Linkage lock device

A linkage lock device is provided for fastening objects having either regular or irregular shapes. The lock is composed of a plurality of identical arcuate bars having opposing ends of each bar pivotally connected to an end of another one of the bars to form a chain. One of a pair of free ends is formed to receive a lock mechanism which releasably secures the other free end to form a closed loop to encompass the object being secured against theft. Each pivotal coupling is formed by a pin secured through hardened washers into which the ends of the pin are received.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a locking device having a plurality of links, and 
more particularly to a locking device for securing objects of regular or 
irregular shape. 
2. Prior Art 
Many types of locks have been invented for various purposes. One such type 
is a U-shaped lock, as shown in FIG. 15, which includes a shackle having 
its respective ends insertable into a pair of corresponding apertures in a 
tubular member and locked by a lock mechanism. This lock has a rigid 
structure which can only be secured about an object which has an identical 
shape or which is smaller in size than the opening defined by the shackle. 
If the object to be secured has a larger size or has an irregular shape, 
the U-shaped lock is then useless. 
A further prior art lock is a Bar Lock Linkage, U.S. Pat. No. 3,747,376, as 
shown in FIG. 16. Such consists of a bar lock having a plurality of bar 
links which are pivotally fastened together end to end by rivets. The bar 
lock has two free ends fastened together by a barrel lock. Each bar link 
is able to pivot relative to one another at the pivoted connections 
enabling the bar lock to be folded together into a compact package for 
storage purposes. But at least one acute angle is formed by a pair of the 
bar links when locking an object, and the acute angle may incidentally 
hurt someone. 
Another prior art lock is a Bike Security Device, U.S. Pat. No. 3,784,876, 
as shown in FIG. 17. That device consists of three links, the first link 
extending a distance which is normally longer than the span between the 
wheels of a bicycle and having a pair of loops at respective ends adapted 
for articulated engagement with a second and a third link in a pivotal 
manner. This device utilizes a padlock to form a securing loop. The 
padlock is separate from the links and that requires them to be stored 
separately. 
A fourth example of a prior art lock is a Ski Lock, U.S. Pat. No. 585,184, 
as shown in FIG. 18. The Ski Lock comprises a plurality of plates hinged 
together to form into a rectangular structure so as to surround a pair of 
skis disposed in bottom-to-bottom relationship. The end plates are locked 
together by a padlock with a chain surrounding a permanent fixture so that 
the skis cannot be stolen. The padlock is also separate from the plates 
and is required to be stored separately. 
A fifth example of a prior art lock is a Wheel Lock, U.S. Pat. No. 
4,760,718, as shown in FIG. 19. This type of lock comprises a plurality of 
rigid members being pivotally coupled to each other and having a lockable 
connection at the outer ends, so as to form a loop to lock a wheel to an 
associated fixed element. This device is limited by its space to secure 
objects. Furthermore, the linkage of such prior art locks is generally 
composed of a bolt A, as shown in FIG. 20, having a head A1 on top and a 
shank A2 which includes a larger section A21 and a smaller section A22. A 
pair of apertures C1, D1 are formed on lock rod C, and D respectively. The 
inner diameters of the apertures C1, and D1 are slightly larger than the 
larger section A21 so that the larger section A21 can insert through the 
apertures C1 and D1. The smaller section A22 will be exposed outward from 
the end opposite the head A1 and will be hammered flat to hold the bolt A 
in place, as shown in FIG. 21. Because of the hammering requirement, the 
bolt A is unable to be processed with heat treatment. This causes the bolt 
A to be easily broken by shear forces, as shown in FIG. 22. 
SUMMARY OF THE INVENTION 
It is the primary object of the present invention to provide a linkage lock 
device having linkages which are processed with heat treatment that will 
prevent the linkages from being easily broken by severe forces applied 
thereto. 
It is another object of the present invention to provide a linkage lock 
device which does not form an outwardly directed acute angle. 
It is a further object of the present invention to provide a linkage lock 
device which requires less storage space. 
It is still a further object of the present invention to provide a linkage 
lock device which is easy to operate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings wherein such are provided for the purpose of 
illustrating preferred embodiments only, and not for the purpose of 
limiting an inventive concept. The linkage lock device, according to the 
present invention, comprises a plurality of arcuate bars 1 which are 
hingedly fastened together end to end by pins 2 and a pair of upper and 
lower washers 3 and 4 to form a chain. The washers 3 and 4 are processed 
with heat treatment to increase their hardness. 
The respective ends of each bar 1 are forged to form flat surfaces 13, and 
have apertures 14 formed at a center portion of the flat surfaces 13. One 
free end of the chain is inserted into a groove 51 of a lock mechanism 5 
and secured by a bolt 6 inserted from a vertical hole 52 formed in the 
bottom of the lock mechanism 5. The bolt 6 has a slot 61 at a top portion 
thereof. The vertical hole 52 intersects with the groove 51 and 
interconnects with a latch hole 55 and a lock core hole 53. Therefore, the 
bolt 6 is tightened with a standard screw driver from the lock core hole 
53, engaging the slot 61 to fasten the bolt 6. The latch hole 55 is 
adapted to receive the other end, the free end, of the chain. This free 
end functions like a latch having a recessed portion which has a 
protuberance 121 extending upwardly, as shown in FIG. 3A, adapted to be 
inserted into the latch hole 55 and a recessed portion 541 of a lock core 
54 for securement thereof, as shown in FIGS. 3B and 3C. 
Each of the pins 2 includes a head 21 at the top, a first section 22, and a 
second section 23. Each of the washers 3 and 4 includes a respective 
through aperture 31, 41 concentrically formed therein. The aperture 31 
includes a first section 311 having larger inner diameter adapted to 
receive the head 21 of the pin 2, and a second section 312 having smaller 
inner diameter 312 adapted to receive the first section 22 of the pin 2. 
The aperture 41 includes a first section 411 adapted to receive a 
flattened portion of the second section 23 of the pin 2, and a second 
section 412, as shown in FIG. 4A. The pin 2 is inserted into the upper 
washer 3 and through the apertures 14 and the lower washer 4. The second 
section 23 of the pin 2 will extend outwardly from the first section 411 
of the lower washer 4. The exposed portion of the second section 23 of the 
pin 2 is then flattened and remains within the first section 411 of the 
lower washer 4, as shown in FIG. 4B. 
To lock the present invention, the rod 12 is pushed toward the bar 11 and 
the free end is inserted into the aperture 55 of the lock mechanism 5 
until the lock core 54 confines the movement of the protuberance 121, as 
shown in FIG. 5. 
In order to secure an object in a limited space, the linkage is flexible by 
pushing the articulated areas, as shown in FIG. 6. The linkage may even be 
folded completely, as shown in FIG. 7. The present invention may be varied 
in size by adding or deducting the linkage bars 1. For instance, if the 
object to be secured has a larger size, more bars 1 may be employed. On 
the other hand, if the object to be secured is of a smaller size, less 
bars 1 may be employed, as shown in FIG. 8. 
Another embodiment of the pin 2 may be employed, as shown in FIG. 9. The 
pin may have an enlarged section 22 at a middle section of the pin 2, and 
a pair of sections 23 of reduced diameter at respective opposing ends 
thereof. The reduced sections 23 will be exposed outwardly from the first 
sections 311 and 411 of the washers and will be flattened and remain 
within the sections 311 and 411. 
An alternate embodiment of the washers 3 and 4 may be employed, as shown in 
FIG. 10. The washers 3 and 4 have through aperture 32, 42 respectively. 
Another embodiment of the pin 2 is shown in FIG. 11, the pin having a 
cylindrical body of constant diameter with the respective ends extending 
outwardly from the washer apertures 31 and 41. The exposed portions of the 
pin 2 are to be flattened and remain within the first sections 311 and 411 
of the washers 3 and 4, as shown in FIG. 12. 
A second embodiment of the lock mechanism 5 is employed, as shown in FIG. 
13, which utilizes a rivet 58 to replace the bolt 6. The rivet 58 is 
inserted into the lock body from the aperture 56 located at the bottom and 
extends outwardly from the top portion of the aperture 56. The aperture 56 
comprises a larger inner diameter 57 at the top portion thereof, which is 
adapted to receive a flattened portion of the rivet 58 therein. 
A third embodiment of the lock mechanism 5 is shown in FIG. 14 which 
includes a post 59 integrally formed at the bottom portion of the lock 
body and extending downwardly therefrom for insertion through the aperture 
111 of the bar 11 and the aperture 501 of a head 50. The exposed portion 
of the post 59 will be flattened and embedded within the aperture 501. 
While there has been described and illustrated several embodiments of the 
present invention, it will be clear that variations in the details of the 
embodiments specifically illustrated and described may be made without 
departing from the true spirit and scope of the invention.