Method And Apparatus For Testing Cigarettes Or The Like

What is this patent about?

'678 is related to the field of testing rod-shaped articles, specifically cigarettes and similar smokers' products, for defects in their wrappers. Traditional pneumatic testing methods are limited in their ability to detect certain types of defects, such as plugged holes or cosmetic imperfections like tobacco crumbs in the wrapper seam. This patent addresses the need for a more comprehensive testing method that can identify a wider range of defects, including those affecting appearance and structural integrity.

The underlying idea behind '678 is to use an optoelectronic system to scan the entire surface of a cigarette wrapper as it rotates. The cigarette is briefly decelerated and rotated about its axis while one or more light beams are directed at the wrapper. By analyzing the reflected or transmitted light, the system can detect imperfections such as holes, frayed ends, or protuberances that would otherwise go unnoticed.

The claims of '678 focus on a method of testing successive rod-shaped articles by conveying them sideways along a path, decelerating and rotating them, and then electro-optically scanning each article during rotation. This includes monitoring the condition of the tubular wrappers, interrupting the sidewise movement to reduce speed to zero, and turning the articles through approximately 360 degrees to ensure complete surface coverage.

In practice, the invention uses a combination of a drying conveyor and a rotary element to achieve the deceleration and rotation. The cigarette is transferred from a conveyor onto the drying conveyor and simultaneously engaged by the rotary element, causing it to rotate. Photosensitive optoelectrical testing units then scan the rotating wrapper. One unit detects protuberances by sensing interruptions in a light beam, while another detects holes and other defects by analyzing reflected light patterns.

This approach differs from prior solutions by testing articles without removing them from their normal processing path, minimizing handling and potential damage. Unlike pneumatic systems, it can detect a broader range of defects, including those affecting appearance. The synchronization of the scanning with the rotation ensures that the entire wrapper surface is inspected, providing a more reliable and comprehensive quality control process.