Blowing- And Filling Thorn

Abstract

A blowing- and filling-thorn for production of hollow bodies, in particular ottles, of thermoplastic synthetic material in a blowing process and for filling this hollow body, which comprises as a blowing tube mounted axially displaceable and having at least one blowing air channel. A filling tube is coaxially slidably mounted in the blowing tube, and has a filling valve in front of the mouth of its filling channel. At least one airing channel, is provided and the mouth of the blowing air channel and of the airing channel, in case the filling tube is moved into the blowing tube, is disposed diametrically opposite each other on a circular line comparatively narrowly surrounding a plate of a filling valve. The blowing tube is equipped with an annular deflection edge, overreaching the mouth of the blow air- and airing-channels on the outside, and is bent at a distance thereto inwardly in the direction toward the filling tube up to its outer circular line, and has air passage openings.

Description

The present invention relates to a blowing- and filling-thorn for an apparatus for production of hollow bodies, in particular bottles of thermoplastic synthetic material in a blowing process, and for filling these hollow bodies, with a blow tube axially displaceably mounted, and having at least one blow-air-channel and a filling tube coaxially displaceably mounted in the blow tube, and having a filling tube including a filling valve in front of the mouth of its filling channel, as well as at least one airing channel.

During blowing and filling of hollow bodies of synthetic material the blowing- and filling-thorn performs a plurality of functions, as blowing, filling, airing and suction of foam, for which purpose it has a plurality of channels with valves to be opened and closed at different time intervals. By this arrangement in particular the thorn for the production of narrow-necked bottles becomes complicated and expensive. Particularly, if the thorn is used for filling of fat-containing foods or liquids, respectively, as by example milk in bottles of polyvinylchloride, additional measures must be taken against after-dripping of the filling liquid, as well as for a thorough rinsing of the hollow bodies prior to filling.

It is one object of the present invention, to provide a blowing- and filling-thorn simple in its structure which thorn fulfills all required functions without objection, even by use of polyvinylchloride as container material.

It is another object of the present invention, to provide a blowing- and filling thorn, wherein the terminals of the blow air channel and of the airing channel are diametrically disposed relative to each other with the filling tube inserted into the blowing tube about on a circular line comparatively narrowly surrounding the plate of the filling valve. The blowing tube is equipped with an annular deflection edge, overreaching the mouth of the blow air-and airing-channels on the outside, and is bent at a distance thereto inwardly in the direction toward the filling tube up to its outer circular line, and has air passage openings.

By this arrangement it is brought about, that all required functions are performed with three channel systems only. Furthermore a favorable arrangement of these three channels in the thorn in narrowest space has been found, with which during the blow- and filling procedures a reverse rinsing in the space of the hollow body is made passible and with which a drop disposed on the lower thorn can be blown off without an expensive suction device controlled by valves directly after the filling process. The blow air is directed in advantageous manner after the filling process so tight below the filling valve, that the collecting liquid drops are blown off and do not influence during the following blow process the container material.

With these and other objects in view which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood in connection with the accompanying drawings, in which:

FIG. 1 is an axial section of the lower broken up end of a blowing- and filling-thorn, in accordance with a first embodiment shown by example in a closed blow form, with a partly moved-out filling tube;

FIG. 2 is a section similar to that of FIG. 4 with a moved-in filling tube after the filling process;

FIG. 3 is a section along the lines A--B of FIG. 1;

FIG. 4 is a section along the lines C--D of FIG. 1; and

FIG. 5 is a cross section of FIG. 2 of a blowing- and filling-thorn in accordance with a second embodiment.

Referring now to the drawings and in particular to FIG. 1, a divided blow form 10 for a blow- and filling-machine is shown in closed position. On its wall surrounding the upper opening, sits a blow- and filling-thorn 11, shown fragmentary with an adjoint conical piece, which clamps tightly the end section of a hose-like extruded form blown up to a hollow body 12 and still being in its plasticizing heat. The blow- and fill-thorn is in known manner mounted axially displaceable in the vertical center plane of the blow-head of the blow- and filling-machine.

In the first embodiment in accordance with FIGS. 1-4, the blow- and filling-thorn contains a relatively thick walled blow tube 13 with its already mentioned conical adjoint piece annularly surrounding within the range of the mouth on the outside for mounting the thorn to an adjusted face of the blow form-opening. Along through the blow-tube six channels 15 and 16 extend through their wall, which are disposed, as shown by the cross-section in FIG. 3, adjacent each other on a circular line in diametrically arranged groups of three channels each. On the mouth side the channels terminate open, while they are connected on the opposite side in the blow-head in groups with feeding and removing systems for the blow-air and for the airing (not shown) and valve-controlled. As it is indicated in FIGS. 1 and 2 by arrows, the channels 15 of one group are connected with the feed line for the blow-air and the channels 16 of the second group disposed diametrically to the first group are connected to the feed off portion for airing of the hollow body.

Below the conical connection 14, the blow-tube is equipped with a deflection edge 17 which is annular shown in FIG. 4 in cross-section, overreaching the mouth of the blow-air and airing-channels on the outside and bent over inwardly to the channel mouth at a distance to this channel mouth. The annular gap formed between the mouth edge and the deflection edge is made by two separation stays 18 disposed diametrically to each other to two annular gap-halves 19 and 20. The one annular gap-half 19 is disposed below the first group of the channels 15 and the second annular gap-half 20 is arranged below the second group of the channels 16. In the side wall of the deflection edge 17 are provided a plurality of air passage openings 21 disposed on a circular line. The inner diameter of the bent over edge part corresponds to the inner diameter of guide and bearing sections 22, which are arranged in the blow-tube on the inside within the range of the mouth and of the blow-head (not shown) for mounting and guiding of a filling tube 23.

The filling tube 23 is mounted coaxially and displaceably in the longitudinal direction. It is capable of travelling out up to the bottom of the blow form 10 out of the blow tube and has in front of this side of the mouth opening a plate 24 of a filling valve, the shaft 25 of which extends within the filling tube up to a control device (not shown) in the blow head.

The operation of the blow- and filling-thorn is as follows.

After insertion of a hose-like form or briquet into the blow form 10 and its closing, the blow- and filling-thorn sits with its conical adjoint piece 14 on the opening edge of the form. Thereafter the form with its lower edge section between the bottom closing edges of the blow form and with its upper edge section between the head-sided opening edge of the blow form- and the blow-tube extension is set. The filling tube 23 is thereby in the position travelled into the blow-tube 13, as it is shown in FIG. 2. The blow-air required for the blowing up of the form through the first group of the channels 15 and the completely opened deflection edge 17 by means of airing channels 16 closed by valves (not shown) into the hollow space of the form and forms the latter with sufficient pressure, build-up to a hollow body.

Thereafter the fill-tube 23 moves out of the blow-tube, whereby the large opening, disposed in the inner circle of the annular deflection edge 17 is closed by the filling-thorn. During this procedure takes place a thorough rinsing of the hollow body, since further blow-air is pressed from the channels 15 through air passage openings 21 on this side of the deflection edge 17 into the hollow body and is fed off jointly with gas remainders from the heated material of the hollow body through the oppositely disposed air passage openings of the deflection edge and the now completely opened airing channels 16. Simultaneously the wall of the hollow body cools up sufficiently so that any further gas development is avoided. If necessary, the described reverse rinsing can be continued during the following filling process.

After the filling process, in which the filling tube 23 closely below the liquid level is moved upwardly with the latter and is moved completely again into the blow-tube, as shown in FIG. 2, the plate 24 of the filling valve, which is closed again, renders free the space disposed within the deflection edge 17 between the mouth of the diametrically disposed blow-air channels 15 and airing channels 16 for a direct air passage. The blow-air guided by means of the deflection edge 17 below the valve plate 24 blows off liquid drops collecting at the form end.

For the filling of strongly foaming liquids a hose 26 of a suction device (not shown) and provided in the blow head is connected with the airing channels 16, which suction device sucks up by means of one or more of the channels 16 the foam as well as, under circumstances, the drops collecting at the thorn into a collecting container. For the complete suction of the foam the liquid level of the completely filled hollow body is arranged below the channel mouth, thus about at the height of the thorn-lower-edge. The blowing or suction of the liquid drops takes place directly after the lifting of the thorn from the blow form.

In FIG. 5 the cross-section of the blow- and filling thorn is shown in accordance with the second embodiment. Thus merely the blow-tube 27 distinguishes from the blow-tube 13 of the first embodiment in its structure. The blow-tube 27 is produced of two tubes 28 and 29 disposed concentrically within each other. Their walls are kept spaced apart of each other by means of a uniform distance forming an annular gap and are connected in two sections diametrically disposed from each other by two separation walls 30 disposed passing through in longitudinal direction. Thereby an annular gap formed between the tubes is divided into two channels 31 and 32 disposed diametrically opposite each other, which corresponds with the channel-groups 15 and 16 of the first embodiment. With the exception of this simplified structure of the blow-tube, the thorn is identical with that of the first embodiment and is further substantially equal in its operation.

In both embodiments the blow-tube 13 or 27, respectively, has within the range of the mouth sitting on the blow-thorn 10 the already mentioned conical adjoint piece 14 extending annularly on the outside, with which adjoint piece 14 the blow-tube comes into rigid contact with the hot form and thereby is exposed to a strong heating. The cooling of the blow-tube takes place at least partly by the air streaming in its channels 15 and 16 or 31 and 32, respectively. Beyond that, within the range of the conical adjoint piece 14 on the inner side of the blow-tube, a likewise annular guide- and bearing-section 22 is arranged for the moving-in and moving-out filling-tube 23. The face contact causes feeding away of the heat onto the filling-tube and the mostly cold filling liquid. By this arrangement a strong heating of the blow-tube and thereby an undesirable expansion of its mouth part is avoided, which leads to an extensive maintenance of the wall thickness in the head of the hollow body.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense.

Claims

I claim:

1. A blowing- and filling-thorn for production of hollow bodies, in particular bottles, of thermoplastic synthetic material in a blowing process and for filling this hollow body, comprising

a blowing tube mounted axially displaceable and having at least one blowing air channel,

a filling tube coaxially slidably mounted in said blowing tube, and having a filling valve in front of the mouth of its filling channel,

at least one airing channel,

the mouth of said blowing air channel and of said airing channel, in case said filling tube is moved into said blowing tube, being disposed diametrically opposite each other on a circular line comparatively narrowly surrounding a plate of a filling valve,

said blowing tube is equipped with an annular deflection edge, overreaching the mouth of said blow air-and airing-channels on the outside, and bent at a distance thereto inwardly in the direction toward said filling tube up to its outer circular line, and having air passage openings.

2. The blowing- and filling thorn, as set forth in claim 1, wherein

said blowing tube comprises two tubes, disposed concentrically and with an annular gap defining channels in each other, and connected together by means of separation walls diametrically disposed relative to each other, and

the lower edge section of the outer of said tubes is formed to said deflection edge.

3. The blowing- and filling-thorn, as set forth in claim 2, wherein

said airing channel is connected with a suction device having a suction hose and the latter is attached to said airing channel.

4. The blowing- and filling-thorn, as set forth in claim 3, which includes

a blow tube,

a conical adjoint piece extending annularly and mounted on the outside of said blow tube,

said blow tube having on its inner side within the range of said adjoint piece a likewise annular guide- and bearing-section for said filling tube.