Bicycle locking mechanism

A bicycle locking mechanism is provided including a tubular member which may form part of a bicycle frame, such as the tubular seat post, for example, and an elongated, collapsible, securing element for securing the bicycle frame to an object such as a post or bicycle rack. The elongated, collapsible, securing element has first and second ends and is collapsed in size to a length which is no greater than the length of the tubular member. The securing element fits substantially within the tubular member, when not in use, and is of sufficient length when withdrawn from the tubular member to wrap around an object for securing the bicycle frame thereto. A hinge pin assembly is provided for attaching the first end of the securing element to the tubular member. The securing element may be an elongated, interconnected, linkage assembly or it may consist of a flexible cable.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates generally to bicycle locking mechanisms and more 
specifically to a bicycle lock which is integral to the bicycle frame. 
2. Description of the Prior Art 
Various bicycle locks, chains, cables, and solid bar type have been 
previously used to secure bicycles to fixed objects such as fence posts, 
bike racks, and the like. Although they all to some degree provide 
security, the issue of portability is often ignored as a trade off. To 
overcome the portability issue, prior inventions have taken the 
aforementioned existing locking mechanisms and designed a holder or 
bracket accessory to accommodate the need to conveniently carry the lock 
apparatus on the bicycle. The result is either additional hardware bulk 
and weight on the bicycle, or an unorganized method of wrapping cables, 
chains, and locks around the saddle post. 
Additionally, with the increasing portability, adjustability, and component 
interchange of modern bicycles, quick release type mechanisms have 
penetrated the bicycle component market. Wheels and seat posts are often 
removable in a few seconds to accommodate portability and adjustability. 
This highly desired feature, however, has the inherent drawback of making 
the individual components less "theft proof". As a consequence, either 
more locks are needed to secure the individual components, or longer more 
complicated cabling schemes are implemented to thread through as many of 
the easily removable components as possible. In turn, added weight and 
bulk become part of the locking mechanism. 
In particular, the need to secure the bicycle seat or saddle has become 
more necessary as new saddle designs progress. Saddles can now be of 
significant cost, and have been very difficult to adequately secure. Due 
to the de facto mechanical standards used for interchange of saddles and 
posts, there is very little space mechanically to incorporate security 
into the saddle itself. 
Accordingly, it is a primary object of the invention to provide a bicycle 
locking mechanism which offers both security and inherent portability. 
Another object of the invention is to provide a bicycle locking mechanism 
which attaches integrally to the bicycle seat post and saddle itself while 
in the locked state. 
Still another object of the invention is to provide a bicycle locking 
mechanism which does not distract visually from the intended aesthetic 
look of the bicycle. 
Yet another object of the invention is to provide a bicycle locking 
mechanism which adds little or no mechanical bulk to the bicycle that can 
otherwise interfere with cycling and/or induce unwanted rattling while 
cycling. 
SUMMARY OF THE INVENTION 
This invention is directed to a unique bicycle locking mechanism which is 
portable and completely self contained within the confines of the bicycle 
frame itself. Broadly, the bicycle locking mechanism of the invention 
comprises a tubular member which forms part of the bicycle frame, such as 
the tubular seat post, for example, and an elongated, collapsible, 
securing element for securing the bicycle frame to an object such as a 
post or bicycle rack. The elongated, collapsible, securing element has 
first and second ends and is collapsed in size to a length which is no 
greater than the length of the tubular member. The securing element fits 
within the tubular member when not in use, and is of sufficient length 
when withdrawn from the tubular member to wrap around an object for 
securing the bicycle frame thereto. Means are provided for attaching the 
first end of the securing element to the tubular member and for fastening 
the second end of the securing element to the bicycle frame after wrapping 
around the object. The securing element may be an elongated, 
interconnected, linkage assembly or it may consist of a flexible cable. In 
either case, the securing element is preferably attached to a hinge pin 
assembly mounted inside the tubular member and including means for 
limiting its movement therethrough. Of course, other types of elongated, 
collapsible, securing elements may be employed in the practice of the 
invention. 
In particular, the hollow tube of the seat post, and optionally, the handle 
bar tubing, is made available to house the bicycle locking mechanism of 
the invention while the locking mechanism is not in use and security of 
the bicycle is not necessary. Accordingly, the locking mechanism of the 
invention presents no visual distraction to the bicycle itself and 
preserves the aesthetic purity of the bicycle which is so important to 
many cycling enthusiasts. 
By incorporating the locking mechanism into the existing seat post 
assembly, for example, the need to provide additional cable, chain, or 
locks to secure this assembly is eliminated. This in turn offers the 
advantage of reduced complexity and weight of total components typically 
functioning for security purposes only. 
Inherently, the locking mechanism offers extreme portability in that it is 
entirely self contained within the existing structure of the bicycle 
frame. Therefore, there is no chance of the locking mechanism interfering 
with the rider as is often the case in the mounting and storing of locks 
typically in the prior art. 
Additionally, proper design can be employed to eliminate the tendency for 
the subcomponents of the locking mechanism to rattle while in transit. 
Consequently, the elimination of extraneous rattle noises allows the 
cyclist to more accurately assess the mechanical state of his bicycle 
while riding it which may often be deemed critical to the rider.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawing and more particularly to FIG. 1, there is 
shown a bicycle locking mechanism embodying the invention. As shown, the 
locking mechanism is preferably trapezoidal in shape and includes as one 
leg thereof a tubular post 10 having an outside diameter appropriate for a 
slip fit into a tubular bicycle frame. A typical bicycle frame is shown, 
for example, in FIG. 5. The inside diameter of the tubular post 10 is 
preferably made as large as possible while at the same time maintaining 
the necessary structural integrity typically required by a bicycle seat 
post. 
An elongated, collapsible, securing element denoted by the reference letter 
"L" is provided and forms the other legs of the trapezoidal locking 
mechanism according to the invention. The collapsible, securing element in 
this embodiment comprises a linkage assembly including two half length 
linkages 12a and 12b and a full length linkage 13. 
A retractable hinge stop 11 is inserted into the lower end of tubular post 
10. The hinge stop 11 is of cylindrical shape and has an outside diameter 
no greater than required for a slip fit into the tubular post 10. The 
hinge stop 11 provides a hinge point around a hinge pin 14 for rotatably 
joining thereto the half length linkage member 12a and concurrently 
provides a mating mechanism to the tubular post 10. The hinge pin 14 is 
positionally fixed to retractable hinge stop 11, through two ears 11a and 
11b extending axially from the cylindrical portion of the retractable 
hinge stop 11. 
The half length linkage 12a is sandwiched at one end between the ears 11a, 
11b and forms the first segment or link in the collapsible securing 
element L. The half length linkage 12a is an oblong member of rigid 
material having an elongated slot 12c formed in the central portion 
thereof. The length of the linkage 12a is no greater than half the length 
of tubular post 10 and its width is no greater than the inside diameter of 
tubular post 10. The depth of the linkage 12a is no greater than the 
distance between the two ears 11a, 11b of retractable hinge stop 11. 
The linkage 12a is positioned so that hinge pin 14 resides within the slot 
12c, the width of which is no less than the diameter of hinge pin 14. The 
slot 12c extends lengthwise to within approximately the diameter of the 
hinge pin 14 at each end of the linkage 12a. Optionally, each end of half 
length linkage 12a may be suitably rounded to accommodate pivoting and 
rotation of adjacent components so as to minimized interference. 
The second segment or link in the collapsible securing element L is the 
full length linkage 13. The full length linkage 13 is an oblong member of 
rigid material having an elongated slot 12c also formed in the central 
portion thereof. The linkage 13 has a length which is no greater than the 
length of tubular post 10 and a width which is no greater than the inside 
diameter of tubular post 10. The depth of the linkage 13 is again no 
greater than the distance between the ears 11a, 11b of the retractable 
hinge stop 11. The linkage 13 is similar in structure to half length 
linkage 12a, except that its length is approximately double that of the 
half length linkage members. 
The full length linkage 13 is linked to half length linkage 12a in a manner 
similar to a typical chain. Each of the links, i.e., half length linkage 
12a and full length linkage 13, is interlocked within the closed loop 
structure of the adjoining linkage, and approximately perpendicular 
axially to the corresponding adjoining linkage. 
The third segment or link in the collapsible, securing element L is the 
half length linkage 12b. The half length linkage 12b is identical in shape 
and form to half length linkage 12a. This linkage 12b is similarly linked 
to full length linkage 13 in the same manner as half length linkage 12a at 
the opposite end of full length linkage 13. The locking mechanism is 
closed via a locking device designed to pin half length linkage 12b to 
saddle mount base 15 as shown in FIG. 4. 
The saddle mount base 15 is affixed to tubular post 10 so that they behave 
as one inseparable mechanical unit. The function of the locking mechanism 
is such as to allow several mechanical linkages to unfold from a compacted 
position as depicted in FIG. 2, and rotate to the desired orientation. The 
linkages form a closed loop when half length linkage 12b is pinned in 
place to saddle mount base 15. The closed loop functions to secure the 
bicycle when the linkages are threaded through the bicycle frame and 
wheels, for example. Further security is afforded when the loop is 
concurrently closed around a secure object such as a bike rack or the 
like. 
FIG. 2 shows the locking mechanism in the portable and retracted position. 
The lock components including the retractable hinge stop 11, half length 
linkages 12a and 12b, and the full length linkage 13, are preferably all 
contained within the lumen of the tubular post 10, except for a small 
portion left extending for grasping by the user. The retractable hinge 
stop 11 is slid up into the tubular post 10 in the direction of saddle 
mount base 15. 
The half length linkage 12a lies along the axis of tubular post 10 and is 
positioned relative to the hinge pin 14, and the walls of the tubular post 
10. 
The full length linkage 13 is vertically positioned wherein the upper end 
of the linkage is abutted against the ears 11a, 11b of retractable hinge 
stop 11 and is axially located along the tubular post 10 axis by the 
surrounding tubular post 10 walls. The full length linkage 13 is further 
constrained so that it remains perpendicular to half length linkages 12a 
and 12b. 
The half length linkage 12b is vertically positioned wherein the upper end 
of the linkage is abutted against the lower end of half length linkage 
12a, and axially located along the tubular post 10 axis by the surrounding 
walls of tubular post 10. 
By using the physical arrangement of components as depicted in FIG. 2, self 
containment of the locking mechanism and all its subcomponents is readily 
achieved according to the invention. Retractable hinge stop 11, half 
length linkages 12a and 12b, and full length linkage 13 are preferably all 
contained within the lumen of tubular post 10. In the event that 
additional length of the trapezoidal locking mechanism is desired, a 
substantial portion of linkages 12a, 12b and 13 may optionally be 
lengthened to extend from the lumen of tubular post 10. 
It is realized that necessary constraints to the movement of retractable 
hinge stop 11 must be provided to maintain a secure loop when the locking 
mechanism is in the locked position. The diameter of the cylindrical 
portion of retractable hinge stop 11 inherently restricts movement to only 
along the axis of tubular post 10 as depicted at A. Axial movement is 
limited, when in the retracted position, by the saddle mount base affixed 
to the upper end of the tubular post 10. Referring to FIG. 3, the lower 
limit of axial movement is achieved by the insertion of an annular tapered 
split ring 31, into the hinge stop groove 32. Hinge stop groove 32 is of 
sufficient depth to allow compression of annular tapered split ring 31 so 
that the outermost edge of the split ring can compress minimally to the 
inside diameter of tubular post 10. Near the lower end of the tubular post 
10, and on the inner diameter of said tubular post 10, a detente 30 is of 
a right triangle profile, with the angle of the hypotenuse equal to that 
of the profile of the annular tapered split ring 31. It will become 
apparent to those skilled in the art that upward axial movement of 
retractable hinge stop 11 is allowed provided proper alignment of half 
length linkage 12a, while downward axial movement of said retractable 
hinge stop 11 is limited when the annular tapered split ring 31 
decompresses to fill the expansion of tubular post detente 30. This 
limitation of movement is a necessary mechanism to provide security while 
in the locked position, and retractability while in the transport 
position. 
FIG. 3 also depicts the positioning of half length linkage 12a with respect 
to hinge pin 14 and retractable hinge stop 11. Based on the length of 
retractable hinge stop 11, the relative affixment of hinge pin 14, and the 
clearance provided, half length linkage 12a is minimally rotatable to and 
position between the 3 o'clock and 9 o'clock positions. 
Referring to FIG. 4, saddle or seat mount base 15 is permanently affixed to 
tubular post 10 by any one of several different means such as a weldment, 
interference fit, permanent clamping device, or other means well known to 
those skilled in the art. The seat mount base 15 functionally provides a 
mounting structure to which a saddle 43, through its interim clamping 
structure, can be attached. The saddle mount base 15 also provides the 
housing structure necessary to capture half length linkage 12b when 
required for the locked position. To achieve a permanent attachment of the 
saddle 43, a through hole with a counter bored end 48 is provided for 
clearance of a typical socket head screw. A saddle mount clamp screw 47 is 
inserted through saddle mount base screw bore 48, saddle mount bracket 44, 
and threaded into saddle mount bracket clamp 45. A saddle support frame 46 
supplies integral rod members which in turn are clamped by rotational 
tightening of saddle mount clamp screw 47. Since an object of this 
invention is to provide security against theft of the saddle 43, the 
saddle mount clamp screw head is intentionally rendered inaccessible when 
the clevis shaped pin lock body 40 is in its depicted secured position. 
The saddle mount base 15 contains a mortised slot to the lower rear portion 
of its structure to accommodate the passage of half length linkage 12b 
into the mortised slot. Upon proper alignment of half length linkage 12b 
with a through hole provided in saddle mount base 15 accommodating pin 
lock pin 41, the insertion and locking of pin lock pin 41 secures half 
length linkage 12b in saddle mount base 15. The locking of the pin lock 
achieves closure to the trapezoidal locking mechanism according to the 
invention, thus integrally securing the saddle and bicycle around which it 
is intended to be looped. 
Pin lock body 40 is a removable channel structure through which passes pin 
lock pin 41. The pin lock pin 41 passes through one wall of the channel 
and locks within the other. By carefully designing the outer shape of 
saddle mount base 15 to match the channel dimensions of the pin lock body 
40, a custom matching snug fit can be achieved, thus eliminating 
extraneous rattling noise. Also critical to the security function of the 
locking device, is assuring correct positioning of the pin lock body 40 
over the head of the aforementioned saddle mount clamp screw 47. Desired 
correct positioning is simply achieved by extending the outer shape of 
saddle mount base 15 so that any pivot or rotation of pin lock body 40 
about pin lock pin 41 is constrained by the inherent interference in the 
channel of the pin lock body. 
Referring to FIG. 5, the use of the integral post locking mechanism is 
demonstrated as it may used to secure a bicycle to a rigid post such as a 
street lamp 58 or the like. The bicycle includes the usual bicycle frame 
50 to which are mounted a pair of bicycle wheels 52 and 54 and handle bars 
56. The proportioning of the post length and the corresponding linkages is 
optimally capable of including a primary bicycle frame member and 
minimally one wheel while having adequate space left within the 
trapezoidal loop for encircling the rigid post. 
An alternative bicycle locking mechanism according to the invention is 
shown in FIG. 6. This locking mechanism uses an elongated cable as the 
collapsible securing element rather than a firm linkage described 
hereinabove. The linkages 12a, 12b, and 13 of FIG. 1, are all replaced by 
a single cable of substantial strength with a loop or other means of 
affixment on each end 61a and 61b. The loop 61a is pinned using hinge pin 
14, while loop 61b remains unattached until it is desired to achieve the 
locked state. To achieve the locked state, loop 61b is inserted into the 
mortised slot of saddle mount base 15, and pin lock pin 41 is inserted in 
the loop 61b and subsequently locked, thus securing the cable to saddle 
mount base 15. Similarly to the structure shown in FIG. 2, the cable 
configuration is substantially contained within the lumen of the tubular 
post 10 when stored in the transporting position. To achieve the minimal 
required length of the cable 60, which must be greater than the length of 
tubular post 10, cable 60 can be doubled over as shown in FIG. 7 provided 
the cable diameter is less than half the inside diameter of tubular post 
10 or the cable can be spiralled into coiled segments as shown in FIG. 8. 
The design considerations regarding strength, flexibility, cost of 
manufacture, and containment yields a preferred configuration of either 
rigid linkage of FIG. 1 or the pliable cable method of FIG. 6. 
It will now be apparent to those skilled in the art, that this form of 
integral saddle post locking mechanism provides inherent portability, 
security, possible reduction in weight, integral attachment of the seat 
post and saddle itself while in the locked state, reduction in visual 
distractions from the intended aesthetic look of the bicycle, and 
reduction in mechanical bulk which can potentially interfere with cycling 
and/or induce unwanted rattling while cycling. While several preferred 
embodiments of the novel integral saddle post locking mechanism according 
to the invention have been described in detail herein, many variations and 
modifications are possible as will readily occur to those skilled in the 
art.