Double-Cylinder Knitting Machine Needle Transfer via Fixed Cams
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Solution Overview
Problem
Current double-cylinder circular knitting machines for hosiery require complex movable cams to transfer needles between cylinders, increasing machine complexity and necessitating additional control devices for reliable operation, especially during power failures, and require a large needle cylinder sector for correct operation.
Innovation Solution
A double-cylinder circular knitting machine design that uses fixed cams and actuation elements with movable heels that transition between active and inactive positions to transfer needles between cylinders, eliminating the need for actuators and simplifying the transfer process, allowing for precise and reliable needle transfer without movable cams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If movable cams are used to transfer needles between cylinders, then needle transfer can be achieved, but machine complexity increases and additional control devices are required
Solution Approach 1:
The patent extracts the movable cam mechanism from the system and replaces it with fixed cams combined with selectable actuation elements. The actuation elements can be selectively engaged or disengaged from the fixed cams to achieve needle transfer without requiring the entire cam mechanism to be movable, thus reducing machine complexity while maintaining needle transfer capability
Solution Approach 2:
The patent introduces dynamically selectable actuation elements that can be engaged or disengaged from fixed cams based on knitting patterns. This dynamic selection mechanism allows the machine to achieve variable needle transfer functionality without requiring movable cams, resolving the contradiction between adaptability and device complexity
2Adaptability or versatility
If movable cams are used for needle transfer, then transfer operation is possible, but reliability during power failures decreases due to additional control devices
Solution Approach 1:
By removing the movable cam and its associated actuator control system, the patent eliminates the reliability issues associated with power failures affecting movable components. The fixed cam system with selectable actuation elements requires no powered control, inherently improving reliability during power failures while maintaining needle transfer capability
Solution Approach 2:
The fixed cam system with selectively engaged actuation elements operates passively without requiring external power or control devices. The mechanism relies on the mechanical engagement between fixed cams and actuation elements, which can be controlled by simpler, more reliable means such as gravity, springs, or manual selection, thereby improving operational reliability
3Adaptability or versatility
If movable cams are used for needle transfer, then transfer function is achieved, but the needle cylinder sector required increases
Solution Approach 1:
The patent segments the needle cylinder into zones with different actuation element engagement states. By selectively engaging actuation elements in specific segments of the cylinder, the fixed cam system can achieve needle transfer functionality without requiring a large continuous sector, thus reducing the space required on the needle cylinder
Data Source
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AI summary
A double-cylinder circular knitting machine for hosiery or other knitted articles, which comprises a lower needle cylinder (1) which has a vertical axis and an upper needle cylinder (1') which is arranged above and coaxially with respect to the lower needle cylinder (1). Mutually aligned axial slots (2) are formed on the lateral surface of the lower needle cylinder (1) and on the lateral surface of the upper needle cylinder (1'). Each of the axial slots (2) of the lower needle cylinder (1) and of the upper needle cylinder (1') accommodates an actuation element (10) which can engage a needle (6) to be actuated and is provided with a fixed heel (3a), which protrudes radially from the axial slot (2), and with a heel (4a) which can be extracted radially on command from the axial slot (2). Cams (8,9,8',9') for actuating the actuation elements (10) are arranged around the lower needle cylinder (1) and around the upper needle cylinder (1') and can be engaged by the fixed heels (3a) and by the movable heels (4a) in the extracted position. The transfer of a needle (6) from one needle cylinder (1) to the other (1') is performed by means of fixed cams (51,52) and by means of a selection device (23), which produces the transition into the extracted position of the movable heel (4a) exclusively of the actuation elements (10) that correspond to the needles (6) to be moved to the lower needle cylinder (1).