WO2002083540A1

WO2002083540A1 - Method and device for arranging a knot in a cord, device for buffering and distributing cord loops and assembly of such devices

Info

Publication number: WO2002083540A1
Application number: PCT/NL2002/000234
Authority: WO
Inventors: Rudolf Johannes Gerardus Antonius Van Der Hoorn
Original assignee: Budev B.V.
Priority date: 2001-04-11
Filing date: 2002-04-10
Publication date: 2002-10-24
Also published as: NL1017822C1

Abstract

The invention relates to a method for arranging a knot in at least one cord, comprising the steps of: a) carrying by means of a gas pressure difference a free cord part through a channel which is pre-formed as a loose knot and has a channel wall completely enclosing the channel, b) opening the channel in axial direction over the whole length, and c) releasing the cord from the channel while retaining the knot arranged in the cord. The invention also relates to a device for performing such a method, as well as to a device for buffering and distributing cord loops.

Description

Method and device for arranging a knot in a cord, device for buffering and distributing cord loops and assembly of such devices

The device relates to a method and device for arranging a knot in at least one cord. The invention also relates to a device for buffering and distributing cord loops, as well as to an assembly of such a device with the device for arranging a knot.

Mechanized knotting of cord, string, thread, cable or other flexible and elongate material is for instance known from mechanical knotting devices wherein use is made of displaceable clamps, pincers, needles and the like. The drawbacks of such mechanical knotting devices are, among others, that they have a relatively complex structure, require much maintenance and have a limited production speed. A pneumatic knotting device also exists, known from US 3,868,133, in which a cord is carried through an opened guide with an airflow. After the knot has been made it can be removed from the guide in simple manner. Such a device has the drawbacks, among others, that the knotting takes place in less controlled manner, that a large quantity of air is required to displace the cord, with the associated drawbacks of a high energy consumption and an impact (via noise among other things) on the environment, and that the device is only suitable for knotting very flexible and light materials.

The present invention has for its object to provide an improved device for knotting cord or the like in pneumatic manner with which it is possible to work in a controllable and effective manner. It is also an object to embody such a device such that cord loops can hereby be made which can be further processed in mechanized or automated manner.

The invention provides for this purpose a method for arranging a knot in at least one cord, comprising the steps of: a) carrying by means of a gas pressure difference a free cord part through a channel which is pre-formed as a loose knot and has a channel wall completely enclosing the channel, b) opening the channel in axial direction over the whole length, and c) releasing the cord from the channel while retaining the knot arranged in the cord. The position of the cord, or a comparable flexible and elongate material such as a cord, string, thread or cable, can be controlled by means of this method. The cord can after all not leave the channel at an undesired position. Another significant advantage is that the required gas displacement can be realized by means of an overpressure or underpressure to be applied on one side, and that the gas flow does not decrease, or hardly so, while running through the channel, since mixing with the ambient atmosphere is not possible. For a controllable positioning of the knot in the cord, the cord is preferably fixed at least on one side during processing step a). The position at which the knot is arranged in the cord can thus be determined. Partly because of the limited number of moving parts and the controllable gas flow, the method according to the present invention can be performed at high speed. When two or more cords are carried through the channel simultaneously according to the present method, they can thus be knotted together.

In order to arrange a cord loop bounded by a knot, in a preferred application of the method at least one free cord part is also carried during processing step a) through a channel part connecting onto the channel pre-formed as a loose knot, and at least two free cord parts are carried through the channel pre-formed as a loose knot. Using the channel part a cord part is buffered which remains free after making of the knot and thus forms a loop. The length of a loop to be produced is determined in simple manner by varying the length of the channel part. The loop is closed by connecting at least two free cord parts by means of a knot. Such a method is very simple and can be carried out at great speed.

In order to perform processing step a), in a particular preferred application of the method an object for fastening to the cord loop and having a continuous opening is placed in an interruption arranged for this purpose in the channel part, such that the channel walls more or less fit onto the object. As object can for instance be envisaged a card, brochure or advertising matter with an opening through which a cord loop can be arranged in this automated manner.

For the purpose of fixing the knot released according to processing step c) the knot is preferably tightened. This is possible for instance by clamping a part of the cord (such as an end) with a determined clamping force and then pulling the cord with the knot arranged therein free from this clamping. The maximum required pulling force depends on the force with which the cord is clamped, so that the force with which the knot is tightened is hereby also maximized. For further processing of a cord loop made by means of the above described method, it is recommended to wholly or partially maintain the controlled orientation of a cord loop during the making thereof in the further processing of such a loop. It is recommended for this purpose that a manufactured cord loop is positioned following the release from the channel part and/or buffered on a holder.

When the free cord part is an end of a buffered cord, this end is preferably separated from the cord buffer so that a further separating processing of the cord part provided with a knot is possible.

The invention also provides a device for arranging a knot in at least one cord, comprising: a channel which is pre-formed as a loose knot and which is provided over the length with a closable continuous opening, means for gas displacement for creating a gas flow through the channel entraining at least one cord, and supply means for a cord. Using this device the advantages can be realized as already described with reference to the method according to the invention.

In order to make a cord loop, a preferred embodiment of the device is provided with a channel part connecting onto the channel pre-formed as a loose knot, which part more preferably has an adjustable length so as to thus also enable varying of the length of the cord loop. When in yet another preferred embodiment the connecting channel part is provided with an interruption in the channel wall for passage of a part of an object provided with an opening and for fastening to the cord such that the interruption in the channel wall is at least substantially fully closed by the object, such an object can then be placed "in" the transport path of the cord. The object thus forms a part of the channel wall of the connecting channel part. A close fit of the object to the connecting channel part is desirable to prevent pressure loss and to minimize the chance of the cord coming out of the channel.

In a favourable embodiment variant of the device according to the invention the channel is arranged in at least two mutually connecting forming parts, and the channel is situated on the contact surfaces of the forming parts such that when the forming parts are connected the channel has a completely enclosing wall and that when the forming parts are moved apart the channel is opened over the whole length. Such a channel can be manufactured relatively simply, for instance by milling the channel passage in the contact sides of the forming parts. In addition, it is relatively simple to open the channel in axial direction along the whole length; only the forming parts have to be moved apart for this purpose. Where channel parts in the connecting forming parts cross each other, a displaceable separating element is preferably arranged. By means of the separating element a separation can be made at a position where the channel passages of two forming parts come to lie on each other. To make a simple knot the channel passage must for instance already cross at least twice, which can impede a desired gas flow through the channel (instead of running through the whole knotting path the gas flow can choose a shorter path at "junctions", whereby a part of the whole channel is

"bypassed"). In order to now still guarantee that the gas flow runs through the whole channel, a separating element can be arranged which realizes a more or less gastight separation at a junction in the channel. This separating element moreover ensures guiding of the cord in the desired direction.

As stated above, at least two junctions of the channel arranged in the contact sides of the forming parts are already required for a simple knot. Even more junctions are required for more complex knots. This means that at least two separating elements are generally also required. To enable opening of the channel along the whole axial length, and to thus release the manufactured knot with or without cord loop, it is necessary that the separating elements can also be moved a distance from the channel. This displacing of the separating elements relative to the forming parts can be mechanized by coupling them to drive means. Displacing of a plurality of separating elements can be readily synchronized by joining together a plurality of separating elements.

In yet another preferred embodiment the supply means for cord comprise a cord buffer and the device is provided with separating means for separating a desired cord length from the buffer. The cord for processing can thus be separated from a bobbin, roll or the like, whereby a simple supply of cord or similar material is possible. For a controlled discharge of processed cord, such as knotted cord loops, the device can be provided with at least one supply holder for holding cord loops coming from the channel.

The invention also provides a device for buffering and distributing cord loops, comprising a mandrel for receiving at least one cord loop and blowing means for displacing the cord loop over the mandrel. In a preferred embodiment of such a buffering and distributing device the mandrel is conical and the blowing means are adapted to lead blow air along the mandrel by means of a Coanda effect. Such a device has a simple construction, can be assembled with a knotting device as described above without problem, and is reliable in use.

Finally, the invention provides an assembly of a knotting device according to the invention and a buffering and distributing device as described above, wherein the mandrel of the buffering and distributing device connects to the knotting device such that a cord loop released from the knotting device is engaged by the mandrel.

The present invention will be further elucidated on the basis of the non-limitative embodiments shown in the following figures. Herein: figure 1 shows a perspective view of a device for arranging a knot in a cord according to the invention, figure 2 is a perspective view of an alternative embodiment of the device shown in figure 1, figure 3 a is a perspective view of a part of a third embodiment of a device for arranging a knot in a cord according to the invention in an active position, and figure 3b is a perspective view of the part of the third embodiment of the device shown in figure 3 a in an opened position.

Figure 1 shows a device 1 for arranging a knot in a cord (not shown). Device 1 consists of two forming parts 2,3, in the common contact sides 4,5 of which a knot-shaped channel 6 is recessed. The knot-shaped channel 6 is herein arranged in contact sides 4,5 such that it is opened over the whole (axial) length. At two positions a part of the channel 6 arranged in one of the forming parts 2 crosses a part of the channel 6 arranged in the other forming part 3. Displaceable separating elements 7,8 in the form of blades are provided at these positions. Separating elements 7,8 are joined together to a rigid whole by a bridge construction 9 such that they can only be moved synchronously.

Forming parts 2,3 and the integral separating elements 7,8 are assembled by means of a pivot shaft 10 so that device 1 can be opened and closed in simple manner. During use the device 1 is closed and a gas flow is generated through channel 6. On for instance the non- visible side of upper forming part 3 a cord is guided through a feed opening close to position 11 and into the channel. Due to gas flow (by applying underpressure or overpressure to one side of channel 6) the cord will be carried through channel 6 until it reaches an exit 12 of channel 6. The gas flow can now be stopped and the (still loose) knot can be removed after opening of device 1 (moving apart forming parts 2,3 and the assembly of separating elements 7,8).

Figure 2 shows an alternative device 13 in which a channel part 15 with which a cord loop can be formed connects onto a knot-shaped channel 14. Connecting channel part 15 also arranges a cord by means of a gas pressure difference. Arranged in connecting channel 15 more or less perpendicularly thereof is an interruption 16 in which a label with an opening can for instance be placed. An object can thus be fastened to the cord loop. When connecting channel 15 is provided with means with which the length of channel 15 can be adjusted (telescopic construction, segmented construction with removable parts and so on), the length of a cord loop to be manufactured can be varied. Such a device 13 can for instance be applied to make cord loops with attached label, which are for instance fastened to the neck of a bottle. Also pointed out are slidable separating elements 17,18,19 which form part of device 13 and differ from the pivotable separating elements 7, 8 as shown in figure 1.

Figure 3 a shows yet another embodiment of a knotting device 20 according to the invention with a knot-shaped channel 21, relative to which separating elements 22,23 are displaceable by means of cylinders 24,25. Device 20 is also provided with a holding element 26, the function of which is described with reference to figure 3b.

In figure 3b the knotting device 20 is opened and separating elements 22,23 are retracted by cylinders 24,25, such that they lie clear of knot-shaped channel 21. Holding element 26 is displaced by rotating a turntable 27 so that a cord part is clamped with a controllable force. Because of the clamping a determined force must be produced when removing a knot until the clamping force is overcome. The force required to remove the knot determines how tight a knot is pulled, so that holding element 26 indirectly determines the degree of tightening of the knot. Although the invention is elucidated with reference to only a few embodiments, it will be apparent to all that the invention is by no means limited to the described and shown embodiments. On the contrary, many more variations are still possible for the skilled person within the scope of the invention. The options for use of the invention are countless. In addition to the already stated applications, it is for instance also possible to knot cord in the tampon industry, in the manufacture of netting and so on.

Claims

1. Method for arranging a knot in at least one cord, comprising the steps of: a) carrying by means of a gas pressure difference a free cord part through a channel which is pre-formed as a loose knot and has a channel wall completely enclosing the channel, b) opening the channel in axial direction over the whole length, and c) releasing the cord from the channel while retaining the knot arranged in the cord.

2. Method as claimed in claim 1 , wherein the cord is fixed at least on one side during processing step a).

3. Method as claimed in claim 1 or 2, wherein at least one free cord part is also carried during processing step a) through a channel part connecting onto the channel pre-formed as a loose knot, and at least two free cord parts are carried through the channel pre-formed as a loose knot for the purpose of arranging in the cord a cord loop bounded by the knot.

4. Method as claimed in claim 3, wherein for the purpose of performing processing step a), an object for fastening to the cord loop and having a continuous opening is placed in an interruption arranged for this purpose in the channel part, such that the channel walls more or less fit onto the object.

5. Method as claimed in claim 4, wherein the length of the channel part for forming a cord loop is adjusted such that a thus made loop has a desired length.

6. Method as claimed in any of the foregoing claims, wherein the knot released according to processing step c) is pulled such that the knot becomes tighter.

7. Method as claimed in any of the claims 3-6, wherein a manufactured cord loop is buffered on a holder following release from the channel part.

8. Method as claimed in any of the foregoing claims, wherein the free cord part is an end of a buffered cord, which free cord part is separated from the buffered cord.

9. Device for arranging a knot in at least one cord, comprising:

- a channel which is pre-formed as a loose knot and which is provided over the length with a closable continuous opening, - means for gas displacement for creating a gas flow through the channel entraining at least one cord, and

- supply means for a cord.

10. Device as claimed in claim 9, wherein a channel part connects onto the channel pre-formed as a loose knot for the purpose of forming a cord loop.

11. Device as claimed in claim 10, wherein the length of the connecting channel part is adjustable.

12. Device as claimed in claim 10 or 11, wherein the connecting channel part is provided with an interruption in the channel wall for passage of a part of an object provided with an opening and for fastening to the cord such that the interruption in the channel wall is at least substantially fully closed by the object.

13. Device as claimed in any of the claims 9-12, wherein the channel is arranged in at least two mutually connecting forming parts, and the channel is situated on the contact surfaces of the forming parts such that when the forming parts are connected the channel has a completely enclosing wall and that when the forming parts are moved apart the channel is opened over the whole length.

14. Device as claimed in claim 13, wherein a displaceable separating element is arranged at the position where channel parts in the connecting forming parts cross each other.

15. Device as claimed in claim 14, wherein a plurality of separating elements are joined together.

16. Device as claimed in claim 14 or 15, wherein the separating elements are coupled to drive means for mechanized displacement of the separating elements.

17. Device as claimed in any of the claims 9-16, wherein the supply means for cord comprise a cord buffer and the device is provided with separating means for separating a desired cord length from the buffer.

18. Device as claimed in any of the claims 9-17, wherein the device is provided with at least one supply holder for holding cord loops coming from the channel.

19. Device for buffering and distributing cord loops, comprising a mandrel for receiving at least one cord loop and blowing means for displacing the cord loop over the mandrel.

20. Device as claimed in claim 19, wherein the mandrel is conical and the blowing means are adapted to lead blow air along the mandrel by means of a Coanda effect.

21. Assembly of a knotting device as claimed in any of the claims 10-18 and a buffering and distributing device as claimed in claim 19 or 20, wherein the mandrel of the buffering and distributing device connects to the knotting device such that a cord loop released from the knotting device is engaged by the mandrel.