CH678158A5 - - Google Patents

Description

1

CH 678 158 A5

2nd

description

The invention relates to a device for removing the section strips when trimming a book * or stack of brochures on three-knife cutting machines by means of air.

When trimming books or brochures on three-knife cutting machines, in which a front knife and side knife cut against a cutting bar, the section strips that occur when the material to be cut is cut by the front knife or by the side knives must be removed from the conveying plane of the Cuttings to be removed.

Solutions are known in which an attempt is made to remove the section strips by means of bias air which emerges from a nozzle and is in movement connection with the knife carrier.

In another solution, a mechanically movable separating wedge is arranged on the knife carrier in addition to this blowing air nozzle. The separating wedge is held under spring force in a position upstream of the knife cutting edge, at a defined distance, and pushed back against the spring force until it rests against the knife calf during the cutting process. In this phase it is like a rigid wedge.

The separating wedge is moved with the knife return movement under contact with the separated section strip over a small distance in the longitudinal direction of the cutting edge, so that the tensile component acting in the longitudinal direction of the section strips separates the lowest section strips, but due to the simultaneous reduction in the time available for section disposal until Subsequent cycle no residue-free section removal from the funding level is achieved.

For all of the above Solutions, however, no optimal swirling and residue-free section covering from the conveying plane of the material to be cut is achieved.

The section strips that have not been removed are entrained by the following book block and can cause contact errors on the back stops, which leads to a reduction in quality or get into subsequent machine units and cause production interruptions.

The aim of the invention is to design a device for removing the cut strips when trimming a stack of books or brochures on three-knife cutting machines by means of blowing air in such a way that the cut quality, the effective availability and the work productivity are further improved in use.

The object of the invention is to provide a device for removing the section strips when trimming a stack of books or brochures on three-knife cutting machines by means of blown air, with which swirl-free and residue-free section strip removal is achieved by means of air from the conveying plane, so that after the side knife and Front knife average following next insertion of a new book or brochure stack into the cutting station is guaranteed trouble-free.

According to the invention, the object is achieved on a device for removing the section strips when trimming a stack of books or brochures on three-knife cutting machines by means of air in that at least one outlet nozzle is arranged at an angle to the working surface of the cutting table in a cutting table directly behind a cutting support, the outlet nozzle being above a blown air line, a further line and a directional valve are connected to an air supply system and can be acted upon by air in a cycle which corresponds to a working rhythm of the cutting knives.

The use of the device according to the invention ensures that the section strips obtained during the cutting process are optimally separated from the knives and the cutting supports. In connection with the known blow air nozzles, which are arranged on the knife carriers, blow down and the flow of the suction system, a swirling and residue-free section removal is realized.

The complete removal of the section strips ensures an absolutely true-to-size trimming on three sides with a simultaneous increase in performance.

The invention will be explained in more detail below using an exemplary embodiment.

The accompanying drawings show;

Fig. 1: the schematic representation of a side view of the inventive device, wherein the knife shown is in the average position

Fig. 2: the schematic representation according to Fig. 1, wherein the knife shown is at the beginning of the knife rise

1 shows a cutting table 2 with a cutting support 7, on which a stack of books or brochures, hereinafter referred to as stack of cut goods 1, is lying and a knife carrier 4 carrying a knife 3, to which a blowing air nozzle 5 is assigned in a known manner . Above the cutting table 2 there is a press ram 6 seated on the stack of material 1 to be cut.

Immediately behind the cutting support 7, outlet nozzles are arranged in the cutting table 2 obliquely to its support surface, parallel along the knife edge. The outlet nozzles 8 are connected to an air supply system 13 via a blown air line 9, a throttle valve 10, a line 11 and a directional valve 12.

The throttle valve 10 throttles the flow rate of the air in accordance with the paper quality and the mass of the material to be cut 1. The duration of action of the flow rate of the air at the outlet nozzle 8 is determined by the directional control valve 12 in accordance with the working rhythm of the three-knife cutting machine.

In the vicinity of the cutting table 2 there is a high-performance three-knife cutting machine

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

3rd

CH 678158 A5

4th

NEN an extraction system 14 with a constantly acting air flow 15 for forwarding the section strips into a central chip storage. The case of cut strips is ensured by a cutting bridge 16, which is controlled in time with the machine. The directional control valve 12 is switched almost simultaneously, so that a pressure builds up in the line 11 and in the blown air line 9 as a result of the outlet nozzle 8 being closed by the stack of cut material 1, which is pressed onto the cutting table 2 by the press ram 6.

At the beginning of the cutting process by the knife 3 shown, the blowing air nozzle 5 begins to blow, the upper section strips 19 becoming mechanically caused by the knife wedge itself and by the blowing air nozzle 5 blowing on the knife edge, downwards in operative connection with the suction of the feed stream 15 the suction system 14 blown into a suction container, not shown.

After the knife average, the knife 3 returns to its starting position and the press ram 6 detaches from the stack of cut material 1. When the knife starts to rise and the pressure is released, the stack of cut material 1 is raised by the air outlet from the outlet nozzle 8, which is still on the cutting support 7 remaining section strips 19 are released from the cutting material support 7 by escaping air and blown in the direction of the downward air flow 20 of the blowing air nozzle 5.

In connection with the conveying flow 15 of the suction system 14, the section strips are removed without swirling and without residues

19 and T§.

After a blowing time that corresponds approximately to a crank angle of 15-20 ° of the single-turn shaft, the directional control valve 12 is switched over and the air outlet from the outlet nozzle 8 of the cutting table 2 is thus prevented.

The feed level 17 is free of chips for the next stack, the cutting material bridge 16 is lowered into the horizontal position as the next stack approaches - the trimmed stack of cutting material is pushed out in parallel. A quality-appropriate system on the back stop, not shown, is guaranteed for the following stape 18.

Claims (2)

Claims 1. Device for removing the section strips when trimming a stack of books or brochures on three-knife cutting machines by means of air, characterized in that in a cutting table (2) immediately behind a cutting support (7), at least one outlet nozzle (8) is arranged at an angle to the contact surface of the cutting table The outlet nozzle is connected to an air supply system via a blown air line (9), a further line (11) and a directional control valve (12) and can be acted upon with air in a cycle which corresponds to a working rhythm of the cutting knives. 2. Device according to claim 1, characterized in that a throttle valve (10) is arranged between the blown air line (9) and the further line (11). 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 3rd