In-Ear Headphone Battery Spring Tab Assembly for Unconstrained Expansion
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Solution Overview
Problem
Conventional wireless headphones face issues with antenna frequency detuning due to varying conductive path lengths between the antenna and the PCB ground plane, and batteries may fail improperly during thermal events due to constrained expansion.
Innovation Solution
The wireless headphone architecture features a cap-mounted PCB with a directly connected antenna using LDS and heat stakes, and a battery configuration with spring tabs and pogo pins for unconstrained thermal expansion, enabling reliable electrical connections and blind assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a battery spring tab assembly is used to secure the battery to the housing, then the battery is held firmly in place, but the tab may become deformed or dislodged during assembly or wear over time
Solution Approach 1:
The spring tab assembly is divided into separate functional components: the spring element (providing constant force), the tab (providing engagement), and the battery retainer (providing mounting structure). This segmentation allows each component to be optimized independently - the spring maintains constant engagement force while the tab and retainer provide structural support, preventing tab deformation and dislodgement.
Solution Approach 2:
The invention combines the spring mechanism with the tab structure to create an integrated spring tab assembly. The spring is incorporated directly into the tab assembly, merging the elastic force generation with the mechanical engagement function. This combination ensures the tab remains under constant spring force, preventing dislodgement while distributing mechanical stress away from the tab itself.
2Ease of manufacture
If conventional adhesive or mechanical attachment methods are used to secure the battery, then assembly is simple, but the battery may shift or become loose over time
Solution Approach 1:
The spring tab assembly introduces a dynamic element (the spring) that automatically adjusts to maintain constant engagement force on the battery. Unlike static adhesive or rigid mechanical attachments, the spring dynamically compensates for manufacturing tolerances, thermal expansion, and wear, ensuring the battery remains securely positioned without complex assembly procedures.
3Reliability
If the spring tab assembly is designed with high engagement force to prevent battery movement, then battery positioning is stable, but the spring tab may become deformed during assembly
Solution Approach 1:
By separating the force generation function (spring) from the engagement function (tab and retainer), the design allows the spring to provide high engagement force without requiring the tab itself to be overly complex or fragile. The spring handles the force requirement while the segmented retainer structure provides simple, robust engagement points.
Solution Approach 2:
The spring acts as an intermediary element between the housing and the battery, providing the necessary engagement force without requiring direct complex mechanical coupling. The spring mediates the interaction, allowing stable battery positioning through its elastic properties while keeping the overall assembly process simple and the tab structure straightforward.
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
This design minimizes resonant frequency variations and ensures safe battery failure during thermal events by maintaining consistent conductive path lengths and allowing unconstrained battery expansion, enhancing manufacturing repeatability and safety.
Implementation Method 1
a spring engaged with the battery to apply a force to the battery
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
Systems and methods are directed to a headphone having a headphone cap and a headphone housing. The headphone cap is mechanically coupled to a printed circuit board (PCB) which has a first electrical connector and a second electrical connector. The headphone housing is configured to be mechanically coupled with the headphone cap, and comprises a battery having a third electrical connector and a fourth electrical connector. The third electrical connector is configured to form a first electrical connection with the first electrical connector as a result of the headphone housing being mechanically coupled with the headphone cap. The fourth electrical connector is configured to form a second electrical connection with the second electrical connector as a result of the headphone housing being mechanically coupled with the headphone cap. In mechanically coupling the headphone housing to the headphone cap, the battery is configured to be horizontally adjacent to the PCB.