Rotary Welding Device Anvil Alignment Mechanism
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Solution Overview
Problem
Existing rotary welding devices for absorbent articles face challenges in ensuring accurate and efficient welding within the limited weld time due to high production speeds, requiring precise contact and flatness between welding elements and the absorbent strip.
Innovation Solution
A rotary welding device with a rotary part, supporting elements for the absorbent strip, and a plurality of welding units. Each welding unit has a movable anvil element relative to a welding tip, driven by an articulated system, allowing precise alignment and reduced wear on the drive mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high production speeds are used to meet market demands, then productivity increases, but the weld time available for each welding unit decreases
Solution Approach 1:
The welding process is segmented into two distinct phases: a rapid positioning phase that brings the anvil element close to the welding tip, and a welding phase where the elements are precisely aligned. This segmentation allows the system to maintain high production speeds while ensuring accurate welding within the limited weld time available.
Solution Approach 2:
The anvil element is preliminarily positioned close to the welding tip before the actual welding operation begins. This preliminary positioning action reduces the distance that needs to be covered during welding, enabling faster welding cycles and higher productivity while maintaining weld quality.
2Device complexity
If the anvil element is kept stationary relative to the welding tip, then device complexity is reduced, but manufacturing precision deteriorates due to inability to maintain precise alignment at high speeds
Solution Approach 1:
The anvil element is made dynamic rather than stationary, allowing it to move relative to the welding tip. This dynamic capability enables precise alignment to be maintained at high production speeds, as the anvil can be positioned and aligned exactly where needed during the welding process, rather than relying on fixed positioning that would compromise precision.
3Device complexity
If the articulated system transmits weld forces to the first drive means, then structural simplicity is maintained, but reliability decreases due to increased wear on drive means
Solution Approach 1:
The force transmission function is extracted from the first drive means and positioned elsewhere in the articulated system. By removing the weld forces from the first drive means, the system maintains structural simplicity while significantly improving reliability, as the drive means no longer承受 the wear and load of welding forces.
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 ensures precise alignment and reduced wear on drive mechanisms, maintaining high production speeds while ensuring accurate welding within the limited weld time, thus enhancing the reliability and efficiency of the welding process.
Implementation Method 1
The first movement means of each welding unit comprise at least one articulated system comprising a crank, a conrod which is pivotally connected to the crank, and a lever for supporting the anvil element and oscillating about an axis of oscillation
Implementation Method 2
The oscillation of the lever about the axis of oscillation causes the anvil element to be driven angularly relative to the welding tip from the initial position to the final position
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
This invention relates to a rotary welding device which comprises a rotary part (5) rotating about its axis of rotation (5a), one or more supporting elements (9) for supporting a continuous strip (2), specifically a strip of nappies, supported by the rotary part (5), and a plurality of welding units (6), mounted on the rotary part (5), for welding the continuous strip (2); each welding unit (6) is configured to pass from a non-operating position to an operating position and vice versa; each welding unit (6) comprises a respective welding tip (7) and a respective anvil element (8) which is movable relative to the welding tip (7); each welding unit (6) comprises respective first movement means (15) configured to drive the anvil element (8) in rotation relative to the welding tip (7) from an initial position, where the anvil element (8) is angularly spaced from the welding tip (7), to a final position, where the surface (7a) of the welding tip (7) and the surface (8a) of the anvil element (8) are parallel and aligned with each other along the same axis (V), and vice versa.