Exhaust gas muffler
The present invention includes a muffler for attachment to an engine that includes an inlet for receiving exhaust gases into the muffler, a catalyst assembly located within the muffler, and a fastener tube for fastening the muffler to the engine. A fastener tube cover covers the fastener tube and includes an outlet for exiting exhaust gases. The outlet includes a directional louver that directs the exiting exhaust gases. The fastener tube cover can retain a spark arrestor which maintains maximum spark particle size in the exiting exhaust gases.
1. Field of the Invention
The present invention is directed to an exhaust gas muffler for an engine and especially for engines used for portable tools such as a chain saw or the like.
2. Description of Related Art
Exhaust gas mufflers for internal combustion engines are well known for a long time, and have mainly been used for cars. For portable tools, such as chain saws, they have been available on the market to a small extent since the end of the 1980's. The exhaust gases are delivered to an exhaust gas muffler from an exhaust port of a cylinder. The exhaust gases are processed there and discharged out. Now it is known to utilize an oxidizing catalyst in order to reduce pollutants such as hyrdocarbons, carbon monoxide, and the like. The invention can provide a front outlet catalyst muffler that combines parts to save parts, weight, and simplify the design.
BRIEF SUMMARY OF THE INVENTIONThe present invention includes a muffler for attachment to an engine that includes an inlet for receiving exhaust gases into the muffler, a catalyst assembly located within the muffler, and a fastener tube for fastening the muffler to the engine. A fastener tube cover covers the fastener tube and includes an outlet for exiting exhaust gases. The outlet includes a directional louver that directs the exiting exhaust gases. The fastener tube cover can retain a spark arrestor, which maintains maximum spark particle size in the exiting exhaust gases.
BRIEF DESCRIPTION OF THE DRAWINGSThe invention can be understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Also, in the drawings, like reference numerals designate corresponding parts throughout the several views.
A catalyst muffler with a front outlet design provides improvements over current catalyst mufflers for small gasoline powered engines. Referring to
Referring next to
The fastener tube cover 152 is designed to control direction and diffuse the exhaust gas as it leaves the muffler. This yields a lower plane temperature that is within the parameters set forth within SAE J335, which is a standard established by the USDA for the Society of Automotive Engineers to prevent forest fires. The fastener tube cover's 152 effectiveness is enhanced by the size of an outlet 155 of the fastener tube cover 152, the deflection plate 158 in the center of the outlet 155, the slope of the fastener tube cover 152, and by a flush surface created by the fastener tube cover 152 and the muffler cover 131. In addition, the fastener tube cover 152 comprises a directional louver 154 that helps direct exiting exhaust gases. All of these features cause the gases exhausted from the outlet 155 to cling to the fastener tube cover 152 and limit the temperature of the gases exhausted through the outlet 155.
Referring back to
Mufflers mounted directly to small engines can loosen over time due to the inherent engine vibration and the contracting and expansion of the metal muffler components due to the heat cycling. One method to address this problem is to use flanged tubes, such as the first fastener tube 137 and the second fastener tube 140. These flanged tubes significantly reduce the amount of metal compressed under the mounting fasteners, such as the first fastener 143 and the second fastener 146. The fastener tubes also shield the fasteners from the exhaust gases in the diffuser 116. Another use for the fastener tubes is to significantly reduce the mounting fastener exposure to the catalyst heat. Additionally, the fastener tubes can be used to clamp the muffler body 110 to the muffler cover 131.
However, when using fastener tubes, a problem exits. The fastener tubes provide receptacles for debris such as sawdust to collect. Such collected debris can be problematic, accordingly, a cover, such as the fastener tube cover 152, is used to prevent debris from entering the fastener tubes. In the current invention, in addition to preventing debris from entering the fastener tubes, the fastener tube cover 152 can be used to hold a spark arrestor 149 in place, and to serve as an exhaust gas outlet. These multiple uses reduce the amount of components necessary to create a muffler. This eases assembly and lowers cost. Also, in the current embodiment, the location of the fastener tube cover 152 on the front of the muffler allows for easier servicing of the spark arrestor 149.
Referring to
Referring next to
Focusing for the moment on
The diffuser 116 serves as a first chamber in the muffler and channels the exhaust gases inside the catalyst assembly 123 where the exhaust gases are directed to the catalyst screen 122 by holes and slots in the diffuser 116. This gives more uniform exhaust gas distribution, which ensures that the entire catalyst screen 122 is used to the best of its potential. The diffuser 116 also can serve as a spacer inside the muffler to prevent the muffler body 110 and the muffler cover 131 from collapsing. Once the exhaust gas leaves the diffuser 116, the exhaust gas enters the surrounding catalyst assembly 123.
The catalyst assembly 123 comprises a first catalyst bulkhead 119, a second catalyst bulkhead 125 and a catalyst screen 122. A flat catalyst screen 122 is formed around a round mandrel and crimped in the edges of the catalyst bulkheads to form the catalyst assembly 123. This shape allows the greatest surface contact with the exhaust gas while transferring the least amount of thermal energy back to the muffler. In the current embodiment, a stainless steel wire cloth is coated with the PM to form the catalyst screen 122.
After passing through the catalyst assembly 123, the exhaust gas is in the muffler shell 170 (see
Although the invention is shown and described with respect to certain preferred embodiments, it is obvious that equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications, and is limited only by the scope of the claims.
Claims
1. A muffler for attachment to an engine comprising:
- a fastener tube for fastening the muffler to the engine;
- a fastener entrance port of the fastener tube;
- a fastener exit port of the fastener tube;
- the fastener entrance port of the fastener tube for facing away from the engine;
- the fastener exit port of the fastener tube for facing the engine;
- a fastener tube cover covering the fastener entrance port of the fastener tube; and
- the fastener tube cover comprises an outlet for exiting exhaust gases.
2. The muffler for attachment to an engine of claim 1 wherein the outlet has a directional louver that directs exiting exhaust gases.
3. The muffler for attachment to an engine of claim 1 wherein the outlet comprises a deflection plate.
4. The muffler for attachment to an engine of claim 1 wherein the outlet comprises a hood.
5. The muffler for attachment to an engine of claim 1 wherein the fastener tube cover can retain a spark arrestor which maintains maximum spark particle size in the exiting exhaust gases.
6. The muffler for attachment to an engine of claim 1 further comprising an exhaust port and the exhaust port is on a common side with the fastener entrance port.
7. The muffler for attachment to an engine of claim 6 wherein the exhaust port and the fastener entrance port face away from the engine.
8. The muffler for attachment to an engine of claim 6 wherein the exhaust port and the fastener entrance port are on a common surface of the common side.
9. The muffler for attachment to an engine of claim 6 wherein the exhaust port and the fastener entrance port are on a non-coplanar surface.
10. A muffler comprising:
- an attacher;
- a fastener tube cover;
- a spark arrestor;
- the attacher retains the fastener tube cover; and
- the attacher retains the spark arrestor.
11. The muffler of claim 10 wherein the fastener tube cover comprises an outlet for exiting exhaust gases.
12. A muffler comprising:
- a fastener tube cover for covering a fastener tube;
- the fastener tube cover further comprises an outlet for exhaust gases to exit through; and
- the outlet has a directional louver that directs the exiting exhaust gases.
13. The muffler of claim 12 wherein the outlet further comprises a deflection plate.
14. The muffler of claim 12 wherein the outlet further comprises a hood.
15. A muffler for attachment to an engine comprising:
- an inlet for receiving exhaust gases into the muffler;
- a catalyst assembly located in the muffler;
- a fastener tube for fastening the muffler to the engine;
- a fastener entrance port of the fastener tube;
- a fastener exit port of the fastener tube;
- the fastener entrance port of the fastener tube for facing away from the engine;
- the fastener exit port of the fastener tube for facing the engine a fastener tube cover covering the fastener entrance port of the fastener tube;
- the fastener tube cover further comprises an outlet for exit of the exhaust gases from the muffler;
- the fastener tube cover and the fastener entrance port of the fastener tube are on a common side; and
- the outlet has a directional louver that directs the exiting exhaust gases into a desired direction.
16. The muffler for attachment to an engine of claim 15 wherein the fastener tube cover can retain a spark arrestor which maintains maximum spark particle size in the exiting exhaust gases.
17. The muffler for attachment to an engine of claim 15 further comprising an exhaust port and the exhaust port is on a common side with the fastener entrance port.
18. The muffler for attachment to an engine of claim 15 wherein the outlet comprises a hood.
19. The muffler for attachment to an engine of claim 18 wherein the hood is removable from the fastener tube cover.
20. A fastener tube cover for a fastener tube of a muffler having an exhaust port, the fastener tube cover comprising:
- a fastener tube cover for covering the fastener tube;
- an outlet in the fastener tube cover for exiting exhaust gases; and
- the outlet comprises a directional louver for directing exiting exhaust gases into a desired direction.
21. The fastener tube cover for a fastener tube of a muffler having an exhaust port of claim 20 wherein the fastener tube cover can retain a spark arrestor.
Type: Application
Filed: May 27, 2004
Publication Date: Dec 1, 2005
Inventors: Paul Warfel (Texarkana, TX), Scott Ericson (Texarkana, TX), Rodney Tynes (Shreveport, LA), Roy Perryman (Nashville, TX), Christofer Ferguson (Wake Village, TX)
Application Number: 10/854,812