Machine for attaching a tag to an infusion bag using an intermediate knotted thread

• US 6,499,273 B1
• Filed: 05/05/2000
• Issued: 12/31/2002
• Est. Priority Date: 09/18/1998
• Status: Expired due to Term

• Current Assignee: IMA - Industria Macchine Automatiche SPA (Vacchi Family)
• Original Assignee: IMA - Industria Macchine Automatiche SPA (Vacchi Family)
• Inventors: Marzocchi, Paolo
• Primary Examiner(s): Smith, Scott A.
• Assistant Examiner(s): TRUONG, THANH K
• Application Number:
  US09/530,806
• Time in Patent Office: 970 Days
• Field of Search: 531/341, 531/342, 534/13, 493/226, 493/375, 493/376
• US Class Current: 53/413
• CPC Class Codes: B65B 29/04 Attaching, or forming and attaching, string handles or tags to tea bags

Abstract

An improved machine (1) for making filter bags (2) containing a product for infusion, with a pick-up tag (3) connected to the top (12) of the filter bag (2) by an intermediate thread (5), comprises a wheel (6) which rotates with a stepping motion about its own axis of rotation (16) and is equipped with grippers (7) which are brought into contact with a series of operating stations, comprising at least one station (9) for folding a tubular semi-finished product (20) containing the product for infusion, and at least one station (15) for knotting the thread (5). The machine (1) has thread (5) feed means (33, 34, 35) which operate on the thread (5) fed between consecutive pairs of the grippers (7) along the edge of the wheel (6) so as to prevent it from sliding backwards. The thread (5) knotting station (15) is equipped with needles (45) which have a first and second eye (51, 52) positioned at different distances from the point. The needles (45) are moved in such a way as to pick up the thread (5) with the second eye (52), forming a loop (62) in which the thread (5) is associated with the first eye (51), interceptor elements (54) being moved in time with the needles (45) so that they passe through the first eye (51), pushing a section of thread (5) through the loop (62). The invention also relates to a method for knotting the thread (5).

Claims

1. A machine for making filter bags containing a product for infusion, having a pick-up tag connected to the top of the filter bag by an intermediate thread, said machine comprising a wheel which rotates with a stepping motion about its own axis of rotation, being equipped with grippers, the wheel bringing the grippers into contact with a series of operating stations, comprising at least one station for folding a tubular semi-finished product containing the product for infusion, and at least one station for knotting the thread, the machine further comprising thread feed means which operate on the thread fed between pairs of the grippers positioned one after another along the edge of the wheel;

said feed means presenting a fork with extended teeth angled parallel with the axis of rotation of the wheel, the fork being supported by an arm which oscillates between a home position, in which the teeth are outside the wheel, and an operating position, in which the teeth are between two consecutive grippers on the wheel.

2. The machine according to claim 1, wherein one of the grippers between Which the feed means operate is positioned at the folding station for the tubular semi-finished product.

3. The machine according to claim 1, wherein the teeth have faces which meet at least at one shared vertex.

4. The machine according to claim 3, wherein said faces are flat.

5. The machine according to claim 1, wherein the feed means are designed to give the thread a segmented configuration between two consecutive grippers on the wheel.

6. The machine according to claim 5, wherein the segmented configuration envisages sections of thread angled in directions corresponding to the radii and chords of the wheel.

7. The machine according to claim 1, wherein the knotting station comprises a knotting device equipped with needles for knotting the thread to the tag and to the top of the filter bag, the needles being brought into contact with tag and bag-top stops and with respective mobile needle interceptor elements, wherein at least one of the needles has a first and a second eye, being located at different distances from the point, said at least one needle being moved in such a way as to pick up the thread with the second eye, forming a loop in which the thread is associated with the first eye, the interceptor element being moved in time with the needle so that it passes through the first eye, pushing a section of thread through the above-mentioned loop.

8. The machine according to claim 7, wherein the first and second eyes are located on two distinct transversal planes passing through the longitudinal axis of the needle.

9. The machine according to claim 8, wherein the transversal planes passing through the longitudinal axis of the needle and relative to the first and second eyes are at right-angles to one another.

10. The machine according to claim 7, wherein the knotting device comprises a single presser body for pressing the tag and the top of the filter bag against the stops.

11. The machine according to claim 10, wherein the presser body has faces which meet at a shared tip.

12. The machine according to claim 11, wherein the faces of the presser body are curved.

13. The machine according to claim 12, wherein the longitudinal cavity is open at the side.

14. The machine according to claim 10, wherein the knotting station comprises mobile pressure pads, being synchronised with the presser body, the pads comprising a support body to which first elastic plates are connected, being designed to interact with the interceptor element and clamp the thread between the first elastic plate and the interceptor element.

15. The machine according to claim 10, wherein the knotting station comprises mobile pressure pads, being synchronised with the presser body, the pads comprising a support body to which second elastic plates are connected, being designed to interact with the interceptor element and to allow the interceptor element and thread to pass through them, then to be disengaged from the interceptor element, holding the thread between the second elastic plate and the support body.

16. The machine according to claim 15, wherein the interceptor element is shaped like a fork and has two teeth, being positioned side by side and having longitudinally offset free ends;

corresponding with the alternative motion of the interceptor element, the first tooth, having the first free end which projects furthest, inserts itself between the second elastic plates of the pressure pads and the relative support body, separating them from the support body and vice versa;

the second tooth being designed to move back and forth between the second elastic plates and the support body in such a way that it draws and releases the thread there after the first tooth and subjects the second elastic plates to the minimum of stress.

17. The machine according to claim 16, wherein the second tooth has a projection designed to intercept the thread, being located on the side of the second tooth and set back from the free end.

18. The machine according to claim 7, wherein a longitudinal cavity passes through the stop elements, said cavity being shaped in such a way that the needles can pass through it.

19. The machine according to claim 7, wherein it comprises two interceptor elements, being located at variable distances from the axis of rotation of the wheel.

20. The machine according to claim 7, wherein it comprises air jet means whose activation allows sections of thread hanging in the space between the tag and the top of the filter bag to be gathered up.

21. The machine according to claim 1, wherein at least the first eye is open at the side.

22. The machine according to claim 1, wherein at least one needle rotates about their own longitudinal axes.

23. The machine according to claim 22, wherein the needle or needles rotate about their own longitudinal axes through an angle of at least 90°

.

24. The machine according to claim 22, wherein the needle or needles rotate about their own longitudinal axes through an angle of at least 180°

or multiples of said angle.

25. The machine according to claim 1, wherein at least one needle rotates through an angle whose size is such that it allows the thread to wind around itself and to determine a corresponding tensioning and tightening of the loop.

26. The machine according to claim 1, wherein the grippers have teeth with thread support elements, consisting of leaf spring elements designed to hold the thread, between themselves and the support elements.

27. A machine for making filter bags containing a product for infusion, having a pick-up tag connected to the top of the filter bag by an intermediate thread, said machine comprising a wheel which rotates with a stepping motion about its own axis of rotation, being equipped with grippers, the wheel bringing the grippers into contact with a series of operating stations, comprising at least one station for folding a tubular semi-finished product containing the product for infusion, and at least one station for knotting the thread, the knotting station comprising a knotting device having needles for knotting the thread to the tag and the top of the filter bag, the needles being brought into contact with stop elements for the tag and the top of the bag and with respective interceptor elements which are mobile relative to the needles, at least one of the needles presenting a first and second eye, being located at different distances from the point, the needle or needles being moved in such a way as to pick up the thread with the second eye, forming a loop in which the thread is associated with the first eye, the interceptor element being moved in time with the needle so that it passes through the first eye, pushing a section of thread through the loop;

the knotting device comprising a single presser body for pressing the tag and the top of the filter bag against the stops, said presser body having faces which meet at a shared tip.

28. The machine according to claim 27, wherein in the first and second eyes are located in two distinct transversal planes passing through the longitudinal axis of the needle.

29. The machine according to claim 28, wherein the transversal planes passing through the longitudinal axis of the needle and relative to the first and second eyes are at right-angles to one another.

30. The machine according to claim 28, wherein at least the first eye is open at the side.

31. The machine according to claim 28, wherein the needle or needles rotate about their own longitudinal axes.

32. The machine according to claim 31, wherein the needle or needles rotate about their own longitudinal axes through an angle of at least 90°

.

33. The machine according to claim 31, wherein the needle or needles rotate about their own longitudinal axes through an angle of at least 180°

or multiples of said angle.

34. The machine according to claim 27, wherein the needle or needles rotate through an angle whose size is such that it allows the thread to wind around itself and to determine a corresponding tensioning and tightening of the loop on the needle.

35. The machine according to claim 34, wherein the longitudinal cavity is open at the side.

36. The machine according to claim 27, wherein the faces of the presser body are curved.

37. The machine according to claim 27, wherein a longitudinal cavity passes through the stop elements, said cavity being shaped in such a way that the needles can pass through it.

38. The machine according to claim 27, wherein the grippers have teeth with thread support elements, consisting of leaf spring elements designed to hold the thread, between themselves and the support elements.

39. A method for making filter bags containing a product for infusion, having a pick-up tag connected to the top of the filter bag by knotting an intermediate thread, the method comprising stages for forming a loop in the thread using at least one needle, the latter having a first and second eye, being located at different distances from the point, and moved in such a way as to pick up the thread with the second eye, associating it with the first eye;

winding the thread about itself and angling the loop relative to an interceptor element, being moved in time with the needle so that it passes through the first eye, pushing a section of thread through the loop;

the method further comprising a stage during which, after passing through the loop, the thread is held between a thread interceptor element and a support body having an elastic plate which can be brought into contact with the interceptor element, holding the thread between the two.

40. The method according to claim 39, wherein it comprises a further stage during which the thread is held, between a second elastic plate and a support body and a stage during which a knot in the thread is tightened by moving the support body away from the wheel.

41. The method according to claim 39, wherein it comprises a stage during which the thread is gathered between the tag and the filter bag, following tightening of the knot.

42. The method according to claim 45, wherein the gathering stage is effected by air jet means, being designed to act upon hanging sections of thread.