US 5,776,285 AGranted

Method and apparatus for applying adhesive to a closure flap of envelopes

AssigneeWinkler & Duennebier Maschinenfabrik und Eisengiesserei KG

InventorMartin Blumle

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Abstract

Adhesive, preferably pressure sensitive adhesive, is applied to an article f manufacture, such as the closure flap of an envelope or paper bag in such a way that the adhesive is protected against activation prior to closing the article. For this purpose, the adhesive is first applied to a continuous web or tape of a carrier material that either has an inherent anti-stick characteristic or is provided with an anti-stick surface coating relative to the adhesive to be applied. Preferably, the adhesive does not cover the entire surface of the carrier strip, but rather covers only areas in the form of stripes extending at least partly across the width of the carrier web. The adhesive stripes are spaced from one another and preferably also from at least one edge of the carrier web or tape. The carrier web is then severed into strips, each provided with one adhesive stripe and these strips with the adhesive stripes thereon are then secured between two rollers to the surface area to be provided with the adhesive. The web material forms a substrate or backing for each individual adhesive stripe. The backing is then removed when the article is to be closed. The apparatus for this purpose is provided with a feed advance for the tape or web, with an adhesive applicator and with a cutter that preferably also functions as a strip applicator.

Claims16

Dependent claims

A method for applying adhesive to a closure flap of envelopes comprising the following steps:

(a) feeding said envelopes on a conveyor (33) including a counter roller (24) in a feed advance direction (2B), whereby closure flaps of said envelopes are oriented substantially horizontally and crosswise to said feed advance direction;
(b) feeding a continuous flat, unfolded carrier web (15) having an anti-stick surface, through an adhesive applicator device (1, 1A);
(c) sequentially applying adhesive stripes (3C) to said anti-stick surface of said flat, unfolded carrier web (15) so that said adhesive stripes (3C) extend perpendicularly to and crosswise to a length of said web (15) on said anti-stick surface and so that a spacing (S) without adhesive is provided between each two neighboring adhesive stripes (3C) on said flat, unfolded carrier web (15);
(d) using a single cutter roller (21) also as a transfer roller for cooperation with said counter roller (24) in a transfer plane common to both rollers (21, 24);
(e) cutting said flat, unfolded carrier web (15) along and within said spacing (S) without adhesive with said single cutting roller (21) into individual adhesive carrying cover strips (3A), each strip having a carrier web backing and one of said adhesive stripes (3C) on said anti-stick surface;
and
(f) transferring and securing said cover strips (3A) with said single cutting roller (21) now operating as a transfer roller to said envelopes at said counter roller (24) so that a strip securing roller pressure is effective perpendicularly to a length of said cover strips (3A) and simultaneously along a length of said cover strips whereby one of said adhesive stripes (3C) is sandwiched between said backing formed by said flat, unfolded carrier web (15) and a surface of each closure flap, and so that said flat, unfolded carrier web (15) and said envelopes (2) can travel in vertical alignment with each other toward said transfer plane common to both rollers (21, 24).

4 more elements

An apparatus for applying an adhesive to envelope closure flaps, comprising an adhesive applicator mechanism (1) including a supply device (14, 20) for supplying a flat, unfolded carrier web (15) having an anti-stick surface, rotatable adhesive applicator roller (6) and feed advance and guide rollers (8 to 13) for transporting said flat, unfolded carrier web (15) through said adhesive applicator mechanism (1) for applying adhesive stripes (3C) to said anti-stick surface of said flat, unfolded adhesive carrier web (15) by said adhesive applicator mechanism (1) so that said adhesive stripes (3C) extend on said anti-stick surface perpendicularly to a length of said carrier web (15) and crosswise to said anti-stick surface so that a spacing (S) without adhesive is provided between each two neighboring adhesive stripes (3C), a web cutting and strip applicator (16) arranged downstream of said adhesive applicator mechanism as viewed in a feed advance direction of said carrier web (15), said web cutting and strip applicator (16) comprising a combined web cutter and strip transfer roller (21) including a cutting knife (22) carried by said web cutter and strip transfer roller (21) and a counter member (23) positioned for cooperation with said cutting knife (22) on said roller (21) along said spacing (S) without adhesive thereby cutting said flat, unfolded carrier web (15) along and within each said spacing (S) without adhesive into cut strips (3A), each cut strip (3A) having one of said adhesive stripes (3C) at least on part of one surface of a strip (3A) forming a backing for said adhesive stripe (3C), said feed advance and guide rollers comprising a pair of feed and guide rollers (8) arranged opposite each other and directly upstream of said web cutter and strip transfer roller (21) for feeding said flat, unfolded carrier web onto said web cutter and strip transfer roller (21), said apparatus further comprising a roller conveyor (33) for transporting envelopes in a feed advance direction (2B, 33B), said roller conveyor (33) including a counter roller (24) positioned for cooperation with said web cutter and strip transfer roller (21) in a transfer plane common to both rollers (21, 24) for applying cut strips (3A) to said envelope closure flaps, said conveyor (33) comprising a first group of feed advance rollers (26) arranged upstream of said counter roller (24) and a second group of feed advance rollers (25) arranged downstream of said counter roller (24), said conveyor (33) and said feed advance and guide rollers (8 to 13) being arranged in vertical alignment with each other so that said envelopes (2) and said cut strips (3A) can travel into alignment with each other in said common transfer plane, whereby a transfer pressure applied by said rollers (21, 24) to said cut strips (3A) is effective perpendicularly to a length of said cut strips (3A) and simultaneously along said cut strips (3A), and wherein said feed advance and guide rollers comprise a guide and counter roller (10) for said adhesive applicator roller (6), a mounting bracket (17) journalled to said adhesive applicator mechanism (1) for a tilting movement of said mounting bracket, said guide and counter roller (10) being rotatably mounted to said mounting bracket (17), and a drive (18) connected to said mounting bracket (17) for pressing said guide and counter roller (10) against said adhesive applicator roller (6).

An apparatus for applying an adhesive to envelope closure flaps, comprising a supply device (14A, 20A) for supplying a flat, unfolded carrier web (15A) having an anti-stick surface, an adhesive applicator mechanism (1A) including feed advance and guide rollers (8A, 10A, 10B, 13A) for applying adhesive stripes (3C) to said anti-stick surface of said flat, unfolded adhesive carrier web (15A) by said adhesive applicator mechanism (1A) so that said adhesive stripes (3C) extend on said anti-stick surface perpendicularly to a length of said carrier web (15) and crosswise to said anti-stick surface with a spacing (S) without adhesive between each two neighboring adhesive stripes (3C), a web cutting and applicator mechanism (16A) arranged downstream of said adhesive applicator mechanism (1A) as viewed in a feed advance direction of said carrier web (15A), said web cutting and applicator mechanism (16A) comprising a combined web cutter and strip transfer roller (21A) including a cutting knife (22A) carried by said web cutter and strip transfer roller (21A) and a counter member (23A) positioned for cooperation with said cutting knife (22A) on said roller (21A) along said spacing (S) without adhesive thereby cutting said flat, unfolded carrier web (15A) along and within each said spacing (S) without adhesive into cut strips (3A), each cut strip carrying one of said adhesive stripes (3C) at least on part of one surface of said cut strip forming a backing for said adhesive stripes (3C), said feed advance and guide rollers comprising a pair of feed and guide rollers (8A) arranged opposite each other and upstream of said web cutter and strip transfer roller (21A) for feeding said flat, unfolded carrier web (15A) onto said web cutter and strip transfer roller (21A), said apparatus further comprising a roller conveyor (33) for transporting envelopes in a feed advance direction (2B, 33B), said roller conveyor (33) including a counter roller (24A) positioned for cooperation with said web cutter and strip transfer roller (21A) in a transfer plane common to both rollers (21A, 24A) for applying cut strips (3A) to said envelope closure flaps, said roller conveyor (33) comprising a first group of feed advance rollers (26A) arranged upstream of said counter roller (24A) and a second group of feed advance rollers (25A) arranged downstream of said counter roller (24A), said roller conveyor (33) and said feed advance and guide rollers being arranged in vertical alignment with each other so that said envelopes (2) and said strips (3A) can travel into alignment with each other in said common transfer plane, wherein a transfer pressure applied by said rollers (21A, 24A) to said cut strips (3A) is effective perpendicularly to a length of said cut strips (3A) and simultaneously along said cut strips (3A), wherein said adhesive applicator mechanism (1A) comprises an adhesive spray nozzle (40, 40A) and a counter roller (41A) arranged opposite said adhesive spray nozzle (40, 40A) for presenting said carrier web (15A) to said adhesive spray nozzle for applying said adhesive stripes (3C) to said anti-stick surface of said carrier web (15A), said adhesive spray nozzle (40, 40A) having a slot with a slot length corresponding to a length of said adhesive stripes (3C), said nozzle slot length extending perpendicularly and crosswise to a length of said adhesive carrier web (15A) and parallel to said anti-stick surface of said adhesive carrier, web (15A) for applying said stripes (3C) to said carrier web (15A) with said spacings (S) without adhesive between each two neighboring adhesive stripes (3C).

Dependencies are inferred from the claim text.