http://www.sstack.com/stable_stable-organizers_horse-blanket-saddle-pad-racks/easy-up-swing-out-blanket-bar/
The barn I work at has 12 of these racks… They have survived 3 years of abuse and have supported soaking wet size 87 heavyweight blankets without collapsing - BUT! I DID NOT install them with the cheap screws they came with, I took one to Lowe’s and found the largest diameter 2" lag screw that would fit thru the predrilled holes. All 12 are mounted on a 2x10 header in the barn, that is ~8’ off the ground. I have found that if I close the front of the blankets, and stand under the bar I want to hang the blanket on, I can “fling” the chest of the blanket up into the air and it will “float” down onto the bar. Saves me from having to drag a step stool around. I can usually flop them back off, too, without using a step stool. You DO have to make sure the blankets hang all the way to the “back” of the arm, flush with the wall. You will bend the arm if you try to support all the weight way out at the front of the arms. (A lesson kid bent one of the arms by leaving a blanket dangling over the end…)
Are they worth it? I dunno. I think you could accomplish the same thing using the hangers from Home Depot that SuckerForHorses linked… All you really need is something sturdy enough to support the weight of the blanket, with enough depth to hold the chest portion of the blanket. We never use the full 40" of the arms, only the 18" or so closest to the wall.