Tape measure brake

In a tape rule or the like linear measuring instrument comprising a casing having an outlet slot for a measuring-tape wound on a winding drum, a tape return spring and a tape locking device which comprises a control button disposed in an opening in a front wall of the casing above the tape outlet slot and a brake block which in a locking position grips the tape against an inner bearing face of the casing, the improvement in which the tape locking device comprises first and second levers pivotally connected together about a pin to form an elbow-joint, the first lever forming the control button and being tippably mounted about a first pivot fixed with the casing and parallel to the axis of the winding drum, the second lever having an end opposite said pin forming said brake block and being tippably mounted and movable in translation in its longitudinal direction by engagement of an oblong hole in the second lever about a second pivot fixed with the casing and parallel to the first pivot, a line of junction connecting said first and second pivots being at least approximately perpendicular to said bearing face, said levers being able to tip between an unlocking position in which said pin is spaced apart on one side of said line of junction and the brake block is spaced apart from the tape, and said locking position defined by an abutment fixed with the casing and in which said pin is located on the other side of said line of junction, said brake block when in said locking position coacting with the tape to hold the first and second levers in the locking position which is thus made stable, and comprising means for releasably holding the first and second levers in the unlocking position.