Foldable rail for electric opening-closing curtain

A foldable rail for an electric opening-closing curtain, wherein the foldable rail comprises:

• a first rail, provided with opposed first end and second end;
• the first end is connected to a primary transmission box, and a first joint is sleeved on the second end;
• a second rail, provided with opposed third end and fourth end;
• the third end is connected to a secondary transmission box, and a second joint is sleeved on the fourth end;
• a connection piece, which is connected to the first joint and the second joint;
• the first joint and the second joint can rotate relative to the connection piece;
• a transmission component, one end of which is connected in a winding way to the primary transmission box and the other end is connected in a winding way to the secondary transmission box;
• the transmission component runs through the first rail, the first joint, the second joint and the second rail in sequence along a direction from the primary transmission box to the secondary transmission box, wherein
• two groups of thread columns which are first thread columns and second thread columns are symmetrically disposed at both sides of the connection piece;
• the first thread columns are connected to the first joint and the second thread columns are connected to the second joint,
• a first connection groove connected to the second end of the first rail in a sleeved way is disposed at an end of the first joint, and the other end of the first joint extends to form two symmetrical first connection arms;
• a first thread hole cooperating with the corresponding first thread column is disposed on the first connection arms respectively;
• a second connection groove connected to the fourth end of the second rail in a sleeved way is disposed on one end of the second joint, and the other end of the second joint extends to form two symmetrical second connection arms, each of which is provided with a second thread hole cooperating with the corresponding second thread column, and
• a 90° gear angle is disposed on an upper end of the first connection arms and a 90° right angle is disposed on a lower end of the first connection arms;
• a 90° gear angle is disposed on an upper end of the second connection arms and a 90° right angle is disposed on a lower end of the second connection arms;
• the gear angle on the first connection arms is meshed correspondingly with the gear angle on the second connection arms;
• a center of circle of the gear angle on the first connection arms is overlapped with a center of circle of the corresponding first thread holes, and a center of circle of the gear angle on the second connection arms is overlapped with a center of circle of the corresponding second thread holes;
• when the first rail and the second rail are unfolded to be in one straight line, the right angle on the first connection arms is abutted against the right angle on the corresponding second connection arms;
• when the first rail and the second rail are folded to be in parallel, a distance between the right angle on the first connection arms and the right angle on the corresponding second connection arms is the largest;
• when the first rail and the second rail are folded up from the unfolded state, the gear angle on the first connection arms is always meshed with the gear angle on the corresponding second connection arms.