U.S. patent application number 11/895106 was filed with the patent office on 2009-02-26 for propulsion system for a ship or seagoing vessel.
Invention is credited to James Hagan.
Application Number | 20090053944 11/895106 |
Document ID | / |
Family ID | 40382607 |
Filed Date | 2009-02-26 |
United States Patent
Application |
20090053944 |
Kind Code |
A1 |
Hagan; James |
February 26, 2009 |
PROPULSION SYSTEM FOR A SHIP OR SEAGOING VESSEL
Abstract
A marine drive is engaged with and is driven by a vessel's
engine drive shaft. The drive includes: a universal joint secured
to the vessel's hull; a first screw shaft supporting a first screw;
a first gear set driven by the first screw shaft; a second screw
shaft driven by the first gear set; a second gear set driven by the
second screw shaft; a third screw shaft driven by the second gear
set and supporting a second screw; and a third screw supported by
the second screw shaft at its terminal end. The first and second
gear sets are enclosed within a water-tight enclosure enabling
rotational speed differentiation between the first and second screw
shafts and enabling rotational sense reversal between the second
and third screw shafts. An actuator provides changes in angle of
attack of the second and third screws.
Inventors: |
Hagan; James; (Fountain
Valley, CA) |
Correspondence
Address: |
PATENT LAW & VENTURE GROUP
2424 S.E. BRISTOL, SUITE 300
NEWPORT BEACH
CA
92660
US
|
Family ID: |
40382607 |
Appl. No.: |
11/895106 |
Filed: |
August 23, 2007 |
Current U.S.
Class: |
440/75 |
Current CPC
Class: |
B63B 3/42 20130101; B63H
5/125 20130101; B63H 23/02 20130101; B63H 2005/106 20130101; B63H
5/10 20130101 |
Class at
Publication: |
440/75 |
International
Class: |
B63H 23/00 20060101
B63H023/00 |
Claims
1. A marine drive apparatus adapted for being engaged with and
driven by an engine drive shaft penetrating the hull of a vessel,
the apparatus comprising and mutually engaged in a sequence of: a
universal joint adapted to be secured to the hull; a first screw
shaft supporting a first screw; a first gear set driven by the
first screw shaft; a second screw shaft driven by the first gear
set; a second gear set driven by the second screw shaft; a third
screw shaft driven by the second gear set and supporting a third
screw; and a second screw supported by the second screw shaft at a
terminal end thereof; the first and second gear sets enclosed
within a water-tight enclosure; the first gear set enabling
rotational speed differentiation between the first and second screw
shafts; the second gear set enabling rotational sense reversal
between the second and third screw shafts; the apparatus further
comprising an actuator engaged with the enclosure and adapted for
securement to the hull, the actuator positioned and adapted for
changing an angle of attack of the first, second and third
screws.
2. The apparatus of claim 1 wherein the first gear set comprises a
first, second, third and fourth gears in mutual rotational
engagement, the first gear driven by the first screw shaft, the
first and fourth gears rotating coaxially at differential
rotational speeds.
3. The apparatus of claim 2 wherein the second gear set comprises a
fifth, sixth and seventh gears in mutual rotational engagement, the
fifth gear driven by the fourth gear, the fifth and seventh gears
rotating coaxially in opposing rotational senses.
4. A marine drive apparatus adapted for being engaged with and
driven by an engine drive shaft penetrating the hull of a vessel,
the apparatus comprising and mutually engaged in a sequence of: a
first universal joint adapted for securement to the hull; a first
screw shaft supporting a first screw; a second universal joint
driven by the first screw shaft; a first gear set driven by a shaft
of the second universal joint; a second screw shaft driven by the
first gear set; a second gear set driven by the second screw shaft;
a third screw shaft driven by the second gear set and supporting a
third screw; and a second screw supported by the second screw shaft
at a terminal end thereof; the first and second gear sets enclosed
within a water-tight enclosure; the first gear set enabling
rotational speed differentiation between the first and second screw
shafts; the second gear set enabling rotational sense reversal of
the third screw shaft relative to the second screw shaft; and the
apparatus further comprising an actuator engaged with the enclosure
and adapted for securement to the hull, the actuator positioned and
adapted for changing an angle of attack of the second and third
screws.
5. The apparatus of claim 4 wherein the first gear set comprises a
first, second, third and fourth gears in mutual rotational
engagement, the first gear driven by the first screw shaft, the
first and fourth gears rotating coaxially at differential
rotational speeds.
6. The apparatus of claim 5 wherein the second gear set comprises a
fifth, sixth and seventh gears in mutual rotational engagement, the
fifth gear driven by the fourth gear, the fifth and seventh gears
rotating coaxially in opposing rotational senses.
7. A marine drive apparatus adapted for being engaged with and
driven by a single engine drive shaft penetrating the hull of a
vessel, the apparatus comprising: a second universal joint secured
to the hull; a first gear set driven by a shaft of the second
universal joint; a first screw shaft driven by a first universal
joint; a second gear set driven by the first gear set; a second
screw shaft driven by the first gear set and supporting a second
screw; and a first screw supported by the first screw shaft; the
first and second gear sets, enclosed within a water-tight
enclosure; the first gear set enabling rotational speed
differentiation between the first and second screw shafts; the
second gear set enabling rotational sense reversal between the
second and a third screw shafts; the apparatus further comprising
an actuator engaged with the enclosure and secured to the hull, the
actuator positioned and adapted for changing an angle of attack of
the second and third screws.
8. The apparatus of claim 7 wherein the first gear set comprises a
first, second, third and fourth gears in mutual rotational
engagement, the first and fourth gears rotating coaxially at
differential rotational speeds.
9. The apparatus of claim 8 wherein the second gear set comprises a
fifth, sixth and seventh gears in mutual rotational engagement, the
fifth gear driven by the fourth gear, the fifth and seventh gears
rotating coaxially in opposing rotational senses.
10. A marine drive apparatus adapted for being engaged with and
driven by an engine drive shaft penetrating the hull of a vessel,
the apparatus comprising and mutually engaged in a sequence of: a
first universal joint adapted for securement to the hull; a first
screw shaft supporting a first screw; a second universal joint
driven by the first screw shaft; a first gear set driven by a shaft
of the second universal joint; a second screw shaft driven by the
first gear set; a second gear set driven by the second screw shaft;
a third screw shaft driven by the second gear set and supporting a
third screw; and a second screw supported by the second screw shaft
at a terminal end thereof; the first and second gear sets enclosed
within a water-tight enclosure; the first gear set enabling
rotational speed differentiation between the first and second screw
shafts; and the second gear set enabling rotational sense reversal
of the third screw shaft relative to the second screw shaft.
11. The apparatus of claim 10 wherein the first gear set comprises
a first, second, third and fourth gears in mutual rotational
engagement, the first gear driven by the first screw shaft, the
first and fourth gears rotating coaxially at differential
rotational speeds.
12. The apparatus of claim 11 wherein the second gear set comprises
a fifth, sixth and seventh gears in mutual rotational engagement,
the fifth gear driven by the fourth gear, the fifth and seventh
gears rotating coaxially in opposing rotational senses.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0004] Not applicable.
REFERENCE TO A "MICROFICHE APPENDIX"
[0005] Not applicable.
BACKGROUND OF THE INVENTION
[0006] 1. Field of the Present Disclosure
[0007] This disclosure relates generally to marine drives, and more
particularly to a marine drive capable of efficiently converting
the output of powerful marine engines to forward thrust, to provide
rotational speed differentials between plural screws driven by a
single engine shaft, and to provide variable thrust vector angle of
attack.
[0008] 2. Description of Related Art Including Information
Disclosed Under 37 CFR 1.97 and 1.98
[0009] Kirin, U.S. Pat. No. 1,595,949, discloses a boat comprising
a hull having a cylindrical portion and keel supported centrally
upon the under side thereof; side fins arranged upon the opposite
and extending downwardly and oppositely and obliquely disposed upon
he opposite sides of the keel for eliminating the upper locking and
rolling effect of water craft, a drive shaft mounted within the
cylindrical member and having propulsion conical-shaped members
arranged in like end to end relation upon the opposite ends of the
drive shaft exteriorly of the cylindrical portion, and the outer
sides of the conical-shape members having helically and spiraled
positioned plates radiating from the apex of the conical-shaped
members and rearwardly in spaced relation to the periphery thereof
to whereby the particular water craft may be propelled and impelled
from both ends of the craft in a single operation upon the common
drive shaft.
[0010] Pierce, U.S. Pat. No. 1,910,561, discloses an outboard
motor, in combination, a housing enclosing a vertically disposed
power shaft, the housing being rotatable about a vertically
disposed line, a horizontally disposed propeller shaft disposed at
the lower end of the propeller shaft and operatively connected
thereto for driving movement therefrom, the propeller shaft
projecting both forwardly and rearwardly from the housing, a
propeller secured to the propeller shaft forwardly of the housing,
and a propeller secured to the propeller shaft rearwardly of the
housing, the last mentioned propeller having a greater pitch than
the first mentioned propeller.
[0011] Stechauner, U.S. Pat. No. 1,813,552, discloses a propelling
mechanism, the combination with an underwater housing, of a power
transmission shaft journalled in the housing and extending
lengthwise thereof and provided with a bevel gear, a sleeve shaft
extending at right angles to the first named shaft and journalled
in one end of the housing and provided with a bevel gear meshing
with the first named gear and having a shoulder exterior of the
housing, a propeller mounted on the second sleeve shaft and
abutting the shoulder, a third shaft extending at right angles to
the first shaft and journalled in the housing and extending through
the sleeve shaft and provided with a bevel gear meshing with the
first named bevel gear, and a propeller mounted on the outer end of
the third shaft, the propellers being of substantially similar
pitch ratio and size but of opposite pitch and mounted adjacent
each other, the second and third named bevel gears being disposed
on opposite sides of the first named bevel gear and being of the
same pitch diameter.
[0012] Waterval, U.S. Pat. No. 2,691,356, discloses a multiple
propeller drive for ships comprising in combination, a ship's hull
having an opening therein, a block member mounted inside the hull,
a casing supported by the block member, a shaft journalled in the
casing, a pulley mounted on the shaft, a coupling at one end of the
latter adapted to connect the shaft to a power unit, a strut
secured to the hull, a second casing integral with the lower end of
the strut, a second shaft having a propeller at each end thereof,
and being mounted in the second casing, a second pulley arranged on
the second shaft, and a belt mounted on the first and second pulley
and adapted to actuate the second shaft, guides for the first shaft
and being attached to the end of the first casing; bearing blocks
supporting the first shaft, and screws mounted in the latter for
vertical movement, and handwheels threaded upon the screws, whereby
to adjust the belt drive.
[0013] Arneson, U.S. Pat. No. 4,645,463, discloses a marine
outdrive attachable to the transom of a boat having an inboard
engine. The marine outdrive includes a tubular support casing
securable to and extendable rearwardly of the boat's transom and
having a ball socket at its rear end. The ball socket receives a
ball at the front end of a tubular, propeller shaft carrier having
a conical outer surface. A drive shaft connectable to the inboard
engine is journalled in the support casing. A propeller shaft is
journalled in the propeller shaft carrier and has a propeller
mounted thereon at the rear end of the propeller shaft carrier. A
universal joint couples the two shafts together, the center of such
joint substantially coinciding with the point about which the ball
pivots within the socket. Hydraulic steering cylinders are attached
to the propeller shaft carrier to pivot the latter about a steering
axis extending through the pivot point of the ball. A hydraulic
trim cylinder extends between the transom and the propeller shaft
carrier to swing the propeller shaft carrier about a laterally
extending trim axis extending through the pivot point of the ball.
The upper end of the trim cylinder is pivotally mounted on the
transom at a location above and vertically aligned with the pivot
point of the ball or at a location above and forwardly of such
pivot point. Improved fins are provided on the propeller shaft
carrier near the propeller to stabilize the boat. The drive shaft
of the inboard motor can be directly connected to the joint or
offset from the joint and coupled thereto by a vertically extending
transmission.
[0014] McCormick, U.S. Pat. No. 4,790,782, discloses a marine stem
drive for a boat that includes a propeller assembly having a
carrier for a pair of concentric drive shafts to which are mounted
a pair of closely adjacent fore and aft coaxial surface piercing
propellers mounted on a common axis. The carrier also includes a
downwardly extending skeg. The shafts are connected to a source of
power and drive the propellers in contra-rotating relationship at
essentially equal rotational velocities. The carrier is connected
to devices for swinging the carrier laterally for steering, and
also vertically. A control is provided for positioning and
maintaining the carrier vertically such that both contra-rotating
propellers are continuously disposed in surface piercing position
during normal operation of the drive. The result is that lateral
forces created on the propeller carrier by one rotating surface
piercing propeller are counterbalanced by the other propeller when
the skeg is parallel to the boat centerline. The leading edges of
both propellers are relatively sharp for surface piercing, while
the training edges of both propellers are relatively blunt.
[0015] Brandt, U.S. Pat. No. 4,840,136, discloses a
double-propeller drive unit for boats, in which the under-water
housing of the drive unit is designed so that the pressure center
for the transverse force on the drive housing caused by water flow
is located in front of the steering axis of the drive unit.
[0016] Brandt, U.S. Pat. No. 4,619,584, discloses a boat propeller
drive with double, counter-rotating propellers that is
distinguished by the after propeller having one more blade than the
fore propeller as well as a smaller diameter than the fore
propeller.
[0017] Bankstahl et al., U.S. Pat. No. 4,887,983, discloses a chain
drive marine propulsion system that employs dual counterrotating
propellers. The propellers are mounted to concentric propeller
shafts disposed in the lower end of a depending gearcase. The
concentric propeller shafts are each provided with a lower sprocket
engaging a chain. A counterrotation mechanism is provided for
driving the chains in opposite directions, thereby resulting in
counterrotation of the propellers. Various embodiments for driving
the chains in opposite directions are disclosed.
[0018] Newman et al., U.S. Pat. No. 4,932,907, discloses a marine
propulsion system that includes a steerable lower gearcase portion
and a drive mechanism including a chain drive for driving dual
counterrotating propellers. The dual propellers are rotatably
mounted to the lower steerable gearcase portion by means of inner
and outer coaxially extending propeller shafts. A sprocket is
mounted to each propeller shaft, and first and second chain
portions extend between the propeller shaft sprockets and a pair of
upper drive sprockets, preferably disposed above the water line
during boat operation. Coaxially extending inner and outer drive
shafts are interconnected with the engine output shaft, and are
adapted for counterrotation in response to rotation thereof. The
coaxial drive shafts are interconnected with the upper drive
sprockets for driving such sprockets in opposite rotational
directions, thereby resulting in movement of the first and second
chain portions in opposite directions. The longitudinal axis of the
inner and outer drive shafts defines the steering axis about which
the lower steerable gearcase portion is pivotable.
[0019] Bankstahl et al., U.S. Pat. No. 5,009,621, discloses a dual
counterrotating propeller drive mechanism for a marine propulsion
system that incorporates a torque splitting device which consists
of a differential gear means and a ratio gear means. The torque
splitting device assigns a selectable fixed fraction of the engine
torque to each propeller regardless of power, thrust, and speed
conditions. The rear one of the two propellers adjusts its
rotational speed relative to the front propeller in response to
changes in the front propeller's wake and in this way maintains
optimum propulsive efficiency over a wide range of operating
conditions. Furthermore, precise matching of front and rear
propeller parameters for a given application is no longer
required.
[0020] Meisenburg et al., U.S. Pat. No. 5,376,031, discloses a
marine drive has two counter-rotating surface operating propellers.
The lower horizontal torpedo portion of the housing has an upper
zone with outer surface profiles along horizontal cross-sections
defining wedges with sharp leading tips forming a sharp leading
edge for slicing through the water, the sharp leading tips defining
the sharp leading edge defining a first line extending downwardly
and rearwardly at a first angle relative to vertical. The torpedo
portion has a lower zone with outer surface profiles along
horizontal cross-sections defining wedges with sharp leading tips
defining a second line extending downwardly and rearwardly at a
second angle relative to vertical. The housing includes a skeg
extending downwardly from the lower zone of the torpedo portion,
the skeg having a leading edge defining a third line extending
downwardly and rearwardly at a third angle relative to vertical.
The third angle is greater than the first angle and less than the
second angle. The first, second and third lines all intersect at
the same point which point is on the rotational axis of the
concentric counter-rotating propeller shafts.
[0021] Meisenburg et al., U.S. Pat. No. 5,376,034, discloses a
surfacing marine drive that has a drive housing with a fore exhaust
passage forward of the vertical bore housing the driveshaft, right
and left exhaust passages extending rearwardly from the fore
exhaust passage on opposite right and left sides of the vertical
bore, and an aft exhaust passage extending rearwardly from the
right and left exhaust passages and aft of the vertical bore and
discharging exhaust into dual counter rotating surface operating
propellers.
[0022] Ogino, U.S. Pat. No. 5,575,698, discloses a transmission for
a counter-rotational propeller system of a watercraft outboard
drive with an increased flow area for exhaust discharge behind the
transmission within the lower unit. The transmission includes a
pair of counter-rotating gears. A front clutch selectively drives
an inner propulsion shaft by engaging the front gear. A rear clutch
selectively drive an outer propulsion shaft by engaging either of
the gears. The front clutch lies forward of the front gear and the
rear clutch is interposed between the gears. The clutching
mechanism thus entirely lies forward of the rear gear to provide
more space for exhaust discharge flow behind the transmission.
[0023] Sambino et al., U.S. Pat. No. 5,759,073, discloses a
propulsion system for a marine drive, which includes a pair of
counter-rotating propellers, provides improved acceleration from
idle or low speeds. Engine exhaust from an engine which powers the
marine drive is conveyed to the water about each of the propellers.
The exhaust gases aerate the water about each propeller to reduce
drag resistance on each propeller. Several embodiments of the
propulsion system are disclosed which convey the exhaust gases to
both propellers for this purpose.
[0024] Alexander, Jr. et al., U.S. Pat. No. 5,766,047, discloses a
twin propeller marine propulsion unit for a watercraft. A vertical
drive shaft operably connected to the engine is journalled for
rotation in a lower gear case and carries a beveled pinion that
drives a pair of coaxial bevel gears. An inner propeller shaft and
an outer propeller shaft are mounted concentrically in the lower
torpedo-shaped section of the gear case and each propeller shaft
carries a propeller. To provide forward movement for the
watercraft, a sliding clutch, is moved in one direction to operably
connect a first of the bevel gears with the inner propeller shaft
to thereby drive the rear propeller. When the engine speed reaches
a pre-selected elevated value, a hydraulically operated multi-disc
clutch is actuated to operably connect the second of the bevel
gears to the outer propeller shaft, to thereby drive the second
propeller in the opposite direction. With this construction only a
single propeller is driven at low engine speeds and the second
propeller is driven when the engine speed reaches the pre-selected
value.
[0025] Iriono et al., U.S. Pat. No. 5,800,223, discloses a marine
propulsion device that improves the handling characteristics and
the responsiveness of the watercraft on which it is used. The
propulsion device includes a pair of counter-rotating propellers.
At least the blades of the front propeller each have a mean camber
line in cross-section which has a generally constant radius of
curvature. This blade shape reduces cavitations and permits the
rear propeller to be mounted closer to the front propeller, and
consequently closer to the steering axis of the outboard drive. As
a result, steering torque is reduced. The blades of the rear
propeller also are not more than thirty percent smaller than the
blades of the front propeller, and the average pitches of the
propellers do not differ by more than one to four percent. These
blade configurations of the front and rear propellers improve the
stability of the watercraft when turning, thereby reducing chine
walk, as well as improve the responsiveness of the watercraft.
[0026] Sumino, U.S. Pat. No. 5,807,151, discloses a blade design
for a counter-rotating propeller system that improves the
performance of the outboard drive on which is it employed when the
propellers are run partially exposed. The propeller system includes
a pair of counter-rotating propellers that rotate in opposite
directions about a common axis. The rear propeller has a smaller
diameter--about 92% of the front propeller--and a total blade face
surface area of about 85% of the total blade face surface area of
the front propeller. The blades of the front and rear propellers
desirably have the same camber and generally the same pitch. The
rear propeller pitch is between 90% and 110% of the front propeller
pitch. These blade parameters improve the efficiency of the rear
propeller over prior designs when the propellers run partially
exposed in order to maximize the thrust produced by the propulsion
system.
[0027] Jordan, U.S. Pat. No. 6,821,169, discloses a hybrid
gear/sprocket-based transmission for driving a pair of coaxial,
counter-rotating propellers in vessels. A drive shaft couplable to
an engine crank shaft extends rearward into the transmission case,
and a pair of coaxial driven shafts extend rearward out of the
transmission case, to which are attachable a pair of propellers. A
gear train, containing an even number of gears, reverses the
rotational direction of the engine; a flexible member retains the
rotational direction of the engine. Improved stability
characteristics are imparted by supporting the drive shaft at two
points and also by positioning the drive and the driven shafts in
vertical alignment.
[0028] Reuter et al., U.S. Pat. No. 6,899,576, discloses a
watercraft drive for a watercraft having front and rear propellers
respectively mounted on a drive shaft in coaxial longitudinally
displaced relationship, each of said propellers having at least two
blades, the front and rear propellers having equal diameters and
being driven at like rotational velocities. The central portion of
the rear propeller up to a diameter equal to the diameter of the
water jet arriving at the rear propeller, which due to the action
of the front propeller has a contracted cross section, is designed
to optimize the jet energy exiting the front propeller. The rear
propeller has an annular area extending from the central portion to
the outer circumference of the rear propeller, being designed with
the same design as characterizes the front propeller. The annular
area of the rear propeller receives a flow of surrounding ambient
water.
[0029] The related art described above discloses outboard drives,
L-drive arrangements and also near coaxial drive shaft-screw axis
drives. Only the later is significant relative to the present
disclosure. The former marine drive types generally provide a right
angle drive train which is not of interest because of its
relatively lower efficiency. However, Sage, U.S. Pat. No.
6,431,927, Arneson, U.S. Pat. No. 4,645,463, McCormick, U.S. Pat.
No. 4,790,782 and Jordan, U.S. Pat. No. 6,821,169 all coaxial
drives which are applicable to larger water craft such as yachts.
All but McCormick also teach the use of a mechanism for adjusting
the angle of attack of marine screws.
[0030] The present disclosure distinguishes over the prior art
providing heretofore unknown advantages as described in the
following summary.
BRIEF SUMMARY OF THE INVENTION
[0031] This disclosure teaches certain benefits in construction and
use which give rise to the objectives described below.
[0032] Engines for small ships and yachts are able to generate
significant thrust. However, prior art marine drives for ships and
yachts are relatively inefficient with low speed and high fuel
consumption. Such ships and yachts are most efficient at lower
speeds where the hull is plowing. Incremental increases in screw
RPM are not matched by equivalent incremental hull speeds. This is
because, when plowing, a ship's hull must displace ever greater bow
wave mass as speed increases and such mass increases non-linearly
with hull speed. The present invention provides a solution to this
problem enabling larger craft to move more quickly through the
water while using relatively less fuel to do so.
[0033] By changing the angle of attack of a ship's drive screws the
hull may be raised in the water so that it displaces less water and
produces a smaller bow wave. To achieve greater screw thrust, dual
in-line screws are used with counter-rotation to provide a
significant improvement in thrust without producing undesirable
screw steering effects. However, because a change in angle of
attack of a ship's screws to provide hull lift is sub-optimal in
producing forward thrust, the first effect tends to be negated by
the second effect. To overcome this problem, the screws used for
lift are able to be placed at an optimal angle for doing so, while
a third screw is positioned for maximum forward thrust. To provide
for simplicity and economy of enabling this capability, all three
screws are driven by a single drive shaft. The present invention
reduces fuel consumption while permitting relatively higher speeds
in larger boats and yachts.
[0034] A primary objective inherent in the above described
apparatus and method of use is to provide advantages not taught by
the prior art.
[0035] Another objective is to provide a ship's drive having three
coaxial screws that are driven from a single drive shaft.
[0036] Another objective is to provide such a ship's drive where,
simultaneously, each screw may operate at a different rotational
speed.
[0037] Another objective is to provide such a ship's drive capable
of changing its angle of attack.
[0038] Another objective is to provide such a ship's drive wherein
at least one of the screws does not change its angle of attack
while, at the same time, at least one other of the screws does
change its angle of attack.
[0039] Other features and advantages of the present invention will
become apparent from the following more detailed description, taken
in conjunction with the accompanying drawings, which illustrate, by
way of example, the principles of the presently described apparatus
and method of its use.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0040] Illustrated in the accompanying drawing(s) is at least one
of the best mode embodiments of the present invention In such
drawing(s):
[0041] FIGS. 1 and 2 are schematic diagrams of the presently
described apparatus as viewed from one side with FIG. 1 showing a
low water line and FIG. 2 showing a high water line; and
[0042] FIG. 2 is a detailed schematic of a gear system thereof,
also as viewed from one side.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The above described drawing figures illustrate the described
apparatus and its method of use in at least one of its preferred,
best mode embodiment, which is further defined in detail in the
following description. Those having ordinary skill in the art may
be able to make alterations and modifications to what is described
herein without departing from its spirit and scope. Therefore, it
must be understood that what is illustrated is set forth only for
the purposes of example and that it should not be taken as a
limitation in the scope of the present apparatus and method of
use.
[0044] Described now in detail and shown in FIG. 1 is a marine
drive apparatus 5 adapted for being engaged with and driven by an
engine drive shaft 10 of a vessel. The vessel's hull 20 is
penetrated by the engine drive shaft 10 which then extends
rearwardly relative to the hull 20.
[0045] Referring still to FIG. 1, it is shown that the drive
apparatus 5 includes a first universal joint 30 which is adapted by
bracket 32 for securement to the hull 20 and receives the drive
shaft 10 for rotation. As shown in this figure, shaft 10 extends
from hull 20 at a downward angle as is conventional, yet first
screw shaft 40 needs to be placed at a more nearly horizontal
orientation. Therefore, joint 30 enables driving force to change
direction between shafts 10 and 40. Universal joints are well known
in marine drive systems, for instance in providing changes in the
angle of attack of the vessel's screws. A double Cardan universal
joint is preferably used as described in the Sage reference shown
above. The first screw shaft 40 supports a first screw 42 and, in
one embodiment, as shown in FIG. 1, it is engaged with a second
universal joint 50 secured by bracket 52 to hull 20 and driven by
the first screw shaft 40. Clearly then, in the embodiment shown in
FIG. 1, screw 42 is able to maintain its, more or less, horizontal
attitude producing forward thrust V.sub.F an optimal vector for
producing forward thrust, while, by adjusting joint 50, screws 72
and 92 are able to be set at an angle of attack that will optimize
lift vector V.sub.L.
[0046] In FIG. 2 we see that the hull is set at greater depth
thereby displacing a larger bow wave as the vectors V.sub.F and
V.sub.L are collinear. Also in this figure we see that all three
screws 42, 72 and 92 are always coaxial since joint 50 is not
used.
[0047] As shown now in FIG. 3, a first gear set 60 is driven by a
shaft 52 of the second universal joint 50 which, in turn, drives a
second screw shaft 70. A second gear set 80 is driven by the second
screw shaft 70. A third screw shaft 90 is driven by the second gear
set 80 and supports the third screw 92. The second screw 72 is
supported by the second screw shaft 70 at its terminal end. The
first and second gear sets 60, 80 are enclosed within a water-tight
enclosure 100 and the second and third screw shafts 70 and 90 as
well as a shaft 52 of the second universal joint 50, penetrate the
enclosure 100 through water tight rotational seals which are well
known in the art and not depicted in the figures. In an alternate
embodiment, the second universal joint 50 is not used, and in this
case, the first screw shaft 40 penetrates the enclosure 100 through
the water tight rotational seal. In FIG. 3 bearing sets and
supports for the bearing sets are not shown as this detail is
considered to fall under routine engineering practice and such
detail would not provide an improvement to the concepts presented
but would add unnecessary detail and confusion in FIG. 3.
[0048] The arrows shown on the several gears and shafts in FIG. 3
indicate their rotational sense. The gear enablements shown in this
description are bevel gears, but different gear types and
arrangements may be substituted by those of skill in the art. The
first gear set 60 enables rotational speed differentiation between
the first 40 and second 70 screw shafts so that screws 72 and 92
may be operated at a higher or lower rotational speed than screw
42. This has been found to be greatly beneficial as screws 72 and
92 are functional for driving hull 20 to sit higher in the water
for planing or near planing operation so as to thereby achieve
higher hull speed for improved fuel economy. The function of
initially lifting the hull 20 for planing operation requires
significant thrust, but after reaching a higher hull speed and
planing operation, the angle of attack of screws 72 and 92 may
preferably be brought near level so as to better contribute to the
forward thrust of the vessel. The second gear set 80 enables
opposing rotational directions for the second 70 and third 90 screw
shafts. It is clear from FIG. 3 that the second 70 and third 90
screw shafts are arranged and rotate coaxially. In the alternate
embodiment, the universal joint 50 is not used, so that the first
screw shaft 40 is also aligned coaxially with the second 70 and
third 90 screw shafts and screws 42, 72 and 92 are also coaxially
aligned and change their angle of attack at the same time as driven
by actuator 120.
[0049] Referring still to FIG. 3 the first gear set 60 comprises a
first gear 61 driven by the second universal joint 50 in one
embodiment, or by the first screw shaft 40 in another embodiment.
The first gear 61 is engaged with a second gear 62 which is engaged
with a third gear 63, which is engaged with a fourth gear 64,
wherein the first 61 and fourth 64 gears rotate coaxially at
different rotational speeds depending on the number of gear teeth
in each of the gears 61, 62, 63, and 64.
[0050] The second gear set 80 comprises a fifth gear 85 driven by
the fourth gear 64 and a sixth gear 86 driven by the fifth gear 85,
and a seventh gear 87 driven by the sixth gear 86. As shown, the
fifth 85 and seventh 87 gears are in coaxial rotation but rotate in
opposing senses.
[0051] An actuator 120 is engaged with the enclosure 100 and is
adapted for securement to the hull 20 by bracket 122. The actuator
120 is positioned and adapted for changing an angle of attack of
the second 70 and third 90 screw shafts and, by that, the second 72
and third 92 screws. The actuator 120 and its arrangement relative
to the hull and the enclosure 100 may be in accordance with FIGS. 1
and 2 of the McCormick U.S. Pat. No. 4,790,782, or FIG. 5 of the
Sage U.S. Pat. No. 6,431,927, or FIGS. 1-13 of the Arneson U.S.
Pat. No. 4,645,463, all of which patents are hereby incorporated by
reference herein as general teachings of the physical and
operational enablements of marine screw angle of attack
adjustment.
[0052] It should be recognized that one embodiment of the present
invention may include only screws 72 and 92 in FIG. 1 or FIG. 2 but
not screw 42, although this is a less effective solution to the
above described problem. Also, in a still further embodiment, the
enclosure 100 may be fixed to the hull 20 without possibility of
adjusting it angle of attack. In this approach, the angle of attack
of screws 72 and 92 are fixed at a suboptimal position that can
provide an optimal solution for the forward thrust vector V.sub.F,
or an optimal solution for the lift thrust vector V.sub.L, but not
both since screw 42 is not used.
[0053] The enablements described in detail above are considered
novel over the prior art of record and are considered critical to
the operation of at least one aspect of the apparatus and its
method of use and to the achievement of the above described
objectives. The words used in this specification to describe the
instant embodiments are to be understood not only in the sense of
their commonly defined meanings, but to include by special
definition in this specification: structure, material or acts
beyond the scope of the commonly defined meanings. Thus if an
element can be understood in the context of this specification as
including more than one meaning, then its use must be understood as
being generic to all possible meanings supported by the
specification and by the word or words describing the element.
[0054] The definitions of the words or drawing elements described
herein are meant to include not only the combination of elements
which are literally set forth, but all equivalent structure,
material or acts for performing substantially the same function in
substantially the same way to obtain substantially the same result.
In this sense it is therefore contemplated that an equivalent
substitution of two or more elements may be made for any one of the
elements described and its various embodiments or that a single
element may be substituted for two or more elements in a claim.
[0055] Changes from the claimed subject matter as viewed by a
person with ordinary skill in the art, now known or later devised,
are expressly contemplated as being equivalents within the scope
intended and its various embodiments. Therefore, obvious
substitutions now or later known to one with ordinary skill in the
art are defined to be within the scope of the defined elements.
This disclosure is thus meant to be understood to include what is
specifically illustrated and described above, what is conceptually
equivalent, what can be obviously substituted, and also what
incorporates the essential ideas.
[0056] The scope of this description is to be interpreted only in
conjunction with the appended claims and it is made clear, here,
that each named inventor believes that the claimed subject matter
is what is intended to be patented.
* * * * *