The invention discloses a mechanical torque converter (100) having a casing (6), an input shaft (2) entering casing (6) and rotatable within the casing (6). An output shaft (5) exits casing (6) and is rotatable within casing (6). A gearbox (1) is located within casing (6) and coupled to input shaft (2). An escapement device (3) is within casing (6) and coupled to gearbox (1) to brake gearbox (1) under low speed and a clutch (4) co-operates with output shaft (5) and gearbox (1).