Manual pipe tong having secondary safety latch
US6119558A · kind A · utility
Inventor
Key dates
| Filing date | Apr 21, 1999 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Apr 21, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B13/52
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Manual pipe tong comprising secondary latch. The pipe tong comprises a handle and a plurality of linked jaw segments pivotally attached to the handle. Two of the segments are first and second latch segments, and are releasably engageable to form a primary latch. The primary latch may be released and the jaw segments opened to encircle a tubular for makeup of a threaded connection. The first latch segment comprises substantially parallel upper and lower surfaces, and projections on each of those surfaces. A hooking member on the second latch segment comprises a pair of spaced-apart hooks joined by a handle, and is rotably disposed on the second latch segment so that the hooks sandwich the second latch segment. The hooking member is rotatable between first and second positions, and in the second position the hooks engage the projections on the first latch segment so as to form a secondary safety latch. In the event of a tong jaw segment failure, the secondary safety latch keeps the jaw segment fragments linked to the unbroken jaw segments, preventing projectiles from being formed by the fragments. The secondary safety latch also prevents unintentional unlatching of the primary latch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.