Weft Feeder Drum with Embedded Inductive Sensors
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Solution Overview
Problem
Existing weft feeders with direct optic sensors face limitations in flexibility, particularly with short weft lengths, low-thread counts, and dark or reflective threads, leading to reduced sensitivity and selectivity, and the ballooning effect during thread collection.
Innovation Solution
The weft feeder integrates SMD-type LEDs and phototransistors embedded within the drum sectors, with a flexible printed circuit and inductive power supply coils housed in magnet cups, allowing for compact design and improved signal stability, and a control block with receiving sensors and an electromagnetic stopping device for precise thread control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct optic sensors (emitting sensors on drum, receiving sensors on support arm) are used to detect thread presence, then signal strength and stability are improved, but the drum cannot be mechanically connected to the weft feeder body, requiring complex power supply arrangements (batteries or induction coils)
Solution Approach 1:
The patent replaces the mechanical connection system with an inductive coupling system. Instead of using batteries or complex cable arrangements to power the emitting sensors on the drum, the invention uses electromagnetic induction through coils positioned on the drum and corresponding coils on the feeder body, enabling wireless power and signal transmission while maintaining sensor functionality.
Solution Approach 2:
The inductive coupling system serves multiple functions simultaneously: it provides power supply to the emitting sensors, enables data transmission between the drum and feeder body, and maintains mechanical flexibility of the drum rotation. This multi-functional approach eliminates the need for separate power supply systems.
2Adaptability or versatility
If the drum diameter is reduced to improve flexibility with short weft lengths, then adaptability is improved, but the inductive power supply coils and emitting sensors cannot be properly housed
Solution Approach 1:
The patent embeds the emitting sensors and inductive power supply coils within the drum structure itself, nesting these components into the drum's internal cavities and layers. This nesting approach minimizes the external dimensions of the drum while accommodating all necessary components, enabling reduced drum diameter for short weft lengths without compromising component housing.
Solution Approach 2:
The invention utilizes the radial and axial dimensions of the drum structure to arrange components efficiently. By positioning coils and sensors at different radial depths and axial locations within the drum, the design accommodates multiple components in a compact three-dimensional arrangement, allowing smaller drum outer diameter while maintaining internal component spacing.
3Measurement precision
If emitting sensors are placed on the drum surface with inductive power supply, then direct sensor detection is achieved, but the minimum drum diameter increases due to component housing requirements
Solution Approach 1:
The emitting sensors and inductive coils are nested within recesses and cavities formed in the drum structure, allowing these components to be housed without increasing the external drum diameter. The components are integrated into the drum's internal geometry rather than adding external protrusions.
Solution Approach 2:
The patent uses thin-walled structural design for the drum, optimizing the wall thickness to accommodate internal components while maintaining structural integrity. The drum shell is designed with minimal necessary thickness to house the sensors and coils, reducing the overall diameter requirement while preserving mechanical strength.
4Measurement precision
If SMD LEDs and phototransistors are embedded within drum sectors with flexible printed circuits, then sensitivity and selectivity for various thread conditions are improved, but manufacturing complexity increases
Solution Approach 1:
The patent replaces traditional rigid circuit board connections with flexible printed circuits that can be conformally mounted on the curved drum surface. This substitution enables the integration of SMD sensors while maintaining manufacturing feasibility through flexible circuit techniques rather than rigid PCB assembly on curved surfaces.
Solution Approach 2:
The invention uses SMD (surface-mount device) technology for the LEDs and phototransistors, which allows these sensitive components to be mounted directly on the flexible circuit boards. The SMD format enables compact component placement and automated assembly processes, reducing manufacturing complexity despite the precision requirements for sensitivity.
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 enhances flexibility and sensitivity for various thread conditions, reduces the ballooning effect, and maintains a compact design, offering improved thread collection efficiency and quality without increasing the drum's minimum diameter.
Implementation Method 1
through induction supply assemblies comprising a pair of electric coils housed on the weft feeder body and on the drum, respectively
Implementation Method 2
The weft feeder integrates SMD-type LEDs and phototransistors embedded within the drum sectors
Implementation Method 3
emitting/receiving optic sensors arranged on the weft feeder so that the path of the optic radiation between an emitting sensor and a receiving sensor intercepts the thread path
Data Source
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AI summary
A weft feeder device for threads, in particular for weaving looms, of the type comprising a main body (1) within which there is housed an electric motor for the driving of a rotary shaft (2), the rotary shaft (2) driving into rotation, with its middle portion, a rotor (3), and a drum (T) rotatably mounted on the end portion of said rotary shaft (2) and kept fixed by magnetic means (6, 7), and wherein there are furthermore provided pairs of optical emitting/receiving sensors (E, R) are respectively arranged on the drum (T) and on an extension of the main body (1) of the weft feeder device which extends laterally to the lateral surface of the drum (T), said pairs of sensors (E, R) being apt to detect the presence/absence of a thread passing therebetween. The outer surface of said drum (T) consists of multiple independent sectors (4), and said emitting sensors (E) and the relative feeding and control circuit are embedded in the thickness of one (4s) of said sectors (4), arranged opposite said extension (10) of the main body (1) of the weft feeder device.