Apparatus 100 for maintaining tension in a shaft of a structure, the apparatus comprising a shaft 10 comprising a plurality of shaft indentations 15, a reaction block 20 configured to be positioned around the shaft and constrained laterally relative to the shaft, and at least one locking collar 30 comprising at least one proximal engaging surface 34 configured to engage restraining surfaces 17 of the shaft, and a distal engaging surface 32 configured to engage a shoulder surface 22 of the reaction block. The locking collar is biased radially inwards towards the shaft to form a ratchet by virtue of the engagement between the locking collar and the shaft indentations. A ratchet device for maintaining tension in a shaft of a structure is disclosed, as is a de-tensioning tool (550, Fig 5a) that incorporates first and second linear actuators (560, 570, Fig 5a) and methods of using the apparatus, ratchet device and de-tensioning tool.
Tensioning apparatus
2025-05-28
Patent
Electronic Resource
English