Patent ID: 8915337

Claim:
A brake device comprising: a damper which applies a braking force to a braking target by advancing towards and contacting the braking target; an advancing and retreating member which causes the damper to advance and retreat in a braking direction towards the braking target; a casing which supports the advancing and retreating member such that the advancing and retreating member is movable for advancing and retreating in the braking direction; and a gap adjustment mechanism which adjusts an initial position of the damper and the advancing and retreating member; wherein the gap adjustment mechanism comprises: a control section rotatably mounted to the casing via a shaft and having a control surface facing an opposite side to the braking side in the braking direction, an operation member which is formed in a circular shape and is capable of advancing and retreating in the braking direction together with the advancing and retreating member, and whose movement is controlled by contacting the control surface with an outer peripheral surface of the operation member as the advancing and retreating member advances towards the braking side in the braking direction, thereby enabling relative movement with respect to the advancing and retreating member towards the opposite side to the braking side in the braking direction, and a position adjustment section which, when the advancing and retreating member advances towards the braking side in the braking direction by a predetermined advance amount or more and the operation member relatively moves by a predetermined amount with respect to the advancing and retreating member, changes the initial position of the advancing and retreating member according to the relative movement amount of the operation member; wherein the position adjustment section comprises a sleeve which is axially rotatable about an axis extending in the braking direction and whose inner peripheral surface is threadably engaged with the advancing and retreating member, a ratchet gear which is axially rotatable about the axis extending in the braking direction together with the sleeve, a lever member which is rotatable with movement of the operation member, about a fulcrum that advances and retracts in the braking direction together with the advancing and retreating member, wherein the operation member is provided at a distal end of the lever member, and a pawl arranged to be movable for advancing and retracting in a predetermined direction according to the rotation of the lever member, and which turns the ratchet gear by moving towards an application side in a predetermined direction while engaged with the ratchet gear; wherein the control section is formed in a polygonal column shape, and an outer periphery of the polygonal column shape includes a plurality of peripheral surfaces; and wherein the peripheral surfaces of the polygonal column shape are formed at different distances, respectively, from the shaft of the control section.