Weft Braking Device Torque Compensation
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Solution Overview
Problem
Conventional weft braking devices for accumulator yarn feeders suffer from uneven braking action due to misalignment and unbalanced torque, leading to increased wear and maintenance needs, and complex substitution processes.
Innovation Solution
A weft braking device with an articulated joint and elastic means, utilizing a ball joint mechanism and magnetic coupling, which compensates for misalignments and balances torque, ensuring even braking action and simplifying the substitution process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a radial system of springs is used to compensate misalignments between the drum and braking body, then misalignment compensation is improved, but the thrust in eccentric position generates torque that increases wear on lateral guides and requires frequent lubrication
Solution Approach 1:
The patent replaces the radial spring system with a universal joint mechanism that allows angular misalignment compensation without generating eccentric thrust. The universal joint's spherical geometry enables the braking body to accommodate misalignments while maintaining axial thrust alignment, eliminating the harmful torque on lateral guides that caused wear in the spring-based system.
Solution Approach 2:
Instead of using springs that push radially outward from an eccentric position, the invention inverts the approach by using a universal joint that allows the braking body to pivot and self-align. This reverses the cause-effect relationship: rather than the thrust creating misalignment compensation, the misalignment tolerance of the joint enables proper thrust application without eccentric loading.
2Device complexity
If the braking body is supported in a cantilever fashion with respect to the articulation axes of the joint, then the structure is simplified, but the weight of the braking body has an unbalancing effect that compromises the evenness of the braking action
Solution Approach 1:
The patent introduces elastic means (springs) that act against the torque generated by the weight of the braking body. These elastic elements are positioned to counterbalance the gravitational torque, ensuring that the braking body remains evenly positioned against the drum surface throughout its operation, thus maintaining uniform braking action despite the cantilever support configuration.
Solution Approach 2:
The elastic means are pre-loaded to compensate for the weight-induced torque before the braking body begins operation. This beforehand cushioning ensures that the braking body starts in a properly balanced position and maintains even contact with the drum, preventing the unbalancing effect of cantilever support from compromising braking uniformity.
3Device complexity
If two axes of the joint do not intersect and the joint is not a ball joint, then the structure is simplified, but the precision and evenness of the braking action is compromised
Solution Approach 1:
The patent employs a universal joint with spherical geometry that allows the braking body to pivot freely in multiple directions. The spherical articulation surfaces enable precise angular adjustment and maintain point contact, ensuring that the braking body can self-align with the drum surface while maintaining high precision in the braking action, superior to non-intersecting axis configurations.
4Stability of the object's composition
If conventional substitution procedures are used for the braking body, then the device structure is maintained, but the substitution operation is inconvenient and complicated
Solution Approach 1:
The braking body is designed as a separable module that can be independently removed and replaced. The universal joint connection allows the braking body to be detached from the actuator assembly without disassembling the entire device, enabling convenient substitution operations while maintaining the overall device structure and configuration.
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 provides a precise and even braking action along the circumference of contact, reducing wear and simplifying maintenance, while allowing for easy substitution of the braking body.
Implementation Method 1
functionally associated with elastic means which act against the torque generated by the weight of the braking body in order to balance it
Implementation Method 2
utilizing a ball joint mechanism and magnetic coupling
Data Source
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AI summary
A yarn feeder (10) provided with a drum (12) which supports, wound thereon, a yarn (Y) which can be unwound upon request of a downstream machine, an annular braking body (16) is coaxially pushed against an output end (12a) of the drum (12) by actuation means (18) which act axially; an articulated joint (24) is functionally interposed between the actuation means (18) and the braking body (16); the weight of the braking body (16) generates a torque about at least one articulation axis (X, Z) of the joint (24), against which elastic means (34) act which are functionally associated with the joint (24).