NZ227136A - Blow moulded plastics container with three injection moulded handles - Google Patents

Description

Patents Form # 5 22 7 1 3 6 c *w o Priority Date(s): Complete Specification Filed: Class: c.-?a I v-r; f."u Publication Date: . — 2. &-l^AR-199|-P.O. Journal, No: rr.....

NEW ZEALAND Patents Act 1953 a COMPLETE SPECIFICATION tf30H0VW88| V'? ** ,« BLOW MOULDED CONTAINER AND PROCESS FOR ITS PRODUCTION I/We, Dr. Wolfram Schiemann, German citizen, of Eugen-Nagele-StraBE 17, 7140 Ludwigsburg West Germany, do hereby declare the invention for which I/we pray that a patent may be granted to me/us and the method by which it is to be performed, to be particularly described in and by the following statement: PF05.JWP FEE CODE -1050 227136 P C 5 © The invention relates to a three-handled container as described in the preamble to claim 1 as well as a device for its production as described in claim 6 and a process for its production as described in claim 8.

A container as described in the preamble to claim 1 is disclosed in the German Patent 21 51 913, available on request. A device for its manufacture is disclosed in the German Patent Specification 19 27 014, also available on request. A three-handled container naturally has three handles, so that when they are empty two external handles of neighboring containers can be grasped with one hand and thus four containers can be carried in all. If the container is full, it is carried by the central handle, the weights of containers of this type including contents may be considerable. The standard three-handled container holds 20 liters. There are, however, also 30 liter containers. The external handles of conventional containers comprise injection molded material. It is known that injection molded components, although having the same base material, are essentially more rigid than blown components and are also much smoother, this being due to a difference in the pressure of production greater than a factor of 100. They are thus of high quality where stress characteristics and carrying characteristics are concerned. The central handle however has an essentially rougher surface. It may be that this is of little importance, 22 7 1 3 6 if a container is carried occasionaLLy. If however many containers must be carried, as is necessary for example when supplying the population during disasters or when for example the tanks of an aircraft which contain many cubic meters have to be filled from containers, the difference between a small and a high degree of surface roughness is very quickly noticeable and it is also very quickly noticed whether flashes are present or not.

As the central handle is made from the same pari-son material which the extruder extrudes, only the doubled material thickness of this parison is available as a volume for producing the central handle. This means that the central handle remains relatively narrow, so that it cuts into the hand during carrying. Thus success has not yet been had in the case of plastic containers, with what has been known since the 1940s with metallic three-handled containers: namely making the central handle wider and easy to carry and particularly with a low degree of surface roughness and without substantial flashes.

In the case of plastic containers, the central handle had also to be kept substantially shorter, since it is made from less rigid material. Thus no success has been had with making this handle as long as has been the case with metal containers for a long time.

Moreover the central handle is situated at a lower level than the two external handles. This is done, because it is not particularly capable of withstanding stresses for example if dropped, or stacked. This means 22 7 1 3 6 that it is difficult for a large human fist to fit into the space between the central handle and the adjacent upper side of the container, and impossible when a glove is worn. The central handle must also be located lower down for a reason - which is not apparent from the publications - which is because the two handle roots must be pinched. The tool for pinching however requires space.

As is also shown in the Figure of German Patent Specification 19 27 014, a multicomponent tool is necessary because of the numerous undercuts. This requires expenditure on the production machine, on synchronization and so on.

The object of the invention is to provide a three-handled container of the type initially mentioned, which allows the disadvantages mentioned above to be individually or collectively avoided.

This object is achieved in the invention by incorporating the features which are described in the characterizing part of the main claim.

All the handles can now be injection molded. The bonding of all handles, but particularly of the central handle to the container body, is now enhanced by the strand passing through it. The hollow space can be dimensioned in such a way that it exactly accepts the double wall thickness of the parison which is located between the halves of a central handle when the mold is closed, and is thus completely filled.

By means of the features of claim 2, a two layered course is produced in the whole region of the partial shells, namely once by virtue of the inflated parison and once by virtue of the three shells themselves. To a certain extent this also counters the swelling out of the container.

By means of the features of claim 3, simple partial shell shapes are produced and moreover, a good welding of the faces.

By means of the features of claim 4, it can be achieved if desired, that the parison is pinched by the faces themselves and not by additional metallic tools.

By means of the features of claim 5 welds are produced, and particularly, exactly symmetrical partial shells.

By means of the characterizing features of claim 6 a simpler blow molding tool is achieved despite receiving and supporting the now greater wall region including the half of a central handle.

By means of the features of claim 7 the external surface of the recessed grip can be fully supported.

By means of the features of claim 8 not only a positive but also a practical bonding involving similar materials is achieved between the injection molded partial shells and the blow molded container body. Moreover, a minimum of process steps is thereby involved, not only from the aspect of the operator but also from the machinery aspect.

The invention is now described by means of a preferred exemplary embodiment. In the drawing: 22 7 1 shows the plan view of a 20 Liter three-handLed container, the side view to Fig. 1, a perspective view of an injection molded partial shell, the schematic side view of extruder, blow mold and mandrel, a section along the line 5-5 in more exact representation.

A three-handled container 11 has a body 12, which contains about 20 liters of liquid. A discharge nozzle 14 projects from a bevel 13 sloping off to the right hand side. The three-handled container 11 has a head 16, a 15 recessed grip 17 and the two larger external walls 18 and 19. Partial shells 21 and 22, shown as dotted lines, are provided as described in Fig. 1 and Fig. 2. Each partial shell is injection molded and has an external handle 23, 24 as well as a half of a central handle 26, 27. Each 20 partial shell 21, 22 comprises a wall region 28, 29 one face of which 31, 32 extends to the geometrical center line 35, which is also at the same time the parting line. The faces 31, 32 are delicately bonded together by hot parison material (Fig. 4). The leading edge 34, 36 of 25 wall region 28, 29 extends to the vicinity of the discharge nozzle 14. The wall region projects in each case with a shroud 15, 25 into the external walls 18, 19 following the surface contours of the latter. It also extends lengthwise from the left hand roots 37, 38, 39 Fig. 1 Fig. 2 Fig- 3 Fig. 4 G 10 Fig. 5 22 7 136 ~ 7 ~ x as the cap 41 over the head 16 of the three-handled container 11. It is shown in particular on the perspective representation given in Fig. 3, which shows the partial shell 22. As shown in the side 5 view in Fig. 2, there is a generally flat upper side 42, which comprises the roof of the cap 41 and the upper side of the external handles 23, 24 and the halves of a central handle 26, 27. The halves of a central handle 26, 27 have also non-overlapping faces 10 43 (outer) and 44 (inner), which are situated in the center line 33 and are delicately bonded together not only by the hot parison material 33 but by the pressure of the tool. The halves of a central handle 26, 27 have the shape of a continuous half channel 46, 15 47, which combines to form the central handle. In this hollow space formed by the half channels 46, 47, starting at the handle root 38, there is extruded parison material 48, which fills the half channels 46, 47 and is also connected in turn at the root of the 20 central handle 49 with the internal, in normal use, upper top wall 50 of the body 12, so that as it were a lug of parison material 48 extends through the halves of a central handle 26, 27. The volume enclosed within the half channels 46, 47 of the halves of a central 25 handle 26, 27 is dimensioned in such a way that it is in any event filled with parison material 48.

In production, an extruder 51 extrudes the parison material 33 as described in Fig. 4. The parting line 22 7 1 3 6 * (center Line) Lies paralLeL to the pLane of the drawing in Fig. 4. To the right and Left of this, halves of a blow moLd 52, 53 are provided, between which the parison 33 can be admitted. Moreover, a mandrel 54 is provided. 5 The haLves of the bLow mold 52, 53 each have a channel 55 for receiving the external handles 23, 24. Further, the half of the blow mold 52, 53 partly accepts the partial shells 21, 22 as described in Fig. 5. Insofar as the partial shells 21, 22 extend over the edges 56, 57 of the 10 halves of the blow mold 52, 53 towards the parting Line 35 these are maintained in the closed condition, suppor-against the internally acting blow pressure by means of the faces 60, 65 of each half of a sliding bar 58, 59. In this manner, the faces 60, 65 are continuations of 15 the inner surface of the haLves of the blow mold 52, 53 in this region. Each half of the sliding bar 58, 59 has a complementary recess 61, 62 in the region of the halves of a central handle 26, 27. The lower region of the recess 61 supports the halves of a central handle 26, 27 l*w/ 20 respectively running outwards to the left from 6 o'clock to about 10 o'clock and to the right to about 2 o'clock. Above, there is an adjacent bevel 63, 64 which lies at such an angle that the bevels 63, 64 intersect not only in the faces 60, 65 but also the parting line 35 and more-25 over form a tangent to the periphery in each case of the halves of a centralhandle handle 26, 27. The external bevels 66, 67 run parallel to this. If the direction of displacement of the haLves of a sliding bar 58, 59 22 7 1 corresponds to the arrows 68, 69 wfiich also run parallel to the bevels 63, 64, 66, 67, the outer handles 23, 24 and at same time also the halves of a central handle 26, 27 are avoided, the inner region of the wall regions 28, 5 29 is supported all over and the parison material 73 can be nipped with the corners 71,72 As may be seen from Fig. 5, doubled wall thick-0 nesses are now present, namely the upper wall 49 together with the wall regions 28, 29. The thin places which are 10 sometimes located in the region of the corners of the head due to the high draw ratio are now reliably double layered.

In operation, a partial shell 21, 22 is in each case inserted into the lower region of the halves of the 15 blow mold 52, 53 while the halves of a sliding bar 58, 59 are not yet slid in, the unspecified sprung ball bearing devices being able to assist in initially holding the partial shells 21, 22. Then the halves of a sliding bar 58, 59 are slid in via actuating devices which are not 20 shown. The halves of the blow mold 52, 53 are now still far apart. It is then ensured that the parison material 33 is running downwards. The halves of the blow mold 52, 53 are now shut and the mandrel 54 is placed in the blowing position and inflates the volume within the parison 25 material which has now been nipped. After cooling the halves of the sliding bar 58, 59 are withdrawn against the arrows 68, 69 and then the halves of the blow mold 52, 53 are opened. o u

Claims (8)

-10- 227136 WHAT I CLAIM IS:

1. A three handled blown container made from plastics material, having a plurality of walls, an upper portion, two external handles and a central handle between said external handles, said handles having handle roots in said upper portion, and a recess under said handles between said roots in the region of said upper portion; said container being formed from elements including two injection moulded partial shells, each comprising one said external handle, a continuous channel - shaped half of said central handle, and a wall region providing said handle roots and at least part of said walls, upper portion and recess; said channel shaped halves of said central handle being joined to form a complete central handle; wherein other parts of said container are comprised of blown plastics material, a wall of said blown plastics material extending across an inside face of said wall region of each said partial shell, and bonded thereto, and a continuous strand of said blown plastics material extending from said wall of blown plastics material through a space enclosed by the two channel - shaped halves of said central handle.

2. A container as claimed in claim 1, wherein faces of said partial shells are butted together in the region of a centre line of the container, without a gap.

3. A container as claimed in claim 2, wherein the faces butt flush against each other.

4. A container as claimed in claim 2 or claim 3, wherein the faces have parison - nipping properties.

5. A container as claimed in any one of claims 1 to 4, wherein the faces are located exactly on a centre line of the container.

6. A device for producing a blown three-handled container made of plastics material, using a blow mould comprising two mould halves which can be moved towards each other; in a region of each of which a partial shell may be insertedj,;^^^©^being provided to o f 271 36 -11- accept an external handle on each said partial shell; each said mould half having a sliding bar, one face of which forms at least one part of the mould wall when slid into position, wherein: w: (a) each said partial shell includes a wall region extending at least in part to the centre line of said blow mould; (0 (b) each said partial shell includes a channel shaped half of a central handle, the edges of which extend to said centre line of the blow mould; (c) each said sliding bar has a recess therein to accommodate one half of said central handle in use; (d) said face of each said sliding bar forms a part of the mould wall which projects into the mould cavity.

7. A device as claimed in claim 6, wherein said face of each said sliding bar includes an external flank, which runs tangentially to said external handle, and an internal flank, which runs tangentially to the periphery of a half of the central handle, up to the centre line of said blow mould.

8. A process for producing a three-handled blow moulded plastics container, including the following steps: Injection moulded partial shells are inserted into open halves of a blow mould, each said partial shell including an external handle, a channel-shaped half of a central handle, and a wall region, said wall region extending at least in part to the centre line of said blow mould. (a) o (b) One or more sliding bars are inserted into the mould cavity, to close around each said external handle and support each said half of a central handle from underneath. 3220CL.191/1V V- 227136 -12- (c) An extruder extrudes a hot plastic parison into the mould cavity. (d) The blow mould is closed and the parison is inflated. (e) The parison material welds said partial shells together at faces of said wall regions and the halves of a central handle. A three handled blow moulded plastics container substantially as herein described with reference to Figures 1 and 2 of the accompanying drawings. A device for producing a three handled blow moulded plastics container substantially as herein described with reference to Figures 3 to 5 of the accompanying drawings. A process for producing a three handled blow moulded plastics container substantially as herein described with reference to any one of the figures of the accompanying drawings. James W Piper & Co. Attorneys for: Dr. Wolfram Schiemann