Interrupt Cam Stabilizes Needle Selector in Flat Knitting Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing needle selecting system in flat knitting machines experiences unstable adhesion and separation of the armature with the adhering surface due to fluctuations in carriage and needle bed spacing, leading to needle selecting mistakes, especially at higher knitting speeds and when the machine is fine-gauged.
Innovation Solution
The introduction of an interrupt cam that supports the selector by abutting the elastic leg piece, stabilizing the adhesion and separation of the armature with the adhering surface, and positioning the needle selecting actuator on the upper surface of the needle bed to reduce moment effects and allow for miniaturization of the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the knitting speed is increased, then productivity is improved, but the adhesion and separation of the armature becomes unstable causing needle selecting mistakes
Solution Approach 1:
The interrupt cam performs preliminary action by separating the armature from the adhering surface before the electromagnetic actuator completes its reciprocation. This pre-separation ensures that even at high speeds, the armature is already disengaged and ready for the next selection cycle, preventing selection mistakes while maintaining high productivity
Solution Approach 2:
The interrupt cam introduces periodic action by rhythmically interrupting the adhesion between the armature and adhering surface during each reciprocation cycle. This periodic interruption creates reliable separation timing that synchronizes with the high-speed operation, ensuring stable needle selection even at increased knitting speeds
2Manufacturing precision
If the machine is fine-gauged, then manufacturing precision is improved, but the area of the armature becomes small causing unstable adhesion and separation
Solution Approach 1:
The interrupt cam acts as an intermediary mechanical element that provides reliable separation between the armature and adhering surface. For fine-gauged machines with small armature areas, this intermediary cam ensures sufficient mechanical separation force without relying solely on the limited magnetic release force, thereby maintaining adhesion stability even when the armature area is reduced
Solution Approach 2:
The interrupt cam changes the mechanical parameter of separation force by providing additional mechanical leverage through its cam profile. This compensates for the reduced magnetic force available in fine-gauged machines with smaller armatures, ensuring that adhesion and separation remain stable despite the reduced component size
3Ease of manufacture
If the spring supporting point is positioned away from the adhering surface, then ease of manufacture is improved, but a large moment generates causing unstable adhesion and separation
Solution Approach 1:
The interrupt cam introduces a new dimensional element by acting on the selector from a different spatial location (from the carriage side rather than from the adhering surface side). This dimensional change allows the spring supporting point to be positioned for ease of manufacture while the cam provides the necessary moment counteraction from a different direction, resolving the stability issue without compromising manufacturability
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 configuration stabilizes the adhesion and separation of the armature, reducing needle selecting mistakes and enabling stable operation at higher speeds and fine gauges by minimizing the influence of microscopic fluctuations and moment effects.
Implementation Method 1
an adhering surface 10s for adhering one part of the selector by a magnetic force
Data Source
Figure 1
Figure 2
Figure 3(A)~3(D)
AI summary
To provide a needle selecting system of a flat knitting machine capable of stably selecting a needle compared to prior art. A needle selecting system 1 including a selector 4 configuring one part of a knitting needle 200, and a needle selecting device 2 arranged in a carriage 300 that reciprocates in a longitudinal direction of a needle bed 100 is provided. The selector 4 includes an armature 43 and an elastic leg piece 44 extending towards a tail end side opposite to a needle bed gap side. The needle selecting device 2 includes a needle selecting actuator 10 and an interrupt cam 20. The interrupt cam 20 is arranged bulging out at a position facing the needle selecting actuator 10, and cuts in between the armature 43 and the elastic leg piece 44 of the selector 4 to spread the spacing between the armature 43 and the elastic leg piece 44 when the carriage 300 travels on the needle bed 100. As a result, the selector 4 is supported by the carriage 300 in which the interrupt cam 20 is arranged.