Sewing Machine Feed Dog Mounting Mechanism with Lever and Stopper
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Solution Overview
Problem
The existing feed dog mounting mechanism in sewing machines requires high pressing force, making it burdensome for operators and reducing operating efficiency during the mounting process.
Innovation Solution
A feed dog mounting/unmounting mechanism that includes a lever and stopper system, where the lever is slidably positioned on the feed base and held by a stopper, allowing the feed dog to be fixed between inclined fixing portions without needing to overcome the high pressing force, thereby simplifying the mounting process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pressing member is used to maintain the mounting state of the feed dog, then the feed dog can be securely fixed, but the mounting process becomes burdensome due to the need to overcome high pressing force
Solution Approach 1:
The lever is designed to be movable between a first position (for mounting) and a second position (for fixing). When the lever is in the first position, it does not apply pressing force to the feed dog, allowing easy mounting. When moved to the second position, it applies pressing force to securely fix the feed dog. This dynamic positioning resolves the contradiction between easy operation and reliable fixation.
Solution Approach 2:
The fixing mechanism is segmented into two distinct functional states: a mounting state where the lever is positioned to allow feed dog insertion without resistance, and a fixing state where the lever is positioned to apply securing force. This segmentation allows the operator to choose the appropriate state for each phase of the operation, eliminating the need to overcome high pressing force during mounting.
2Reliability
If high pressing force is applied by the pressing member, then the feed dog mounting state is maintained reliably, but the operating efficiency during mounting is reduced
Solution Approach 1:
The lever's position is dynamically changed based on operational needs. During mounting, the lever is positioned to minimize resistance, improving efficiency. After mounting, the lever is moved to apply full pressing force for reliable fixation. This dynamic adjustment eliminates the trade-off between reliability and productivity.
Solution Approach 2:
The lever is preliminarily positioned in the first position before mounting begins, creating a low-resistance environment for feed dog insertion. This preliminary positioning action ensures that the mounting operation can proceed efficiently without the need to overcome high pressing forces, while still achieving reliable fixation afterward.
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 mechanism improves operating efficiency by allowing the feed dog to be mounted and unmounted with reduced manual effort, enhancing the ease of use and speed of the process.
Implementation Method 1
the lever force-applying member is a spring
Implementation Method 2
the stopper force-applying member is a spring
Data Source
AI summary
In feed dog mounting/unmounting mechanism, lever is slidably provided to feed base in the front-rear direction, and is forced backward by a lever force-applying spring. Upon sliding lever rearward, fixing target portion of feed dog 22 is fixedly held by base-side fixing portion of feed base and lever-side fixing portion of lever arranged in the front-rear direction. Stopper is provided to feed base so as to be movable in the upper-lower direction, and holds lever. When feed dog is mounted, stopper is pressed downward by feed dog, which moves stopper so as to allow lever to slide. With this, lever is slid due to force applied by the lever force-applying spring, thereby allowing fixing target portion to be held, interposed between base-side fixing portion and lever-side fixing portion.