The present invention relates to pin tumbler cylinder locks and to anti-tampering arrangements for pin tumbler cylinder locks.
The pin tumbler cylinder lock has been used since the mid-19th century to restrict unauthorized access to an item, an enclosure, or a location, for example, as a door lock. A conventional pin tumbler cylinder lock 10, as shown in
The conventional pin tumbler cylinder lock may be susceptible to unauthorized opening. As one example, lock picking involves the use of thin picks inserted in the keyway to manipulate the driver and tumbler pins to position the pins for rotation of the plug. As another example, as illustrated in
The present application contemplates various inventive features for a pin tumbler cylinder lock that, alone or in combination, may impede unauthorized access to a locked structure by bumping the lock. According to an inventive aspect of the present application, a pin tumbler cylinder lock may be adapted such that at least one driver pin and/or tumbler pin in the lock remains extended across a shear line between a plug and a shell of the lock during a bumping operation, such that rotation of the plug with respect to shell is blocked. In one embodiment, the lock may be configured such that the portion of the impact of a bump key (or other such tool) during a bumping operation that is translated into movement of the corresponding driver pins is reduced, thereby impeding movement of the driver pins out of the corresponding plug channels to maintain blocked rotation of the plug with respect to the shell.
Accordingly, in one embodiment of the present application, a pin tumbler cylinder lock includes a shell, a plug, and at least first and second tumbler pins and first and second driver pins. At least the first driver pin extends into a corresponding plug channel when the plug is in a locked condition, such that rotation of the plug with respect to the shell is blocked. The lock is configured such that at least the first driver pin is separated from the first tumbler pin by a gap when the plug is in the locked condition. the first and second tumbler pins are raised without the proper key and the gap between the first tumbler pin and the first driver pin is eliminated, the second tumbler pin extends across the shear line and into the corresponding shell channel.
Features and advantages of the invention will become apparent from the following detailed description made with reference to the accompanying drawings, wherein:
This Detailed Description of the Invention merely describes embodiments of the invention and is not intended to limit the scope of the invention in any way, Indeed, the invention as described in the claims is broader than and unlimited by the preferred embodiments, and the terms used in the claims have their full ordinary meaning.
The present application contemplates a pin tumbler cylinder lock arrangement configured to inhibit or deter unauthorized operation of a lock by bumping, for example, with a bump key or pick gun. According to an inventive aspect of the present application, a pin tumbler cylinder lock arrangement may be configured such that a gap is provided between at least one of the tumbler pins and the corresponding driver pin when the lock is in a locked or pre-bump condition. As a result, when the tumbler pin is bumped, a significant amount of the kinetic energy produced is used first to cause the tumbler pin to travel across the gap and move into contact with the corresponding driver pin before any energy is applied to move the driver pin. Further, the resultant force of impact on the driver pin is supplied only by the relatively low mass tumbler pin, instead of by the key and tumbler pin together or in contact with each other. As a result, the bumped tumbler pin is unable to bump the driver pin out of the plug channel. At the time when the tumbler pin and driver pin are in contact, the driver pin continues to span the shear line between the plug and the shell.
Many different configurations may be used to provide a gap between a tumbler pin and a corresponding driver pin in a pin tumbler cylinder lock arrangement. In one embodiment, an outer surface of the driver pin and/or an inner surface of the plug and or shell channels may be shaped or sized to limit the portion of the driver pin that may be received in the plug channel, resulting in a gap between the driver pin and the tumbler pin. In an exemplary embodiment, the pin and channel arrangement is configured such that the driver pin extends approximately 0.025 to 0.040 inches (0.64-1.02 mm) into the plug channel from the shear line between the plug and the shell. It should be apparent to one of ordinary skill in the art that other dimensions may be used in the practice of this invention.
In some embodiments, as shown, for example, in
In other embodiments, as shown, for example, in
In still other embodiments, as shown in
Interference between the plug 320 and the main portion of the exemplary driver pin 339 provides a gap G between the driver pin and the tumbler pin 329 (as shown in
While many different sized gaps between a tumbler pin and a driver pin may be utilized to inhibit bumping of the driver pin 339 by the tumbler pin 329 into the shell channel 335, in one embodiment, the gap may be dimensioned such that when a peak portion P of a conventional bump key K is aligned with the tumbler pin, a gap G′ remains between the tumbler pin 329 and driver pin 339 (as shown in
A bump key with “taller” peaks P may narrow or eliminate the gap between the tumbler pin 329 and driver pin 339 when the peak P is aligned with the tumbler pin 329 (i.e., in a “bumped” position), which may increase the susceptibility to bumping of the gap enabling driver pin 339 beyond the shear line S. However, such a tactic may be effectively countered, for example, by providing one or more longer tumbler pins 329c (e.g., a code 2 or 7 tumbler pin) in one or more of the other plug channels 325. In such an embodiment, a bump key K having peaks P tall enough to eliminate the gap between the tumbler pin 329 and the gap enabling driver pin 339 in the bumped position would also extend the longer tumbler pin 329c above the shear line S between the plug 320 and the shell 330, as shown in
Since the exemplary tumbler pin 329, when bumped, separates from the bump key K before the tumbler pin 329 impacts the driver pin 339, the relatively low mass of the tumbler pin (compared to the key and tumbler pin in contact with each other and impacting the driver pin together) results in a reduced impact force on the driver pin, thereby inhibiting movement of the driver pin out of the plug channel. According to another inventive aspect of the present application, unauthorized operation of a lock by bumping may be further impeded by reducing the mass of the tumbler pin associated with the gap enabling driver pin, while maintaining the desired length of the tumbler pin, further reducing the impact force on the driver pin.
Many different configurations or methods may be utilized to provide a tumbler pin with a reduced mass per unit length, including, for example, use of a lower density material, such as plastic or aluminum (instead of brass or steel), or use of pins having portions of material removed, such as hollow or necked down configurations. In an exemplary embodiment, as illustrated in
The narrower or stepped portion of the gap enabling driver pin 339 may comprise a number of different contours, tapers or shapes. In one embodiment, the end portion may be shaped to provide a radial gap between the driver pin 339 and the edge of the plug channel 325. This radial gap may be provided, for example, by a driver pin 339 having a stepped portion 339′ with a radially outward lower portion extending from a tapered, necked down, or otherwise recessed portion of the stepped end, where the recessed portion aligns with the edge of the plug channel 325 when the plug 320 is in a locked condition. In the illustrated embodiments of
As one benefit of a reverse taper or other such configuration, when the lock is aggressively bumped, the radial gap R protects the edge of the plug channel 325 from deformation or chamfering caused by impact between the driver pin 339 and the edge of the plug channel 325. This type of damage may otherwise make the plug channel 325 more susceptible to dislodging of the driver pin 339. Also, if torque is applied to the cylinder plug 320 prior to bumping, the end 339′ of the driver pin 339 may engage or interlock with the side of the plug channel 325, thereby impeding axial movement of the driver pin 339 due to bumping. Further, aggressive bumping of the lock 300 may tend to cause the end 339′ of the driver pin 339 to mar or deform the inner surface of the plug channel 325 (i.e., inward of the channel edge), which may further impede dislodging of the driver pin 339 by bumping. Additionally, the marring or witness marks caused by aggressive bumping may provide visual evidence, upon disassembly of the lock 300, that unauthorized access by bumping had been attempted.
In one exemplary embodiment, all or part of the driver pin 339 may be provided in a more durable or wear resistant material (as compared to, for example, the plug 330 or to other driver pins in the assembly), such as, for example, stainless steel, such that the end 339′ of the driver pin 339 is less likely to wear or become damaged during such a bump attack. Additionally or alternatively, a driver pin 339 may be configured such that at least the end portion 339′ is harder than the material of the plug 320, such that the plug 320 (and not the driver pin end portion 339′ is worn due to aggressive bumping of the lock 300. For example, the driver pin 339 may be surface or through hardened to increase durability. As one example, a steel driver pin 339 may be heat treated at least at the end portion 339′ for increased durability of the plug channel engaging surfaces.
As another benefit of the reverse tapered end portion 339′, resistance to lock picking may be provided by the inclusion of an added step at the end of the driver pin 339, which may provide a false indication that a lock picking tool has engaged the edge of the tumbler pin 329 (similar to a spool-type driver pin, as known in the art). Further, as shown, the opposite end of the driver pin 339 may also include a tapered or contoured end portion 339″, which may, but need not, match the other end portion 339′. This may allow for assembly of the driver pin 339 in the key cylinder in either direction, for example, to improve assembly efficiency.
According to another inventive aspect of the present application, to inhibit separation of a driver pin from a plug channel due to bumping (either alone or in combination with one or more of the other bump inhibiting techniques described herein), a biasing force applied to the driver pin (such as by a spring) may be increased to counter the impact force of the tumbler pin against the driver pin. This biasing force may be increased using many different configurations or techniques, such as, for example, using additional or stiffer/stronger springs or using additional or different biasing components, such as a compressible plastic or elastomer components. According to another inventive aspect of the present application, as shown in
While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.
This application claims the benefit of the following U.S. Provisional Patent Applications, the entire disclosures of which are hereby incorporated by reference, to the extent that they are not conflicting with the present application: App. Ser. No. 60/903,112, entitled “Anti-Tampering Arrangements for Pin Tumbler Cylinder Locks” and filed Feb. 23, 2007; App. Ser. No. 60/1921,765, entitled “Anti-Tampering Arrangements for Pin Tumbler Cylinder Locks” and filed Apr. 4, 2007; App. Ser. No. 60/916,629, entitled “Anti-Tampering Arrangements for Pin Tumbler Cylinder Locks” and filed May 8, 2007; App. Ser. No. 60/1941,134, entitled “Anti-Tampering Arrangements for Pin Tumbler Cylinder Locks” and filed May 31, 2007; and App. Ser. No. 60/951,789, entitled “Anti-Tampering Arrangements for Pin Tumbler Cylinder Locks” and filed Jul. 25, 2007.
Number | Date | Country | |
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60903112 | Feb 2007 | US | |
60921765 | Apr 2007 | US | |
60916629 | May 2007 | US | |
60941134 | May 2007 | US | |
60951789 | Jul 2007 | US |
Number | Date | Country | |
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Parent | 12018528 | Jan 2008 | US |
Child | 13431244 | US |