Patent Number: 6,170,310

Title: Transmission shaft of a movable arm of a pipe bender

Abstract: A transmission shaft of a movable arm of a pipe bender comprises a main shaft, a sun gear ring and a central gear shaft. The main shaft has an upper end fixedly connected to the movable arm, and has several planet gears received therein; the planet gears each communicates with a corresponding one of side openings of the main shaft. The sun gear ring is located around, and engages the planet gears, and is fixed to a fixed arm of the pipe bender. The central gear shaft has an upper end gear portion passed into the main shaft, and engaging the planet gears. A lower end of the central gear shaft is connected to a power source. Thus, the main shaft can turn to move the movable arm when the central gear shaft is turned because the sun gear ring is fixed. The dimensions of the gears do not have to be increased to increase the torque because of the present structure.

Inventors: Wang; Sheng-Tsung (Tainan Hsien, TW)

Assignee:

International Classification: B21D 7/024 (20060101); B21D 7/02 (20060101); B21D 007/04 (); B21D 009/05 ()

Expiration Date: 01/09/2013