Chain lock

1. A chain lock, comprising:

a lock body having a combination lock core and a socket, wherein the combination lock core has a plurality of discs;

a linkage chain formed via linking a plurality of link plates and having a first end portion and a second end portion, wherein the first end portion is joined with the lock body, wherein the second end portion can be inserted into and secured to the socket, wherein the second end portion has a positioning hole, wherein the combination lock core locks the second end portion when the second end portion has been inserted into the socket, wherein the socket is disposed on a side face of the lock body, wherein the plurality of discs are exposed on the side face in a position other than the socket, wherein the linkage chain can be wound around the lock body when the second end portion is unlocked;

a latch having a latch first end and a latch second end opposite the latch first end; and

a cap attached to the latch second end, wherein the latch second end extends out of a first end of the lock body to join with the cap, wherein the second end portion of the linkage chain is secured by the latch first end when inserted into the socket with the cap in a lock position near the first end of the lock body as well as the latch first end passing through the positioning hole, wherein the second end portion of the linkage chain is able to leave the socket when the cap is in an unlock position and physically separated from the outermost top portion of the lock body as well as the latch first end not entering into the socket.

2. The chain lock of claim 1 wherein the second end portion has a positioning hole, wherein after the second end portion has been inserted into the socket, the latch first end is operable to pass through the positioning hole to prevent the second end portion from leaving the socket.

3. The chain lock of claim 1 , wherein the latch is movable along a pivot direction of the lock body when the combination lock core is in an unlock state, wherein the movement of the latch in the lock body is restricted when the combination lock core is in a lock state.

4. The chain lock of claim 1 , wherein the lock body further has an elastic unit disposed between the cap and the first end.

5. The chain lock of claim 1 , wherein the link plates are pivotally linked.

6. The chain lock of claim 5 , wherein the link plates are pivotally linked one over one.

7. The chain lock of claim 1 , wherein the lock body and the second end portion respectively have a positioning block and a positioning hole, wherein the positioning block engages with the positioning hole when the linkage chain has been wound around the lock body.

8. A chain lock, comprising:

a lock body having a combination lock core and a socket, wherein the combination lock core has a plurality of discs;

a linkage chain formed via linking a plurality of link plates and having a first end portion and a second end portion, wherein the first end portion is joined with the lock body, wherein the second end portion can be inserted into and secured to the socket, wherein the second end portion has a positioning hole, wherein the combination lock core locks the second end portion when the second end portion has been inserted into the socket, wherein the plurality of discs are exposed on the side face in a position other than the socket, wherein the linkage chain can be wound around the lock body when the second end portion is unlocked;

a latch having a latch first end and a latch second end opposite the latch first end;

a cap attached to the latch second end, wherein the latch second end extends out of a first end of the lock body to join with the cap, wherein the second end portion of the linkage chain is secured by the latch first end when inserted into the socket with the cap in a lock position near the first end of the lock body as well as the latch first end passing through the positioning hole, wherein the second end portion of the linkage chain is able to leave the socket when the cap is in an unlock position and physically separated from the outermost top portion of the lock body as well as the latch first end not entering into the socket; and

an elastic unit disposed between the cap and the first end, the elastic unit disposed surrounding the latch.

9. The chain lock of claim 8 , wherein the second end portion has a positioning hole, wherein after the second end portion has been inserted into the socket, the latch first end is operable to pass through the positioning hole to prevent the second end portion from leaving the socket.

10. The chain lock of claim 8 , wherein the latch is movable along a pivot direction of the lock body when the combination lock core is in an unlock state, wherein the movement of the latch in the lock body is restricted when the combination lock core is in a lock state.