Test plug for waste pipe
US5307841A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 14, 1993 |
| Grant date | May 3, 1994 |
| Priority date | — |
| Expiry date | Apr 14, 2013 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16L55/132
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A test plug for sealing a waste pipe includes a generally cylindrical piston having an inwardly tapered lower end with a maximum outer diameter slightly smaller than an inner diameter of a waste pipe. A threaded rod has a segment that extends through the unthreaded central bore of a cylindrical holder and has a lower end connected to the piston. A knob is screwed over the upper end of the rod. An elastomeric O-ring surrounds the tapered lower end of the piston and is deformable in a radially outward direction into sealing engagement with an inner wall of the waste pipe by expanding the O-ring over the tapered lower end of the piston. The knob is turned to pull the rod upwardly through the holder. This causes the lower end of the holder to push the O-ring downwardly over the tapered lower end of the piston, thereby expanding the O-ring against the inner wall of the pipe. A plurality of gripping teeth are pivotally mounted in slots formed at circumferentially spaced locations about the cylindrical holder. Cams on the inner ends of the teeth engage a complementary shaped receptacle in an outer wall of the piston for pivoting the teeth to engage the inner wall of the waste pipe. The kn…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.