US1785089A

US1785089A - Underwater exhaust mechanism

Info

Publication number: US1785089A
Application number: US426249A
Authority: US
Inventors: Finn T Irgens
Original assignee: Outboard Motor Corp
Current assignee: Outboard Motor Corp
Priority date: 1930-02-06
Filing date: 1930-02-06
Publication date: 1930-12-16
Anticipated expiration: 1947-12-16

Description

Patented Dec. 16, 1930 UNITED STATES PATENT OFFICE FINN T. IRGENS, 0F MILWAUKEE, WISCONSIN, ASSIGNOR TO OUTBOARD MOTORS COR- PORATION, 0F MILWAUKEE, WISCONSIN, A CORPORATION OF MICHIGAN UNDERWATER EXHAUST MECHANISM Application filed Rbruary 6, 1930. Serial' No, 426,249.

This invention relates to improvements .in under water exhaust mechanism, with par ticular reference to outboard motors.

It is the primary obj ect of the inventionto provide an automatic cutout for under water exhausts including. a by-pass port for permitting the exhaust to ass directly into open Y air when the engine 1s started, and means for automatically sealing said port when the under water exhaust passages are freedv of water by operation of the boat. It is my pur-V pose to accomplish these results with no moving parts and without the use of valves or like mechanisms by establishing a Water seal for the by-pass port which is rendered eiective by the same means which frees the under v water exhaust passages of water.

In th drawings:

Figur 1 shows a conventional type vof outboard motor in side elevation, the lower unit of such motor and the exhaust passages being shown in vertical axial section. f

Figure 2 is afragmentary detail, in front elevation, of av portion of the exhaust manifold shown independently vof the water conduits applied thereto in Figure 1, andA partially broken away to expose its interior construction. l

Figui-e 3 is a detail view taken in the plane' ence characters throughout the several views.

The outboard motor herein illustrated is of conventional design with the exception of the waterseal feature hereinafter to be described. It includes an engine having cylinders, of which one is shown at 6, exhausting into a manifold passage .7. The engine operates the usual'drive shaft 8 by which motion is transmitted through the bevelled gearing 9 to a hollow propeller sha-ft 10, carrying a l propeller 11 having ports '12 in its blades -cmmunicatingwith the interior of the hol-` low shaft.

The cooling system for the engine is of a RUSS-UEE) leads to-chamber 20 in the lower unit which communicates through a duct 21 and the ported plug 22 with the front end of the hollow propel er shaft 10 through which water is exhausted centrifugally by the radialpassages in the blades of propeller 11.

The water circulation system has been`de` scribed briefly in order to bring out the fact that the water seal herein referred to is established by means entirely independent of the cooling system. The exhaust connections and the means for supplying the water seal for the by-pass ports therein will no.w bedescribed.. I

The exhaust manifold 7 leads through conduit 2A to thechamber 25 in the lower unit which has an outlet at 26 in the form of a flat yrearwardly extending tube, the delivery end of which Ais preferably located beyond the propeller 11. The water passing such tube during operation of the outboard motorinbo'atlpropulsion has an aspirating effect which withdraws the gases from the manifold substantially as rapidly as such gases arrive in the manifold from the engine cylinders. The effect of this withdrawal of exhaust gases from the manifold not only eliminates back pressure therein but actually leaves the interior of the manifold substantially at atmospheric pressure. This condition is obtained, however, only fwhen the de; vice is operating substantially at the full speed for which it is designed. At 'lesser speeds there is a lesser aspirating effect at the discharge orifice in the flattened tube 26.

When the engine is started with the motor atrest the chamber 25 will containwater to a depth considerably in excess -of that indicated by the water line shown inv Figure 1, .which is the approximate water line during full speed operation on a planing boat. This water will oppose any delivery of exhaust gases through the port at 26. In order to avoid excessive back pressure it is desirable to provide means for exhausting gases directly into the atmosphere and for that purpose I have provided by-pass ports 28 which open into-a pipe 29 which communicates at 30 with the atmosphere. A deilector 3l is preferably associated with port 30 in order to direct downwardly fluids issuing from such port. e

For the purpose of sealing ports 28 after the normal under water exhaust passage is opened, as when the outboard motor is operating at full speed in boat propulsion, I provide a means independent of the engine cooling system for filling pipe 29 with water, thereby cutting ofil communication between ports 28 and port 30. This may be done in numerous ways, one of which involves the provision of partition 16 in the lower unit to form therein a passage 32 opening forwardly through a mouth 33 and communicating around bushing 34 with a duct at 35 opening at 36 through the wall of conduit 24 and pipe 29 into the interior of such pipe.

The only force acting to deliver water through the system of passages just described is the movement of the outboard motor through a body of water which establishes pressure at mouth 33 and tends to evacuate water through the delivery port 26 of the under water exhaust. Both the pressure established in chamber 32 and the depression established in chamber 25 will be, in general, proportioned to the rate of operation of the motor and hence it is easily possible to locate

ports

28 and 30 at such a height that communication therebetween will be sealed by the rise of water in pipe 29 at approximately the same time that the under water exhaust through the flattened tube 26 becomes effective.

In order to keep the pipe 29 full of water during normal motor operation, the amount of water supplied to the pipe is preferably such that some of the water will flow through port 30. Under such circumstances, some of it vmay also flow through t'" ports 28, but this is immaterial since the amount of such water will be small and therefore will not destroy theeii'ective sealing of such ports. The pressure conditions existing in thev exhaust manifold during full operation of the Y motor will not encourage a loss of sealing water therein and such loss is reduced also bythe fact that openings 28 are small in diameter, while the combined area is effective for by-passing gases, and resistance to flow of a liquid is greater than would be the case if a single port of like area were used. It is particularly to be noted that no loss of Water through ports 28 can affect in any way the cooling system for the Amotoresince the sourceof such water is `entirely independent of the cooling system. It is also to systemF of which be noted that there are no moving parts such as might become stuck, no valves being used.

1. The combination with a marine engine having an exhaust manifold, with a submersible outlet and an atmospheric by-pass, of means for establishing a liquid seal for said by-pass.

2. The combination with a marine engine having an exhaust manifold, with a submersible outlet and an atmospheric by-pass, of means for establishing a liquid seal for said by-pass, and means for freeing said submersible outlet of water accumulated there in, both of said means being dependent for their operation upon movement through a body of water, whereby said seal will be established as said outlet is freed of water.

3. In an outboard motor, the combination with an engine having a by-passing exhaust manifold and a lower, unit provided with an under water outlet for said manifold, said lower unitl being provided with a forwardly disposed opening, and a well communicating with said opening and extending across the by-pass of said manifold whereby water admitted through said opening as said outboard motor is in movement at a predetermined rate will fill said .well to the point of sealing said by-pass.

4. In an outboard motor, the combination with an engine having an exhaust manifold provided with a by'pass including a well having exhaust gas inlet and outlet openings, 'of a lower unit provided with a submersible outlet with which said manifold is in communication, and a submersible water i t communicating' with said well and opening in a direction to receive water in the movement of said lower Zunit, whereby, at a predetermined rate of movement of said lower unit, to elevate water into said well to a depth sufficient to cover one of said openings to seal said by-pass.

5. In an outboard motor, the combination' with an engine having an exhaust 'manifold vprovided with a by-pass including a Well having exhaust gas mlet and outlet openings, of a lower unit provided with a submersible outlet with which said manifold is in communication, and aV submersible water inlet communicating with said well Vand opening ina direction to receive water in the movement of said lower unit, whereby, at a predetermined rate of movementl of said lower unit, to elevate water into said well to a depth suihcient to cover one of said openings to seal said by-pass, said lower unit being provided with a cooling said duetis entirely independent.

6. In an outboard motor, the combination Withan engine having an exhaust manifold provlded wlth a submersible outlet and a by-pass duct to open air above water, of a lower unit for said engine including a cooling system conduit therefor and a forwardly opening duct independent'of said conduit and adapted in the movement of said 't tov 5 receive water, said duct lbeing extended across the by-pass of said manifold whereby water rising in said duct will act as -a seal for said by-pass.

` 7. In an outboard motor, the combination 10 with an .engine having an exhaust manifold ported above the water level and yprovidedwith an outlet therebeneath in a rearward direction, whereby movement of the motor through `the water will tend to exhaust gas l5 from said manifold, of a forwardly disposed `water inlet and a conduit connected with said inlet, extendin across the port of said manifold and vopening 4to discharge water outside of said manifold. o 8. In an outboard motor, the combination with an engine having an exhaust manifold ported abovev the water. level and provided with an outlet therebeneath in la rearward direction, -whereby movement of the motor 5 through the water will tend to exhaust gas from said manifold, of a forwardly disposed water inlet and a conduit connected with said inlet, extending `across the port of vsaid manifold and opening to discharge water lo outside of said manifold, vsaid "conduit in- ;llding a well disposed within said mani- 9. In an outboard motor, the combination with an engine having an exhaust manifold :s` ported above the water level and provided with an outlet .therebeneath in a rearward direction, whereby movement of the motor throughy the water will tend to exhaust gas from 'said manifold, of a forwardly dis- 0 Iposed waterinlet and aconduit connected with said inlet, extending across the port A of said manifold and opening to, discharge 'water outside of said manifold, and a lower unit connected with 'said engine and in which 5 the opening of said duct is formed, said unit being provided with 'a cooling duct leading to said engine and of which said first mentioned duct is independent. v I 10. In an outboard motor adapted to be u partly submerged to a. predetermined water i line, the combination with an en nehaving an exhaust manifold provided wlth an outv let below said water line and an atmosheric by-pass therefor above said `water s ine, of a cooling system for ,said engine, a duct independent of said 'cooling system having an inlet below said' water line and l intercepting said b -pass at a level above said water line, an .means effective in the operation of a motor for establishing a head o water in said duct above said level, whereby to provide a liguid seal for said by-pass lin the opgration o said motor.

FINN T. IRGENS.