Threaded joint making apparatus having a d.c. power supply
US4208919A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 12, 1978 |
| Grant date | Jun 24, 1980 |
| Priority date | — |
| Expiry date | Sep 12, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L5/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus is provided for making threaded joints, such as pipe joints, including means for storing and indicating values of the actual torque applied to one of the members being rotated with respect to the other member and values of actual turns made by the one member and a d.c. power supply for powering the storage and indicating means. The power supply is connected to a first source of power such as an a.c.-to-d.c. converter for normal operation. The power supply generates a predetermined magnitude voltage and has means responsive to the predetermined magnitude value for switching to a second source of power, such as a battery, when the first source of power fails. The power supply also includes a d.c.-to-d.c. inverter having transistor switching means connected between a transformer and a power source. The transistor switching means are switched on and off to induce current flow in the transformer secondary to generate the power to the storage and indicating means. A transistor is connected to be responsive to the turning off of the transistor switching means for rapidly discharging a stored base charge to increase the efficiency of the power supply.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.