Insertion-Locking Pin and Grommet for One-Step Fastener Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pin and grommet fasteners in the automotive industry require separate steps for inserting the pin into the grommet and seating it within the joining part, which can be cumbersome and inefficient.
Innovation Solution
An insertion-locking pin and grommet fastener design featuring a pin with locking members that engage the grommet's leg members to retain the pin in a shipping configuration, allowing automatic locking upon insertion into a joining part, eliminating the need for additional seating steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the pin is assembled to the grommet in a partial, temporary, or shipping position, then the end user only needs to handle a single assembly, but the pin must still be seated within the grommet as a separate step after insertion into the joining part
Solution Approach 1:
The pin is pre-assembled to the grommet in a shipping configuration during manufacturing, so that when the fastener is inserted into the joining part, the pin is automatically driven to its final seated position within the grommet. This preliminary assembly eliminates the need for separate handling of pin and grommet, and the automatic seating during insertion eliminates the need for a separate seating step.
Solution Approach 2:
The driving protrusion on the pin automatically engages the periphery of the joining aperture during insertion, which self-drivenly moves the pin from its shipping position to its final seated position within the grommet. The fastener structure itself performs the seating action during normal insertion, without requiring external intervention or additional steps.
2Productivity
If the pin is inserted into the grommet and seated as separate steps, then the locking mechanism can be simple, but the assembly process becomes cumbersome and inefficient
Solution Approach 1:
The invention merges the pin insertion and seating operations into a single integrated action. When the assembled pin-grommet fastener is inserted into the joining part, the driving protrusion automatically drives the pin to its final position within the grommet, combining what were previously separate steps into one continuous motion.
Solution Approach 2:
The pin and grommet are pre-assembled in a shipping configuration before use, so that the end user receives a ready-to-install unit. During insertion into the joining part, the pin is automatically driven to its final seated position, eliminating the need for separate insertion and seating operations and significantly improving assembly efficiency.
3Stability of the object's composition
If the pin has locking members to engage the grommet leg members, then the pin is retained in a shipping configuration, but additional locking members increase the complexity of the pin structure
Solution Approach 1:
The pin has different sections with different functions: a driving protrusion for automatic seating during insertion, and locking members (protrusions or recesses) for retaining the pin in the shipping configuration. Each local feature is optimized for its specific function, allowing the pin to maintain stability in shipping while enabling automatic assembly during installation.
Solution Approach 2:
The locking members are designed to maintain the pin in a fixed shipping configuration during handling and transport, but during insertion into the joining part, the driving protrusion automatically overcomes this retention to drive the pin to its final seated position. The structure dynamically transitions from a retained state to a freely movable state during the insertion process.
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A pin and grommet fastener is assembled into a shipping configuration in which the pin (31) is retained in a first position relative to the grommet (24) with longitudinally extending leg members of the grommet in an unexpanded state. Cooperating members are provided on the pin and the grommet to engage each other in a locking configuration in which the pin is retained in a second position relative to the grommet causing the longitudinally extending leg members to be in a laterally expanded state. A driving member (38) is provided on the pin to engage a periphery of an aperture of a joining part to cause the joining part to automatically drive the pin from the first position to the second position simultaneously with the insertion of the assembled pin and grommet into the aperture of the joining part.