| 摘要 |
The automatic adjustment of a drum brake, when the wear of the friction linings carried by the shoes justifies it, is obtained by way of an adjusting lever (30) mounted pivotally on one (12a) of the shoes and carrying a toothed quadrant (30a), on which a pawl (34) is normally engaged. A spacer connecting the ends of the shoes between which the brake motor is located interacts with the adjusting lever by way of a connection with play. To prevent inopportune adjustment as a result of heating of the drum, a blocking member (52) carried by a metallic strip (50) fastened to the pivot pin (36) of the pawl (34)immobilizes the latter in terms of rotation when the temperature exceeds a certain threshold, thus increasing the functional play.
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