| 摘要 |
An apparatus and process for completing the assembly of a joist including a support platform adapted to carry a joist in a generally horizontal orientation with a bottom chord extending along one side and a top chord extending along an opposite side, rollers carried by said support platform each having a plurality of laterally spaced recesses, ones on different rollers being generally aligned to receive said lower chord, a set of movable clamping bars located above said rollers, having laterally spaced gripping troughs adapted to cooperate with said roller recesses to selectively grip said bottom chord, two sets of laterally movable roller wheels having stationary baseplates associated therewith and being longitudinally spaced along a top chord side of said support platform, a first set positioned below or on an underside of said top chord and a second set positioned above or over said top chord, a set of clamping fingers interposed between said second set of roller wheels actuatable to engage said top chord and clamp the top chord and web together against the lower set of roller wheels, pneumatic means associated with said movable clamping bar, said first and second set of roller wheels and said clamping fingers, responsive to actuation of electrical controls firstly, to grip the lower chord, secondly, to laterally press said respective lower and upper sides of the top chord against said stationary plates, thirdly to clamp said top chord and web together, and welding means operative to weld said top chord to said web.
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