The single-rope remote control grab is a high-performance grabbing device specially designed for bulk cargo handling, widely used in ports, docks, yards, and bulk material processing plants. This grab operates with a single-rope system, featuring a compact structure and flexible control, making it especially suitable for crane lifting mechanisms with a single drum. Its design combines mechanical, hydraulic, and wireless remote control technologies, offering high reliability, safety, and ease of operation.
Main Components
The ENJUE remote control grab consists of the following 11 main functional units
| No. | Item | Descrption |
|---|---|---|
| 1 | Suspension | Connect the two closed ropes and the lifting rope to hook up with the crane |
| 2 | Grab head | Houses the upper roller block and is equipped with hardened steel rope bell-mouths for closing rope guidance |
| 3 | Pressure rod | Connect the scoops and the grab head, forming the counterpoint structure for closing rope guidance |
| 4 | Mobile traverse | Houses the lower roller block of the lifting block system; transmits closing rope forces to the piston rods of the locking cylinders |
| 5 | Rope compensation frame | Connected to the mobile traverse in a pendulum fashion; automatically compensates for grab tilting to ensure even load distribution |
| 6 | Traverse | Serves as the pivot connection for the scoops and houses the hydraulic and electric systems |
| 7 | Locking cylinders | Connect the mobile traverse and the traverse; transmit closing forces to the scoops and enable hydraulic unlocking for opening the remote control grab |
| 8 | Scoops (grab shells) | Directly perform bulk material picking; spill plates provided in the scoops can be opened when handling heavy bulk materials to prevent overload |
| 9 | Electric system | Housed in a steel plate enclosure, supplies power to the remote control and solenoid valve |
| 10 | Hydraulic system | Housed inside the traverse, drives the action of the locking cylinders |
| 11 | Radio remote control system | Comprises a transmitter and a receiver, enabling remote control of grab closing and opening operations |
Suspension and Connection Method
The suspension device connects two closed ropes and one lifting rope, and is directly hooked onto the crane hook using the provided oval suspension ring.
Safety Tip: For operational safety, the hook must be equipped with an anti-slip device (like a safety latch) to prevent the grab bucket from accidentally coming off.
The remote control grab bucket head has a built-in upper pulley set with a three-fold winding method, which reduces the load on the lifting rope and improves the system's mechanical efficiency. A hardened steel funnel-shaped rope guide is installed at the closed rope entry, effectively preventing wire rope wear and extending the rope's service life.
Force Transmission and Grab Principle
The closing action of the remote control grab relies on the hoisting rope to lift it:
The hoisting rope is wound by the crane drum, pulling the grab head upward;
The head transfers the force to the bucket segments through the pressure rods;
Meanwhile, the closing rope passes through the pulley set at the lower part of the moving beam, transmitting the closing force to the piston rod of the
Automatic Tilt Compensation Mechanism
The ENJUE remote control grab is equipped with a wire-rope compensation frame that is connected to the movable beam like a pendulum. When the grab tilts during operation (such as due to uneven load or ship rocking), the compensation frame automatically adjusts to ensure that the pulling force of the closing ropes is always transmitted vertically and centered to the movable beam. This prevents wear on the wire ropes or grab jams caused by uneven loads, significantly improving operational stability and rope lifespan.
Shovel Blade Design and Overload Protection
The shovel blade is the working part that comes into direct contact with the material and is made of high-strength wear-resistant steel. Its structural design fully accounts for the characteristics of different materials.
For heavy bulk materials (like ore, scrap steel, etc.), spill plates can be installed inside the shovel blade. When the weight of the grabbed material approaches or exceeds the rated load, the spill plates can automatically open to release part of the material. This effectively prevents overload on the grab bucket and lifting mechanism, providing mechanical overload protection and improving the safety of both the equipment and the operation.
Remote Control Grab Bucket Opening Principle and Hydraulic Unlocking System
The remote control grab bucket opens using a hydraulic unlocking and gravity self-opening method. The process is as follows:
When the bucket needs to be opened, the operator sends an open command via radio remote control;
The receiver activates the solenoid valve, and the hydraulic system supplies oil to the locking cylinder to unlock the piston rod;
Under the combined weight of the beam, bucket flap, and remaining material, the piston rod is pulled out, and the bucket flap automatically opens to discharge the load;
If the remote control system or electrical components fail, the hydraulic system has an emergency manual switch, allowing manual unlocking of the bucket on-site to ensure operability in emergencies.
Electrical System and Battery Management
The electrical system of the ENJUE remote control grab is integrated within a steel protective casing, offering good dust and moisture resistance, making it suitable for harsh environments like ports and yards.
Power Battery: Nickel-cadmium (Ni-Cd) battery pack, providing power for the transmitter and solenoid valve;
Continuous Operation Time: Depending on usage frequency, it can last up to 24 hours;
Charging Method: Comes with an intelligent charger that can simultaneously charge both transmitter and receiver batteries;
Charging Time: About 12–14 hours;
Power Compatibility: Supports 110V or 220V AC input. The charger can automatically detect and adapt to the input voltage without manual switching.
Hydraulic System and Emergency Operation
The hydraulic system of the remote control grab is installed entirely inside the crossbeam, with a compact layout and reliable protection. The main hydraulic components include:
- Locking cylinder
- Oil tank (including hydraulic oil)
- Control valve block (electromagnetic directional valve)
- Connecting hoses
The remote control grabs hydraulic circuits that use high-pressure hoses to connect the locking cylinder with the oil tank and control valve block. Besides normal remote operation, the system also has an emergency manual switch. If the wireless remote fails or there's an electrical fault, operators can manually control the solenoid valve to forcibly open the remote control grab, preventing material from getting stuck.
Transmitter Configuration and Operating Modes
The radio remote control grab transmitter can be flexibly configured according to on-site operating habits:
Portable Mode: The operator wears it via a neck strap, facilitating movement and operation within the work area;
Fixed Mode: The remote control grab's transmitter is fixed in the crane cab and continuously powered by an external power adapter (power module required);
In both modes, the transmitter can operate continuously for approximately 24 hours, meeting the continuous operation requirements of a full work shift.
Shovel Blade Design and Overload Protection
The shovel blade is the part that directly contacts the material, made from high-strength wear-resistant steel, with a design that takes into account the characteristics of different materials.
For heavy bulk materials like ores or scrap steel, the inside of the shovel blade can be equipped with spill plates. When the weight of the material being grabbed approaches or exceeds the rated load, the spill plates can automatically open to release some of the material. This effectively prevents overload of the remote control grab bucket and lifting mechanism, providing mechanical overload protection and enhancing the safety of both the equipment and the operation.
