Call it Cranegard, or call it a clamp-on, mechanically actuated, force control and overload protection switch. Your choice. 

Dowload the Brochure (pdf)

Easy to install--
Clamps directly on hoist or crane wire rope. No need to cut rope or interrupt service.

Versatile--
Each Cranegard can include from one to four switches, each with a preset load limit.

Affordable, effective warning system--
Cranegard's preset switches activate a warning light or audible alarm or interrupt a crane's power source when cable loads reach specified levels.

OPTIONS
Weatherproof low differential travel switch--Cranegard system can accommodate up to four of these switches.

Explosion proof switch--For use in hazardous locations (Class I, Div I, groups C & D; Class II, groups E, F & G).

Ultimate safety factor: 2:1 (1.8:1 for metric capacities)

Cable: Should be IWRC (Independent Wire Rope Core) with as many strands as possible.

Calibration: Performed with rope diameter specified on the order.