Product-out-of-registration control for high speed wrapping machine

• US 4,722,168 A
• Filed: 06/25/1987
• Issued: 02/02/1988
• Est. Priority Date: 06/25/1987
• Status: Expired due to Term

• Current Assignee: SIG Pack Incorporated
• Original Assignee: Doboy Packaging Machinery, Inc.
• Inventors: Heaney, Steven R.
• Primary Examiner(s): Culver, Horace M.
• Application Number:
  US07/066,255
• Time in Patent Office: 222 Days
• Field of Search: 53/450, 53/51, 53/373, 53/55, 53/501, 53/75, 53/76, 53/77, 53/550
• US Class Current: 53/450
• CPC Class Codes: B65B 57/14 and operating to control, or stop, the feed of articles or material to be packaged
• CPC Class Codes: B65B 9/067 the web advancing continuously B65B9/08 takes precedence

Abstract

A method and apparatus for increasing the performance and through-put of a high speed horizontal wrapping machine of the type having mechanically independently driven infeed, film drive and cut/seal head motors, each controlled by a shared programmed microprocessor whereby in the event that a product to be wrapped gets out of registration to the point where the machine'"'"'s cut/seal head blades might otherwise engage the product being wrapped rather than only the film between two adjacent products, the condition is sensed and a software routine is called which causes the cut/seal heads to come to a stop in the open condition while the film tube continues to be fed until all the products, including the one out of registration and all those downstream from it, exit the wrapper, at which point the wrapper resumes its normal running mode. In this fashion, damage to the cut/seal head and associated down-time to clear the jam is avoided.

Claims

1. A software method of operating a microprocessor controlled packaging machine of the type comprising means for drawing a web of film having registration marks printed thereon from a supply reel over forming means to create a film tube while simultaneously feeding products to be wrapped through said forming means to be carried by said film tube to a cut/seal station where blade and anvil means are intended to come together in an inter-product space to transversely cut and seal the film to create individual packages whereby said cut/seal heads, the product feeding means and said means for drawing said film are operated so as to prevent said blade and anvil means from contacting said products should said products lose spacial registration in the course of travel through said packaging machine comprising the steps of:

(a) sensing for the presence of a product at a predetermined location upstream of said cut/seal station at a time synchronized with the position of said blade and anvil;

(b) stopping the product feeding means, said film drawing means and said blade and anvil, leaving said blade and anvil open with respect to one another;

(c) computing the number of products in said film tube between said forming means and said cut/seal station;

(d) re-starting only said film drawing means and running same until the number of products computed in step (c) have passed between the opened blade and anvil;

(e) re-stopping said film drawing means when said film registration marks reach a predetermined position relative to said product feeding means following the occurrence of step (d); and

(f) initiating the normal running mode of said microprocessor controlled wrapping machine.

2. The method as in claim 1 and further including the steps of:

(g) testing the position of said registration marks on said film; and

(h) aborting steps (b) through (f) if the test of step (g) shows that said registration marks on said film has occurred out of normal position.

3. A method of wrapping products in packages formed from a continuous film of packaging material, with each package containing a cut length of film, comprising the steps of:

(a) shaping a continuous film of packaging material into a continuous tube by drawing the film past a former;

(b) drawing the continuous film of packaging material beyond the former and through a cutting and sealing station;

(c) feeding products to be packaged into the former and the continuous tube of packaging material at a predetermined rate;

(d) cutting and sealing the continuous tube of packaging material as each product moves past the cutting and sealing station;

(e) determining the relative orientation between each product and its associated cut length of film moving past the former;

(f) sensing for the presence of a product at a predetermined location upstream of said cutting and sealing station at a time synchronized with the position of the cutting and sealing means at said cutting and sealing station;

(g) stopping the product feeding means, the film drawing means and the cutting and sealing means leaving said cutting and sealing means apart relative to one another when step (f) finds a product at said location;

(h) determining the number of individual products contained in said film tube between said former and said cutting and sealing station when the result of step (f) finds a product at said location;

(i) re-starting only said film drawing means for a time interval sufficient to allow the computed number of products to pass through said cutting and sealing station;

(j) re-stopping said film drawing means when said film registration marks reach a predetermined position relative to said product feeding means; and

(k) initiating the normal running mode of said microprocessor controlled wrapping machine.

4. A horizontal wrapping machine for wrapping products in packages formed from a continuous film of packaging material wherein each package contains a cut length of film, comprising:

(a) a former for shaping a continuous film of packaging material drawn past the former into a continuous tube;

(b) film drive means for drawing the continuous film of packaging material past the former and past a cutting and sealing station;

(c) product infeed means for feeding products to be packaged into said former and said continuous tube of packaging material;

(d) rotary cutting and sealing means disposed downstream of said former and including cooperating blade and anvil means for creating a transverse seal and cutting said continuous tube into discrete cut lengths, each containing a product;

(e) microprocessor-based controller means coupled to said film drive means, said product infeed means and said rotary cutting and sealing means;

(f) means for sensing the presence and absence of a product at a predetermined location upstream from said cutting and sealing means at a time synchronized with the movement of said blade and said anvil and providing a flag signal to said microprocessor-based controller means where unaltered operation of said film drive means and said cutting and sealing means would result in said blade and anvil contacting a product;

(g) said microprocessor-based controller means stopping said product infeed means, said film drive means and said means for cutting and sealing, leaving said blade and anvil open with respect to one another, and having means for computing the number of products in said film tube between said former and said cutting and sealing means;

(h) means responsive to the results of the computation for re-starting only said film drive means sufficiently long to have the computed number of products exit between said opened blade and anvil; and

(i) means in said microprocessor-based controller means for re-initiating the normal running mode of said horizontal wrapping machine following the exit of the computed number of products between the opened blade and anvil.