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:
Sep. 02, 1980
Filed:
Jan. 22, 1979
Johan G Johansson, Taby, SE;
Defibrator Aktiebolag, Stockholm, SE;
Abstract
Grinding apparatus in which lignocellulosic material such as wood chips is ground between a pair of grinding discs which rotate relatively to one another within a housing into which the material is advanced through a feed-in opening by means of a feed screw which rotates in a concentric sleeve extending between the central feed-in opening and an intake opening for the material. The feed screw comprises a series of inner screw flights mounted on a central shaft, which screw flights support and are enveloped by a series of outer ribbon-like screw flights. The inner screw flights are designed primarily to propel the material radially outwards towards the wall of the surrounding sleeve, whereas the outer ribbon-like screw flights are designed primarily to advance the material in an axial direction towards the central feed-in opening.