Rotational friction brake actuated and regulated by angular acceleration and a fishing reel comprising the same

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

• a first body having a first friction surface,
• a second body rotationally attached to the first body, the second body being configured to rotate around a rotational center axis of the second body,
• an actuator arrangement configured to move a second friction surface into frictional engagement with the first friction surface, the second friction surface being configured to rotate together with the second body, the actuator arrangement comprising:
• an actuator arm being configured to rotate together with the second body and being pivotably attached to the second body in a pivot point, wherein the pivot point is eccentrically offset to the rotational center axis along a radial axis,
• wherein the actuator arrangement has a geometrical mass center, the pivot point and the geometrical mass center defining an actuator axis,
• wherein the actuator arrangement further has a radius of gyration relative to the pivot point as seen in the actuator arrangement's rotation together with the second body, the radius of gyration being longer than a distance between the pivot point and the rotational center axis,
• wherein the actuator axis intersects the pivot point, forming an angle to a normal axis, the normal axis being defined perpendicular to the radial axis through the pivot point, and
• wherein the second friction surface is arranged to frictionally engage with the first friction surface for values of the angle being equal to, or larger than, a first angle, and
• a stop member configured to limit the movement of the actuator arrangement relative to the second body, such that the angle is limited to a minimum angle larger than a second angle, at which angle the actuator arrangement is in a non-braking position,
• wherein the first angle is larger than the second angle, and wherein the second angle is within the range from 80° to 100°, and
• wherein the actuator arrangement has an internal flexibility which allows a shape of the actuator arrangement to depend on centrifugal forces acting thereon, said internal flexibility being configured such that:
• (a) the first angle depends on the angular speed of the rotating second body, and/or
• (b) the second angle depends on the angular speed of the rotating second body, and/or
• (c) a portion of the actuator arrangement, when being in the non-braking position, makes contact with a portion of the first and/or second bodies in response to the angular speed of the second body exceeding an angular speed threshold, thereby transmitting a force from said contact to the actuator arm so as to facilitate actuation of the brake,
• wherein the actuator arrangement is configured to move in relation to the second body from the non-braking position to a braking position at which the second friction surface comes into frictional engagement with the first friction surface so as to actuate the rotational friction brake.