Introduction
The bracket-type over-hoisting limit switch consists of a bracket, rotating shaft, return spring, limit switch and mounting bracket, fixed directly below the electric hoist drum via the bracket. During normal operation, the bracket remains horizontally under the action of the return spring, and the limit switch is closed; when the hook pulley block rises to the limit position, the top of the pulley frame lifts the bracket, which rotates around the shaft by a certain angle, actuating the limit switch to cut off the hoisting control circuit and stop the hook from rising. During lowering, the bracket automatically resets under the spring action, and the limit switch recloses. The product adopts a fully sealed cast aluminum or steel-plate welded housing with protection grade IP65; the limit switch uses imported or domestic high-quality elements with large contact capacity and long service life. As hoisting terminal protection, the bracket-type limit switch is unaffected by wire rope slack, weight falling off and other factors, with higher reliability than weight-type, widely used in various electric hoists and lifting trolleys.
Our Advantage
Reliable mechanical triggering: Adopting pure mechanical bracket triggering structure, independent of electrical sensors, unaffected by wire rope slack, weight falling off, electromagnetic interference and other factors, with direct and reliable triggering, serving as the last safety barrier for over-hoisting protection.
Double protection enhances safety: Often used in conjunction with weight-type or multi-function travel limit switches to form two-stage over-hoisting protection; even if the first-stage limit fails, the bracket-type still operates reliably at the terminal position, completely eliminating serious accidents of hook over-hoisting and wire rope breakage.
Simple structure with easy installation: Overall structure consists of bracket, shaft, spring and switch, with few parts and low failure rate; fixed below the drum via mounting bracket with bolts, no need to modify the hoist body, convenient for both new installation and renovation, with extremely low maintenance cost.
Adjustable trigger stroke with strong adaptability: Bracket trigger angle and stroke can be flexibly set by adjusting screws or limit switch position, adapting to different pulley frame sizes and lifting margin requirements, compatible with 0.5t~100t various electric hoists with extremely strong versatility.
Fully sealed protection for harsh environments: Limit switch is built inside a fully sealed housing with protection grade IP65, dust-proof, moisture-proof and oil-proof; bracket and shaft adopt stainless steel or galvanized anti-corrosion treatment, ensuring long-term stable operation in dusty and humid harsh environments such as metallurgy, foundry and ports.
Specification
| Parameter | 0.5~5t | 10~20t | 32~50t | 80~100t |
| Applicable Capacity | 0.5/1/2/3/5t | 10/16/20t | 32/50t | 80/100t |
| Bracket Size | ~200×150mm | ~300×200mm | ~400×300mm | ~500×400mm |
| Trigger Stroke | 30~50mm（Adjustable） | 50~80mm（Adjustable） | 80~120mm（Adjustable） | 100~150mm（Adjustable） |
| Trigger Angle | 15°~30° | 15°~30° | 15°~30° | 15°~30° |
| Response Time | ≤0.1s | ≤0.1s | ≤0.1s | ≤0.1s |
| Reset Mode | spring auto reset | spring auto reset | spring auto reset | spring auto reset |
| Limit Switch Rating | AC 380V / 5A | AC 380V / 5A | AC 380V / 10A | AC 380V / 10A |
| Contact Form | 1NO+1NC | 1NO+1NC | 1NO+1NC | 1NO+1NC |
| Mechanical Life | ≥ 1M times | ≥ 1M times | ≥ 1M times | ≥ 1M times |
| Installation | bolted below drum | bolted below drum | bolted below drum | bolted below drum |
| Housing Material | cast aluminum | steel welded | steel welded | steel welded |
| Protection Grade | IP65 | IP65 | IP65 | IP65 |
