DE3116468A1 - Finger guard on belt knife machines - Google Patents

Abstract

The device according to the invention is a guard device on belt knife machines, which operate independently of human volition and makes injuries caused by the rotating knife impossible. This guard device is composed of a guard basket which is raised and lowered by means of a pneumatically controlled piston and receives all the necessary control pulses via a special electronic control device. Electronic auxiliary control devices and switches ensure that the guard basket is in each case only raised or lowered until there is no gap between the layer of material to be cut and the guard basket, thereby making injuries to fingers impossible. Apart from the electronic control device, which comprises a sensing switch, a light barrier with a light barrier amplifier, electronic switches, switching amplifiers and pulse delay switches, the device according to the invention also includes a pneumatic control device, which comprises solenoid valves, flow control valves and pipes.

Description

Finger protection on band knife machines

Field of the Invention The invention relates to an automatic Working protective device on band knife machines in the area of cutting the Clothing and lingerie industry.

Characteristics of the known technical solutions There are finger protection devices Known on band knife machines in the lonfection industry, in which a plexiglass washer or a metal grid is attached in front of the vertically rotating band knife. These Finger protection devices are individually placed in front of the rotating by the operator Band knife lowered or angled. In this case, the operator must use the singing protection device adjusted according to the respective layer height.

The disadvantage of these simple mechanical protective devices is there in that these devices are individually used by the operator in each case layer height that changes with the work rhythm must be set, whereby this often omitted due to lack of time.

These finger protection devices do not work independently of will of the operator and for this reason are fundamentally due to health and safety reasons insufficient.

Furthermore, an electromechanical finger protection device is known in which a protective basket acts independently of the will of the operator on the one to be processed The fabric layer is lowered 0 The knife cover is adjusted to the respective layer height by means of Pull magnets adapted over pulleys and ropes. The upward movement is triggered with; tcln light barrier and push button. The first electromagnet tears the protective cage in the highest position, after which the Protective cage on the upper fabric layer falls back and then by the second electromagnet briefly over the top layer of fabric is raised to a defined distance. After finishing the cutting process the protective cage falls back into its lowest starting position. This finger protection device is fundamentally inadequate because it has too many deficiencies and one optimal use not guaranteed. The shortcomings of this finger protection device are as follows: The mode of operation of the electromagnet brings about a strong and sudden Noise generation.

The susceptibility of this device is very great, because the ropes stretch and often tear due to the sudden load.

The pulling magnets hit hard and often break of the filament of the lightbulb of the light barrier and thus to the total failure of the Protective device Furthermore, the protective device has an inadequate electromechanical one Control, which leads to frequent incorrect switching, so that they are in the upper End position stuck.

Due to these deficiencies, a high maintenance and care effort is required necessary.

According to DU-PS 2227184 and DT-OS 2625472 and 2625473 are protective circuits known for band knife cutting machines, which only work when the rotating Band knife by the operator in connection with an emergency braking to stop of the cutting machine 0 The knives of the devices described are not covered. The after-run of the knife after the emergency stop has taken place is to 1/1000 of a second, this can cause a cut at the appropriate speed of 2 to 3 cm.

Object of the invention The object of the invention is to provide a maintenance-free, Low-noise finger protection device that works independently of the will of the operator to develop.

Statement of the essence of the invention The technical task of the invention consists in a structurally simple, electronically controlled, mechanical and Technologically adaptable and functionally reliable finger protection device for To develop band knife machines.

This object is achieved by the protective device according to the invention such as follows solved: On the upper part of a band knife machine is behind the endless knife a bracket for receiving a working cylinder attached. On this bracket is a working cylinder that has a finger guard in extension of its piston rod is grown. A sensor is located on the lower sole of the finger protection, which corresponds to a sensor switch. Half the length of the piston rod is a switch plate is attached, which is fitted with a limit switch cooperates.

There are feed hoses on the upper and lower parts of the working cylinder downstream with appropriate pneumatic control organs, which by appropriate Functional electronic control units can be switched on and off and thus effect the overall function of the finger protection device. The electronic control unit consists of a light barrier that is directly connected to a light barrier amplifier, a first electronic switch, a switching amplifier and a solenoid valve follow, which from a sensor switch via the third electronic switch and the second pulse delay switch receives the final pulse, whereby the light barrier amplifier in addition to the first electronic switch, also the first pulse delay switch influenced. The first pulse delay switch in turn affects a second electronic switch, the other hand on a third electronic switch reacts back, the limit switch also acting on the aforementioned second electronic switch acts and here the output of the first pulse delay switch even to the third electronic switch, the same from the second electronic switch is affected and the third electronic switch controls, which is followed by a second switching amplifier and a solenoid valve. Simultaneously acts; the third electronic switch on the second pulse delay switch, which in turn affects the first switching amplifier.

In operation, the finger guards work as follows: The The operator enters the area on a pad lying on a tabletop the light barrier pushed.

When the light barrier is interrupted, an impulse becomes a Light barrier amplifier given. This impulse is about the first electronic Switch (interlock) routed to the switching amplifier and solenoid valve. The solenoid valve opens, and through a throttle valve, compressed air is fed through a line into the Working cylinder for rapid upward movement of the piston rod with finger protection pressed.

The piston rod slides; in the upper end position, actuating the The switch cam on the piston rod controls the limit switch. This gives an impulse to a second electronic switch, which is the first electronic switch controls and thus switches off the upward movement of the piston rod, at the same time the piston is vented and locked. The second also controls the electronic Switch on a subsequent third electronic switch in order to have a pulse delay and a switching amplifier to open a solenoid valve. Via a subsequent throttle valve compressed air is passed through a line to the working cylinder. This will make the Piston with finger guard lowered to the fabric layer. When putting on the finger protection On the fabric layer, the sensor switch sends an impulse to a third electronic one Switch given which switches off the solenoid valve and via a pulse delay and a switching amplifier briefly opens the solenoid valve. It succeeds; one Defined upward movement of the piston rod and the finger protection. So is the finger protection is in the working position above the layer of fabric, and the operator can perform the cutting. After the cutting is finished the light barrier opens again and sends an impulse to the light barrier amplifier.

Via a pulse delay and the second electronic switch is unlocked and at the same time a solenoid valve is opened via the switching amplifier. Compressed air is supplied to the working cylinder through a throttle valve and a line, and the piston with the finger protection slides into its lower end position. The finger protection device is now back in its original position.

Exemplary embodiment The invention is illustrated below using an exemplary embodiment 1 and 2 explained in more detail: On a rail-shaped bracket 1 is a Working cylinder 2 attached. A piston rod 3 of the working cylinder 2 £ imnt am a finger guard 4 on the lower end. In the socket of the finger guard 4 is; a Sensing switch 5 arranged.

in switching cam 6 is attached to the piston rod 3.

A limit switch 7 is arranged next to the piston rod 3. Direct In front of the finger protection 4, a light barrier 9 is inserted in a work table 8. An electronic control device 10 is attached below the work table 8. In this control unit 10 are a light barrier amplifier 11, an electronic one Switch 12 for locking, a switching amplifier 13, a pulse delay switch 14, an electronic switch 15 for reversing, another pulse delay switch 16, an electronic switch 17 and a switching amplifier 18 correspondingly arranged. Solenoid valves 19 are provided for the efficient supply of the working cylinder 2 and 21, provided with throttle valves 20 and 22 and lines 23 and 24, are attached.

The technological process is as follows: The one on a work table 8 lying layer of fabric (not shown here) is placed in the Area of Light barrier 9 pushed. By interrupting the Lich-W-barrier 9, a pulse is given to the light barrier amplifier 11. This becomes via the electronic switch 12 to the switching amplifier 13 and solenoid valve 19 headed.

The solenoid valve 19 opens such, and through the throttle valve 20 is Compressed air via a line 23 into the working cylinder 2 for rapid upward movement its piston rod 3 with finger protection 4 guided. The piston rod 3 slides in the upper end position, while a switch actuates cam 6 on the piston rod 3 the Limit switch 7. This gives an impulse to the electronic switch 15, which controls the electronic switch 12 and sen lt the upward movement the piston rod 3 switches off, at the same time the working cylinder 2 is vented and locked, the electronic switch 15 controls the electronic switch 17 to over the pulse delay and the Sehe ltver stronger 18 the solenoid valve 21 to control.

The solenoid valve 21 is opened, and the throttle valve 22 is Compressed air is passed through line 24 to working cylinder 2. By loading of the working cylinder 2, the piston rod 3 with the finger guard 4 becomes the bottom position moved downwards. When the sensor switch 5 is placed on the fabric, an impulse is generated given to the electronic switch 17, which switches off the solenoid valve 21 and the solenoid valve via the pulse delay switch 16 and Jan switching amplifier 13 19 opens briefly.

A defined upward movement of the roller rod 3 also takes place Fingerschu-Uz 4. Thus, the working position of the finger protection 4 is above the layer of fabric reached, and the operator can perform the cutting. After finishing the When the blank is cut, the light barrier 9 is released and sends a pulse to the light barrier amplifier 11 via the pulse delay switch 14 to the electronic switch 17. This Impulse unlocks the electronic switch 12, and at the same time the solenoid valve 21 opened via the switching amplifier 18. By applying the line 24 are the working cylinder 2 and the piston rod 3 with finger protection 4 moves down to its lower end position. The finger guard 4 is now back in its starting position.

The advantages of the inventive solution consist in a functionally reliable, regardless of the operator's wish to work ii; endcn finger protection device, which Maintenance-free, noiseless and low-wear in production. Through this For the first time, a protective device provides optimal work protection on band knife machines secured.

List of the reference symbols used 1 holder 2 working cylinder 3 Piston rod 4 Finger protection 5 Sensor switch 6 Switching cam 7 Limit switch 8 Work table 9 light barrier 10 electronic control unit 11 light barrier amplifier 12 electronic switch 13 switching amplifier 14 pulse delay switch 15 electronic switch 16 pulse delay switch 17 electronic switch 18 Switching amplifier 19 Solenoid valve 20 Throttle valve 21 Solenoid valve 22 Throttle valve 23 line 24 line

Claims (2)

He indungsanspr I 1. Finger protection device on band knife machines with a covered knife, characterized in that above a work table (8) in a holder (1) a working cylinder (2) and belonging to this a piston rod (3) with attached finger protection (4) with foot switch (5) and in the middle the piston rod (3) a switch cam (6) and one above it on the bracket (1) BeSes-saturated limit switch (7) are arranged and below the work table (8) an electronic control unit (10j and a pneumatic control device, consisting of solenoid valves (19; 21), throttle valves (20; 22) and lines (23; 24) are attached. 2. Finger protection device according to item 1, characterized in that that the electronic control unit (10) consists of a light chain amplifier (11), an electronic switch (12), a switching amplifier (13), a pulse delay switch (14), an electronic switch (15), a pulse delay switch (16), an electronic switch (17) and a switching amplifier (18) consists a light barrier (9) in direct connection of the light barrier amplifier (11), the electronic switch (12) with switching amplifier (13) and the solenoid valve (19) are downstream; via the limit switch (7) and the electronic switch (15) are both the electronic switch (12) and the electronic switch (17), the switching amplifier (18) and the solenoid valve (21) switched; the sensor switch (5) are once via the electronic switch (17), the pulse delay switch (16), the switching amplifier (13) with the solenoid valve (19) to the other via the switch (17) the switching amplifier (18), downstream of the solenoid valve (21), continue to be the light barrier (9) and the light barrier amplifier (11) the pulse delay switch (14), the electronic switch (17), the stronger switch (18) and the solenoid valve (21) or the light barrier (9) and the light barrier amplifier (11) of the pulse delay switch (14), the electronic switch (15) and before electronic switch (12) are connected downstream.