| 摘要 |
A plurality of form sections are connected together end-to-end for casting rectangular concrete beams on edge in horizontal position. Each form section is mounted on transverse base beams secured to a concrete foundation or floor. One side form in each form section is mounted on trolleys to roll out on the base beams away from the opposite side form. Provision is made for longitudinal expansion movement of the side forms when they are heated to cure the concrete. Each trolley is equipped with a special locking device to hold the rollout side form in different casting positions for casting beams of different widths. A grooved roller in the locking device engages a bar on a base beam to perform the three functions of locking the trolley against rollout, holding the trolley down to prevent uplift from the fluid pressure of the wet concrete and permitting movement of the locking device with longitudinal expansion and contraction of the rollout side form.
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