Reinforcement tensioner for concrete pipe mfr. - has frame moving lengthwise of pipe and carrying hydraulically operated tensioning wheel carrying wire loop

摘要

The tension device includes a frame movable lengthwise of the pipe, the frame having a shaft parallel to the pipe on which is rotatably mounted a bull wheel around which a single turn of the wire rod is wrapped. An hydraulic pump is supported on a torque frame which in turn is rotatably supported on the shaft. The pump is driven in response to rotation of the bull wheel. A load-sensing element is mounted on the frame and engages the torque frame at a radial distance from the axis of the shaft that is substantially equal to the radius of the bull wheel. The hydraulic load on the pump controls the torque load on the bull wheel and hence the tension in the rod as it is withdrawn tangentially from the bull wheel.