The invention relates to a novel expansion device 10 for drum brakes, which is floatingly and approximately centrally arranged between two substantially symmetrical brake shoes 3,4, the expansion device 10 comprising at least two gear levers articulated to each other and each supported on a brake shoe 3,4, at least one of the gear levers of the expansion lock 10 being coupled to an actuating element 9 of an actuator system 7 such that the brake shoes 3,4 carry out an even, translationally directed expanding movement (B), which is converted by a gearing, in the direction of the brake drum 11. The aim of the invention is to devise an efficient, improved drum brake module which is easy to maintenance and inexpensive and yet can be variably adapted to many applications and characteristics of modern electric motor driven wheel brake actuators. For this purpose, at least one of the gear levers of the spreader lock has a spring element 17 integrated into it that can be elastically reversibly deformed by a brake application force about a defined elasticity ΔS of at least 1 mm in a defined manner.