Patent ID: 6289860
Filing Date: 2001-09-18
Classification: F01L,Y10T

Abstract:
A centrifugally-actuated assembly for controlling the phase relationship between the crankshaft and at least one camshaft of an internal combustion engine, the assembly comprising:an outer ring member which is connectable to the crankshaft of an internal combustion engine for receiving rotating torque from the crankshaft;a hub which is connectable to at least one camshaft of the internal combustion engine for transmitting torque from the outer ring member to the camshaft so that the hub and camshaft rotate with the outer ring member about an axis of rotation, the hub being associated with the outer ring member in a manner which accommodates a rotational shift of the hub relative to the outer ring member about the axis of rotation between a first condition at which the hub is in one phase relationship with the outer ring member and a second condition at which the hub is in another phase relationship with the outer ring member, and the hub and outer ring member cooperate with one another so that a rotational shift of the hub relative to the outer ring member is guided along a predetermined path within the outer ring member;at least two centrifugally-responsive lever members wherein each lever member is pivotally connected to the outer ring member for pivotal movement of the lever member relative to the ring member between a first position at which the lever member is disposed in a first positional relationship with respect to the rotation axis and a second position at which the lever member is disposed in a second positional relationship with respect to the rotation axis, and each lever member is connected to the hub so that movement of the lever member between the first position and the second position effects a rotational shift of the hub relative to the outer ring member about the axis of rotation between the first condition and the second condition to thereby adjust the phase relationship between the crankshaft and the camshaft driven thereby;first biasing means interposed between the outer ring member and the lever members for biasing the lever members from the second position toward the first position in opposition to the centrifugal forces generated by the rotation of the hub about the axis of rotation wherein the biasing means includes leaf spring means which are adapted to act between the outer ring member and at least one lever member for biasing the at least one lever member from the second position toward the first position in opposition to the centrifugal forces generated by the rotation of the hub about the axis of rotation; anda second biasing means interposed between the outer ring member and the hub for biasing the hub from the second condition toward the first condition in opposition to the valve train torque exerted upon the hub through the camshaft, wherein the second biasing means includes at least one resilient spring which is interposed between the hub and the outer ring for continually biasing the hub from the second condition toward the first condition in opposition to the valve train torque exerted upon the hub through the camshaft.