Plastic Industry Today

The invention relates to a device forspraying-on of especially plastic Mould, wherein at least one mould cavity to be filled, constructed in a tool is arranged laterally next to a central nozzle body, with at least one nozzle tip arranged in and/or on the nozzle body which projectsoutwards over the circumferential surface of the nozzle body and forms an injection channel for the mould cavity in a recess of the tool and/or the nozzle body, according to the preamble of claim 1.

In known devices of this type, the nozzle tips are fixed in the nozzle body before assembling the tool, generally screwed in. In order to then make it possible to assemble the tool, the tool, that is, the element in which the mould cavities to befilled are arranged, must be segmented and dismountable according to the number of nozzles and mould cavities. This requires, on the one hand, a comparatively high constructive effort and on the other hand, the assembly of the tool is complex andtime-consuming and thereby incurs high costs.

Starting from this prior art, it is the object of the present invention to provide a generic device which has a simple structure and is mountable and dismountable in a simple and cheap fashion.

This object is solved by a device according to the teaching of claim 1.

Advantageous embodiments of the invention are the subject matter of the dependent claims.

The device according to the invention for spraying-on of especially plastic Mould has, in an initially inherently known fashion, at least one mould cavity to be filled, constructed in a tool which is arranged laterally next to a centralnozzle body, and at least one nozzle tip arranged in and/or on the nozzle body which projects outwards over the circumferential surface of the nozzle body and forms an injection channel for the mould cavity in a recess of the tool and/or the nozzle body.

According to the invention, there is at least one further recess arranged in the area of the bottom of the nozzle body, wherein this recess is provided with at least one through opening which connects the recess to the circumferential surface ofthe nozzle body and wherein the nozzle tip can be inserted through the recess into the opening and can be detachably affixed there. As a result of this structure, during assembly of the tool the nozzle body can initially be inserted into thecorresponding recess of the tool in a more or less form-locking manner without especially projecting nozzle tips, after which the nozzle tips are only then mounted by engagement in the respective mould cavities or the corresponding feed channels. Thus,segmenting of the tool is no longer necessary.

In a fundamentally arbitrary manner an arrangement with only one mould cavity is feasible. Preferably however, a plurality of nozzle tips is provided and the recess is provided with a number of openings correspond to the number of nozzle tips.

The arrangement of the mould cavities in the tool and thus correspondingly the arrangement of the nozzle tips in the nozzle body is arbitrary. According to one exemplary embodiment however, the nozzle tips are arranged in the nozzle body atleast in groups in a row and/or in the fashion of a triangle, square or a polygon shape. In this case, the arrangement can take place not only in a plane but also spatially offset.

According to a further exemplary embodiment, the nozzle body has at least in sections, a substantially cylindrical shape wherein the openings are arranged such that the nozzle tips project in a substantially star shape in the radial directionfrom the nozzle body. With such an arrangement, a simple, substantially rotationally symmetrical structure of the device is obtained.

The shape of the recess in the bottom of the nozzle body is initially fundamentally arbitrary. According to a preferred exemplary embodiment however, the recess has a substantially dish-shaped cylindrical or polygonal cross-sectional shape witha base running perpendicular to the longitudinal axis of the nozzle body and a side wall running substantially perpendicular thereto. In this case, the openings are preferably arranged substantially in the area of the side wall.

The nozzle tips can be fixed in the nozzle body in an arbitrary fashion. According to one exemplary embodiment, for this purpose the nozzle tips have a flange-, collar- or head-like shoulder on their end opposite the tip, wherein the collarsurface of the head-like shoulder of the nozzle tips pointing towards the side wall of the recess is constructed as a stop face, which can be brought to rest supported on the side wall of the recess. As a result, a precisely axially specified positionof the nozzle tips in the nozzle body is obtained.

The nozzle tips and the through openings are preferably provided at least in sections with substantially cylindrical fitting areas such that the nozzle tips can be inserted into the openings at least substantially free from play. As a result, aprecisely radially specified position of the nozzle tips in the nozzle body is obtained. The terms "axial" and "radial" relate to the longitudinal axis of the nozzle tips.

In order to remove the nozzle tips from the nozzle body during dismantling of the tool or for repair purposes or the like, according to one exemplary embodiment the head-like shoulder has an engagement for a tool with which the nozzle tips can bepulled out of the opening. In this case, the engagement can be formed, for example, by an annular-groove-like indentation surrounding the head-like shoulder at least in sections on its radial outer surface or it can be formed by an inner thread formedin the head surface.

According to a further exemplary embodiment, in the recess between the head-like shoulders of the nozzle tips there is detachably arranged a fixing element whose outer surfaces pointing towards the head surfaces of the nozzle tips are constructedas stop faces on the head surfaces such that when the nozzle tips are mounted and the fixing element is mounted, the head surfaces of the nozzle tips come to rest supported on the stop faces. In other words, this means that this fixing element serves asprotection against unintentional loosening of the nozzle tips by sliding out of the respective opening of the nozzle body into the recess.

The shape of this fixing element is fundamentally arbitrary. For example, this can be constructed as ring-shaped, star-shaped or rod-shaped. Preferably however, the fixing element is constructed as a substantially cylindrical or polygonalfixing block in cross-section, which can be detachably affixed by means of a fixing screw at the bottom of the recess.

According to a further embodiment of the fixing of the nozzle tips in the nozzle body, the nozzle tips are provided, at least in sections, with an outer thread and the through openings in the nozzle body are provided, at least in sections, withan inner thread complementary thereto so that the nozzle tips can be screwed into the openings. In this case, the head-like shoulder can be constructed in the fashion of a screw head, especially in the fashion of a hollow screw with hexagonal recess.