Head brake release with memory and method of controlling a drill head
US5927408A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | May 22, 2017 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B19/20
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A control is provided for a drill head that is mounted on a drill mast. Hydraulic motors raise and lower the drill head and a hydraulically releasable brake holds the drill head in position on the mast. The control has a hoist line that connects the hydraulic motors to a source of hydraulic fluid under pressure. A brake release line is connected to the brake and a brake release valve normally connects the brake release to a tank. The brake release valve is electrically actuated to connect the brake release line to a source of hydraulic fluid under pressure to release the brake. A programmable logic controller with a memory storage controls the actuation of the brake release valve. A pressure transducer is connected to the hoist line and to the controller for providing a signal to the controller representative of the hoist line pressure and this signal is storable in the memory. The controller will actuate the brake release valve only after the hoist line pressure sensed by the transducer is as great as the pressure stored in memory. The control also includes a brake switch connected to the controller and actuated to set and release the brake. A timer in the controller is turned on …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.