SYSTEM AND METHOD FOR LOCKING A BICYCLE CHAIN

A system and method for detachably locking an apparatus onto a bicycle chain to prevent rotation of the chain over the sprocket and thereby prevent theft of the bicycle.

TECHNICAL FIELD

This disclosure relates to a lock that is secured to the chain of a bicycle to interfere with movement of the chain around the sprocket thereby preventing the propulsion of the bicycle forward using the bicycle crank.

BACKGROUND

Bicycle theft is typically seen as a low police priority, its impact and magnitude often overlooked because police consider incidents on a case-by-case basis. This picture is often misleading, however, and when viewed at the aggregate level, bicycle theft represents a much larger problem, one with harmful economic and societal effects that warrant greater police attention.

The bicycle has become increasingly popular as a healthier and environmentally friendlier mode of transport. In London, for example, cycle use has increased by 83 percent between 2000 and 2007. In the United States, between 1992 and 2006, bicycle sales have increased from 15.3 million to 18.2 million per year (an increase of roughly 20%), illustrating an increase in cycle use there. While cycles enjoy the greatest share of transit options within campus towns, several major towns and cities such as Portland, Oreg., are continually improving cycling infrastructure to encourage cycling. Moreover, anticipating consumer demand, General Motors has developed the Flex-Fix system, a retractable bicycle rack that is hidden in a car's bumper. These changes in bicycle usage and provision have been influenced in recent years by:

increased awareness of the detrimental effect of automobile carbon dioxide emissions, and pursuit of air quality and emission reduction targets;

concerns over growing traffic congestion and accompanying noise pollution;

rising levels (and fear) of obesity and heart disease;

recognition that most trips are relatively short, or “bike-sized”;

savings in road maintenance and improvement of street infrastructure; and

responses to policies such as traffic congestion charging.

Several studies suggest that fear of cycle theft may discourage bicycle use, and that many bicycle theft victims do not buy a replacement. Combating bicycle theft is therefore a necessary step toward increasing the use of this sustainable form of transport, an increase that unexpectedly may also improve cyclist safety. To elaborate, a recent international review of schemes to encourage walking and cycling found strong evidence indicating that as the number of cyclists and walkers increased, the frequency of collisions between those groups and motorists decreased. The authors concluded that an effective means of improving the safety of cyclists and walkers is therefore to increase the numbers of people cycling and walking. Despite this, little attention has been paid to the prevention of bicycle theft. Car theft has received much more attention, for example, yet according to data collected as part of the International Crime Victim Survey, for all countries for which data were available (including the United States), bicycle owners are far more likely to have their bikes stolen (4.7%) than car owners their cars (1.2%) and motorcyclists their motorcycles (1.9%).

Understanding the problem of bicycle theft is hampered because police data typically underrepresent the problem. This is illustrated by data from the International Crime Victim Survey (2000), which show that across the 17 countries surveyed (including the United States), on average only 56 percent of bicycle thefts were reported to the police. U.S. crime statistics are collated using both National Crime Victim Survey (NCVS) data from a yearly national survey, and data recorded by the police. Comparing the two data sources highlights the problem of underreporting. For example, in 2004, bicycle theft accounted for 3.6 percent of all incidents of larceny (Federal Bureau of Investigation, 2005), which equates to more than 250,000 bicycles stolen each year. According to an estimate from the NCVS, in 2006 the number of incidents of theft-of or theft-from bicycles was more like 1.3 million (just under 2.5 incidents per minute). This suggests that for every crime reported, another four (or more) may have occurred.

Interviews with bicycle theft victims indicate that underreporting is largely due to victims' belief that the police are not interested in bicycle theft and cannot do anything about catching the offender and returning the stolen bicycle. A further reason for an underrepresentation of the problem is that police departments record bicycle theft in different ways that, however inadvertently, may serve to conceal the full scope of the problem. For example, police may record a bicycle theft as a burglary from a residential property.

Generally, when you come out and you find nothing but a busted lock where your bike used to be, the chances of being reunited with it are slim. Nationwide, less than half of stolen bicycles are recovered by police and barely 5 percent are reunited with their owners.

It is difficult to determine the precise number of stolen bicycles, because most bicycle theft is never reported to law enforcement. Over two million bicycles are stolen each year in the U.S. and Canada. Out of those, only 20 percent are ever reported to the police as stolen. The theft of two million bicycles was originally believed to be worth some $50 million, but now estimated to be a billion-dollar problem.

Another reason theft is so prevalent is that locks haven't kept pace with the times. The ones that do work can be so expensive or so heavy that they deter people from riding in the first place. GPS trackers can locate a stolen bike, but do nothing to stop thieves who only want to strip its parts.

SUMMARY

In accordance with preferred embodiments of the device disclosed herein, some of the problems associated with bicycle locks are overcome.

In order to combat the increasing scourge of bicycle theft the apparatus disclosed herein repurposes the method of use of the invention under U.S. Pat. No. 3,624,945 titled Universal self-conforming trigger lock for firearms. The system and method for subverting the theft of bicycles requires the application of the locking mechanism disclosed herein to the chain of a bicycle. Once applied to the chain and locked in position onto the chain, the capacity to propel the bicycle using the locomotion hardware to include the pedals, sprockets and chain becomes extremely limited, if non-existent. Once the locking mechanism is applied to the chain, the chain cannot engage with the sprockets of the front carriage or the sprockets of the rear wheel cassette or navigate past the derailleur. Any attempt to force the locking mechanism around either the front carriage sprockets or the rear wheel cassette will result in either slippage of the chain off the sprocket, a seizing of the chain sprocket assembly in place and/or damage to the front and rear derailleurs.

These and other objects of the chain lock disclosed herein, which will become apparent hereinafter, are achieved by providing a lightweight and compact lock that secures to the chain of a bicycle preventing rotation of the chain around the sprocket due to interference between the lock and the sprockets and derailleurs.

It is therefore an object of the lock disclosed herein to be of sufficient mass to functionally inhibit normal operation of the bicycle by preventing rotation of the chain.

It is a further object of the lock disclosed herein to be fabricated from components that are sufficiently robust to prevent utilization of typical household tools to remove the lock from the chain.

These, together with other aspects of the lock disclosed herein, along with the various features of novelty that characterize the technology, are pointed out with particularity in the claims annexed hereto and form a part of this disclosed technology. For a better understanding of the disclosed technology, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated exemplary embodiments of the disclosed technology.

DETAILED DESCRIPTION

Disclosed herein are a system and method for preventing the theft of bicycles, and conceivably any chain driven apparatus, by the application of the locking device so disclosed and described.

FIG. 1illustrates a perspective view of the locking apparatus10in isolation.FIG. 2illustrates the locking apparatus10as applied to a span12of chain14of a bicycle16. Referring again toFIG. 1, the locking apparatus10is fabricated from first and second locking members18,20. The first locking member18has an inner face24and an outer face26as well as an outer perimeter surface30. The second locking member20also has an inner face32, and outer face34and a perimeter surface36. The locking members18,20are preferably fabricated from a material such as stainless steel that is capable of withstanding extreme environmental conditions without oxidizing and capable of withstanding the application of cutting forces from a saw or bolt cutter as well as capable of withstanding impact loads from a hammer.

As illustrated atFIG. 3, a cylinder40extends outwardly from the first locking member18. The cylinder40comprises a longitudinally extending open face, or cutaway42. The arc of the cutaway42is preferably in the range of 110 to 160 degrees which facilitates engagement with another component that is described in detail below. The cylinder40preferably has a wall thickness T that provides sufficient strength to prevent undesirable bending when the locking apparatus10is placed under a heavy load, such as that applied by a thief attempting to liberate the bicycle from the rightful owner. The cylinder40also preferably utilizes a cap44that extends over most of the upper surface area of the cylinder40. The base50of the cylinder40is preferably press-fit into an opening52in the inner face24of the first locking member18. Once press into the opening52, the cylinder40is securely maintained in position.

FIG. 4illustrates an exploded assembly view of the locking apparatus10revealing the placement of a rotatable shaft54within the cylinder40. The rotatable shaft54is observable from the open face42of the cylinder40. The shaft54includes an upper end56and a lower end58. The upper end56is disposed immediately beneath the cap44that extends over the cylinder40. A portion of the total circumference of the shaft54from the upper end56to the lower end58includes striations62. The striations62are preferably lateral cuts in the shaft54that are uniform and equally spaced along the entire length of the shaft. As seen inFIG. 5, each of the striations62also preferably include an overhang66that may be faced upwardly or downwardly but all striations on the shaft are uniform in direction of facing. Oppositely directed striations (up and down) facilitate the locking action that is necessary to prevent separation of the first and second locking members.

FIG. 4reveals the locking mechanism70that is securely housed within a housing H that also includes an upper lip L. The housing H extends outwardly from the outer face26of the first locking member18. The locking mechanism70protected within the housing H is operable to rotate the lower end58of the shaft54. The locking mechanism70as well and the attachment structure between the locking mechanism and the shaft54are well known in the industry and are described with enabling disclosure in U.S. Pat. No. 3,624,945. The locking apparatus10preferably utilizes a key71to lock and unlock the locking mechanism70. As with any standard lock found in many applications, the key71is rotated in one direction to lock the apparatus10and the opposite direction to unlock the apparatus.

Also illustrated atFIG. 4is a spacer rod72with a distally located outer contact surface74. The spacer rod72extends outwardly from the inner face24of the first locking member18and is preferably disposed proximate the cylinder40. The preferred gap between the spacer rod72and the cylinder40is sufficient to position the span12of the bicycle chain14therein. The spacer rod72is preferably press fit into a predrilled hole in the inner face24of the first locking member18. It is also contemplated by this disclosure that more than one spacer rod72,72A may be employed to provide enhanced robustness to the locking apparatus10thereby increasing the level of effort required by a thief to defeat the lock. In addition, supplemental spacer rods72B,72C may optionally be disposed on the opposite side of the cylinder40.

FIG. 6illustrates an opening76extending through the second locking member20for passage therethrough of the cylinder40. The opening76in the second locking member20includes an interior surface80. Extending longitudinally along the interior surface80of the opening76is a striated plate84. When the locking apparatus10is in operation the striated plate84is utilized for locking engagement with the striated surface of the shaft54. The striations85on the plate84are oppositely directed from those of the striations62on the shaft54. When the striations are oppositely directed from one another as they are on the shaft54and the striated plate84the striations can engage and interlock with one another so that the first and second locking members18,20cannot be withdrawn from one another until the striations62on the shaft54are rotated away from the striations85on the striated plate84.

In operation, the lock operator seeks to apply the locking apparatus10to a span12of chain14of a bicycle16. The chain14for purposes of the apparatus disclosed herein circumscribes a front sprocket and a rear sprocket of the bicycle16. The operator then places the span12of the bicycle chain14between the at least one spacer rod72and the outwardly extending cylinder40. The cylinder and the spacer rod40,72restrain the chain span12to movement along a linear path but do not fully restrain the chain span12thereby allowing the first and second locking members18,20to complement restraint of the chain span12in position.

To fully enclose the chain span12between the first and second locking members18,20the cylinder40is received into the opening76of the second locking member20. As previously detailed above, the opening76in the second locking member20includes an interior surface80. Extending longitudinally along the interior surface80of the opening76is a striated plate84. As the cylinder40is advanced into the opening76of the second locking member20, the striations62on the shaft54housed within the cylinder40may be rotated such that there is no contact between the shaft striations62and the striations on the plate84. Lack of contact between the two striated surfaces occurs when the locking mechanism70is rotated away from the open face, or cutaway42, effectively hiding the striations62from contact. Alternatively, the shaft striations62may remain within the open face42and the cylinder40may readily slide into the opening76. Any attempt to withdraw the cylinder40is not be possible as the shaft striations62have engaged with the oppositely directed striations85of the striated plate84.

Once the distally located outer contact surface74of the spacer rod72contacts the inner face32of the second locking member20the cylinder40and the enclosed shaft54are seated thereby fully restraining the chain span12in position between the first and second locking members18,20. Rotating the locking mechanism70, with the key71, rotates the shaft54housed within the cylinder40for interlocking engagement of the striations62upon the shaft54with the striations85upon the striation plate84. This interlocking engagement of the two striated structures secures the span of chain12in position between the first and second locking members18,20as well as between the cylinder40and the at least one spacer rod72.

It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.