Motorcycle lock

A lock for a motorcycle has a generally U-shaped construction. The open end of the U is slipped over the brake rotor of the front wheel or the sprocket of the rear wheel of the motorcycle. A bolt then extends across the open end of the U-12 shape to hold the device in place. This bolt is engaged by a spring loaded pin so as to hold it in position. Rotation of the wheels is then prevented by contact between the lock and the brake calipers on the front wheel or the chain or sprocket on the rear wheel. In order to release the bolt, a cam and a spring biasing the pin in the opposite direction are provided so that rotation of the cam allows the pin to be withdrawn from the bolt. The lock includes a lock-out mechanism which prevents the motorcycle from being started when the lock is in place because the lock-out mechanism retains the ignition key. In addition to the lock, a single loop cable can be provided for attachment about a stationary object and received within a channel in the lock. This channel in the lock also has a spring loaded pin which engages the head of the cable under the influence of the cam.

BACKGROUND OF THE INVENTION 
This invention relates to vehicle locks and, more particularly, to 
motorcycle locks. 
In recent years, the cost of motorcycles has escalated substantially. In 
many instances, a motorcycle can cost as much as an automobile. Therefore 
it is important to provide means for reducing the potential theft of such 
a vehicle 
With automobiles the starting and steering mechanisms are within the 
interior of the vehicle so that some security can be provided by locks on 
the doors of the vehicle. However, with a motorcycle, the starter and 
steering wheel, and indeed the entire engine, is exposed so that it can be 
tampered with by potential thieves. 
The most typical way of protecting a motorcycle against theft is by means 
of a large chain, which can be looped through one of the wheels and/or a 
portion of the frame and then extended about a stationary object, such as 
a tree or lamp post. In order to provide this capability the chain has to 
be relatively long, in the neighborhood of 4 to 6 feet. Thus, it is very 
cumbersome to store. In addition, the links of the chain are readily 
exposed so that a thief with the proper equipment can cut through the 
links of the chain at a critical point and remove it from the motorcycle. 
Another type of motorcycle lock which is sold under the trade name 
KRYPTONITE is in the form of a large U-shaped piece 
Another type of motorcycle lock which is sold under the trade name 
KRYPTONITE is in the form of a large U-shaped piece which has a straight 
cylinder extending across the open end of the U-shape. Typical Kryptonite 
locks are about a foot and a half in length and are thus also very 
difficult to store. The U-shaped portion of the lock also extends through 
a wheel of the vehicle or motorcycle. It essentially prevents theft 
because the lock prevents complete rotation of the wheel in that it comes 
against the portion of the fork holding the wheel onto the motorcycle. 
However, kryptonite-type locks can also be removed with metal cutting 
tools. 
It would be advantageous to have a motorcycle lock which is relatively 
small in size, for example so that it can be carried in a person's coat 
pocket, and that is difficult to remove even with metal cutting tools. 
SUMMARY OF THE INVENTION 
The present invention is directed to a motorcycle lock which is relatively 
small in size and is difficult to tamper with. This lock is created by 
means of a device which fastens onto the brake rotor of the motorcycle and 
has a sufficient thickness so that it cannot pass between the calipers of 
the motorcycle brake on that wheel or the wheel fork. 
In an illustrative embodiment of the invention, the lock is in the form of 
a generally U-shaped device of approximately 6 inches in length and 21/2 
inches in width. The gap between the legs of the U-shape is only wide 
enough to allow it to slide over the motorcycle brake rotor, i.e. 
approximately one-half inch. 
When the lock is slipped over the brake rotor, it extends from the outer 
edge of the rotor to one of the plurality of apertures at its inner edge. 
A locking bolt then extends across and closes the end of the gap between 
the legs of the U-shape. This bolt is held in the locking position by 
means of a spring loaded locking pin that is received in a recess at the 
end of the bolt. The locking pin is in the form of two sections which are 
biased apart by means of an inner spring. In addition, the overall pin is 
spring biased out of the recess in the bolt by means of an outer spring. A 
rotatable cam fastened to the end of a lock cylinder has a cam face which 
can be turned by the key for the lock cylinder so as to compress the outer 
spring on the locking pin and keep it engaged in the recess of the bolt. 
In a preferred embodiment of the invention, a rotatable lock-out device is 
included in a lock-out channel in one leg of the U-shaped device. In one 
position, a cam surface on the lock-out device causes an additional pin to 
extend into a further recess in the locking bolt channel against the bias 
of a lock-out spring. Thus, with the lock-out device in this position the 
locking bolt cannot be engaged to close the gap between legs of the 
U-shaped device and fasten the lock to the brake rotor. However, the 
lock-out device can be rotated to a second position by the ignition key of 
the motorcycle, as opposed to the lock key. This moves the cam surface so 
the lock-out spring can bias the lock-out pin from the bolt channel so the 
locking bolt can slide across the gap and fasten the lock to the brake 
rotor. 
Once in the second position the lock-out device can be removed from the 
lock-out channel. However, the lock-out device clamps onto the motorcycle 
ignition key when the lock-out device is not installed in the lock. 
Therefore, when the user approaches the motorcycle to drive off, the 
lock-out device is clamped on the ignition key and prevents the user from 
starting the motorcycle. This is an added safety feature since it can be 
extremely dangerous to start and drive off on the motorcycle with the lock 
engaged. 
To start the motorcycle the user must first remove the lock from the rotor, 
then insert the combined lock-out device and ignition key into the 
lock-out channel of the locking device. When the key is rotated, the 
lock-out pin is forced into the locking bolt channel by the movement of 
the cam surface on the lock-out device. If a spring is provided at the end 
of the locking bolt, the locking bolt will automatically retract, opening 
the gap between the legs of the locking device. 
In a still further embodiment of the invention, a single looped cable can 
be provided and attached to the locking device. The loop can be placed 
around some stationary item and an end of it inserted into the same 
channel as the lock-out device, once the lock-out device is removed. This 
cable end has a recess which is engaged by a cable pin that has a double 
acting spring. When the cable end is pushed into the channel for the 
lock-out device, the cable pin engages a recess in the end, thus holding 
it in place. When the lock key and the cam attached to it are rotated, not 
only does it release the locking pin bolts, is also releases the cable pin 
so the cable can be removed. 
According to another provision of the present invention, a shield plate 
extends from the gap between the legs of the lock and surrounds some of 
the bolts on the hub. This makes it more difficult to release the front 
wheel during a theft attempt.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
In FIG. 1 there is shown a motorcycle 10 which is secured to a stationary 
object, for example a lamp post 12, by means of a lock 14 and single loop 
cable 16 of the present invention. As can be seen in FIG. 1, and in more 
detail in FIG. 2, the brake rotor 20, which is provided on the front wheel 
of the motorcycle, is relatively thin and fits between the calipers 22 of 
the brake. When the brakes are applied, the calipers engage the rotor 20 
to slow down and stop the motorcycle. 
As can be seen from FIGS. 1 and 2, the lock 14 is clamped onto the rotor. 
It has a width, or thickness, such that it is impossible for the lock to 
pass beyond the calipers 22 or the fork 23 which holds the wheel on the 
frame. Therefore, the motorcycle front wheel can only turn a short 
distance in either direction before it is abruptly halted. 
It can be seen that most of the motorcycle can be stolen if the front wheel 
is removed. In order to reduce the possibility of this, a shield 24 can be 
included in the lock 14. This shield as shown in FIG. 2 covers some of the 
bolts on the hub of the motorcycle, thus making it difficult to remove the 
front wheel. It should be noted that shield 24 as shown in FIG. 2 covers 
the bolts near the hub as well as the axle bolt of the hub. That is, the 
shield is outside the end of the fork 23, thus making it difficult to 
remove the front wheel. 
In an alternative embodiment (FIG. 10), the shield 24 extends beneath the 
fork 23, but still covers some of the bolts on the wheel, making it 
difficult to remove the front wheel. 
The distance from the hub 26 to a portion of the brake rotor will vary for 
different motorcycles. As a result, the shield is provided with a series 
of openings 25 so that the user can select the opening which fits with the 
locking bolt of the lock and still provides the maximum amount of coverage 
of the hub bolts. 
FIG. 3A provides a cross-sectional vie of the lock along line 3--3 of FIG. 
2. The lock 14 basically has an inverted U-shape, with leg portions 30, 32 
connected by a base portion 31. Leg 32 is made shorter than leg 30 so that 
it avoids the hub 26. The separation between legs 30 and 32 is 
sufficiently wide to fit over the brake rotor 20 and shield 24. Also, the 
overall width of the lock 14 is wide enough to prevent it from fitting 
between the calipers 22 of the brake or the fork 23, thus preventing 
complete rotation of the front wheel of the motorcycle. 
A locking bolt 33 is slidably positioned in a locking bolt channel 34 which 
extends through leg 30, and at least partially through leg 32, near the 
open end of the U-shaped lock 14. This locking bolt is positioned such 
that it can extend through one of the apertures near the interior edge of 
the brake rotor, whereby the lock 14 is retained on the rotor. The forward 
end of locking bolt 33 preferably has a tapered end 40. When the locking 
bolt 33 slides across the gap between legs 30 and 32, this tapered end 40 
comes into engagement with a locking bolt pin 35. This locking pin has two 
cylindrical sections connected by a dual action springs. The lower section 
52 is connected to the upper section 54 by means of an inner spring 53. 
This inner spring 53 tends to bias the sections 52, 54 away from each 
other. An exploded view of the locking bolt pin 35 is shown in FIG. 8. 
Locking bolt pin 35 is contained in a locking bolt pin channel 36 which has 
a ledge 37 where it narrows towards its lower portion. The locking bolt 
pin 35 also has a ledge 55 towards its upper end where the upper part 54 
is larger or wider. An outer spring 56 of the dual action locking bolt pin 
35 extends between the ledge 37 of the channel and the ledge 55 on the 
upper part 54 of locking bolt pin 35. As a result, this outer spring tends 
to bias locking bolt pin 35 away from the bolt channel 34 in which locking 
bolt 33 slides. 
At the upper end of locking bolt pin 35, there is a lock cylinder channel 
38 which holds a lock cylinder 39 which has a lock cylinder cam 39' 
attached to its end. At the outer edge of cam 39', there is a cam surface 
62 which engages the end of locking bolt pin 35. During the locking 
operation, when a lock key (not shown) operates lock cylinder 39, cam 39' 
is rotated so that its surface 62 pushes locking bolt pin 35 downwardly 
against the action of outer spring 56. As the tapered end 40 of locking 
bolt 33 comes into contact with the end of part 52 of locking bolt pin 35, 
inner spring 53 is compressed and part 52 rides up over the end of the 
locking bolt 33. Locking bolt 33 includes an annular recess 42. Thus, when 
the locking bolt 33 extends sufficiently into leg 32, part 52 snaps into 
recess 42 under the influence of inner spring 53. As long as cam surface 
62 holds the locking bolt pin 35 in a downward position against the force 
of outer spring 56, inner spring 53 will cause part 52 to be retained in 
the recess 42. 
When it is desired to release locking bolt 33 so that the lock 1A can be 
removed from the brake rotor, cam 39' is rotated by operation of the 
cylinder lock 39 using the lock key so that surface 62 allows spring 56 to 
cause the locking bolt pin 35 to retract from recess 42 in bolt 33. Then 
locking bolt 33 can be withdrawn axially (to the left in FIG. 3) so the 
open end of the lock 14 is clear so it can be removed from the brake rotor 
20. Movement of locking bolt 33 can be by the manual application of 
pressure on the end of locking bolt 33 near surface 40, when the locking 
bolt 33 extends through leg 32, so as to cause the left end of locking 
bolt 33 to project from leg 30. If locking bolt 33 does not extend through 
leg 32, (as illustrated) a spring 41 at the end of channel 34 pushes 
locking bolt 33 partially out of channel 34 so it can be grasped and 
pulled the rest of the way out. 
If desired, a single loop cable 16 can be fastened to the lock 14. FIG. 5 
shows the end 15 of this cable. Like the locking bolt 33, this end has 
tapered surfaces 17 and an annular recess 18. This end 15 is inserted into 
a lock-out channel 63 in leg 30 of the lock 14. A further channel 65 which 
contains a cable locking pin 70, intersects channel 63. Cable locking pin 
70 is substantially the same shape as locking bolt pin 35. In particular, 
it has a lower narrow portion 72 connected to an upper portion 74 that has 
a ledge 75 where the upper portion becomes wider. These two parts 72, 74 
are connected by two springs, i.e. an inner spring 73 that biases the 
parts away from each other and an outer spring 76 that extends from a 
ledge 67 where channel 65 narrows to the ledge 75 on cable locking pin 70. 
As a result of outer spring 76, the pin 70 is biased away from channel 63. 
However, there is a surface 64 on cam 39' which causes cable locking pin 
70 to slide axially downward against the force of spring 76, so that the 
lower portion 72 extends into channel 63. 
If the head 15 of cable 16 is inserted into channel 63, the tapered end 17 
pushes against part 72 causing it to ride up over the edge of the head and 
compress spring 73. However, when it is fully inserted, part 72 projects 
downwardly into the annular channel 18 of head 15 under the influence of 
inner spring 73 and locks the head 15 into the body of lock 14. 
If cam 39' is rotated by the lock key operating the lock cylinder 39, it 
not only releases locking bolt pin 35 from locking bolt 33, it also 
releases cable locking pin 70 from the end of cable 16 (FIG. 3B). 
As shown in FIGS. 2 and 3A, a shield 24 may be inserted into the gap 
between legs 30, 32 of the lock 14. This shield has multiple apertures 25, 
only one of which is retained on locking bolt 33 in the locking position. 
By selecting the particular aperture, the extension of the shield from the 
lock 14 towards the hub 26 can be adjusted for different size wheels and 
rotors. 
The shield 24 extends down to the hub and covers two or more of the bolts 
which fastened the wheel and/or rotor to the hub. As a result of this 
shield, it is difficult to remove the front wheel and to defeat the 
locking mechanism of the present invention. 
With the lock of the present invention, it could be very dangerous to the 
rider and damaging to the vehicle, if the user were to accidentally start 
the motorcycle and try to drive off. In the event this occurred, the 
motorcycle would move properly for a few feet until the lock 14 came into 
engagement with the brake calipers 22 or fork 23. At that point, rotation 
of the front wheel would be immediately stopped. Such a sudden stop of the 
vehicle could throw the rider over the handle bars, thus injuring the 
rider. Also, it is possible that engagement between the lock and the brake 
calipers could damage the brake calipers and/or the rotor. In order to 
prevent this from happening, a lock-out device 82 is included in the 
present invention. 
The lock-out device 82 is intended to be inserted into the lock-out channel 
63 as shown in FIG. 3C, and it has the shape shown in FIGS. 6 and 7. 
Before the lock 14 is put into use, the lock-out device 82 is retained in 
channel 63. In this position, the lock-out device presses on a pin 90 and 
causes it to extend into the lock-out channel 63 and block the end of the 
locking bolt 33 (FIG. 3). In this position, the locking bolt 33 cannot be 
slid across the open end of the lock and therefore the lock cannot be 
engaged. This is true because the lock-out device 82 has a cam 84 that 
presses on the end of pin 90. As the lock-out device 82 is rotated, the 
cam ceases to press on pin 90 and a spring 92 on pin 90 causes pin 90 to 
move away from channel 34 so that the pin 90 no longer blocks operation of 
locking bolt 33. 
Lock-out device 82 is adapted to be rotated by the ignition key, not the 
lock key. As shown in FIG. 9, the vehicle ignition key 100 is provided 
with a series of indentations 102 along its edges. Starting with the 
lock-out device 82 in the lock 14, when the key is inserted into key slot 
85 and rotated, these ridges engage ratchet teeth 86' located on pivotal 
levers 86. As a result, these levers 86 are caused to rotate and compress 
springs 88. If an attempt is made to withdraw the key, the force of 
springs 88 acting on levers 86 prevents this from occurring. Therefore, 
when the lock-out device 82 is rotated to the proper position, so that cam 
84 lines up with a slot 65 in channel 63, as best shown in FIG. 4, the 
lock-out device 86, with the ignition key 100 locked into it, can be 
withdrawn from channel 63. This allows pin 90 to withdraw from engagement 
with locking bolt 33. 
On the side of the lock-out device 82, opposite from cam 84, there is a 
guide pin 87 (FIG. 7). In channel 63 there is another annular recess 65,, 
which receives the pin 87 to assist the cam 84 in guiding rotation of the 
lock out device. 
At this stage, i.e. when the lock out device 82 has been removed, the lock 
14 can be installed on the brake rotor 20 as described above and the cable 
head 15 can be locked into lock-out channel 63. However, the ignition key 
100 for the motorcycle is now retained in the lock-out device 82. 
Therefore, when the user approaches the bike to drive away and attempts to 
insert the key into the motorcycle ignition, the lock-out device 82 will 
prevent proper operation. 
As an alternative, a further channel 104, shown in dotted-line in FIG. 3A, 
can extend from lock-out channel 63 to the lock cylinder channel 38 which 
holds cam 39'. In this channel 104 there is a pin 110, which is biased 
into an annular recess 108 in lock cylinder 39 or cam 39' via the cam 
surface 84 on lock-out device 82. As a result, cam 39, cannot be rotated 
so as to release pins 70 and 35 until the lock-out device 82 is removed 
using the ignition key 100. When it is removed, a spring 112 between a 
lower enlarged part 111 of pin 110 and a ledge 105 in the channel 104, 
biases pin 110 away from the recess 108 in lock cylinder 39 or cam 39'. 
When the lock-out device 82 (with the ignition key 100 gripped therein) is 
returned to the lock-out channel 63, shafts 89 of the lock-out device, 
which project from its end (FIG. 6), come into contact with a shelf 66 in 
channel 63 (FIG. 3). These shafts 89 move axially into the lock-out device 
82 and cause rotation of levers 86. Because the levers are eccentrically 
mounted, movement of these levers against the action of springs 86 causes 
them to move away from the key channel 85. As a result the ratchet teeth 
86, no longer engage the grooves 102 in the ignition key 100 and the 
ignition key can be removed. 
It is difficult to take off the front wheel because of the brake calipers. 
However, as a further alternative, the gap between legs 30 and 32 can be 
made even wider so that it fits over the rear wheel, sprocket and chain. 
As a result, the rear wheel will not be able to turn because the rear 
sprocket will not be able to turn. In order to defeat the device in this 
position you have to cut the chain. However, if the chain is cut, you have 
to disassemble the engine in order to insert a new one. 
With a still further alternative, the cable 16 can be made long enough so 
that it can reach the front wheel from the back wheel and vice versa. 
While the invention has been particularly shown and described with 
reference to preferred embodiments thereof. It will be understood by those 
skilled in the art that various changes in form and detail may be made 
therein without departing from the spirit and scope of the invention.