GB2429235A

GB2429235A - A pin tumber lock and a method for altering a lock

Info

Publication number: GB2429235A
Application number: GB0516863A
Authority: GB
Inventors: Jukka Talvio
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-17
Filing date: 2005-08-17
Publication date: 2007-02-21
Also published as: GB0516863D0

Abstract

A pin tumbler type lock comprises a shell, a plug rotatably disposed within the shell, the shell and the plug each having a corresponding plurality of holes which are aligned when the plug is in a given rotational position to provide a plurality of hole pairs, and a plurality of pin stacks each of which is located within a corresponding hole pair, the stacks being moveable within their respective hole pairs by a key to lock and unlock the lock. At least one of the pin stacks comprises at least three pin components and, in a locked configuration, a first of the pin components is located wholly within the plug. A second of the pin components extends across the junction between the plug and the shell, and a third of the pin components is located wholly within the shell. A method for altering a pin tumbler type lock to resist a key bumping operation, the method comprising replacing at least one of the pin stacks of the lock with an alternative pin stack comprising at least three pin components.

Description

Protection against impact picking mechanical locks

Background of the invention

The most typical commercial mechanical lock in the world is the so-called "pin tumbler lock". The reader has most certainly at some point used such lock. See figure I. There is the lock shell [6] inside which there is a rotating plug [7]. If one can rotate the plug using the key, or in some other way, one can open the lock. There are a varying number of pin stacks with at least two pin components in each stack. The pin components that extend across the shear line between the shell and the plug lock them together and prevent the plug from turning. See figure 1. The correct key pushes on the pin components and make pin components align with the sheer line [5] between the plug and the shell. See figure 2.

Morris Falk patented this type of lock in the US patent no US 1414348. Since then there have been a large number of variations and improvements to this lock. The number of pin stacks has varied. There are now locks that have pins stacks from two or more sides of the key. There are locks where some of the pin components are hollow and have another pin stack inside hollow pins. To enable master keys, there may be more than two pin components inside the pin chambers. See figure 3 and 4.

The pin component closest to the spring [1] comes below the sheer line [5] when the lock is in locked position. See figure 4.

There has for a long time been known methods for picking this kind of a lock. One of the most effective ones is the impact picking method: A pick gun or bump key [3] is inserted into the lock. This device then applies a sudden and instantaneous impact to : all the lower pins [2]. As in Newton's cradle * ..* (http://www.lhup.edwLdsimanekjscenario/cradle.htm), or billiard balls, the force of the impact is transferred through each pin stack to each corresponding second pin * component [1] that is then the only one that moves. The mass and resistance of the * *** springs are insufficient to prevent this movement of the second pin components. The :. result of the bumping is to create a gap between the pins, allowing turning of the plug inside the shell without the proper key. See figure 5.

* ... From these methods the picking gun is the most well known and most often used.

* :* Samuel Segal patented the lock picking gun in 1943 with US patent no US23 09677.

In 2004, Barry Wels and Rop Gonggrijp published a paper on a method that they call "bumping locks": http://www.t000l.nl/bumping.pdf The Dutch TV station Nova also made a program telling people about this method: http://www. toool.nl/bumpkey-alert.wmv. Before Wels' and Gonggrijp' s article bumping locks was not that well known a method even though Marc Tobias described it in his book Locks, safes and security (second edition), 2000, ISBN 0- 398-07079-2 on page 603. Mr. Tobias' book is the de facto standard encyclopedia of mechanical looks for hobbyists, locksmiths, law enforcement and the intelligence community.

Wels & Gonggrijp write that the lock bumping method has been known for more than years.

Bumping locks has proven to be much more effective a method than the picking gun.

It seems that most of the current normal and high security locks can be opened using bump keys. As Wels and Gonggrijp explain in their paper only certain fairly uncommon locks resist this method. Worryingly many of the locks that police and insurance companies recommend today can be opened using this method without leaving a mark on the lock.

In this description we use the term "impact picking" to refer to all the above methods of opening the lock without the key. They all have the common element of giving the first pin component an impact that is transferred to the pin component closest to the spring.

There are many inventions and methods used in the lock industry to prevent impact picking, but these have proven to be mostly ineffective against lock bumping. The lock designs that resist bumping are complex and expensive. This would also mean that millions of locks in the world should be replaced with a different make or model.

There has been no known economical lock design that would resist lock bumping.

Furthermore, there has not been any known method of upgrading the current lock designs to resist lock bumping.

Summary of the Invention

The invention is that at least one of the pin stacks comprises at least three pin components and, in a locked configuration, a first of the pin components is located wholly within the plug, a second of the pin components extends across the junction between the plug and the shell, and a third of the pin components is located wholly : .. within the shell.

*. :: In this respect, the lock system and method according to the present invention substantially departs from the conventional concepts and designs of the prior art, and * :* : :* in doing so provides an apparatus primarily developed for the purpose of making the * use of impact picking ineffective thereby precluding the opening of the lock without a * key.

* The apparatus is clearly innovative. The picking gun has been known for more than years. It is still used by many locksmiths in the original or motorized form to open : * locks when the key has been lost. There has been many complex apparatus and designs developed in the industry to protect against picking guns and bump keys, but no one has previously suggested the apparatus described in this invention even though the problem has been known for an extended period of time.

Therefore, it can be appreciated that there exists a continuing need for a new and improved impact picking resistant lock system and method that can be used for precluding the opening of the lock without a key.

In this regard, the present invention substantially fulfills this need.

Brief Description of the Drawings

Figure 1 illustrates in cross-section a conventional pin tumbler lock in a locked position; Figure 2 illustrates typical pin tumbler lock in an open position with the key inserted.

Figure 3 illustrates typical pin tumbler lock in an open position with the master key inserted Figure 4 illustrates the same lock as in figure 3 in a locked position.

Figure 5 illustrates the effect of a picking gun or similar impact picking device inside a pin tumbler lock that is also pinned for a master key.

Figure 6 illustrates the third pin component inside a pin tumbler lock.

Figure 7 illustrates the effect of a picking gun or similar impact picking device inside pin tumbler lock with an extra pin.

Figure 8 illustrates the effect of a picking gun or similar impact picking device inside pin tumbler lock pinned for a master key and with an extra pin component.

Figure 9 illustrates example shapes for the third pin component.

Detailed Description of Certain Embodiments

We propose adding an extra pin, ball or other weight as the last "pin component" to the lock so that the last pin component is not responsible for locking [4].

In a lock where the third pin component [4] is not responsible for locking the plug to L: : the shell, the impact picking device [3] is ineffective. It does move the last pin but * .. since the last pin is not required to keep the lock from opening, the lock will not open. ****

* It is certainly possible to design a new lock using this apparatus but what may be even * more valuable is that it may well be possible in many cases to add the extra pin to *:. existing locks. Locksmiths often open locks to re-key them. This involves changing * the first pin components [2] to fit a certain key. At the same time, if the pin chambers allow it, it is possible to add a third pin [4] to prevent impact picking. * S..

: * If and when there is no room in the pin chamber for the new pin, then the extra pin can be shaped so that it mostly fits inside the spring. See figure 9.

Claims

Claims: I. A pin tumbler type lock comprising: a shell; a plug rotatably

disposed within the shell, the shell and the plug each having a corresponding plurality of holes which are aligned when the plug is in a given rotational position to provide a plurality of hole pairs; and a plurality of pin stacks each of which is located within a corresponding hole pair, the stacks being moveable within their respective hole pairs by a key to lock and unlock the lock, wherein at least one of the pin stacks comprises at least three pin components and, in a locked configuration, a first of the pin components is located wholly within the plug, a second of the pin components extends across the junction between the plug and the shell, and a third of the pin components is located wholly within the shell.
2. A lock according to claim I, wherein each of the pin stacks comprises at least three pin components with said specified locations in the locked configuration.
3. A lock according to claim 1 or 2, wherein the or each pin stack having at least three pin components comprises only three pin components.
4. A lock according to any one of the preceding claims and comprising a resilient member disposed between the end of each hole within the shell and the top of the corresponding pin stack.

:
5. A lock according to claim 4, wherein said resilient member is a spring.
6. A lock according to claim 4 or 5, wherein the or each third pin component is fixed to an end of the corresponding resilient member.

* -::
7. A lock according to any one of the preceding claims, wherein the or each third pin component is substantially cylindrical.

*
8. A lock according to any one of claims 1 to 6, wherein the or each third pin * ** component is substantially spherical. . *
9. A lock according to any of the preceding claims, wherein a plurality of the pin components are located wholly within the shell.
10. A lock according to any of the preceding claims, wherein a plurality of the pin components are located wholly within the plug.
11. A method of altering a pin tumbler type lock to resist a key bumping operation, the method comprising replacing at least one of the pin stacks of the lock with an alternative pin stack comprising at least three pin components whereby, in a locked configuration, a first of the pin components is located wholly within the plug, a second of the pin components extends across the junction between the plug and the shell, and a third of the pin components is located wholly within the shell.