A side bar type cylinder lock with a variable key code comprising:
- a sleeve-like casing (1) provided with both a side bar holder engaging concave portion (2) and a side bar engaging concave portion (5) in an inner peripheral surface of said casing (1);
- a plug (6) rotatably, but not axially slidably, mounted in said sleeve-like casing (1), wherein said plug (6) is provided with:
- a keyhole (7) which opens into a front surface of said plug (6) to axially extend in said plug (6);
- a plurality of tumbler insertion holes (8) each intersecting said keyhole (7) of said plug (6);
- a side bar holder receiving hole (9) formed in one of opposite sides of said tumbler insertion hole (8);
- and, a spring receiving hole (10) formed in the other of said opposite sides of said tumbler insertion hole (8);
- a plurality of tumbler plates (11) each slidably mounted in said tumbler insertion hole (8) of said plug (6), wherein:
- said tumbler plate (11) has one of its opposite side surfaces formed into a side end portion (26) provided with a side bar engaging concave portion (12);
- and, said tumbler plate (11) has the other of said opposite side surfaces formed into an engaging portion (13);
- a plurality of variable tumblers (14) each slidably mounted in said tumbler insertion hole (8) of said plug (6), wherein said variable tumbler (14) has one of its opposite side surfaces formed into a saw-toothed engaged portion (15) capable of detachably engaging with said engaging portion (13) of said tumbler plate (11), wherein said variable tumbler (14) has its central portion provided with a key passing hole (17) communicating with said keyhole (7);
- a spring (18) received in said spring receiving hole (10) of said plug (6) to resiliently bias said variable tumbler (14) toward said inner peripheral surface of said sleeve-like casing (1);
- a side bar holder (19) slidably mounted in said side bar holder receiving hole (9) of said plug (6), wherein:
- said side bar holder (19) has one of its opposite surfaces bulged outwardly and formed the thus bulged surface into a bulged portion (21) and has its central portion provided with a side bar receiving hole (20);
- and, when said plug (6) is rotatably driven relative to said sleeve-like casing (1), said bulged portion (21) enters said side bar holder engaging concave hole (2) of said sleeve-like casing (1) to engage with said side bar holder engaging concave hole (2);
- a side bar (22) slidably mounted in said side bar receiving hole (20) of said side bar holder (19), wherein:
- said side bar (22) has its front end portion (23) biased in a biasing direction toward said side bar engaging concave portion (5) of said sleeve-like casing (1) so as to engage therewith;
- and, when said plug (6) is rotatably driven relative to said sleeve-like casing (1), said side bar (22) is moved in a direction opposite to said biasing direction of said side bar (22) to have its proximal end portion (24) engaged with said side bar engaging concave portion (12) of said tumbler plate (11);
- and
- a spring (25) for biasing said tumbler plate (11) toward said side bar holder (19), wherein:
- when said plug (6) is rotatably driven relative to said sleeve-like casing (1) to have said bulged portion (21) of said side bar holder (19) oppositely disposed from said side bar holder engaging concave portion (2) of said sleeve-like casing (1), said spring (25) resiliently forces said side end portion (26) of said tumbler plate (11) to enter said side bar holder receiving hole (9) of said plug (6), and resiliently forces said bulged portion (21) of said side bar holder (19) to enter said side bar holder engaging concave portion (2) of said sleeve-like casing (1), and further resiliently forces said engaging portion (13) of said tumbler plate (11) to disengage from said engaged portion (15) of said variable tumbler (14).