latch 36 relative the latch plate 19 until the end 13 of the latch pin is latched within a groove 39 defined by the distal end of the latch 36 the edges 40 and 41 of latch plate 19 are flared outwardly about lines 42 and 43 respectively to facilitate the guidance of the side 15 of the first beam 10 between the latch plates 18 and 19 the latch plates 18 and 19 are secured adjacent the sides 20 and 21 of the beam 22 by means of screws nails or any other suitable anchoring means the stop 27 and a corresponding stop 44 for the latch 36 are either stamped from the metal of the latch plates 18 and 19 respectively or are fabricated separately and welded at the correct location on the latch plates 18 and 19 fig6 is a side elevational view of the pintle at the bottom of a constructional beam 10 a pintle 45 is rigidly secured to the sidewall 46 of an inverted metallic saddle 47 the saddle 47 is mounted upon the bottom of the beam 10 by means of wood screws 48 having threaded shanks 49 and cooperating nuts 50 the saddle 47 also has a sidewall 51 having a pintle 52 disposed thereon alternatively the saddle may be secured to the bottom of the beam by means of bolts not shown passing through aligned apertures defined by the sidewalls 46 and.