U.S. patent number 3,641,964 [Application Number 04/867,598] was granted by the patent office on 1972-02-15 for water jet propulsion unit.
Invention is credited to Robert B. Lee.
United States Patent |
3,641,964 |
Lee |
February 15, 1972 |
WATER JET PROPULSION UNIT
Abstract
A propulsion unit for a boat hull of the type including a
transom and an engine disposed forwardly of the transom and
provided with a rearwardly facing output shaft spaced above the
lower marginal edge portion of the transom. A hollow elongated
housing is provided and supported from the lower marginal edge
portion of the transom in rearwardly projecting position and the
housing has a longitudinal impeller shaft journaled therein whose
forward end projects forwardly through the transom. The forward end
of the housing is provided with a downwardly opening outlet
immediately rearward of the lower marginal edge portion of the
transom and an offset drive train assembly is provided forwardly of
the transom and drivingly connects the elevated engine output shaft
to the lower forward end of the impeller shaft.
Inventors: |
Lee; Robert B. (Homestead,
FL) |
Family
ID: |
25350108 |
Appl.
No.: |
04/867,598 |
Filed: |
October 20, 1969 |
Current U.S.
Class: |
440/42 |
Current CPC
Class: |
B63H
11/113 (20130101) |
Current International
Class: |
B63H
11/113 (20060101); B63H 11/00 (20060101); B63h
011/00 (); B63h 001/14 () |
Field of
Search: |
;115/12,12A,14,16,34,35,41 ;60/221 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Blix; Trygve M.
Claims
What is claimed as new is as follows:
1. In combination with a boat hull of the type including a bottom
from whose rear end a transom projects upwardly and from which an
upper powered drive shaft is journaled forwardly of the transom at
an upper elevated position relative to the bottom, a hollow
elongated housing supported in rearwardly projecting position from
the lower marginal portion of said transom, a lower longitudinal
impeller shaft journaled in said housing and including a forward
end projecting through said transom at an elevation below said
drive shaft, the rear end of said housing being open, the forward
end of said housing including a downwardly opening inlet opening
outwardly immediately rearward of the lower marginal portion of
said transom, an impeller member mounted on said impeller shaft for
rotation therewith intermediate said inlet and the open rear end of
said housing, and drive train means disposed forward of said
transom wholly within said boat hull drivingly connecting said
drive shaft to said impeller shaft.
2. The combination of claim 1 wherein said drive train means
includes an upstanding housing supported from the inner side of
said transom from whose upper portion said drive shaft is journaled
and including spaced front and rear walls from which longitudinally
spaced portions of said forward end portions are journaled, and a
pair of aligned drive wheels mounted on said drive and impeller
shafts within said upstanding housing and including drive means
drivingly connecting the output shaft wheel to the impeller shaft
wheel, said impeller shaft being free of associated journal means
rearward of said impeller member.
3. The combination of claim 2 wherein said housing includes a lower
end portion defining a sump, and lubricating fluid disposed in said
sump at least to a level below which the lower periphery of the
lower sprocket wheel projects.
4. The combination of claim 1 including a larger diameter outer
sleeve telescoped over the rear end of said housing and supported
therefrom for oscillation about a vertical axis closely adjacent
the rear end of said housing.
5. The combination of claim 4 including remotely operable control
means operatively connected between said hull and said sleeve for
adjustably angularly displacing said sleeve relative to said
housing.
6. The combination of claim 1 wherein said inlet opens downwardly
through a plane substantially coinciding with the under surface
portions of said bottom immediately forward of said inlet.
Description
The water jet propulsion unit of the instant invention has been
specifically designed for use in pleasure boats and provides a
means whereby a water jet propulsion unit mounted to the rear of
and on the lowest portion of the transom of the boat may be driven
by an engine disposed within the boat whose output shaft is
elevated above the impeller shaft of the water jet propulsion unit.
Even when an inboard engine is utilized to drive a water jet
propulsion unit mounted on a boat whose aft bottom surfaces are
generally transversely flat, the output shaft of the engine is
elevated above a horizontal plane in which the impeller shaft of
the water jet propulsion unit would be disposed if the impeller
shaft was horizontal. Accordingly, many water jet propulsion units
utilize a drive train which is slightly rearwardly and downwardly
inclined so that the driving engine may be properly mounted on
longitudinal stringers above the inner surfaces of the bottom of
the boat while the impeller portion of the water jet propulsion
unit is located only slightly above the bottom of the boat. In
addition, some water jet propulsion units have water intakes
therefor which open downwardly through the bottom of the boat a
considerable distance forward of the transom of the boat and which
therefore include below the waterline connections within the boat
which are subject to leakage.
The water jet propulsion unit of the instant invention, however,
includes only one through the hull fitting for the impeller shaft
which may be readily sealed by conventional means and the unit
further includes an offset drive assembly whereby an elevated
engine output shaft may be drivingly coupled to a lower impeller
shaft. These structural features of the propulsion unit of the
instant invention therefore function to eliminate potential areas
of leakage and enable horizontal mounting of both the propulsion
engine and the impeller shaft, even in the deep V type of hull
which is becoming increasingly popular.
The main object of this invention is to provide a water jet
propulsion unit whereby the elevated output shaft of a horizontally
disposed engine supported within a boat may be drivingly coupled to
a lower horizontal impeller shaft of a water jet propulsion unit
disposed rearwardly of the transom of the associated boat.
Another object of this invention, in accordance with the
immediately preceding object, is to provide a simplified water jet
propulsion unit which may be utilized on substantially all types of
conventional forms of pleasure boats as well as boats designed for
uses other than pleasure.
A still further object of this invention is to provide a water jet
propulsion unit of a type which may be readily driven by an inboard
engine through a conventional form of marine transmission.
A still further important object of this invention is to provide a
water jet propulsion unit that may be readily adapted to boats of
various sizes and displacement for maximum efficiency in operation
in conjunction with a given power supply.
A final object of this invention to be specifically enumerated
herein is to provide a water jet propulsion unit which will conform
to conventional forms of manufacture, be of simple construction and
easy to install so as to provide a device that will be economically
feasible, long lasting and relatively trouble free in
installation.
These together with other objects and advantages which will become
subsequently apparent reside in the details of construction and
operation as more fully hereinafter described and claimed,
reference being had to the accompanying drawings forming a part
hereof, wherein like numerals refer to like parts throughout, and
in which:
FIG. 1 is a fragmentary side elevational view of the rear portion
of a boat hull utilizing the water jet propulsion unit of the
instant invention and with portions of the hull of the boat being
broken away and illustrated in vertical section to more clearly
illustrate the installation of the propulsion unit within the
boat;
FIG. 2 is a fragmentary rear elevational view of the assemblage
illustrated in FIG. 1;
FIG. 3 is a fragmentary bottom plan view of the aft portion of the
boat;
FIG. 4 is a fragmentary perspective view of the transom of the boat
illustrating the mount for the housing of the water jet propulsion
unit;
FIG. 5 is an enlarged fragmentary longitudinal vertical sectional
view taken substantially upon the plane indicated by the section
line 5--5 of FIG. 2; and
FIG. 6 is a transverse vertical sectional view taken substantially
upon the plane indicated by the section line 6--6 of FIG. 5 and on
somewhat of an enlarged scale.
Referring now more specifically to the drawings the numeral 10
generally designates a conventional form of deep V hull including a
bottom 12, opposite sides 14 and 16, and a transom 18.
The boat hull 10 has a conventional inboard engine 19 mounted
therein driving through any suitable form of marine transmission
22. The transmission 22 includes an output or drive shaft 24 and
the water jet propulsion unit of the instant invention is generally
referred to by the reference numeral 26. The unit 26 includes a
mount 20 mounted on the exterior of the transom 18 by means of
suitable fasteners 21 and includes an opening 29 through which a
bearing sleeve 31 extends. The bearing sleeve 31 is carried by the
rear wall 28 of an offset drive assembly referred to in general by
the reference numeral 30 disposed forward of the transom 18. The
drive assembly 30 includes a vertically elongated housing 32 of
which the rear wall 28 comprises a part and the housing 32 is
secured to the inner surface 34 of the transom 18 by means of
suitable fasteners 36. The housing 32 includes a removable front
wall or cover 38 and an output shaft 40 has its forward end
journaled by a bearing 42 supported from the front wall or cover 38
and its rear end journaled through the sleeve 31. The rear end of
the sleeve 31 has a packing gland 44 mounted thereon rearward of
the transom 18 and the rear end of the sleeve 31 forward of the
packing gland 44 is sealingly received through the opening 24.
The output shaft 24 of the transmission 22 comprises the input
shaft for the drive assembly 30 and a double sprocket wheel 46 is
mounted on the shaft 24 within the housing 32. Further, a double
sprocket wheel 48 is mounted on the forward end of the shaft 40
within the housing 32 and a pair of flexible chains 50 are
entrained about the sprocket wheels 46 and 48.
An elongated housing 52 includes a flanged large diameter end 54
secured to the mount 20 by means of suitable fasteners 56 and the
large diameter end 54 of the housing 52 includes a downwardly
opening neck or inlet 58 whose lower end is coplanar with and
disposed immediately rearward of the rear marginal edge portion of
the bottom 12. The inlet neck 58 has a plurality of forwardly and
downwardly inclined transverse bars 60 secured thereacross to
prevent to entrance of large foreign material into the housing 52
and a pair of conventional three-bladed propellers 62 are mounted
on the rear end of the shaft 40 in the rear portion of the large
diameter end portion 54 of the housing 52.
The housing 52 necks down rearward of the large diameter end
portion 54 as at 64 and emerges smoothly into a discharge neck or
nozzle 66 which opens horizontally rearwardly of the transom 18.
The discharge neck or nozzle 66 has a pair of right angularly
disposed diametric vanes 68 and 70 mounted therein to prevent the
water being discharged from the neck 66 from swirling in the
direction of the rotation of the propeller 62 and a steering sleeve
72 is loosely telescoped over the discharge nozzle or neck 66 and
pivotally supported therefrom by means of pivot fasteners 74. It
will be noted that the forward end of the steering sleeve 72 is
pivotally supported from the forward end of the discharge neck or
nozzle 66 and that the forward edges of the steering sleeve 72 are
provided with notches 76 whereby the steering sleeve 72 may be
oscillated approximately 45.degree. to either side of a center
position aligned with the discharge neck or nozzle 66.
A steering lever 78 is pivotally supported from the large diameter
end portion 54 of the housing 52 by means of a fastener 80 and the
steering lever 78 includes a rear end which is pivotally secured to
the rear end of the steering sleeve 72 by means of a pivot fastener
82. The forward end of the steering lever 78 projects upward from
the housing 52 and includes a forwardly directed end portion 84
which projects through a slot 86 in the upper portion of the
transom 18 and has a control cable 88 connected thereto for
oscillation of the lever 78 about the pivot fastener 80 in order to
oscillate the steering sleeve 72.
It will be noted from FIG. 1 of the drawings that the engine 19 and
transom 18 are horizontally disposed and from FIG. 5 of the
drawings that the impeller shaft 40 is horizontally disposed.
Further, it may be observed from FIG. 5 of the drawings that the
horizontally disposed output shaft 24 of the transmission 22 is
elevated above the impeller shaft 40 and that the offset drive
assembly 30 provides a means whereby the upper output shaft of the
transmission 22 may be drivingly coupled to the lower impeller
shaft 40. Also, from FIG. 5 of the drawings it may be seen that the
interior of the housing 32 is almost completely filled with
lubricating fluid whereby the drive assembly 30 may be operated for
long periods of time under heavy loads without breaking down.
Further, from FIG. 5 of the drawings it may also be seen that water
is readily taken into the inlet neck 58 of the housing 52 and it is
to be understood that the rear end of the housing 52 necks down to
the discharge neck or nozzle 66 in order to provide a means for
accelerating the discharge of water from the nozzle 66 whereby a
greater speed is possible. Also, the housing 52 may be readily
removed from access to the propeller 62 whereby the latter may be
changed as desired according to the load and power of the boat
10.
When the shaft 40 is driven in reverse, the propellers 62 pull
water inwardly through the rear of the housing 52 and discharge the
water in a forward and downward direction through the inlet 58. Of
course, when the hull 10 is standing still or moving slowly in
reverse, the level of the water is approximately that illustrated
in FIG. 1. On the other hand, when the hull is moving forward at
speed, the level of the water immediately rearward of the transom
is substantially coplanar with the undersurfaces of the bottom 12
adjacent the transom. Accordingly, when the hull is moving forward
at speed, it draws very little water, on the order of 4 inches.
The foregoing is considered as illustrative only of the principles
of the invention. Further, since numerous modifications and changes
will readily occur to those skilled in the art, it is not desired
to limit the invention to the exact construction and operation
shown and described, and accordingly all suitable modifications and
equivalents may be resorted to, falling within the scope of the
invention.
* * * * *