CUTTING DEVICE

Abstract

A cutting device for cutting off pieces from a strip of material, and a device for producing plastic pieces, and which includes at least one cutting device.

Claims

1. A cutting device, comprising: a cutter unit having a rotatably mounted disc blade configured to rotate for the purpose of cutting an extruded strip of material; a conveyor unit to convey, in a longitudinal direction, the extruded strip of material to the cutter unit; and a guide unit having an actuator to guide the cutter unit relative to the conveyor in the longitudinal direction, and a transverse direction that is perpendicular to the longitudinal direction.

2. The cutting device of claim 1, wherein the cutter unit comprises a blade carriage to receive the disc blade, the blade carriage being movable in the transverse direction along a guide profile of the guide unit.

3. The cutting device of claim 2, wherein the guide unit comprises a chain carriage and a base plate that is not movable with the chain carriage, the chain carriage having a chain between sprocket wheels, the chain being fixed to the base plate, at a first position.

4. The cutting device of claim 3, wherein the blade carriage is fixed to the chain, at a second position, the second position being disposed on a strand of the chain that is opposite the first position.

5. The cutting device of claim 3, wherein the chain carriage is movable in the transverse direction by the actuator on the guide unit.

6. The cutting device of claim 3, wherein guide profile is fixed to the chain carriage.

7. The cutting device of claim 3, wherein guide profile is fixed to the base plate.

8. The cutting device of claim 1, wherein the guide unit is mounted for suspension so as to be rotatable about an axis that is perpendicular to the conveyor unit.

9. The cutting device of claim 1, further comprising a controller to control the cutter unit and the conveyor unit such that a velocity of the conveyor unit and/or the velocity of the cutter unit in the longitudinal direction and/or in the transverse direction, and/or a rotation of the guide unit about a vertical axis that is perpendicular to the extruded strip of material, is predefined by the controller.

10. The cutting device of claim 1, wherein the drive of the disc blade is constituted by a rack and a pinion that meshes in the rack and that is rotationally solid with the disc blade.

11. The cutting device of claim 1, wherein the drive of the disc blade is constituted by a motor that directly drives the disc blade.

12. The cutting device of claim 1, wherein the cutter unit has a shoe having a cutting edge opposite the disc blade.

13. The cutting device of claim 12, wherein the shoe comprises at least one air nozzle to detach the extruded strip of material from the conveyor unit after cutting by the cutter unit.

14. The cutting device of claim 12, further comprising a contact pressure spring to bias the disc blade in a direction towards the cutting edge of the shoe.

15. The cutting device of claim 1, wherein the cutter unit comprises at least one air nozzle to detach the extruded strip of material from the conveyor unit after cutting by the cutter unit.

16. The cutting device of claim 1, wherein the disc blade is configured to be alignable in the transverse direction with respect to the conveyor unit.

17. The cutting device of claim 1, wherein a vertical pitch angle of the disc blade is configured to be set with respect to the conveyor unit.

18. A cutting device, comprising: a cutter unit having a rotatably mounted disc blade configured to rotate for the purpose of cutting an extruded strip of material, and a shoe having a cutting edge opposite the disc blade; a conveyor unit to convey, in a longitudinal direction, the extruded strip of material to the cutter unit; and a guide unit having an actuator to guide the cutter unit relative to the conveyor in the longitudinal direction, and a transverse direction that is perpendicular to the longitudinal direction, wherein the shoe has at least one air nozzle to detach the extruded strip of material from the conveyor unit after cutting by the cutter unit.

19. A device for producing plastic pieces, comprising: at least one extruder for extruding a strip of material, the extruder having a die through which the strip of material is extruded; and at least one cutting device having: a cutter unit having a rotatably mounted disc blade configured to rotate for the purpose of cutting the extruded strip of material; a conveyor unit to convey, in a longitudinal direction, the extruded strip of material to the cutter unit; and a guide unit having an actuator to guide the cutter unit relative to the conveyor in the longitudinal direction, and a transverse direction that is perpendicular to the longitudinal direction.

Description

DRAWINGS

[0024] Embodiments will be illustrated by way of example in the drawings and explained in the description below.

[0025] FIG. 1 illustrates a side view of a cutting device, in accordance with embodiments.

[0026] FIG. 2 illustrates a top view of the cutting device of FIG. 1.

[0027] FIG. 3 illustrates a chain carriage and a blade carriage of a cutting device, in accordance with embodiments.

[0028] FIG. 4 illustrates a perspective view of a part of a cutting device, in accordance with embodiments.

[0029] FIG. 5 illustrates a perspective view of a part of a cutting device, in accordance with embodiments.

[0030] FIG. 6 illustrates a perspective view of a part of a cutting device, in accordance with embodiments.

[0031] FIG. 7 illustrates a perspective view of a part of a cutting device, in accordance with embodiments, the cutter unit 2 being represented in section.

[0032] FIG. 8 illustrates possible disc blades for a cutting device, in accordance with embodiments.

DESCRIPTION

[0033] FIGS. 1 and 2 illustrate a schematic arrangement of a cutting device during a cutting process, in accordance with embodiments.

[0034] The cutting device may be used to cut off or otherwise remove pieces from a strip 1 of material/workpiece, and comprises a cutter unit 2, a conveyor unit 3 for conveying the strip 1 in a longitudinal direction, and a guide unit 4. The cutter unit 2 may be guidable in the longitudinal direction (along v4) via the guide unit 4, and in a transverse direction (along v6) that is perpendicular to the longitudinal direction on the guide unit 4.

[0035] The strip velocity v1 of the strip 1 and the guide unit velocity v4 of the guide unit 4 may be operatively linked to each other, for example, via a control unit. In accordance with embodiments, in the simplest form, the strip velocity v1 and the guide unit velocity v4 are equal, i.e., synchronized.

[0036] FIG. 2 illustrates a top view of the arrangement of FIG. 1. The cutter unit 2 of the cutting device is suspended so as to be rotatable under control about a vertical axis 13. The strip 1 can be guided along the entire device via the conveyor unit 3. The disc blade 6 of the cutter unit 2 is movable along the cutting device, likewise controlled by a control unit. If the three motions of the device, namely, v4 (velocity of the guide unit 4 in the longitudinal direction), v6 (velocity of the disc blade 6 in the transverse direction), and v13 (angular velocity of the guide unit 4 about the normal axis 13) are coordinated with the velocity of the strip v1, a desired curved cutting line can be obtained.

[0037] If the velocity of the device just corresponds to the velocity of the guide unit 4, i.e., v13=0 and v4=v1, then a straight cut in the transverse direction is obtained. The velocities for other curves can be calculated, and can be implemented by a control unit.

[0038] It would be possible to represent v4 and v13 each with their own drive, but preferably these two motions are generated via a common drive.

[0039] FIG. 3 illustrates the basic structure of the cutting device, in particular the guidance of the chain carriage 9 and of the blade carriage 7. The sprocket wheels 11, with the chain 12, are mounted on the chain carriage 9. The latter is moved by an actuator 5. The chain 12 at the top is fixed to the base plate 10. The blade carriage 7, with the disc blade 6, is connected to the chain 12 at the bottom, and moves along a guide profile 8 that is attached to the chain carriage 9 (the guide profile 8 could also be attached to the base plate 10). When the actuator 5 is actuated, the disc blade 6 runs at double velocity, and therefore also travels double the distance. It is thereby possible to use an actuator 5 having a stroke half as long as without a structure having a chain carriage 9.

[0040] In accordance with embodiments, although the carriages 7, 9 are illustrated as driven by a single actuator, embodiments are not limited thereto. For example, the carriages 7, 9 could be driven via separate actuators (the chain 12 then need not be attached to the base plate 10).

[0041] FIG. 4 illustrates the design of the blade carriage 7. The blade carriage 7 uses a rotatable disc blade 6, which can be made to rotate by a drive, for the purpose of cutting. The outer circumference of the disc blade 6 is realized as a cutting edge. This type of rotating blade is known, for example, from the foodstuffs industry (pizza cutting) and the textile industry. The rotating disc blade allows optimal initial cutting into the strip material 1. Since, for example, the surface of an extruded strip forms a semi-solid skin with the ambient air as a result of cooling, the rotating disc blade 6 is advantageous in effecting an initial cut.

[0042] The rotating disc blade 6 may be driven directly by a motor, but preferably it is driven, as represented in FIGS. 3 to 7, via a pinion 15, which rolls on a rack 14 that is fixed to the frame, or to the base plate 10. If the disc blade 6 is directly driven, the pinion 15 and rack 14 are omitted; however, this requires the mounting of a drive motor. The latter runs in synchronism with the guide unit 4; the electric or pneumatic energy supply must likewise be in synchronism. For this reason, the solution comprising the pinion 15 and rack 14 is preferred. The size of the pinion 15 determines the rotational speed of the disc blade 6. The size of the pinion 15 is limited by the space available above the strip 1 and the diameter of the shaft used.

[0043] As illustrated in FIGS. 5 and 6, the shoe 16 may be disposed beneath the rotating disc blade 6, in order to prevent the strip 1 from moving out of place.

[0044] FIG. 6 illustrates a 3D representation of the cutter unit 2. The blade 6 may be pressed against the wall of a recess in the shoe 16 by a contact pressure spring 18. The recess has a sharp edge that functions as a second cutting edge 17. As a result, the material of the strip is parted, not only via pressure, but by the principle of a pair of shears. For this reason, also, an arrangement comprising a shoe 16 is preferred. Clearly, all of these elements, in particular the two cutting edges, are hardened. The parts that come into contact with the strip material 1 may be provided with an anti-stick coating to prevent sticking to the conveyor unit 3.

[0045] FIG. 7 illustrates a section through the cutter unit 2.

[0046] FIG. 8 illustrates a selection of various possible shapes of the disc blade 6, namely, circular, polygonal, in this case octagonal, fluted and toothed, or star-shaped, each being of a symmetrical design. Not illustrated here, but likewise possible, would be fluted or toothed profiles of an asymmetrical design, for example asymmetrical saw teeth. Only the use of a disc blade 6 of symmetrical design is appropriate for cutting in a forward and return direction.

[0047] A fluted or toothed design of the disc blade 6 is advantageous in effecting the initial cut into a strip 1. The teeth draw the material to the cutting edges, and consequently in this case the strip 1 is less likely to buckle. Circular and polygonal disc blades 6 allow easier resharpening of the respective cutting edge.

[0048] The term coupled or connected may be used herein to refer to any type of relationship, direct or indirect, between the components in question, and may apply to electrical, mechanical, fluid, optical, electromagnetic, electromechanical or other connections. In addition, the terms first, second, etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

[0049] This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of embodiments is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspects, may be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.

LIST OF REFERENCE SIGNS

[0050] 1 strip

[0051] 2 cutter unit

[0052] 3 conveyor unit

[0053] 4 guide unit

[0054] 5 actuator

[0055] 6 disc blade

[0056] 7 blade carriage

[0057] 8 guide profile

[0058] 9 chain carriage

[0059] 10 base plate

[0060] 11 sprocket wheel

[0061] 12 chain

[0062] 13 axis perpendicular to the conveyor unit

[0063] 14 rack

[0064] 15 pinion rotationally solid with the disc blade

[0065] 16 shoe

[0066] 17 cutting edge

[0067] 18 contact pressure spring

[0068] v1 velocity of the strip (longitudinal direction)

[0069] v4 velocity of the guide unit (longitudinal direction)

[0070] v6 velocity of the disc blade (transverse direction)

[0071] v13 angular velocity of the guide unit about the axis