Valve assembly for venting diecasting moulds

#1. Field of the Invention

#The present invention refers to a valve assembly for venting diecasting moulds. The valve assembly comprises a venting channel, a venting valve communicating with the venting channel and having an axially displaceable valve closure member, and an actuating member for operating the venting valve from an open position into a closed position.

#The actuating member includes a power pick up member exposed to the liquid casting material escaping during the casting operation from a casting chamber provided in the diecasting mould through the venting channel and being axially displaceable under the influence of the kinetic energy transmitted from the liquid casting material to the power pick up member when the liquid casting material hits the power pick up member. The power pick up member is mechanically coupled to the axially displaceable valve closure member and it includes an axially displaceable push member.

#In the following, some embodiments of the valve assembly according to the invention will be further described, with reference to the accompanying drawings, in which:

#FIG. 1 shows a longitudinal sectional view of a first embodiment of a valve assembly, mounted to the one mould portion of a two-part mould which is shown in its open position;

#FIG. 2 shows a front view of a first portion of the housing block of the valve assembly according to FIG. 1;

#The valve assembly 1 shown in the FIGS. 1 to 6 is contained in a rectangular parallelepiped-shaped two-part housing block comprising a back housing block portion 2 and a front housing block portion 3 having a plane front surface 5. In other words, the housing block of the valve assembly 1 is divided along a separating plane 4 into the two portions 2 and 3. The housing block 2, 3 is received in a recess provided in a mould portion 6 of a two-part mould consisting of the two mould portions 6 and 7 adapted to be pressed one against the other one, as is well known in the art. The position of the valve assembly 1 is at the outer border of the contacting surface 8 of the mould portion 6. The mould portions 6 and 7 are but partially shown in the drawings. The front surface 5 of the housing block 2, 3 flushes with the contacting surface 8 of the mould portion 6 such that the front surface 5 as well as the contacting surface 8 sealingly engages the contacting surface 9 of the other mould portion 7 once the mould 6, 7 has been closed.

#The housing block 2, 3 may be fixed to the mould portion 6 by means of screw means not shown in the drawing. Similarly, the housing block portions 2 and 3 can be fixed to each other by screw means which also are not shown in the drawing.

#The housing block portion 3 is provided with a venting channel generally designated with reference numeral 10; thereby, the venting channel 10 is open towards the front surface 5 of the housing block portion 3. This venting channel 10 of the valve assembly 1 will be described in detail in connection with FIG. 4 hereinafter. The venting channel 10 communicating with the casting chamber of the mould constitutes a continuation of a venting channel 11 provided in the mould portion 6 and being open towards the contacting surface 8 as well.