Note: Descriptions are shown in the official language in which they were submitted.
;~044350
SPECIFICATION
DEVICE USED IN JET-PROPELLED GLIDING BOATS FOR
PREYENTING FLOATING OBSTACLES FROM BElNG DRAWN IN
BACKGROUND OF THE INVENTION
Small-sized gliding boats of the jet-propelled type
arranged for a slngle person to rlde In a standlng posture
or some persons to ride ln a seated posture have
lncorporated thereln a jet-propelling devlce (or water ~et
pump) adapted to be drlven for rotatlon by an engine mounted
on the boat.
Such ~et propelllng device is deslgned to draw water
through a water lntake port formed in the bottom surface of
the bost body, acceleratlng said water by an Impeller
Installed In a water Intake duct (or pump case) to spout It
rearwardly of the boat body, the reactlon force serving as
the propelllng force for the boat body. Thus, the jet
propelllng devlce has the danger of drawing not only water
but also garbage, seaweed, fishlng llnes and other var~ous
floatlng obstacles. To~prevent such obstacles from belng
drawn In, as found In Japanese Patent PublIcatlon No.
~8356/1986, and Japanese Utallty Model Publlcatlon Nos.
28640/1980 and 317~9/1979, a lattice called scope gate or
grate is attached to the bottom surface of the boat body to
cover sald water Intake Port.
Z044~50
.
To prevent floating obstacles from being drawn in, the
number of partitlon bars could be Increased to partltion the
interior of the lattlce more finely; It may be sald that the
more flnely it ls partltloned, the greater the effect
attained. In that case, however, the amount of water that
can be drswn in through the water intake port would also
decrease, and the water flow would be bubbled or agltated.
Such phenomenon becomes particularly noticeable when the
boat body Is turning. The reason is that durlng the turning
of the boat body, the natural flow of water from the water
intake port toward a water intake duct Is held back or
dashes hard agalnst the partition bars. As a result, a
cavitation phenomenon takes place In the water Intake duct
(pump case), corrodlng the Impeller or causing the loss of
propelllng energy.
Further, the more finely the Interlor of the lattlce of
the scope gate is partltloned, the greater the welght of the
scope gate It~elf. Furthermore, flner partltionlng makes it
less easy to visually inspect the lnterior of the water
Intake duct from the water Intake port. More particularly,
If a floating obstacle enters the water intake duct and
twlnes Itself around the impeller or the lmpeller shaft, the
operatlon for removal thereof cannot be performed easily and
efflclently.
If the scope gate Is made of an opaque metalllc
materlal, thl~ drawback Is partlcularly notlceable. And
2044350
before the aforesaid visual lnspection can be made, the
boat body must be turned over to direct Its bottom surface
upward; thls operation requires heavY labor.
SUMMARY OF T~IE IN~ENTION
The present Inventlon has been accompllshed to solve
these problems, and an ob~ect thereof is to provide an
arrangement whereln to partltlon the water intake port
formed in the bottom surface of the boat body, the scope
gate for preventlng floating obstacles from being drawn In
Is made in lattice form, comprising a pair of attaching
seats by which it is attached to the boat bodY and a palr of
longitudinal partition walls extending parallel with the
travel center line of the boat body to bridge the space
between said seats, the latter halves of said longitudlnal
partition walls extending downward by a fixed amount beyond
the bottom surface of the boat body, a transverse partition
wall disposed in said extending portions in an Inclined
state sloping rearwardly upward at a fixed angle, the lower
surface of sald transverse partition wall extending downward
beyond the lower surface of the boat body, thereby arresting
floating obstacles to prevent them from entering the water
intake port In the boat body.
Another ob~ect is to provide an arrangement wherein the
transverse partition wall bridges the space between
longitudlnal partltion walls in such a manner as to deflne a
20~4350
larger space between It and the front attachlng seat and a
smaller space between it and the rear attachlng ~eat and is
disposed In an Incllned state sloplng rearwardly upward at a
fixed angle, whereby water is drawn In wlth no resistance
through the water intake port such that the flow llnes of
water taken from the front larger space lnto the water
intake port is dense and the flow rate is hlgh whlle the
flow lines of water taken from the rear smaller space into
the water intake port is sparse and the flow rate is low,
and the pressure in the smaller space Is negative relative
to that in the larger space, with the result that floating
obstacles once arrested by the lower surface of the
transverse partltlon wall are hardly drawn from the smaller
space located therebehind into the water Intake port and
Instead they are moved rearwardly of the boat body by the
actlon of water flowing along the bottom surface of the boat
body.
That is, the lattice of the scope gate Is not of flnely
partitloned constructlon, 60 that water Is smoothly guided
from the water lntake port In the boat body Into the water
Intake duct wlthout being excessively held back or being
caused to bubble or belng agltated, thus elImlnatlng the
posslblllty of cavltatlon taking place In the water Intake
duct, whlle allowlng vlsual inspectlon of the Interlor of
the water Intake duct easily from outside and preventing
garbage, seaweed, flshlng llnes and other varl 0U8 floatlne
Z04~350
obstacles frnm being drawn ln together wlth water.
Such object can be attalned by providlng an arrangement
whereln the longitudinal partitlon wal 18 of the 6cope gate
extendlng along the travel center line of the boat body are
reduced In number to unlty, substantlally the latter half of
such single longitudlnal partition wall extending downward
by a flxed amount beyond the bottom surface of the boat
body, the extending latter half being blfurcated and sloping
rearwardly upward at a fixed angle to provlde a transverse
partltion wall, the front ends of the branches belng
contlnuou6 with the rear attachlng seat, with the result
that a palr of larger water intake spaces are defIned
between the transver6e partltlon wall and the front
attachlng seat and a smaller water Intake space Is deflned
between the transverse partltion wall and the rear attaching
seat.
The smaller water Intake space Is poslttoned rearwardlY
of the lower surface of the transverse partltlon wall where
floatlng obstacles are once arrested, and the same as the
above may be sald about the Interrelatlonshlp between the
flow llnes and flow rate of water drawn therefrom into the
water Intake port and those of water drawn frnm the larger
spaces Into the water Intake port; thus, floatlng obstacles
once arrested are posltlvely pushed away rearwardly of the
boat body along the bottom surface of the boat bndy by the
water energy. Accordlng to such arrangement, the normal
Z044350
water drawing action at the water Intake port of the boat
body can be made further smooth and the scope gate ltself
can be further simpllfled.
Another obJect of the lnventlon is to Provlde an
arrangement wherein the transverse partition wall is V- or
U-shaped as seen in a bottom vlew such that it graduallY
extends forward as its center located on the travel center
line of the boat body is approached, whereby floating
obstacles once arrested by the lower surface of said
transverse partition wall are efflciently pushed away
rearwardly in two diverging directions so that they are
prevented from entering the water intake port.
A further obJect of the invention is tn provide an
arrangement wherein the scope gate Is made by inJection
molding of a transparent or translucent engineering plastic
material so that thls lnJection moldlng, coupled wlth the
employment of a construction in whlch the Interior of the
lattice is not flnely partitioned, allows the Interlor
thereof tn be seen easily from outside, while even if
floating obstacles should twine themselves around the
impeller or the propeller shaft in the water intake duct,
they can be efficiently removed, the scope gate being light
in weight and adapted for mass production.
- Other ob~ects as well as the arrangement of the
Invention wlll become apparent from the following detailed
description of preferred embodiments.
--6--
204~3so
BRIEF DESC~IPTION OF THE DRAWINGS
Fig. 1 is a schematic side view of a jet-propelled
gliding boat with the present invention applied thereto:
Fig. 2 is an enlarged bottom view showing the rear
portlon of the boat body
Fig. 3 is a sectional view taken along the line 3-3 in
Fig. 2;
Flgs. 4 and 6 are a perspectlve view and a bottom vlew
of a scope gate;
Fig. 6 Is an enlarged sectlonal vlew taken along the
llne 6-6 in Fig. 6;
Flg. 7 Is an enlarged sectlonal vlew taken along the
llne 7-7 In Flg. 5;
Flg. 8 18 a perspectlve vlew of a spacer;
Flgs. 9 and 10 are a perspective vlew and a bottom vlew
~howing a first modlfled embodiment of a scope gate;
Flg. 11 Is an enlarged sectlonal vlew taken along the
llne 11-11 In Flg. 10;
Flgs. 12 and 13 are a perspectlve view and a bottom view
showlng a second modlfied embodlment of a scope gate;
Ftg. 14 18 a sectlonal vlew taken alnng the line 14-14
In Flg. 13; and
- Flg. 15 Is an enlarged sectlonal vlew taken along the
llne 16-16 ln Flg. 13.
.
~044350
DETAILED DESCRIPTION OF THE PRE~ERRED EM~ODIMENTS
The concrete arrangement of the Inventlon wlll now be
descrlbed in detall wlth reference to the drawlngs. In Fig.
1 schematlcally showlng a ~et-prnpelled small-slzed glldlng
boat in its entlrety, the character A generally denotes a
boat bodY made of fIber-reinforced plastlc (FRP), sald boat
body belng of hollow sealed constructlon Including a front
reglon deflned as an englne room 10 and a rear reglon with
~ts upper surface defIned as a floor deck 11 for a driver to
ride In a standing posture. In some cases, the middle area
of the floor deck 11 wlll be provided wlth a seat for a
driver. The numeral 12 denotes an englne contained in the
engine room 10 for drlvlng a jet-propelllng devlce (water
~et pump) B through a propeller shaft 13 to impart a
propelling force to the boat body A.
The propeller shaft 13 extends along the travel center
llne O-O of the boat body A to a posltlon below the floor
deck 11 and Is connected at Its front end to the crank shaft
(not shown) of the englne 12 through a clutch 14.
Integrally rotatably connected to the-rear end of the
propeller shaft 13 are an Impeller 16 and gulde vane~ l6.
The numera1 17 denotes a water Intake duct servlng as a pump
ca~e for recelvlng the Impeller lfi and,gulde vanes 16, sald
water Intake duct belng dlsposed below the floor deck 11,
wlth Its front slde provldlng a water Intake port 18 whlch
opens in the mlddle of the bottom surface of the boat body
2044350
A.
~ hen the lmpeller shaft 13 is drlven for rotatlon, Its
Impeller 15 draws water through the water intake port 18.
In the water Intake duct 17, the water drawn ls accelerated
and forced rearward by the Impeller 16 and Its flow Is
regulated by the guide vanes 16, thereupon it is spouted out
through a steering nozzle 19 whlch opens ln the stern of the
boat body A; the reaction to the spouting force advances the
boat body A.
The steerlng nozzle 19 ls manually controlled from the
floor deck 11 to change Its direction, whereby the boat body
A can be ~teered. In additlon, the numeral 20 denotes a
pump case cover attached to the middle reglon of the bottom
~urface of the boat body A.
Since there Is a danger of garbage, seaweed, fishlng
lines and other various floating obstacles being drawn in
together wlth water through the water intake port 18, a
scope gate C for preventing entry thereof 18 attached to the
mlddle reglon of the bottom surface of the boat body A to
cover the water intake port 18, as shown in Figs. 2 and 3.
In the present Inventlon, the scope gate G is made of a
llght alloy or tranæparent or translucent polYcarbonate
resin, polyacetal resin or other thermoplastic englneering
plastlc materlal preferably havlng hlgh bendlng elastlcitY
Into the fnrm of an elongated lattlce.
In ~Ig~. 4 through 7 showlng a baslc embodlment of a
_g_
Zl~4~;~5~)
scope gate G, the numerals 21 and 22 denote a palr of
attaching seats having a wldth w2 smaller than the width wl
of sald water intake port 18. The front attachlng seat 21
has a palr of bolt receiving holes 23 on opposlte sldes,
whlle the rear attachlng seat 22 ls centrally formed with a
bolt receiving hole 24 whlch preferably ls elongated in the
longltudlnal dlrectlon. The number and dlsposltlon of bolt
receiving holes 23 and 24 may be freely changed in
connection with the boat body A.
The attaching seats 21 and 22 are applied at their flat
surfaces to the bottom surface of the boat body A and then,
as shown in Figs. 2 and 3, fixed thereto by a plurality of
stud bolts 26 and 26 so that the scope gate G can be removed
or exchanged.
The open edges of the attaching seats 21 and 22 of the
scope gate G opposed to the interior of the lattice are
.
formed as slope surfaces rearwardly ascending at
glven angles ~ and ~ wlth respect to the horlzontal surface.
Thus, water can be smoothly drawn from the water lntake port
18 of the boat A into the water Intake duct wlthout
disturbing water.
The numeral 27 denotes a pair of flow regulating
longltudlnal walls spanning the space between the attaching
seat 21 and 22 and extending parallel with the travel center
line 0-0 of the boat body A to partitlon the water Intake
port 18 of the boat body A wlth the lateral surfaces thereof
--10--
2044350
being approxlmately orthogonal to the attaching surfaces of
said seats 21 and 22.
In this sense, the walls have been referred to as the
"longltudinal partltlon walls". By maklng the entire scope
gate G by iniection molding of the aforesald plastic
material havlng hlgh bending elastlcity, the longitudinal
partition walls 27 can be transversely.deformed as if they
were plate springs durlng the turning of the boat body Q.
Thus, during the turnlng of the boat body Q, the
longltudlnal partition walls 27 of the scope gate C are
sub~ected to the water pressure acting thereon and are
thereby elastlcally deformed transversely to and fro, thus
allowlng water to flow without being held back or disturbed;
thus, water Is smoothly drawn in through the water intake
port 18. For this reason, the cavltation In the water
Intake duct 17 i~ effective!y suppres~ed.
Further, the cross-sectlons of the longltudlnal
partitlon walls 27 are preferably ln the form of a bas1c
trlangle or trapezold wlth Its thlckne6s gradually
decreaslng upward, as suggested In Flg. 7. That Is, the
surfaces of the longitudlnal partltlon walls 27 are formed
a~ slope surfaces wlth the thlckness gradually decreaslng
upward.
- Wlth the arrangement thus made, even If the boat body Q
Is tllted durlng turnlng, the longltudinal partltlon walls(2
o the scope gate C Integral therewlth are also tllted such
--11-
204435~)
that the wall surfaces are orthogonal to the water surface,
w1th the result that the holding back and disturbance of
water are effectively suppressed, and substantiallY the same
of thc boat bodr A
amount of water as during stralght travel/ls smoothly drawn
from the water Intake port 18 into the water Intake duct 17.
When the longitudinal partltlon walls 27 are seen
laterally of the boat body A, as Is clear from Flgs. 4 and
6. thelr upper surfaces are f1at, whereas thelr lower
surfaces are V-shaped gradually downwardly pro~ectlng as the
approxlmately intermedlate reglons a are reached.
That ls, the lower surfaces of the approxlmately front
halves of the longltudlnal partltlon walls 27 are forwardly
upward slope surfaces connected flush to the lower surface
of the froht attachtng seat 21, whlle the lower surfaces of
the remalnlng rear hslves are rearwardly upward slope
~urfaces connected flush to the lower surface of the rear
attaching seat 22; thus, each Intermedlate reglon a where
the slope surfaces cross each other projects downward by the
greatest amount. The character r suggests the crosslng
angle between the forwardly and rearwardly upward slope
surfaces.
Thus, In the case where the scope gate G Itself Is
Integrally made of sald plastlc materlal, the Intermedlate
r¢glons a remotest from the palr of attachlng seats 21 and
22 can be phys~cally reinforced to be free from dama~e
thereto. ~urther, the front halves of the longltudlnal
-12-
. - ............. .. . ..
X044350
partltion walls 27 have their lower surfaces deslgned to
define forwardly upward slope surfaces therefore, the boat
body A can be given lift by water acting on said surfaces.
At any rate, as is clear from Fig. 3, the scope gate C
of the present invention is adapted to be fixed at sald
attaching seats 21 and 22 to the bottom surface of the boat
body 9 such that the rear portions of the longitudinal
partitlon walls 27 proJect by a flxed amount h downward
beyond the lower surfsce of the boat body A.
In that case, a spacer 28 shown In Fig. 8 ls preferably
interposed between the rear attaching seat 22 and the bottom
surface of the boat body A so as to adjust said amount of
pro~ectlon h.
That is, the spacer 28 Is shaped to correctly fit on the
rear attachlng seat 22 of the scope gate G; thus, it is
applled to the rear attachlng seat 22 for attachment to the
bottom surface of the boat body A by sald stud bolt 26
through a communlcation hole 29 alIgned wlth a bolt
recelvlng hole 24, thereby increaslng the amount of
proJectlon h. It Is posslble to decrease the amount of
proJectlon h by removlng the spacer 28.
The numeral 30 denotes a transverse partltlon wall
transversely extendlng between the Intermedlate portlons of
the longltudlnal partltlon walls 27, thereby dlvldlng the
Interlor of the lattlce of the scope gate G Into a front,
larger water Intake space Sl and a rear, smaller water
-13-
X0~4350
intake space S2. That Is, the larger space Sl IB located
between the front attaching seat 21 and the transverse
partition wall 30, while the smaller space S2 Is located
between the transverse partitlon wall 30 and the rear
attachlng seat 22.
In thls case, s~nce the rear halves of the longltudlnal
partltlon walls 27 project downward by a f i xed amount h
beyond the bottom surface of the boat body A, the lower
surface b of the transverse partltlon wall 30 is connected
flush to the lower surfaces of the longltudlnal partltlon
walls 27; thus, as is clear from Flg. 3, it also proJects
downward beyond the bottom surface of the boat body A.
- The surface of the transverse partitlon wall 30 is
formed as a rearwardly upward slope surface crosslng the
horizontal surface at a fixed angle ~ to be substantially
parallel wlth the edges of the openlngs In the attachlng
seats 21 and 22, so that water is smoothly gulded from the
water Intake port 18 of the boat body A Into the water
intake duct 17.
In the case of the bas~c embodiment shown In Figs. 4
through 7, when the transverse partltlon wall 30 is seen
from the bottom surface of the boat body A, the scope gate
G Is curved In v- or U-shape gradually extendlng forward a~
- the center c posltloned on the travel center llne 0-0 Is
approached. Partly because the lower surface b of the
transverse partltlon wall 30 proJects downward beyond the
Z044350
bottom surface of the boat body A as descrlbed above,
floating obstacle6, whlle betng arrested, are moved In two
dlverglng dlrectlons laterally of the boat body A thus,
their accldental entry lnto the water lntake port 18 Is
effectlvely prevented.
So long as the surface of the transverse partition wall
30 is an lncllned surface sloplng rearwardly upward at a
fixed angle ~ wlth lts lower surface b pro~ecting downward
beyond the bottom surface of the boat body A to be exposed,
use may be made of a scope gate G shown in Flgs. 9 through
11, whlch is a first modified embodiment, having a
transver6e partition wall 30a which is straight as seen In a
bottom view and whlch is orthogonal to its longltudinal
partition walls 27a.
In addition, the rest of the arrangement In the first
.shov~n in Fi~. 9 throu~h ll
modified embodlment/is substantlaliy the same as the
embodlment shown In Flgs. 4 through 7; thus, the
correspondlng parts are denoted by llke reference numerals
wlth the letter "a" added thereto, and a detailed
descrlptlon thereof 16 omltted.
Flg~. 12 through l~ 6how a second modlfled embodiment of
a scope gate a accordlng to the present Inventlon, wherein a
~Ingle longltudlnal partltlon wall 27b ls posltloned on the
travel center llne 0-0 of the boat body A and extends
between the attachlng seats 21b and 22b, and the rear end of
sald longltudlnal partltlon wall 27b 16 blfurcated to
2()4435~)
provide a transverse partition wall 30b, the front end~ of
the resulting branches being connected to the oppnslte sldes
of the rear attachlng seat 22b, whereby a smaller space S2
f or water intake is deflned between the transverse partitlon
wall 30b and the rear attachlng seat 22b.
According to this second modlfled embodiment, the larger
space Sl for water intake de$1ned between the front
attaching seat 21b and the transverse partltlon wall 30b Is
bisected by the slngle longltudlnal partltlon wall 27b.
However, regardless of this blsectlon, It stlll opens wlder
than the smaller space S2.
In addltlon, the rest of the arrangement in the
ShOWII in Firs. 12 throu~h 15
second modlfled embodiment/ls substantlally the same as the
embodiment shown In Flgs. 4 through 7; thus, the
correspondlng parts are denoted by like reference numerals
wlth the letter "b" added thereto, and a detalled
descrlptlon thereof Is omitted.
The functlons nf the scope gate C wlll now be descrlbed
on the basls of the baslc embodlment shown ln Flgs. 4
through 7. The scope gate G Is fixed to the bottom surface
of the boat bodY A to partltlon the water Intake port 18 of
the boat body such that substantlally the latter halves of
the palr of longltudlnal partltlon walls 27 prnJect downward
by a flxed amount h beyond the bottom surface of the boat
body A; therefore, a sidesllp preventlng effect (so-called
edglng effect) can be attalned durlng the turnlng of the
-16-
Z04435(~
boat body A. Further, if the boat body runs on shallows or
on drlftlng wood, Its bottom surface wlll not hit the same
and hence damage thereto Is avolded.
Partlcularly, In the Intermedlate portlons of the latter
halves of the longitudinal partition walls 27 pro~ectlng
downward beyond the bottom surface of the boat body A, the
transverse partltlon wall 30 Is disposed to assume an
Inclined state sloplng rearwardlY upward at a flxed angle 9,
whereby the smaller space S2 for water lntake Is defined
between the transverse partltion wall 30 and the rear
attaching seat 22; therefore, wlthout having to flnely
partltion the scope gate G ltself, it can be physlcally
reinforced by the transverse partitlon wall 30 and the entry
nf garbage, seaweed and other varlous floating obstacles
through the water lntake port 18 is prevented.
That is, durlng the use of the boat body A, water flows
along the bottom surface of the boat body A In two
dlrectlons: a dlrection x toward the water intake port 18
and a rearward dlrection y. Partlcularly, as the rear end
edge of the water Intake port 18 is approached, the water
force in the dlrection y increases, 80 that floating
obstacles tend to be gathered at said rear end edge.
In that case, in the present Inventlon the latter halves
of the longitudlnal partltlon walls 27 pro~ect downward by a
fixed amount h and the lower surface b of the transverse
partJtlon wall 30 dlsposed In the Intermedlate portlons of
-17-
44;~51~
said longltudlnal partltlon walls also projects downward
beyond the bottom surface of the boat body A. As a result,
floatlng obstacles once arrested thereat are pushed away
rearwardly of the boat body A by water flowlng In the
dlrectlon y wlthout enterlng the water Intake port 18.
Further, the transverse partition wall 30 disposed in an
Inclined state sloplng rearwardly upward at the flxed angle
divides the interior of the lattlce of the scope gate C
into the front larger space S1 for water intake and the rear
smaller space S2 for water intake therefore, whereas the
flow llnes of water moving in the direction x from the front
larger space S1 are dense and the flow rate is high, so that
the water is drawn Into the water intake port 18 without any
reslstance, the flow llne of water moving In the dotted-line
dlrectlon x from the rear smaller space S2 are sparse and
the flow rate is low and the pressure is negative relative
to that In the larger space S1, wlth the result that
floatlng obstacles once arrested by the lower surface b of
the transverse partition wall 30 are hardly drawn from the
smaller space S2 located therebehlnd into the water Intake
port 18 and Instead they are rellsbly moved rearwardly of
the boat body A by the actlon of water flowing in the
directlon Y.
Such functlon can also be attalned In exactly the same
manner by the first and second modlfied embodiments
descrlbed above. Particularly, as Is clear from the basic
-18-
~044350
embodiment shown in Figs. 4 through 7 and the second
modified embodiment shown in Figs. 12 through 15, if the
transverse partltion wall 30 or 30b are ~- or U-shaPed as
seen from the bottom 6urface of the boat bodY A gradually
extending forward toward the center c located on the travel
center line O-O of the boat body A and are curved in
transversely bifurcated skirt form, then sald floating
obstacles wlll be pu~hed away along such curved 6urface in
two diverglng directions obliquely rearwardly of the boat
body A, so that the entry of said floating obstacles through
the water intake port 18 can be prevented.
At any rate, the interior of the scope gate G of the
present Inventlon does not have to be flnely partitioned and
hence the sufflclent amount of water to be drawn In can be
obta~ned also durlng the turnlng of the boat body A without
dlsturblng the water flow, and yet the entry of floating
obstacles can be rellably prevented. Furthermore, the
requlred arrangement Is very 61mple. The technlcal
slgnlf1cance and value of the inventlon lle In these polnts.
Thus, the Inventlon provldes a devlce used In ~et-
propelled glIdlng boats for preventlng floatlng ob6tacles
from belng drawn In, whereln a scope gate G for preventlng
entry of floatlng obstacles Is attached to a water Intake
port 18 formed In the bottom 6urface of the boat body, and
the water drawn from the water Intake pnrt 18 1~ accelerated
by an Impeller 1~ houoed In a water Intake duct 17 and
--19--
~04ar35~)
spouted rearwardly of the boat body A, sald devlce being
characterized In that as shnwn In the baslc embodlment of
Flgs. 4 through 7 and the first modlfied embodlment of Flgs.
9 through 11, sald scope gate G Is In lattlce form composed
of a palr of attachlng seats 21, 21a or 22, 22a associated
wlth the bottom surface of the boat body A and a pair of
27 and 27a
longltudinal partitlon walls/extending parallel wlth the
travel center llne 0-0 of the boat body A to interconnect
said attachlng seats,
substantlally the latter halves of sald longitudlnal
partltlon walls 27 and 27a pro~ect downward by a fixed
amount h beyond the bottom surface of the boat body A, while
a transverse partltion wall 30 or 30a is dlsposed in the
Intermedlate portlons of the pro~ectlng latter halves to
assume an InclIned state sloping rearwardly upward at a
fixed angle ~, whereby a larger space Sl for water intake Is
deflned between the transverse partitlon wall 30 or 30a and
the front attachlng seat 21 or 21a and a smaller space S2
for water Intake Is defIned between the transverse partltion
wall 30 or 30a and the rear attachlng seat 22 or 22a.
Therefore, as descrlbed wlth reference to Flg. 3, garbage,
seaweed and other floatlng obstacles can be rellably
prevented from enterlng through the water Intake port 18 of
the boat body A; thus, the intended ob~ect can be attained
wlthout dl~turblng the flow of water to be drawn in.
Such functlon and effect can also be attalned In exactlY
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X044350
the same manner by the arrangement descrlbed in Clalm 2
corresponding to the second modlfled embodlment shown In
Figs. 12 through 16. If the arrangement of Clalm 2 Is
employed, slnce the s1ngle longitudlnal partltlon wall 27b
extending along the travel center line 0-0 of the boat body
Q is sufflcient, the normal water drawlng action can be
further enhanced while preventing the entry of floatlng
obstacles; besldes thls, the required arrangement is simple,
a fact which is advantageous for mass productlon.
Further, if the basic embodiment shown in Figs. 4
through 7 and the arrangement described In Clalm 3
correspondlng to the second modified embodiment shown in
Flgs. 12 through 16 are employed, slnce the transverse
partltion wall 30 or 30b Is V- or U-shaped as 6een in a
bottom vlew gradually ProJectlng forward toward the center c
located on the travel center llne O-O of the boat body Q and
1~ curved In transversely bifurcated sklrt form, floatlng
obstacles can be pushed away more efflciently along the
curved surface oblIquely rearwardly of the boat body A;
thu6, thelr entrY through the water Intake port 18 can be
prevented, whlle normal water can be gulded Into the water
Intake port 18 wlthout any reslstance.
In each of the embodlments descrlbed above If the enttre
scope gate G IB Integrally made by InJectlon moldlng of a
tran6parent or translucent thermoplastlc englneerlng plastlc
materlal, as descrlbed In Clalm 4, then thls arraneement,
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~0443S0
coupled wlth the constructlon ln wh~ch the interlor of the
cope gate G is not finely partltloned, allows easily visual
17
inspectlon of the interior of the water Intake duct~-om the
water intake port 18. If floating obstacles should enter
the water intake duct ~nd twlne themselves around the
lmpeller or the propeller shaft, they can be easlly and
efficiently removed. Further, the scope gate is suitable
for mass productlon and ls light in welght.
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