Patent ID: 6106068
Filing Date: 2000-08-22
Classification: B60N

Abstract:
An automatic index guiding device (1) in combination with a movable part (2) pivotably mounted about a rotational axis (3) on a part (4) arranged to be stationary relative to the rotational axis (3), the movable part (2) being movable relative to the stationary part (4) between at least two distinct angular positions (P1, P2) delimiting at least two angular sectors (A1, A2), said at least two angular sectors (A1, A2) having a common limit (P3) and a common vertex located on the rotational axis (3), comprising:a) a primary sector (A1), in which movable part (2) is arranged to be displayed, at least in a first direction of displacement (S1) toward one of the angular positions (P1, P2) of said primary sector (A1), at least by an angular fraction of said primary sector (A1), but without the capability to return directly in a second, opposite direction (S2) to any previously abandoned position, due to said displacement in the first direction (S1),b) a secondary sector (A2) within which said movable part (2) can be moved freely,(c) a first ratchet (7A) including a notched ramp (7) in the form of a cylindrical case carried indirectly by one of the pivoting parts, and a second ratchet (6) having a toothed surface (6B) that cooperates with the notched ramp (7), said second ratchet (6) being carried by the other pivoting part, said second ratchet (6) being pivotly mounted about an axis (6A) substantially parallel to the rotational axis (3) of the stationary part (4) and movable part (2) wherein:i) when the movable part (2) and stationary part (4) are stressed so as to be angularly displaced in the second direction (S2), immobilization of the second ratchet (6) in a locked position with toothed surface (6B) against the ramp (7) of the first ratchet (7A) is obtained, andii) when the movable part (2) and the stationary part (4) are angularly stressed in the first direction (S1), an elastic disengagement of notches of the ramp (7) and the second ratchet (6) is obtained, and as a result of said elastic disengagement, adjustment of the angularly position of the movable part (2) and the stationary part (4) in the first direction (S1) occurs,d) said second ratchet (6) being arranged to pivot about said axis (6A) between various positions includingi) a fully engaged position (SA) in which the second ratchet (6) has a toothed surface (6B) pressed tightly against the notched ramp (7) of the first ratchet (7A),ii) an adjustment position (SR) in which the second ratchet (6) has pivoted on its axis (6A) and has only one remaining tooth (6C) of its toothed surface (6B) in contact with the notched ramp (7),iii) a fully spaced position (SE) in which the second ratchet (6) has pivoted on its axis (6A) past the adjustment position (SR) and no teeth of toothed surface (6B) are in contact with the notched ramp (7), and(e) said toothed surface (6B) of the second ratchet (6) being formed in an angular sector (6S) wherein the fully engaged position (SA) of the toothed surface (6B) is arranged to be operationally in the fully engaged position (SA) against the notched ramp (7) when the angular sector (6S) is centered on the rotational axis (3) of the movable part (2) and does not comprise the pivot axis (6A) of said second ratchet (6) and is disposed relative to an imaginary line passing through the rotational axis (3) and the pivot axis (6a) wherein:i) when the movable part (2) is stressed in the first direction of displacement (S1), and the second ratchet (6) is substantially in its fully engaged position (SA) against the ramp (7), the second ratchet (6) disengages from the fully engaged position (SA) against the ramp (7) and assumes adjustment position (SR), andii) when the movable part (2) is stressed in the second direction of displacement (S2) and the second ratchet (6) is in the adjustment position (SR), the second ratchet (6) disengages from the adjustment position (SR) and assumes its fully engaged position (SA) against the ramp, and further comprising an indexed disengaging mechanism having an operation indexed as a function of an angular position of movable ;part (2) and stationary part (4) and is arranged to cause the second ratchet (6) to have one of a first mode and second mode, wherein the first mode includes the second ratchet (6) being held in a spaced position apart from ramp (7), and the second mode includes the second ratchet (6) being released toward ramp (7), said disengaging mechanism being indexed by indexing stops (48, 481, 49, 491) disposed in a way that:a) when movable part (2) reaches an angular limit (P3) of the primary sector (A1) opposite a limit (P1) of sector (A1) from which the movable part (2) was able to be displaced incrementally in the first direction (S1), the second ratchet (6) is moved, at least indirectly by two opposing indexing stops (48, 481), into the fully spaced position (SE), then the second ratchet (6) is held in position (SE) by a first elastic holding means (44), for any position of the movable part (2) comprised within a quarternary angular sector (A4) constituted by the juxtaposition of the two primary (A1) and secondary (A2) sectors, with the exception of the extreme angular position (P1) of the primary angular sector (A1) from which indexed adjustment can be obtained, andb) when the movable part (2), firstly, is maneuvered in the second direction (S2) from a position (P2) of the secondary sector (A2) which is opposite position (P3) from which the second ratchet (6) has been brought into and held in the fully spaced position (SE), and secondly, reaches the position (P1) from which the second ratchet (6) must set the incremented adjustment, said second ratchet (6) is released, at least into the adjustment position (SR).