Motor scooter

A motor scooter having a seat mount and a foot rest floor contains a fuel tank of limited height but expensive horizontal dimensions positioned beneath and in close proximity to the foot rest floor in order to advantageously lower the effective center of gravity of the vehicle and to enable the use of a fuel tank having increased capacity.

BACKGROUND OF THE INVENTION 
The present invention relates to motor scooters and, more particularly, to 
motor scooters of the two-wheel or three-wheel type having a foot rest in 
front of and below the seat and a fuel tank assembly for installation 
therein. 
A motor scooter provided with a fuel tank having a portion disposed under 
the foot rest floor in front of the seat is disclosed in Japanese Patent 
Laid-Open No. 60-154969. 
Fuel tanks for motor scooters contain fuel and are a comparatively large 
and heavy component as compared with the other accessories of the motor 
scooter. Therefore, the fuel tank must meet the following conditions in 
mounting the same on the motor scooter: 
(1) it must not degrade the running performance of the motor scooter; 
(2) it must be protected from damage; 
(3) it must not interfere with the other functional parts of the vehicle; 
(4) it must have an adequate capacity; and 
(5) it must not detract from the space utilizable as a luggage compartment 
nor the external appearance of the motor scooter. 
It is accordingly desirable that the fuel tanks employed in motor scooters 
be of a simple construction and capable of meeting the foregoing requisite 
conditions. 
In this known motor scooter, the fuel pump must be disposed remote from the 
engine of the power unit, which is located in the rear portion of the 
motor scooter, a comparatively long fuel supply pipe is necessary for 
connecting the fuel pump to the engine. Still further, the components of 
the fuel supply system, such as the fuel pump, must be provided under the 
foot rest floor under limited conditions of arrangement, which makes 
compact construction of the fuel supply system difficult. 
The present device has accordingly been invented to ameliorate the 
aforementioned disadvantages of the prior art. 
SUMMARY OF THE INVENTION 
To achieve the foregoing object, the present invention provides a motor 
scooter having a frame, front and rear wheels suspended on the frame, a 
body cover covering the frame and having a seat mount, a foot rest 
positioned in front of the seat mount, a fuel tank assembly disposed below 
the foot rest and a luggage compartment positioned below a seat on the 
seat mount and adjacent to the rear portion of the fuel tank at the front 
lower portion of the seat mount. 
The horizontal flat fuel tank can be disposed within a dead space under the 
foot rest floor of the body panel, and the fuel tank is protected from 
damage by the right and left frame pipes of the motor scooter frame 
structure. Furthermore, since the fuel filling mouth is formed in the rear 
portion of the fuel tank, a flat wide area is available for the foot rest 
floor. Still further, the upper wall of the fuel tank inclining toward the 
front suppresses the disturbance of the surface of the fuel contained in 
the fuel tank by the vibrations of the motor scooter. 
In the motor scooter of the invention a center cover rises from the rear 
end of the foot rest floor to the front end of the bottom of the seat so 
that the fuel filling mouth is located within the space behind the center 
cover. A fuel strainer and a fuel pump are disposed beside the fuel 
filling mouth. 
According to the present device, the fuel filling mouth does not project 
from the upper surface of the foot rest floor and, hence, an increased 
area is available for resting the feet. The driver is, thereby, allowed to 
drive the motor scooter in a comfortable position. The arrangement of the 
fuel filling mouth, the fuel strainer and the fuel tank side-by-side 
widthwise of the motor scooter within a space behind the center cover 
enables a compact arrangement of the components of the fuel supply system 
within the same space. Furthermore, the disposition of the fuel filling 
mouth, the fuel strainer and the fuel pump on a level above the foot rest 
floor enables the provision of a fuel tank having an increased capacity 
under the foot rest floor. Still further, since the fuel pump is disposed 
near the engine, the fuel pump can be connected to the engine by a fuel 
supply pipe having a reduced length. 
Moreover, according to the present invention, a heat insulating member can 
be provided between the fuel pump and the engine to insulate the fuel pump 
from the heat generated by the engine, which enables the further reduction 
of the length of the fuel supply pipe interconnecting the fuel pump and 
the engine. 
For a better understanding of the invention, its operating advantages and 
the specific objectives obtained by its use, reference should be made to 
the accompanying drawings and description which relate to a preferred 
embodiment thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 is a longitudinal sectional side elevation showing an essential 
portion of a motor scooter incorporating a fuel supply system according to 
a first preferred embodiment of the present device. A steering head 3 is 
formed in the front portion of the motor scooter. A front wheel 2 is 
suspended on the steering head 3 below the same by a front fork 1, and a 
handle (not shown) is provided on the upper end of the steering head 3. A 
floor section 5 is formed in the lower portion of the body between the 
steering head 3 and a seat 4 is provided in the rear portion of the body. 
The steering head section and the seat section are interconnected by a 
substantially U-shaped main frame 6. As shown in FIG. 7, the main frame 6 
is composed of a head pipe 7, a down pipe 8 having an upper end fixed to 
the head pipe 7 and extending obliquely downwardly, a pair of frame pipes 
9 (a right frame pipe 9r and a left frame pipe 9l) branched from the lower 
end of the down pipe 8 respectively to the right and left and having each 
a horizontal portion extending toward the rear along the floor section 5, 
a rising portion rising from the rear end of the horizontal portion 
upwardly and a rear portion extending toward the rear from the upper end 
of the rising portion, and cross members extending between and 
interconnecting the pair of frame pipes 9r and 9l. 
A bracket 10 is welded to the frame 6 at the junction of the horizontal 
portion and the rising portion of the frame pipe 9 so as to extend 
rearwardly. A retractable stand 11 is joined pivotally to the extremity of 
the bracket 10 by a pivot shaft 12, and a lever 13 is joined pivotally to 
the middle portion of the bracket 10. The lever 13 has an arm 13a 
extending toward the rear. The arm 13a is joined pivotally at the rear end 
thereof to a power unit 14. An engine 15 is mounted integrally on the 
power unit 14 in the front portion of the same, and a rear wheel 16 is 
supported rotatably on the power unit 14 in the rear end of the same. A 
shock absorber 17 is extended between the rear end of the power unit 14 
and the frame pipe 9. The other arm 13b of the lever 13 has a cylindrical 
shape. The upper end of the arm 13b is fitted in a cylindrical rubber 
stopper 19 attached to a cross pipe 18 interconnecting the frame pipes 9r 
and 9l. The vertical movement of the power unit 14 is controlled 
elastically by the stopper 19. 
A helmet container 22 is disposed above the power unit 14 and is fixed to 
brackets 20 and 21 attached to the frame pipe 9. The seat 4 is mounted on 
and fastened to the helmet container 22. 
A helmet 23 is contained in the helmet container 22, and a kit box 24 is 
formed in the rear section thereof. 
The chassis principally formed by the main frame 6, is covered with a body 
cover 25. The body cover 25 has a foot rest floor 26 extending over and 
covering the frame pipes 9 in the floor section 5, an under cover member 
27 extending under and covering the lower and side surfaces of the frame 
pipes 9, and a center cover 28 rising from the rear end of the foot rest 
floor 26 to the front end of the bottom of the seat 4. As shown in FIG. 8, 
the foot rest floor 26 having the shape of a flat plate, extends between 
the front and rear ends of the floor section 5 and has an arcuately formed 
rising wall 29 in the rear portion thereof. A crescent-shaped partition 
wall 30 extends toward the rear from the rear surface of the rising wall 
29 in a plane above the plate-shaped front portion of the foot rest floor 
26. 
The upper edge of the rising wall 29 is joined to the lower edge of the 
center cover 28. As shown in FIG. 8, the center cover 28 is divided into 
two parts, namely, a right center cover member 28r and a left center cover 
member 28lalong the center line of the chassis. Side covers 31r and 31l, 
respectively, for covering the opposite sides of the chassis under the 
seat 4 are formed integrally with the right and left center cover members 
28r and 28l respectively. A recess 32 is formed in the lower portion of 
the right center cover member 28r and a recess 33 is formed in the 
right-hand side of the rising wall 29 so as to correspond to the recess 
32. When the center cover 28 is joined to the rising wall 29, a 
rectangular window is formed by the recesses 32 and 33 in the right-hand 
lower portion of the center cover 28. The window is covered with lid 34 
connected by hinges 34' as shown in FIG. 2. 
A fuel tank 35 is disposed within a space enclosed by the foot rest floor 
26 and the under cover 27 between the frame pipes 9r and 9land is fastened 
to brackets 36 fixed to the fame pipes 9r and 9l via bolts 36'. The upper 
surface 35a of the tank 35 is provided in its rear portion with a bulge 
35b. The bulge 35b is closed in a dead space formed between the container 
22 and the rising wall 29. As best shown in FIG. 8, a fuel filling mouth 
37 is formed in the bulge 35b on the upper wall of the fuel tank 35. A 
fuel outlet pipe 39 is inserted through the upper wall of the fuel tank 35 
in the fuel tank 35 at a position on the left side of the fuel filling 
mouth 37. The fuel filling mouth 37 projects upward toward an opening 40 
formed in the partition wall 30 and opens opposite the window formed of 
the recesses 32 and 33. Accordingly, fuel can be filled in the fuel tank 
35 through the fuel filling mouth 37 after opening the lid 34. 
As shown in FIGS. 9 and 10, a fuel strainer 41 and a fuel pump 42 are 
disposed above the partition wall 30 on the left side of the fuel filling 
mouth 37 and are fastened to a bracket fixed to the main frame. A fuel 
supply pipe 38 connected at one end thereof to the fuel outlet pipe 39 is 
extended upwardly through the partition wall 30 and is connected to the 
inlet of the strainer 41. The outlet of the strainer 41 is connected to 
the suction port of the fuel pump 42 by a suction pipe 43. The fuel pump 
42 is of a negative pressure type operated by the negative pressure 
generated by the engine 15. Indicated at 44 is a negative-pressure pipe 
for applying a negative pressure generated by the engine 15 to the fuel 
pump 42. The fuel discharged by the fuel pump 42 is fed through a fuel 
feed pipe 45 to a carburetor C, which in turn feeds the fuel to the engine 
15 (FIG. 1). A partition wall member 46 is provided behind the fuel 
filling mouth 37, the strainer 41 and the fuel pump 42 arranged over the 
partition wall 30. The front wall of the helmet container 22 extends 
behind and along the partition wall member 46. The lower portion of the 
helmet container 2 extends below the partition wall member 46 and is 
fastened to the bracket 20 with a bolt 47. 
In this embodiment thus constructed, since the fuel tank 35 is formed of a 
flat shape so as to be disposed in a horizontal position under the foot 
rest floor 26 of the body panel 25, the dead space under the body panel 25 
can be utilized for accommodating a fuel tank 35 having a comparatively 
large capacity. Furthermore, since the fuel tank 35 is disposed between 
the right and left frame pipes 9 of the frame 6, the fuel tank 35 can be 
guarded from obstacles. The fuel filling mouth 37 of the fuel tank 35 
disposed under the foot rest floor 26 projects into the space behind the 
center cover 38 and does not project above the foot rest floor 26, and 
hence the foot rest floor 26 has a wide flat upper surface. Since the fuel 
filling mouth 37, the strainer 41 and the fuel pump 42 are disposed in a 
compact arrangement within the space enclosed by the partition wall 30, 
the center cover 28 and the partition wall member 46 in an upper position 
behind the foot rest floor 26 and near the engine 15 of the power unit 14, 
the fuel supply system is simplified and the length of the fuel supply 
piping is reduced. Furthermore, such an arrangement of the fuel filling 
mouth 37, the fuel strainer 41 and the fuel pump 42 further enhances the 
provision of a large tank having an increased capacity as the fuel tank 
35. Still further, the front wall of the helmet container 22 extends along 
the partition wall member 46 to a position below the partition wall member 
46 to shield the fuel pump 42 and the associated components from the 
engine 15. Thus, the helmet container 22 functions as a heat insulating 
member which intercepts the heat radiated from the engine 15. 
In the embodiment of FIG. 5, the junction of the frame 6 and the linkage 13 
for supporting the front end of the power unit 14 in the second embodiment 
is higher than that in the first embodiment, and the fuel tank 35 in the 
second embodiment has a rear extension 35'. The fuel tank 35 is disposed 
with the rear extension 35' received in a dead space under the linkage 13. 
Thus, the fuel tank 35 in the second embodiment has a capacity greater 
than that of the fuel tank 35 in the first embodiment. As shown in FIG. 5, 
the upper wall of the fuel tank 35 is downwardly inclined in a state where 
the main stand 20 is retracted, and, hence, it is possible to make the 
fuel spilt in filling fuel in the fuel tank 35 with the rider seated on 
the seat to flow toward the front. Thus, the second embodiment exerts 
essentially the same functions and effects as those of the first 
embodiment. 
FIG. 11 shows a fuel supply system according to a third embodiment of the 
present device. In this embodiment, the helmet container 22 is disposed in 
the upper section of the rear portion of the chassis, and hence the helmet 
container 22 does not function as a heat insulating member. Accordingly, a 
cross plate 48 is extended in front of the engine 15 between the right and 
left frame pipes 9 of the chassis to intercept the heat radiated from the 
engine 15. The cross plate 48 serves also as a frame reinforcing member. 
FIG. 12 shows a fuel supply system according to a third embodiment of the 
present invention. A motor scooter incorporating the fuel supply system in 
the third embodiment is equipped with a horizontal engine 15 having a 
horizontal cylinder 15a extending to the front. A cross plate 49 having an 
L-shaped cross section is extended between the right and left frame pipes 
9 so as to cover the front surface and upper surface of the cylinder 15a . 
The cross plate 49 serves as a heat insulating member for insulating the 
fuel pump 42 from heat, and as a member for supporting a helmet box 22. 
FIGS. 13 to 17 illustrate a motor scooter employing a fuel supply system 
according to yet another embodiment of the invention wherein like 
components are identified by numeral designations corresponding to those 
employed in the other figures. According to this motor scooter 
organization the fuel tank 35 is located beneath the foot rest floor 26 as 
in the previously described embodiments. The fuel filling mouth 37 of the 
earlier embodiments is replaced by an elongated fuel filler pipe 60 that 
communicates with the front portion of the fuel tank 5. The pipe 60, which 
may be formed of a flexible material, extends vertically along the head 
pipe 7 within the front portion of the body cover 25. A fuel inlet 61 
covered by a closure cap 2 is disposed at the distal end of the pipe 60. 
Access to the fuel filler inlet 61 is obtained by means of an opening 63 
formed in the body cover 25, which opening is closed by a hinged lid 64. 
In this motor scooter organization the case body 66 of an air cleaner 65 is 
disposed in the dead space behind the lower portion of the center cover 
member 28, which is provided with an opening 67 closed by a hinged closure 
cover 68 for accessing the air cleaner. As shown, the air cleaner case 
body 66 has a lid 9 for holding an air cleaner element 70 having suction 
ports 71 provided therein. The outlet port 72 of the air cleaner 65 is 
connected to the carburetor C via an air chamber 73 by the air conduit 
pipe 74. 
The motor scooter of this embodiment contains a luggage container 22' for 
housing a pair of helmets indicated as H1 and Hz The luggage container 22' 
is formed by substantially rectangularly disposed side walls and is 
elongated in the front-to-back longitudinal direction The top of the 
container 22' is open for accessing the interior thereof. The top opening 
is closed by the seat 4 which is attached to the container for pivotal 
movement and which may be locked in the closed position by a locking 
mechanism 75. 
The luggage container 22' is attached to cross members 76 and 77 between 
the frame pipes 9l and 9r by means of bolts 78. At about the longitudinal 
midpoint of the container the bottom wall is recessed as at 79 to form a 
channel-like cross section protruding into the container interior across 
the bottom wall 80. This protrusion conveniently accommodates the cross 
member 77 and also assists in positioning the helmets H1 and Hz within the 
compartment. By means of the arrangement the shock absorber 17 has ample 
freedom of movement for expansion and contraction caused by the 
up-and-down pivotal movement of the power unit 14. 
The side walls of the container 22' are covered by the cover 28. An 
auxiliary lid 81, pivoted by a hinge 82, is provided on the upper portion 
of the container beneath the rear end of the seat 4. The lid 81 closes the 
rear end of the compartment 22', as well as a compartment formed by cover 
28 for housing a tank 83 for lubricating oil. Alternatively, instead of 
the auxiliary lid 81, the seat 4 can be extended rearwardly as shown by 
the phantom line 4'. 
The forward end 84 of the rear fender is integrally formed on the rear side 
of the compartment 22'. The rear end 86 of the fender is attached to the 
forward end by bolts 85. A tail light mounting 87 is provided on the rear 
end 84 of the fender. 
As is apparent from the foregoing description of the present invention, 
there is provided a fuel tank assembly for a motor scooter having a large 
luggage container adjacent to the fuel tank whereby the front lower 
portion of the container is adjacent to the rear of the fuel tank so that 
both the fuel tank and the luggage container can be provided with 
increased capacity and the center of gravity of the motor scooter can be 
lowered. An accommodating space for the functional parts of the fuel tank 
assembly or of the engine can be disposed above the fuel tank and below 
the front lower portion of the luggage container behind the center cover 
of the seat mount. A fuel tank which is essentially horizontally flat is 
disposed under the foot rest floor with the fuel filling mouth thereof 
projecting either into a space behind the center cover or to an elevated 
position in the forward portion of the front cover. A fuel strainer and a 
fuel pump can be disposed beside the fuel filling mouth within the space. 
Alternatively, the space can be occupied by an air cleaner, or the like. 
Accordingly, the foot rest floor can be formed in a wide, flat surface, 
the fuel supply system can be simplified, the length of the fuel piping 
can be reduced, and a large fuel tank having a large capacity can be 
protectively disposed between spaced frame members under the foot rest 
floor. 
Furthermore, according to the present device, since a heat insulating 
member is provided between the fuel pump and the engine, the fuel pump can 
be disposed sufficiently near the engine without entailing adverse 
influence of the heat radiated by the engine on the fuel pump, and thereby 
the piping connecting the fuel pump to the engine can be simplified and 
the length of the piping can be reduced. 
Still further, since the upper wall of the fuel tank is inclined downwardly 
toward the front and is in close proximity to the foot rest floor, the 
center of gravity of the motor scooter is lowered, and the disturbance of 
the fuel due to the vertical vibrations and acceleration of the motor 
scooter is suppressed to improve the running performance of the motor 
scooter. 
Moreover, since the fuel filling mouth is provided either in the rear 
portion of the fuel tank or the forward portion thereof, the foot rest 
floor can be formed in a flat shape so that the rider is able to put his 
feet properly on the foot rest floor. 
It should be further understood that, although preferred embodiments of the 
invention have been illustrated and described herein, changes and 
modifications can be made in the described arrangements without departing 
from the scope of the appended claims.