Patent ID: 8636781

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, the head receiving portion having an open end and being flexible so as to allow introduction and clamping of the head, the head receiving portion having an exterior surface with a tapered portion, wherein a longitudinal axis of the receiving part body extends from the rod receiving portion to the head receiving portion; and a locking ring configured to be arranged around the head receiving portion, the locking ring comprising an interior surface with a curved portion, wherein when the locking ring is around the head receiving portion, the curved portion 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 and is configured to engage the tapered portion of the exterior surface of the head receiving portion to clamp the head, such that when the head is clamped, the tapered portion has a profile different from the curved profile at the engagement with the curved portion.