US3427932A

US3427932A - Apparatus for attaching container covers by adhesive means

Info

Publication number: US3427932A
Application number: US568492A
Authority: US
Inventors: Edward E Wagner
Original assignee: Philip Morris USA Inc
Current assignee: Philip Morris USA Inc
Priority date: 1966-07-28
Filing date: 1966-07-28
Publication date: 1969-02-18
Anticipated expiration: 1986-02-18
Also published as: AT295410B; SE330122B; NO123783B; FI47854C; FI47854B; BE695805A; GB1176733A; NL6705044A; CH464672A; ES338968A1; DE1561416C3; DK128343B; DE1561416A1; FR1514567A

Description

Feb. 18, 1969 E. E. WAGNER 3,427,932

APPARATUS FOR ATTACHING CQNTAINER CQVERS BY ADHESIVE. MEANS Filed July 28, 1966 Sheet of 2 Feb. 18, 1969 E. E. WAGNER 3,427,932

APPARATUS FOR ATTACHING CONTAINER COVERS BY,ADHESIVE MEANS Filed July 28, 1966 Sheet- 2 0152 aqla lnlun 3/ F/ 6 80 J 83 G United States Patent 3,427,932 APPARATUS FOR ATTACHING CONTAINER COVERS BY ADHESIVE MEANS Edward E. Wagner, Chester, Va., assignor to Philip Morris Incorporated, New York, N.Y., a corporation of Virginia Filed July 28, 1966, Ser. No. 568,492 US. Cl. 93-55.1 12 Claims Int. Cl. B31b 17/00 ABSTRACT OF THE DISCLOSURE Apparatus for adhesively attaching cover members to body members of container units the units being preassembled and one of the members having a hinge fiap to be secured to the other member, said units being conveyed seriatim through the apparatus past elements which hold the flap distended while a band of hot melt adhesive is applied and the flap then compressed down on the adhesive area, the apparatus including automatic means precisely controlling an adhesive applicator which includes a pump for delivering adhesive to the adhesive nozzle controlled by a differential pressure valve which is automatically opened upon operation of the pump on adischarge stroke.

The present invention concerns an apparatus for intermittently applying adhesive to individual objects advanced seriatim in a defined path. It is particularly adapted for conditions where the objects move rapidly and in spaced relation and it is important that the periods of adhesive application be sharply controlled, that is the beginning and termination of each individual application is precisely controlled so that the adhesive fully covers the desired area but there is no smearing of adhesive outside the prescribed area.

As disclosed in the specific embodiment herein the apparatus is advantageously employed in sealing a hinge flap of a covered container. More specifically in the complete system disclosed herein the container body member is prefilled with its normal contents such as a bundle of cigarettes and a separately formed cap member is applied, one of the members having a hinge flap to be secured to the other member. The individual units thus preassembled are advanced seriatim past the adhesive applicator with the flap laterally extended away from the unit, a strip or band of adhesive is applied from a nozzle in the appropriate area and the unit continues in its advance past a means for holding down the flap for a period sufficient in time and under conditions for the adhesive to set adequaely. As a result of the precise controls and the character of the adhesive applicator the adhesive covers and is confined to the prescribed area.

Contributing to the effectiveness and successful operation are the construction and manner of operation of the adhesive applicator. In its specific form it embodies means or heating and supplying a hot melt type of adhesive which is adequately fluid and flowable for the purpose but sets quickly. The applicator is provided with a nozzle and a pump for delivering adhesive to the nozzle, the pump being automatically controlled in timed relation with the advance of the units through the apparatus. The pump and associated elements are so arranged that activation of the pump forces adhesive under pressure into a chamber in which is reciprocably mounted the nozzle control valve, the valve being normally urged to closed position by a spring means but quickly moved to valveopen position by the discharge of adhesive liquid from the pump, the connectioins being such that the liquid under pressure concurrently forces the valve open and directs the adhesive under pressure through the nozzle.

3,427,932 Patented Feb. 18, 1969 The combination of features described in part above operates in a most precise and dependable manner enabling very rapid operation as for example the processing of substantially more than one hundred units per minute.

The invention accordingly comprises the features, combination of elements and their relation exemplified in the particular embodiment and application of the invention disclosed in the drawings and described hereinafter. Reference should be had therefore in connection with the description to the accompanying drawings in which:

FIG. 1 is a view in elevation of the complete system but shown in part somewhat diagrammatically;

FIG. 2 is a view in perspective of one of the container units with the cover attached thereto but shown in partially opened condition;

FIG. 3 is a view in perspective of one: of the conveyor pusher elements employed at regularly spaced positions of the conveyor;

FIG. 4 is a detailed view in perspective of the cam means for triggering and controlling the operation of the adhesive applicator;

FIGS. 5A to 5D are cross sectional views taken on the planes A-A to DD respectively of FIG. I; and

FIG. 6 is a cross sectional view in elevation of the adhesive applicator.

FIG. 1 shows an apparatus and system comprising a representative embodiment of the principles of the invention. In this embodiment the units operated on comprise containers such as cigarette packages having in finished form a cover permanently attached by a hinge to the body member, one such unit U being shown in perspective in FIG. 2.

The showing in FIG. 1 is somewhat diagrammatic but in general it includes a closed chain conveyor 10 entrained around a pair of sprockets 11 and 12, one of which, for example sprocket 12 which is secured to its shaft 13, being positively driven by a suitable source of power and appropriate connections.

The chain conveyor operates in its upper run between" two spaced flat

horizontal ways

14 and 15 as indicated for example in FIGS. 5A to 5D, the

ways

14 and 15 being provided with

guides

16 and 17 respectively adapted to engage the ends of the units U. The conveyor chain is provided at equally spaced positions therealong with special pusher elements 20 on of which is shown in perspective in FIG. 3. The details of the pusher elements may vary but in the present form it includes a pair of links 21 of inverted T-shape connected by a stepped diameter cross pin 22 on which is mounted the pusher element 23 which has a downwardly extending lug 24 through which pin 22 extends. The element has a forward face 25 adapted to engage against the units U and a rear portion 26 adapted to ride on the normal chain rollers as indicated in FIG- URE 3.

The units are fed to the conveyor by any suitable means appropriate to the circumstances including the kind of unit, a delivery chute being indicated at 30 in FIG. 1 as representative of a supply source. In the present system the units U are cigarette packages including a body mem- 'ber 31 and a cover member 32, the apparatus being especially well adapted to operate on units of this character in which the body member is comprised of deep drawn plastic material of the character disclosed in the patent to Wiley et al. No. 3,167,104 issued January 26, 1965. The cover member 32 may likewise be of drawn plastic material. One of the

members

31 and 32 is provided with a hinge flap such as that shown at 33 formed integrally with the cover member 32. As noted above the units are delivered to the conveyor 10 by any suitable means. For example in the case of the cigarette packages they may be delivered from an accumulated supply or they may come directly from a packaging machine in which the contents comprising a bundle of cigarettes have been preinserted and the cap member applied resulting in a unit such as that indicated in FIG. 5A. Normally the bundle of cigarettes will be contained in a foil wrapper. Also various labels may have been applied in accordance with common practice. In the specific embodiment illustrated here the cover member 32 is formed with the flap member 33 extended at an angle such as that shown in FIG. 5A. In orther words being formed of plastic material and with the flap at an angle to the back wall it is inherently flexibly biased to that position.

Successive containers are picked up by the conveyor pusher elements 20 each one advancing a package in spaced relation from the preceding one to the several stations where the operations of applying the adhesive and holding down the flap 33 and securing it in that position are performed. FIG. 5A shows the initial condition of the unit on the conveyor in which the flap is extended at an angle to the container and is advanced through the guide 17 located at that end of the container. As the container is advanced to the next significant position shown in FIG. 5B the flap is engaged by a guide surface 40 on the end guide 17 which progressively moves the flap in the further opened direction to the position indicated. The units then proceed past the adhesive applicator indicated in general at 41 which is provided with a nozzle 42 arranged to deposit a strip or band of adhesive at the point 43 (FIG. SE) at the juncture between the flap 33 and the body member 31. The unit continues on past the area indicated in FIG. SC in which the end guide is provided with an inclined camming surface 44 which progressively irons down the flap 33 onto the body member 31 and helps to spread sufiiciently the adhesive over the surface of the flap member.

The conditions may be selected such that the adhesive material is applied at an area 43 whereby a small amount will extend through onto the foil wrapper of the cigarette bundle and serve to assist in securing the bundle within the body member. As indicated this is an auxiliary feature which may or may not be employed dependent upon the character of the unit and the circumstances.

From the position 5C the container progresses on to the position shown in section 5D where the end guide 17. or as indicated a supplementary guide 17a, engages the container and has a flap hold down section 46 for ironing down the flap and holding it in that postion for a period of time suflicient to set the adhesive which preferably is a hot melt adhesive as will be described shortly. The conveyor means and the hold down section 46 may be of sufficient length to insure the holding of the flap for a time sufiicient to set the adhesive which, however, in the case of hot melt need be of rather short duration. Other means may be employed for insuring that the flap is held down for a sufliciently long period as, for example, the units may be delivered to some auxiliary means for that purpose independent of the conveyor 10. If desired or found expedient in certain cases the hold down member may be cooled by auxiliary means.

An important feature of the present invention is the character of the adhesive applicator 41 in conjunction with a control means for rendering it effective at appropriate moments and for appropriate periods of time. The control means for the adhesive applicator may vary in details such as comprising a mechanical arrangement or a system employing a photoelectric cell responsive to the presence of a unit at a particular point. The present apparatus embodies a particularly effective and accurate control and one which is readily adjustable to provide the precise control of the adhesive applicator desired. It consists essentially of a cam means 50 driven in exact timed relation with the conveyor by a suitable drive connection such as is indicated in FIG. 1 by means of a chain 51 connected to the shaft 13 of the sprocket 12, the drive 51 being connected to the shaft 52 on which is fixed the cam 50. The cam means not only controls the intermittent initiation of the application of adhesive but also the termination and duration of the adhesive application at the nozzle 42. For this purpose the cam is made in two

sections

53 and 54 each adjustably secured on shaft 52. For such adjustment cam 53 is secured to the shaft 52 by a set screw 55 extending through the hub 53a integral with cam 53. Cam 54 may be similarly secured to shaft 52 or, as shown, it may be adjustably secured to cam 53 by means of a clamping bolt 56 secured at its inner end to cam 54 and extending through an arcuate slot 57 in cam 53 and clamped therein. Cam section 54 is pre-timed so that its lobe initiates the application of adhesive and the cam section 53 is set to a position such that its lobe determines the termination of the application cycle.

The cam means 50 actuates a microswitch 60 which includes a roller 61 mounted on the switch operating finger 62 the roller having a width sufficient to engage both

sections

53 and 54 of the cam means. As will be described hereinafter the microswitch 60 is connected to a solenoid indicated in general at 63 which operates a valve 64. The solenoid and valve means may be of standard construction and the details thereof are not of importance with respect to the present apparatus and invention. The solenoid and microswitch are connected into a suitable electric circuit, the terminals of which are indicated at 65. Air under pressure is supplied to the valve 64 through pipe 66 in which may be located a suitable pressure regulator 67.

The details of the adhesive applicator unit 41 are shown in the cross sectional view of FIG. 6 and in general outline in FIG. 1. The unit 41 is mounted on the machine by any suitable means as by insulated rods extending through holes 41a in the main casing. The applicator includes a hopper 70 in which is maintained a supply of adhesive which in the present case comprises chunks or pellets of hot melt adhesive. The unit is provided with suitable means for heating the hot melt and maintaining a supply of the adhesive in flowable form in the lower portion of the hopper as indicated at 71. The heater means which may be of electrical resistance type, indicated generally at 72 (FIG. 1), is connected to an electrical supply source by the lines 73 (FIG. 1). An automatic temperature control of conventional type is embodied which includes the thermistor probes indicated generally at 74 (FIG. 6). The details of the heater elements and the automatic control are not important to the present invention and may vary considerably in character.

The hot melt adhesive is heated to flowable form and feeds into chamber 75 through cylindrical screen 75a. Chamber 75 is connected through the passage 76 to the valve chamber 77, this latter chamber also being provided with a cylindrical screen 78.

The valve member includes an upper portion 79 of enlarged diameter and a lower portion 80 of smaller diameter, the portion 79 presenting a shoulder constituting a differential piston arrangement. From the chamber 77 the adhesive is adapted to flow down along the stem 80 of the valve member through the annular space 81. The lower end of valve stem 80 is provided with a ball portion 82 adapted to seat over and control the nozzle passage 83. The valve member is normally urged in the downward closed position by a spring 84 engaged between the upper end of the differential piston portion 79 and a fixed portion of the unit. The upper end of the chamber in which operates the piston 79 is vented back to the main adhesive chamber through the horizontal passage 85. The upper end of the unit above the valve means embodies an air cylinder and piston arrangement which includes cylinder and the piston 91 operative therein, the piston 91 having connected thereto a plunger 92 which extends down in and operates in the chamber 75. Suitable packing means are provided for the elements including the packing indicated at 93 for the plunger 92.

In the operation of the system, when the lobes on the cam means 50 operate the switch 60 and in turn energize the solenoid 63, air pressure is admitted by means of the valve 64 through the pipe 100 into the upper end of the cylinder 90, the exhaust is opened through pipe 101 which causes the plunger 92 to move down instantly and the lower end of the plunger enters the cylinder area 102 exerting high pressure on the liquid adhesive then confined therein forcing adhesive down into the chamber 77 where it operates on the differential piston 79 to lift the valve member, and concurrently adhesive flows down through annular space 81 of the valve member and out the nozzle passage 83 onto the container, as heretofore described. The container at this time is moved horizontally and when the cam roller 61 reaches the end of the cam lobes the microswitch 6.0 operates through the electrical connections to solenoid 63 to reverse the valve 64 which opens the line 100 to exhaust and directs high pressure air through the pipe 101 into the lower end of the cylinder 90 instantly lifting the plunger 92 whereupon the pressure is released from the lower end of differential piston 79 and the spring 84 quickly moves the ball valve portion 82 into its seat terminating the application of the adhesive.

Although other types of adhesive may be employed dependent upon circumstances, the hot melt type is particularly advantageous in the present system and in connection with the type of container unit being operated on. Hot melt adhesives are a well known type characterized particularly as achieving a solid state and resulting strength by cooling as distinguished from an adhesive which achieves a solid state through for example evaporation of a solvent. It is readily converted by heat from the normal solid state into a flowable state and when freed from the heat source quickly assumes the solid state and bonding effect. A wide range of materials can be employed as hot melt adhesives as, for example, natural and synthetic waxes and resins including mineral, vegetable and petroleum waxes; alkyde, terpene resins, heat-stable phenol-formaldehyde resins, and rosin and its derivatives. The strength of these materials can be enhanced by blending them with higher weight polymers including ethyl cellulose, polyvinyl acetate and derivatives thereof, butyl methacrylates, polyethylene, polystyrene and styrene copolymers, and polyisobutylene.

The combination of the hot melt adhesive, the applicator illustrated in FIG. '6, and the associated controls result in a very effective and efiicient system for adhesively securing the hinged covers. The system depicted has a high capacity capable of delivering containers at a rate considerably in excess of 100 units per minute. It is very dependable but, however, embodies the feature of automatically indicating any unit in which the hinge flap is not secured. This results from the fact that the hinge flap is originally formed at an angle to the back wall and in relaxed condition assumes that position, as indicated in FIG. A. Accordingly it is inherently flexibly biased to that position and if the bond is not secure after the unit passes through the hold down area indicated in FIG. 5D the flap will spring out to the original angle.

It should be understood that various changes may be made in the above-described apparatus and system and different embodiments of the invention could be made without departing from the scope thereof, and it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. Apparatus for attaching a cover member to a body member, one of said members having a hinge flap, and said members being pro-assembled as container units respectively, said apparatus comprising a conveyor system for advancing said units seriatim, means associated with said conveyor system in the path of said units for temporarily holding said flaps in a laterally extended position, nozzle adhesive application means in said path for applying a strip of adhesive across an area of each said unit in a position for sealing said flap to the other member, and means in said path for thereafter folding down said flap onto the said other member and enclosing the adhesive between said flap and said other member.

2. Apparatus in accordance with claim 1 in which the flap is integral with the cover member and the adhesive is applied to the body member at an area onto which the flap is folded.

3. Apparatus in accordance with claim 1 in which the adhesive applicator embodies means for heating and applying a hot melt adhesive.

4. Apparatus in accordance with claim 3 provided with control means to cause the adhesive applicator to be operated to extrude intermittently and successively charges of adhesive through a nozzle each for a limited period appropriate to the temporary presence of a unit.

5. Apparatus in accordance with claim 1 in which said adhesive applicator is operated intermittently in timed relation with the conveyor system to limit the discharge of adhesive to provide appropriate adhesive areas.

'6. Apparatus in accordance with claim 1 which includes means for holding the folded down flap for a sufficient period to enable the adhesive to form a permanent set.

7. Apparatus for attaching covers having hinge flaps to body members of container units the corresponding cover and body member of each unit being preassembled, said apparatus comprising a conveyor system for advancing said units seriatim, means associated with said conveyor system in the advancing path of said units for temporarily holding laterally extended the respective flaps, an adhesive applicator in said path for applying a strip of adhesive across an appropriate area of such unit as it advances with the flap so extended, means in said path for thereafter folding down said flap onto the unit over the adhesive area, and cam means operated in timed relation with the advance of said conveyor means, and connecting means therefrom to control the operation of said adhesive applicator whereby said applicator is operated intermittently and for a limited period in each case to apply an appropriate strip of adhesive to the respective units as they advance past the applicator.

8. Apparatus in accordance with claim 7 in which said connecting means from said cam means embodies an electrical circuit including a switch operated intermittently by said cam means, and a power means for operating said adhesive applicator controlled from said electrical circuit to effect the said operation of the adhesive applicator.

9. Apparatus in accordance with claim 7 in which the adhesive applicator comprises a unit embodying means for heating and delivering a hot melt adhesive.

10. An adhesive applicator comprising a reciprocating piston type pump, a source for supplying adhesive to said pump, means for intermittently operating said piston on a discharge stroke, an adhesive discharge nozzle, a valve chamber associated with said nozzle, a valve member controlling said outlet mounted for reciprocation in said chamber independently of said pump piston, said valve member having an enlarged rear piston portion and an outer reduced nozzle outlet controlling portion, spring means for urging said valve member forward to nozzle closed position, and fluid conduit means connecting said currently through the nozzle outlet.

11. An adhesive applicator in accordance with claim 10 in which the adhesive is of a hot melt type and the applicator has associated therewith a means for heating and supplying the hot melt to the pump.

12. An adhesive applicator comprising a casing having therein a supply reservoir for hot melt type adhesive,

means for heating the adhesive to liquid form, a pump, power means adapted to operate intermittently said pump, said pump having a fiuid conduit connection to the liquid adhesive supply, an adhesive discharge nozzle, a valve chamber and a valve including a plunger portion operable in said chamber arranged to control liquid discharge from said nozzle, a liquid connection from said pump to said chamber, said valve plunger being provided with a differential piston operative in said chamber whereby the intermittent delivering of liquid under pressure from said pump operates on said plunger correspondingly to open intermittently said valve.

References Cited UNITED STATES PATENTS BERNARD STICKNEY, Primary Examiner.

US. Cl. X.R.