Issued Patents All Time
Showing 1–18 of 18 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5860771 | Retaining wall/tie-back/anchor assembly | Gary K. Munkelt | 1999-01-19 |
| 5127770 | Retaining wall assembly utilizing face panels interlocked with tie-back/anchors | Gary K. Munkelt | 1992-07-07 |
| 5114162 | Gasket for use in manhole bases and the like | — | 1992-05-19 |
| 4941643 | Apparatus for forming inverts and manhole assemblies and the like utilizing adjustable invert forming members joined with an intermediate flexible portion | — | 1990-07-17 |
| 4903970 | Apparatus for providing a watertight seal for manhole pipe connections including a foldable gasket and clamping band assembly and expansion means for installing the gasket and clamping band assembly | James A. Westhoff | 1990-02-27 |
| 4801417 | Methods for forming inverts in manhold assemblies | — | 1989-01-31 |
| 4751799 | Method and apparatus for lining manhole assemblies and the like | James R. Westhoff, Eric Ditcher | 1988-06-21 |
| 4737220 | Method of making a manhole riser having integral flexible waterlock for manhole covers and having a water tight seal for sealed manhole covers | Eric Ditcher, James A. Westhoff | 1988-04-12 |
| 4719724 | Precast concrete manhole adjustable bolt slot assembly for securing cast iron frame and cover | — | 1988-01-19 |
| 4711455 | Gasket for use in manholes and including clamping band having cooperating projections and grooves for preventing relative axial movement of the opposing ends of the clamping band during installation and for facilitating expansion by an expansion jack | James A. Westhoff | 1987-12-08 |
| 4685650 | Apparatus for forming inverts and manhole assemblies | — | 1987-08-11 |
| 4621941 | Manhole riser having integral flexible waterlock for manhole covers and having a water tight seal for sealed manhole covers | Eric Ditcher, James A. Westhoff | 1986-11-11 |
| 4618464 | Precast concrete manhole adjustable bolt slot for securing cast iron frame and cover and method for casting same | — | 1986-10-21 |
| 4566483 | Drop manhole precast encasement | — | 1986-01-28 |
| 4565347 | Monolithic precast invert system | — | 1986-01-21 |
| 4540310 | Manhole riser and cooperating sleeve to provide a waterlock for manhole structures | Eric Ditcher | 1985-09-10 |
| 4422994 | Method and apparatus for forming inverts in manhole assemblies, and the like | — | 1983-12-27 |
| 4387900 | Method and apparatus for providing watertight seal for manhole pipe connection | James A. Westhoff | 1983-06-14 |