Patent ID: 8215027

Claim:
A tape measure with a self-regulating speed control mechanism, comprising: a casing; a bobbin rotatably provided in the casing; a blade wound around the bobbin, the blade having a first end fastened to the bobbin and a second end exposed outside the casing, with graduations marked on the blade and arranged in a longitudinal direction thereof so as to measure lengths; a first elastic member providing rotating force to the bobbin so that the blade that has been extracted from the casing is returned to an original position thereof by the rotating force of the bobbin; a movable mounting plate provided on a sidewall of the bobbin so as to be movable in such a way that a distance of the movable mounting plate from a rotation center of the bobbin is changed, so that when the bobbin rotates around the rotation center, the movable mounting plate is rotated around the rotation center along with the bobbin and moved away from the rotation center of the bobbin by centrifugal force applied to the movable mounting plate; a second elastic member provided on the sidewall of the bobbin, the second elastic member elastically supporting the movable mounting plate towards the rotation center of the bobbin; a roller rotatably mounted to the movable mounting plate, the roller being made of rubber; a support ring protruding from the casing towards the sidewall of the bobbin on which the movable mounting plate is provided; an acceleration prevention member made of rubber, the acceleration prevention member being provided on an inner surface of the support ring and covering a portion of the inner surface of the support ring, so that when the bobbin rotates, the acceleration prevention member comes into contact with the roller to prevent a rotational speed of the bobbin from increasing, wherein when the bobbin rotates, the roller alternately comes into contact with the inner surface of the support ring and the acceleration prevention member.