Joint and a device for joining fiber web ends

Abstract

A joint and device for joining ends of at least two fiber webs together, the joint being formed of at least one cut provided to penetrate through the ends of the fiber webs in an overlapping position, which cut has at least one side part and from the side part extending at least one substantially straight part and which cut, which forms at least one flap, being configured to remain attached to the fiber webs by at least one folding line substantially aligned with the direction of the movement of the fiber webs. The device comprises a tool with a cutting edge and a counter element with a groove and located on the opposite side of the fiber webs, and the tool protrudes into the groove. The groove has a greater cross-sectional area than the cross-sectional area of the tool such that a loose and spacey fitting is provided.

Claims

1. Joint for joining ends of at least two fiber webs together, in which the joint is configured to be formed of at least one cut provided to penetrate through the ends of the fiber webs in an overlapping position, which cut has at least one side part and from the side part extending at least one substantially straight part and which cut forms at least one flap, which is configured to remain attached to the fiber webs attached by at least one folding line, which folding line of the flap is substantially aligned with the direction of the movement of the fiber webs, the cut having a corner form in the direction of the movement of the fiber webs formed in the meeting location of a side part of the cut and the folding line configured to form a carrying part of the joint.

2. Joint according to claim 1, wherein the tension of the fiber webs is configured to tighten the joint due to the tensions of the fiber webs in respect of each other.

3. Joint according to claim 1, wherein the cut has two opposite arched side parts and between the side parts extending substantially straight part and two flap parts are formed to the cut, which flap parts, are separated from each other by the between the side parts extending substantially straight part and remain attached to the fiber webs by the fold lines.

4. Joint according to claim 1, wherein several cuts are provided for the ends of the fiber webs to be joined.

5. Joint according to claim 1, wherein the joint has no adhesive or tape used to join the ends of the fiber webs.

6. Joint according to claim 1, wherein the fiber webs are pulp webs.

7. Device for joining ends of fiber webs together, which device comprises a tool with a cutting edge configured to provide a cut to the ends of the fiber webs and a counter element with one of a groove or an opening or an elastic surface part, which tool is located on one side of the fiber webs and the counter element is located on the opposite side of the fiber webs in respect of the tool, in which the one of the groove or the opening or the elastic surface part are positioned such that when the tool penetrates through the fiber webs, the tool protrudes into the one of the groove or the opening or the elastic surface part of the counter element, which one of the groove or the opening of the counter element has a greater cross-sectional area than the cross-sectional area of the tool or the elastic surface part of the counter element yields such that a loose and spacey fitting is provided, the cutting edge of the tool having a form that is configured to create a corner form of the cut in direction of the movement of the fiber webs configured to form a carrying part of a joint joining the ends of the fiber webs.

8. Device according to claim 7, wherein the device comprises a holder for holding and guiding the fiber webs.

9. Device according to claim 8, wherein the holder is connected to the tool and movable with the tool.

10. Device according to claim 8, wherein the holder is independently movable.

11. Device according to claim 8, wherein the counter element comprises a hold surface located opposite to the holder at the opposite side of the fiber webs in respect of the holder and that the fiber webs are configured to be held between the hold surface and the holder.

12. Device according to claim 7, wherein the tool has at least one opening edge for opening the cut in the fiber webs.

13. Device according to claim 7, wherein the device is located in an unwinder of a slitter-winder.

14. Device according to claim 7, wherein the device is located in an unwinder for pulp webs.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Aspects of the invention, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of some example embodiments when read in connection with the accompanying drawings and in the following the invention is described in more detail referring to the accompanying drawing, in which

[0044] in FIG. 1A is schematically shown a side view of an advantageous example of a device providing joint for joining fiber web ends with the tool of the device in resting position,

[0045] in FIG. 1B is schematically shown a side view of an advantageous example of a device providing joint for joining fiber web ends with the tool of the device in protruding position,

[0046] in FIG. 2 is schematically shown as view in surface level of a fiber web an advantageous example of a device providing joint for joining fiber web ends with a counter element provided with grooves,

[0047] in FIGS. 3A-3C is schematically shown views of an advantageous example of a tool of the device providing joint for joining fiber webs,

[0048] in FIGS. 4A-4B is schematically shown views of an advantageous example of a joint for joining fiber webs during formation of the joint,

[0049] in FIGS. 5A-4B5B is schematically shown views of an advantageous example of a joint for joining fiber webs during overlap formation of the joint,

[0050] in FIGS. 6A-6F is schematically shown advantageous examples of a tool of a device and a joint form for joining fiber web ends,

[0051] in FIG. 7 is schematically shown advantageous examples of a cut for a joint for joining fiber web ends and

[0052] in FIGS. 8A-8B is schematically shown some examples of variations of the groove or opening of a counter element of a tool of a device for joining fiber web ends.

DETAILED DESCRIPTION

[0053] During the course of the following description like numbers and signs will be used to identify like elements according to the different views which illustrate the invention and its advantageous examples. In the figures some repetitive reference signs have been omitted for clarity reasons.

[0054] In the example of FIGS. 1A-1B shown example of a device comprising a tool 10 and a counter element 20 providing joint for joining ends of fiber webs 15, 16. The direction S of the movement of the fiber webs 15, 16 is shown by the corresponding arrow. The device also comprises a holder 12A; 12B for holding and guiding the fiber webs 15, 16. In the FIGS. 1A-1B is shown two types of holder, in the figures the lower holder 12A is moving with the tool 10 and the upper holder 12B is not moving with the tool 10 but instead independently movable. During the joining of the ends of the fiber webs 15, 16 the upper holder 12B is in contact with the surfaces of the fiber webs and thus, holding and guiding the fiber webs 15, 16 all through the joining. The lower holder 12A moves with the tool 10 and thus holds and guides the fiber webs 15, 16 during punching of the fiber webs 15. 16. The counter element 20 of the device comprises a groove 13 or like opening at least for each tool 10. The counter element 20 may also comprise an elastic surface. The tool 10 is located on one side of the fiber webs 15, 16 and the counter element 20 is located on the opposite side of the fiber webs 15, 16 in respect of the tool 10. The grooves 13 are positioned such that when the tool 10 punches through the fiber webs 15, 16 the tool 10 protrudes into the groove 13 or the opening of the counter element 20 or the elastic surface of the counter element 20 yields as the tool 10 punched through the fiber webs 15, 16. The counter element 20 also comprises a hold surface 14 located opposite to the holder 12A, 12B at the opposite side of the fiber webs 15, 16 in respect of the holders 12A, 12B.

[0055] In FIG. 1A the tool 10 is in its resting position at a distance from the fiber webs 15, 16.

[0056] In FIG. 1B the tool 10 has penetrated and punched through the fiber webs 15, 16 to the corresponding groove 13 of the counter element 20 providing a cut to the fiber webs 15, 16. The holder 12A; 12B are holding the fiber webs 15, 16 against the corresponding hold surface 14 of the counter element 20.

[0057] In FIG. 2 is shown the fiber webs 15,16 and the device from above as can be noted the groove 13 is spacey in view of the tool 10 providing the cut 17 to the fiber webs 15, 16.

[0058] In FIGS. 3A-3C is shown an example of the tool 10 of the device providing joint for joining ends of the fiber webs 15, 16 and in FIGS. 4A-4B is shown an example of a joint for joining fiber webs during formation of the joint. The tool 10 has at least one cutting edge 19 creating the cut 17 to the fiber webs 15, 16 during penetrating and punching through the fiber webs 15, 16. The tool 10 also has at least one opening edge 22 for opening the cut 17 in the fiber webs 15, 16 while penetrating through the fiber webs 15, 16. The penetrating end of the tool 10 is in this example formed to have a substantially towards penetrating direction tapered form such, that at the first contacting part a substantially sharp edge line is formed, which may be towards the tool 10 curved, and that from ends of the first contacting, top sharp edge line away from the sharp edge line extending curved sharp side edge lines are formed and between the curved sharp side edge lines extending opening line 22 is provided. The tool 10 creates to the fiber webs 15, 16 the cut 17 with folding lines 18. The cut 17 has two opposite arched parts, corresponding to the sharp side edge lines of the tool 10 and between the arced parts extending substantially straight part, corresponding to the top sharp edge line of the tool 10. When the opening edge 22 penetrates the fiber webs 15,16 the cut 17 opens along the folding lines 18. The cut 17 also has a corner form 21, which forms the carrying part of the joint. In this example two flap parts 23 are formed to the cut 17, which flap parts 23, are separated from each other by the between the arced parts extending substantially straight part and remain attached to the fiber webs 15, 16 by the fold lines 18.

[0059] As can be seen from the FIGS. 5A-5B the cut 17 is created as an overlapping joint through the fiber webs 15,15 during penetrating a punching by the tensions of the fiber webs 15, 16 such that the actual cut 17 in each fiber web 15; 16 is slightly distanced, the flap parts 23 slightly overlapping. The distance is 0.1-10mm, advantageously 0.5-2mm, depending on the thicknesses of the fiber webs to be joined.

[0060] The joint and the device are configured to join an end of one fiber web 15 to an end of another fiber web 16 such, that the fiber webs 15, 16 are joined by a form-fitting joint and the one of the fiber webs 15;16 pulls the other fiber web 16; 15 with desired tension and speed to desired location overlapping position. The device comprises the tool 10, which tensioned position of the fiber webs 15, 16, is protruded against counter element 20. Alternatively, the tool 10, while the fiber webs 15, 16 are moving in a same direction, is protruded against the counter element 10. The counter element 20 is provided with a groove 13 or opening with greater area than the respective tool 10. The tool 10 is configured to penetrate through the overlapping ends of the fiber webs at the location of the respective groove 13 or opening of the counter element 20. Thus, the tool 10 is also provided to protrude into the respective groove 13 or opening of the counter element 20. The cutting edge 19 of the tool 10 is configured to cut material of the ends of the fiber webs 15, 16 while penetrating and additionally at final stage of the penetrating open partially the cuts of the overlapping ends of the fiber webs by the opening edge 22. The shape of the groove 13 or opening of the counter element 20 can be different from the shape of the cutting form of the tool 10. Thus, the cutting edge 19 of the tool 10 cuts the desired cutting form while penetrating through the tensioned fiber webs 15, 16 against the counter element 20. The tool 10 of the device is configured to open the cut 17 due to its protruding movement such, that the folding line 18 of the flap 23 is substantially aligned with the direction S of the movement of the fiber webs 15, 16. Thus, the joint holds immediately in the direction S of the movement of the fiber webs 15, 16. After the joint is finished the fiber webs 15, 16 tighten in respect of each other due to form of the cut 17 and the flap 23 as individual joints tighten the one and the other fiber webs 15, 16 in respect of each other due to the flaps 23 of the joint. The flap 23 is positioned in the direction S of the movement of the fiber webs 15, 16. The cutting edge 19 of the tool 10 has a form that creates the corner form 21, advantageously a curve or a barb cut, in direction S of the movement of the fiber web. This corner form 21 is configured to bond the overlap of the flaps 23 during tightening of the fiber webs 15, 16.

[0061] In FIGS. 6A-6C is shown some alternative examples of the tool 10 with respective cut 17 of symmetrical form and two flaps 23. The cutting edge 19 of the tool 10 is formed of at least the top edge part and the side edge parts with the opening part extending between the side edge parts. Thus, the cut 17 has the center cut formed by the top edge part and extending between the side cut parts formed by the side edge parts of the cutting edge 19. The folding lines 18 extends between the respective ends of the side cut parts and the flaps 23 are formed. In FIGS. 6D-6F is shown some examples of asymmetrical cuts 17 with one flap 23. Further in FIG. 7 is shown some examples of asymmetrical cuts with one flap 23 in the upper part of the figure positioned in different directions one after another and in the lower part of the figure positioned in different directions one below another.

[0062] In FIGS. 8A-8B is shown some examples of variations of the groove 13 or opening 13 of the counter element 20. In FIG. 8A is shown an example with less spacing, in which the beginning of the cutting is against sides of the opening 13. In FIG. 8B is shown an example with looser spacing and additionally showing groove 13 extending in the direction S of the movement of the fiber webs 15, 16.

[0063] In the description in the foregoing, although some functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain embodiments or examples, those features may also be present in other embodiments or examples whether described or not. Above the invention has been described by referring to some advantageous examples only to which the invention is not to be narrowly limited. Many modifications and alterations are possible within the invention as defined in the following claims.

[0064] Reference signs used in the drawing:

[0065] 10 tool

[0066] 12A, 12B holder

[0067] 13 groove

[0068] 14 hold surface

[0069] 15 end of one fiber web

[0070] 16 end of another fiber web

[0071] 17 cut

[0072] 18 folding line

[0073] 19 cutting edge

[0074] 20 counter element

[0075] 21 corner form

[0076] 22 opening edge

[0077] 23 flap part

[0078] P holding pressure

[0079] S direction of movement of fiber web