Rotational friction brake regulated by angular acceleration

A rotational friction brake actuated and regulated by the rate of change of the angular speed, comprising:

• a first body,
• a second body rotationally attached to said first body, said second body being arranged to rotate around a rotational center axis of said second body,
• at least one braking arm rotationally attached to said second body in a pivot point wherein
• said pivot point is eccentrically offset to said rotational center axis along a radial axis,
• said at least one braking arm comprises a braking member arranged to frictionally engage a part of said first body,
• said at least one braking arm having a mass center placed along a braking arm axis,
• said braking arm axis
• intersecting said pivot point,
• forming an angle α to a normal axis, said normal axis being defined perpendicular to said radial axis through said pivot point,
• wherein said mass center is placed at a distance from said pivot point that is longer than
• a distance from said pivot point to said rotational center axis, wherein
• said braking member is arranged to frictionally engage said part of said first body for values of α larger than a first angle α1, and
• at least one stop member, wherein each of the at least one stop member is arranged to limit the movement of each of the at least one braking arm such that the angle α is limited to a minimum angle larger than a second angle α2, at which angle each of the at least one braking arm is in a non-braking position, thus limiting movement of said at least one braking arm relative to said second body,
• wherein said first angle α1 is larger than said second angle α2,
• wherein said second angle α2 is within the range 80°<a2<100°, such that the at least one braking arm reacts on said rate of change of the angular speed, thereby moving in relation to said second body to actuate the rotational friction brake.