Push-button type cylinder lock assembly

A cylinder lock assembly comprising:

• an outer rose;
• an outer handle;
• an outer drive tube disposed rotatably within said outer rose and connected to said outer handle, said outer drive tube having an axially elongated aperture;
• a latch operating tube connected to a latch unit, and having an enlarged end portion that extends into said outer drive tube opposite to said outer handle, said enlarged end portion having a surrounding wall, and a protrusion projecting inwardly and radially from an inner surface of said surrounding wall;
• a locking spindle extending movably in said latch operating tube and having one end that is inserted into said surrounding wall and that has a locking tongue extending radially and outwardly through said aperture of said outer drive tube and movable axially within said aperture, said locking tongue being interlockable with said outer rose when said locking spindle is moved from an unlocked state to a locked state;
• a locking plate fixedly sleeved around said locking spindle in proximity to said locking tongue, said locking plate having a locking part extending radially to said inner surface of said surrounding wall;
• an inner handle having a push button that is connected to another end of said locking spindle, said push button being operable to press and move axially said locking spindle from said unlocked state to said locked state;
• and
• a biasing spring to bias said locking spindle to move to said unlocked state when said protrusion is moved away from said locking part;
• wherein, when said locking spindle is moved to said locked state, said locking part of said locking plate engages said protrusion on said surrounding wall to thereby prevent said locking spindle from returning to said unlocked state from said locked state;
• wherein said protrusion is movable away from said locking part of said locking plate to permit said locking spindle to return to said unlocked state when said latch operating tube is rotated relative to said locking spindle and said locking plate;
• wherein said protrusion is proximate to an annular free end of said surrounding wall, said enlarged end portion further having a notch that is indented from said annular free end of said surrounding wall and that is spaced angularly from said protrusion, said locking tongue being located outwardly of said annular free end and interlocking with said outer rose when said locking part of said locking plate engages said protrusion, said locking tongue being moved into said notch by said biasing spring when said latch operating tube is rotated to move said protrusion away from said locking part;
• and
• wherein said notch includes a shallow notch portion proximate to said annular free end, and a deep notch portion that is indented form a bottom of said shallow notch portion, said locking tongue being received in said deep notch portion when said locking spindle is in said unlocked state.

A cylinder lock assembly comprising:

• an outer rose;
• an outer handle;
• an outer drive tube disposed rotatably within said outer rose and connected to said outer handle, said outer drive tube having an axially elongated aperture;
• a latch operating tube connected to a latch unit, and having an enlarged end portion that extends into said outer drive tube opposite to said outer handle, said enlarged end portion having a surrounding wall, and a protrusion projecting inwardly and radially from an inner surface of said surrounding wall;
• a locking spindle extending movably in said latch operating tube and having one end that is inserted into said surrounding wall and that has a locking tongue extending radially and outwardly through said aperture of said outer drive tube and movable axially within said aperture, said locking tongue being interlockable with said outer rose when said locking spindle is moved from an unlocked state to a locked state;
• a locking plate fixedly sleeved around said locking spindle in proximity to said locking tongue, said locking plate having a locking part extending radially to said inner surface of said surrounding wall;
• and
• an inner handle having a push button that is connected to another end of said locking spindle, said push button being operable to press and move axially said locking spindle from said unlocked state to said locked state;
• wherein, when said locking spindle is moved to said locked state, said locking part of said locking plate engages said protrusion on said surrounding wall to thereby prevent said locking spindle from returning to said unlocked state from said locked state;
• wherein said protrusion is movable away from said locking part of said locking plate to permit said locking spindle to return to said unlocked state when said latch operating tube is rotated relative to said locking spindle and said locking plate;
• and
• wherein said protrusion is substantially wedge-shaped and has an inclined surface, said locking part contacting resiliently and slidingly said inner surface of said surrounding wall and being slidable over said inclined surface to come into engagement with said protrusion when said locking spindle moves to said locked state.