US20200277152A1

US20200277152A1 - Edge tape cassette for edge tapes

Info

Publication number: US20200277152A1
Application number: US16/753,099
Authority: US
Inventors: Thomas Hampel; Stefan Hüsener; Tim Kottkamp; Uwe Seifert
Original assignee: IMA Schelling Deutschland GmbH
Current assignee: IMA Schelling Deutschland GmbH
Priority date: 2017-10-26
Filing date: 2018-10-18
Publication date: 2020-09-03
Also published as: EP3700726A1; DE102017125039B3; PL3700726T3; EP3700726B1; BR112020003527B1; BR112020003527A2; CN111246983B; WO2019081335A1; CN111246983A; CA3074171A1

Abstract

An edge tape cassette for receiving edge tapes comprising a cassette housing, in which a winding core is arranged, which fixedly holds an edge tape that is existent as a container in the form of a wound-up roll. Furthermore, the edge tape cassette additionally has a receiving element, which is rotatable mounted in the edge tape cassette, and to which the winding core is attached, in particular in a detachable manner.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is the US National Phase of and claims priority on and the benefit of International Application No. PCT/EP2018/078541 having an international filing date of 18 Oct. 2018, which claims priority on and the benefit of German Patent Application No. 102017125039.5 having a filing date of 26 Oct. 2017.

BACKGROUND OF THE INVENTION

Technical Field

The invention relates to an edge tape cassette for edge tapes.

Prior Art

When manufacturing plate-shaped workpieces, in particular from wood or wood substitute materials, such as fiber boards, chipboard, HDF boards, MDF boards, laminates or the like, it is usually the case that the narrow sides thereof are provided with strip-shaped lamination materials, so-called edge tapes, when processing the plate-shaped workpieces. Since such plate-shaped workpieces are used in particular in regions in which the visual appearance plays a major role, such as especially in the construction of furniture, but also in doors, interior cladding of buildings and the like, there are a large number of different edge tapes, in order to allow different decorative and/or functional configurations of the resulting plate-shaped workpieces and of the products that may be manufactured therefrom.
The edge tapes must be made available at the respective production facilities, whereby a large number of different edge tapes must be kept available, depending on the planned production. Due to the fact that the narrow sides to be laminated span the entire workpiece, a relatively large length portion is required per workpiece, i.e. large quantities of the edge tapes are processed in the context of modern and efficient production.
The edge tape manufacturers provide the edge tapes for containers that are usually wound-up as spirals. The edge tapes are then regularly secured with aids such as tapes that hold the windings of the spiral-shaped containers together and are delivered in standard packaging such as boxes or crates, or on pallets. It is also possible for the edge tapes to be wound-up onto—usually ring-shaped—winding cores. These give the container additional stability, which is particularly advantageous in the case of thin edge tapes and/or edge tapes made of paper.
In practice, it is now necessary to permanently equip the production facilities with new edge tapes during operation. In practice, the spiral windings represent a not inconsiderable problem with regard to their handling. If these are unpacked from the boxes or the fixing tapes, which may hold the winding together, are loosened, it regularly happens that the edge tapes unwind. These then have to be rewound manually and regularly under time pressure and fed to the production facility. In practice, this results in a not inconsiderable amount of personnel, in the worst case there is even an interruption in operation if an accidentally unwound edge tape cannot be replaced or rewound quickly enough with one that is still unwound.
For this reason, considerations have already been made in the past to simplify or automate the handling of the edge tapes. For example, fully automated and/or cassette-based systems have been developed. Such systems are disclosed, for example, in EP 1 860 593 B1 or EP 1 860 596 B1.
A disadvantage of the previously known systems is that, on the one hand, they are comparatively complex and therefore expensive. On the other hand, the problem of loading is only shifted, i.e. the handling problems no longer occur directly at the loading apparatus, but for example when filling the corresponding cassettes.

BRIEF SUMMARY OF THE INVENTION

The invention is therefore based on the object of providing an edge tape cassette which allows for a solution to the handling problem described above for processing the edge tapes.
The object is achieved by an edge tape cassette for receiving edge tapes comprising a cassette housing, in which a winding core is arranged, which fixedly holds an edge tape, that is existent as a container in the form of a wound-up roll, characterized in that the edge tape cassette additionally has a receiving element which is rotatably mounted in the edge tape cassette and on which the winding core is attached, in particular in a detachable manner. The features of the dependent claims relate to advantageous embodiments.
The edge tape cassette according to the invention for receiving edge tapes has a cassette housing in which a winding core is arranged, which fixedly holds an edge tape. The edge tape itself is existent as a container or wrap in the form of a wound-up roll. According to the invention, in addition to the winding core, the edge tape cassette has a receiving element which is rotatably mounted in the edge tape cassette and to which the winding core is attached, in particular in a detachable manner.
By attaching the winding core to the receiving element, it is very easy to equip the receiving element with the edge tape. Optionally, the edge tapes that are already wound-up on the winding core can then be attached to the receiving element on one side by a simple measure. In addition, the receiving element can serve as an additional swing body which is set in rotation during rotation (i.e. when winding or unwinding the edge tape).
It is preferably provided for this purpose that the winding core is attached only to one side of the receiving element. In this way, a simple assembly of the receiving element or the edge tape cassette is possible. In addition, the receiving element only needs to be supported on one side on the housing of the edge tape cassette.
It is particularly preferably provided that the receiving element has a base body, which is preferably at least essentially rotationally symmetrical and at least essentially disk-shaped. This base body is rotatably mounted in the cassette housing and can then serve as a flywheel when rotating. In addition, the disk-shaped configuration has the advantage that it can also be rotated by additional drive means, for example drive wheels or drive disks. These drive means then do not have to act on the axis of rotation, but can, for example, be arranged so as to act tangentially in relation to the receiving element.
In a preferred variant it is provided that the winding core is connected to the receiving element in a rotationally fixed manner. At least a part of the receiving element can extend radially beyond the radial extent of the winding core from its axis of rotation. This extending part can preferably be used for the container to at least partially rest on the receiving element. In this way, for example, when rewinding the edge tape, a system can be created which helps to ensure that the tape cannot slip sideways during the winding.
According to a further embodiment of the present invention, the winding core can be designed as an internal clamping device for fixing the wound-up edge tape. The inner clamping device is designed to exert outward forces on an inward-facing surface of the container. This inward-facing surface of the container can be formed by the innermost winding of the edge tape, but it can also be an inward-facing surface of a winding core on which the edge tape is wound.
It has been shown that it is possible to securely fix a wound-up edge tape to the receiving element with such an internal clamping device. The inner clamping device is particularly characterized in that it can exert outward forces on an inward surface of the container.
Furthermore, such an internal clamping device can be implemented as a preferably purely mechanical device in a simple and inexpensive manner. This makes it possible to provide a large number of receiving elements. The edge tapes, which are delivered in a wound-up form, can then be fixed to the receiving elements by means of the internal clamping devices upon a certain lead time before they are used. It is then possible to provide the fixed edge tapes with the receiving elements together at the production facilities at the moment when they are actually needed. By securely fixing the edge tape to the receiving element, this critical step in the handling of the edge tape is simplified on the one hand and, on the other hand, it is designed securely with regard to unwanted unwinding of the edge tape.
It is also advantageous here if the receiving element has an at least substantially disk-shaped base body. The disk-shaped base body makes it easier to equip the receiving element with the edge tape. The receiving element can then be placed at a suitable workstation, preferably with the base body pointing downward and the inner clamping device pointing upward. The edge tape delivered in wound-up form can be placed on the base body around the inner clamping device. Any packaging materials and fixing tapes can then be removed without the risk of unwanted unwinding of the edge tape resting on the base body. The edge tape resting on the base body is then fixed by means of the inner clamping device. The composite formed in this way from the edge tape and the receiving element can then be safely handled and can be fed directly to a production facility or temporarily stored until it is used.
The base body is preferably at least essentially rotationally symmetrical. The rotationally symmetrical design of the base body—and in particular of the receiving element—makes it easier to accommodate the receiving element rotatably in the edge tape cassette. The rotatable reception is advantageous because the unhindered rotation of the receiving element facilitates the unwinding of the edge tape during production.
The receiving element advantageously has a corresponding bearing element for its rotatable mounting on the housing of the edge tape cassette. This can be, for example, an axis, which is preferably arranged centrally on the receiving element. For safe, rotatable mounting of the receiving element, it is particularly advantageous if it has two bearing elements on sides of the receiving element facing away from one another.
The inner clamping device of the receiving element preferably has a plurality of clamping elements. These can be clamped to fix the wound-up edge tape against the inward-facing surface of the container of the edge tape. It can be advantageous to design the clamping elements to be interchangeable. In this way, different inner diameters of the container of the wound-up edge tape can be taken into account by selecting appropriate clamping elements. It is also possible to use suitable clamping elements for different widths of the edge tape. The clamping elements preferably act in the manner of clamping jaws on the container of the wound-up edge tape.
The clamping elements are preferably guided displaceably on the base body along a clamping direction in order to fix the edge tape. The clamping direction has at least one radial component in relation to the disk-shaped extension of the base body. This makes it possible to move the clamping elements towards the inwardly facing surface of the edge tape container in order to fix said edge tape. The clamping direction is preferably oriented at least in the radial direction in relation to the disk-shaped extension of the base body. Such an at least essentially radial orientation moves the clamping elements in the direct direction towards the inwardly facing surface when the container of the edge tape is fixed with the inner clamping device.
The inner clamping device particularly preferably has a rotatable rotary element for fixing the container of the edge tape. In this context, the inner clamping device is designed in such a way that rotation of the rotary element relative to the base body causes the edge tape to be fixed. The rotary element is preferably arranged centrally on the disk-shaped base body. Through this central arrangement, the rotary element can develop its outward clamping effect evenly distributed over its circumference. According to a preferred embodiment, the clamping elements are displaced along their respective clamping direction by the rotation of the rotary element. This can be accomplished, for example, by the fact that the rotary element slides on sliding surfaces on the clamping elements that are preferably designed as spirals, when said rotary element rotates, wherein said clamping elements are displaced outwards, and thus against the inwardly facing surface of the container, due to the, in particular spiral, design of the sliding surfaces.
The disk-shaped base body preferably has a first connecting element. The rotary element also preferably has a second connecting element. The first and the second connecting element are used to connect a tool for fixing the edge tape to the receiving element. As a result, no control elements, which may interfere with the handling of the edge tape, have to be provided on the receiving element. To actuate the inner clamping device, it is sufficient to temporarily connect a tool to the receiving element, in particular to bring about the rotation of the rotary element. As a result, the tool can have appropriate dimensions, such as, for example, a corresponding lever length, in order to ensure secure clamping using sufficient clamping forces. The lever lengths which are advantageously used for this purpose in order to generate sufficient forces may require a size of the tool, which would be a hindrance if the edge tape were firmly connected to the receiving element when the edge tape was applied to the inner clamping device. Connecting elements for temporary attachment of the tool thus make handling much easier.
The receiving element preferably has a fixing element for fixing the rotary element relative to the base body. Such a fixing element makes it possible to effectively secure the container of the edge tape against inadvertent loosening by means of the inner clamping device. The fixing element can advantageously be designed in such a way that it brings about a non-positive prevention of rotation of the rotary element relative to the base body. This can be done, for example, with a screw that creates a frictional connection between the rotary element and the base body for fixing the rotary element.
According to a preferred embodiment it is provided that the edge tape cassette has a braking device for braking a rotation of the receiving element and/or a locking device for blocking the rotation of the receiving element and/or an acceleration device for accelerating a rotation of the receiving element, which engages preferably in the region of the outer edge of the base body on the base body.
A braking device has the advantage that it can be used to tighten the edge tape. On the one hand, this stabilizes the fixation of the edge tape on the winding core, and on the other hand, the tightening of the edge tape has an advantageous effect on the further manufacturing or processing of the edge tape. The particular advantage of such a braking device in connection with the receiving elements according to the invention is that the braking device can act directly on the receiving element. Due to the differences in the mechanical properties of the edge tape, braking devices that act directly on an edge tape are comparatively problematic. In contrast, in an edge tape cassette according to the invention, the braking device can advantageously act on the receiving element and thus indirectly on the edge tape. For example, the braking device can be designed in the manner of a disc brake and can engage the base body. This makes it possible to implement a reliable and at the same time simple braking device.
Likewise, the same device or an additional device can also be provided for fastening or fixing the receiving element in the edge tape cassette. This is particularly suitable when the edge tape cassette is to be transported such that the edge tape cannot unintentionally unwind.
It is also advantageous if the edge tape cassette has an acceleration device for accelerating a rotation of the receiving element. Such an acceleration device can be implemented, for example, by a friction roller acting on the outer edge of the receiving element or its base body. In this way, the forces required for acceleration can be transmitted as frictional forces. Alternatively, however, it is also possible to provide a toothing between the receiving element or the base body and the acceleration device.
In order to ensure an unintentional detachment of the edge tape from the winding core when the roll has already been largely unwound, it is provided according to an advantageous embodiment of the present invention that the end of the edge tape lying on the winding core is connected to the winding core, in particular is clamped or glued.
According to a further preferred embodiment of the present invention, the edge tape cassette according to the invention has an exit point at which the free end of the edge tape can be withdrawn from the cassette. Further devices can be provided around this exit point. For example, there may be a lateral guide such that the edge tape is guided laterally in the region of its narrow sides at the exit point. In this way, it is ensured that slipping sideways when pulling the edge tape out of the edge tape cassette is avoided.
Furthermore, the edge tape cassette according to the invention can have a clamping apparatus for clamping the free end of the edge tape. This prevents the edge tape from accidentally sliding back into the cassette before it can be processed. It can preferably be provided here that the clamping action with respect to the edge tape can be canceled again, such that the further operation or the retraction of the edge tape into an edge processing apparatus is not impaired.
In particular, it can be provided that the clamping device, preferably on the inside of the cassette housing, is arranged in the region of the exit of the edge tape from the cassette housing, in particular adjacent to the abovementioned exit point.
An information device can also be provided on the edge tape cassette according to the invention, which contains, for example, information about which type of edge tape is contained inside the cassette; such information can include, for example, the edge height, edge width, edge color, existing linear meters of the edge, or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in more detail below with reference to FIGS. 1 to 6.

FIG. 1 shows a side view of an edge tape cassette according to the invention.

FIG. 2 shows a sectional view along the line A-A through the edge tape cassette according to the invention, according to FIG. 1.

FIG. 3 shows a perspective view of an exemplary receiving element according to the invention having an edge tape received thereon.

FIG. 4 shows a schematic illustration of the inner clamping device of the receiving element from FIG. 1 from the side normally facing the base body in the released state.

FIG. 5 shows a schematic illustration of the internal clamping device shown in FIG. 2 in the clamped state.

FIG. 6 shows a schematic perspective illustration of the inner region of the base body of the receiving element shown in FIG. 1 by way of example.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The edge tape cassette shown in FIGS. 1 and 2 has a cassette housing 18 in which the receiving element 1 according to the invention is accommodated. A winding core 3, which rotates with the receiving element 1, is preferably detachably attached to the receiving element. An edge tape 2 is wound-up on the winding core 3. The free end 2 a of the edge tape 2 can be removed from the cassette housing 18 at an exit point. The winding core 3 is in particular connected to the receiving element 1 in a rotationally fixed manner. The rotation of the receiving element 1 thus causes a rotation of the winding core 3 and thus, depending on the direction of rotation, a winding or unwinding of the edge tape 2. In the edge tape cassette according to the invention, there are several options for how the edge tape can be wound or unwound. For this purpose, optional drives 19, 20, 22 can be provided at various points. The edge tape cassette is usually inserted into a slot in a cassette supply. A first option for the drive would then be, for example, the drive wheel 19, which can be driven, for example, via a switchable drive belt in the cassette shaft (not shown). A further possibility would be, for example, a drive roller 20 on an external tool (for example, a robot), said drive roller being delivered to the receiving element 1 at a specific position 21 on the upper side (or another narrow side) of the cassette. The frictional connection between the drive roller 20 and the receiving element 1 can cause the receiving element 1 to rotate and thus the edge tape roller 2 to rotate. A further option consists, for example, of detecting and conveying the edge tape end 2 a directly at the outlet opening of the edge tape cassette by means of a pulley 22. All of these drives can be provided optionally, but can also be present in any combination.
Furthermore, a device 24 can be provided which is capable of either braking the edge tape roll 2 or the receiving element 1 or even fixing it completely, so that rotation is no longer possible. The latter can be used for transport purposes, for example.
Finally, the edge tape cassette can have a clamping device 23 in the region of the outlet opening, which is designed to clamp the pulled-out edge tape end 2 a in the region of the outlet opening such that it does not accidentally slip into the edge housing 18. It can also be provided that the clamping effect of the clamping device 23 can be canceled such that the edge tape can be guided out of the cassette housing 18 without any problems and without hindrance. At the same time, this clamping device can also be designed as an edge guide, and in particular toward the narrow sides, guide elements can be present which prevent the edge tape 2 a from slipping sideways.
The receiving element 1 according to the invention, which is now to be explained on the basis of a preferred embodiment with reference to FIGS. 3 to 6, has a winding core for fixing the wound-up edge tape 2. This winding core can preferably have an internal clamping device 3, as will be described below. However, the invention works with any type of winding core, an inner clamping device 3 described below is therefore only to be understood as an option.
The inner clamping device 3 is designed to exert outward forces on the inward surface 17 of the container of the wound-up edge tape 2.
The exemplary receiving element 1 advantageously has a disk-shaped base body 4. The base body 4 is advantageously at least essentially rotationally symmetrical.
The inner clamping device 3 advantageously has a plurality—in the example shown, three—clamping elements 5. These can be clamped to fix the wound-up edge tape 2 against the inwardly directed surface 17 of the container of the wound-up edge tape 2. The clamping elements 5 thus advantageously act in the manner of clamping jaws.
The clamping elements 5 are each slidably guided along the clamping direction X on the base body 4 for fixing the edge tape 2. In the example shown, the clamping direction X advantageously points in the radial direction in relation to the disk-shaped extension of the base body 4. The base body 4 has guiding elements 6 in order to allow the guiding of the clamping elements 5 along their respective clamping direction X. The guide elements 6 can be seen in FIG. 4. They engage in complementary grooves 7 into the clamping elements 5, which can be seen in FIGS. 2 and 3, and thus guide the movement of the tensioning elements 5.
Furthermore, the receiving element 1 according to the invention advantageously has a rotary element 8. The rotary element 8 is advantageously arranged centrally on the base body 4. The rotary element 8 is rotatable for fixing the edge tape 2. In the example shown, the rotatability is advantageously brought about by a rotatable mounting of the rotary element 8 on the base body 4. For this purpose, the rotary element has a central circular recess 9, into which a guide element 10 engages, which is received on the base body 4 and advantageously also has a circular design.
When the rotary element 8 rotates, contact surfaces 11 of the rotary element 8 slide, preferably in a spiral shape, on corresponding contact surfaces 12 of the clamping elements 5. The clamping elements 5 are thereby pressed outwards and against the inward surface 17 of the container of the edge tape 2. The mode of operation is evident from the comparison of FIGS. 2 and 3. Starting from FIG. 2, rotation of the rotary element 8 causes the contact surfaces 11 and 12 to slide against one another, such that the clamping jaws 5 are pressed outward in the radial direction until they reach a position shown in FIG. 3 by way of example, in which the edge tape 2 is fixed.
In order to ensure a better connection of the inner clamping device 3, the rotary element 8 and the clamping elements 5 have interlocking grooves 13 in the region of their contact surfaces 11 and 12. The interlocking grooves 13 are preferably also designed as spirals.
Likewise advantageously, the disk-shaped base body 4 has a first connecting element 14 for connecting a tool for fixing the edge tape 2 to the receiving element 1. This first connecting element 14 is advantageously designed such that it can additionally serve as a bearing element for the rotatable mounting of the receiving element 1. Furthermore, the inner clamping device 3 advantageously has a second connecting element 15, which in the example shown is arranged on the rotary element 8, for connecting the tool to the receiving element 1. The tool can thus be attached to the first connecting element 14 and—using the first connecting element 14 as a fulcrum—cause the rotary movement of the rotary element 8 via the second connecting element 15.
Finally, the exemplary receiving element 1 according to the invention preferably has a fixing element 16. This can be, for example, a screw which presses the rotary element 8 against the base body 4 and thus generates a frictional connection to prevent the rotary movement of the rotary element 8 relative to the base body 4. In this way, a secure fixation of the inner clamping device 3 can be ensured. In the example shown, the interlocking grooves 13 advantageously provide for a positive locking of the clamping elements 5 on the base body 4 when the rotary element 8 is fixed on the base body 4 by the fixing element 16.

Claims

1. An edge tape cassette for receiving edge tapes comprising a cassette housing (18), in which a winding core is arranged, which fixedly holds an edge tape (2), that is existent as a container in the form of a wound-up roll,

wherein

the edge tape cassette additionally has a receiving element (1) which is rotatably mounted in the edge tape cassette and on which the winding core is attached, in particular in a detachable manner.

2. The edge tape cassette according to claim 1,

wherein

the winding core is attached to one side of the receiving element (1).

3. The edge tape cassette according to claim 1,

wherein

the receiving element (1) has a base body (4) that is at least substantially disk-shaped, preferably at least substantially rotationally symmetrical.

4. The edge tape cassette according to claim 1,

wherein

the winding core is connected in a rotationally fixed manner to the receiving element (1), at least part of the receiving element (1) extending radially beyond the radial extension of the winding core from its axis of rotation.

5. The edge tape cassette according to claim 4,

wherein

the container abuts the receiving element (1) at least partially.

6. The edge tape cassette according to claim 3,

wherein

the winding core comprises an inner clamping device (3) which is designed to exert outward forces on an inward-facing surface (17) of the container.

7. The edge tape cassette according to claim 1,

wherein

the receiving element (1) has a bearing element (10) for rotatable mounting of the receiving element (1).

8. The edge tape cassette according to claim 6,

wherein

the inner clamping device (3) has a plurality of clamping elements (5), in particular acting in the manner of clamping jaws, which can be clamped for fixing the wound-up edge tape (2) against the inwardly facing surface (17) of the container.

9. The edge tape cassette according to claim 8,

wherein

the tensioning elements (5) on the base body (4) for fixing the edge tape (2) are each slidably guided along a tensioning direction (X) which has at least one radial component based on the disk-shaped extension of the base body (4), in particular wherein the clamping direction (X) is at least substantially oriented in the radial direction with respect to the disk-shaped extension of the base body (4).

10. The edge tape cassette according to claim 8,

wherein

the inner clamping device (3) has a rotary element (8), preferably arranged centrally on the disk-shaped base body (4), for fixing the edge tape (2), wherein the inner clamping device (3) is designed in such a way that rotation of the rotary element (8) relative to the disk-shaped base body (4) causes the edge tape (2) to be fixed, in particular wherein the clamping elements (5) are displaced along their respective clamping direction (X) by means of the rotation of the rotary element (8).

11. The edge tape cassette according to claim 10,

wherein

the disk-shaped base body (4) has a first connecting element (14) and/or the rotary element (8) has a second connecting element (15) around the edge tape (2) for fixing the receiving element (1).

12. The edge tape cassette according to claim 10,

wherein

the receiving element (1) has a fixing element (16) for fixing the rotary element (8) relative to the base body (4), in particular wherein the fixing element (16) is designed in such a way that it brings about a non-positive prevention of rotation of the rotary element (8) relative to the base body (4).

13. The edge tape cassette according to claim 3,

further comprising

a braking device (24) for braking a rotation of the receiving element (1) and/or a locking device for blocking the rotation of the receiving element (1) and/or an acceleration device (19, 20, 22) for accelerating a rotation of the receiving element (1), which preferably engages the base body (4) in the region of the outer edge of the base body (4).

14. The edge tape cassette according to claim 1,

wherein

the end of the edge tape lying on the winding core is connected to the winding core, in particular clamped or glued.

15. The edge tape cassette according to claim 1,

further comprising

an exit point at which the free end of the edge tape (2) can be withdrawn from the cassette.

16. The edge tape cassette according to claim 15,

wherein

the edge tape (2) extends laterally at the exit point in the region of its narrow sides.

17. The edge tape cassette according to claim 1,

further comprising

a clamping apparatus (23) for clamping the free end of the edge tape (2).

18. The edge tape cassette according to claim 17,

wherein

the clamping apparatus (23) is designed such that the clamping action with respect to the edge tape (2) can be canceled again.

19. The edge tape cassette according to claim 17,

wherein

the clamping apparatus (23) is arranged, in particular on the inside of the cassette housing (18), in the region of the exit of the edge tape from the cassette housing, in particular adjacent to an exit point at which the free end of the edge tape (2) can be withdrawn from the cassette.