Spread-style coupler with supplemental lock system

A coupler comprising:

• first and second spaced-apart ribs each defining first and second bores, said first bore of said first rib aligned with said first bore of said second rib on a first pin-on axis, and said second bore of said first rib aligned with said second bore of said second rib on a second pin-on axis;
• a first hook assembly comprising a first hook adapted to receive a first associated attachment pin;
• a second hook assembly comprising a second hook adapted to receive a second associated attachment pin, said second hook assembly selectively pivotable relative to said first and second ribs toward and away from said first hook assembly;
• a screw jack assembly actuator operatively connected to said second hook assembly and adapted to pivot said second hook assembly selectively relative to said first and second ribs, wherein said screw jack assembly comprises:
• (i) a rotatable screw member comprising a driving head adapted for driving connection with a manual tool;
• (ii) a locking sleeve that is movable from an extended position to a depressed position and biased into said extended position, wherein said locking sleeve engages said screw member and restrains said screw member against rotation when said locking sleeve is in said extended position.

A coupler comprising:

• an upper portion defining a first pin-on axis and a second pin-on axis;
• a first hook adapted to receive a first associated attachment pin;
• a second hook adapted to receive a second associated attachment pin, said second hook movable relative to said upper portion toward and away from said first hook;
• a locking cam movable relative to said first hook between a retracted position and an extended position, wherein said locking cam at least partially blocks said first hook when in said extended position;
• an actuator operatively connected between said second hook and said locking cam, said actuator being operable between a first position and a second position, wherein:
• (i) when said actuator is operated from said first position to said second position, said actuator moves said second hook away from said first hook and moves said locking cam from said retracted position to said extended position;
• and, (ii) when said actuator is operated from said second position to said first position, said actuator moves said second hook toward said first hook and moves said locking cam from said extended position to said retracted position;
• a stop;
• and,
• a lock bar movable under force of gravity between a locked position and an unlocked position depending upon an angular orientation of said coupler, said lock bar comprising a stop face, wherein:
• (i) said lock bar stop face is located to engage said stop and prevent movement of said locking cam from said extended position to said retracted position when said lock bar is located in said locked position;
• and,
• (ii) said lock bar stop face is moved out of alignment with said stop when said lock bar is located in said unlocked position so that said locking cam is movable from said extended position to said retracted position when said lock bar is in said unlocked position.