Impingement cooling of a blade platform

A turbomachine component, comprising:

• an aerofoil having a pressure side and a suction side, wherein the pressure side and the suction side meet at a trailing edge and a leading edge;
• a first platform comprising an aerofoil side wherefrom the aerofoil extends radially, an opposite side of the aerofoil side, and a first-platform cavity positioned in a first overhang region of the first platform, wherein the first-platform cavity extends within the first platform and comprises an aerofoil-side cavity wall along the aerofoil side, and
• a plurality of impingement plates arranged successively along an axial direction within the first-platform cavity, wherein each of the impingement plates comprises:
• an aerofoil-side part extending towards and connected to the aerofoil-side cavity wall of the first-platform cavity;
• a flow-input-side part extending towards a direction opposite to the aerofoil-side cavity wall of the first-platform cavity;
• and
• a central plate between the aerofoil-side part and the flow-input-side part;
• wherein the central plate is suspended by the aerofoil-side part and the flow-input-side part in the first-platform cavity extending along the aerofoil-side cavity wall such that the impingement plate defines, within the first-platform cavity in a radial direction, an aerofoil-side segment and a flow-input-side segment corresponding to said impingement plate and wherein the central plate comprises impingement holes such that cooling air entering the first-platform cavity is adapted to flow within the first-platform cavity from the flow-input-side segment of one impingement plate through the impingement holes to the aerofoil-side segment of said impingement plate and therefrom to the flow-input-side segment of a following impingement plate.