Latch-bolt mechanism operable to allow for idle rotation of an exterior handle

1. A latch-bolt mechanism comprising:

a housing;

a latch-bolt movable relative to said housing between an extended position and a retracted position and including a bolt body that is disposed movably on said housing, an engaging member that is operable to move on said bolt body between an engagement position and a disengagement position and that has an engaging portion, and a coupling device that connects said bolt body to said engagement member; and

a driving device including a first drive member disposed in said housing and having a first driving portion, said first driving portion of said first drive member being activated to contact and push said engaging portion of said engaging member so as to move said latch-bolt from the extended position to the retracted position when said engaging member is disposed at the engagement position, contact between said first driving portion of said first drive member and said engaging portion of said engaging member being prevented when said engaging member is disposed at the disengagement position;

wherein:

said bolt body includes a plate body disposed in said housing;

said coupling device includes first, second, and third coupling members, and a pushing member that is disposed movably on said plate body, that is in contact with said engaging member, and that is activatable to allow for movement of said engaging member between the engagement position and the disengagement position, said pushing member cooperating with said first, second, and third coupling members to connect said bolt body to said engagement member, said second coupling member being formed with a slot, said pushing member being disposed on said slot of said second coupling member; and

wherein said driving device further includes:

a first mounting member disposed in said housing and permitting said first drive member to be disposed thereon;

a second mounting member disposed in said housing;

a second drive member disposed between said first and second mounting members such that said first mounting member is disposed between said first and second drive members;

a third drive member disposed on said second mounting member such that said second mounting member is disposed between said second and third drive members;

a first driving rod extending through either said first or third drive member for driving synchronous rotation of said first and third drive members; and

a second driving rod extending through said second drive member for driving rotation of said second drive member.

2. The latch-bolt mechanism as claimed in claim 1 , wherein said coupling device of said latch-bolt further includes a resilient member for biasing said engaging member to contact said pushing member.

3. The latch-bolt mechanism as claimed in claim 2 , wherein said pushing member has a first portion and a second portion, said engaging member having a contacting portion biased by said resilient member to move into contact with said first portion of said pushing member when said engaging member is disposed at the engagement position and with said second portion of said pushing member when said engaging member is disposed at the disengagement position, said latch-bolt mechanism further comprising a pushbutton device that is in operational contact with said pushing member between a first pushing position, making said first portion to be aligned with said engagement member to allow movement of said latch-bolt, and a second pushing position, moving said pushing member to allow said second portion to be aligned with said engagement member, preventing movement of said latch-bolt.

4. The latch-bolt mechanism as claimed in claim 3 , wherein said pushbutton device includes:

a pushing plate disposed pivotally in said housing;

a first pushbutton rod disposed movably in said housing and operable to rotate said pushing plate in a first rotational direction;

a second pushbutton rod disposed movably in said housing and operable to rotate said pushing plate in a second rotational direction opposite to the first rotational direction;

a movable plate disposed movably in said housing, said movable plate being driven by said pushing plate to move in a first horizontal direction when said pushing plate is rotated in the first rotational direction, said movable plate being driven by said pushing plate to move in a second horizontal direction when said pushing plate is rotated in the second rotational direction; and

a crank plate disposed pivotally in said housing and having a pushing portion biased toward said pushing member of said latch-bolt, said pushing portion of said crank plate being rotated by said movable plate away from said pushing member of said latch-bolt such that said first portion of said pushing member is biased to contact said contacting portion of said engaging member when said movable plate is moved in the first horizontal direction, said pushing portion of said crank plate being biased to rotate to thereby contact and move said pushing member of said latch-bolt such that said second portion of said pushing member comes into contact with said contacting portion of said engaging member when said movable plate is moved in the second horizontal direction.

5. The latch-bolt mechanism as claimed in claim 4 , wherein said pushbutton device further includes a torsion spring for biasing said pushing portion of said crank plate to contact and move said pushing member of said latch-bolt such that said second portion of said pushing member comes into contact with said contacting portion of said engaging member when said movable plate is moved in the second horizontal direction.

6. The latch-bolt mechanism as claimed in claim 1 , wherein said latch-bolt further includes a driven portion, and said second drive member of said driving device has a second driving portion that is rotatable in said housing to contact and push said driven portion to thereby move said latch-bolt from the extended position to the retracted position.

7. The latch-bolt mechanism as claimed in claim 6 , wherein said latch-bolt includes:

a connecting member having an insert portion, said insert portion having an annular outer surface formed with an annular groove;

a bolt head having a sleeve portion that is sleeved rotatably on said insert portion of said connecting member and that is formed with an axially extending central hole permitting said insert portion of said connecting member to be disposed rotatably therein, and a radially extending pinhole in spatial communication with said central hole; and

a pin extending through said pinhole in said bolt head and into said annular groove in said connecting member so as to prevent axial movement of said bolt head relative to said connecting member.

8. The latch-bolt mechanism as claimed in claim 1 , wherein said latch-bolt includes:

a connecting member having an insert portion, said insert portion having an annular outer surface formed with an annular groove;

a bolt head having a sleeve portion that is sleeved rotatably on said insert portion of said connecting member and that is formed with an axially extending central hole permitting said insert portion of said connecting member to be disposed rotatably therein, and an opening in spatial communication with said central hole; and

a retaining ring extending through said opening in said bolt head and into said annular groove in said connecting member so as to prevent axial movement of said bolt head relative to said connecting member.

9. A latch-bolt mechanism comprising:

a housing;

a latch-bolt movable relative to said housing between an extended position and a retracted position and including a bolt body that is disposed movably on said housing, an engaging member that is operable to move on said bolt body between an engagement position and a disengagement position and that has an engaging portion, and a coupling device connecting said bolt body to said engagement member and including first, second, and third coupling members, and a pushing member having a first portion and a second portion, said pushing member being movable on said bolt body such that said engaging member is moved into contact with said first portion of said pushing member when said engaging member is disposed at the engagement position and with said second portion of said pushing member when said engaging member is disposed at the disengagement position, said pushing member cooperating with said first, second, and third coupling members to connect said bolt body to said engagement member, said second coupling member being formed with a slot, said pushing member being disposed on said slot of said second coupling member;

a pushbutton device that is in operational contact with said pushing member between a first pushing position, making said first portion to be aligned with said engagement member to allow movement of said latch-bolt, and a second pushing position, moving said pushing member to allow said second portion to be aligned with said engagement member, preventing movement of said latch-bolt; and

a driving device including a first drive member disposed in said housing and having a first driving portion, said first driving portion of said first drive member being activated to contact and push said engaging portion of said engaging member so as to move said latch-bolt from the extended position to the retracted position when said engaging member is disposed at the engagement position, contact between said first driving portion of said first drive member and said engaging portion of said engaging member being prevented when said engaging member is disposed at the disengagement position;

wherein said driving device further includes:

a first mounting member disposed in said housing and permitting said first drive member to be disposed thereon;

a second mounting member disposed in said housing;

a second drive member disposed between said first and second mounting members such that said first mounting member is disposed between said first and second drive members;

a third drive member disposed on said second mounting member such that said second mounting member is disposed between said second and third drive members;

a first driving rod extending through either said first or third drive member for driving synchronous rotation of said first and third drive members; and

a second driving rod extending through said second drive member for driving rotation of said second drive member.

10. A latch-bolt mechanism comprising:

a housing;

a latch-bolt movable relative to said housing between an extended position and a retracted position and including a bolt body that is disposed movably on said housing, an engaging member that is operable to move on said bolt body between an engagement position and a disengagement position and that has an engaging portion, and a coupling device connecting said bolt body to said engagement member and including first, second, and third coupling members, and a pushing member movable on said bolt body, and a resilient member for biasing said engaging member to move into contact with said pushing member such that movement of said pushing member on said bolt body results in movement of said engaging member between the engagement position and the disengagement position; said pushing member having a first potion and a second portion and cooperating with said first, second, and third coupling members to connect said bolt body to said engagement member, said second coupling member being formed with a slot, said pushing member being disposed on said slot of said second coupling member;

a pushbutton device that is in operational contact with said pushing member between a first pushing position, making said first portion to be aligned with said engagement member to allow movement of said latch-bolt, and a second pushing position, moving said pushing member to allow said second portion to be aligned with said engagement member, preventing movement of said latch-bolt; and

a driving device including a first drive member disposed in said housing and having a first driving portion, said first driving portion of said first drive member being activated to contact and push said engaging portion of said engaging member so as to move said latch-bolt from the extended position to the retracted position when said engaging member is disposed at the engagement position, contact between said first driving portion of said first drive member and said engaging portion of said engaging member being prevented when said engaging member is disposed at the disengagement position;

wherein said driving device further includes:

a first mounting member disposed in said housing and permitting said first drive member to be disposed thereon;

a second mounting member disposed in said housing;

a second drive member disposed between said first and second mounting members such that said first mounting member is disposed between said first and second drive members;

a third drive member disposed on said second mounting member such that said second mounting member is disposed between said second and third drive members;

a first driving rod extending through either said first or third drive member for driving synchronous rotation of said first and third drive members; and

a second driving rod extending through said second drive member for driving rotation of said second drive member.