Sewing Machine Presser Foot Lifting Mechanism Design
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Solution Overview
Problem
The presser-foot lifting and lowering mechanisms in sewing machines, operated by either a manual lever or knee lifter, are complex and require numerous parts, complicating production and assembly.
Innovation Solution
A simplified mechanism using a lifter operating plate, pivot rod, presser-foot bar lifting and lowering plate, and knee lifter mechanism, with adjustable features for height and pressure, reduces the number of parts and simplifies the lifting and lowering process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the presser-foot lifting and lowering mechanisms are composed individually for manual lever operation and knee lifter operation, then each mechanism can function independently, but the overall mechanism becomes complicated and the number of parts increases
Solution Approach 1:
The patent combines the manual lever lifting mechanism and knee lifter lowering mechanism into a single integrated presser-foot lifting and lowering device. The manual operation lever (31) and knee operation lifter (51) both actuate the same presser-foot bar (8) through a shared linkage system involving the lifter operating plate (38), pivot rod (41), and presser-foot bar lifting and lowering plate (27), eliminating the need for separate independent mechanisms while maintaining reliable operation for both lifting and lowering functions
2Adaptability or versatility
If separate lifting and lowering mechanisms are used, then each operation mode can be optimized independently, but the production process becomes complicated
Solution Approach 1:
The patent creates a universal presser-foot lifting and lowering device that serves multiple functions through a single mechanism. The same linkage system (lifter operating plate, pivot rod, joining links) handles both the lifting operation via manual lever and the lowering operation via knee lifter, allowing the mechanism to be optimized for overall performance rather than requiring separate optimizations for each operation mode, thereby simplifying production
3Ease of operation
If individually composed lifting and lowering mechanisms are implemented, then specific operational requirements can be met, but the number of parts increases
Solution Approach 1:
The patent merges the lifting and lowering mechanisms into a single integrated system where common components (lifter operating plate, pivot rod, joining links, presser-foot bar) serve dual purposes. The manual lever (31) and knee operation lifter (51) both control the same presser-foot bar (8) through the shared linkage, significantly reducing the total number of parts compared to having completely separate mechanisms while still fulfilling all operational requirements
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
The solution allows for easier production, reduced part count, adjustable presser-foot lifting quantity, and adjustable pressure settings, enhancing operational efficiency and ease of use.
Implementation Method 1
a presser-foot pressure-spring which is attached to an upper direction of a presser bar holder which is fixed firmly to the presser-foot bar, a presser-foot pressure-adjusting plate which repels elastically the presser-foot pressure-spring from an upper direction
Data Source
AI summary
When lifting and lowering the presser-foot by either of the manual operation lever and the knee operation lifter, the composition of the lifting and lowering mechanism can be simplified, the number of parts can be reduced and the production can be performed easily. The present invention is provided with a presser bar lifting and lowering mechanism (30) which has: a lifter operating plate which is disposed upon a pedestal (2a) which supports an arm (2) upon a bed (3) and which is vertically movable depending on a vertical movement operation of a manual operation lever (31); a pivot rod in which one end is joined to the lifter operating plate via a first joining link; and a presser-foot bar lifting and lowering plate which is joined to a second joining link which is joined to the other end of the pivot rod, and which is joined to the presser-foot bar via a presser bar holder which is fixed to the presser-foot bar. The present invention is provided with a knee lifter mechanism (50) which is disposed upon a right lower end (3a) of the bed, which is equipped with a knee operation lifter (51), and which has a knee lifter drive arm which rotates by a swing of the knee operation lifter, wherein the knee lifter drive arm is joined to the lifter operating plate.