Grab
Product Introduction
Applications of Four‑Rope Grab
The four‑rope grab is mainly used in conjunction with overhead travelling cranes for handling various loose bulk materials, including loading, unloading, stockpiling, and feeding.
Types of Four‑Rope Grab
Depending on the grab volume and the specific gravity of the material being handled, we typically classify four‑rope grabs into four types: light‑duty, medium‑duty, heavy‑duty, and extra‑heavy‑duty.
Working Principle of Four‑Rope Grab
On the overhead travelling crane, two separate double‑rope drums are installed. Each drum draws out two wire ropes.
One pair of wire ropes is fastened to the inclined shells (or lifting rings and rope clamps) at both ends of the grab balance frame – these serve as the supporting ropes.
The other pair of wire ropes acts as the closing ropes.
These ropes pass through rope guides, head sheaves, and lower beam sheaves to form a pulley system that opens and closes the grab.
At the start, the supporting ropes lift the grab to the appropriate height, then the closing ropes are paid out.
Under the weight of the lower beam, the shells pivot around the lower beam main shaft and begin to open. The opening continues until the stop blocks on the two cheek plates strike each other – this is the maximum open position.
When the grab opens, the center distance between the upper beam sheaves and the lower beam sheaves increases.
The supporting ropes then lower the open grab onto the bulk material.
The closing ropes are drawn in, returning the center distance between the upper and lower beam sheaves to its original position – this completes the closing (grabbing) of the material.
The closed shells are now filled with material. Finally, both the supporting ropes and the closing ropes are lifted simultaneously, raising the entire grab. The crane moves the loaded grab to the discharge point, where the grab is opened to release the material.
Product Specifications
| model | Grab bucket volume m ³ | Grab bucket type | Material specific gravity (t/m³) | Grab material weight t | Wheel ratio | Steel rope diameter mm | Opening and closing time second | Equipped with traveling tonnage | Pulley diameter mm | Self weight of grab bucket t | Total height of grab bucket H(mm) | Maximum opening size D (mm) | Bucket size axbxh | remark |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| U1 | 1 | heavy | >1.8-1.9 | 1.8-1.9 | 5 | φ14 | 14 | 5 | φ350 | 2.065 | 2635 | 2544 | 1850×1150×673 | |
| U2 | 1.5 | middle | >1-1.8 | 1.5-2.1 | 5 | φ14 | 12.5 | 5 | φ350 | 2.235 | 2765 | 2700 | 2150×1250×745 | |
| U3 | 2.5 | light | >0.5-1 | 1.25-2.5 | 3 | φ14 | 8 | 5 | φ350 | 2.285 | 2985 | 3200 | 2350×1500×927 | |
| U4 | 2 | heavy | >1.8-2.9 | >3.6-5.8 | 5 | φ18 | 15 | 10 | φ500 | 3.898 | 3184 | 3070 | 2410×1320×826 | |
| U5 | 3 | middle | >1.0-1.8 | 3-5.4 | 5 | φ18 | 15 | 10 | φ500 | 4.4 | 3301 | 3200 | 2650×1550×900 | |
| U6 | 5 | light | >0.5-1 | >2.5-5.0 | 3 | φ18 | 10 | 10 | φ500 | 4.616 | 3549 | 3790 | 2950×1900×1090 | |
| U7 | 3 | heavy | >1.8-2.9 | >5.4-8.7 | 5 | φ21.5 | 15.3 | 15 | φ610 | 6.284 | 3726 | 3326 | 2616×1700×886 | |
| U8 | 4.5 | middle | >1-1.8 | >4.5-8.1 | 5 | φ21.5 | 15.3 | 15 | φ610 | 6.988 | 3946 | 3756 | 2956×1800×1041 | |
| U9 | 3 | middle | 1-2 | 3-6 | 5 | φ18 | 16.2 | 10 | φ500 | 4.431 | 3315 | 3200 | 2500×1722×630 | |
| U21 | 2.5 | light | 0.86 | 2.15 | 4 | ①16 | 10.3 | 5 | φ400 | 2.83 | 3350 | 3150 | 2150×1500×920 | |
| U25 | 3 | middle | >1-1.7 | 3-5.4 | 5 | φ19.5 | 11 | 10 | φ500 | 4.868 | 3172 | 3400 | 2400×1748×780 | |
| U26 | 3 | middle | 1.7 | 5.13 | 5 | φ19.5 | 11 | 10 | φ500 | 5.03 | 3172 | 3400 | 2400×1748×780 | toothed |
| U27 | 2 | middle | >1-1.2 | 2-2.4 | 5 | φ16 | 12 | 5 | φ400 | 2.5 | 2860 | 3000 | 2150×1500×820 | |
| U41 | 4 | heavy | >2.5 | 10 | 5 | φ27 | 14 | 20 | φ700 | 8.045 | 4215 | 4200 | 2800×1800×930 | |
| U43 | 1 | heavy | >2-3 | 2-3 | 5 | φ16 | 11.6 | 5 | φ400 | 2.318 | 2662 | 2600 | 2100×1092×577 | |
| U44 | 1 | heavy | >2-3 | 2-3 | 5 | φ16 | 11.6 | 5 | φ400 | 2.370 | 2662 | 2600 | 2100×1092×577 | toothed |
| U45 | 1.5 | middle | >1-1.9 | 1.5-2.85 | 5 | φ16 | 11.6 | 5 | φ400 | 2.515 | 2667 | 2600 | 2100×1392×577 | |
| U46 | 1.5 | middle | >1-1.9 | 1.5-2.85 | 5 | φ16 | 11.6 | 5 | φ400 | 2.448 | 2667 | 2600 | 2100×1392×577 | Balance the beam and open it up |
| U47 | 3 | light | 0.92 | 2.75 | 3 | φ16 | 7.4 | 5 | φ400 | 2.414 | 2926 | 3000 | 2200×1796×841 | |
| U47A | 2.5 | light | 0.92 | 2.3 | 3 | φ16 | 7.4 | 5 | φ400 | 2.167 | 2926 | 3000 | 2200×1600×841 | |
| U48 | 2 | heavy | >2-3 | 4-6 | 5 | φ19.5 | 16.2 | 10 | φ500 | 3.927 | 3315 | 3200 | 2500×1396×680 | |
| U48A | 2 | heavy | >2.1-2.6 | 4.2-5.2 | 6 | φ19.5 | 15.2 | 10 | φ350 | 4.020 | 3160 | 3000 | 2260×1300×875 | |
| U49 | 2 | heavy | >2.7 | 5.385 | 5 | φ19.5 | 15.6 | 10 | φ500 | 4.663 | 3530 | 3300 | 2500×1398×680 | |
| U50 | 3 | middle | >1-2 | 3-6 | 5 | φ19.5 | 16.2 | 10 | φ500 | 4.273 | 3315 | 3200 | 2500×1896×680 | |
| U51 | 3 | middle | 1-2 | 3-6 | 5 | φ19.5 | 16.2 | 10 | φ500 | 4.394 | 3315 | 3200 | 2500×1896×680 | toothed |
| U52 | 6 | light | 1 | 6.04 | 3 | φ19.5 | 9.5 | 10 | φ500 | 3.960 | 3615 | 3700 | 2800×2196×1050 | |
| U53 | 3 | heavy | 2.5 | 7 | 5 | φ23.5 | 14 | 15 | φ600 | 6.860 | 3850 | 3400 | 2720×1600×850 | |
| U54 | 3 | heavy | 2.5 | 7 | 5 | φ23.5 | 14 | 15 | φ600 | 7.229 | 3850 | 3400 | 2700×1600×850 | toothed |
| U55 | 4.5 | middle | 1.7 | 7.65 | 5 | φ23.5 | 16.3 | 15 | φ600 | 7.405 | 4130 | 4050 | 3000×1992×850 | toothed |
| U63 | 3 | middle | 1-2 | 3-6 | 5 | φ19.5 | 14.2 | 10 | φ500 | 4.306 | 3315 | 3200 | 2500×1396×680 | Parallel beams open |
| U67 | 1.5 | middle | 1-1.9 | 1.5-2.85 | 5 | φ16 | 9 | 5 | φ400 | 2.468 | 2968 | 2800 | 2120×1300×698 | |
| U69 | 1.5 | middle | 1-1.9 | 1.5-2.85 | 5 | φ16 | 11.6 | 5 | φ400 | 2.544 | 2867 | 2600 | 2100×1392×577 | toothed |
| U101 | 0.75 | overweight | >2.5-3.3 | 1.8-2.4 | 6 | φ16 | 11.9 | 5 | φ400 | 2.479 | 2735 | 2340 | 1650×1054×540 | |
| U102 | 0.75 | overweight | >2.5-3.3 | 1.8-2.4 | 6 | φ16 | 11.9 | 5 | φ400 | 2.546 | 2735 | 2340 | 1650×1054×620 | toothed |
| U103 | 3 | middle | 1-1.9 | 5.2 | 6 | φ19.5 | 11.9 | 10 | φ500 | 5.586 | 3443 | 3400 | 2400×1640×850 | toothed |
| U105 | 1 | heavy | 1.7-2.5 | 1.7-2.5 | 6 | φ16 | 11.8 | 5 | φ400 | 2.506 | 2835 | 2530 | 1800×1238×600 | |
| U106 | 1 | heavy | 1.7-2.5 | 1.7-2.5 | 6 | φ16 | 11.8 | 5 | φ400 | 2.568 | 2835 | 2530 | 1800×1238×600 | toothed |
| U160 | 1 | heavy | 1.7-2.5 | 1.7-2.5 | 6 | φ16 | 11.8 | 5 | φ400 | 2.506 | 2835 | 2530 | 1800×1238×600 | |
| U109 | 1.5 | middle | 1.0-1.7 | 1.5-2.55 | 5 | φ16 | 11.6 | 5 | φ400 | 2.549 | 2935 | 2740 | 1950×1444×655 | |
| U110 | 1.5 | middle | 1.0-1.7 | 1.5-2.55 | 5 | φ16 | 11.6 | 5 | φ400 | 2.615 | 2935 | 2740 | 1950×1444×655 | toothed |
Outline Structure Diagram
A four rope grab generally consists of four parts:1. Head 2. Beam 3. Pull rod 4. Bucket

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