Preheating and dosing apparatus
CA 1311340 C · Owner: Plastronica Ag · Inventors: Zahradnik, Rudolf
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An apparatus for preheating and dosing plastic which is to be fed to an extruder consists of a housing 3 with a heatable casing and a double worm screw (1,2) mounted at both ends in the housing 3 and turning oppositely. The two worm screws (1,2) of the double worm screw are hollow, such that the hollow cavity (8) serves to accept a heating medium, for example hot water, for the purpose of heating the worm screws (1,2). The apparatus allows the working material to be uniformly heated, and precisely metered to the extruder. (Fig. 2).
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted December 15, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended December 15, 2009.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.