Device For Feeding And Checking Layers Of Cigarettes In Cigarette Packaging Machines

What is this patent about?

'955 is related to the field of cigarette packaging machinery, specifically addressing the problem of detecting incomplete layers of cigarettes before they are wrapped. Traditional methods relied on electromechanical feeler pins or optical sensors, both of which suffered from reliability issues. Feeler pins could be fooled by irregularly positioned cigarettes, while optical sensors were prone to malfunction due to accumulating tobacco dust.

The underlying idea behind '955 is to use a light-based detection system that is less susceptible to dust and cigarette positioning errors. Instead of shining light along the cigarette axis, the invention shines light transversely across the path of the cigarette layer as it's being transferred. By placing photosensors underneath each cigarette position, the absence of a cigarette is reliably detected by the increased light reaching the sensor.

The claims of '955 focus on a device for feeding and checking layers of cigarettes in cigarette packaging machines. The device includes transparent sheets that guide the cigarette layer, a light source positioned above the layer, and photosensitive elements positioned below, each aligned with a potential cigarette location. The key is the transverse illumination and detection arrangement.

In practice, as a layer of cigarettes is pushed from the hopper towards the wrapping station, it passes between the transparent sheets. A light source above shines down through a slot, illuminating the area where each cigarette should be. If a cigarette is missing, the corresponding photosensor below receives the light, triggering a signal. This signal is then used to activate an ejection mechanism, removing the defective bundle from the production line.

The differentiation from prior art lies in the transverse illumination and the physical arrangement of the components. By shining light across the cigarette path, the system becomes less sensitive to minor misalignments or variations in cigarette length. Furthermore, the transparent sheets help to keep the photosensors clean, reducing the impact of tobacco dust and improving the overall reliability of the detection process.