Methods for forming inverts in manhold assemblies
US4801417A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1987 |
| Grant date | Jan 31, 1989 |
| Priority date | — |
| Expiry date | May 26, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB28B21/56
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In a method for forming inverts in a manhole base using a two pour technique, the manhole base is initially formed. Thereafter, channel invert forms are aligned with sidewall openings by alignment members arranged within the manhole openings to assure precise alignment therebetween, wherein the invert formed within the manhole base by pouring the casting material into the base member is in precise alignment with associated sidewall openings. The apparatus for the two pour technique incorporates at least one adjustably positionable channel-forming assembly for forming an invert communicating between associated sidewall openings each having a central axis and whose intersecting central axes define an angle different from 180.degree.. In one arrangement, flexible members join the ends of the invert form. Alignment members on the inverts and a flexible internal member, either alone, or in cooperation with a joining bar and clamp, assure precise alignment between the channel-shaped projections forming the invert and prevent flotation of the invert form during casting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.