| 摘要 |
Discrete bars are formed into a spiral component for a baluster by disposing a plurality of the bars side by side. A rod is butt welded to one of the two ends of the plurality of bars. Then the bars are cold twisted axially a first angular amount in one direction by applying twisting torque along the bars, without twisting the rod welded to the bars. The bars are also cold twisted in the opposite direction a second angular amount less than the first angular amount, while axially compressing the bars to form a spiral. The twisting can be done with a machine having a spaced pair of holding devices mounted on a frame. These holding devices can hold therebetween a number of the bars side by side and in abutting alignment with one of the rods. At least one of the holding devices has a holder for holding and preventing twisting of one of the rods. One of the holding devices can twist the bars while the other acts as a slider mounted on a pair of rails to be driven by a linear ram. For synchronously forming groupings of discrete bars into spiral components, a common drive motor can turn at least one of said holding devices at each of the frames. Then the bars in each of the groupings can be cold twisted synchronously and axially in one direction then the other, while axially compressing the bars to form a spiral.
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