COMPRESSOR FOR LIQUID FUEL CANISTER

Abstract

A compressor 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. 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.

Description

REFERENCE TO RELATED APPLICATION

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

The present invention relates to burner appliances, and more specifically to liquid fuel burner appliances.

BACKGROUND OF THE INVENTION

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.

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.

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.

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

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.

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.

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.

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.

In addition, because the compressor relies on air from outside the fuel canister, the fuel canister may be oriented in any direction during pressurization.

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

FIG. 1 is a side view of a fuel canister incorporating a compressor in accordance with an embodiment;

FIG. 2 is a side perspective view of the compressor of FIG. 1;

FIG. 3 is a diagrammatical section view taken along the section lines 3-3 in FIG. 2;

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;

FIG. 5 is a detailed view of the check valve of FIG. 4, with the check valve in an opened position;

FIG. 6 is an exploded, side perspective view of a portion of the compressor of FIG. 2;

FIG. 7 is a diagrammatical sectional view taken along the section lines 7-7 of FIG. 2;

FIG. 8 is a diagrammatical sectional view, similar to FIG. 7, showing a further stage of advancement of the compressor;

FIG. 9 is a side perspective view of an alternate embodiment of a compressor;

FIG. 10 is an exploded side perspective view of the compressor of FIG. 9;

FIG. 11 is a sectional view taken along the section lines 11-11 of FIG. 9;

FIG. 12 is a sectional view, similar to FIG. 11, showing a further stage of movement for the compressor; and

FIG. 13 is a sectional view of an alternate embodiment of a compressor.

DETAILED DESCRIPTION

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

Claims

1. A burner appliance, comprising:

a fuel canister comprising a rotary compressor for compressing the contents of the fuel canister.

2. The burner appliance of claim 1, wherein the fuel canister comprises an opening at a top end, and wherein the rotary compressor is positioned over and closes the opening.

3. The burner appliance of claim 2, wherein the fuel canister comprises a dip tube.

4. The burner appliance of claim 3, further comprising an outlet tube in fluid communication with the dip tube and configured to provide an air and fuel mixture from the dip tube to the burner appliance.

5. The burner appliance of claim 2, further comprising a handle on an outer portion of the rotary compressor, rotation of which causes the rotary compressor to compress air inside the fuel canister.

6. The burner appliance of claim 1, wherein the burner appliance comprises either a camping stove or a lantern.

7. The burner appliance of claim 1, wherein the rotary compressor comprises:

a plurality of pistons positioned in radially aligned cylinders, each piston having a longitudinally aligned socket;

a central rocker plate; and

for each of the pistons, a rod connected at one end to the rocker plate, and including a ball joint end mounted for movement along the socket of the piston, the rod arranged to pull and push the piston in the corresponding cylinder as a result of rotation of the rocker plate.

8. The burner appliance of claim 7, wherein for each piston, an opening is positioned at the distal end of the socket, the ball joint end of the rod closing the opening when the rod is pushing the piston, and moving away from the opening to allow the passage of gas into the cylinder when the rod is pulling the piston.

9. The burner appliance of claim 8, wherein for each piston, the rod is seated within a gap defining inner side edges, and the rod defined outer side edges, and wherein the outer side edges of the rod engage the inner side edges just as a transition occurs for the rod going from pushing of the piston into the respective cylinder to pulling of the piston out of the cylinder.

10. The burner appliance of claim 7, wherein for each piston, the rod is seated within a gap defining inner side edges, and the rod defined outer side edges, and wherein the outer side edges of the rod engage the inner side edges just as a transition occurs for the rod going from pushing of the piston into the respective cylinder to pulling of the piston 36 out of the cylinder.

11. The fuel canister for the burner appliance of claim 1.

12. A burner appliance, comprising:

a fuel canister comprising a horizontally opposed compressor for compressing the contents of the fuel canister.

13. The burner appliance of claim 12, wherein the fuel canister comprises a dip tube.

14. The burner appliance of claim 13, further comprising an outlet tube in fluid communication with the dip tube and configured to provide an air and fuel mixture from the dip tube to the burner appliance.

15. The burner appliance of claim 12, further comprising a handle on an outer portion of the compressor, rotation of which causes the rotary compressor to compress air inside the fuel canister.

16. The burner appliance of claim 12, wherein the compressor comprises:

a crankshaft attached to the handle; and

one and only one push rod attached to a pair of pistons, each of the pistons extending into a respective cylinder, the push rod including a slot into which the crankshaft extends, wherein rotation of the handle and the crankshaft causes a back and forth movement of the pistons in the cylinders, drawing air into the compressor, and forcing the air into the fuel canister so as to compress the contents of the fuel canister.

17. The burner appliance of claim 16, wherein each of the pistons includes a central bore, and a one-way valve mounted in the central bore for drawing air into the cylinder as the piston withdraws.

18. The burner appliance of claim 12, wherein the compressor comprises:

a crankshaft attached to the handle;

a pair of pistons extending into a respective cylinder; and

for each piston, a push rod attached to the piston and the crankshaft, wherein rotation of the handle and the crankshaft causes a back and forth movement of the pistons in the cylinders, drawing air into the compressor, and forcing the air into the fuel canister so as to compress the contents of the fuel canister.

19. The burner appliance of claim 18, wherein for each piston, the piston comprises a longitudinally aligned socket, and the rod includes a ball joint end mounted for movement along the socket of the piston, and wherein for each piston, an opening is positioned at the distal end of the socket, the ball joint end of the rod closing the opening when the rod is pushing the piston, and moving away from the opening to allow the passage of gas into the cylinder when the rod is pulling the piston.

20. The burner appliance of claim 12, wherein the burner appliance comprises either a camping stove or a lantern.

21. The fuel canister for the burner appliance of claim 12.