The part where the conduit is connected to the junction box is called the lock nut. The lock nut is used to fasten the electrical tubes that pass through the wire box inside the box. If the lock nut is not used, it will be ugly when the wire tube is inserted, and the mouth of the tube will easily scratch the wires. A wire is composed of one or several soft conductors covered with a light and soft sheath; a cable is composed of one or several insulated conductors covered with a tough outer layer made of metal or rubber.
Extended information:
A 90-degree bend can be made from the rear of the lock nut to reach the axis. However, the bending radius of this bend plus the thickness of the junction box far exceeds the distance from the wall to the axis. distance, causing the junction box to protrude too much from the wall. If the junction box is moderately protruding from the wall, the conduit will deviate far from the axis, which will have a huge impact on the wall building work and affect the structure, which is not feasible.
With traditional construction techniques, bending pipes and fixing junction boxes is extremely difficult: the next process of threading is also quite laborious. When applying the present invention, the end of the conduit is bent into an obtuse angle. At this time, the distance between the conduit at the axis position and the rear of the junction box is the shortest, so the wedge-shaped straight connection can be quickly and conveniently connected.
Thus, when the conduit is pre-embedded at the axis position, the junction box can be appropriately protruded from the wall, and there will be no problem of leaving too large a hole. The patented junction box is used on concrete walls and pillars, and is closer to the box formwork (wall skin) than traditional junction boxes. It is easier to find the junction box after removing the formwork, eliminating the need to fill in half a junction box, and making installation easier.
Baidu Encyclopedia-Junction Box