Moling system including transmitter-carrying mole for detecting and displaying the roll angle of the mole
US5182516A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1991 |
| Grant date | Jan 26, 1993 |
| Priority date | — |
| Expiry date | Jan 23, 2011 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/13
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A moling system comprises a mole (10) having a head (26) with a slant face at the leading end of a string of hollow rods (20). The rods are rotatable by a rig (12). The mole is an impact mole fed by air passed through the rods. While the mole rotates it travels approximately straight, but nonrotating it travels according to the direction of the slant face (28). The mole contains a radio sonde having one coil lying lengthwise and one transverse to the lengthwise direction of the mole. A receiver (22) is traversed across the ground to locate the radio sonde and display roll angle. The mole is stopped from rotating at the correct position when steering is required and powered without rotating to change course. An impact activated switch in the mole switches off the battery supply while the impact mechanism is activated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.