Shoulder Strap Assembly Device Single Insertion Finger
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Solution Overview
Problem
Existing methods for assembling adjustable garment straps, such as bra straps, face challenges with tape alignment defects and variations in loop length due to complex devices requiring multiple insertion fingers, leading to operational faults and increased production costs.
Innovation Solution
A method and device using a single insertion finger to guide and secure the ribbon through a ruler, with a transfer gripper holding the tape upstream and rotating the ruler to ensure precise alignment and constant loop length, allowing for simpler and more reliable assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple insertion fingers are used to thread the tape through the ruler slots, then the tape can be guided through the slots, but the device complexity increases and alignment defects occur
Solution Approach 1:
The threading process is divided into distinct phases: first threading the tape through the first slot, then rotating the ruler 180 degrees, and finally threading through the second slot. This segmentation allows a single insertion finger to perform the function that previously required multiple fingers, reducing device complexity while maintaining reliability
Solution Approach 2:
The ruler is made rotatable about its central crosspiece, transforming from a static component to a dynamic one. This rotation capability enables the single insertion finger to access both slots sequentially after the 180-degree rotation, eliminating the need for multiple fixed insertion fingers and resolving the contradiction between reliability and device complexity
2Device complexity
If the ruler is rotated 180 degrees after threading the first slot, then the second slot becomes accessible to the same insertion finger, but the positioning precision must be maintained
Solution Approach 1:
The ruler's rotation mechanism serves its own positioning function by returning to a predetermined initial position after the 180-degree rotation. This self-positioning capability ensures that the second slot is correctly oriented for the insertion finger without requiring additional complex positioning devices, thus maintaining manufacturing precision while reducing device complexity
Solution Approach 2:
The complex multi-finger mechanical positioning system is replaced by a simpler rotation mechanism with predetermined stop positions. The ruler rotates 180 degrees and returns to a fixed initial position, using mechanical stops or reference features to ensure precise alignment, thereby maintaining manufacturing precision with fewer components
3Device complexity
If a single insertion finger is used to thread both slots, then the device is simpler, but the tape may not be correctly held during insertion
Solution Approach 1:
The transfer gripper acts as an intermediary device that holds the tape upstream of the ruler and feeds it to the insertion finger. This intermediary ensures the tape is correctly positioned and held during the insertion process, compensating for the reduced capability of using only a single insertion finger, thus maintaining reliability while reducing device complexity
4Manufacturing precision
If multiple threading operations are performed sequentially, then the loop length can be controlled, but the production time increases
Solution Approach 1:
The threading operations are performed in continuous sequence without interruption: the insertion finger threads the first slot, the ruler rotates 180 degrees, and the same finger immediately threads the second slot. This continuous operation maintains loop length consistency through controlled sequential actions while minimizing idle time, thus balancing manufacturing precision with improved productivity
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
According to the invention, a length of ribbon (7) is brought by a transfer grip (20) and a telescopic guide (27) towards first support means (29) holding a figure-of-eight ring (6). By successive inversions of the figure-of-eight ring (6) and translations in a direction of progression (30), the ribbon (7) is fed several times through the slots (8, 9) of the figure-of-eight ring (6) and through a hoop (5) using a single insertion poker (21). The quality of the resulting shoulder strap is improved.