Mechanical actuation device for drum brake

A drum brake including a carrier plate on which there are slidably mounted first and second shoes each one including a web and a rim section of which the face opposite the drum receives a friction lining capable of being brought into frictional engagement against an internal face of the drum by a hydraulic actuation device acting on a first end of said webs of said first and second shoes, a variable-length strut which in interaction with a tension spring, determines the se of said first and second shoes and which is located in the of said hydraulic actuation device a second end on said first and second webs of the shoes bearing, when the drum brake is at rest or hydraulically actuated, on a bearing piece integral with said carrier plate, said drum brake further comprising a mechanical actuation device for bringing said friction linings into frictional engagement against said internal face of said drum and said first and second webs on said shoes away from said bearing piece by means of a force-transmission device mounted on the web of said first shoe and bearing, when the drum brake is mechanically actuated, on the web of said second shoe by means of said variable-length strut and means for joining the two shoes together, characterized in that a brace is located on said web of said first shoe that includes an active part interposed retractably between said first end of said web of said first shoe and a first end of said force-transmission device.