GB2029280A - Glue dispensing apparatus for a labelling machine. - Google Patents

Abstract

The apparatus comprises a pressurised glue reservoir (20) for supplying glue to be dispensed to an applicator (10) the supply of glue being controlled by an air operated valve (22). The air operated valve (22) is operated by means of compressed air, the supply of which is controlled by a solenoid operated valve (24) controlled by means of a microswitch (25) which is operable whenever a label for which glue is to be dispensed operates the actuating arm (26) of the microswitch (25). The applicator (10) [Fig. 1] is a hollow cylindrical tube having a plurality of axially spaced apart circumferential grooves (13) in the base of each of which an aperture (15) is provided communicating with the central bore (11) of the tube, so that glue supplied into the hollow tube can exude through the apertures (15) into the grooves (13) so that a label brushing past the applicator (10) will have a quantity of glue deposited thereon. <IMAGE>

Description

SPECIFICATION Fluid application apparatus The present invention relates to an improved fluid application system, more particularly an arrangement for dispensing glue for use on labelling machines.

In the packaging industry labels must often be attached to glass, plastics material, metal or cardboard containers and this may be done by one of several methods involving hot or cold glueing.

In one example, for attaching labels to plastics material bottles, a bottle to be labelled approaches a labelling station where the front-end of a label is attached to the bottle by hot glueing. The bottle is then caused to perform one full revolution as it passes through the labelling station thereby drawing the label from a stack of labels in a magazine. The length of the label is such that it will wrap around the bottle with a sufficient overlap to allow glueing of the tail end of the label to the front end of the label at this overlap.

Therefore, as the label is drawn from the magazine the rear surface of the tail end of the label is caused to brush against a glue applicator, which deposits glue on the rear surface of the label, which is then pressed into contact with the front end of the label in the region of their overlap. The labelled bottle then proceeds to the next station.

The cold glue applicator for the tail end of the label in the known arrangement utilises a continuous wire loop mounted on two pulleys mounted vertically above one another with the lower pulley dipping into a glue reservoir.

The wire may be continuously or intermittently driven so that it dips into the reservoir and carries glue up to a position where the tail end of the label brushes against the vertical section of the wire emerging from the glue reservoir thereby applying glue to the label. The wire loop is normally in the form of a "curtain wire", i.e. a tightly coiled wire.

Whilst this glue applicator can usually provide a satisfactory supply of glue to be applied to the tail end of the label the arrangement needs constant checking to ensure that the tensioning of the wire is correct so that an adequate and uniform application of glue is achieved.

It is the aim of the present invention to provide a modified form of glue applicator particularly suitable for use in a cold glueing assembly on a labelling machine which provides a uniform application of the appropriate quantity of glue when required and involves the minimum amount of checking and maintenance.

According to the present invention there is provided a fluid application apparatus comprising a hollow cylindrical fluid applicator, a pressurized fluid reservoir connected to said fluid applicator via a valve, said valve being opened or closed in accordance with a signal provided by a control system so as to enable a predetermined quantity of fluid to be transmitted from the reservoir to the applicator.

Preferably the control system utilises compressed air to open or close the valve and to pressurize the reservoir. The signal provided to the valve may be provided by a solenoid operated control valve actuatable by means of a microswitch.

Further preferabiy, the fluid applicator comprises a hollow cylindrical tube closed at one end, having a plurality of axially spaced apart circumferential grooves, with at least one aperture, communicating with the central bore of the tube, being provided 'r +he base of each groove.

Whilst the applicator and the application apparatus of the present invention can be used for applying any fluid to a passing article, it is principally intended for use in a labelling machine for applying cold glue to the tail end of a label.

The present invention will be described further with reference to the accompanying drawings in which: Fig. 1 is a side view of an applicator, partly in section; Fig. 1 a is a front view of an elbow for the applicator of Fig. 1; and Fig. 2 is a schematic diagram of a fluid application apparatus.

A fluid applicator 10 is shown in Fig. 1 and comprises a hollow cylindrical tube having a central bore 111 which is closed at its lower end for example by a grub screw 12. A plurality of circumferential grooves 13 are provided on the outside surface of the tube axially spaced apart by portions 14. In the bottom of each of these grooves an aperture 1 5-is provided which communicates with the central bore 11 to permit the fluid, e.g. glue, to exude through the apertures into the grooves so that it may be deposited on an article coming into contact with the applicator 10.

The glue to be supplied to the applicator 10 is brought via an elbow 16 which is threaded onto the upper end of the applicator 10 and onco correctly positioned with respect to a label magazine, with which the applicator louis to be used, a locating lug 1 7 prevents the applicator tube 10 from rotating in use. The apertures 1 5 are set in an appropriate position so that they are in the most likely contact position for the label to be glued to ensure effective application of the glue.

Of course, several apertures 15 could, if desired, be provided in each groove 13.

A suitable arrangement of a pressurized glue supply system is shown in Fig. 2 in which a pressurized glue container 20 is connected via a valve 22, suitably air operated, to the glue applicator 10. The pressure in the glue container 20 is provided by compressed air supplied at inlet 1 9 which is regulated by means of air regulator 21. The air operated valve 22 is controlled by means of a solenoid operated 5-port air valve 24 which also receives its air supply from air regulator 21, via an air filter regblator unit 23. The-operation of the solenoid operated air valve 24 is controlled by a micro-switch 25 which is activated by bottles or other articles to be labelled passing into the labelling station and detected by the operating arm 26.The sequence of operations is as follows; After hot glueing of the front end of a label to a bottle the operating arm 26 of the micro-switch 25 is contacted by the bottle, which activates the solenoid which causes the valve 24 to open the glue valve 22 for a period of time determined by the length of time the micro-switch 25 is operated. Thus, glue is all lazed to pass from the pressurized container 20 to the glue applicator 10, so that when the bottle reaches a position adjacent the end of the magazine, glue is available on the glue applicator as the tail end of the label is drawn from the magazine. The tail end of the label contacts the glue applicator 10 and the newly glued portion of the label is then brought into contact with the leading edge of the label where they overlap, which then glues these ends together.

The length of time for which the valve 22 is open and the pressure maintained in the glue reservoir 20 determines the amount of glue made available at the glue applicator 10. This can be varied as required by altering the pressure in the glue reservoir 20 and/or by adjusting the length of the operating lever 26 of the micro-switch 25 so that it is contacted by the bottle for a shorter or longer period to enable less or more glue to pass to the glue applicator 10. The glue applicator 10 may be the same as that described above with reference to Fig. 1, although other types of glue applicator could be utilised with this system.

The pressurized glue supply system and the glue applicator described above provides an efficient and reliable means for applying glue to the tail end of a label in a labelling machine with the minimum of maintenance being required.

Although the present invention has been described with regard to a cold glueing assembly, it is quite possible that the same apparatus with minor modifications, could be utilised for a hot glueing assembly and further the system could be used for applying other fluids than glue to a surface either continuously or intermittently as required.

Claims (7)

1. A fluid application apparatus comprising a hollow cylindrical fluid applicator, a pressurized fluid reservoir connected to said applicator via a valve, said valve being opened or closed in accordance with a signal provided by a control system so as to enable a predetermined quantity of fluid to be transmitted from the reservoir to the applicator.

2. Apparatus as claimed in claim 1 in which the fluid applicator comprises a hollow cylindrical tube closed at one end and having a plurality of axially spaced apart circumferential grooves, with at least one aperture, communicating with the central bore of the tube, being provided in the base of each groove.

3. Apparatus as claimed in claim 1 or 2 wherein said valve between the fluid reservoir and the fluid applicator is operated by compressed air.

4. Apparatus as claimed in claim 3 wherein the supply of compressed air for opening said valve when fluid is to be dispensed, is controlled by means of a solenoid operated valve actuated by means of a microswitch operable whenever fluid is to be dispensed.

5. Apparatus as claimed in claim 4, wherein said microswitch is actuated by means of a lever arm arranged to be displaced by an article for which fluid is to be dispensed.

6. Apparatus as claimed in any preceding claim, in combination with a labelling apparatus wherein said fluid to be dispensed is glue.

7. A fluid application apparatus substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.