Key-less combination cylinder lock, and a combination-changing tool

A lock operable by a combination comprising:

• a stator having a cavity;
• a rotor rotatably mounted within said cavity of said stator;
• a latch mounted to said rotor;
• at least one locking member interposed said rotor and said stator, said at least one locking member slidable between a locking position in which said rotor is fixed relative to said stator and a release position in which said rotor may be rotated relative to said stator;
• a declutching member slidably mounted to said rotor for axial movement between an enclutching position and a declutching position;
• a plurality of coaxial coding elements mounted within said rotor, each of said plurality of coding elements having an outer ring and a concentric central disk, said outer ring having an outside peripheral portion, said outside peripheral portion having a notch for receiving said locking member, said central disk having means for rotatably driving an adjacent coding element when said central disk is rotated, said central disk further having a circumferential edge portion adapted to be received within said outer ring in a multiplicity of predetermined relative angular positions, said central disk mounted to said declutching member for axial movement when said declutching member is moved between said enclutching position and said declutching position;
• a rotary element decoding member mounted within said stator having means for rotating one of said plurality of coding elements to bring said notch of said outer ring of each of said plurality of coding elements into alignment to accept said locking element in said release position;
• at least one first spacer disposed between each said outer ring of said plurality of coding members, and between said decoding member and one outer ring of said plurality coding members, each of said at least one first spacer establishing a predetermined axial gap between said outer ring such that, when said central disks are in said declutching position, each central disk is rotatably positioned in each said axial gap and rotatable relative to its respective outer ring when said declutching member and each said central disk are in said declutching position for changing the combination of the lock.