EP0732179A1 - Method and apparatus for cutting belts with reinforcing layers - Google Patents

Abstract

During the cutting action the belt material (38) is set between two clamping jaws and is seized on each side by the cutting edges (36,37) of the blade (17) which form an acute angle between them and are straight or curved convex towards the belt. The blade is passed through the belt material with a clearly vertical play whereby the blade centres automatically relative to the reinforcement insert enclosed in the belt. The two cutting edges of the blade can be symmetrical relative to each other to form together a V- shaped cutting notch.

Description

The invention relates to a method for cutting belts provided with reinforcing inserts, in particular for cutting conveyor belts from a reinforced elastomer, in which the belt is arranged between two clamping jaws, and for performing the cut, the clamping jaws with the belt arranged therebetween are pressed against one another, and at the same time, a knife is guided through the band material by means of a drive along the clamping jaws and transversely to the longitudinal direction of the band.

The invention further relates to a cutting device for belts provided with reinforcing inserts, in particular for conveyor belts made of a reinforced elastomer, with a clamping device comprising two clamping jaws arranged transversely to the belt and which can be pressed against one another with the interposition of the belt, and with a movable along the clamping device using a drive Knife with at least one cutting edge.

A method and a cutting device of the type mentioned are described in the French utility model certificate 2458497. An elastic band, which can be a fabric with rubber-coated threads, is separated into individual strips by a plurality of transverse cuts, the strips later being used to produce the carcass of a tire. For this purpose, the band used as raw material is clamped between two clamping jaws that can be pressed against each other, and then a horizontally movable knife is passed through the Tape material passed through. The tape material lies on a conveyor belt on rubber. In order to avoid that the conveyor belt is also cut by the knife, there is a rounded widening in the manner of a bead at the lower edge of the knife provided with two crescent-shaped cutting edges. During the cut, the bead partially presses the elastic conveyor belt down into a wide groove in the lower jaw, so that the conveyor belt is not damaged during the cut. The knife is rigidly attached to a carriage that runs exactly along the upper jaw. The cutting height of the knife is set so that the edge of the band to be cut slides along the top of the bead during the cut and thus in the transition between the bead and sickle-shaped knife edge.

The known cutting device can be used for cutting through fabrics and in particular also rubber-coated fabrics. On the other hand, it has proven to be unsuitable for severing conveyor belts designed for high loads and in particular conveyor belts reinforced with steel wires, such as those e.g. can be used to transport coal and overburden in surface and underground mining.

Conveyor belts that are reinforced by steel cables or wire mesh are currently still severed by hand because suitable machines and machine processes are not available. As a rule, the elastomer enclosing the reinforcement is first cut open from both sides in the form of a wedge that is as deep as possible. Subsequently, each individual steel wire is cut using a hand-held, commercially available cut-off machine. This work in particular, which requires at least three people to carry out, is extremely laborious and involves considerable noise and a high level of dust. While working with the cut-off machine, it is also impossible to prevent the rubber material from being caught by the cutting disc, which means that this work is also associated with the development of vapors and an unpleasant odor nuisance. A cut made in this conventional way takes between half an hour and an hour on a steel-reinforced conveyor belt of 2 m width. Such a period is at best to be accepted when it comes to cutting the tape once goes, for example for repair purposes. On the other hand, it is out of the question when it comes to cutting a worn-out conveyor belt into individual short sections for the purpose of disposal, as will be required in the future due to the increasingly strict environmental laws.

The invention has for its object to provide a cutting method with which all types of tapes provided with reinforcing inserts and in particular also tapes provided with steel reinforcements can be severed quickly and with a long service life of the cutting tool used. A cutting device suitable for this purpose is also to be created.

As a solution to the method, it is proposed that the strip material be gripped on both sides by cutting edges of the knife during the cut, which form an acute angle between them and are each straight or convexly curved towards the strip. The knife is preferably passed through the band material with a clear vertical play, the knife automatically centering with respect to the reinforcement insert enclosed in the band.

To solve this problem , a cutting device of the type mentioned at the outset is also proposed, in which the cutting edge is shaped straight or curved convexly towards the strip, a further cutting edge is arranged at an acute angle to the cutting edge, and the strip is between the two cutting edges during the cut located.

Due to the essentially V-shaped arrangement of the two interacting cutting edges, it is possible to cut even tapes provided with steel reinforcements unusually quickly and with a long service life of the knife edges. Cutting an approximately 2 m wide rubber band with steel cable reinforcement can be carried out in less than 2 minutes and is done without dust and with little noise. A supervisor may be required during the implementation of the procedure.

According to a preferred embodiment, both cutting edges of the cutting device are on the knife. Here, the two cutting edges can be designed symmetrically to one another, together forming the approximately V-shaped cutting notch. This shape of the cutting notch causes the knife to center itself with respect to the reinforcement insert enclosed in the band. The highest cutting force is therefore concentrated precisely where the highest material resistance has to be overcome, i.e. in the area of the reinforcement to be cut.

In order to enable the knife to center itself with respect to the reinforcement, the knife can have a clear play in the direction perpendicular to the flat sides of the band, whereas the knife should be essentially rigid in the longitudinal direction of the band.

The invention also proposes that the knife be arranged on a carriage that can be moved back and forth along the clamping device. In order to enable the knife to compensate for the desired play, the knife can be rigidly attached to the carriage, in which case the carriage is guided with clear vertical play on one of the two clamping jaws of the clamping device.

It has also proven to be advantageous if the tensile forces for moving the carriage act as close as possible to the knife edges. For this purpose, it is proposed with an embodiment of the invention that the carriage is provided on its long side facing away from the knife with support rollers which can run on guide surfaces of the clamping jaw receiving the carriage, and that traction means are provided for moving the carriage, which are at the level of the knife facing half of the car are attached to the car.

In order to prevent lateral deflection of the knife, the clamping jaw can be provided with a longitudinal slot through which the knife is passed. In this case, the knife can be guided entirely or partially through the longitudinal slot.

For the practical use of the cutting device in transport systems, it has proven to be advantageous if the clamping jaws can be pivoted relative to one another by means of a swivel joint, and the cutting device including the clamping jaws can be fully opened at its end facing away from the swivel joint, so that the band can be opened from the side to be able to slide between the open jaws. In this way it is possible to make cuts on the spot without disassembling the entire cutting device, e.g. on a conveyor belt in need of repair within a belt stand. To facilitate transport of the cutting device, the upper side of the cutting device can be provided with eyelets so that the cutting device as a whole can be lifted from a gantry crane or other conveying device and transported to the desired place of use or swung into a belt stand.

Fig. 1

in Frontansicht eine schematische Darstellung einer Schneidvorrichtung zum Durchtrennen eines durch Stahlseile armierten Elastomers;

Fig. 2

eine Draufsicht auf die Vorrichtung gemäß Fig. 1;

Fig. 3

eine perspektivische Darstellung der Vorrichtungen gemäß den Figuren 1 und 2, wobei ein Teil zur besseren Deutlichkeit als Ausbruch dargestellt ist;

Fig. 4

in einer Detaildarstellung einen Querschnitt in der Ebene IV-IV der Fig. 1;

Fig. 5

ein Detail der Fig. 4 in nochmals vergrößertem Maßstab;

Fig. 6

in einer Schnittdarstellung in der Ebene VI-VI der Fig. 5 die Ansicht eines Wagens mit daran befestigtem Messer;

Fig. 7

eine der Fig. 5 entsprechende Darstellung bei einer zweiten Ausführungsform der Schneidvorrichtung;

Fig. 8

eine der Fig. 6 entsprechende Darstellung bei der zweiten Ausführungsform der Schneidvorrichtung;

Fig. 9

eine der Fig. 3 entsprechende Darstellung bei einer dritten Ausführungsform der Schneidvorrichtung;

Fig. 10

ein Detail der Schneidvorrichtung nach Fig. 9;

Fig. 11

einen vergrößerten Querschnitt im Bereich des Messers durch eine Schneidvorrichtung und

Fig. 12

einen Schnitt in der Ebene XII-XII der Fig. 11.

Further properties and advantages are explained below using exemplary embodiments and with reference to the accompanying drawings. The drawings show:

Fig. 1

in front view, a schematic representation of a cutting device for cutting an elastomer reinforced by steel cables;

Fig. 2

a plan view of the device of FIG. 1;

Fig. 3

a perspective view of the devices according to Figures 1 and 2, wherein a part is shown for clarity as a breakout;

Fig. 4

in a detailed representation a cross section in the plane IV-IV of Fig. 1;

Fig. 5

a detail of Figure 4 on a further enlarged scale.

Fig. 6

in a sectional view in the plane VI-VI of Figure 5, the view of a carriage with a knife attached.

Fig. 7

a representation corresponding to Figure 5 in a second embodiment of the cutting device.

Fig. 8

a representation corresponding to Figure 6 in the second embodiment of the cutting device.

Fig. 9

a representation corresponding to Figure 3 in a third embodiment of the cutting device.

Fig. 10

a detail of the cutting device of FIG. 9;

Fig. 11

an enlarged cross section in the area of the knife through a cutting device and

Fig. 12

a section in the plane XII-XII of Fig. 11th

With reference to FIGS. 1 to 4, the device used to carry out the cutting process comprises a fixed substructure 1, on the outer ends of which two support brackets 2 are arranged. Opposite each other, two horizontal U-profiles 8 are arranged which, as shown in FIG. 4, form an upper clamping jaw 10 which forms a cavity on the inside, the two profiles of this clamping jaw 10 being firmly connected by brackets 9. A movable frame 1 'is mounted so that it can slide vertically on the base 1. The movable frame contains a pair of horizontal U-profiles 3, which are arranged opposite one another, and in this way form a lower troughed jaw 13. Two pairs of vertical supports 4 are arranged near the ends of this lower jaw 13 and are connected at the end face by a cross member 5. Furthermore, two horizontal longitudinal members 6 are provided, between which a plurality of rollers 7 arranged parallel to one another are mounted, in order in this way to form a horizontal supporting surface for the band to be cut. At the upper ends, the vertical supports 4 are connected in pairs by a strut 4 '. Each strut 4 'is supported by a double-acting cylinder 12, the shaft of which is connected to one of the brackets 9, which is attached to the upper jaws 10 and is located between the carriers 4. The cylinders 12 are operated hydraulically or pneumatically. You can work synchronously to the lower one movable jaw 13 to raise or lower, so that it remains parallel to the upper fixed jaw 10. Offset guide elements 15 are provided between the fixed profiles 8 and the vertically movable supports 4. These elements can have guides that are not shown in the drawing.

The upper flanges 14 of the profiles 3 form the clamping surfaces of the lower clamping jaw 13 and are almost at the same level as the surface of the rollers 7. As shown in FIG. 5, the flanges 14 are separated by a slot 16 through which a knife 17 slide can. The lower flanges 18 of the profiles 8 form the clamping surface of the upper jaw 10 and are also separated by a slot 19 which allows the knife 17 to pass through.

The opposite flanges 14 and 18 with the clamping surfaces formed thereon are shown flat on the drawing. However, they can have elevations or additional shapes in the form of claws, prisms etc. in order to be able to hold the band to be cut better, in particular if this band consists of a clearly elastic material and shows a recognizable wear pattern.

The two profiles 8, which form the upper fixed jaw 10, contain the cutting means consisting of a carriage with the knife 17 and a drive 21 by means of a chain which runs over two sprockets 22, 23 which are mounted on the ends of the profiles 8 . The sprocket 22 is driven by an electric gear motor 24. The other sprocket 23 is mounted on a chain tensioning device 25, in the vicinity of which each profile 8 has a lateral opening 26, which facilitates the assembly and disassembly of the knife 17 on the carriage 20. A removable housing 27, arranged above the lower jaw 13, protects the knife 17 in this zone. Another housing 28 protects the chain used to drive the carriage 20.

5 and 6, the carriage 20 is shown, which consists essentially of two side plates 30, between which the knife 17 is located. The ends of the chain are attached to the ends of the two plates 30.

The carriage is guided inside the profile 8 by means of ball bearings 33 serving as rollers. Here, the outer diameter of each ball bearing is smaller than the clear height inside the profile 8 in order to obtain a vertical play 34 of the carriage 20 and knife 17 and to allow the knife 17 to self-center on the band to be cut, as will be described later becomes. The plates 30 and the knife 17 are connected to one another by horizontal screws which pass through bores.

In Fig. 6 it is shown that each end of the knife 17 is provided with a cutting notch which is approximately V-shaped in the longitudinal profile and which has two parties 36 and 37 which are just opposite one another, one of which is symmetrical with respect to the horizontal Centerline is 38. Each V-shaped cutting edge ends in a central concave section 39. The knife 17 is preferably made of high-speed steel, which is cut out by means of a laser. The treatment of the cutting notch and the cutting angle depends on the product to be cut. In general, the sharpening is low so as not to make the cutting notch too sensitive. This construction makes it possible to produce a relatively thin knife 17 which can cut rubber or also metal reinforcements and other material which is embedded in the rubber. The symmetrical arrangement of the two cutting parts 36 and 37 of the knife creates a self-centering of the knife 17 with respect to the element to be cut, which is held between the two clamping jaws 10, 13. In the present case, it is the vertical play of the carriage 20 in the upper jaw 10 that allows self-centering.

The game can also be achieved by the knife 17 being movably mounted on the carriage 20. During the cut, the knife 17 is guided transversely to the band and through the slots 16 and 19, which are located between the two upper and lower jaws 10, 13.

The fact that the knife 17 has two pairs of cutting sections 36, 37 allows cuts to be made alternately in one direction and then in the other direction. But even in cases where an alternate cut is not intended, this type of knife can be of interest because it is after the If one cutting notch becomes dull, it is sufficient to reverse the working direction and to switch to the other cutting notch.

FIGS. 7 and 8 represent a variant of the knife guide in comparison to FIGS. 1 to 6 in order to cut particularly thick strips which are reinforced by very strong steel cables. The knife 50 is the essential element of a carriage 51, the upper jaw 10 containing an axis 52 with two ball-bearing plain bearings 53. In the lower jaw 13 there is an axle 54 with two ball-bearing slide bearings 55. The knife 50 has a straight-shaped cutting edge 50 'which runs obliquely in the cutting direction. It is preferably made of high-speed steel. The flanges 14 of the lower jaws 13 can be provided with fixed blades 56, which are also made of cutting steel. The blade 56 consists of two cutting edges 56 'on either side of the slot 16 of the lower jaw 13. As soon as the knife 50 encounters resistance during the cut, it is held in a position in which the slide bearings 53 of the carriage 51 against the upper flanges of the Press profiles 8, the sliding bearings 55 being pressed against the back of the flanges 14 of the profiles 3. In this position, the cutting notch 50 'exerts a force on the band to be cut, part of which is directed towards the lower jaw 13 and tries to clamp the inner ropes of the band to be cut between the cutting edge 50' of the knife 50 and the cutting edges 56 '. to squeeze the blades 56. In a variant, it is also possible that the knife 50 contains a notch such that a V-shaped cutting notch is formed in accordance with the embodiment described above.

The implementation of the method is extremely simple and can be automated without difficulty. The corresponding operating devices are installed in a control box 40 which, among other things. contains the electrical control unit and the power supply for the geared motor 24, as well as the electrohydraulic or electropneumatic units for actuating the cylinders 12.

3 shows the band 41 to be cut, which is, for example, a rubber conveyor belt reinforced by wires or metal cables 42, which has to be cut transversely according to a cutting line 43.

The band 41 placed on the rollers 7 can be manually pushed between the jaws 10 and 13 by an operator before the cutting process begins. In this way it is possible to quickly shred an old, worn conveyor belt into pieces that are easy to handle.

After the band 41 is in the correct position of the desired cutting line 43 between the jaws 10, 13, the jaws 10, 13 are first pressed against one another by actuating the cylinders 12. Then the movement of the knife 17, which is initially at one end of the clamping jaws 10, 13, which is generated by the drive, begins. Since the two cutting edges of the knife are arranged at an acute angle to one another, the band 41 is located between these two cutting edges during the cut, i.e. the knife 17 centers itself with respect to the band 41. The band material is gripped on both sides by the cutting edges of the knife 17, so that a symmetrical and particularly powerful cut takes place, which also easily cuts through metal reinforcements.

A further embodiment of the cutting device is shown in FIGS. 9 to 12. The jaws 10, 13 are connected at one end via a swivel 60. In order to be able to insert the band 41 from the other side between the jaw-like jaws 10, 13, the cutting device including the jaws 10, 13 can be opened completely at the end 61 facing away from the swivel joint 60. For this purpose, as can be seen in FIG. 10, the piston rod 62 of the cylinder 12 arranged there is separated from the lower clamping jaw 13 after loosening a securing bolt 63. The lower jaw 13 can then be lowered by pivoting about the joint 60 with respect to the upper jaw 10, and the band 41 can be inserted or removed laterally. This is of particular advantage for repair measures on endless conveyor belts that cannot be pushed into the cutting device at the end. At the same end of the clamping device, at which the swivel joint 60 is also located, a stop 64 which can be pivoted in between the two clamping jaws 10, 13 and with which the maximum opening angle of the clamping jaws 10, 13 can be limited is fastened.

Carrying eyelets 65 on the upper side of the cutting device allow it to be lifted to the desired place of use by means of a crane and, if necessary, to make cuts in a raised position. Instead of the lifting eyes 65 or in addition to this, guides for the tines of a forklift or another conveying device can also be provided.

In the embodiment of the clamping jaws 10, 13, the carriage 20 and the knife 17 shown in FIGS. 11 and 12, each of the two clamping jaws 10, 13 consists of two supports arranged in parallel in the form of a double T. The upper pair of supports forms the upper jaw 10, the lower pair of supports the lower jaw 13. By means of suitable spacing elements, the spacing of the supports is so small that the remaining longitudinal slots 16, 19 are just sufficient for the knife 17 to pass through. In this way, the knife 17 is guided predominantly by the edges of these longitudinal slots 16, 19. This guide is so scarce that the knife 17 behaves essentially rigidly in the longitudinal direction of the strip.

On the other hand, the knife 17 has a clear play 34 in the direction perpendicular to the flat sides 66 of the band 41. According to FIG. 12, this game 34 is composed of an upper game 34 'and a lower game 34' '. The upper game 34 'consists between support rollers 67 in the region of the upper longitudinal side of the carriage 20 and guide surfaces 68 of the clamping jaw 10 receiving the carriage. The lower game 34' 'exists between the underside 69 of the carriage 20 and the flange 18 of the clamping jaw there 10. The drive 21 in the form of the chain is fastened via a bolt 69 'near the underside 69 of the carriage 20 in order to achieve a force introduction near the knife 17.

As a result of the play of the carriage 20, the knife 17 rigidly connected to the carriage 20 automatically centers itself in the vertical direction with respect to the band 41 or the wires and metal cables 42 embedded therein. The wires therefore arrive precisely in that concavely ground section 39 when they are cut which the two symmetrically ground cutting edges 70, 71 of the knife converge. The distance between the cutting edges 70, 71 is here less than the diameter of the metal wires 42 to be cut. In the exemplary embodiment according to FIG. 12, they are V-shaped and thus in one acute angles to each other arranged cutting edges 70, 71 each formed straight. However, it is also possible to provide the cutting edges 70, 71 with a slightly convex contour in the direction of the band 41, for example with the contour of a parabola. Here, the cutting edges 70, 71 have an increasingly acute angle towards the end of the cutting notch at section 39. The average angle between the cutting edges 70, 71 should also be at least 10 ° and at most 45 ° in this case.

Instead of grinding the knife 17 itself, it is also possible to design the knife as a base body, in which suitable cutting inserts are then used, e.g. Cutting inserts made of Widia steel or ceramic. In this case, the knife or even the carriage does not have to be dismantled after the knife becomes dull. Rather, only the cutting inserts need to be replaced.

In order to achieve a uniform pressing pressure of the jaws 10, 13 over their entire length, a suitable bending line compensation can be provided, for. B. by a precisely determined, convex pre-bending of the two jaws 10, 13 to each other.

Reference list

1

Substructure

1'

frame

2nd

Trestle

3rd

U profile

4th

carrier

4 '

strut

5

traverse

6

Side member

7

role

8th

U profile

9

hanger

10th

upper jaw

12th

cylinder

13

lower jaw

14

flange

16

slot

17th

knife

18th

flange

19th

slot

20th

dare

21

drive

22

Sprocket

23

Sprocket

24th

Gear motor

25th

Chain tensioner

26

opening

27

casing

28

casing

30th

plate

33

Ball bearing, support roller

34

game

34 '

game

34 ''

game

36

first batch of knife

37

second batch of knife

38

Center line

39

concave section

40

Control box

41

tape

42

Wires, metal cables

43

Cutting line

50

knife

50 '

Cutting edge

51

dare

52

axis

53

bearings

54

axis

55

bearings

56

fixed blade

56 '

Cutting edge

60

Swivel

61

The End

62

Piston rod

63

Safety bolt

64

attack

65

Tragose

66

Flat side of the tape

67

Support roller

68

Leadership area

69

Underside of the car

69 '

bolt

70

first cutting edge

71

second cutting edge

Claims (13)

Process for cutting belts provided with reinforcing inserts, in particular for cutting conveyor belts from a reinforced elastomer, in which the belt is arranged between two clamping jaws, and for performing the cut, the clamping jaws with the belt arranged in between are pressed against one another, and at the same time using a knife a drive is guided through the band material along the clamping jaws and transversely to the longitudinal direction of the band,
characterized,
that the strip material is gripped on both sides by cutting edges of the knife, which form an acute angle between them and are each formed straight or convexly curved towards the strip. A method according to claim 1, characterized in that the knife is passed through the band material with a clear vertical play, the knife automatically centering with respect to the reinforcing insert enclosed in the band. Cutting device for belts provided with reinforcing inserts, in particular for conveyor belts made of a reinforced elastomer, with a clamping device consisting of two clamping jaws (10, 13) which are arranged transversely to the belt (41) and can be pressed against one another with the interposition of the belt (41), and with a Drive (21) knife (17) movable along the clamping device with at least one cutting edge (36, 70, 50 '),
characterized,
that the cutting edge (36, 70, 50 ') is straight or curved convexly towards the strip, that a further cutting edge (37, 71, 56') is arranged at an acute angle to the cutting edge (36, 70, 50 ') , and that the band (41) is between the two cutting edges (36, 70, 50 '; 37, 71, 56') during the cut. Cutting device according to claim 3, characterized in that both cutting edges (36, 70; 37, 71) are integrally formed on the knife (17). Cutting device according to claim 3 or 4, characterized in that both cutting edges (36, 70; 37, 71) are designed symmetrically to one another and together form an approximately V-shaped cutting notch. Cutting device according to one of claims 3 to 5, characterized in that the knife (17) has a clear play (34, 34 ', 34' ') in the direction perpendicular to the flat sides of the band (41), whereas the knife (17 ) behaves essentially rigid in the longitudinal direction of the strip. Cutting device according to one of claims 3 to 6, characterized in that the knife (17) is arranged on a carriage (20) which can be moved back and forth along the clamping device. Cutting device according to claim 7, characterized in that the knife (17) is rigidly attached to the carriage (20) and that the carriage (20) with clear vertical play (34, 34 ', 34' ') on one of the two clamping jaws ( 10, 13) of the clamping device is guided. Cutting device according to claim 8, characterized in that the carriage (20) is provided on its longitudinal side facing away from the knife (17) with support rollers (33, 67) which rest on guide surfaces (68) of the clamping jaw (10) receiving the carriage (20). can run, and that for moving the carriage (20) traction means (21) are provided which are attached to the carriage (20) at the level of the knife (17) facing half of the carriage (20). Cutting device according to one of claims 3 to 9, characterized in that the clamping jaw (10, 13) is provided with a longitudinal slot (16, 19) through which the knife (17) is guided. Cutting device according to claim 10, characterized in that the lateral guidance of the knife (17) takes place in whole or in part through the longitudinal slot (16, 19). Cutting device according to one of claims 3 to 11, characterized in that the clamping jaws (10, 13) can be pivoted relative to one another by means of a swivel joint (60), and in that the cutting device including the clamping jaws (10, 13) on its swivel joint (60) the opposite end (61) can be fully opened so that the band (41) can be inserted from the side between the open clamping jaws (10, 13). Cutting device according to claim 12, characterized by means (stop 64) for limiting the opening angle of the clamping jaws (10, 13).

Images