JPH0586178B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a punching device for punching ventilation holes in cigarettes (hereinafter referred to as cigarettes) and other tobacco products.

<Prior Art> As a perforation device for making so-called "aerated" cigarettes, one using a perforation "tool" consisting of a laser source is known. In known types of laser beam perforation devices, tobacco is usually perforated by two techniques. The first method uses a laser source to create a vent hole while the cigarette rotates about its axis, and the second method uses a laser source that creates a vent hole in the cigarette while it rotates around its axis, while the second method uses a laser source that moves the cigarette relative to the laser source without rotating. It uses a movable reflection system designed to direct the laser beam in different directions onto the tobacco to be perforated.

In both of the aforementioned methods, known laser beam devices use a "pulsating" laser source with a frequency such that one hole is drilled with one pulse.

However, when using a pulsating laser source, the
It is practically impossible to use the perforation device described above in conjunction with a high performance cigarette making machine or filter attaching machine designed to produce as many as 10,000 cigarettes.

To do this, the pulse frequency required to punch approximately 30 holes in each cigarette is approximately 5000 Hz;
This means that a relatively large, high power laser source is required. Moreover, such pulse frequencies usually result in irregular, tangled pores with an unacceptable appearance.

<Problems to be Solved by the Invention> The object of the present invention is to provide a laser beam perforation which is free from the above-mentioned drawbacks and is designed to operate smoothly in cooperation with high-productivity cigarette making machines and filter attaching machines. The goal is to provide equipment.

SUMMARY OF THE INVENTION Other features and advantages of the invention will now be described with reference to the accompanying drawings, which illustrate preferred embodiments.

Taking this purpose into consideration, the present invention is designed to be carried on a supply drum 5 which rotates around a first axis, and to supply a second
A cigarette 3 that rotates about its axis relative to the drum.
a laser source 6 and an optical reflection and focusing system designed to divert and focus the beam emitted by the laser source 6 to a specific point on the surface of each cigarette 3 for drilling vent holes in the cigarette; A drilling device 1 comprising: the laser source 6 being designed to emit a continuous beam 7 along the first axis 9; the optical system rotating about the first axis 9; A movable unit 22 designed to deflect the beam 7 toward the first axis 9 and arranged around the first axis 9 successively receives the beam 7 and directs it outward onto the tobacco 3. The present invention relates to a drilling device characterized in that it comprises a fixed reflecting member 23 having a ring-shaped mirror group 25 designed to deflect.

Reference numeral 1 in FIG. 1 designates a punching device designed to punch a ring of holes 2 (FIG. 2) into a number of cigarettes 3. Each cigarette is partially housed inside a seat 4 on the outer periphery of a supply drum which rotates about its own axis at a predetermined constant speed. The device 1 comprises a continuous laser source 6 emitting a beam 7 which is deflected by a fixed mirror 8 arranged along an axis 9 coinciding with the axis of rotation of the drum 5.

The device 1 also comprises a cylindrical body 10 mounted for rotation about its own axis coinciding with the axis 9. The cylindrical body 10 has an outer ring 11 that meshes with an output pinion 12 attached to a motor for driving the cylindrical body 10 at a predetermined constant speed.

Two arms 14 and 15 extend from the end of the cylindrical body 10 facing the drum 5 and support mirrors 16 and 17, respectively, and the mirror 16 receives the beam from the cylindrical body 10 and reflects it. 17 in a direction approximately perpendicular to axis 9.

As shown in FIG.
It is positioned so as to turn along an axis 18 which intersects axis 9 at 9 . The axis 18 coincides with the optical axis of a condensing lens 20 supported on an arm 21 integrated with the arm 15, which lens, assuming that the condensed beam is not deflected further, Arms 14, 15, 21, mirrors 16, 17
It is designed to focus the beam on a point coincident with point 19, irrespective of the angular position about axis 9 of the movable unit consisting of lens 20 and lens 20.

The device 1 is also in the form of a regular polygonal truncated cone and comprises a fixed reflective member 23 placed coaxially with the axis 9 towards the tubular body 10 at its top. The reflective member 2
3 is a filter 2 for each cigarette protruding from the drum 5
It has n faces equal to the number of holes to be drilled in 4. Each surface of the reflecting member 23 is connected to the movable unit 2.
2 receives the focused beam 7 from the lens 20 and reflects it substantially radially outwardly so that the reflected focal point 26 hits the cigarette 3
a reflective surface or mirror 25 formed on the surface of
It is equipped with

The end of each cigarette 3 opposite the filter 24 is fitted inside a holder 27 which is arranged coaxially with respect to the seat 4 and is connected to a gear 28. Each gear 28 rotates around its own axis as the tobacco 3 is conveyed forward by the drum 5.
It meshes with a ring 29 which is designed to rotate against.

The relationship between the speeds of the drum 5 and the cylindrical body 10 during operation is such that when the movable unit 22 makes one rotation around its own axis, the drum 5 moves the cigarettes by one step corresponding to the distance between two adjacent cigarettes 3. It is adapted to rotate around an axis 9 so as to move the robot 3 forward. Furthermore, if n is the number of holes 2 to be perforated in each cigarette 3, then the cigarettes 3 are cut through a perforation arc of length n steps (usually from the point of contact with the tobacco inlet drum of drum 5 to the tobacco inlet drum of drum 5). While being advanced by the drum 5 over a circular arc up to the point of contact with the delivery drum, the drive hand stages 27, 2
8 and 29, the tobacco is rotated one complete revolution around its own axis, during which time the tobacco is perforated. In order to drill n holes in each cigarette 3, the drilling arc must be at least n steps long, ie at least n cigarettes 3 are present simultaneously over the drilling arc. Also, the driving means 27, 2
8, 29 are such that when the drum 5 advances each cigarette 3 by one step, each cigarette 3 is rotated about its own axis by an angle equal to 360°/n. Similarly, the reflecting member 23 comprises n mirrors 25 arranged around an arc having a central angle that coincides with the central angle of the perforation arc.

In the operating mode described above, the movable unit 22
For each complete revolution around its own axis, the drilling device 1
makes one hole 2 in each cigarette 3 arranged on the perforation arc, so that each cigarette 3 exiting the perforation arc consists of n holes 2 equally distributed around the outer circumference of the filter 24. The ring is perforated.

In order to understand how the drilling device 1 works,
According to the known laws of physics, if a beam of light is focused by a focusing device on a spatially stationary point, no matter what trajectory the focusing device moves along, then
It should be pointed out that this deflection of the focused beam results in a new focal point, which, like the original focal point, becomes spatially stationary with changes in the position of the focusing device. Looking at the device 1 based on this principle, if we consider that if there is no mirror 25, the beam 7 will always be focused on the fixed point 19, then by inserting the mirror 25 the beam 7 will be focused on the point 26. , it is held stationary while the beam 7 scans its mirror 25 and is rapidly switched onto the surface of the next cigarette as the beam 7 begins to scan the new mirror 25. As a result, the beam 7 is "pulsated" by the group of mirrors 25, which repeatedly and periodically focuses the beam 7 on n points distributed at fixed positions relative to each other around the drilling arc. It brings about the effect of

At each of these points, the device 1 punches a hole 2 in the surface of the cigarette 3 at a time corresponding to the position of the point.

As the tobacco is conveyed through the perforation arc, each tobacco moves through all the points mentioned above, so that by the time the tobacco reaches the exit end of the perforation arc, a total of n holes 2 have been drilled into it. It will be done.

Furthermore, since each cigarette 3 rotates once completely at a constant speed when passing through the perforation arc, the hole 2
evenly distributed around the .

When irradiated by the focused beam 7, the tobacco 3 is continuously moving on the drum 5, so that the hole 2 usually has an oval shape. To rectify this drawback, a mirror 17 and a lens 2 are arranged so that the focus of the beam 7 moves with the cigarette 3 while each hole 2 is drilled.
0 with the optical axis, if there is no mirror 25, focus 3
0 occurs at a predetermined distance from axis 9.

That is, if the focal point fixed at the fixed point 19 (referred to as the first focal point) remains fixed in space regardless of the movement of the movable unit 22, the reflected focal point 26 will remain fixed; Since the perforated tobacco 3 rotates around its own axis and around the axis 9, each perforated hole becomes elliptical. In order to avoid such an oval hole, the angle between the mirror 17 and the optical axis of the lens 20 is modified, the first focal point is moved from the fixed point 19 to a new first focal point 30, and this focal point 30 is drilled. A point on the surface of the cigarette 3 is moved at the same speed along one circular arc.

As the movable unit 22 rotates, the focal point 30 does not stay spatially stationary like the focal point 19, but rotates on a circumference centered on the axis 9. Similarly, the reflective focal point 26 moves through space, and while the focused beam 7 scans any one of the mirrors 25, the focal point 36 moves through space.
traces an arc with a speed substantially proportional to the radius of the circumference around which it moves. By calculating this radius, we can therefore move the reflection focus 26 along the cigarette 3 while it is being pierced for each mirror 25;
It is possible to provide a completely circular arc 2.

[Brief explanation of drawings]

FIG. 1 shows a perspective view of a preferred embodiment of the drilling device of the present invention, and FIG. 2 shows a side view of the device of FIG. 1...perforation device, 2...ventilation hole, 3...cigarette, 5...
Drum, 6...Laser source, 7...Laser beam, 9...
Central axis, 10... Cylindrical body, 20... Lens, 22... Movable unit, 23... Reflection member, 25... Mirror.

Claims (1)

[Claims] 1. A laser beam for perforating ventilation holes in the tobacco 3 carried on a supply drum 5 which rotates about a first axis and which rotates relative to said drum about a second axis from itself. perforation device 1 comprising a laser source 6 and an optical reflection and focusing system designed to divert the beam emitted by the laser source 6 and focus it on a specific point on the surface of each cigarette 3; , the laser source 6 is designed to emit a continuous beam 7 along the first axis 9, and the optical system rotates about the first axis 9 to direct the beam 7 towards the first axis 9. a movable unit 22 designed to deflect and a ring arranged around said first axis 9 and designed to successively receive said beam 7 and deflect it outwards onto said tobacco 3; A drilling device characterized in that it comprises a fixed reflecting member 23 having a group of mirrors 25 shaped like the above. 2 The movable unit 22 has two mirrors 16 and 17
, one is provided on the first axis 9 and the beam 7
and the other is designed to receive the beam 7 reflected by the former and deflect it towards the first axis 9, and the movable unit 22 is designed to deflect the condensing lens 20. A device as claimed in claim 1, characterized in that it comprises: 3. The device according to claim 2, wherein the condenser lens 20 is disposed between the second mirror 17 and the reflective member 23. 4 When the second mirror 17 and the optical axis of the lens 20 are aligned, a focal point 30 is formed at a predetermined distance from the first axis 9 when the reflecting member 23 is not present, and this, together with the movable unit 22, 4. A device as claimed in claim 2 or 3, characterized in that it is arranged to rotate about an axis.