[0001] THIS INVENTION relates to adaptation of an internal combustion engine to permit restarting
of the engine as soon as possible after the carburettor chambers have been flooded
with water.
[0002] An internal-combustion engine for a land vehicle is normally not designed in any
way for contact with, or immersion in,a body of water. Should such immersion occur
as the result of an accident the engine stops,becomes flooded with water, and needs
specialist attention thereafter.
[0003] A few vehicles have on-land/in-water capability. e.g. tanks. They typically have
fully shielded engines, with sealed housings and special exhaust and inlet ports.
This is an expensive expedient, and for waterborne craft attempts have been made to
protect the engines especially outboard engines against casual splashes, temporary
immersion (wave action) or longterm immersion (e.g. capsize) by a selectively sealable
carburettor air intake. Moreover. our copending Patent Application 8524232 of even
date entitled "INTERNAL COMBUSTION ENGINE AIR IKTAKE" proposes a further modification
in which the air intake is extended by an elongate duct the configuration of which
and/or the air inlet location of which and/or the nature of the air inlet end of which
is such as to protect the carburettor against flooding by water during partial or
total immersion of the motor.
[0004] All of the above expedients set out to prevent access of water to the interior of
the engine,and especially to the carburettor. However, we have realised that, especially
for a smaller engine, the cost of even the cheapest expedient can be relatively significant.
[0005] The present invention therefore sets out to achieve a different end, namely, means
by which a engine flooded with water can be rapidly cleared and restarted. It has
particular utility in, but is not limited to, the smaller end of the range of outboard
motor sizes.
[0006] The present invention envisages an attachment to a conventional carburettor. Typically,
these define a chamber to hold a quantity of petrol. At the base of the chamber is
a threaded port with a threaded sealing plug therein. Even some land vehicles possess
such carburettor drain ports, for instance for use in the event of water in the fuel
or similar mishaps. Outboard motors possess such carburettor drain ports for use more
typically when water has entered the carburettor via contaminated fuel in the air
intake duct.
[0007] It is not unknown for craft fitted with such motors to capsize e.g. on a rescue or
assault mission in adverse weather. The vessel is designed (or provided with) a self
righting capability but by the time this has come into use the motor is typically
full of water, even though mercury gravity switches switch off the motor after a given
angle of capsize.It is difficult in adverse weather, often at night, to remove the
engine housing, locate and remove the drain port plugs (especially since these are
usually locate" in the expection that the engine will be back on the bench at the
repair shop before such steps are taken and are therefore not easily accessible )
and drain the small carburettor chamber effectively, in heavy seas with waves splashing
the stationary craft.
[0008] In one aspect the invention provides a carburettor for an internal combustion engine
of the type with a carburettor body chamber with an air intake at or towards the top
and a drain port at the bottom characterised in that the drain port is permanently
open and communicates with a downwardly extending length of drainage ducting incorporating
a manually operable externally accessible normally closed but selectively operable
closure means located beneath and spaced from the drain port to define a length of
ducting between the closure means and the open drain port which at least partially
fills with liquid fuel when the engine is running; whereby, in the event of water
ingress through the air intake, opening of the closure means allows drainage under
gravity of the fuel accumulated in the drainage duct and thus of the carburettor contents.
[0009] The drainable ducting is preferably a flexible synthetic polymer tube, controlled
by a turnable knob as a tap to achieve drainage, preferably at least in part assisted
by the fuel existing in the tube. A drainage end can be located lower than the turnable
knob, to further facilitate drainage.
[0010] An internal combustion engine comprising one or more carburettors modified as above
is also an aspect of the present invention. Such an engine can be an outboard motor
engine; any control means e.g.knobs, can be mounted on the fascia in an accessible
forward position.
[0011] The invention will be further described with reference to the single Figure of the
accompanying drawing, which shows a modified single carburettor system and its location
in relation to an outboard motor.
[0012] An outboard motor comprises a tray 1 upon which is mounted a motor 2 shown diagrammatically
as block (in dotted lines) with a starter pulley 3 (and cord 4) on top.Beneath and
integral with tray 1 is a rudder
5 enclosing a drive between the motor 2 and the propeller 6. A lid or housing 7 fits
over the motor, and onto the tray 1 generally by simple clips.
[0013] At the forward end of the motor is located a carburettor 8 air intake generally at
an upper location 8a and with a conventional drain port 9 at its lower end. However,
in place of a threaded fitting there is fixed a flexible polymer tube 10, passing
to control knob 11 suitably positioned on fascia board 12 of tray 1. The knob 11 is
generally below the level of drain port 9, and the outlet from the drain port at 13
is lower still.
[0014] Instead of the one carburettor shown, two, three, four or more carburettors can be
used, each equipped with a suitable drainage length of tubing 10. Separate knobs 11
can be used in such a case, or the drain tube can be combined to only one or two such
knobs for joint drainage.
[0015] The use of such a fitment is as
'follows:-Initially the engine 1 is running normally. As the craft (e.g. an inflatable
dinghy) capsizes, the engine stops due to a cutout switch based on gravity flow of
mercury in a constricted container. The vessel is righted, in itself a standard emergency
procedure . The lid or cowling 7 is removed, and excess water drains away.The fuel
line is removed, and knob 11 is unscrewed. It is of course readily accessible to the
operator and does not need tools for its use. Moreover, we have found that the length
of tubing 10 above the knob 11 fills with petrol in use: thus, when the knob 11 is
opened this length of full tubing drains and draws out the liquid from the carburettor.
This "siphon" effect is more efficient for emptying the carburretor chamber than simple
drainage through a drain port, and is effected without inconvenient removal of threaded
drain port plugs.
[0016] The engine spark plugs are then removed, and the engine turned over by pulling cord
4. This expels water from the engine cylinders through the spark plug openings. 20
pulls or so may be necessary.
[0017] The fuel line is reconnected to flush the carburettors, the fuel use being drained
through tube 10 until no water remains therein. The fuel valves are closed, the engine
primed, choke pulled out, new dry plugs fitted. and the engine should restart.
1. A carburettor for an internal combustion engine of the type with a carburettor
body chamber (8) with an air intake (8a) at or towards the top and a drain port (9)
at the bottom characterised in the drain port is permanently open and communicates
with a downwardly extending length of drainage ducting (10) incorporating a manually
operable externally accessible normally closed but selectively operable closure means
(11) located beneath and spaced from the drain port (10) to define a length of ducting
between the closure means and the open drain port which at least partially fills with
liquid fuel when the engine is running; whereby, in the event of water ingress through
the air intake, opening of the closure means allows drainage under gravity of the
fuel accumulated in the drainage duct and thus of the carburettor contents.
2. A carburettor as claimed in claim 1 characterised in that the drainage ducting
is a flexible synthetic polymeric tube (10) and the closure means is a turnable knob
(11) selectively operable to open or close the tube.
3. A carburettor as claimed in claim 2 characterised in that the polymeric tube has
a drainage end (13) located lower than the turnable knob.
4. An internal combustion engine (2) characterised in that it comprises one or more
carburettors as claimed in claim 1, 2 or 3.
5. An internal combustion engine as claimed in claim 4 characterised in that it is
constituted as a marine outboard engine (2) with turnable closure means for the duct
mounted on a fascia member (12) of said engine (2) so as to be located in an accessible
position from the vessel.