Magnetic-coded lock

A magnetic-coded lock is a lock device that uses pins in combination with magnets to prevent entry by either non-matching keys by teething or magnetic polarity. Magnetic-coded locks encompass knob locks, cylinder locks, lever locks, and deadbolt locks as well as applications in other security devices.

History

The magnetic-coded lock was invented by an engineer in Nanchang, China. There have been several Chinese patents taken out on this technology. The improved version of this technology is currently on patent pending status granted by US Patent and Trademark Office.

Design

Magnetic-coded technology utilizes multiple pairs of magnetic pins with opposing poles that are embedded inside keys and plugs. When a correctly matched key is inserted into the lock, not only are all the mechanical pins pushed into the correct positions, the magnetic pins are also driven to the appropriate level by the magnetic force inside the key.

The magnetic pins are made with permanent magnets which means the magnets stay magnetized. The intensity of the magnet will not decay over time or be affected by other magnetic fields.

Operation

In order to open a magnetic-coded lock, three criteria must be met: correct teething of the key, magnetic pin locations and poles of the magnetic pins. If any of these three criteria are not satisfied, the lock stays inoperable and cannot be turned.

Equations

$N=C\cdot 4^{m}$

$N$ - Magnetic-coded lock key combinations

$C$ - Conventional pin-tumbler lock combinations

$m$ - Pairs of embedded magnets. (multiple pairs can be embedded)

Features

Advantages

• Anti-picking:

The embedded magnetic pins are not exposed to the key way, therefore, no lifting force can be applied to move the magnetic pins. Most standard forms of lock picking are therefore preventable.

• Anti-bumping :

Lock bumping transmits kinetic energy from the key to the drive pins, to split the bottom and top pins. The embedded magnetic technology has no physical contact points between key and magnetic pins, therefore no kinetic energy is transmitted.

• Key control:

Due to the magnetic cylinder elements embedded in the keys, there is a high degree of key control. Unlawful key duplications are minimized by limited access to key blanks (locksmiths) and unique magnetic coding in the key that cannot easily be determined by inspecting the target lock.

• Cost Effectiveness :

Because the manufacturing process is based on the pin and tumbler platform, the cost of manufacturing is significantly reduced when compared to high security locks with comparable security features. These high security locks often utilize new locking mechanisms which increase the cost of manufacturing.

Disadvantages

• Manufacturing Complexities:

A special tool set and procedures have to be developed to accomplish the task of embedding the magnets inside both the keys and the locks.

• Key Control:

While one advantage is having a limited supply of blanks, it is also a huge disadvantage. One may have difficulty in duplicating the keys. If one loses a magnetic key, they will struggle to achieve a duplicate - and ultimately enter through the lock.

Installation

• The same as conventional lock installation. Drilling with hole saw may be required in doors lacking a hole for assembly.

References