| 摘要 |
<p>Apparatus for fabricating wood trusses having upper chords, lower chords, and web members, and more particularly for fabricating flat floor trusses. The apparatus has an elongate frame carrying a first series of supports for supporting the upper chord members and a second series of supports for supporting the lower chord members. A press is movable laterally along each chord from support to support to drive nailing plates into the wood members from above and below. Each support has a base, a vertical plate extending up from the base, and arms cantilevered from the vertical plate. Each support is movable longitudinally along the frame so as to be selectively positioned along the frame to support the wood members at this intersection. These supports are selectively securable to the frame in their selected positions with the vertical plates of the first and second series of supports in back-to-back relation with one another. In each support, the included angle between the bottom surface of its base and the inner face of its vertical plate is slightly greater than 90 DEG so that upon securing the bases of back-to-back supports to the frame, the vertical plates of these back-to-back supports are drawn together in face-to-face relation and preloaded so as to resist outward forces imposed on the cantilever arms of the supports during jigging and clamping of the wood members to the supports. A pneumatically operated clamp is also disclosed which holds the ends of the chords and an end web member in desired position, this clamp being movable to a retracted position to facilitate removal of the completed truss from the apparatus. An arrangement for biasing the press inwardly toward the supports as the press moves laterally is also disclosed so as to maintain press actuation switches carried by the press and switch actuators carried by the supports in desired operating position relative to one another.</p> |
