Apparatus for tensioning torsion spring, shaft-mounted in association with a spring cone, has a central ratchet assembly with two spaced, cogged ratchet wheels, slotted to allow the assembly to be rotatably positioned over the shaft. The ratchet assembly is connectable to the spring cone so that the spring cone will rotate with the ratchet assembly. The ratchet wheel slots are closed off by cogged bridging elements that create a continuous cogged perimeter around each ratchet wheel. Pawl-equipped levers are positioned over the ratchet wheels with the pawls engageably aligned with the ratchet wheel cogs, and then operated in alternating fashion to rotate the ratchet assembly and spring cone, thus tensioning the spring. Upon achieving a desired spring tension, the spring cone may be secured to the shaft, whereupon the bridging elements may be retracted from the ratchet wheel slots to permit removal of the apparatus from the shaft.