Watch Movement Plate Wear Protection via Hardened Insert
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Watch mechanisms experience high wear due to friction between components made of copper alloy and harder materials like steel, leading to costly replacements, particularly affecting the movement plate.
Innovation Solution
A structural component with a protection device featuring a removable insert of higher surface hardness than the component, which is designed to reduce wear by interposing between the plate and the wheel set, providing a sliding surface and indexing features for precise positioning and rotation stop, allowing the structural component to maintain longevity without material changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the movement plate is made of copper alloy to reduce cost and weight, then manufacturing cost and weight are reduced, but wear resistance deteriorates due to friction with harder components like steel winding pinions
Solution Approach 1:
The patent applies a harder material treatment specifically to the contact surface of the movement plate where friction occurs with the winding pinion, while the rest of the plate maintains its original copper alloy composition. This localized hardening (through case hardening, nitriding, or applying a hard coating) provides wear resistance at the critical contact zone without changing the overall material properties, thus maintaining cost-effectiveness and weight advantages.
Solution Approach 2:
The patent creates a composite structure by combining copper alloy base material with a harder surface layer or coating. This composite approach allows the bulk material to remain inexpensive and lightweight while the surface layer provides enhanced wear resistance, effectively resolving the contradiction between cost and durability.
2Reliability
If the entire movement plate is replaced when worn to ensure functionality, then reliability is restored, but manufacturing cost increases significantly
Solution Approach 1:
The patent segments the movement plate into a durable base structure and a replaceable surface layer. When wear occurs, only the hardened surface layer or coating needs to be renewed or replaced, rather than discarding the entire plate. This segmentation allows for cost-effective maintenance by preserving the valuable base component and replacing only the worn surface material.
Solution Approach 2:
The patent enables recovery and reuse of the base movement plate structure after the surface layer wears out. Instead of discarding the entire plate, the worn surface can be re-hardened, re-coated, or replaced, allowing the base component to be recovered and continue serving, thus reducing replacement costs.
Data Source
Figure 1
Figure 2~3
Figure 4~7
AI summary
A protective device (1) for protecting a structural component, in particular a plate, (2) of a watch movement (3), at a receiving surface provided by said structural component (2) for receiving a complementary bearing surface (51) of a moving part (5). Said protective device (1) includes at least one insert (6) having a sliding surface (7) of greater surface hardness than that of said structural component (2), said insert (6) being attached to or within said structural component (2) so that its sliding surface (7) coincides with said receiving surface.