US 4,364,270 AGranted

Device for pneumatically scanning the level of liquid in a container

AssigneeSiemens Aktiengesellschaft

InventorsAlfred Heinzl, Heinz Stadler

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Abstract

A device for pneumatically scanning the level of liquid in a container, such as small housings for electronic components which are to be filled with casting resin, has a pneumatic scanning nozzle disposed above the component housing for directing an extremely low pressure air stream at the liquid surface in the housing. The nozzle has a branch conduit leading to a piston movable to actuate a proximity switch for providing a signal to cease the supply of liquid to the container. When a pre-determined liquid level is attained in the container, the back pressure through the conduit moves the piston against a spring bias to actuate the proximity switch. The liquid level is thus determined in a contact-free manner so that the measuring system remains untouched by the casting resin.

Claims7

Dependent claims

A device for scanning the level of liquid in a container comprising:

a scanning nozzle connected to a compressed air supply, said nozzle disposed above said container for directing air at a surface of said liquid in said container;
a housing having an interior chamber;
a piston contained in said chamber in contact-free fashion;
a means for supporting said piston in said chamber and for permitting displacement of said piston in said chamber;
a proximity switch disposed in said chamber a distance from a portion of said piston for emitting a signal when said distance is reduced by a pre-determined amount by displacement of said piston toward said switch;
and
a pressure tube interconnected between said chamber of said housing and said nozzle for directing back pressure to said chamber when said liquid in said container reaches a pre-determined level, whereby said back pressure displaces said piston into contact with said proximity switch for actuation thereof.

4 more elements

Dependencies are inferred from the claim text.