GB560881A - Improvements in or relating to die casting or injection moulding - Google Patents

Abstract

560,881. Injection-moulding machines. O'SHEI, W. E. Nov. 2, 1942, No. 15393. [Class 87 (ii)] [Also in Group XXII] In the pressure casting of material, the mould has a wall which is free to move under pressure of the material forced in and this movement is resisted by a spring 13 and -so that it will indicate the casting pressure and, if the spring is preloaded, pressure above a desired minimum only. The movable wall may form part of the wall of the mould cavity 3 or, as shown at 8, of a separate chamber 7. The pressure in the mould is thus indicated by the thickness of the test piece formed in the chamber 7 or formed on the casting or by the amount of projection of the stem 9 which may be graduated. A test piece formed on a casting may be subsequently removed or if preferred the movable wall may comprise a pin 11, Fig. 3, projecting into the mould cavity 3 to form a depression, the depth of which indicates the applied pressure. The spring pressure may be arranged so that the pin is forced out flush with the surface 12 when the desired minimum pressure is obtained. The surface 12 may be embossed to show the position of the test piece and indicate the said pressure for which the spring 13 is set. The pin and spring may be embodied in a housing 14 adapted to be screwed into the wall 10 of a mould and an extension 17 of the pin 11 may be calibrated.