Cutting device for a heating wire cutting apparatus

Abstract

A cutting device (1) for a hot wire cutting device (2) for cutting plastic foam boards is proposed, comprising a strip element (3), a wire element (4) that can be heated to a cutting temperature, and a feed device (5) for feeding the wire element (4). To make changing the wire element (4) easier and significantly safer, the receiving device (6) is connected to the strip element (3) via a clamping mechanism (7) for clamping the wire element (4). The clamping mechanism (7) includes a clamping lever (8), and the clamping lever (8) is pivotally connected to the strip element (3) to move the wire element (4) from an unclamped position (a) to a clamped position (b) and vice versa by pivoting the clamping lever (8).

Description

[0001] The invention relates to a cutting device for a hot wire cutting device for cutting plastic, in particular plastic foam sheets according to the preamble of claim 1. State of the art

[0002] When insulating new buildings, plastic foam panels are often used, which are cut to size on-site using a hot wire cutter. Occasionally, the wire needs to be replaced due to defects or wear.

[0003] Previous hot wire cutting systems usually have an eyelet into which the wire must be pulled with the help of a spring bearing. However, this method is laborious and involves a significant risk of injury. US 2,987,598 discloses a cutting device for plastic tiles, comprising a strip element, a wire element which can be connected to a voltage in order to be heated to a cutting temperature when current flows through it, with a receiving device for receiving an end section of the wire element, wherein the receiving device is connected to the strip element via a tensioning mechanism for tensioning the wire element, wherein the tensioning mechanism has a tensioning lever which is articulatedly coupled to the strip element in order to transfer the wire element from an untensioned position to a tensioned position and vice versa by pivoting the tensioning lever. Object and advantages of the invention

[0004] The object of the invention is to propose a cutting device for a heating wire cutting device which not only simplifies the wire change but also makes it safer at the same time.

[0005] This object is achieved by the features of claim 1, based on a cutting device for a hot wire cutting device of the type mentioned in the introduction. Advantageous embodiments and further developments of the invention are possible by the measures mentioned in the subclaims.

[0006] The cutting device according to the invention is part of a cutting frame of a hot-wire cutting device for cutting plastic, in particular plastic foam panels, for example insulation or Styrofoam panels. The cutting device comprises at least one strip element that forms at least part of a cutting frame. The cutting device also comprises a wire element to which a voltage can be applied in order to heat it to a cutting temperature when current flows through it, and a feed device for feeding the wire element, wherein the wire element is connected to the feed device. Tensioning the wire element during insertion, but also re-tensioning the same wire element, is particularly important because the wire is always subject to expansion and contraction due to the strong heating compared to room temperature and the subsequent cooling to room temperature.

[0007] The feed device is designed to hold the wire element in place. This is achieved by a holding element that is part of the feed device. In one exemplary embodiment, the wire element is clamped by the holding element of the feed device; in another embodiment, the wire element is suspended from the holding element, for example, using a hook-and-eyelet system.

[0008] The cutting device also comprises a receiving device for receiving an end portion of the wire element, in particular the end portion of the wire element that is free or facing away from the feed device.

[0009] The wire element is mounted accordingly between the receiving device and the feed device along the strip element, whereby the strip element is provided for guiding the wire element.

[0010] In one embodiment, the wire element is partially stored in the feed device. In this case, the feed device also serves as a storage device for storing and maintaining wire or the wire element. For example, the feed device can comprise a spool element on which the wire element is stored wound and can be unwound when needed, for example, when the wire element needs to be replaced due to wear.

[0011] Accordingly, a cutting device according to the invention is characterized in that the receiving device is connected to the strip element via a tensioning mechanism for tensioning the wire element, wherein the tensioning mechanism has a tensioning lever and wherein the tensioning lever is articulatedly coupled to the strip element in order to transfer the wire element from an untensioned to a tensioned position and vice versa by pivoting the tensioning lever.

[0012] When replacing an old wire element with a new one, the new wire element is secured in the holding element of the feed device and picked up by the receiving device. The tensioning lever is initially in the untensioned position, so that the wire element is arranged untensioned between the holding element and the receiving device. By pivoting the tensioning lever into the tensioned position, the wire element is placed under tension and tensioned between the receiving device, which is arranged on the tensioning lever, and the holding element.

[0013] The person replacing the wire element does not have to manually tension the wire element in order to clamp it, but can simply insert the wire element into the holder and operate the clamping lever without much effort.

[0014] This makes changing the wire element easier and much safer.

[0015] In an exemplary embodiment, the wire element is fixed at a first end to the clamping lever and at a second end to a second leg of the cutting frame, such as the opposite leg, on the feed device, in particular to a holding element. Between these ends, the wire element is guided through the frame, in particular transversely through the frame, in particular perpendicular to at least one of the two legs or strip elements, so that the actual cutting area of ​​the cutting frame is formed by the wire element.

[0016] In one embodiment, the clamping lever has a first end and a second end, wherein the first end of the clamping lever is hingedly coupled to the strip element and the receiving device is fastened to the second end of the clamping lever.

[0017] The clamping lever is mounted for rotation about a rotation axis that runs transversely, in particular perpendicularly, to the direction of extension of the wire element. For example, pivoting the clamping lever increases the distance between the receiving device and the feed device, thereby tensioning the wire element.

[0018] In one embodiment, a fixing element is provided on the tensioning mechanism, wherein the fixing element can releasably fix the tensioning lever in one position, in particular in the tensioned position. This ensures that the wire element remains tensioned and cannot accidentally come loose.

[0019] In an exemplary embodiment, the tensioning mechanism is designed such that the tensioning lever is pivoted beyond a point at which the wire element has the highest tension. This point is often reached at the lever position where the wire element intersects the rotation axis. To release the wire element, the tensioning lever would have to be returned beyond this point. Since this requires a certain amount of force, the risk of accidentally releasing the lever is greatly reduced.

[0020] In one possible embodiment, the receiving device is hinged to the second end of the tensioning lever to transfer the wire element from an untensioned position to a tensioned position on the strip element during tensioning. When the tensioning lever is pivoted, the receiving device can always align itself so that the wire element is oriented in a single direction without it becoming kinked. This increases the service life of the wire, as kinks in the wire always create predetermined breaking points, precisely because the wire element expands and contracts due to the strong heating compared to room temperature, thus also being exposed to mechanical stress.

[0021] For example, the receiving device is coupled to the clamping lever at a first end and the wire element is received at the second end of the receiving device, so that the receiving device is aligned with the orientation of the wire element.

[0022] For example, the receiving device can always be aligned at the same angle to the wire element and / or to the strip element, in particular from the coupling point to the receiving point of the wire element, it can be aligned in alignment with the wire element.

[0023] Preferably, an engagement element is provided on the clamping lever, wherein the engagement element is designed for manually gripping and / or transferring the clamping lever from an unclamped position to a clamped position and vice versa. For example, the engagement element is designed as a gripping area for a hand or as a lever. The engagement element serves to simplify handling when pivoting the clamping lever.

[0024] Possible designs include, for example, a rope, a loop or a handle that can be grasped to swing the tensioning lever.

[0025] Advantageously, the feed device has at least one deflection device, wherein the wire element can be guided at least partially around the deflection device.

[0026] For example, the strip element forms one leg of a cutting frame on which the tensioning lever and the at least one deflection device of the feed device are arranged. Furthermore, the deflection device can be designed as a deflection pulley. In one possible embodiment, the wire element is fixed at a first end to the tensioning lever and at a second end to a second leg of the cutting frame, for example the opposite leg, on the holding element of the feed device, wherein the second leg of the cutting frame can be formed by a second strip element or by the same strip element. In between, the wire element is guided transversely through the frame. The deflection device is provided so that the wire element is guided to the tensioning mechanism essentially along the strip element without any strong local kinks.This has advantages during tensioning, as the force exerted on the wire element during tensioning creates a counterforce that is transferred to the bar element or balanced by the bar element without deforming or bending the cutting frame. At the same time, a deflection device allows the force acting on the wire during tensioning to be distributed across the entire wire element and not just on the part of the wire element that is guided along the bar element.

[0027] In a further design variant, a second deflection device is arranged on the second leg, so that the wire element is first guided along the second leg after the holding element before being guided transversely through the frame between the first and second deflection devices. The deflection devices allow for more flexible guidance and thus also the arrangement of the wire element within the cutting frame. This also allows for more flexible design of the section of the wire element used for cutting.

[0028] It is conceivable that the deflection device(s) is / are each arranged in the area of ​​a corner of the cutting frame. This is particularly interesting if one side of the cutting frame is open, i.e., if the cutting frame is constructed with only three strip elements or as a partial circle or similar structure.

[0029] Preferably, the receiving device is located at a distance from the feed device on the strip element. This allows the force exerted during tensioning of the wire element to be better balanced by the strip element.

[0030] In a preferred variant, the cutting device has a locking device, wherein the locking device is designed to releasably fix the clamping lever in the clamped position. By fixing the clamping lever in the clamped position, the clamping lever is secured against accidental opening despite the relatively high spring force, thus preventing injuries and generally making the cutting device safer to use. It is conceivable that the clamping lever can be releasably fixed to the strip element.

[0031] Advantageously, the securing device comprises a locking element and a receiving element, wherein the receiving element is arranged on the strip element and wherein the locking element is arranged on the clamping lever such that, when the clamping lever is in the tensioned position, the locking element can be releasably engaged with the receiving element. This enables particularly reliable securing. For example, the locking element is movably mounted relative to the clamping lever in order to be releasably fixable on or in the receiving element. It is also conceivable for the receiving element to be arranged on the clamping lever and the locking element on the strip element.

[0032] For example, the locking element is designed as a spring-loaded bolt that, when the clamping lever is in the clamped position, is pressed by a spring toward a receiving element formed as a recess in the strip element, thereby improving handling. The locking element can be at least partially received by the receiving element. Ideally, the direction of movement of the bolt is transverse to the pivoting direction of the clamping lever, thus realizing a holding effect of the clamping lever.

[0033] It is conceivable that the locking element can be released by moving the bolt out of the receiving element against the spring force. For this purpose, a release device can be provided on the strip element, which can be designed, for example, as a spring-loaded bolt. When the release device is actuated by the user, the bolt of the release device, for example, pushes the locking element out of the receiving element against the spring force of the spring arranged thereon, so that the holding effect of the clamping lever is canceled and the clamping lever can be pivoted from the clamped position to the relaxed position.

[0034] It is also conceivable that the locking element is designed as a sliding bolt, rotary lever or similar.

[0035] The cutting frame according to the invention for cutting plastic, in particular plastic foam boards, comprises a cutting device as described above. The wire element runs transversely through the frame and thus forms a cutting surface of the cutting frame. In one possible embodiment, the wire element runs perpendicular to at least one strip element.

[0036] A cutting device according to the invention for cutting plastic, in particular plastic foam sheets, with a base plate and a guide element for guiding plastic, in particular plastic foam sheets, is characterized in that the cutting device comprises a cutting device and / or a cutting frame as described above, wherein the cutting device or the cutting frame is mounted so that it can be displaced between two end positions relative to the base plate. In one possible embodiment, the cutting device or the cutting frame is designed to be tiltable, so that the cutting direction can be changed relative to the plastic workpiece, for example, tiltable about an axis perpendicular to the base plate and / or about an axis parallel to the base plate.

[0037] In one possible design variant, the cutting device comprises a base plate against which the plastic workpiece to be cut is placed, in particular a base plate with markings indicating dimensions and / or angles. The plastic workpiece is thus placed in a fixed position relative to the base plate. These markings can assist in cutting the plastic and / or adjusting the inclination of the cutting device or cutting frame.

[0038] The wire element or frame can also be moved relative to a plastic workpiece to be cut, which is in contact with the base plate, so that the wire element cuts through the plastic.

[0039] The workpiece can, for example, be insulation boards, in particular foam boards. Example

[0040] An embodiment of the invention is shown in the drawing and is explained in more detail below with reference to the figures.

[0041] In detail: Figure 1 shows a schematic structure of a cutting device as a section according to the invention, Figure 2 shows a schematic structure of another embodiment of a cutting device as a section according to the invention, Figure 3 shows a schematic representation of an embodiment of the cutting device according to the invention, Figure 4 shows a schematic structure of an embodiment of the cutting device according to Figure 2 with safety device and Figure 5 a schematic structure of a cutting device according to Figure 4 in a different perspective.

[0042] In Figure 1An embodiment of a cutting device 1 according to the invention is shown schematically. The figure shows a section of a strip element 3 of a cutting frame 11, on which a clamping mechanism 7 is arranged. The clamping mechanism 7 comprises a clamping lever 8, which is movably coupled to the strip element 3 at a first end. At a second end of the clamping lever 8, a receiving device 6 for receiving a wire element 4 is provided. The wire element 4 is releasably fixed to the receiving device 6.

[0043] The clamping lever is designed to pivot about a rotational axis d from an unclamped position a to a clamped position b and back. An engagement element 9 is attached to the clamping lever 8 and is designed to grip when the lever is pivoted.

[0044] The wire element 4 is mounted between the tensioning lever and a holding element 14 (not shown) of a feed device 5, wherein the wire element 4 is deflected here by means of a deflection device 10 and runs transversely through the frame via the strip element 3.

[0045] When the tensioning lever 8 is pivoted into the tensioned position b, the wire element 4 is tensioned beyond the deflection device 10 and can thus be used as a cutting edge of a heating wire cutting device 2 for cutting plastic.

[0046] Figure 2schematically shows an alternative embodiment of a cutting device 1 according to the invention, in which the receiving device 6 is articulatedly coupled to the clamping lever 8. In this embodiment, the receiving device 6 is designed such that, due to a clever choice of suspension on the clamping lever 8, it is always aligned in the extension of the wire element 4, in particular in the untensioned position a and the tensioned position b of the clamping lever 8.

[0047] In Figure 3 an embodiment of a heating wire cutting device 2 according to the invention is shown schematically.

[0048] The wire element 4 is stretched transversely through the cutting frame 11 between a receiving device 6 of a tensioning mechanism 7 and a holding element 14 of a feed device 5.

[0049] A plastic workpiece (not shown), such as an insulation board, is placed on a guide element 13 and leaned against the base plate 12. The cutting frame 11 with the cutting device 1 is movably mounted so that it can be moved between two end positions, wherein the end positions are selected such that a workpiece can be cut through by the wire element 4.

[0050] Figure 4 shows schematically a further embodiment of the cutting device according to Figure 2 , in which a safety device 15 is arranged on the tensioning lever 8. The safety device 15 is designed such that when the tensioning lever 8 is in the tensioned position b, a locking element 16 engages in a receiving element 17 and thus prevents unintentional release of the tensioning lever 8 and holds it in the tensioned position.

[0051] Figure 5A possible embodiment of a securing device 15 is shown as a sectional drawing from a further perspective. The securing device 15 comprises a locking element 16 and a receiving element 17. A bolt of the locking element, tensioned by a spring 20, is designed such that, when the tensioning lever 8 is in the tensioned position b, the bolt 20 is pressed by the spring 20 in the direction of the receiving device 17 and is partially received by the latter. The transverse forces thus acting prevent the tensioning lever from unintentionally pivoting from the tensioned position b into the untensioned position a.

[0052] In addition, the cutting device 1 has a release device 18 for releasing the locking of the securing device 15 and for releasing the clamping lever 8 so that it can be returned to the unclamped position a. For this purpose, the bolt 21 of the release device 18, tensioned by a spring 22, is pressed against the bolt 20 of the locking element 16 to release it from the receiving element 17. List of reference symbols

[0053] 1Cutting device 2Heating wire cutting device 3Ledge element 4Wire element 5Feed device 6Holder device 7Clamping mechanism 8Clamping lever 9Engaging element 10Deflection device 11Cutting frame 12Base plate 13Guide element 14Holding element 15Securing device 16Locking element 17Holder element 18Release device 19Bolt 20Spring 21Bolt 22Spring unclamped position bclamped position dRotation axis

Claims

1. Cutting device (1) for a heating wire cutting apparatus (2) for cutting plastic, in particular plastic foam boards, comprising a strip element (3), a wire element (4), which is connectable to a voltage in order during the flow of current to allow heating to a cutting temperature, and a supply device (5) for supplying the wire element (4), wherein the wire element (4) is connected to the supply device (5), and wherein the supply device (5) is designed to securely hold the wire element (4), with a receiving device (6) for receiving an end portion of the wire element (4), wherein the strip element (3) is provided for guiding the wire element (4), and the wire element (4) is mounted along the strip element (3), wherein the receiving device (6) is connected to the strip element (3) via a tensioning mechanism (7) for tensioning the wire element (4), the tensioning mechanism (7) having a tensioning lever (8) which is coupled in an articulated manner to the strip element (3) in order, by pivoting of the tensioning lever (8), to transfer the wire element (4) from an untensioned position (a) into a tensioned position (b), and vice versa.

2. Cutting device (1) according to Claim 1, characterized in that the tensioning lever (8) has a first end and a second end, wherein the first end of the tensioning lever (8) is coupled in an articulated manner to the strip element (3), and the receiving device (6) is fastened to the second end of the tensioning lever (8).

3. Cutting device (1) according to either of the preceding claims, characterized in that the receiving device (6) is coupled in an articulated manner to the second end of the tensioning lever (8) in order to transfer the wire element (4) into a position with respect to the strip element (3) during the tensioning from an untensioned position (a) into a tensioned position (b).

4. Cutting device (1) according to one of the preceding claims, characterized in that there is an engagement element (9) on the tensioning lever (8), the engagement element (9) being transferable for manually grasping and / or transferring the tensioning lever (8) from an untensioned position (a) into a tensioned position (b), and vice versa.

5. Cutting device (1) according to one of the preceding claims, characterized in that the supply device (5) has at least one deflecting device (10), wherein the wire element (4) is guided in part around the deflecting device (10).

6. Cutting device (1) according to one of the preceding claims, characterized in that the receiving device (6) is spaced apart from the supply device (5) on the strip element (3).

7. Cutting device (1) according to one of the preceding claims, characterized in that the cutting device (1) has a securing device (15), the securing device (15) being designed to releasably fix the tensioning lever (8) in a tensioned position (b).

8. Cutting device (1) according to one of the preceding claims, characterized in that the securing device (15) has a locking element (16) and a receiving element (17), the receiving element being arranged on the strip element and the locking element being arranged on the tensioning lever (8) in such a way that, in a tensioned position (b) of the tensioning lever (8), the locking element (16) is releasably engageable in the receiving element (17).

9. Cutting frame (11) for cutting plastic, in particular plastic foam boards, characterized in that the cutting frame (11) comprises a cutting device (1) according to one of the preceding claims.

10. Cutting apparatus (2), for cutting insulating boards, in particular foam boards, with a baseplate (12) and a guiding element (13) for guiding plastic, in particular plastic foam boards, characterized in that the cutting apparatus (2) comprises a cutting device (1) and / or a cutting frame (11) according to one of the preceding claims, the cutting device (1) or the cutting frame (11) being mounted displaceably between two end positions relative to the baseplate (12).

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