SU1750943A1 - Device for cutting paper sheet piles - Google Patents

Abstract

Use: cutting of paper sheets in the printing industry. SUMMARY OF THE INVENTION: The device comprises a conveyor with grippers for clamping the products to be processed, a knife, a vibration drive of a knife movement, and a balance weight of which is equal to the weight of the knife. Two cranks are mounted diametrically opposed to each other on the drive shaft and are connected by means of connecting rods to the knife and balance bar. Both the knife and the balance bar are mounted on the base each by means of a pair of equal and parallel rocker arms mounted in between, located in their middle position at an angle of 90 ° C. to the line of the cutting edge of the knife. The knife is provided with a spring damper in its final positions. 1 Cpfla, 1 Il.

Description

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The invention relates to the printing industry, namely to bookbinding and binding equipment, to paper cutting machines.

A device is known for cutting paper sheets that contains a base, a conveyor with grippers for clamping workpieces, a knife mounted on the path of movement of the conveyor hooks, the cutting edge of which is formed by two edges and placed at an acute angle to the direction of movement of the grippers, however, one of the edges forming the cutting edge is aligned with the cutting plane. In this device, the movement of the knife is vibrated in the same direction as the linear movement of the sheets of paper sheets, and an electromagnetic vibrator is used as the drive for moving the knife.

However, the principle of cutting by the cutting method, applied in the known device, imposes restrictions on the cutting speed, does not allow to obtain a stable cleanness of the cut surface and requires the use of a high-power vibration exciter. In addition, a vibrator with an electromagnetic excitation principle of high-power oscillations cannot function for a long period of time due to its small working life.

The purpose of the invention is to increase the durability, improve the quality of the products and increase the cutting speed.

The goal is achieved by the fact that in a device for cutting paper sheets containing a base, a conveyor with grippers for clamping workpieces, a knife is installed in the path of movement of the grippers of the conveyor, the cutting edge of which is formed by two edges and is placed at an acute angle to the direction of the slider VI O

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The grippers, and the vibrodrive for moving the knife, while one of the edges forming the cutting edge is aligned with the cutting plane, the vibrodrive for moving the knife is made in the form of a drive shaft, a balancer whose mass is equal to the mass of the knife, two cranks mounted on the tripping shaft is one diametrically opposed to another and connected by means of connecting rods with a knife and a balance bar, in this case both the knife and the balance bar are mounted on the base each by means of a pair of equally large and parallel rockers set between them e ennyh its middle position at an angle of 90 ° to the line of the knife cutting edge. In addition, the device has a spring-loaded shock absorber for the knife in its end positions, the vibration drive of the knife movement contains a flywheel mounted on the drive shaft, and the guide - counter-blade has a figured groove into which the knife enters.

The drawing shows a kinematic diagram of a device for cutting a stack of paper sheets.,

A device for cutting a stop of paper sheets contains a base 1, a conveyor with grippers 2 stop paper sheets (one grip is indicated), a knife 3 mounted on the base 1 by means of two equally sized rocker arms 4 and 5 installed parallel to each other and a vibration drive for moving the knife 3, as the drive shaft 6, the balance bar 7 mounted on the base 1 using two equally sized and in parallel mounted rockers 8 and 9, two cranks 10 and 11 mounted on the drive shaft b diametrically opposed to one Opposite and connected by connecting rods 12 and 13 with the knife 3 and the balance bar 7. Movement of the drive shaft 6 is transmitted from the electric motor 14 by means of a V-belt transmission 15. The cutting edge 16 of the knife 3 formed by two faces is positioned relative to the direction (arrow A) movement of the foot of paper sheets 17 at some acute angle o. The optimum values of which, depending on the thickness of the foot of the paper sheets, are in the range of 2 to 5 ° C, and one of the faces forming the cutting edge 16 is aligned with the cutting plane.

The knife 3 and the balance weight 7 are mounted on the base 1, each by means of a pair of equally large and in parallel mounted rocker arms 4,5,8,9, located in their middle position at an angle of 90 ° to the line of the cutting edge of the knife 3.

In order to smooth the sand loads in the vibrodrive of moving the knife, the flywheel 18 is mounted on the drive shaft b, the rollers 19 and 20 are fixed on the knife 3, which come into contact in the final positions of the knife with spring shock absorbers 21 and 22.

In addition, the device comprises a guide, an anti-cutter 23, used as a support for the cut foot of paper sheets.

In the guide - opposite to the blade 23 there is a shaped groove in which the knife goes in, which is necessary for reliable cutting of the foot, which, in turn, improves the quality of the products obtained.

The device works as follows.

Clamped in the clips 2, the stacks of paper sheets 17, moves at a constant speed and, upon its movement, hits a constantly vibrating one, for example at a frequency of 50 Hz, the knife 3, the movements of which are carried out practically along its cutting edge. This movement of the knife is ensured by the fact that the length of the rocker arms 4 and 5 is chosen much longer than the radius of the crank 10. For example, in the current installation, with a radius of 2.5 mm cranks and a rocker arm length of 50 mm, the deflection of the knife’s curved trajectory was only 0.06 mm, those. such a value that can be ignored

Another condition for ensuring the straightness of movement of the knife is to position the rocker arms 4 and 5 in the middle position of the knife at an angle of 90 ° to the line of the cutting edge 16 of the knife 3.

Due to the fact that the movement of the knife is actually done along the line of its cutting edge, the cutting of paper sheets that run into it at an acute angle is not done as in the prototype by chopping, but by re-shaping, which allows to obtain a clean cut with relatively small cutting forces.

When cutting a stack of paper sheets 17, it is supported by a guide - a counter-blade 23, which excludes the possibility of bending the sheets (especially the latter) under the influence of the cutting force.

Simultaneously with the reciprocating movement of the knife 3, in opposite phase with it, the second crank pair 11 and 13 move the balance bar 7, which due to the equality of its mass to the knife mass creates equal opposing dynamic loads on the drive, and thereby extinguishes the resulting Frequency of movement of scissors Use of balancer in

drive the knife allows you to increase the frequency of oscillation of the knife and, as a consequence, increase the cutting speed and quality of the products.

The absence of perceptible vibration in the actuator of the knife movement significantly increases its durability, i.e. term of service

Flywheel 18. smoothing typical loads in the vibratory drive of the knife movement, contributes to a smoother operation of the mechanisms of the device, which reduces the wear of movable joints and positively affects the quality of the resulting products.

Spring dampers 21 and 22, with which the knife interacts through the rollers 19 and 20, unload the vibrating actuator to move the knife to the extreme positions of the knife, helping in one case to slow down the moving mass, and in another case to accelerate it after stopping. The use of spring shock absorbers helps to increase the durability of the device.

Claims (2)

1. A device for cutting a stack of paper sheets, comprising a base, a support, a conveyor with grippers for clamping workpieces, a knife mounted in the path of movement of the grippers of the vehicle "23 The ra, cutting edge of which is formed by two faces and placed at an acute angle to the direction of movement of the claws, and the vibrating wire of moving the knife, when this one of the edges forming the cutting edge, is aligned with the cutting plane, characterized in that, in order to increase durability and increase the quality of the products obtained by increasing the cutting speed, the vibration of the movement of the knife is made in the form of a drive shaft, a balancer whose mass is equal to the weight of the knife, two cranks mounted on the drive shaft diametrically oppositely to one another and linked via connecting rods to a knife and the balance, with both the knife and the balancer are mounted under each by a pair of equal and parallel mounted between a rocker arm disposed in its middle position at 90 ° to the line of the knife cutting edge. 2. Pop-1 device, characterized in that the knife is provided with shock absorbers installed in its end positions, the vibration drive of the knife movement is equipped with a flywheel mounted on the drive shaft, and the support is made with a figured groove under the knife.