A dual mechanism lock, comprising:
- a lock body having an opening formed therein, said lock body having adjacent first and second accommodating grooves formed in said opening;
- a key lock structure positioned in said second accommodating groove, said key lock structure including a) an external cylinder having a tubular contour rotatably disposed in said second accommodating groove, said external cylinder having an internal surface with at least one guiding groove formed therein, said external cylinder having a fixing groove formed on one side thereof and a recess formed in an opposing side, b) an internal cylinder located in said external cylinder and having a sliding member engageable with said guiding groove for rotation of said external cylinder with said internal cylinder, said internal cylinder having a protruded member extending from an one end thereof and an opposing end coupled to a knob, and c) a lock core disposed in said internal cylinder and being rotatable therein to retract said sliding member from engagement with said guiding groove responsive to insert and rotation of a key therein to thereby rotate said internal cylinder relative to said external cylinder;
- a lock tongue slidably disposed in a penetrating hole of said lock body and biased by a first spring, said lock tongue having a fixing groove formed therein, said protruded member of said internal cylinder being received in said fixing groove to displace said lock tongue within said penetrating hole responsive to rotation of said internal cylinder;
- a combination lock mechanism disposed in said first accommodating groove, said combination lock mechanism including a) a lock core rod slidably disposed in said first accommodating groove and having a plurality of protruded members extending therefrom, b) a plurality of fixing wheels rotatably coupled to said lock core rod, each of said fixing wheels having a concave groove for slidably receiving a respective one of said plurality of protruded members of said lock core rod therein responsive to said fixing wheels being rotated to an unlocking position where said concave grooves of said fixing wheels are respectively aligned with said plurality of protruded members of said lock core rod, said lock core rod being biased by a second spring to respectively position said plurality of protruded members external to said concave grooves of said fixing wheels, c) a plurality of combination wheels respectively mounted to said plurality of fixing wheels for rotation therewith, and d) a fixing plate disposed in said first accommodating groove and having a first lateral side disposed in said fixing groove of said external cylinder, said fixing plate having a pair of clips formed on second lateral side thereof, said fixing plate being fixed to said lock core rod by said pair of clips for displacement therewith;
- and,
- a panel covering said lock body and having openings formed therethrough for passage of a portion of said combination wheels and said knob therethrough, wherein said fixing plate locks said external cylinder against rotation until said fixing wheels are rotated to said unlocking position and said fixing wheels being respectively separable from said plurality of combination wheels for resetting a combination defined thereby responsive to said external cylinder being rotated to align said recess therein with an end of lock core rod for receiving said end of said lock core rod therein.