latch member is positioned at approximately a 90 u00b0 angle thereto preferably each keeper member is formed with a second hook opening 17 39 and a second lock opening 21 39 the latch member is also formed with a second hook member 16 39 the keeper member and the latch member are formed with openings 18 39 for the receipt of fasteners such as screws 19 39 the lock means 7 39 includes an elongated inverted 34 l shaped 34 member having a relatively straight portion 9 39 with a short catch member 8 39 in order to prevent the lock means from separating from the keeper member the openings 3 39 and 21 39 which are an open slot are formed so that the slot is narrower at the opening a than at inner edges 34 and 35 the end 8 39 of the lock member is dimensioned to register with the wide opening of the slot and to have an edge length 36 greater than the width of the slot at its edge to prevent accidental horizontal movement and unlocking the shape of the opening is immaterial and may be a portion of a circle so long as the slot opening 34 a 34 is smaller than the edge length 36 operation of the form of the invention is the same as previously described keeper 1 39 is.