  56  into firmer contact with the outer ball joint end  44 . Thus, the higher the pressure in the cylinder  38 , the greater the seal provided by the outer ball joint end  44 . 
         [0041]    When the rocker plate  46  pulls a rod  40  so as to pull a piston  36  out of the cylinder  38  (e.g., the pistons on the right of  FIG. 7  and on the left of  FIG. 8 ), the outer ball joint end  44  of the rod moves to the interior section of the respective elongate socket, and away from the opening  56 . In accordance with an embodiment, when the outer ball joint end  44  is in this position, air is free to flow through the opening  56 , filling the cylinder  38  for the next compression by the piston  36 . 
         [0042]    The operation of the pistons  36  by the rocker plate  46  and the rods  40  can be seen in  FIG. 3 . In that figure, arrows are used to show air flowing into the air inlets  64 . This air may travel into the elongate socket  54  for the piston  36  on the left side of the figure, because the outer ball joint end  44  of that piston has moved away from the opening  56  at the end of the elongate socket. Vacuum draws air into the cylinder  38  as the piston  36  retracts. This air is driven into the cylinder  38  and awaits the next inward stroke of the piston  36  so that it may be compressed. In contrast, on the right hand side of  FIG. 3 , the piston  36  is pressed fully into the cylinder  38 . When the piston  36  moves to this position, air in the cylinder is compressed and is not permitted to escape through the opening  56  because that opening is closed by the outer ball joint end  44  of the rod  40 . 
         [0043]    As the air is compressed in the cylinder  38 , it is released by the one-way valve  66  for the respective cylinder  38  when the pressure within that cylinder reaches the pressure threshold of the one-way valve  66 . Thus, as this pressure threshold is reached, the ball  70  moves backward away from the opening  68 , against the bias of the spring  72 , as is shown in  FIG. 5 . At this position, the compressed air from the cylinder  38  is free to flow into the fuel canister  20 . In this manner, compressed air is provided in the fuel canister  20 . 
         [0044]    After the compressed air has reached a desired level within the fuel canister  20 , the user may stop rotation of the handle  30 . If additional pressure is needed at a later time, the user may simply rotate the handle  30  again. 
         [0045]    An alternate embodiment of a compressor  100  is shown in  FIG. 9 . The compressor  100  includes a handle side  102  to which a handle  101  is attached. A canister side  104  is opposite the handle side, and attaches on top of a fuel canister, such as the fuel canister  20 . A crankshaft  106  ( FIG. 10 ) is attached to the handle  101  and extends inward from the handle side  102 . The crankshaft  106  extends through a slotted opening  108  for a push rod  110 . Two pistons  112  are formed on opposite ends of the push rod  110 . Each of the pistons  112  extends into a respective cylinder  114 . End caps  116  close off the ends of the cylinders  114 . 
         [0046]    As can best be seen in  FIGS. 11 and 12 , each of the pistons  112  includes a central bore  120 . A one-way valve  122  is mounted in the central bore and in the embodiment shown in the drawings includes a ball  124  that is biased into position by a spring  126 . In a normal, biased state, the ball  124  seats against a narrowed neck of the bore  120 , closing the bore  120 . 
         [0047]    Each of the cylinders  114  includes an outlet  130  into which is seated a one-way valve  132 . In the embodiment shown in the drawings, the one-way valve  132  is a ball  134  that is biased to close an opening by a spring  136 . 
         [0048]    Air inlets  140  are provided on the handle side  102  of the compressor  100 . An outlet  142  is provided on the canister side  104  of the compressor  100 . 
         [0049]    In operation, a user turns the handle  101 , causing the crankshaft  106  to rotate. Rotation of the crankshaft  106  causes the push rod  110  to slide back and forth in the compressor  100 , driving the pistons  112  in and out of their respective cylinders  114 . 
         [0050]    As a piston  112  is pulled out of its respective cylinder  114 , the vacuum of the cylinder draws the ball  124  of the one-way valve  122  rearward, and air is free to flow through the bore  120  and into the cylinder  114 . In this manner, the cylinder  114  is filled with air as the piston  112  is retracting. 
         [0051]    As a piston  112  is driven into its respective cylinder  114 , the air behind the piston is compressed in the cylinder  114 . The one-way valve  122  does not permit air to flow out of the cylinder through the bore  120 . 
         [0052]    The compressed air in the cylinder  114  flows out of the one-way valve  132  and through the outlet  142  and into the fuel canister  20 . In this manner, after the pressure thresholds for the one-way valves  132  have been reached, compressed air is driven into the fuel canister on each half rotation of the crankshaft  106 . 
         [0053]      FIG. 13  shows an alternate embodiment of a compressor  200  that is similar to the compressor  100 , but instead of including the single push rod  110  connected to a crankshaft  106 , the compressor  200  includes a crankshaft  206  attached to two individual push rods  210 . These push rods act in much the same manner as the rods  40  described with respect to the first embodiment in that they drive the pistons  212  into the respective cylinders  214  and are seated in elongate slots  216  with openings  218 . These elongate slots  216  and openings  218  work in conjunction with rounded ends of the push rods  210  to serve as one-way valves so that appropriate compression and air intake takes place inside the cylinders  214 . 
         [0054]    The compressors  24 ,  100  and  200  are advantageous in that they may be easily attached to or disconnected from a fuel canister, for example by using a threaded attachment, or a friction fit onto the end of the fuel canister. In addition, the compressors  24 ,  100  and  200  do not require interior space to the fuel canister, permitting a user to put more liquid fuel into the canister. The compressors  24 ,  100 ,  200  are easily operated by a user, by the simple rotation of a handle. 
         [0055]    Other operations may be used to drive the pistons, but handles are inexpensive mechanisms that may be used for this operation. Other pistons may be used, or other compressor and/or cylinder arrangements. In addition, because the compressors  24 ,  100 ,  200  rely on air from outside the fuel canister  20 , the fuel canister may be oriented in any direction during pressurization, without concern for fuel flowing into an air intake (during operation, however, the orientation of the dip tube  22  should be considered). 
         [0056]    Other variations are within the spirit of the present invention. Thus, while the invention is susceptible to various modifications and alternative constructions, a certain illustrated embodiment thereof is shown in the drawings and has been described above in detail. It should be understood, however, that there is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. 
         [0057]    All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0058]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0059]    Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Technology Category: 2