Patent ID: 9132301
Filing Date: 2015-09-15
Classification: A62B,F16D

Abstract:
1. A speed responsive engagement device comprising: a wheel configured to rotate about a first axis, the wheel having a plurality of outwardly projecting spaced apart teeth forming pairs of adjacent teeth, wherein each tooth of each of the pairs of adjacent teeth are separated by a circumferential surface of the wheel respectively, each said circumferential surface having a length extending between each said tooth respectively, each point along each said length collectively defining a single circle which has a constant radius from a center of the wheel; a pawl configured to pivot about a second axis between a first unengaged position and a second engaged position, the second engaged position being when the pawl is in direct contact with one of the circumferential surfaces of the wheel; and a resilient element configured to urge said pawl towards the first unengaged position, the first unengaged position being when the pawl is not in contact with one of the circumferential surfaces of the wheel; the speed responsive engagement device configured such that when the wheel rotates in a first direction about said first axis at a speed of rotation below a predetermined threshold value, each tooth contacts the pawl in turn to pivot the pawl from the first unengaged position towards the second engaged position, generating an oscillating movement of the pawl about the second axis with an amplitude dependent on the speed of rotation of the wheel, so that as a direct result of the speed of rotation of the wheel reaching the predetermined threshold value, the amplitude from the oscillating movement becomes large enough to cause the pawl to move into the second engaged position and engage one of said teeth to prevent further rotation of the wheel in said first direction; wherein the resilient element is configured not to urge said pawl towards the first unengaged position when said pawl is in the second engaged position so that the pawl stays in the second engaged position for a threshold amount of distance upon counter rotation of the wheel in a second direction opposite of the first direction, each said length respectively defines the threshold amount of distance.