Patent ID: 7139224

Claim:
A calendar stepping mechanism of an eternal calendar of a clock having a calendar date display, comprising: a stepped month disk having a periphery provided with twenty indentations of different depths and twenty elevations, said indentations and elevations representing the forty-eight months of a leap year period, said stepped month disk being drivable to rotate at a rate of one step per month and one revolution per four years; a stepping lever drivable once per twenty-four hours about a pivot axis between a normal position and a raised position; a probe finger arranged on the stepping lever which is in a position against the circumferential periphery of a stepped month disk in the normal position of the stepping lever and moves radially outward in response to the pivoting movement of said stepping lever toward the raised position; a rotatably supported calendar wheel having thirty-one teeth or a multiple thereof, wherein one of said teeth comprises a stepping tooth projecting radially beyond the other normal teeth and wherein the calendar date display is drivable by said calendar wheel; a stepping pawl hinged to said stepping lever and having a pawl tooth, wherein said pawl tooth engages radially in the gaps between the teeth of the calendar wheel and rotates said calendar wheel in response to the pivoting movement of the stepping lever, the extent of the pivoting movement of the stepping lever depending on the contact position of the probe finger on the periphery of the stepped month disk; and a connecting link arranged such that, during the pivoting movement of said stepping lever from its normal position into its raised position, the stepping pawl slides along the connecting link, wherein during a first part of the pivoting movement of said stepping lever, the connecting link supports the pawl tooth at a radial distance from an axis of said calendar wheel between the tip circle of the normal teeth and the tip circle of said stepping tooth and, during the second part of the pivoting movement of the shifting lever, the connecting link supports the pawl tooth at a radial distance inward of the tip circle of the normal teeth, wherein a transition from the first part to the second part of the pivoting movement of the stepping lever occurs at the point which the pawl tooth occupies when the stepping lever is in its normal position and the probe finger is in contact with one of the elevations of the stepped month disk.