Source: https://patents.google.com/patent/US4781012
Timestamp: 2018-07-19 04:00:59
Document Index: 283626600

Matched Legal Cases: ['arts 108', 'arts 108', 'arts 108', 'arts 7', 'arts 7', 'arts 7', 'arts 16', 'arts 7']

US4781012A - Closure device for an injection moulding apparatus - Google Patents
US4781012A
US4781012A US07109434 US10943487A US4781012A US 4781012 A US4781012 A US 4781012A US 07109434 US07109434 US 07109434 US 10943487 A US10943487 A US 10943487A US 4781012 A US4781012 A US 4781012A
US07109434
So that parallel webs of a packaging tube can be passed more closely beside one another so that it is possible to manage with a few plasticizing units in the smallest space and with short flow paths for the synthetic plastics material, it is according to the invention envisaged that the direction of conveyance of the paper web extend at a right-angle to the direction of opening and direction of closure of the mould parts, a plurality of pairs of movable mould parts being disposed adjacent one another at a distance in the opening and closing directions, the connecting levers which take the form of ties and knee levers being so articulated that during injection, the forces which arise are mutually reinforcing and the carrier can be of lighter weight construction, at least in its middle portion.
This application is a division of application Ser. No. 07/018,494, filed Feb. 25, 1987 and now U.S. Pat. No. 4,725,213 issued Feb. 16, 1988.
It will be appreciated that for the opening and closing movement of the upper mould, a minimum space is required because a not inconsiderable overall space is needed for the strongly constructed controlling and articulating parts of the injuection mould drive. Particularly when leading through the bottom moulds which take the form of mandrels mounted on a wheel, the opening and closing direction of the upper mould parts can be only sideways, i.e. at a right-angle to the direction of movement of the mandrels or bottom mould parts. Indeed, it is possible for the upper mould also be to be lifted and opened in the direction of the mandrel axis outwards or upwards but the constructions on the machine necessary for this are so cumbersome, expensive and bulky that lateral movement and control means have been found to be more expedient.
According to the invention, this problem is resolved in that the direction of conveyance of the paper web is substantially at a right-angle to the opening and closing direction of the mould parts, at least two pairs of mould parts movable relative to each other being disposed beside each other at a distance in the direction of opening and closure, the connecting levers in the form of ties and knee levers being so articulated that each pair of mould parts is guided by at least two bearing journals disposed between pairs of mould parts being articulated on the one hand through two pairwise disposed knee levers to be rotatable on the nearest mould part and an the other on a tie which is maintained stationary at one end, the two knee levers being connected to each other at a movable pivot point and to the movable carrier and in that whichever is the bearing journal which guides the outermost mould part is connected on the one hand to a tie which is maintained stationary at one end and on the other, through a knee lever is rotatably connected to the movable carrier. Despite the disposition of a plurality of pairs of mould parts adjacent to one another in their direction of opening and closure, it is possible with the new drive apparatus to achieve substantially shorter flow paths for the synthetic plastics material from one supply injector to the various injector heads. Due to the careful disposition and construction of the connecting levers and the means of guiding the drive forces through these ties and levers, the distance between adjacent pairs of mould parts can be substantially reduced. By the dispositions of a movable carrier into which the driving forces are initiated, a favourable driving and powerful supporting of the bearing journals and thus of the individual mould parts can be guaranteed in order satisfactorily to accommodate the considerable forces required. The carrier need only be of stronger construction at its ends for the mould parts which are disposed at the outer ends, while in the middle it can manage with smaller components. In the middle zone, i.e. between the pairs of mould parts, care is taken that these are braced substantially against one another without the pressures which occur in the middle zone during injection moulding having to be initiated into the movable carrier. Thus, the overall construction of the connecting levers can be smaller so that the distance between pairs of adjacent mould parts and thus the flow paths for the extruded synthetic plastics can be reduced.
According to the invention, it is furthermore advantageous if the carrier takes the form of a comb having end arms and middle arms, on whichever is the free end of which there is the movable pivot point. The relatively light form of the middle part of the carrier has already been explained hereinabove. By the provision of middle arms of smaller dimensions, the entire carrier can be kept relatively small and light in weight, only the end arms having, at the beginning and end of a chain of pairs of mould parts, to move whichever is the outermost mould part and accommodate the pressure forces exerted for it. This moving carrier expediently supports the supply injector and also the individual injector heads, and permits the disposition of hot ducts, i.e. the conductors for the extruded synthetic plastics material from the supply injectors to the individual injector heads.
By adopting the measures according to the invention, therefore, the use of the aforedescribed apparatus is particularly advantageous when manufacturing packagings for liquids where an end wall of synthetic plastics material is injection moulded on the paper tube by the packaging, the side walls thereof being constituted by the tube and consisting of a paper coated on both sides with synthetic plastics material, packagings for liquids, particularly milk and fruit juices, are a mass produced item for which high output manufacturing machines are required. Dairies or fruit juice manufacturers do not, however, have a lot of space available to accommodate the packaging machines and therefore expect a high rate of output on a minimal floor area. The output of the new packaging machine when using the driving device according to the invention is unexpectedly high with a perfect injection moulding of the individual parts.
FIG. 6 is a plan view of a diagrammatically disposed different device for injection moulding an opening device into the prestamped hole in a paper web;
FIG. 7 shows the development of the moulding space in the region of the stamped outhole in the paper web in a sectional view taken centrally through the opening device which is to be produced and with diagrammatically shown mould parts;
Shown in FIGS. 1 to 5 is a device for producing liquid packagings in which an end wall consisting only of synthetic plastics material is injected at one end on the tubular side walls of the packaging. Manufacture takes place in broad stages, as can best be seen in FIG. 1. From the roll 1, the paper strip 2 runs in a direction of the arrow A over a first guide roller 3 in position I over further reversing and pull-off rollers not shown in greater detail but which are finally so driven with an intermittent action that after the necessary marking and score lines have been applied, the strip is fed into the cutting apparatus 102. Here, the strip is separated into four portions which are then passed by conveyor means 60, 61, 62 from position II to position V. On the way, the initially flat blank is folded up into a tube which is pushed along a mandrel. In position VI, the package has reached the first mandrel 4 on a mandrel-carrying wheel generally designated 36 and which rotates in a clockwise direction as viewed in FIG. 1. The injection apparatus is generally designated 37 and is disposed above the wheel 36. Also shown is the injector head 5. After the end wall 6 of the package shown in FIG. 8 has been integrally moulded, the tube is rotated from the vertical downwards into the horizontal and through a further 90° downwards into position IX from which the tube is pulled off downwards into position X. Now the paper tube 107 is located in receiving parts 108 which are disposed adjacent one another, as can also be seen in FIG. 2. These receiving parts 108 belong to the conveying apparatus generally designed 38 in FIG. 1 and which consists of an endless chain of rows of receiving parts 108, and which passes over guide wheels 39. When the relevant row of packages, after leaving position X, reaches the filling station 40, the package which is open at the top and closed at the bottom is filled and at station 41, the height of the package, i.e. the top edge of the paper tube, is brought to an exactly defined height before closure taken place in station 42. At station 43, the bottom of the package is folded in that triangular flaps are formed which project upwardly. At 44, there is a hot air blowing device for heating the outer surfaces and folding over the triangular flaps on the bottom of the package. This folding over occurs during onwards transportation from station 44 to station 45 and is achieved by suitable sliding bars. Reference numeral 45 denotes a co-rotating pressure-applying station which extends beyond at least two rows of packages. At every two strokes, this station 45 applies pressure to the triangular flaps, i.e. two serially disposed packages, so that the pressing time is extended. In the almost horizontal direction in position 46 (on the right in FIG. 1), the package is now ejected onto a conveyor chain, not shown.
The injection moulding apparatus 37 shown in FIG. 2, with upper mould parts 7 and 8 is more clearly shown in FIGS. 3 to 5. Of the mandrel-carrying wheel not shown, these drawings only show in each case the paper tube 107 which forms the side walls of one embodiment of package 13. FIG. 3 shows two working conditions, in the left-hand half the injection condition with closed mould parts, 7, 7' and 8, 8' while in the right-hand half is shown the other condition in which the mandrels with the paper tubes 107 can pass through the opened upper mould parts 7", 7"' and 8", 8"'. Thus it is possible right away to see the opening direction 14 and closing direction 15 of the mould parts 7 and 8. (Articulation and movement of the mould is described mainly with respect to FIG. 3 and with regard to one station, it being understood that the other stations provided with one or more apostrophes operate in the same manner.) The distance X between two separately disposed injector heads 5 or pairs of mould parts 16 is made possible by the favourable disposition of the connecting levers which will be described in greater detail hereinafter.
FIGS. 3 and 4 likewise show the comb-like form of the movable carrier 9 particularly clearly, namely with its middle arms 22 and end arms 23.
In FIG. 6, the paper web 2 is drawn from a supply roll 1' in the direction of the arrow A and passes zig-zag-wise several times, in this case five times, over guide rollers 67, six of which are shown here, and through a chain of injecting apparatuses 37. Let it be assumed that there are in the paper web 2 prestamped holes 67' which are spaced apart from one another in the direction of movement A, in such a way that when the entire web is stopped at the station shown in FIG. 6, one hole 67' is positioned exactly opposite each of the injector heads 5. The drawing shows here only the mould halves 7, 8; 7', 8', etc., which are grouped together in pairs; with bearing journals 19 and the layers of movable pivot points 21. The opening device 63 according to FIG. 9 is likewise shown in FIG. 6 as already injected at the end of the web 2 which is on the discharge side. FIG. 6 shows that the relevant plane of the paper web 2 which is guided through the chain of injection devices 37 always extends at a right-angle to the opening and closing movement 14, 15 of the mould parts 7, 8.
Furthermore, weakening lines 72 can be seen, one of which is directly alongside the gripper strip 69 and serves as a tearopen aid. As illustrated in FIG. 10, the opening device 63 can be opened along this possibly endlessly extending line of weakness 72.
1. A method for simultaneously producing a plurality of plastic endwalls having releasable, injection molded, closures thereon comprising the steps of:
a. moving a plurality of flat container endwalls, each defining an aperture therein, to a first predetermined point adjacent opened, closure mold parts with injection molding heads as portions thereof;
b. bringing a predetermined quantity of heated injection molding material to injection molding heads at said first point;
c. shutting said closure mold parts together over each of said aperatures to form a cavity thereon and flowing the material through said heads into the aperture within the closed molds;
d. opening said mold parts; and
e. moving said plurality of endwalls to a second predetermined point.
2. A method as in claim 1 including the step of attaching containers to said endwalls prior to the movement thereof to said first predetermined point.
3. A method as in claim 2 including the step of filling said containers prior to the movement to said first predetermined point.
4. A method as in claim 2 wherein the moving of said endwalls is accomplished by placing each said container on a mandrel.
5. A method as in claim 1 wherein the steps of moving a plurality of container end walls includes the step of bringing strips of paper webbing to said first point at substantially right angles to the opening and closing direction of said mold parts, wherein at least two pairs of mold parts are disposed alongside each other and moving members of each pair together and apart to close and to open the molds about said strips by connecting levers in the form of ties and knee levers.
US07109434 1986-02-27 1987-10-15 Closure device for an injection moulding apparatus Expired - Fee Related US4781012A (en)
US07018494 Division US4725213A (en) 1986-02-27 1987-02-25 Closure device for an injection moulding apparatus
US4781012A true US4781012A (en) 1988-11-01
EP0388647A2 (en) * 1989-03-21 1990-09-26 Tetra Laval Holdings &amp; Finance SA Process and apparatus for closing a package for liquids
US20060008553A1 (en) * 2002-11-29 2006-01-12 Gunnar Dike Injection moulding device and a method of opening and closing a partible mould in an injection moulding device
EP1042178B1 (en) 1996-10-31 2003-02-26 Tetra Laval Holdings &amp; Finance SA Packaging container having an opening device
DK0949992T3 (en) 1996-10-31 2003-03-10 Tetra Laval Holdings & Finance An apparatus and method of molding an opening device on a packaging sheet
DE20303387U1 (en) * 2002-12-06 2003-05-15 Tetra Laval Holdings & Finance Opening device with a guarantee seal and packaging with such an opening device
DE20303386U1 (en) 2002-12-06 2003-05-15 Tetra Laval Holdings & Finance Opening device and packaging with such an opening device
US7313895B2 (en) * 2004-07-20 2008-01-01 Tetra Laval Holdings & Finance, Sa Molding unit for forming direct injection molded closures
EP0388647A3 (en) * 1989-03-21 1991-03-27 Tetra Laval Holdings &amp; Finance SA Process and apparatus for closing a package for liquids
US5052994A (en) * 1989-03-21 1991-10-01 Tetra Pak Holdings & Finance Method of and an apparatus for sealing a liquids package
US4725213A (en) 1988-02-16 grant
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