Linecard Holder System for Chassis Securing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for securing a linecard to a chassis often result in insufficient or excessive connector engagement due to manufacturing tolerances, leading to poor electrical connections, especially in RF connectors, where excessive pressure can cause deflection of the midplane and impact RF performance.
Innovation Solution
A holder system with a pin, wedge, and retainer is used to secure the linecard to the chassis, generating frictional holding forces without applying additional pressure on the connectors, allowing for consistent connector engagement and maintaining the connectors in a fully mated position without closing the gap between the linecard and chassis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the linecard is secured to the chassis with a screw at the front panel flange, then the linecard is locked into place, but manufacturing tolerances cause insufficient or excessive connector engagement
Solution Approach 1:
The securing mechanism is divided into two independent functions: (1) the screw provides lateral positioning stability by securing the linecard carrier to the chassis, and (2) the ejector flange provides longitudinal positioning by engaging with the card guide bend. This segmentation allows each component to handle specific positioning requirements independently, eliminating the need for the screw to simultaneously provide both lateral and longitudinal positioning, thereby resolving the connector engagement precision issue caused by manufacturing tolerances.
Solution Approach 2:
The ejector flange acts as an intermediary component between the linecard carrier and the card guide. It transfers the longitudinal positioning function from the screw-connector interface to the flange-card guide interface, allowing the connector-midplane interface to focus solely on electrical connection without bearing positioning stresses. This intermediary structure absorbs manufacturing tolerances and prevents them from affecting connector engagement precision.
2Reliability
If the linecard is over long or the chassis under long due to manufacturing tolerances, then locking the linecard may result in excessive pressure on the connector and midplane, but reducing pressure may compromise connection reliability
Solution Approach 1:
The ejector flange serves as a mediator that absorbs longitudinal dimensional variations between the linecard and chassis. By providing a dedicated longitudinal positioning interface with the card guide, it prevents these variations from being transmitted as excessive pressure to the connector-midplane interface, thereby maintaining connection reliability without compromising component integrity.
Solution Approach 2:
The longitudinal positioning function is extracted from the screw-connector interface and relocated to the ejector flange-card guide interface. This extraction removes the source of excessive pressure from the connector and midplane, allowing the electrical connection to maintain reliability without being subjected to harmful mechanical stresses from manufacturing tolerances.
3Strength
If multiple linecards are secured with screws, then each linecard is firmly attached, but cumulative pressure may cause the midplane to deflect, resulting in poor electrical connection
Solution Approach 1:
The attachment system is segmented into two independent functions: the screw provides lateral attachment strength to secure the linecard carrier to the chassis, while the ejector flange provides longitudinal positioning stability by engaging the card guide. This segmentation ensures that cumulative pressures from multiple linecards are directed to the chassis structure through the flange-card guide interface rather than being transmitted to the midplane through the connectors, thereby maintaining both attachment strength and midplane structural stability.
Solution Approach 2:
The ejector flange acts as an intermediary that intercepts and redirects longitudinal forces from multiple linecards before they can be transmitted to the midplane. By providing a dedicated force transmission path through the card guide, it protects the midplane from cumulative deflection while maintaining firm attachment of each linecard through the screw-flange mechanism.
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 solution ensures consistent and reliable electrical connector engagement across multiple linecards, reducing signal noise and maintaining proper RF performance by distributing forces evenly and avoiding excessive pressure on the connectors.
Implementation Method 1
friction between the wedge and the chamfered surface removably holds the linecard relative to the chassis
Data Source
AI summary
A holder secures a linecard to a chassis. The holder acts as a releasable expansion bolt. To alleviate tolerance requirements for the linecard and/or chassis, the holder secures with minimal additional pressure being applied to force the linecard against the chassis. Rather than screwing a linecard face plate to the chassis card guide, the holder locks the linecard in place without requiring movement of the face plate against the chassis card guide. A gap may remain between the face plate and the chassis, substantially allowing for a desired amount of insertion of electrical connectors without adverse pressure or movement caused by the securing.