Watch Chiming Mechanism Catapult Spring Stop
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Solution Overview
Problem
Existing watch striking mechanisms suffer from significant kinetic energy loss and rebound issues when the hammer strikes the gong, leading to reduced acoustic levels and increased complexity in production.
Innovation Solution
Incorporating a stop on the path of the hammer drive spring to generate a catapult effect, allowing the hammer to strike the gong with increased speed and reduced energy loss, while maintaining the damping counter-spring's operation without adjustment, thus enhancing the acoustic level and preventing rebounds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a damping counter-spring is used to hold the hammer away from the gong, then the hammer can be controlled in its resting position, but significant kinetic energy is lost when the hammer strikes the gong, reducing acoustic level
Solution Approach 1:
The hammer assembly is segmented into multiple components: the hammer itself, a hammer arm, and a hammer support lever. This segmentation allows the damping counter-spring to act on the hammer support lever rather than directly on the hammer, isolating the energy loss mechanism from the striking action and improving kinetic energy efficiency while maintaining control.
2Loss of energy
If the pre-winding of the drive spring is increased to improve acoustic level, then the striking force increases, but the counter-spring must be adjusted via eccentric mechanism to prevent rebound, increasing complexity
Solution Approach 1:
The adjustment function is extracted from the hammer striking mechanism and placed in the independent timepiece adjustment mechanism. This allows pre-winding of the drive spring to be increased for higher acoustic level without requiring complex eccentric adjustments of the counter-spring, as the timepiece adjustment mechanism independently controls the triggering timing.
Solution Approach 2:
The timepiece adjustment mechanism serves multiple functions: it adjusts the triggering time of the hammer strike and independently controls the pre-winding of the drive spring. This multi-functionality eliminates the need for separate eccentric adjustments when changing pre-winding levels, reducing device complexity while maintaining acoustic performance.
3Loss of energy
If a complex hammer arrangement with hinged parts and elastic elements is used to reduce energy loss, then kinetic energy efficiency improves, but the design complexity of the striking mechanism increases
Solution Approach 1:
The damping function and hammer support function are merged into a single hammer support lever component. The damping counter-spring acts on this lever to provide both support and damping in one integrated structure, reducing energy loss without requiring separate hinged parts and elastic elements, thereby simplifying the overall hammer design.
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
The solution effectively increases the acoustic level produced by the gong while minimizing energy loss and rebound, allowing for greater pre-winding of the drive spring without adapting the counter-spring, thus improving the striking mechanism's efficiency and safety.
Implementation Method 1
A drive spring for the hammer of the mechanism may be configured as a beam or elastic leaf. This drive spring may be wound to drive the hammer against the gong
Implementation Method 2
The hammer is held at a distance from the gong by a damping counter-spring in its resting position. The damping counter-springs also slow the fall of each hammer before it strikes its respective gong and then return it to its rest position
Implementation Method 3
The sound produced by the gong being struck by the hammer is typically within the audible frequency range of 1 kHz to 20 kHz
Data Source
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AI summary
The mechanism (1) has a gong (21) connected to a gong-carrier (22), and a hammer (2) mounted on a plate for striking the gong at predetermined times. A damping counterspring (5) i.e. lever, maintains the hammer at a distance from the gong in an idle mode. A spring (3) is in the form of a beam or a strip spring and is wound to drive the hammer against the gong in strike mode to produce an acoustic sound. A stop member (10) is provided on path of the spring in the direction of the gong for increasing the strike speed following contact of a part of the spring in action against the stop member.