Device to prevent fuel flow from a fuel tank to an engine

A device is used to control the passage of fuel from a fuel tank to an engine. The device comprises a body including a chamber. An inlet member is connected to the body and has an inlet passageway for placing the fuel tank in fluid communication with the chamber. An outlet member is connected to the body and has an outlet passageway for placing the chamber in fluid communication with the motorcycle engine. An element is disposed within the body and movable between a position placing the inlet passageway in fluid communication with the chamber and a position preventing fluid communication between the inlet passageway and the chamber. A lock mechanism is used to secure the element in the position preventing fluid communication between the inlet passageway and chamber to prevent movement of the element to the position placing the inlet passageway in fluid communication with the chamber. Apparatus is disposed within the body for connecting the lock mechanism to the element to move the element when the lock mechanism moves and to prevent movement of the element until the lock mechanism moves.

It is well known that a large number of motorcycles are stolen each year 
from the lawful owners. Several devices have been used to discourage such 
thefts, which generally involve causing the potential thief to spend a 
period of time before the motorcycle can be moved. One example of this 
type antitheft device is the apparatus used to lock the front wheel in a 
turned position to prevent movement of the motorcycle except in a circular 
path until unlocked. Another example of this type antitheft device employs 
a chain passed through the spokes of a wheel with the chain then being 
locked by a padlock. Another example of this type antitheft device employs 
a special padlock which is passed through the drive chain and then locked 
in place. To circumvent these devices, thieves have used a torch to heat 
the lock or chain and a hammer or other device to destroy the lock or 
chain. After the lock has been removed, it is a simple matter for the 
thief to remove the motorcycle from the location where the owner left it, 
such as by riding the motorcycle away. By heating the lock and breaking 
it, the time spent by an experienced thief is minimal and therefore not 
much of a deterrent. 
Accordingly, it is an object of the present invention to provide apparatus 
than can not be easily removed from a motorcycle by using heating 
apparatus or by using a striking instrument on locking apparatus without 
the possibility of substantial damage to the motorcycle or thief. 
Further, it is an object of the present invention to provide apparatus that 
inhibits a thief from starting the motorcycle engine after the apparatus 
is forcibly removed from the motorcycle. 
Further, it is an object of the present invention to provide apparatus that 
inhibits any unauthorized use of a vehicle by preventing fuel flow from 
the vehicle's fuel tank to the vehicle's engine until the apparatus is 
unlocked. 
Further, it is an object of the present invention to provide a motorcycle 
antitheft device embodying a valving mechanism that uses a 
surface-to-surface seal to prevent the inadvertant passage of fuel out of 
the valving mechanism. 
In accordance with the invention, a device is used to control the passage 
of fuel from a fuel tank to an engine. The device comprises a body 
including a chamber. An inlet member is connected to the body and has an 
inlet passageway for placing the fuel tank in fluid communication with the 
chamber. An outlet member is connected to the body and has an outlet 
passageway for placing the chamber in fluid communication with the 
motorcycle engine. An element is disposed within the body and movable 
between a position placing the inlet passageway in fluid communication 
with the chamber and a position preventing fluid communication between the 
inlet passageway and the chamber. A lock mechanism is used to secure the 
element in the position preventing fluid communication between the inlet 
passageway and chamber to prevent movement of the element to the position 
placing the inlet passageway in fluid communication with the chamber. 
Apparatus is disposed within the body for connecting the lock mechanism to 
the element to move the element when the lock mechanism moves and to 
prevent movement of the element until the lock mechanism moves.

Turning to FIG. 1, there is shown a motorcycle antitheft device 10 
constructed according to the present invention to control the passage of 
fuel from a motorcycle fuel tank (not shown) to a motorcycle engine (not 
shown). Device 10 comprises valving apparatus 12 to selectively permit and 
prevent the passage of fuel from the fuel tank to the engine and locking 
apparatus 14 to prevent movement of valving apparatus 12 when the fuel is 
prevented from passing to the engine and when a key 16 used with locking 
apparatus 14 is removed. 
An elongated cylindrically shaped body 18 is used with valving apparatus 12 
and includes a first end 20 and a second end 22. An axis 24 extends 
longitudinally between first end 20 and second end 22. Disposed 
symmetrically around axis 24 is a passageway 26, which extends into body 
18 from first end 20 toward second end 22. Passageway 26 has a first 
section 28 disposed adjacent first end 20, a second section 30 disposed 
adjacent first section 28 on the side away from first end 20, and a third 
section 32 forming a chamber disposed adjacent second section 30 on the 
side nearest second end 22. Second section 30 has a larger diameter than 
first section 28 to form a shoulder 100 facing toward second end 22. 
An inlet member 34 is connected to body 18 and disposed to extend radially 
away from body 18. Inlet member 34 includes a shoulder 36 with external 
threads 38 adapted to be threadedly connected to a port in the bottom of 
the motorcycle fuel tank. A first fuel inlet passageway 40 and a second 
fuel inlet passageway 42 are provided in inlet member 34 to place the fuel 
tank in fluid communication with third section 32 of passageway 26 
extending into body 18 from first and 20. If desired, a series of flats 44 
connected end to end may be provided around the periphery of outlet member 
34 to allow the use of a wrench to secure device 10 when mounting to the 
motorcycle fuel tank. 
An outlet member 46 is connected to body 18 and disposed to extend radially 
away from body 18 in a direction diametrically opposed from the direction 
of inlet member 34. Outlet member 46 is a tubular extension including a 
passageway 48 in fluid communication with a port 50 in body 18 leading to 
third section 32 of passageway 26. A lip 52 is provided on the free or 
outboard end 54 for securing a tube (not shown) in fluid communication 
with the motorcycle engine. 
A tubular member 56 is used to raise the intake port of first fuel inlet 
passageway 40 to a higher elevation than the intake port 58 of second fuel 
inlet passageway 42 when inlet member 34 is connected to the bottom of a 
motorcycle tank. Tubular member 56 is a pipe-like element having one end 
60 connected to outlet member 46 with the passageway 62 through the 
pipe-like element in fluid communication with first inlet passageway 40 
and the other end 64 forming intake port 66 for first inlet passageway 40 
disposed at an elevation above intake port 58 of second inlet passageway 
42 when inlet member 34 is connected to the bottom of the motorcycle fuel 
tank. 
To filter solid foreign matter from the fuel prior to passage of the fuel 
into first inlet passageway 40 and second inlet passageway 42, a screen 68 
may be used. Screen 68 has an elongated tubular shape with a first end 70 
being closed and a second end 72 being open. End 72 is attached to 
shoulder 36 of inlet member 34 to close the open end. 
Rotatably disposed within valve body 18 is a valve element 74, which 
selectively permits and prevents fluid communication between inlet 
passageways 40 or 42 and outlet passageway 48. Valve element 74 has the 
shape of a truncated cone with side walls 76 to prevent fluid 
communication between fuel inlet passageways 40 and 42 and outlet 
passageway 48 formed by a pocket 78 extending inwardly from truncated end 
80. A port 82 extends through side walls 76 to selectively place first 
fuel inlet passageway 40 in fluid communication with outlet passageway 48 
and second fuel inlet passageway 42 in fluid communication with outlet 
passageway 48. Tapered shoulders 84 engage tapered surfaces 86 in third 
section 32 of passageway 26 to provide a seal and prevent fluid from 
flowing between valve element 74 and body 18. A base shoulder 88 is formed 
by a pocket 90 extending inwardly from base 92 of valve element 74. 
Locking apparatus 14 is used to secure valve element 74 in the position 
preventing fluid communication between inlet passageways 40 and 42 and 
third section 32 of passageway 26 and to prevent movement of valve element 
74 to the position placing inlet passageways 40 and 42 in fluid 
communication with third section 32 of passageway 26. Locking apparatus 14 
includes a cylinder lock plug 94 disposed within first section 28 of 
passageway 26 for rotatable movement around axis 24. A number of lock pins 
96 are provided in lock plug 94 to move between a withdrawn position, as 
shown in FIG. 2, to allow rotating movement of plug 94 when key 16 is 
inserted into lock plug 94 and an extended position to engage a shoulder 
on body 18 and thereby prevent rotatable movement when key 16 is removed 
from lock plug 94. A latching member 98 is connected to plug 94 to extend 
into second section 30 of passageway 26 to connect lock plug 94 to body 18 
by abutting against shoulder 100 formed between first section 28 and 
second section 30 of passageway 26. A cover 102 is provided over lock plug 
94 to prevent access to plug 94. 
To move valve element 74 rotatably about axis 24 when lock plug 94 is 
rotated by movement of key 16 and to prevent movement of valve element 74 
until lock plug 94 is rotated by movement of key 16, move preventing 
apparatus 104 is provided. Apparatus 104 includes a spindle rod with one 
end 106 attached to lock plug 94 and another end 108 attached to valve 
element 74. 
Valve element 74 is urged by apparatus 110 toward second end 22 of body 18 
and into engagement with third section 32 of passageway 26 such that 
tapered shoulders 84 are in secure engagement with tapered surfaces 86 and 
thereby provide an enhanced surface-to-surface seal. Urging apparatus 110 
is a coil spring disposed around spindle 106 which extends between end 112 
of lock plug 94 and base shoulder 88 of valve element 74. 
In operation, device 10 is connected to a motorcycle tank in place of the 
normal fuel valve by screwing threads 38 into the matching internal 
threads provided around the opening through the bottom of a motorcycle 
fuel tank. Device 10 is tightened by using a wrench to grip flats 44 and 
rotate device 10 relative to the motorcycle. Since the opening leading 
into the motorcycle fuel tank is in the bottom of such tank, intake port 
66 will be at a higher elevation than intake port 58, as generally 
represented in FIG. 3. A tube running to the carburetor of the motorcycle 
engine is then slipped over tubular outlet member 46 and secured thereto 
by use of a conventional clamping device which is disposed around 
passageway 48 between body 18 and lip 52 thereby placing the chamber 
formed by third section 32 and valve element 74 in fluid communication 
with the motorcycle engine. Key 16 is then inserted into lock plug 94 
allowing pins 96 to move to the disengaged position with body 18 and 
rotated clockwise around axis 24 to a position represented by the word ON, 
hidden by key 16 in FIG. 1, wherein port 82 is aligned with first fuel 
inlet passageway 40 to place this inlet passageway in fluid communication 
with the chamber in body 18. When the fuel level in the motorcycle fuel 
tank drops below intake port 66 during normal driving operations, key 16 
is rotated counterclockwise around axis 24 to a position represented by 
the letter R, as seen in FIG. 1, wherein port 82 is aligned with second 
fuel inlet passageway 42 to place this inlet passageway in fluid 
communication with the chamber in body 18. When the motorcycle is no 
longer being used by the owner, key 16 is moved, either from the ON or R 
position, to a position represented by the word OFF, as seen in FIG. 1, 
wherein port 82 is positioned between first fuel inlet passageway 40 and 
second fuel inlet passageway 42 such that side walls 76 of valve element 
74 prevent fluid communication with the chamber in body 18. Key 16 is 
removed from lock plug 94 and pins 96 move into engagement with body 18 
which prevents valve element 74 from moving and thereby prevents fuel from 
passing from the motorcycle fuel tank to the motorcycle engine.