Georg Fischer Aktiengesellschaft

George Fischer Limited

Georg Fischer Aktiengeselleschaft

Hans Tanner

Kurt Fischer

Gerhard Baumann

Xaver Wuchner

Robert Steinemann

An apparatus for the introduction of a gaseous medium into a chamber, especially for compressing casting molding material with a high-pressure gaseous medium supplied by a pressure vessel linked with the chamber by means of a valve system. The system has a seat having traversing openings which can be covered or uncovered by a stroke-activatable valve plate. The gaseous medium flows freely round the surface of the valve plate. The valve plate also is provided with traversing openings which, however, are displaceably arranged vis-a-vis the traversing openings of the valve seat. To trigger a pressure shock from the gaseous medium necessary to effect compression, an elevating mechanism for the valve is activated to lift the valve plate. The pressurized gaseous medium then flows round, as also throughout the valve plate and acts on the surface of the chamber.

Apparatus for the compression of granular material

The apparatus has a plurality of tubular hollow members arranged between the pressure chamber and the molding units, in the pressure surge flow direction, for conducting the gaseous medium to the top of the molding material. With distribution of the pressure medium flow through a plurality of independent and different cross sections, the lifting force required to open the packing element is greatly reduced and the packing element can be opened rapidly.

Apparatus for compacting granular molding materials by pressurized

Loosely poured granular material is compacted by a burst of air under pressure which is built up in a space Q1 and is abruptly released through the outlet end of a passageway Q3 which opens toward the material surface. While the pressure in Q1 is being built up and until released, it is restrained by a sealing member which concurrently covers the outlet side of Q1, the input end of passage Q3 and an accelerating space Q2. The sealing member is held in place by a counterpressure in a space Q4 acting on a larger surface area than Q1. The pressure is suddenly decreased in Q4, abruptly unbalancing the pressures and releasing the pressurized gas from Q1 into Q3 and against the surface.

Method and apparatus for compacting granular moulding materials

In a closed system a shock pressure wave of a burning gas is used for packing granular mold material loosely distributed around a model. Before the shock pressure is produced, the pore volume of the upper layer of the granular material exposed to the pressure is reduced. Through the pore volume reduction, the active surface of the granular material is increased, so that the gas pressure acts on an increased working surface and, consequently, greater mold hardness is achieved.

Process and apparatus for packing granular foundry materials

A method of compacting particulate material includes providing a primary fuel mixture of air and natural gas in a closed chamber enclosing a surface of the material to be compacted. An additive gas, such as hydrogen, having a higher combustion velocity is added to the primary fuel/air mix and ignited, creating an exothermic reaction which compacts the material. The additive gas increases the gradient of the pressure rise curve of the combustion. Various fuels and additive gases and disclosed.

Process for compacting granular materials

For packing granular materials, especially foundry moulding materials, by means of an exothermic reaction of a mixture of air and fuel in a combustion chamber (23), a relative movement between the combustible mixture and one or several pulse triggers (19), is produced during the exothermic reaction, preferably by a blower (20) disposed in the combustion chamber (23). Hence the measured amount of sand introduced into a moulding frame (11) and a filling frame (12) over a pattern (6) by means of a sand container (17) is packed to form a mould body.

Method and apparatus for packing granular materials

A die head has replaceable radially slidable threading dies moved by a bushing with cams. As the workpiece is threaded to the desired length, its end contacts cam surfaces which move a sensor bolt and a control pin to disengage the bushing from a locked position. The bushing can then move axially to radially retract the threading dies from the workpiece.

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Schaffhausen, Switzerland

Hans Tanner