Sealing Plug Assembly With Interference Fit for Low-Force Installation

The sealing plug is divided into two separate components: a sleeve that remains in the workpiece and a stem that is inserted through the sleeve. This segmentation allows the sealing function to be distributed - the sleeve provides the sealing interface with the workpiece hole while the stem provides the anchoring function, thereby reducing the installation force required compared to a single integrated plug design.

The stem is inserted through the hollow interior of the sleeve, creating a nested configuration. The stem passes through the first bore portion and is anchored in the second bore portion, while the sleeve remains positioned in the workpiece hole. This nesting arrangement allows both components to work together synergistically to achieve reliable sealing with reduced installation forces.

By separating the sealing plug into a sleeve and a stem, each component can be manufactured using simpler, more standard processes. The sleeve can be produced as a simple hollow cylinder with appropriate bore dimensions, while the stem can be manufactured as a solid rod with a weakened portion. This segmentation eliminates the need for complex cold-heading, thread-rolling, and heat treatment operations required for traditional integrated plug designs.

The complex manufacturing operations (cold-heading, thread-rolling, heat treatment) are extracted from the design and eliminated. Instead, the invention uses simpler manufacturing approaches: the sleeve is made as a hollow structure and the stem as a solid structure with a controlled weakened portion, both of which can be produced with standard machining or forming operations.

The stem is designed with a weakened portion that is positioned to break at a controlled location during installation. This weakened portion acts as a cushioning element that absorbs the impact and misalignment forces during insertion, preventing these forces from being transmitted to the sleeve and causing damage. The stem breaks in a controlled manner rather than transmitting shock to the more critical sleeve component.

The stem is designed as a disposable component that is intended to break during or after installation. The weakened portion is deliberately created to fail at a predetermined point, sacrificing the stem to protect the more valuable and reusable sleeve and workpiece. This approach prioritizes protecting the critical sealing interface over preserving the installation tool or plug components.

The sealing function is segmented between the sleeve and stem, allowing the sleeve to provide the sealing interface over an extended portion of the workpiece hole while the stem provides anchoring over a shorter distance. This segmentation enables the sealing reliability to be improved through the sleeve's extended presence in the hole without requiring the entire plug assembly to be proportionally longer.

The nested configuration of the stem within the sleeve allows for optimized length distribution. The sleeve can extend further into the workpiece hole to provide reliable sealing over a longer distance, while the stem is nested within and only requires sufficient length to provide anchoring through the weakened portion breakage mechanism. This nesting arrangement decouples the length requirements for sealing versus anchoring functions.