U.S. patent number 3,887,032 [Application Number 05/494,224] was granted by the patent office on 1975-06-03 for mufflers.
Invention is credited to Frank N. Harris.
United States Patent |
3,887,032 |
Harris |
June 3, 1975 |
Mufflers
Abstract
Mufflers having hollow toroids have perforated scrubbing plates
obliquely intercepting entering exhaust gases. The toroidal
chambers have partitions which divide the toroids into entrance,
intermediate and exit expansion chambers and perforated tubes
having central plugs extend through the intermediate chambers from
the entrance chamber to the exit chamber. The gases pass through
perforated scrubbing plates in the exit chambers and oblique to
elongated tailpipes.
Inventors: |
Harris; Frank N. (Portland,
OR) |
Family
ID: |
23963584 |
Appl.
No.: |
05/494,224 |
Filed: |
August 2, 1974 |
Current U.S.
Class: |
181/273; 55/319;
96/387; 55/418 |
Current CPC
Class: |
F01N
1/08 (20130101); F02B 1/04 (20130101) |
Current International
Class: |
F01N
1/08 (20060101); F02B 1/00 (20060101); F02B
1/04 (20060101); F01n 001/02 () |
Field of
Search: |
;181/49,53,54,55,56,59,63 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wilkinson; Richard B.
Assistant Examiner: Miska; Vit W.
Attorney, Agent or Firm: Klarquist, Sparkman, Campbell,
Leigh, Hall & Whinston
Claims
What is claimed is:
1. In an improved muffler,
toroidal chamber means,
inlet means opening into one portion of the toroidal chamber
means,
outlet means opening into a second portion of the toroidal chamber
means spaced around said toroidal chamber means from said one
portion,
a pair of partitions dividing the toroidal chamber means into an
inlet chamber, an outlet chamber, and two side chambers between the
inlet chamber and the outlet chamber,
one of the partitions having inlets to the side chambers and the
other partition having outlets to the outlet chamber,
and baffle means in the side chambers between the inlets and the
outlets.
2. The improved muffler of claim 1 including scrubbing means
positioned in the inlet chamber.
3. The improved muffler of claim 2 wherein the scrubbing means
comprises perforated plate means positioned obliquely to the gases
coming through the inlet means.
4. The improved muffler of claim 3 wherein the perforated plate
means includes a pair of perforated plates both oblique to the
gases and positioned between the inlet means and the inlets to the
side chambers.
5. The improved muffler of claim 4 wherein each of the baffle means
comprises a tube having perforations therein and extending from the
inlet to the outlet and having a plug between the ends thereof.
6. The improved muffler of claim 4 wherein each of the baffle means
comprises perforated tube means leading from the inlet into the
side chamber and perforated tube means leading from that side
chamber to the outlet thereof.
7. The improved muffler of claim 6 wherein the inlet means
comprises a pair of inlet openings directed obliquely toward the
pair of perforated plates in the inlet chamber.
8. The improved muffler of claim 4 wherein the inlet means
comprises a single inlet opening positioned between and directed
obliquely toward both of the perforated plates.
9. The improved muffler of claim 8 including a second pair of
perforated plates in the outlet chamber positioned on opposite
sides of the outlet means and obliquely relative to the outlet
means.
10. In an improved muffler,
an outer cylinder of a predetermined diameter,
an inner cylinder of a diameter substantially less than that of the
outer cylinder and positioned concentrically in the outer
cylinder,
top and bottom plates sealed to the cylinders and forming a
toroidal chamber therewith,
a pair of spaced partition plates joined tangentially to the inner
cylinder and joined to the outer cylinder and the top and bottom
plates to divide the chamber into an inlet chamber, an outlet
chamber, and two side chambers,
the partition plates having two pairs of aligned openings,
a pair of perforated tubes blocked off at the central portions
thereof extending through the pairs of aligned openings,
inlet means leading into the inlet chamber,
and outlet means leading out of the outlet chamber.
11. The improved muffler of claim 10 including inlet scrubbing
means positioned in the inlet chamber obliquely to the inlet
means.
12. The improved muffler of claim 11 including outlet scrubbing
means positioned in the outlet chamber between the tubes and the
outlet means.
13. The improved muffler of claim 12 wherein the inlet serubbing
means comprises a pair of perforated plates bracketing the inlet
means.
14. The improved muffler of claim 11 wherein the inlet scrubbing
means comprises a pair of perforated plates bracketing the inlet
means.
Description
This invention relates to new and improved mufflers, and has for an
object thereof the provision of new and improved mufflers.
Another object of the invention is to provide a compact muffler
having a series of perforated scrubbers alternating with a series
of expansion chambers.
A further object of the invention is to provide a muffler having a
perforated plate obliquely intercepting exhaust gases coming into
an expansion chamber thereof.
Another object of the invention is to provide a muffler in the form
of a toroid with two partitions dividing the interior into three
expansion chambers with perforated tubes connecting the three
chambers.
In the drawings:
FIG. 1 is a partially sectional, top plan view of a muffler forming
one embodiment of the invention;
FIG. 2 is a partially sectional, side elevation view of the muffler
of FIG. 1; and
FIG. 3 is a partially sectional, top plan view of a muffler forming
an alternate embodiment of the invention.
Referring now in detail to the drawings, there is shown in FIGS.
1-2 a muffler or silencer 10 forming one specific embodiment of the
invention and including annular top and bottom plates 12 and 14
welded to outer and inner, cylindrical, double walls 16 and 18 to
form a hollow toroid. Partitions 20 and 22 divide the interior of
the toroid into expansion chambers 24, 26, 28 and 30, and
perforated metal plates or screens 32 and 34 both inclined to inlet
36 block off the inlet from the two halves of the chamber 24.
Perforated scrubber tubes 38 and 40 mounted in holes 42 in the
partitions 20 and 22 have plugs 44 blocking their midpoints, and
extend through the chambers 26 and 28. Perforated metal scrubber
plates or screens 46 and 48 inclined to directions of flow and also
inclined to axis of tailpipe 50 in wall 16 separate the halves of
chamber 30 from the tailpipe. The size of the perforations in the
plates 32, 34, 46 and 48 and the tubes 38 and 40 may vary from
one-eighth of an inch to one-half of an inch, and are sized to the
engine used, and there is a multitude of perforations in these
plates and tubes. The length of the tailpipe, for best muffling,
should be at least about twenty times the internal diameter of the
tailpipe. Additional silencing may be effected by having the size
of the tailpipe somewhat smaller than the inlet, as is common in
mufflers for gasoline engines. The exhaust gases come from exhaust
pipe 52 of the engine to the inlet 36 and into the expansion
chamber 24 and against the inclined scrubbing plates 32 and 34. The
gases pass through the scrubbing plates and travel through the
halves of the expansion chamber 24, pass through the entrance
halves of the perforated scrubbing tubes 38 and 40 into the
expansion chambers 26 and 28, and flow from the expansion chambers
26 and 28 into and through the outlet halves of the tubes 38 and 40
into the halves of the expansion chamber 30. The gases flow through
the inclined scrubber plates 46 and 48 and to and through the
tailpipe 50. In one constructed embodiment, for a motorcycle, the
exhaust noise was reduced from 110 to 80 decibels. The inclined
scrubbing plates 32 and 34 of perforated metal prevent direct
impingement of the gases on metal walls to eliminate metallic
reflection of noise, and the expansions in the chambers 24, 26, 28
and 30 and the U-shaped paths from the inlet halves of the tubes 38
and 40 to the outlet halves thereof smooth out pulsations of the
gases. The diameter of the cylindrical wall 18 preferably is from
about one-third to one-half of the diameter of the cylindrical wall
16.
EMBODIMENT OF FIG. 3
A muffler or silencer 110 forming an alternate embodiment of the
invention is like the muffler 10 except that the muffler 110
includes two inlets 136 and 137 leading into expansion chamber 124
and directs exhaust gases from the inlets obliquely against
perforated metal scrubbing screens 132 and 134. The gases flow from
the chamber 124 through inlet halves of perforated scrubbing tubes
138 and 140 to expansion chambers 126 and 128, through outlet
halves of the tubes 138 and 140 to expansion chamber 130, through
perforated metal scrubbing plates 146 and 148 and through tailpipe
150. The muffler 110 has the two inlets 136 and 137 for use with
engines having twin exhausts as, for example, a V-8 engine. The
inlets and/or tailpipe can, instead of coming through holes in
outer cylindrical wall 116 come through top or bottom plates 112
and 114, with the scrubbing plates 132, 134, 146 and 148
repositioned where necessary to provide oblique impingement thereon
of the gases entering the chamber 124 and leaving the chamber
130.
The above-described mufflers or silencers 10 and 110 effectively
reduce the noise levels of the engines to which they are connected
without loss of power of the engines, and utilize all known factors
of silencing except centrifuging the gases against a plate having
many openings. The gases enter the silencers and are immediately
allowed to expand which slows the pulsations into a smoother gas
flow. The gases are then scrubbed and split to flow into two
perforated tubes, out of each tube into an expansion chamber, and
back into the tube to, in effect, make a U-turn while being
scrubbed twice in a rather short space. From the tubes, the gases
enter a third expansion and expand to an even flow substantially
free of all pulsations. The scrubbing plates 46, 48, 146 and 148
further soften any remaining noise. Specific silencing factors used
by the mufflers are expansion chambers, baffles, scrubber tubes,
dampening, nulling, split gas flow and tailpipe length. By
splitting the flows, opposing noise forces or nulling is effected.
The double wall construction of the toroidal chambers also damps
noises, and the scrubber tubes 38, 40, 138 and 140 eliminate
resonance.
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