Issued Patents All Time
Showing 1–20 of 20 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 11034073 | Method for forming inline triple wall coupling connector | Stefan A. Lupke | 2021-06-15 |
| 7691317 | Method and device for manufacturing a double-walled, thermoplastic tube with a connecting sleeve | Stefan A. Lupke | 2010-04-06 |
| 7214051 | Device for manufacturing a double-walled thermoplastic pipe with a connecting sleeve | Stefan A. Lupke | 2007-05-08 |
| 6401320 | Method of simultaneously making a plurality of metallic pipes | Stefan A. Lupke | 2002-06-11 |
| 5846575 | Pipe forming mandrel with multiple sleeve inner tube | Stefan A. Lupke | 1998-12-08 |
| 5803132 | Skinned double wall pipe and apparatus for making same | — | 1998-09-08 |
| 5545369 | Clamshell corrugators and the like | — | 1996-08-13 |
| 5542834 | Skinned double wall pipe and apparatus for making same | — | 1996-08-06 |
| 5516482 | Travelling mold tunnel apparatus for smooth walled pipe | — | 1996-05-14 |
| 5466402 | Gap adjustment of a plastic flow channel in a plastic part forming device | — | 1995-11-14 |
| 5383998 | Apparatus for modifying corrugated or ribbed pipe to have a smooth outer wall | — | 1995-01-24 |
| 5330600 | Method of modifying corrugated or ribbed pipe to have a smooth outer wall | — | 1994-07-19 |
| 5296188 | Methods for forming tubing utilizing suction and pneumatic pressure at the surface of the cooling plug | — | 1994-03-22 |
| 5186878 | Improvements relating to cooling plugs in thermoplastic pipe forming apparatus and process | — | 1993-02-16 |
| 4731138 | Apparatus for producing double-walled corrugated pipes | — | 1988-03-15 |
| 4689174 | Producing double-walled helically wound thermoplastic pipe with a corrugated cutter wall and a smooth inner wall | — | 1987-08-25 |
| 4555230 | Calibrator for use in the manufacture of double walled thermoplastic pipe | — | 1985-11-26 |
| 4521270 | Apparatus for forming spirally wound pipe | — | 1985-06-04 |
| 4500284 | Forming single wall bells in double wall pipe | — | 1985-02-19 |
| 4292014 | Feed mechanism comprising an endless member configured as a double helix | Gerd P. H. Lupke | 1981-09-29 |