Portable jig for assembling prefabricated building structures

Claim 1

A jig for assembling a prefabricated building wall or similar structure comprising means for supporting a plurality of first structural members in generally spaced parallel relationship to each other and at least one second structural member therewithin, generally normal to and in end-to-side engaging relationship to the first structural members; said supporting means including a relatively rigid frame including first and second spaced elongated generally parallel supporting members adjacent each of which is adapted to be supported one of the first structural members, means for forcing the first structural memebers toward each other to thereby tightly clamp the second structural member therebetween, said forcing means including first and second relatively spaced, opposing and aligned clamping members carried by said respective first and second supporting members with each being adapted to abuttingly engage an associated one of the first structural members; said clamping members normally setting-off therebetween a first clamping distance corresponding to the external distance between the first and second structural members, means for step-wise adjustably increasing the first distance to a second distance corresponding to the total of the first distance and the thickness of one of the first structural members, said step-wise adjusting means being defined by a rod of said first clamping member mounted for sliding movement between first and second clamping positions toward and away from said second clamping member by a fixed incremental distance corresponding to the thickness of the one of the first structural members thereby defining with the second clamping member said first and second distances, means for locking said rod at each of said first and second positions, said forcing means further including a flexible cable connected between said first and second clamping members, and means for tensioning said flexible cable to draw said clamping members into intimate tight clamping engagement with the first structural members in both the first and second clamping positions thereof.