Magnetic lock with auxiliary mechanical locking or resistance

A door lock, comprising:

• a backing plate that is mountable to a door frame;
• an armature that is mountable to a door and having a front face, the armature including a pin extending from the front face, the pin including a recess in the form of a groove provided about a shaft of the pin;
• an electromagnet moveably mounted to the backing plate for relative movement with respect to the backing plate and operating by electromagnetic attraction to the front face of the armature;
• a sleeve fixedly mounted to the backing plate and including a plurality of locking elements;
• a shoulder surrounding the sleeve, and configured to move with the electromagnet;
• a mechanical lock comprising the pin, the sleeve, the shoulder, and the plurality of locking elements;
• the mechanical lock operating by movement of the shoulder with respect to the sleeve which causes engagement of the plurality of locking elements with the groove of the pin;
• the electromagnet movable with respect to the backing plate between a locked position, where the shoulder engages the locking elements with the groove to thereby engage the mechanical lock, and an unlocked position;
• the electromagnet spring-biased to the unlocked position;
• if an attempt is made to push open the door when the electromagnet is active, then the attraction of the electromagnet to the armature causes movement of the electromagnet along with the armature so that the electromagnet moves to the unlocked position which causes movement of the shoulder with respect to the sleeve to thereby cause the mechanical lock to operate to resist opening of the door;
• and
• if an attempt is made to open the door when the electromagnet is deactivated then the mechanical lock does not operate and thereby allows the door to be opened.