Screwing/unscrewing tool suitable for a screw or a bolt that is difficult to access, in particular on a mast or a jib of a crane

A screwing/unscrewing system for screwing/unscrewing a screw or a bolt, the screwing/unscrewing system comprising:

• a screwing/unscrewing tool comprising
• a first part and a second part coupled in rotation around a main axis, and comprising an adjustment screw, and wherein
• the first part comprises a lever secured to a screwing/unscrewing bit provided with at least one screwing/unscrewing recess centered on the main axis;
• the second part comprises a support arm on which the screwing/unscrewing bit is rotatably mounted around the main axis, said support arm being equipped with a tapped hole;
• and
• the adjustment screw is screwed into the tapped hole, the adjustment screw having a coupling head configured for a coupling with a screw-gun or a wrench, and extended by a threaded rod having a free end suitable for abutment on the lever of the first part in order to apply a pivoting force to the lever around the main axis, and wherein the tapped hole and the adjustment screw are centered on a screwing axis contained in a plane orthogonal to the main axis;
• and
• the wrench or the screw-gun provided with a bit configured for cooperating with the coupling head of the adjustment screw, in order to be able to screw the adjustment screw into the tapped hole and thus moving the adjustment screw in translation to push the lever and thus rotate the screwing/unscrewing bit.

A screwing/unscrewing method for screwing or unscrewing a screw or a bolt with a screwing/unscrewing tool comprising a first part and a second part coupled in rotation around a main axis, and comprising an adjustment screw, and wherein the first part comprises a lever secured to a screwing/unscrewing bit provided with at least one screwing/unscrewing recess centered on the main axis, the second part comprises a support arm on which the screwing/unscrewing bit is rotatably mounted around the main axis, said support arm being equipped with a tapped hole, and the adjustment screw is screwed into the tapped hole, the adjustment screw having a coupling head configured for a coupling with a screw-gun or a wrench, and extended by a threaded rod having a free end suitable for abutment on the lever of the first part in order to apply a pivoting force to the lever around the main axis, and wherein the tapped hole and the adjustment screw are centered on a screwing axis contained in a plane orthogonal to the main axis, the screwing/unscrewing method comprising:

• placing the screwing/unscrewing bit on the screw or the bolt;
• coupling the coupling head of the adjustment screw to a bit of a screw-gun or to a wrench;
• and
• operating the screw-gun or rotate the wrench to screw the adjustment screw into the tapped hole and thus move the adjustment screw in translation to push the lever and thus rotate the screwing/unscrewing bit in the direction of screwing or unscrewing the screw or the bolt.