Abstract: A component-feed nozzle for a reaction-mixing head of a reaction injection device includes a housing having a component inlet and a component outlet. Received in the housing is a closing and flow restriction member which is movable by a linear drive between at least two positions. In a first position, the closing and flow restriction member closes the component outlet, and in a second position clears the component outlet, thereby establishing a flow communication between the component inlet and the component outlet. The closing and flow restriction member has at least a first area and a second area, which generate forces in opposite directions, when the component pressure is applied, wherein the areas are sized in such a way that the opposing forces substantially offset one another.

Abstract: The present invention relates to a mould, in which a completely closed cavity can be formed in one operating state, comprising an injector (10) which is at least partially accommodated in the mould (14) and the discharge opening of which opens into the closed cavity. According to the invention, the injector is designed with a material feed duct (30) and a material return duct (34), wherein the two ducts (30, 34) open into a connecting chamber (32) in the region of the tip of the injector (10) and are flow-connected to one another via said connecting chamber (32). In this case, an injector needle (36) can be switched into at least two operating positions, wherein, in one moved-forward operating position, the discharge opening is closed by means of the tip (38) of the injector needle (36) and, in the other, pulled-back operating position, the discharge opening is flow-connected to the connecting chamber, and the injector (10) is therefore open.