Improvements in Exhaust Silencers for Internal Combustion Engines and the like.
Year: 1899

page_text: Reprinted as amended in accordance with the decision of the Chief Examiner,
dated the 15th day of August, 1900.
.
Date of Application, 14th June, 1899
Complete Specification Left, 12th Mar., 1900-Accepted, 28th Apr., 1900
PROVISIONAL SPECIFICATION.
Improvements in Exhaust Silencers for Internal Combustion Engines
and the like.
I, ANTHONY GEORGE NEW, of "The Voltage," Woking, in the County of Surrey,
Engineer, do hereby declare the nature of this invention to be as follows:-
The object of the present invention is to prevent or reduce any noise caused by
the exhaust gases issuing from internal combustion engines and the like to the
atmosphere and is particularly intended for use on motor driven vehicles propelled by
such engines. Hitherto exhaust boxes have been used for effecting this purpose and
the exhaust gases have been allowed to expand while passing through free or baffled
passages in them. Although these boxes bave been found to considerably reduce
the sound, large and complicated ones are necessary in order to render it completely
inaudible because of the high velocity at which the exhaust gases enter and the
consequent disturbance set up therein. The present invention consists in providing
a valve which completely closes the exit passage from the exhaust box-to the atmos-
phere during each cycle of the engine at that period at which noise tends to occur
and which opens again during each cycle to allow the exhaust gases to escape as soon
as their state of disturbance in the box has subsided. By this means I am able to
obtain a better effect while using a smaller or less complicated exhaust box.
Instead of using only one exhaust box I may use two or more in which cases I
place similarly acting valves between each.
I may actuate the valve or valves in any convenient manner either positively, by a
cam or similar device on the engine cam or other shaft, or automatically, by allowing
the velocity of the exhaust gases to close the valve which normally tends to remain
open.
Tind this 10th day of 1900
Improvements in Exhaust Silencers for Internal Combustion Engines
and the like.
I, ANTHONY GEORGE NEW, of The Voltage, Woking, in the County of Surrey,
Engineer, do hereby declare the nature of this invention and in what manner the
гр.
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page_text: same is to be performed, to be particularly described and ascertained in and by the
following statement:―
The object of the present invention is to prevent or reduce any noise from being
caused by the exhaust gases issuing from oil or gas engines and the like to the
atmosphere and is particularly applicable for use on motor driven vehicles propelled
by such engines.
Hitherto the exhaust gases have been led through a suitable pipe from the exhaust
valve to a box or quitener and there allowed to expand while passing through free or
baffled passages in it and bave then been free to escape into the atmosphere.
In order to render the gases noiseless large or complicated exhaust boxes have been
necessary as otherwise the velocity at which the gases issue from the box is sufficiently
high to create noise.
The present invention consists in the use of a valve or its equivalent which is
capable of completely closing the passage through which the exhaust gases issue from
the exhaust box to the atmosphere and which is so arranged that it closes that passage
during the period at which the exhaust gases would otherwise issue noisily and opens
it when their velocity has more or less subsided during each cycle of operations of
the engine.
By the use of this device a smaller and less complicated exhaust box may be
employed and a more effective silencing obtained.
In certain cases a second box inay be advantageously employed to receive the gases
which issue through the valve at the exit from the first box, this second box being
similarly provided with a controlling valve in its exit passage. Any number of boxes
may be added in this manner.
In cases where more than one engine cylinder is working and when the explosions
in each are non-coincident separate boxes with valves may preferably be used but if
only one box or series of boxes is used for a two-cylinder engine of the kind then the
valve or valves would be arranged to open and close twice during each cycle of the
engine.
To carry my invention into effect I may either provide means by which the valve
controlling the escape of the exhaust gases from an exhaust box is actuated
automatically by the velocity of the gases themselves. or by which-it-is-operated
mechanically, either-by-direct-genring-or-through-the-intervention of electrical,
hydraulie-or-pneumatie-means of transmission,-by-the engine-itself.
I prefer to actuate the valve in such a manner that it closes suddenly and opens
gradually but I may vary the rapidity as also the relative moments of either of its
actions to suit individual requirements.
In order to show and more fully describe this invention I will refer to the drawings
attached hereto which show two one methods of construction: and also a specific
alternative method whereby the same effect is obtained by a mechanical arrangement.
Fig. 1 is a longitudinal section of an automatically operated silencing device.
Fig. 2 is a similar section of a specific mechanically operated silencing device.
Fig. 3 is a cross section of the mechanically operated valve shown in Fig. 2.
Similar letters are used in Fig. 1 and Fig. 2 for similar parts so far as possible.
B is a chamber into which the exhaust gases are led from the engine through the
pipe A. The only means of escape from the chamber B is through the passage or
pipe D which is controlled by a valve or valves as shown.
In Fig. 1a pair of valves H, H¹ are fixed upon a spindle F which is carried in
suitable bearings or guides and is provided at the one end with a funnel-shaped mouth
G and at the other end with a spring F¹ which tends to keep the sliding spindle F
in the position shown.
.
The passage D (Fig. 1) is provided with openings C¹, C into the chamber B and
these openings are so shaped and arranged that the valves H, H' can completely
close them if the spindle F be moved longitudinally in its bearings or guides (from
right to left) against the action of the spring F¹.
The manner in which this automatic device works is as follows:--when, during the
exhaust stroke of the engine, the exhaust gases enter the chamber B they impinge

page_text: upon the funnel mouth G thereby causing the spindle F to slide longitudinally and
to consequently close the openings C¹, C'; the exhaust gases therefore are unable to
escape from the chamber B until their action upon & has ceased and until the
spring F has been able to cause the spindle F to return to its original position; the
valves H, Hare then removed from the openings C¹, C¹ and the gases are enabled
to escape to the atmosphere. The velocity at which the gases escape will be less than
that at which they entered the chamber B owing to their temporary retention. In.
certain cases I prefer to construct the valve H larger than the valve H¹ because the
pressure of the gases in the chamber B then opposes the action of the spring F¹ until
that pressure has subsided to the desired extent; by this means the valves H, H¹
remain closed for a longer period than they otherwise would. It will be understood
that by varying the relative sizes of the valves H, H¹ and the strength of the
spring F¹ I am able to control the period during which the exhaust gases are confined
in the chamber B.
In Figs. 2 and 3 a rotary valve consisting of a disk J mounted on a shaft K in
hearings in a case 1, the disk J having a circular and tapering slot. J¹, controls the
escape of the exhaust gases from the chamber B to a second chamber E through the
pipes C and D; the chamber E may be in open communication with the atmosphere
through a suitable passage E¹ or the passage E' may be provided with a second
controlling valve similar to the one formed by the disk J. The valve shaft K is
provided with a chain-wheel K¹ which is driven by the engine at a constant speed, at
as many revolutions per minute as there are exhaust strokes per minute, and the
relative positions of the disk J to the operations forming the complete cycles of the
engine are such that the disk J during each cycle interrupts free communication
between the pipe C and the pipe D during the periods when the exhaust gases are
entering the chamber B and gradually establishes free communication between them
during the intermediate periods.
It will be understood that I am able to control the period during which the exhaust
gases are confined in the chamber B, as also the rate at which they are allowed to
escape at any given time during the cycle of the engine, by varying the shape of the
slot J.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is :-
(1) In oil, gas or other engines which intermittently discharge exhaust gases the
combination of a chamber into which the gases are discharged and a valve controlling
their escape from the chamber arranged in such a manner that the valve is
automatically closed by the exhaust gases themselves during the periods of discharge
into the chamber and and is allowed to opens between those periods whereby the
velocity at which the exhaust gases escape from the chamber is reduced substantially
for the purpose described.
(2) In oil, gas or other engines an exhaust-gas silencing device substantially as
shown-and described and shown in Fig. 1.
(3.) In oil gas or other engines an exhaust gas silencing device substantially as
described and shown in Figures 2 & 3.
Dated this 9th day of March 1900