The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 26, 1988
Filed:
Dec. 22, 1986
Finn Kroksnes, Hamburg, DE;
Abstract
In operation of a screw extruder, particularly a pin extruder, processing a rubber or a plastic mixture, troubling disturbances and on occasion heavy damage occur when foreign bodies are introduced into the extruder with the material to be processed causing damage to the extruder structure. In order to avoid this damage one possibility is to shut off the extruder at a sufficiently early time and of course immediately when an appropriate dangerous condition is detected. Therefore the drive torque which is taken by the extruder screw shaft is compared with the mass pressure in the mixture to be processed. As soon as this compared value no longer follows the functional dependence of the normal operating parameters such as the rotation speed of the extruder shaft, viscosity of the mixture, temperature lowering of the tempering medium, the volume increase of the mixture drawn in the extruder inlet or the like, the extruder is automatically shut off since a disturbance by foreign bodies is assumed. For determination of the torque a torque measuring shaft is used or a measured quantity proportional to it referred to. The mass pressure can be measured in the material to be processed by a mass pressure sensor in a pin of a pin cylinder in the extruder.