FIRE PIT
A fire pit that is fueled by one or more small, disposable propane cylinders. In an embodiment, the small, disposable cylinder is directly connected to the fire pit without a hose. The fire pit includes a pilot light having a fuel feed and an air feed. The fuel feed is provided by a conduit that leads to an electrode for the pilot light. The air feed is provided by a perforated tube that extends around the electrode.
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This application claims priority to U.S. provisional patent application Ser. No. 60/673,987, filed Apr. 22, 2005, and incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTIONThe present invention is related to fuel burning devices, and more particularly to a fuel-powered fire pit.
BACKGROUND OF THE INVENTIONThere have been a number of backyard fireplaces known in the art, from large wood-burning units to small copper pots fueled by real wood or twenty (20) pound propane cylinders. It is also possible to fuel such devices with DURAFLAME logs or other synthetic self-contained fuel sources. Many of these fire pits are decorative in nature and feature copper bowls, stainless steel bowls, granite rings around such bowls, and other aesthetic enhancements.
SUMMARY OF THE INVENTIONThe 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 that is presented later.
In accordance with an embodiment, a fire pit is provided that is fueled by a small, disposable propane cylinder. In an embodiment, the small, disposable cylinder is directly connected to the fire pit without a hose.
In accordance with an embodiment, the fire pit includes a pilot light extending through media and having a fuel feed and an air feed. The fuel feed is provided by a conduit that leads to an electrode for the pilot light. The air feed is provided by a perforated cover that extends around the electrode.
In an embodiment, a fire pit includes a manifold for permitting the attachment of multiple propane cylinders. The manifold may include, for example, multiple input attachments for multiple propane cylinders, allowing one or more propane cylinders to be attached to the manifold to provide fuel to the fire pit.
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
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,
The embodiment shown in
Each of the fire pits 20 and 120 includes a centrally located bowl 22. In the fire pit 120 shown in
The media 34 may be, for example, a generally porous media, in this configuration, of two different levels, a lower, base level 36 (
In an embodiment, the base layer 36 of media 34 is arranged to fill from the bottom 24 to a level just above the burner 26 to allow propane to flow through the layer 36 to a surface for combustion. The size of each of the pieces in the media 34 in the base layer 36 is preferably larger than one millimeter to prevent plugging of the orifices 28, and preferably smaller than ten millimeters, more preferable below five millimeters, to keep the void space between the pieces of the base layer 36 of the media 34 small.
The shape of the material used in the base layer 36 of the media 34 may be, for example, something similar to crushed rock. The angularity of the shape also helps to reduce the void space, but round or other shaped media could be used as well. Overall, the goal is to have enough space for the propane to travel through to fill the base of the bowl and to fill the volume of the bowl as much as possible but yet constrict the movement of the propane so that it does not come up too fast. Also, the base layer 36 of the media 34 is preferably spaced tightly enough relative to one another so as to keep air from going down into the media. In this manner, combustion occurs mainly at the surface of the base layer 36, instead of within the base layer.
The second layer 38 (
In an embodiment, the fire pit 120 or 20 includes an electrode 40 (
In an embodiment, the electrode 40 passes through the base layer 36 of the media 34 and into the second layer 38. The end of the electrode 40 may slightly protrude through the second layer 38, or may only slightly extend into it, or may be located somewhere in between these two locations.
In the embodiment shown in
The tube 42 feeds fuel directly to the electrode 40. The fuel feed to the electrode 40 via the tube 42 and the air feed via the rolled piece of screen 44 permits a form of pilot light that is lit almost immediately upon starting of the fire pit 20 or 120. In the absence of fuel flow directed to the electrode 40, fuel would have to completely fill the bowl up to the level of the electrode (or close to it) to be in close enough proximity to ignite. Propane fuel, being heavier than air and being introduced at the bottom of the bowl, fills the bowl from the bottom up through the media. The fuel cannot be ignited until that fuel can mix with some air above the media, so match lighting would be very difficult or dangerous, and electronic ignition would be difficult without the fuel and air being fed to the electrode 40.
Although described as a “tube,” the tube 42 may in fact be any structure that surrounds or partially surrounds the electrode 40, referred to generally herein as a “sleeve.” The openings in the sleeve preferably extend up the sleeve so as to provide an air feed along the length and to
The burner 26 in this application is a flat, coiled tube burner with a series of small orifices 28 drilled in different orientations to facilitate distribution of the gaseous fuel. The gaseous fuel is delivered to the burner 26 through the bottom 24 of the bowl 22 or through some other part of the bowl, and the burner tube extends to a regulator 43 (
The electrode 40 may be powered by a standard igniter, such as a standard electronic ignition system provided in many fuel burning appliances. It may be, for example, battery or high energy electric powered, a piezoelectric device, or another suitable device. In an alternate embodiment, the fire pit 24 is lit using a match or a lighter.
In another embodiment, multiple burner tubes, such as the burner 26, could be installed in a common bowl, such as the bowl 22. This feature would facilitate larger bowls and more flame in the bowl.
There is a finite amount of fuel that can be pulled from a small, disposable cylinder and fuel that is pulled too fast may cause frosting of the small, disposable propane cylinder 46, thereby diminishing flow. For a large bowl, multiple burners may be used within the bowl to avoid this problem. In an embodiment, the multiple burners may be tubular in nature and run concentrically in the bottom of the bowl. The multiple burners may also be fed by multiple cylinders and multiple regulators. For example,
Turning now to
The manifold 230 includes a common conduit 231 that extends to two one-way check valves 232, 234. In accordance with an alternate embodiment, more than two canisters may be attached to a similar manifold. In such an alternate embodiment, additional one-way check valves, such as the one way check valves 232, 234, may be provided.
In the embodiment shown in the drawings, the one-way check valves 232 and 234 are similar, and thus, for ease of description, the structure of only one, the check valve 234, is described herein. As can be seen in
The one-way check valve 234 includes a standard probe 246 having a top 250 that engages the gasket 236 of the valve stem 240. The probe 246 inserts into an opening on a top of one of the propane cylinders 46 when a threaded top of the propane cylinder 46 is screwed into a threaded cylinder sleeve 252 on the one-way check valve 234. As is known, propane cylinders, such as the propane cylinders 46, include an internal valve (not shown) that is structured so that when a probe, such as the probe 246, is inserted into the top opening of the propane cylinder 46, gas is released from the propane cylinder 46.
When a propane cylinder 46 is threaded onto the cylinder sleeve 252, the cylinder sleeve 252 stabilizes and supports the propane cylinder 46. A gasket 253 seats the top of the propane cylinder 46 against the top of the cylinder sleeve 252. During attachment of the propane cylinder 46, the probe 246 is automatically inserted into an opening at the top of the propane cylinder 46. This insertion of the probe 246 into the opening opens the internal valve (previously described, but not shown) on the propane cylinder 46.
With the propane cylinder 46 in place, fuel in the propane cylinder 46 is free to escape out of the propane cylinder 46, creating gaseous fuel. This fuel flows up a conduit 254 that extends through the center of the probe. This conduit 254 extends to the valve stem 240. The pressure of the fuel flow out of the propane cylinder 46 drives the valve stem 240 away from the top 250 of the probe 246 against the bias of the spring 242, moving the gasket 236 away from the top 250 of the probe 246. Thus, the gaseous fuel is free to flow into the conduit 231 for the manifold 230. The spring 242 is a light duty spring and is chosen so that it is sufficient to drive the gasket 236 against the top 250 of the probe 246 only when a propane cylinder 46 attached to the one-way check valve 234 is empty or is substantially empty. Thus, under normal conditions, when the propane cylinder 46 is not empty, fuel within the propane cylinder 46 is free to flow out of the propane cylinder 46 and into the manifold 230 as soon as the propane cylinder 46 is attached to the one-way check valve 234. Likewise, when the propane cylinder 46 is disconnected from the one-way check valve 234, the spring 242 closes the opening in the one-way check valve 234 by driving the valve stem 240 and the gasket 236 into contact with the top 250 of the probe 246.
Any attempt of fuel or air to flow in the opposite direction (i.e., into the propane cylinder 46 from the manifold 230) is prevented because, for fuel to flow in that direction, the air and/or gas pressure in the manifold 230 must be greater than the pressure within the propane cylinder 46. However, when such a pressure differentiation is present, the spring 242 is free to drive the valve stem 240 and the gasket 236 to close the opening at the top 250 of the probe 246, preventing the flow of gas into the propane cylinder 46. This feature prevents the manifold 230 from being used to fill propane canisters.
The manifold 230 includes an outlet 310 that connects to the bottom of the regulator 302. In an embodiment, the outlet 310 is permanently connected to the regulator 302.
In accordance with an embodiment, a manifold 330 (
In use, the exterior threads 343 are threaded into a female connector for a fuel burning appliance (not shown, but described above). The female connector is designed to receive a threaded top of a propane cylinder, such as the propane cylinders 46. The female connector includes a probe, similar to the probe 246 in
By using the manifold 330, the flow of propane out of propane cylinders 46 that are attached to the manifold 330 is decreased. For example, if two propane cylinders 46 are attached to the manifold 330, then the flow rate is cut in half. If a manifold is provided to which three propane cylinders 46 may attach, then the flow rate is cut to approximately a third, and so forth. In this manner, fuel burning appliances that require a large amount of propane are less likely to freeze a propane cylinder 46 as a result of propane being drawn from the propane cylinder.
The bowl 22 is housed within a tubular frame 50. In this embodiment, the tubular frame 50 is painted steel, but another suitable material may be used. The frame 50 is segmented into multiple pieces that are bolted together. This includes decorative outer plates 52 that extend radially outward from the bowl 22 of the fire pit 20. These decorative outer plates 52 are toroidal in shape and are cut into segments to allow a smaller package for shipping, thus lowering shipping costs. In addition, the frame 50 may be a knock-down or collapsible type frame to facilitate shipping.
In an embodiment shown in
In an alternate embodiment, the cover piece 162 may be permanently attached to the frame 50, thus forming a shelf. The cover piece 160 may be formed, for example, of the same decorative material as the decorative outer plates 52.
As can be seen in
In operation, the small, disposable propane cylinder 46 is attached to the regulator 43 and a valve (not shown, but known) on the regulator is opened, for example by rotating a knob 58 on the regulator 43 to allow fuel to flow to the burner 26. The fuel is ignited by electronic ignition (e.g., using the electrode 40), or by match light or via a lighter. The preliminary stage of combustion keys a smaller flame with an equal amount of blue flame and orange flame. This flame pattern represents the oxygen in the media 34 being burned off. As that oxygen is burned off, then the fuel transitions into a much more yellow colored flame, which is the preferred look as it is much more visible, particularly at night, and gives the look of a wood fire. In an embodiment, the volume of fuel combusted/burned may be such that surface temperatures would stay below a threshold, which would allow the device to be used on a standard wooden deck without further precautions.
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 decorative fire pit, comprising:
- a fire bowl;
- media in the fire bowl;
- a burner in contact with the media and for supplying gaseous propane to the media; and
- a connector for direct connection of at least one small, disposable propane cylinder, the connector being in fluid communication with the burner.
2. The fire pit of claim 1, wherein said at least one small disposable cylinder is directly connected to the fire pit without a hose.
3. The fire pit of claim 1, further comprising a manifold for direct connection of two or more small disposable propane cylinders, the manifold being in fluid communication with the burner.
4. The fire pit of claim 3, wherein the two or more small, disposable propane cylinders are each one-pound propane cylinders.
5. The fire pit of claim 3, wherein the manifold is configured for direct connection of two or more small disposable propane cylinders via one inch threaded fittings.
6. The fire pit of claim 1, wherein the small, disposable propane cylinder is a one-pound propane cylinder.
7. The fire pit of claim 1, wherein the connector is configured for direct connection of a small disposable propane cylinders via a one inch threaded fitting.
8. A fire pit, comprising:
- a fire bowl;
- media in the fire bowl;
- a burner for supplying gaseous propane to the media; and
- a pilot light, comprising: an electrode; a sleeve surrounding at least a portion of the electrode, the sleeve extending through at least a portion of the media, the sleeve including an opening along a length of the sleeve; and a fuel feed for supplying gaseous propane from the burner to inside the sleeve.
9. The fire pit of claim 8, wherein the electrode extends through the burner.
10. The fire pit of claim 8, wherein the burner is covered by the media, and wherein the electrode and the sleeve extend out of the media or flush with the top of the media.
11. The fire pit of claim 10, wherein the sleeve comprises screen material.
12. The fire pit of claim 8, wherein the sleeve comprises screen material.
13. The fire pit of claim 8, wherein the media comprises a base media and an upper media, and wherein the sleeve and the electrode extend out of the base media.
14. The fire pit of claim 13, wherein the sleeve and the electrode extend out of the upper media.
15. The fire pit of claim 8, wherein the sleeve comprises a plurality of openings along a length of the sleeve.
16. A fire pit comprising:
- a fire bowl; and
- a decorative outer plate that extends radially outward from the fire bowl.
17. The fire pit of claim 16, wherein the decorative outer plate substantially surrounds the fire bowl and is provided in segments.
Type: Application
Filed: Apr 17, 2006
Publication Date: Oct 26, 2006
Applicant: The Coleman Company, Inc. (Wichita, KS)
Inventors: Robert Mosher (Wichita, KS), Paul Grimes (Wichita, KS)
Application Number: 11/279,949
International Classification: F24B 3/00 (20060101);