Sewing Thread Gripping Device With Gas Jet Cleaning
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Solution Overview
Problem
Bookbinding sewing machines face inefficiencies due to the need for blind stitches to prevent thread loosening, which reduces yield, especially in producing small books with fewer signatures, as it requires idle cycles and increases maintenance needs.
Innovation Solution
A gripping device with a crochet and body that slides between open and closed positions, utilizing a gas jet to clean the hook and prevent dirt accumulation, allowing for thread gripping without blind stitches, thereby improving machine performance and reducing maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blind stitches are made to prevent thread loosening, then thread security is improved, but productivity decreases due to idle cycles
Solution Approach 1:
The harmful function of blind stitches (idle cycles) is extracted and eliminated. The patent introduces a gripping device that actively secures threads without requiring blind stitching operations, thereby removing the productivity penalty while maintaining thread security.
Solution Approach 2:
A gripping device acts as an intermediary mechanism between the thread and the book block. This mediator actively grips and secures the thread end without requiring blind stitches, resolving the contradiction by providing thread security through a different mechanism that doesn't consume productive cycles.
2Device complexity
If standard threads are used without gas jet cleaning, then device complexity is reduced, but reliability decreases due to dirt accumulation
Solution Approach 1:
A gas jet (pneumatic) system is introduced to clean the crochet hook surface. This pneumatic cleaning mechanism removes dirt and debris that would otherwise accumulate and compromise thread gripping reliability, while adding minimal complexity compared to mechanical cleaning alternatives.
Solution Approach 2:
The gas jet system enables the thread-clamp device to self-clean during operation. The crochet automatically removes its own contaminants through the gas jet, maintaining reliability without requiring external maintenance intervention or complex mechanical cleaning mechanisms.
3Reliability
If frequent maintenance is performed to prevent thread loosening, then thread security is maintained, but loss of time increases
Solution Approach 1:
The gas jet cleaning system performs preliminary maintenance by continuously removing dirt during operation. This prevents dirt accumulation that would lead to thread loosening, eliminating the need for frequent stopping and manual maintenance while maintaining thread security.
Solution Approach 2:
The gas jet cleaning operates continuously or periodically during machine operation, maintaining the crochet hook surface continuously clean. This continuous action prevents the degradation that would require intermittent maintenance stops, thereby maintaining thread security without time loss.
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
Enhances the reliability and longevity of the thread-clamp, reduces downtime, and maintains high yield by preventing thread loosening and dirt accumulation, allowing for standard thread use without special low-dirt threads.
Implementation Method 1
The body has one or more channels crossing it for conveying a gas jet towards the hook
Data Source
AI summary
A gripping device (200) is proposed for gripping a sewing thread (415) in a bookbinding sewing machine (100). The gripping device (200) comprises a crochet (205) and a body (220) that are slidable reciprocally between an open condition, wherein a hook (215) of the crochet (205) hooks the sewing thread (415), and a closed condition, wherein the hook (215) blocks the sewing thread (415); the body (220) has one or more channels (270) crossing it for conveying a gas jet towards the hook (215). A bookbinding sewing machine (100) comprising one or more gripping devices (200) is also proposed. Moreover, a corresponding method for sewing signatures (115) into book blocks (155) is proposed.