Patent ID: 8636782

Claim:
A receiving part for receiving a rod for coupling the rod to a bone anchoring element, the receiving part comprising: a receiving part body comprising: a rod receiving portion with a channel for receiving a rod, and a head receiving portion for accommodating a head of a bone anchoring element, wherein a longitudinal axis extends from the rod receiving portion to the head receiving portion, the head receiving portion having an open end and being flexible for inserting and clamping of the head, and an exterior surface with a curved portion having a convexly curved profile along a direction of the longitudinal axis; and a locking ring configured to be arranged around the head receiving portion, wherein the locking ring has an interior surface with a curved portion, such that when the locking ring is around the head receiving portion, the curved portion of the locking ring has a curved profile with a first section increasing in diameter and a second section decreasing in diameter along a direction parallel to the longitudinal axis for engagement with the curved portion of the exterior surface of the head receiving portion for locking a position of the head relative to the head receiving portion.