Lock set with improved spindle mechanism

A lock set for use in combination with a deadbolt comprising:

• an outer knob assembly having an outer knob incorporating a key-operated lock member and a tubular member axially extending inward from an inner end of said outer knob assembly:
• an inner knob assembly having an inner knob incorporating a turning button means;
• a deadbolt-actuating hollow shaft connected to said inner and outer knob assemblies so as to be rotated thereby, said shaft having a pedestal extending into said tubular member;
• a spindle connected to said key-operated lock member and said turning button means, said spindle passing through said tubular member and said deadbolt-actuating hollow shaft;
• and
• a limit plate means provided in said tubular member adjacent to said pedestal and sleeved around said spindle, said limit plate means being movable diametrically, upon rotation of said spindle, between a locking position and an unlocking position,
• wherein said pedestal is further provided with a push means to transmit a push force to said limit plate means so as to move the limit plate means in a diametral direction to said unlocking position by rotating said inner knob assembly after the limit plate means has been placed in said locking position by turning said turning button means, and wherein said limit plate means includes a cam means to receive said push force when said inner knob assembly is rotated so as to cause said limit plate means to move to said unlocking position during the pushing operation of said push means whereby with the outer knob assembly locked by said limit plate means, rotation of the inner knob assembly produces unlocking of the outer knob assembly, said limit plate means also having a spindle pushing means so as to push said spindle to return to its original position when the limit plate means is moved to its unlocking position upon rotation of the inner knob assembly.