Note: Descriptions are shown in the official language in which they were submitted.
2099~36
APPARATU8 AND METHOD FOR VENTING AND FOR MONITORING
OIL LEVEL8 IN MARINE OUTDRIVE8
TECHNICAL FIELD OF THE INVENTION
This invention relates to a novel, improved
- 10 apparatus and to a method for providing a pressure
- equalizing vent and for monitoring the oil level in
marine outdrive units. Devices of that character
are particularly useful for improving the service
life of marine outdrive units. Such devices will
.~ 15 be variously referred to herein as oil reservoir
and monitoring systems, and as vent systems.
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:~ BACKGROUND OF THE INVENTION
` 20
.~ A continuing demand exists for a simple,
inexpensive method and apparatus which can be used
to vent marine outdrive units, and which can also
be used to monitor and insure adequate oil supply
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2~99636
to marine outdrive units. In particular, a needexists for a simple, inexpensive system to enable a
marine outdrive to utilize a pressure equalization
vent to eliminate the slight positive pressure
which occurs by the heating of a marine outdrive
unit during operation, and to eliminate the slight
negative pressure which occurs in a marine outdrive
unit upon cooling after operation. Also, it would
~ be desirable for a boat operator to be able to
- 10 visually check the outdrive oil system to be sure
that (a) sufficient oil is in the system, and (b)
that the oil is of the desired quality, and has not
become contaminated or emulsified by water or other
foreign substance.
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,~ The need for such devices is commonly seen in
conjunction with the use of marine outdrive units,
where it is desirable to (a) prevent corrosive
saline water from being sucked into a cooling
outdrive unit after the use of same, and (b) to
conveniently monitor the oil level while the unit
is operating. Currently, it is difficult or
impossible to monitor the oil level in marine
; outdrives while operating the unit. As a result,
`~` 25 there are concomitant adverse effects on outdrive
service life and on outdrive unit maintenance
costs.
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For example, I have inadvertently damaged
several outdrive units on a commercial fishing boat
that I own by catching trolling wire in the prop
and ruining the seal around the output shaft. In
systems such as those manufactured by Volvo and
some other manufacturers, there is no way to check
the oil level for so long as the outdrive unit is
in the water. Thus, I had no warning that the oil
level was running low, and did not discover the
loss of oil from the outdrive gear system until
after operation had occurred without benefit of
lubrication. Consequently, expensive repairs were
necessary.
It should also be noted that a failure of
; critical outdrive unit seals can also be the result
of normal wear and tear, or by operating for
" extended periods of time with dirty oil (for
example, contaminated with metal flakes), or by
striking submerged objects with the prop. In a few
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cases, oil may be lost immediately and the danger
created of unit operation without lubrication.
2a~l3636
Most outdrive units have oil levels which do
not completely fill the upper shell of the
outdrive, so as to allow for expansion of the oil
during operation. In some models, a gimble bearing
which supports the upper gear set is located above
the normal oil level, and is lubricated by splash
from gears during operation. Even if no immediate
problem occurs due to the aforementioned damage to
seals, when the outdrive cools after normal
operation, the vapor space in the top of most
outdrive units tends to create a vacuum, which
draws saline waters into the outdrive unit through
any damaged or leaky seals. Thereafter, once the
unit cools, loss of oil may occur through leaky
seals. Thus, many outdrive units are damaged
- while sitting in the marina between periods of
service.
Another condition adverse to extended outdrive
unit service life is that cooling of moist air
within the outdrive vapor space causes condensation
to form within the cap and on the upper gear set
bearing. The ensuing rust may cause premature
failure of the bearing, and contributes to wear
rates and reduced service life of the gears and the
; seals.
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2099636
In addition, since most factory built outdrive
systems lack a vent system, outdrive units have a
moderate amount of internal pressure build-up due
to oil expansion caused by higher oil temperatures
which are experienced during high speed operations.
This tends to force oil outward through the oil
seals which seal oil in and water out, and such
leakage may occur through damaged or weak seals.
, 10
Another common deficiency of the heretofore
available oil systems for outdrive units is the
absence of a readily apparent visual indication to
the operator that an adequate supply of suitable
oil is available to the outdrive unit. The
advantage which would be provided by such an
indication is important and self-evident.
2099636
SUMMARY OF THE INVENTION
I have now invented, and disclose herein, a
novel, improved method and apparatus for venting
i and for the supply and monitoring of oil in marine
outdrive systems. My apparatus and method does not
have the above-discussed drawbacks common to those
heretofore used outdrive oil supply systems of
which I am aware. Unlike oil supply systems
heretofore available, my system is simple, compact,
relatively inexpensive, light, and easy to install,
~,
yet provides a needed vent function and visual
monitoring method for oil supply. The apparatus
makes it easy to monitor and to add oil and is
otherwise superior to the heretofore available
systems of which I am aware.
My novel method and apparatus for venting,
~ 20 monitoring, and supplying oil to outdrive units
;` differs from those systems commonly available in
:
one respect in that my system has a simple oil
monitoring reservoir suitable for locating inside
the boat, which can be observed for an indication
of oil level, in addition to audible and visual
warning systems, and to which oil can be added
during operation, as necessary.
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2099636
I have now developed a venting, oil level
monitoring and oil addition apparatus for use in
combination with a marine outdrive for facilitating
the constant supply of lubricating oil to the
' outdrive unit, so as to inhibit the deterioration
~; of the outdrive system. The venting, oil addition,
` and monitoring apparatus may be used with the type
of marine propulsion system having an engine
integrally connected to an outdrive. The apparatus
includes an oil reservoir having an upper vent
` connection, and a conduit suitable for allowing the
passage of oil between the outdrive unit and the
oil reservoir. Additional features include the
indication of a normal and low operating oil level
indicators at the oil reservoir. Also, automatic
electronic oil level monitoring and excess metal
detection devices may be advantageously connected
;; at the oil reservoir. In addition, suitabIe
hardware, such as flexible braided stainless steel
covered hose and suitable quick connect fittings,
provide the necèssary conduit connection means
between the oil reservoir inside a boat and a
variably positioned outdrive at the stern of the
boat.
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2099636
My apparatus, which I have called a "Unit
Saver" because of its ability to save and extend
the life of an outdrive unit, alleviates the slow,
tedious job of filling an outdrive unit such as the
Volvo brand design. In Volvo's design,
approximately three and one-half (3 1/2) quarts of
~` oil must be fed slowly into the unit through adipstick hole, which may be only one quarter (1/4)
inch or three eighths (3/8) inch in diameter. The
need for a convenient method of pouring oil into an
outdrive unit is shared by all outdrive unit owners
during both oil changes and when adding makeup oil.
In contrast, the clear plastic oil reservoir of my
apparatus is designed with at least a one inch (1")
diameter fill hole and typically one (1) quart or
r~
more capacity, so that an entire quart of oil can
` be quickly added to the system at one time.
. :
Other embodiments of my apparatus and method
2 O provide further variations in routing of the vent
and oil line to the outdrive unit.
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20~9~36
.
; Aside from the foregoing, my novel apparatus
is simple, durable, and relatively inexpensive to
manufacture. My apparatus and method for venting,
monitoring oil levels, and for adding oil in
outdrives is a substantial improvement over the
previous apparatus and methods methods known to me.
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OBJECTS, ADVANTAGES, AND FEATURES OF THE INVENTION
", 10
From the foregoing, it will be apparent to the
reader that one important and primary object of the
~ present invention resides in the provision of a
- novel, improved method and apparatus to provide a
- 15 means for both venting and for maintaining an
-~ adequate operating oil level in marine outdrive
;~ units, thereby preventing or reducing corrosion
damage and lubrication failures to such outdrive
units.
Other important but more specific objects of
the invention reside in the provision of venting
and oil monitoring systems as described in the
preceding paragraph which:
2~99~6
: enable an outdrive unit to operate at
atmospheric pressure within the unit,
by providing a suitable pressure
. equalizing vent to the atmosphere to
accommodate the expansion and
contraction which occurs due to heating
and cooling of the outdrive unit;
. allow the addition of oil to an
outdrive unit to be done in a simple,
one step manner;
. .
allow the monitoring of oil levels in
- an outdrive unit from inside the boat;
allow the monitoring of oil levels in
an outdrive unit even during unit
operation;
:, .
in conjunction with the preceding
object, have the advantage that they
can ~be installed in a convenient
location for easy access during boat
` operations;
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2099~36
provide by simple observation an
indication to the operator of the oil
level and oil condition, while the boat
. is operated;
.. 5
are relatively inexpensive;
,
. are relatively simple to install;
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are relatively compact and thereby
require little space;
'~
' allow operation of outdrive units with
fully oil flooded, zero headspace
covers;
-
prevent the intake of saline waters to
outdrive units to thereby prevent
corrosion damage to critical
components.
Other impo.rtant objects, features, and
additional advantages of my invention will become
apparent to the reader from the foregoing and the
appended claims and as the ensuing detailed
description and discussion proceeds in conjunction
with the accompanying drawing.
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2~99~t~
BRIEF DESCRIPTION OF THE DR~WING
In the drawing:
Figure 1 is a perspective view of a prior art
marine outdrive unit, illustrating the typical
operating configuration.
Figure 2 is a vertical cross sectional view of
a transom a boat showing installed a first
embodiment of a venting and oil level monitoring
and addition system constructed in accordance with
the teachings of the present invention.
Figure 2A is a vertical cross sectional view
of a transom a boat showing installed a second
embodiment of the venting and oil level monitoring
and addition system constructed in accordance with
the teachings of the present invention.
Figure 3 is a perspective of the oil reservoir
portion of the present invention.
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2~96~6
Figure 4 is a vertical cross sectional view of
an oil reservoir constructed in accord with the
teachings of the present invention.
Figure 5 is a vertical cross sectional view of
the transom of a boat showing one method of
passing the oil line of the present invention
through the transom.
Figure 6 is a side view of the oil passage
nozzle installed in the outdrive unit housing to
allow oil to communicate with the external oil
reservoir.
In so far as possible, like reference numbers
are used to indicate like parts throughout the
several figures; similar parts may be indicated
without additional description by use of a "prime"
suffix where similar parts are used in slightly
different configurations or locations.
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209~6~6
. DETAILED DESCRIPTION OF THE INVENTION
,~
Attention is now directed to Figure 1, where
the transom 10 of a boat (not shown) has attached
~: 5 thereto an outdrive unit 12 with a typical factory
provided prior art oil system. In the unit 12,
the head 14 is filled with oil 16 to a level L
-~ whlch may fluctuate upward or downward within head
14 of outdrive unit 12, depending upon the amount
of oil 16 placed in the unit 12 oil system, and
: upon the operating temperature of the oil 16. It
should be noted that unit 12 is normally below
: water line W while the boat is in the water,
making it difficult or impossible to access
15 dipstick 18 to determine the actual operating oil
14 level L.
~ To avoid passage of water into the head 14 of
outdrive unit 12, the a seal 20 is provided on the
underside of dipstick 18, to seal it against the
cap 22 of head 14. However, air and water vapor in
space 24 above the oil level L in head 14 may
expand as unit 12 heats during operation. Without
venting, pressure inevitably builds up against
~ 25 seal 20, as well as lower shaft seal 26, thus
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: 2099636
causing oil 16 to tend to escape outward into the
water. More damaging, as the unit 12 cools after
use, water may be draw into the unit 12 through
seals 20 and 26.
; 5
; Turning now to Figure 2, one embodiment of the
oil supply and monitoring apparatus 30 is shown
connected to an outdrive unit 32. The basic parts
of the oil supply and monitoring apparatus 30 are
a reservoir 34 and an oil line 36. The oil line
36 allows communication of oil 38 (see Fig. 4;
shown at level U there and in the oil reservoir 34
of this Fig. 2) between the upper reaches 40 of
outdrive unit 32 and the reservoir 34.
Oil line 36 includes various features which
enable passage of oil through the transom 42 and
on to the variably positioned outdrive 32. A
first end 44 of a first oil line segment 36a is
connected to oil reservoir 34 at outlet fitting
48. The second end 49 of first oil line segment
36a is connected to an interior portion 50 of
bulkhead fitting 52. Bulkhead fitting 52 provides
; an annular passageway, thus allowing oil 38 to
pass therethrough. The bulkhead fitting is
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2099536
normally affixed to transom 42 via way of interior
54 and exterior 56 compression nuts, each of which
has a gasket 58 between the nut and transom 42.
To facilitate directing the second oil line
segment 36b toward the outdrive unit 32, I have
found it convenient to provide a 45 elbow 62 to
direct downward the flow of oil 38 toward outdrive
32 as it exits bulkhead fitting 52. For
convenience, a swiveling quick coupling connection
assembly 64 having a female end 56 and male end 58
may be utilized to enable easy hookup and removal
of first end 70 of second oil line segment 36b
from outdrive 32. Further details of this feature
are illustrated in Figure 5 below.
The second end 72 of second oil line segment
36b enters the outdrive unit 32 through an oil
passage adaptor 74. The adaptor 74 may be
advantageously sized to fit an existing dipstick
~ 18 passageway 75 in those outdrive units which
;~ have such as feature (see Figure 1, for example).
Alternately a convenient and suitably sized
opening 76 in the upper housing 78 of the outdrive
22 may be provided by any convenient method, such
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2099~36
as here shown to connect the alternate oil line
36b' to alternate oil passage adaptor 74', here
shown at the back 77 of outdrive 32.
Oil reservoir 34 may be attached to transom 42
by any convenient method, such as by way of
; fasteners 78 that penetrate the transom 42.
Preferably, oil reservoir 34 is located at a
suitable height H above the upper housing 78 of
outdrive unit 32 so as to enable convenient
gravity flow of oil from the reservoir 34 to
outdrive 32. I have found that a height H of
twelve (12) inches to twenty four (24) inches is
normally adequate to provide the desired effect.
Such positioning eliminates the need for
mechanical oil recirculation systems, thus
avoiding an additional risk of oil system failure.
Turning now to Figure 2A, an alternate
embodiment of my apparatus 80 to provide venting
and enhanced lubrication protection to marine
outdrives is illustrated. Here, the need for
additional thru-hull fittings is avoided by (i)
running the oil line 36b'' through the transom 42
within the rubber boot 81 provided for the drive
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2099636
shaft 82, as well as through a portion of shaft
seal 83' and into outdrive unit 32' at oil adaptor
fitting 74'', and (ii) using suitable screws or
other fasteners 84 to attach oil reservoir 34 to
5the interior 86 of transom 32. Note that oil line
36a ends at a bell housing 87 at the rear of
engine 88, but otherwise the arrangement is
similar to that first shown in Fig. 2 above.
.; ,
10Attention is now directed to Figures 3 and 4,
where details of the oil reservoir 34 are shown.
The reservoir 34 is preferably provided in a clear
; plastic material, which enables the user to see
through the wall 91 of plastic reservoir 34 to
15observe the oil level U through observation port
92 which is defined by edges 93 which provide an
opening in attachment strap 94. Also, oil 38 can
be seen in the clear upper portion 96 and lower
portion 98 of the reservoir 34.
An important advantage of the clear plastic
oil reservoir 34 is the access for viewing both
the oil level U and the quality of the oil. If
the oil 38 and salt water mix, the oil turns a
25milky white color. If gear wear is excessive the
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2099636
oil will turn silver from metal flakes. Also, the
oil color will turn quite dark after a period of
normal wear, signaling that an oil change is due.
An atmospheric breather vent 100 is provided
to allow heated vapors V to escape outward as
heated oil 38 expands, and to allow air V' to
enter when the oil system cools after operation.
A fill port 101 is provided, which is normally
closed via oil plug 102. This is important
because in the usual outdrive unit, only a small
oil fill port is provided, which takes great care
and an inordinate amount of time to add oil,
whereas this oil fill port 101 is of sufficient
diameter D to allow quick addition of oil, for
example in convenient quart containers.
Turning now to Figure 4, the visual and
audible oil level alarm and monitoring devices are
shown. The need for a visual and audible oil
level monitoring system is especially important
when operating boats from an interior cabin or a
flying bridge. My system incorporates two types
of alarm systems, and normally locates the sensing
devices in the clear plastic oil reservoir 34. A
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2099~36
detector 110 is provided for an oil low level
alarm system indicator which may be located where
convenient. When oil level U drops to a position
at the level indicator detector 110, a signal is
sent to the audible 112 and visible 114 alarm
signal devices. One simple way to accomplish this
is by use of a commercially available Kysor brand
' five (5) post warning module and wiring harness.
,: ~
The need for metal detection is accomplished
in one of two ways, either by visual checking of
:.
the magnetic drain plug 120 or with a special
aircraft metal detector sending unit 126, which
activates a visual 132 and audible 134 alarm
system. For simplicity and low cost, the o~l
reservoir 34 is designed to use standard pipe
plugs in place of either the magnetic drain plug
120 or the aircraft metal detector sending unit
126. The metal detector sending unit 126 is
activated by bridging of two magnetic contracts in
the sending unit by metal particles in the oil.
When this occurs, audible 134 and visual 132
alarms are set off, thus alerting the operator to
an abnormal wear condition.
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2~9963~
In Figure 5, the thru transom fitting 52 is
shown in detail, along with a combination quick
coupler disconnect. The thru transom fitting 52
is commonly fabricated out of a five eights (5/8)
inch by two (2) inch length of stainless steel or
brass round stock, drilled full length with at
least a one eighth (1/8) inch bore, and tapped
with one eighth (1/8) inch pipe threads inside.
The outside is normally provided with five eighths
(5/8) inch national coarse thread grade to receive
, the aforementioned compression nuts 54 and 56.
To allow for easy oil line 36b removal,and for
allowing swivel in the oil line 36b for up and
down as well as sideways steering and trim of the
; outdrive unit 32, a stainless steel swivel quick
coupler assembly 64 is provided. As briefly
described above, this assembly is mounted around
;~ an annular bulkhead fitting 52 which allows oil 38
to pass therethrough.
The bulkhead fitting is normally attached to
transom 42 via way of interior 54 and exterior 56
compression nuts, each of which has a gasket 58
between the nut and transom 42.
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20996~6
To facilitate directing the second oil line
segment 36b toward the outdrive unit 32, it is
convenient to provide a 45 elbow 62 to direct the
flow of oil 38 toward outdrive 32 as it exits
bulkhead fitting 52. The swiveling ~uick coupling
connection assembly 64 having a female end 66 and
male end 68 may be utilized to enable easy hookup
and removal of first end 70 of second oil line
segment 36b to outdrive 32.
Figure 6 shows the oil inlet fitting 74 which
is provided at the outdrive unit 32 to allow entry
of oil to the outdrive unit 32 through annular
opening 148. The fitting normally includes a
hexhead 150 and an o-ring 152 to securely affix
the fitting to outdrive unit 32 via screwing
threads 154 into complimentary threads in opening
76 in outdrive 32.
The invention may be embodied in other
, specific forms without departing from the spirit
or essential characteristics thereof. The present
embodiments are therefore to be considered in all
respects as illustrative and not restrictive, the
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2~9~36
scope of the invention being indicated by the
appended claims rather than by the foregoing
description; and all changes which come within the
meaning and range of equivalences of the claims
are therefore intended to be embraced therein.
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