WO2002040251A2

WO2002040251A2 - Zipper lock profile feed control mechanism

Info

Publication number: WO2002040251A2
Application number: PCT/US2001/048366
Authority: WO
Inventors: Gerhard Kuss; Siegfried Wulsch; Torsten Nicolai
Original assignee: Rovema Packaging Machines L.P.
Priority date: 2000-11-03
Filing date: 2001-10-30
Publication date: 2002-05-23
Also published as: WO2002040251A3; AU2002230850A1

Abstract

A method of feeding a selected length of a resiliently flexible plastic profiled recloseable fastener strip from a reel containing a continuous length thereof transversely to an elongate length of web material for securement thereto.

Description

ZIPPER LOCK FEED CONTROL MECHANISM FIELD OF THE INVENTION This invention relates to a method for feeding a selected length of a resiliently flexible profiled recloseable fastener strip from a reel containing a continuous length thereof transversely to an elongate length of web material

BACKGROUND OF THE INVENTION It is known from U.S. Patent Nos. 4 655 862 and 4 909 017 to feed a resiliently flexible plastic profiled recloseable fastener strip, hereinafter sometimes referred to as a "zipper" or "zipper strip", from a reel containing a continuous length thereof transversely to an elongate length of web material. However, these patents do not reveal the difficulty that is incurred when the system is to be adjusted to accommodate a different length of zipper and/or to accommodate a different width of web material. Generally, the system utilizes an adjustably positionable cutter station combined with different length zipper guide tracks for guiding the cut zipper lengths from the cutter station to the position whereat they are to be individually attached or tacked to the web material. The feed motor controlling the movement of the strip and cut zipper lengths is set to feed a whole selected zipper length. Thus, the system cycles through a first cycle involving a feed of a whole zipper length, stop and cut while simultaneously a previously cut to length strip of zipper in the zipper guide track is sealed or tacked to the web material, followed by a second cycle also involving a feed of a whole zipper length, stop and cut while simultaneously a previously cut to length strip of zipper in the zipper guide track is sealed or tacked to the web material and so on. A system which enables quick change-overs to different zipper lengths and without necessitating an adjustment of the position of the cutter station relative to the location of the web material and/or a replacement of a zipper guide track for the various cut zipper lengths is highly desirable.

SUMMARY OF THE INVENTION The objects and purposes of the invention have been met by providing a method of feeding a selected length of a resiliently flexible plastic profiled recloseable fastener strip from a reel containing a continuous length thereof transversely to an elongate length of web material for securement thereto, comprising the steps of: orienting during set up a cutter member of a cutting station a predetermined distance from a longitudinal center line of the web material and orienting an initial first length of the resilient flexible plastic profiled recloseable fastener strip directly from the reel intermittent the cutting station and the center line of the web material; and thereafter advancing a second length of the strip past the cutter station and thence cutting the strip during a time that the strip is not being advanced, followed immediately by a further advancing of a length of the strip equal to the first length past the cutting station and activating a tack or seal of a strip to the web material whereby the initial first length and the second length have a combined length equal to the selected length. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of the zipper attachment or tacking system for performing the method of this invention; Figure 2 is a schematic diagram illustrating the initial set up positions;

Figure 3 is a schematic diagram of the individual zipper lengths lined up on the zipper guide track following a feed toward the web material of a partial length of zipper material, stop and cut;

Figure 4 is a view like Figure 3, but illustrating the zipper material having been advanced a partial distance for causing a zipper piece to straddle the center line for the web material and to become tacked or sealed to the web material thereat;

Figure 5 is a view like Figure 4, but illustrating the prior art methodology of feeding whole zipper lengths, stop, cut and seal or tack followed by a further feeding of whole zipper lengths; and

Figure 6 is a motion/time diagram involving the inventive methodology.

DETAILED DESCRIPTION U.S. Patent Nos. 4 655 862 and 4 909 017 are to be incorporated herein by reference.

As is depicted in Figure 1, a zipper installation station 10 includes a spool 11 of extruded resiliently flexible plastic profiled recloseable fastener 12 mounted in a conventional manner to be unwound therefrom by a drive mechanism 13 composed of a pair of mating drive wheels each having an annular groove in the periphery to accommodate the geometry of the recloseable fastener 12. The periphery of the drive wheels is also configured to engage each other and be driven at the same speed of rotation by a common servo drive motor 14. The material of the recloseable fastener 12 is oriented in a pinched manner between the drive wheels so that when the drive wheels are rotated, the recloseable fastener 12 will be drawn off the spool 11. A control circuit 16 is provided for sequentially controlling a first time interval or number of rotations that the drive motor 14 is driven, a second interval that the drive motor is stopped and to effect a cut, a third time interval or number of rotations that the drive motor is again operated and a fourth time interval that the drive motor is stopped and to effect a tack or seal of the zipper to the web material.

A cutter station 17 is provided for cutting the recloseable fastener into selected zipper lengths 18 before they are fed in the zipper guide track 19, extending between the cutter station 17 across the width of the web material 21, transversely to an elongate length of the web material 21. In the inventive method, the cutting member 22 of the cutter station 17 is oriented a predetermined fixed distance "X" from the center line A of the web material 19. An initial first length 23 of zipper is fed manually or by the drive motor 14 to an initial position illustrated in Figure 2 so that the leading end thereof is located intermittent the cutting member 22 and the center line A of the web material 19. Usually, a full length zipper piece 18A precedes the piece that is to be cut to length and no zipper piece straddles the center line A of the web material 21 as shown in Figure 2. The previous zipper strip 18C already tacked or sealed to the web material is shown in broken lines in Figures 2-4. After the aforesaid set up, the system is now ready for cyclic operation. More specifically, the control circuit 16 effects an activation of the drive motor 14 to effect an advance of zipper material 12 a partial distance 24 (see Figure 3) past the cutter member 22 until a full length 18B of zipper material is now past the cutter member 22 whereupon the control circuit 16 causes the drive motor 14 to become temporarily deactivated to halt the advancement of zipper material 12 toward the web material 21. Thereafter, the control circuit 16 causes the cutter member 22 of the cutter station 17 to become activated to cut the zipper material as depicted in Figure 3. Thereafter, the control circuit 16 again causes the drive motor 14 to become activated to effect an advance of the zipper material a partial distance 23 equal in length to the initial first length whereupon the control circuit 16 again halts the drive motor 14 to halt the advance of zipper material to permit a previously cut and advanced strip of zipper material 18A to straddle the center line A of the web material 21 and become sealed or tacked to the stationary web material 21 at this time and as depicted in Figure 4. Once the web material 22 is advanced by a web material drive mechanism 26, the web material 21 removes the zipper 18A now attached thereto to the position 18C in Figure 2 to empty the guide track section 19 to set up the receipt of a further strip 18B of zipper material in response to the next activation of the drive motor 14 by the control circuit 16.

The control circuit 16 is configured to facilitate an adjustment of the time interval or number of rotations of the drive motor 14 to allow for the partial length 24 to pass by the cutter member, the time interval for the stop to effect a cut (Figure 3) , the time interval or number of rotations of the drive motor 14 to allow for the initial length 23 of zipper material to pass by the cutter member following the cut and the time interval for operation for effecting a seal or tack of the zipper strip to the web material by the zipper tack/seal device 27. As a result, the initial first length 23 of zipper material can be controlled to, for example, 50% of the total length of the zipper or 40% or some other percentage so that the partial length 24 thereafter fed by the drive motor 14 will be equal in length to the balance of the selected length 18 of the zipper. This inventive zipper feed method does not require movement of the cutter station or substituting different zipper guide tracks in order to handle various length zipper pieces in case of different bag sizes.

Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.

Claims

What is claimed is:

1. A method of feeding a selected length of a resiliently flexible plastic profiled recloseable fastener strip from a reel containing a continuous length thereof transversely to an elongate length of web material for secure ent thereto, comprising the steps of: orienting during set up a cutter member of a cutting station a predetermined distance from a longitudinal center line of the 'web material and orienting an initial first length of the resilient flexible plastic profiled recloseable fastener strip intermittent the cutting station and the center line of the web material; and thereafter cyclically advancing a second length of the strip past the cutter station and cutting the strip during a time that the strip is not being advanced followed immediately by a further advancing of a length of the strip equal to the first length past the cutting station and activating a tack or seal of a strip to the web material whereby the initial first length and the second length have a combined length equal to the selected length.

2. The method according to Claim 1, wherein the initial first length is oriented to 50% of the selected length.

3. The method according to Claim 1, wherein the initial first length is oriented to 40% of the selected length.

4. The method according to Claim 1, wherein the first length and the second length are determined by controlling the time intervals of operation or number of turns of a feed motor feeding the strip immediately before the strip cutting step and immediately after the strip cutting step.