Coupling assembly configured to be used in a personal care appliance at an interface between a body and a head of the personal care appliance for releasably coupling the body and the head, wherein the coupling assembly comprises a coupling element and a retaining member having a receiving space which is configured to receive and accommodate the coupling element, wherein one of the coupling element and the retaining member comprises at least one cam element (54, 55) projecting in a direction of a central axis of the coupling assembly and another of the coupling element and the retaining member comprises at least one notch (45, 46) which is configured to receive and accommodate the at least one cam element (54, 55) so as to constitute at least one coupling combination, wherein, in a peripheral direction about the central axis, the at least one cam element (54, 55) has two oppositely sloped surfaces (56, 57) converging in a direction from a base to a furthest projecting end of the at least one cam element (54, 55), and the at least one notch (45, 46) has two oppositely sloped surfaces (47, 48) converging in a direction from an open side to a deepest side of the at least one notch (45, 46) so as to allow release of a coupled position of the coupling assembly on the basis of a rotation of the coupling element and the retaining member with respect to each other about the central axis, characterized in that, in the at least one coupling combination, the cam element (54, 55) and the notch (45, 46) are configured to leave space between them at the position of a furthest projecting non-contact portion of the cam element (54, 55) and an associated deepest non-contact portion of the notch and to only contact each other at two sides through their sloped surfaces (47, 48; 56, 57) at the position of a less projecting contact portion of the cam element (54, 55) and an associated less deep contact portion of the notch (45, 46) in the coupled position of the coupling assembly. wherein the coupling assembly comprises a coupling element and a retaining member having a receiving space which is configured to receive and accommodate the coupling element, wherein one of the coupling element and the retaining member comprises at least one cam element (54, 55) projecting in a direction of a central axis of the coupling assembly and another of the coupling element and the retaining member comprises at least one notch (45, 46) which is configured to receive and accommodate the at least one cam element (54, 55) so as to constitute at least one coupling combination, wherein, in a peripheral direction about the central axis, the at least one cam element (54, 55) has two oppositely sloped surfaces (56, 57) converging in a direction from a base to a furthest projecting end of the at least one cam element (54, 55), and the at least one notch (45, 46) has two oppositely sloped surfaces (47, 48) converging in a direction from an open side to a deepest side of the at least one notch (45, 46) so as to allow release of a coupled position of the coupling assembly on the basis of a rotation of the coupling element and the retaining member with respect to each other about the central axis, characterized in that, in the at least one coupling combination, the cam element (54, 55) and the notch (45, 46) are configured to leave space between them at the position of a furthest projecting non-contact portion of the cam element (54, 55) and an associated deepest non-contact portion of the notch and to only contact each other at two sides through their sloped surfaces (47, 48; 56, 57) at the position of a less projecting contact portion of the cam element (54, 55) and an associated less deep contact portion of the notch (45, 46) in the coupled position of the coupling assembly.