Injection appts. for mfg. lost wax patterns for precision casting - where injection cylinder is automatically replenished with molten wax during each moulding cycle

摘要

Molten wax in a heated tank is pumped into a first cylinder contg. a tubular piston (I), via which the wax travels into a second cylinder. The wax is then driven out of the second cylinder and into a die via a piston (II). During and/or after the filling of the die to make a pattern, fresh wax enters the second cylinder near the working surface of the piston (II). In the pref. plant, the piston rod on the piston (I) is a tube contg. wax outlet holes adjacent to the surface of piston (II) and the rodis fixed to piston (II). The second cylinder has a vol. much larger than the pattern cavity in the die. When fresh wax enters the second cylinder it creates turbulence, so that any fillers which have sepd. out of the wax already in the second cylinder are re-mixed with the wax.