# US 5,350,928 A · Apparatus and method for detecting perforations

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- Number: US 5,350,928 A
- Document ID: US5350928A
- Status: Granted
- Kind: A
- Application number: 08/016,340
- Filed: 1993-02-11
- Granted: 1994-09-27
- Earliest claimed: 1993-02-11
- Assignees: FMC Corporation
- Inventors: Peter J. Hatchell; Danford C. Anderson; Ronald L. Lotto
- Web page: https://patentgrep.com/patent/US5350928A

## CPC

- B65H 43/00: Use of control, checking, or safety devices, e.g. automatic devices comprising an element for sensing a variable
- B65H 2511/16: Irregularities, e.g. protuberances
- B65H 2553/41: Photoelectric detectors
- Y10T 225/35: Work-parting pullers [bursters]
- B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An apparatus for use in a system for making bags or the like from a continuous web or sheet of film material, the system including a perforator for imparting series of transverse perforations onto the web at regularly spaced intervals, which comprises a spreader roll having a reduced diameter portion between two enlarged diameter portions; a switch device located adjacent the reduced diameter portion; wherein the large diameter portions cause each series of perforation to pull apart and form a gap as the web is drawn over the spreader roll; and wherein the switch device is capable of being activated each time a gap passes in close proximity to the switch device.

## Claims

### Claim 1

An apparatus for use in a system for making bags from a continuous web or sheet of film material, the system including means for imparting series of transverse perforations onto the web at regularly spaced intervals, which comprises:
a spreader roll having a reduced diameter portion between two enlarged diameter portions;
wherein the enlarged diameter portions cause a portion of each series Of perforations to pull apart and form a gap as the web is drawn over the spreader roll; and
switch means located adjacent the reduced diameter portion for detecting each gap.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the switch means is a photoswitch.

### Claim 3

A method of detecting series of perforations imparted onto a continuous web or sheet of film material at regularly spaced intervals which comprises:
spreading the web apart to form a small gap at each series of perforations; and
detecting each gap.

### Claim 4 (depends on 3)

The method of claim 3, further comprising the step of initially forming a slit in each series of perforations.