FI78947C - MEKANISK AVSKAERNINGSANORDNING FOER PAPPERSBANA. - Google Patents

Description

78947 1 Mechanical paper cutter

The invention relates to a mechanical cutting device for a paper web.

It is known in the art to use a pressurized water jet to cut a paper web. However, the drier the web, the harder it is to break it by filling it with a jet of water.

A new paper web cutting device with a cutting blade corresponding to the width of the paper web is again known from FI patent application 810378. Said cutting blade is movable transversely to its longitudinal direction between the support rollers to the cutting position and can be further retracted 15 to its initial position. This cutting blade is further movable so that it is guided at its ends by side guides. The cutting blade has a serrated or knurled cutting section. In this solution, the ends of the cutting blade are attached to levers rotatable about the axis of the second support roller. In this solution, the blade structure is very heavy 20 and difficult to adjust.

Pneumatic cutting pipes are also known from the prior art. With the help of air jets, the edge strip is pulled in opposite directions in the area of the guide plates, whereby the edge strip breaks by tearing the connection between the guide plates or at the nozzle openings.

The object of the invention is to provide a paper web cutting device with which the paper web can be cut quickly and accurately over the entire width of the paper web. The aim is also to have a cutting device in which the blade-30 part does not collect water or dirt. The aim is also to have a cutting device which does not require large amounts of air or water, as is the case when using cutting pipes.

The object of the invention has been achieved by a device solution, which is mainly characterized in that the cutting edge of the paper web is a wire.

2 78947 Ί The device solution according to the invention comprises pivot lever mechanisms articulated to the shaft ends inside the shaft bearings. At least a second pivoting lever mechanism is adapted to pivot an actuator, preferably a cylinder device. By moving the piston rod of the cylinder, preferably the pneumatic cylinder, the pivoting lever mechanism is moved. According to the invention, a tensioning device for cutting a web of paper cutting the entire width of the paper web is further connected to the pivoting lever mechanisms arranged at the ends of the shaft. The tensioning device comprises at least one spring. The spring is connected between the pivot lever mechanism 10 and the pin securing the wire connected to the pivot lever mechanism.

The spring maintains a certain tension in the wire under all operating conditions.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figure 1 shows a cutting device according to the invention in a side view.

Fig. 2 is a partial view of a cutting device according to the invention taken along the section line I-I in Fig. 1.

Figure 3 shows a second embodiment of the invention corresponding to Figure 2.

Figure 1 shows a paper web cutting device 10 according to the invention. The paper web is guided from a first roll, preferably a central roll 11, to a second roll 12 with a cutting mechanism and further to a third roll 13. The directions of rotation of rolls 11, 12 and 13 are indicated by arrows.

30

The scraper 14 is adapted to guide the cut paper web Vf to the pulper 15. After cutting, the end of the web thus continues to the pulper 15 and the tail, i.e. the web part preceding the cutting point, continues to the next point of interference.

The paper web cutting device 10 according to the invention further comprises a blade 20 pivot lever mechanism 16 comprising a first shank portion 16a and a second shank portion 16b associated therewith, preferably at a 90 ° angle.

The second arm portion 16b is further associated with a third arm portion 16c parallel to the central axis of the shaft 12, in which the cylinder 17 is mounted at the end of the cylinder arm 17a by a bearing 18. Cylinder 17 is preferably a pneumatic cylinder. The pivot lever mechanism 16 further comprises a bearing 19.

The curved bearing portion 19a is connected to the other end of the first arm portion 16a and comprises a medicament surface adapted to slide against the counter bearing surface of the roll 12. Said bearing 19 is arranged inside the bearings 25a and 25b of the roll 12.

Thus, as shown by the arrow in Fig. 1, the blade 20 can be moved by means of the cylinder device 17 from the position indicated in Fig. 1 to the position B 1 shown in broken lines. The curved movement of the blade 20, being a thin wire according to the invention, is indicated by the arrow L 1. The blade 20 cuts the paper web W at point C.

15

According to the invention, 20 wires are used as the blade, preferably a wire and more preferably a steel wire. The tension of the wire 20 is adjustable by the breaking wire tensioning device 21.

According to the invention, the cutting wire tensioning device 21 comprises a pin 22 passed through a bore in the shank portion 16a. The pin 22 moves freely in said borehole and between the end flange 23 of the pin 22 and the bearing surface 25a 'on the bearing side 25 of the shaft part 16a and a spring 24, preferably a compression spring, is placed around the shaft 22a of the pin 22.

25

The wire 20 is attached to the pin 22. By means of the spring 24, the tension of the wire 20 remains constantly unchanged despite the possible elongation of the wire 20 due to the load. By changing the springs 24, the desired tension can be adjusted. It is also possible to provide a pin 22, 20 which is adjustable in length, whereby the tightening force can also be adjusted steplessly.

When it is desired to cut the web, the pivot lever mechanisms 16 with the wire 20 attached to them are turned to the lower position, whereby the wire 20 cuts 25 across the web W over the entire width of the web. The end of the track W continues to the pulper 15 and the web part preceding the tail, i.e. the cutting point, continues to the next point of interference 78947. When the track W is broken, the cutting wire 20, preferably the wire, can be returned to the upper position without hindrance.

With the device according to the invention, a fast and accurate circuit breaker is achieved. The yarn according to the invention does not collect water or dirt due to the small cross-section of the part passing through the machine. The cross-section of the wire 20 acting as a blade is preferably about 4 mm. Also, large amounts of air and water are not required, as is the case with chimney pipes. The movement of the track W also enhances the cutting event. The device according to the invention 10 is also not in the way during the head export phase.

Figure 2 shows a device solution in which both ends of the shaft 12 comprise similar pivoting lever mechanisms and their pivoting devices. The cutting wire 20 is fitted between the pins 22 connected to the pivoting lever mechanisms 15 at the ends of the shaft 12. Of course, within the scope of the invention, an embodiment is also possible in which the tensioning device of the wire 20 is arranged only in the second pivoting lever mechanism and in which the second pivoting lever mechanism does not comprise such a tensioning device.

20

The cutting of the paper web with the device according to the invention comes into question primarily after the press part, because the web is then not very strong. Alternatively, the device according to the invention can be operated with an adhesive press connected to the drying section. The invention can also be applied at the end of the drying section.

Fig. 3 shows a second embodiment of the invention corresponding to Fig. 2, in which only an actuator, preferably a cylinder, adapted to pivot the pivot lever mechanism 30 and thus the cutting wire 20 is connected to the second pivot lever mechanism 16. with an intermediate portion 26. Said intermediate portion 26 synchronizes the pivot lever mechanisms to pivot simultaneously. This intermediate part 26 also makes it possible to omit the second cylinder 17 or some other similar actuating device 35 at the second pivoting lever mechanism.

Il

Claims (4)

5,78947 Ί Claims A mechanical paper cutting device (10) comprising actuators arranged in the vicinity of the bearings (25a, 25b) of the roll (12), preferably pivoting lever mechanisms (16) adapted to pivot by means of a cylinder (17), between which a blade cutting the entire width of the paper web is placed, characterized in that the cutting edge of the paper web is a wire (20), preferably a wire. Cutting device according to Claim 1, characterized in that the cutting device comprises a tensioning device (21) for the wire (20). Cutting device according to Claim 2, characterized in that the tensioning device (21) comprises a spring (24) by means of which the tension of the wire (20) can be kept constant. Cutting device according to the preceding claim, characterized in that the tensioning device (21) comprises a pin (22) operatively connected to the pivoting lever mechanism (16) of the wire (20), to which the wire (20) is attached, each pin (22) is adapted to move relative to the pivoting lever mechanism (16) and that there is a spring (24) arranged between the end flange (23) of the pin (22) and the bearing surface (16a ') on the bearing (25a) side of the first arm portion (16a), and that the wire (20) is then tightened between the pivoting lever mechanisms (16) at the ends of the roll (12), the spring (24) maintaining the tension of the wire (20). 30 35