US3763823A - Glue applicator - Google Patents

Abstract

A glue applicator with a rotating roller having at least one indentation for receiving glue which is to be desposited on a cardboard blank when said blank passes by and contacts the roller. One or more channels in the roller for feeding liquid glue extend to the indentation and are in communication with a source of liquid glue. The roller is intended to be rotated continuously and the glue is fed to each indentation to fill it so that a slight bulb of glue will project beyond the circumferential surface of the roller when the area around the indentation is pressed against the blank.

Description

O United States atelit 1 [111 3,763,823

Nilsson Oct. 9, 1973 GLUE APPLICATOR Primary Examiner-Henry S. Jaudon 7 5] Inventor .glycldnegneniar Nilsson, Halmstad, Attorney sidney G. Faber et all [73] Assignee: Sprinter Pack AB, Halmstad, [57] ABSTRACT Sweden A glue applicator with a rotating roller having at least [22] Filed: Jan. 3, 1972 one indentation for receiving glue which is to be desposited on a cardboard blank when said blank passes (211 Appl' 2l504l by and contacts the roller. One or more channels in the roller for feeding liquid glue extend to the indenta- [52} US. Cl. 118/258, 118/261 tion and are in communication with a source of liquid [51] Int. Cl B44111 1/20 glue. The roller is intended to be rotated continuously [58] Field of Search 1 18/258, 259, 261, and the glue is fed to each indentation to fill it so that 1 18/262 a slight bulb of glue will project beyond the circumferential surface of the roller when the area around the [56] References Cited indentation is pressed against the blank.

UNITED STATES PATENTS 4 Claims, 2 Drawing Figures 2,464,040 3/1949 Huebner 118/258 2.597.893 5/1952 Nordquist 118/258 3.066.603

12/1962 Talarico 118/258 PATENTEU DC? 91913 1 GLUE APPLICATOR In the industrial application of glue on a large scale, the purely manual procedure using a brush, glue putty knife or the like has been replaced by different mechanical glue spreaders, usually in the form of rollers. As a rule, these devices operate in such a way that a rtating roller is partly positioned in a glue tray, thus coating its surface with glue. When an article is then pressed against this roller, a portion of the glue is transferred to the article. This transferred glue can be controlled by the viscosity of the glue, by grooves in the roller, by the selection of different roller material, etc. Moreover, in order to obtain a more even glue application, several rollers may be used so that the glue is transferred to the article by an intermediate roller.

The present invention relates to an improvement of such glue rollers. In accordance with the invention the glue is supplied through channels in the roller to its circumferential surface so as to provide a coating with varying glue patterns, coating on uneven cardboard surfaces and joints between two cardboard layers re spectively, etc.

The invention shall now be described in detail with reference to the accompanying drawing;

FIG. 1 is a cross section of the glue applicator according to the invention, and

FIG. 2 is a diagrammatic side viewof the glue applicator with a scraper during operation.

The glue roller according to the invention comprises an applicator roller 1 which is rotatably journalled on a cylindrical valve body 3 by means of ball bearings 2 and is driven via a sprocket, a pulley or the like 7 secured to the roller. The applicator roller 1 is formed by an inner spacer sleeve 4, a cylindrical casing and aroller sleeve 6. These members are sealed against each other with packings 8-11 and secured by nuts and locking screws l2-l4.

The glue applicator herein described is mainly intended for use with thermo-setting glue of the hotmelt type; however, the invention is not restricted to the use of this type of glue.

When used with thermo-setting glue, the entire glue applicator is kept heated by a centrally positionedheating element 24 so that the glue is prevented from hardening. The temperature is controlled by a thermostat via impulses sent from atemperature gauge 25.

When the applicator is used, the liquified glue is pumped from a glue source into the channel in the valve body 3 and is fed via aradial hole 16 into an inner slot I7 between the valve body 3 and the inner spacer sleeve 4. The glue then passes through a plurality ofholes 18 in the sleeve 4 to anouter slot 19 between the spacer sleeve 4 and thecylindrical casing 5. From theslot 19 the glue is fed through a plurality ofradial channels 20 in thecasing 5 and into aslot 21 between thecasing 5 and the detachably mountedroller sleeve 6.Grooves 23 with the pattern desired on the cardboard blanks to be glued are engraved, milled or the like in the outer surface of theshell 6. In FIG. 1 thegroove 23 is shown in cross-section but it is to be understood that the longitudinalext'ension ofgroove 23 on the dream-- ferential surface of the roller sleeve may have any desired configuration, length and direction. A number of such grooves may be provided and separated, and when desired the groove may have such small extension that it forms a spot. The application of glue often occurs only on some of the flaps on each cardboard blank before they are folded to form a box or the like. The corlays in production. Furthermore, with this technique,

the proper amount of glue may be applied in the form of a totally irregular pattern which may comprise lines of glue in the direction of movement of the cardboard and at desired angles relative thereto. Since the roller sleeve is easy to replace and because of the relatively low cost of making the various roller sleeves, the invention provides for the inexpensive, rapid and effective application of glue in all possible situations.

A large number ofsmaller holes 22 extend radially in thesleeve 6 from theslot 21 to thegrooves 23 and are spaced apart a distance from 2 to 4 mm. The diameter of the holes is somewhat less than the width of thegrooves 23.

The glue is pumped continuously out into thegroove 23. via theholes 22. Excess glue is scraped away by ascraper 26 and runs down into a collecting vessel from where it returns to the glue container. By holding the pressure and capacity of the glue pump constant, and by controlling the adjustment of the pump by means of a valve, therespective groove 23 will always be filled at the same rate. This rate is so selected that the glue is squeezed out due to its surface tension somewhat above the surface of theroller sleeve 6 and will thus lie as an elevation or bulb or ridge over the groove when that portion of the roller comes into contact with the cardboard blank. Should some fault cause an interruption of the supply of cardboard blanks to the glue applicator, this glue elevation will be scraped away by the scraper, each time the scraper passes by, without the surface of the roller sleeve or other component parts being smeared with glue. The glue applicator can thus operate regardless of a possible interruption of the cardboard blank supply without any particular measures being necessary, such as shutting off or cleaning the device. I

If the operation continues non stop i.e., without interruptions or other trouble the scraper has no function to fill. The amount of glue can then be regulated so that the quantity pumped out will correspond exactly to the quantity used during each complete revolution of the roller.

Since the glue in eachgroove 23 is elevated above the surrounding surface of the roller sleeve when contact is made with the surface of the cardboard blank,

uneven blanks can also be satisfactorily coated with depositing glue on a cardboard blank or the like when the blank passes by and engages the roller surface;

said roller having at least one internal slot for continholes in said outer sleeve communicating with said recess.

3. The glue applicator of claim 2, further comprising an inner spacer sleeve surrounding said shaft and forming a bearing shaft for the cylindrical casing, there being cylindrical glue distributing chambers located between said shaft, said spacer sleeve and said cylindrical casing, which chambers are interconnected via substantially radial channels in the spacer sleeve for supplying glue to the channels in the cylindrical casing.

4. The glue applicator of claim 3, comprising a scraper bearing against the surface of the roller outer sleeve and for scraping off excess glue which arises if the supply of cardboard blanks is interrupted momentarily, or if some other fault occurs.

Claims (4)

1. A glue applicator comprising: a shaft; a roller rotatably mounted on said shaft; said shaft having a conduit connectable at one end with a source of glue and having a glue feeding opening positioned within the interior of said roller; said roller having at least one glue receiving recess along the circumferential surface of the roller for depositing glue on a cardboard blank or the like when the blank passes by and engages the roller surface; said roller having at least one internal slot for continuously coupling the glue feeding opening to said recess to fill only said recess with glue whereby the surface of the glue in said recess extends beyond the circumferential surface of said roller.

2. The glue applicator of claim 1 wherein said roller comprises a cylindrical casing surrounding and rotatably journaled on said shaft; a detachably mounted outer cylindrical sleeve containing said recess and being mounted for rotation with said casing; a slot being provided between said casing and said outer sleeve which slot constitutes a distributing chamber for the glue supplied to the recess through holes in said outer sleeve communicating with said recess.

3. The glue applicator of claim 2, further comprising an inner spacer sleeve surrounding said shaft and forming a bearing shaft for the cylindrical casing, there being cylindrical glue distributing chambers located between said shaft, said spacer sleeve and said cylindrical casing, which chambers are interconnected via substantially radial channels in the spacer sleeve for supplying glue to the channels in the cylindrical casing.

4. The glue applicator of claim 3, comprising a scraper bearing against the surface of the roller outer sleeve and for scraping off excess glue which arises if the supply of cardboard blanks is interrupted momentarily, or if some other fault occurs.

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