# US 10,870,507 B2 · Device for continuous compensation of stretching of film during drawing applicable on packaging machines > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,870,507 B2 - Document ID: US10870507B2 - Status: Granted - Kind: B2 - Application number: 15/555,461 - Filed: 2016-02-16 - Published: 2018-02-08 - Granted: 2020-12-22 - Earliest claimed: 2015-03-03 - Assignees: Pfm Iberica Packaging Machinery, S.A. - Applicants: Pfm Iberica Packaging Machinery S.A. - Inventors: Andrea Fioravanti - Web page: https://patentgrep.com/patent/US10870507B2 ## CPC - B65B 9/073: the web having intermittent motion (B65B9/08 takes precedence) - B65B 9/093: the web having intermittent motion - B65B 9/2014: {Tube advancing means} - B65B 9/2028: {Rollers or belts} - B65B 9/2035: {Tube guiding means} - B65B 41/16: by rollers - B65B 41/18: Registering sheets, blanks, or webs - B65H 23/1882: {and controlling longitudinal register of web} - B65H 2301/4491: transforming movement from continuous to intermittent or vice versa - B65B: MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING (bundling and pressing devices for cigars A24C1/44; devices for tensioning and securing binders adapted to be supported by the article or articles to be bound B25B25/00; applying closure members to bottles, jars or similar containers B67B1/00-B67B6/00; concurrent cleaning, filling and closing of bottles B67C7/00; emptying bottles, jars, cans, casks, barrels or similar containers B67C9/00) - B65H: HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES ## Abstract Described is a compensating device applicable on intermittent advancement packaging machines with wrapping material constituted by a film made of a flexible plastic material, for continuous compensating of a stretching of the film during drawing thereof, the machine comprising a first drawing group of the film, a mobile element able to exert a determined force on the film during advancement, the mobile element being conventionally known as a dancer and a second drawing group of the film arranged downstream of the first drawing group, where each drawing group is provided with a sensor for detecting markers located at regular intervals along the film, the compensating device being constituted by a third drawing group, located between the first and second drawing groups, the third drawing group being provided with a marker sensor, the third drawing group being provided with independent motorisation and an automatic roller opening system. ## Claims ### Claim 1 A compensating device applicable on intermittent advancement packaging machines with wrapping material constituted by a film made of a flexible plastic material, for continuous compensating of a stretching of the film during drawing thereof, the machine comprising: a sealing station; a cutting station; a first drawing group of the film, a mobile element able to exert a determined force on the film during advancement, the mobile element comprising a dancer; a second drawing group of the film arranged downstream of the first drawing group and disposed between the sealing station and the cutting station, wherein each of the first and second drawing groups is provided with a marker sensor for detecting markers located at regular intervals along the film; and a third drawing group, located between the first and second drawing groups and upstream of the sealing station and downstream of the mobile element, the third drawing group being provided with a marker sensor, the third drawing group being provided with independent motorization and an automatic roller opening mechanism, wherein the roller opening mechanism works in a synchronized way with the first drawing group and the second drawing group and contemporaneously compares a signal of a marker sensor of the third drawing group with a marker sensor of the second drawing group during drawing the film. ### Claim 2 (depends on 1) The device according to claim 1, wherein: in a case in which an overstretching of the film has been verified, the motorisation of the third drawing group accelerates or decelerates by an amount equal to the difference, thus compensating for the stretching. ### Claim 3 (depends on 1) The device according to claim 1, wherein the third drawing group is controlled and managed by a personal computer (PC) which also manages the first drawing group and the second drawing group. ### Claim 4 (depends on 3) The device according to claim 3, wherein the PC is able to: calculate times and distances between the markers, as it receives the signal from the marker sensors; compare the received signals, and consequently direct the motors of the third drawing group to accelerate or decelerate rollers of the third drawing group, or near or distance the rollers from one another. ### Claim 5 A film stretching compensation device for a packaging machine with intermittent advancement movement, a wrapping material being constituted by a film made of a flexible plastic material, for carrying out a continuous compensation of film stretching during drawing thereof, the machine comprising: a sealing station; a cutting station; a first film drawing unit including motorized first driving rollers; a further mobile roller element exerting a given force on the film during advancement thereof; a second film drawing unit including motorized second driving rollers arranged downstream of the first film drawing unit group and disposed between the sealing station and the cutting station, where each film drawing unit comprises a second marker sensor for detecting markers located at regular intervals along the film; wherein said film stretching compensation device comprises a third film drawing unit and upstream of the sealing station and downstream of the mobile element, located between the first and second film drawing units, the third film drawing unit comprising a third marker sensor, as well as a motor and a roller opening mechanism for automatically controlling a displacement of driving rollers of the third film drawing unit, wherein the roller opening mechanism works in a synchronized way with the first drawing group and the second drawing group and contemporaneously compares a signal of the third marker sensor of the third drawing group with the second marker sensor of the second drawing group during drawing the film. ### Claim 6 (depends on 5) The device of claim 5, wherein the third drawing unit comprises a controlled roller opening mechanism which, during a film drawing operation, works in a synchronised way with the first and second drawing units and simultaneously compares a signal of the marker sensor thereof with the marker sensor of a subsequent drawing unit. ### Claim 7 (depends on 5) The device of claim 5, wherein the third drawing unit is controlled and managed by a personal computer (PC) which also manages the first drawing unit and the second drawing unit. ### Claim 8 (depends on 7) The device of claim 7, wherein the PC is configured to: calculate times and distances between the markers, as it receives the signal from the marker sensors; compare the received signals; and consequently direct motors of the third drawing unit to either accelerate or decelerate the rollers, or move the rollers close or away from each other.