Lock arrangement employing mechanically acting code card and key card

In a lock apparatus having a lock housing and a locking member slidable in said lock housing between a locked and an unlocked position and a plurality of bores in both said lock housing and said locking member which are aligned when said lock apparatus is in a locked position, a plate-like code member having regions corresponding to said bores, at least one of said regions having a hole therein, a plate-like key member having regions corresponding to said bores, said regions having holes therein corresponding to said regions of said plate-like code member having no holes therein, the improvement comprising:

• a bullet-shaped upper blocking member positioned in each of said bores in said lock housing;
• each said bore having either a lower blocking pin or a lower ball therein, with at least one said bore having said lower blocking pin;
• a spring means acting to push said lower blocking pin or said lower ball against the bottom of said bullet-shaped upper blocking pin;
• a plate-like master member having regions corresponding to said bores, said regions having holes corresponding to said bores having lower balls and the same combination of holes or no holes as said plate-like code member for said bores having lower blocking pins.