Retrograde Horological Display Mechanism with Disconnection Lever
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Solution Overview
Problem
Retrograde horological display mechanisms, particularly of the dragging type, often provide incorrect indications during the retrograde return to the starting position, leading to a perception of design defects or malfunctions in high-value timepieces.
Innovation Solution
A dragging type retrograde horological display mechanism equipped with a disconnection device, featuring a display wheel, display pinion, fixed display wheel, pivoting holding element, and a display disconnection lever with an elastic strip, allowing accurate indication by relaxing tension and enabling smooth retrograde return to the initial position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dragging type retrograde horological display mechanism is used to display date indications, then the mechanism can successfully transition from one date to the next, but during the retrograde return to the starting point, the display hand exceeds the last indication and provides incorrect information for several hours
Solution Approach 1:
The patent extracts the display hand from the driving mechanism during the retrograde return phase. The display hand is disconnected from the date-changing mechanism when the mechanism returns from the end position to the starting point, preventing it from indicating incorrect dates during this period. This is achieved through a disconnection device that separates the display hand's movement from the internal mechanism's retrograde motion.
Solution Approach 2:
The patent segments the operation of the retrograde mechanism into distinct phases: the forward counting phase where the display hand normally operates, and the retrograde return phase where the display hand is disconnected. This segmentation allows the mechanism to maintain accurate display during the forward phase while avoiding incorrect indications during the return phase.
2Device complexity
If the display hand is kept connected to the mechanism during retrograde return, then the mechanism structure remains simple, but the display hand provides incorrect indications for several hours
Solution Approach 1:
The patent introduces a disconnection device as an intermediary between the retrograde mechanism and the display hand. This intermediary component selectively engages or disengages the display hand from the mechanism based on the operational phase, allowing the system to maintain both structural simplicity and display accuracy.
3Reliability
If the display hand is disconnected during retrograde return, then accurate display is maintained, but the mechanism complexity increases due to additional disconnection components
Solution Approach 1:
The patent merges the disconnection function with existing components of the retrograde mechanism. The disconnection device is integrated into the mechanical structure, utilizing the same spatial and functional resources already present in the mechanism, thereby minimizing the increase in overall complexity while achieving the desired display accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Ensures continuous accurate display during the retrograde return, preventing incorrect indications and enhancing the perception of the timepiece's reliability and quality.
Implementation Method 1
a display disconnection lever rigidly connected to the display pinion and coupled in rotation with the display wheel, this display disconnection lever comprising an elastic strip against which the holding element is disposed
Data Source
AI summary
A dragging type retrograde horological display mechanism, arranged to successively display first and distinct indications in a retrograde manner, including a display wheel driven by a drive wheel; a pivoting holding element engaged in a toothing of a fixed display wheel; a return element that constrains a display pinion in rotation; a display disconnection lever including an elastic strip; when the retrograde horological display mechanism moves from the display of the last indication to the display of the next first indication, the holding element pivots, whereas the display disconnection lever is locked, such that the elastic strip becomes strained and the holding element is forced to be released from the toothing of the fixed display wheel, thus enabling the stress induced by the return element to relax and return the retrograde horological display mechanism in the retrograde direction in the initial position to display the first indication.