4" Chain Anti Back-up Device, Part # 8702Designed for 4 I beam systems, these anti backup devices prevent trolleys from rolling backwards on vertical inclines. Anti backup stop arms are mechanically lifted by the passing trolley brackets as they ride up the incline. Should the power fail, the stop arms will provide a positive stop. Stop arms are equipped with rubber bumpers to reduce noise. Ships in: 3 5 days Click here for part dimensions and more information. Can't find a part? All of

shake proof washer and jam nut

and (6) 56576

This chain is used on systems with high chain pull

Details Designed for 4” I-beam systems

and a rugged cast iron body construction

Made of malleable or ductile iron

This trolley assembly consists of two half trolleys with full ball bearing complement type wheels and a standard "I" attachment

These 4" full ball bearing complement type trolley wheels have open bearings with deep case hardened races and case hardened ball bearings

This 4” trolley with a 4" drop has a load capacity of 400 pounds per single trolley

abrasive action and shock loads

Trolleys are equipped with a triple labyrinth seal and wheels are bolted for easy replacement

This 3” trolley with a 5 1/2" drop has a load capacity of 200 pounds per single trolley