COLLAPSIBLE MUFFLER SYSTEM
The muffler system of the preferred embodiment includes an outer membrane adapted to operate in a collapsed mode, wherein the outer membrane defines a first volume that facilitates portability and stowage, and in an expanded mode, wherein the outer membrane defines a second volume, which is larger than the first volume, that provides attenuation and muffling of the noise signature of the power system. The muffler system further includes an inlet coupled to the outer membrane and adapted to allow the exhaust gases and sound waves from the portable power system to enter the muffler system.
This application claims the benefit of U.S. Provisional Application No. 60/755,520, filed 31 Dec. 2005 and entitled “Collapsible Muffler System”, which is incorporated in its entirety by this reference.
TECHNICAL FIELDThis invention applies to the field of muffler systems and, more specifically, to a low-acoustic-signature muffler system for a portable power system.
BACKGROUNDConventional portable power systems have very high noise levels and large acoustic signatures during operation. Although users such as fisherman and military personnel desire quieter power systems, conventional muffler systems cannot meet both the requirement of a small volume to provide adequate portability and stowage of the power system, and the requirement of a large volume to provide adequate attenuation and muffling of the noise signature of the power system. This invention provides a new and useful muffler system that meets both of these requirements.
BRIEF DESCRIPTION OF THE FIGURES
The following description of the preferred embodiment of the invention is not intended to limit the invention to this preferred embodiment, but rather to enable any person skilled in the art to make and use this invention.
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The muffler system 10 is preferably designed for the use with a power system and, more specifically, for the use with a portable power system having a noise signature. The muffler system 10 of the preferred embodiment has been specifically designed to provide adequate portability and stowage in a collapsed mode, and to provide adequate attenuation and muffling of the noise signature of the power system in the expanded mode (>40 dB). The collapsed mode is preferably equal to or less than 50%, and more preferably equal to or less than 20%, of the volume of the expanded mode. The muffler system 10, however, may be alternatively used in any suitable environment and for any suitable reason.
The outer membrane 12 of the preferred embodiment functions to operate in a collapsed mode, as shown in
The outer membrane 12 is preferably one of several variations. In a first variation, as shown in
In a second variation, as shown in
In a third variation, the outer membrane 12 includes a shape memory material and transitions from the collapsed mode to the expanded mode by changing shape due to the application of an external stimuli such as temperature, light, electricity, mechanical stress, or any suitable stimuli. In this variation, the outer membrane 12 will be in a collapsed shape and upon the application of an external stimuli, the shape of the outer membrane will change to a larger, expanded shape.
The outer membrane 12 preferably has an elliptical or circular cross-section, but may alternatively be any suitable shape, size, and thickness. The outer membrane 12 preferably transitions from the collapsed mode to the expanded mode by expanding axially, but may alternatively expand radially, expand axially while decreasing in size radially or vice versa, expand by untwisting, expand into a dome shape, as shown in
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In a third variation, the frame structure 16 includes a shape memory material adapted to transition from the collapsed mode to the expanded mode by changing shape due to the application of an external stimuli such as temperature, light, electricity, mechanical stress, or any suitable stimuli. The frame structure 16 in this variation is preferably a mesh geometry, but may alternatively be a helical geometry or any other suitable geometry that can expand from a collapsed mode to an expanded mode by changing shape.
In a fourth variation, as shown in
In a fifth variation, as shown in
The frame structure 16 preferably transitions from the collapsed mode to the expanded mode by expanding axially, but may alternatively expand radially, expand axially while decreasing in size radially or vice versa, expand by untwisting, or may increase the volume defined by the frame structure 16 in any other suitable manner. Although the frame structure 16 is preferably one of these multiple variations, the frame structure 16 may be any suitable frame structure to provide adequate portability and stowage in a collapsed mode, and to provide adequate attenuation and muffling of the noise signature of the power system in the expanded mode. In alternative variations, the muffler system 10 may include any suitable combination or permutation of the above frame structures 18.
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In an alternative embodiment, the muffler system 10 also includes a self-deployment device. The self-deployment device functions to automatically transition the outer membrane and/or the frame structure 16 from the collapsed mode to the expanded mode. The self-deployment device may further function to automatically transition the outer membrane and/or the frame structure 16 from the expanded mode to the collapsed mode. In one variation, the self-deployment device includes a thermo-mechanical method to use the exhaust heat of the portable power system to thermally expand the collapsible muffler to its operating mode. In this variation, the outer membrane 12 and/or the frame structure 16 may be made out of a shape memory material. The self-deployment device will apply external stimuli such as temperature, light, electricity, or mechanical stress causing the outer membrane 12 and/or the frame structure 16 to change shape and move from the collapsed mode to the expanded mode. In a second variation, the self-deployment device is adapted to use air or exhaust gases to inflate the outer membrane 12 and/or the frame structure 16 from the collapsed mode to the expanded mode. In another variation, the self-deployment device includes an electromechanical method to use a small, low power, electric motor to drive central lead screw that will expand and collapse the outer membrane 12 and/or frame structure 16 to achieve either the stowed-volume in the collapsed mode or the operating volume in the expanded mode.
In an alternative embodiment, the muffler system 10 also includes a catalytic converter. The catalytic converter functions to catalytically convert at least a portion of any unburnt or partially oxidized fuel and oxidants. The preferred catalytic converter facilitates portability and stowage. With the inclusion of a catalytic converter, the portable power system may have a reduced emission signature, which may allow the portable power system to be used in an enclosed space such as a room, a boat cabin, or a vehicle cabin. The catalytic converter is preferably formed as a spiral or helical member with a collapsible membrane or porous media. Additionally, the catalytic converter may be constructed in a honeycomb structure or may include ceramic beads. The catalytic converter may, however, be formed as any suitable member with any suitable material such that the maximum surface area of catalyst is exposed to the stream of exhaust gases, while also minimizing the amount of catalyst required. The catalytic converter is preferably made with conventional techniques in the art, but may alternatively be made with any suitable methods.
The elements of the muffler system 10 in the expanded mode preferably function as a conventional muffler, where the sound waves from the power system bounce around the volume defined by the outer membrane 12, canceling each other out, and additionally are absorbed by the outer membrane 12. The muffler system 10 in the expanded mode may alternatively function in any other suitable manner as to provide adequate attenuation and muffling of the noise signature of the power system. For example, the muffler system 10 may function similarly to a glass pack or a cherry bomb, which use absorption only to reduce the sound of the power system.
Although omitted for conciseness, the preferred embodiments include every combination and permutation of the various outer membranes 12, the various inlets 14, the various frame structures 16, the various outlets 18, the various first end caps 20, the various second end caps 22, the various securing elements 24, the various inner exhaust pipes 26, the various self-deployment devices, and the various catalytic converters.
As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the preferred embodiment of the invention without departing from the scope of this invention defined in the following claims.
Claims
1. A muffler system for a portable power system having a noise signature, comprising:
- an outer membrane adapted to operate in the following modes: collapsed mode, wherein the outer membrane defines a first volume that facilitates portability and stowage; and expanded mode, wherein the outer membrane defines a second volume, which is larger than the first volume, that provides attenuation and muffling of the noise signature of the power system; and
- an inlet.
2. The muffler system of claim 1 wherein the first volume is equal or less than 50% of the second volume.
3. The muffler system of claim 2 wherein the first volume is equal or less than 20% of the second volume.
4. The muffler system of claim 1 wherein the outer membrane is adapted to transition from the collapsed mode to the expanded mode by inflating.
5. The muffler system of claim 1 wherein the outer membrane includes creases and is adapted to transition from the collapsed mode to the expanded mode by unfolding.
6. The muffler system of claim 1 wherein the outer membrane includes a shape memory material and is adapted to transition from the collapsed mode to the expanded mode by changing shape due to the application of at least one of temperature, light, electricity, and mechanical stress.
7. The muffler system of claim 1 further comprising a frame structure coupled to the outer membrane and adapted to operate in the following modes:
- collapsed mode, wherein the frame structure defines a first volume that facilitates portability and stowage; and
- expanded mode, wherein the frame structure defines a second volume, which is larger than the first volume, and provides structure for the outer membrane.
8. The muffler system of claim 7 wherein the frame structure includes telescoping rods adapted to transition from the collapsed mode to the expanded mode by lengthening telescopically.
9. The muffler system of claim 7 wherein the frame structure includes a spring adapted to bias the outer membrane from the collapsed mode to the expanded mode.
10. The muffler system of claim 7 wherein the frame structure includes a shape memory material and is adapted to transition from the collapsed mode to the expanded mode by changing shape due to the application of at least one of temperature, light, electricity and mechanical stress.
11. The muffler system of claim 7 wherein the frame structure comprises a plurality of rings adapted to transition from the collapsed mode to the expanded mode by separating.
12. The muffler system of claim 7 further comprising an outlet and a first end cap coupled to the outer membrane and coupled to at least one of the inlet and the outlet.
13. The muffler system of claim 12 further comprising a second end cap coupled to the outer membrane and coupled to at least one of the inlet and the outlet.
14. The muffler system of claim 13 wherein the frame structure extends between the first end cap and the second end cap.
15. The muffler system of claim 7 further comprising a securing element adapted to hold at least one of the outer membrane and the frame structure in at least one of the collapsed mode and the expanded mode.
16. The muffler system of claim 7 further comprising a self-deployment device adapted to transition at least one of the outer membrane and the frame structure from the collapsed mode to the expanded mode.
17. The muffler system of claim 16 wherein the self-deployment device is adapted to use heat to expand at least one of the outer membrane and the frame structure from the collapsed mode to the expanded mode.
18. The muffler system of claim 16 wherein the self-deployment device is adapted to use air to inflate at least one of the outer membrane and the frame structure from the collapsed mode to the expanded mode.
19. The muffler system of claim 16 wherein the self-deployment device includes an electric motor to drive at least one of the outer membrane and the frame structure from the collapsed mode to the expanded mode.
20. The muffler system of claim 1 further comprising a catalytic converter adapted to expose the exhaust from the portable power system to a catalyst.
Type: Application
Filed: Dec 30, 2006
Publication Date: Aug 16, 2007
Inventor: James Rhett Mayor (Ypsilanti, MI)
Application Number: 11/618,759
International Classification: F01N 1/02 (20060101);