A joint lock having a lock body that accommodates a combination locking mechanism and having a jointed bar hoop that has a plurality of jointed bars pivotably connected to one another and a locking bar, wherein a first end of the jointed bar hoop is permanently fastened to the lock body and a second end of the jointed bar hoop has the locking bar; wherein the combination locking mechanism has a plurality of code rings rotatable about an axis of rotation and a latch which is preloaded along the axis of rotation in the direction of a locked position, wherein the latch is movable in the direction of a release position when a secret code is set at the code rings, and wherein the latch is blocked in the locked position when the secret code is not set at the code rings; wherein the lock body has an introduction opening through which the locking bar of the jointed bar hoop can be introduced into the lock body along an introduction direction which is oriented transversely to the axis of rotation of the code rings, with the locking bar introduced into the lock body being locked to the lock body when the latch is in the locked position and is blocked, characterized in that the latch and/or the locking bar has/have at least one slope (29, 31, 33, 35) that is configured to effect an urging back of the preloaded latch from the locked position into the release position on a removal of the locking bar from the introduction opening of the lock body and/or on an introduction of the locking bar into the introduction opening of the lock body, wherein the combination locking mechanism is held in a holder, wherein the holder has an abutment which is configured to bound a movement of the latch effected by the preload of the latch in the direction of the locked position, wherein the lock body has a housing in which the holder for the combination locking mechanism is received. wherein the combination locking mechanism has a plurality of code rings rotatable about an axis of rotation and a latch which is preloaded along the axis of rotation in the direction of a locked position, wherein the latch is movable in the direction of a release position when a secret code is set at the code rings, and wherein the latch is blocked in the locked position when the secret code is not set at the code rings; wherein the lock body has an introduction opening through which the locking bar of the jointed bar hoop can be introduced into the lock body along an introduction direction which is oriented transversely to the axis of rotation of the code rings, with the locking bar introduced into the lock body being locked to the lock body when the latch is in the locked position and is blocked, characterized in that the latch and/or the locking bar has/have at least one slope (29, 31, 33, 35) that is configured to effect an urging back of the preloaded latch from the locked position into the release position on a removal of the locking bar from the introduction opening of the lock body and/or on an introduction of the locking bar into the introduction opening of the lock body, wherein the combination locking mechanism is held in a holder, wherein the holder has an abutment which is configured to bound a movement of the latch effected by the preload of the latch in the direction of the locked position, wherein the lock body has a housing in which the holder for the combination locking mechanism is received.