Zipper registration using eye-mark encoder

Abstract

The apparatus uses a servo motor and an accumulator dancer arm to buffer the motion of film, with zipper and clips or sliders already inserted, in a zipper-sealing machine. The servo drives the film to an eye-mark and then stops the film. Upstream of the servo motor, the film and zipper stop so that the zipper can be processed, such as by ultrasonic crush stations and clip insertion stations. Downstream of the servo motor, the film runs out of an accumulator to the bagger/wrapper apparatus.

Description

This application claims priority under 35 U.S.C. §119(e) of provisional application Ser. No. 61/044,563 filed on Apr. 14, 2008, entitled “Zipper Registration Using Eye-Mark Encoder”.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the manufacture of reclosable packaging and pertains to a method for improving registration when inserting a zipper with slider clips into packaging film, by use of an eye-mark and an encoder.

2. Description of the Prior Art

The prior art of zipper registration in the manufacture of reclosable packages and bags is well-developed for its intended purposes. For example, commonly-assigned U.S. Pat. No. 7,172,545 entitled “Registration of Intermittently Moved Fastener Tape With Continuously Moving Web” issued on Feb. 6, 2007 to Howell and Wallace discloses an apparatus and method using continuous film motion through the zipper-sealing machine and only the zipper has intermittent motion (stop-starts) with the aid of an accumulation assembly. Related art is disclosed in US 2006/0207727 entitled “Apparatus for Repeatedly Advancing Fastener Tape a Predetermined Distance” filed on Mar. 16, 2005 by Cortigiano and US 2008/0134632 entitled “Method of Registering Zipper for Reclosable Package”, filed on Dec. 6, 2006 by Howell.

Other prior art devices utilize a similar method to accumulate film. The machine jogs the film and attached zipper using a servo to eye-mark and stop it. Upstream of the stop, an ultrasonic unit stomps the zipper but no clip is inserted. Downstream of the stop, the film with the zipper attached is fed out of an accumulator to the bagger.

However, further improvements are sought in the registration of the zipper, particularly when inserting zipper with clips into packaging film.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide improvements in the registration of a zipper in the manufacture of reclosable packages, particularly when inserting zipper with clips into packaging film.

It is therefore a further object of the present invention to allow a continuous motion bagger/wrapper to be coupled with an intermittent motion zipper-sealing machine.

These and other objects are attained by a method and apparatus which uses a servo motor and an accumulator dancer arm to buffer a stop-start motion of film, with the zipper and clips (or sliders) already attached, in the zipper-sealing machine. The servo drives the film to an eye-mark and then stops the film. Downstream of the servo motor, film,runs out of an accumulator to the vertical or horizontal bagger. Upstream of the servo motor, the film and zipper stops so that the zipper can be processed, typically by an ultrasonic crush application and a clip application.

DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become apparent from the following description and from the accompanying drawings, wherein:

FIG. 1 is a schematic of the zipper sealing portion of the apparatus of the present invention.

FIG. 2 is a schematic of the zipper insertion portion of the apparatus of the present invention.

FIG. 3 is a schematic of the eye-mark sensor and accumulator portion of the apparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings wherein like numerals refer to like elements throughout the several views, one sees from FIG. 1 that the apparatus 10 includes spool 12 which serves as a source of zipper 100. Zipper 100 passes over a first accumulator (or unwind dancer) 14 which includes idler wheels 16, 18 with fixed axes of rotation and unwind dancer arm 20 which moves vertically (in the illustrated orientation) to accommodate differences in speed between the zipper 100 being fed from spool 12 and the zipper I 00 being fed through the downstream stations—first ultrasonic crush station 22, second ultrasonic crush station 24, first clip insertion station 26 and second clip insertion station 28. First and second ultrasonic crush stations 22, 24 apply ultrasonic energy to create the ends of the zipper segments, while first and second clip insertion stations 26, 28 insert the clips (alternately referred to as sliders) which allow the consumer or user to open and close the resulting zipper segments by separating and interlocking, respectively, the zipper profiles.

As shown in FIG. 2, zipper 100 is then captured by zipper insertion arm 30 and sealed to polymeric web or film 200. Film 200 includes periodic eye-marks 202, such as, but not limited to, small rectangular ink marks positioned toward the outer edge of film 200. The eye-marks 202 are positioned a specific distance apart (such as, but not limited to, a package width).

As shown in FIG. 3, film 200 (with zipper 100 attached) is scanned by eye-mark sensor 34 and driven by servo motor 36 (and associated drive mechanism 38). Film 200 is then fed through second accumulator 40 which includes idler wheels 42, 44 with fixed axes of rotation and an accumulator dancer arm 46 which moves vertically (in the illustrated orientation) to accommodate differences in speed between the film 200 being fed from the zipper insertion arm 30 and being fed to the bagger/wrapper apparatus (not shown), particularly to provide a substantially constant speed of feeding to the bagger/wrapper apparatus (not shown).

As film 200 passes in front of eye-mark sensor 34 and an eye-mark 202 is detected, the eye-mark sensor 34 signals servo motor 36 to momentarily stop film 200 upstream of servo motor 36. Zipper 100 is likewise stopped upstream as it passes through first and second ultrasonic crush stations 22, 24 and first and second clip insertion stations 26, 28 thereby permitting the crush and clip insertion operations to be performed on a momentarily stationary zipper. Meanwhile, the operation of the second accumulator 40 allows the film 200 (with zipper 100 attached) to continuously feed the bagger/wrapper apparatus at a substantially constant speed. After the operations on stationary zipper 100 at stations 22, 24, 26, 28 are completed, the servo motor 36 drives zipper 100 and film 200 at a rate fast enough to replenish the second accumulator 40. The process then repeats itself, thereby allowing for intermittent motion of the zipper 100 and film 200 while providing a continuous feed at a substantially constant speed from second accumulator 40 to the bagger/wrapper apparatus.

Thus the several aforementioned objects and advantages are most effectively attained. Although preferred embodiments of the invention have been disclosed and described in detail herein, it should be understood that this invention is in no sense limited thereby and its scope is to be determined by that of the appended claims.

Claims

1. A process of manufacturing at least a portion of a reclosable package including the steps of:

providing a length of zipper material;

providing a station for inserting clips onto the length of zipper material;

providing a length of film;

sealing the length of zipper material to the length of film;

scanning the film for an eye-mark; and

upon detecting the eye-mark, momentarily stopping the length of zipper material and the length of film and activating the station for inserting clips onto the length of zipper material.

2. The process of claim 1 wherein motion of the film and the zipper is momentarily resumed after clips have been inserted on the length of zipper material.

3. The process of claim 2 wherein the step of providing a length of zipper material is performed by a spool.

4. The process of claim 3 further including the step of providing a first accumulator downstream of the spool whereby the spool can continue to provide the length of zipper material during the step of momentarily stopping the length of zipper material.

5. The process of claim 4 further including the step of providing a crush station for performing periodic crush operations on the length of zipper.

6. The process of claim 5 wherein the periodic crush operations are performed during the momentary stopping of the length of zipper material.

7. The process of claim 6 further including the step of driving the film with a servo motor.

8. The process of claim 7 wherein the step of driving the film with a servo motor and the step of momentarily stopping the zipper are responsive to the step of scanning the film for eye-mark.

9. The process of claim 8 further including the step of providing a second accumulator downstream of the servo motor.

10. The process of claim 9 wherein speed of the film and zipper from the second accumulator remains substantially constant.

11. An apparatus for manufacturing at least a portion of a reclosable package including:

a source of a length of zipper material;

a station for inserting clips onto the length of zipper material;

a source of a length of film;

a sealer for sealing the length of zipper material to the length of film;

a scanner for scanning the film for an eye-mark; and

wherein upon the scanner detecting the eye-mark, the length of zipper material and the length of film are momentarily stopped and station inserts clips onto the length of zipper material.

12. The apparatus of claim 11 wherein motion of the film and the zipper is momentarily resumed after clips have been inserted on the length of zipper material.

13. The apparatus of claim 12 wherein the source of a length of zipper material is a spool.

14. The apparatus of claim 13 further including a first accumulator downstream of the spool whereby the spool can continue to provide the length of zipper material while the length of zipper material is momentarily stopped.

15. The apparatus of claim 14 further including a crush station for performing periodic crush operations on the length of zipper.

16. The apparatus of claim 15 wherein the periodic crush operations are performed while the length of zipper material is momentarily stopped.

17. The apparatus of claim 16 further including a servo motor to drive the film.

18. The apparatus of claim 17 wherein the servo motor is responsive to the scanner.

19. The apparatus of claim 18 further including a second accumulator downstream of the servo motor.

20. The apparatus of claim 19 wherein speed of the film and zipper from the second accumulator remains substantially constant.