GB2257924A

GB2257924A - Mixing head

Info

Publication number: GB2257924A
Application number: GB9211965A
Authority: GB
Inventors: Klaus Pontius; Manfred Settinger
Original assignee: Kloeckner Ferromatik Desma GmbH
Current assignee: Kloeckner Ferromatik Desma GmbH
Priority date: 1991-07-25
Filing date: 1992-06-05
Publication date: 1993-01-27
Anticipated expiration: 2012-06-05
Also published as: ITMI921177A1; DE4124599C1; GB9211965D0; GB2257924B; DK94492D0; ITMI921177A0; IT1262008B; FR2679483B1; DK94492A; FR2679483A1

Description

2237924 1 Mixincr Head The present invention relates to a mixing head of

the type wherein mixing chamber is connected by way of control valves to supply lines for plastics, dye components and/or the like.

In known mixing chambers of the type described above the supply lines comprise openings or nozzles which lead directly into the mixing chamber and which are connected by way of control valves to associated conveying apparatus. The greater the number of components to be supplied, the more difficult it is to distribute the supply lines on the outside of the chamber, in particular since the chamber dimensions have to be kept as compact as possible. This results on the one hand in the number of component supply lines which may be connected being limited and, in the case of a relatively large number of components to be connected, in considerable constructional expense. Furthermore, difficulties arise from a control point of view and hindrances in the event of repair.

The object of the invention is to carry out the infeed of plastics and/or dye components such that there is no accumulation of supply lines at the outer walls of the mixing chamber. A further object of the invention consists in selecting the respectively desired combination from practically any number of components in a particularly simple manner and supplying it to the mixing chamber.

According to the present invention, there is 2 provided a mixing head having a mixing chambersupply lines for materials to be mixed in the chamber, and control valves for controlling the supply of materials to the mixing chamber, wherein at least one guide groove opening into the mixing chamber is provided in a wall of the mixing chamber, and at least one rail carrying the control valves is displaceable in said at least one guide groove, the control valves having supply openings arranged at a side of the or the respective rail which faces the mixing chamber whereby the rail(s) can be selectively displaced in the groove(s) to bring selected valve opening(s) into communication with the mixing chamber.

Preferably, the control valves are spaced apart on the rail(s) in the direction of sliding movement of the rail(s) relative to the groove(s).

The control valves may engage by means of forward regions thereof in correspondingly constructed bores of the rail(s), and the supply openings of the valves are flush with the peripheral surface of the or the respective rail.

In a preferred embodiment, two guide grooves are provided, which are connected to the mixing chamber at diametrically opposed regions thereof.

Side walls of the rail(s) may be provided with attachment pieces or cutouts which engage in complementary cutouts or attachment pieces in side walls of the guide groove(s). In particular, the side walls of the rail(s) are outwardly curved and the guide groove(s) in a complementary manner thereto islare inwardly curved.

One or more drives may be provided for displacing the rail(s). Such drive(s) may be connected to a program 3 control.

The rail can be guided tangentially with respect to the inner wall of the mixing chamber. However, the underside of the rail can also run in the form of a chord through the mixing chamber during the infeed procedure. Any mixing screw provided can in this case be constructed or even be withdrawn completely out of the chamber such that the displacement of the rail and the supply of the plastics components is not obstructed by the mixing screw.

In particular if the rail bears valves for dye components, the openings of the valves can be located so close to one another that a plurality of components can be introduced into the mixing chamber from one and the same rail.

The present invention has the advantage that the supply of plastics components is restricted without limiting the geometrical factors in the region surrounding the mixing chamber wall. The control of the programs is variable as desired, by combining the valves and supply lines with one of the rails. The plastics is supplied by way of the rails at low constructional expense by making grooves in the chamber wall. In this case, the grooves can be made and the rails can be produced so exactly that no impairment or loss of pressure in the supply of plastics components can occur.

An embodiment of the present invention is illustrated in the accompanying drawings in which:- Fig. 1 is a front view of a mixing head according to an example embodiment of the invention, and Fig. 2 is a sectional view on the line II-II of Fig. 1.

4 Referring to the drawings, a wall 2 of a mixing chamber 1 is provided with two grooves 3 and 31 running perpendicularly with respect to the axis of the mixing chamber. Rails 4 and 41 are displaceably mounted in the respective grooves 3 and 31. Here, the rails 4 and 41 have valves W, W, V etc. which, located next to one another in the manner of a magazine, have the lower regions engaging in cutouts of the rails 4 and 41. Here, openings V6 of the valves open into the mixing chamber 1 when the rails are moved into the appropriate position relative to a region of the mixing chamber which opens onto each respective groove 3 and 31 such that the associated valve openings are flush with the opening of the mixing chamber which runs in the tangential region of the mixing chamber wall containing the rail lower base.

The undersides of the rails having the valve openings V6 can of course also project into the mixing chamber 1 if there is sufficient space between the mixing screw M and the inner wall of the mixing chamber or if the mixing screw is withdrawn out of the mixing chamber.

As can be seen in Figure 1, in the embodiment illustrated, in addition to the valves W, w, V#,"" mounted in the manner of a magazine in the rails, valves V1 and V2 of conventional construction can also engage through the chamber wall 2, these valves V1 and V2 being arranged such that they are offset at two locations offset by 900 with respect to the valve openings on the rails. In addition to the possibility of feeding two basic components by way of the valves V1 and V2, a third or fourth further component, for example also a dye component, can be supplied by way of the rails, as a result of which the program is conducted in a flexible manner and with almost any number of combination possibilities.

The shape and dimension of the groove and of the rail can be seen in Figure 2. These dimensions are predetermined first and foremost by the lower regions of the valves which are mounted in the rail for controlling the supply of plastics components and/or of dyes. In Figure 2, corresponding parts are provided with the reference numerals used in Figure 1. The convexly curved side walls of the rails 4, 41 engage in complementary inwardly curved walls of the guide grooves. A tongue-andgroove system could be used instead of such a construction.

6

Claims

Claims

A mixing head having a mixing chamber, supply lines for materials to be mixed in the chamber and control valves for controlling the supply of materials to the mixing chamber, wherein at least one guide groove opening into the mixing chamber is provided in a wall of the mixing chamber, and at least one rail carrying the control valves is displaceable in said at least one guide groove, the control valves having supply openings arranged at a side of the or the respective rails which faces the mixing chamber whereby the rail(s) can be selectively displaced in the groove(s) to bring selected valve opening(s) into communication with the mixing chamber.
2. A mixing head as claimed in Claim 1, wherein the control valves are spaced apart on the rail(s) in the direction of sliding movement of the rail(s) relative to the groove(s).
3. A mixing head according to Claim 1 or 2, wherein the control valves engage by means of forward region regions thereof in correspondingly constructed bores of the rail(s), and the supply openings of the valves are flush with the peripheral surface of the or the respective rail.
4. A mixing head according to any preceding claim, wherein two guide grooves are provided which are connected to the mixing chamber at diametrically opposed regions thereof.
5. A mixing head according to any preceding claim, wherein side walls of the rail(s) are provided with attachment pieces or cutouts which engage in j 7 complementary cutouts or attachment pieces in side walls of the guide groove(s).
6. A mixing head according to Claim 5, wherein the side walls of the rail(s) are outwardly curved and the guide groove(s) in a complementary manner thereto is/are inwardly curved.
7. A mixing head according to one of the preceding claims, wherein one or more drives are provided for displacing the rail(s).
8. A mixing head according to Claim 7, wherein the drive(s) is/are connected to a program control.