A screw jack, also known as a mechanical jack, is a device that uses the transmission of a screw pair driven by human power, with the screw rod or nut sleeve serving as the lifting component. An ordinary screw jack supports heavy objects by means of the self-locking function of the screw thread. It has a simple structure, yet it features low transmission efficiency and a slow return stroke. The screw of a self-lowering screw jack does not have a self-locking function but is equipped with a brake. When the brake is released, the heavy object can be quickly lowered on its own, shortening the return time. However, this type of jack has a relatively complex structure. Screw jacks are capable of supporting heavy objects for long periods. The maximum lifting capacity has reached 100 tons, so they are widely used. When a horizontal screw is installed at the bottom, it can also enable the heavy object to move horizontally over a short distance.
In the industrial field, screw jacks play a crucial and diverse role. They are indispensable in construction sites, where they are often used to lift and position heavy building materials like steel girders and large concrete blocks. The ability to hold a load steadily over time is a key advantage, as it allows workers to carry out precise assembly operations without the constant worry of the load shifting. In manufacturing plants, screw jacks assist in the installation and alignment of heavy machinery. For instance, when installing a large printing press or a metal stamping machine, these jacks can delicately adjust the height and horizontal position of the equipment, ensuring optimal operation.
With the development of technology, modern screw jacks are evolving to meet more complex demands. Advanced materials are being used to improve durability and reduce weight. High-strength alloys for the screw and nut components can withstand greater loads without deforming, while lightweight materials for the jack’s housing make it more portable and easier to maneuver. Precision manufacturing techniques have also led to more accurate thread cutting, enhancing the smoothness of the lifting and lowering processes. This is especially important in applications where minute adjustments are required, such as in optical instrument assembly or precision mold installation.
Moreover, intelligent features are gradually being incorporated into screw jacks. Some models now come with sensors that can monitor the load, lift height, and even the temperature of key components in real-time. This data can be transmitted wirelessly to a central control system, enabling operators to remotely monitor and control multiple jacks simultaneously. In large-scale construction projects or industrial setups, this kind of intelligent management not only improves work efficiency but also enhances safety by providing early warnings in case of any abnormal situations, like overloading or component failure.
In the automotive repair and maintenance sector, screw jacks are a staple tool. They are used to lift vehicles, providing mechanics with access to the undercarriage for tasks like oil changes, tire rotations, and brake inspections. Smaller, more portable screw jacks have been developed specifically for this purpose, with features such as quick-release mechanisms and adjustable lifting pads to fit different vehicle models. Additionally, in the shipping and logistics industry, screw jacks are used to load and unload heavy cargo containers. Their ability to make small horizontal displacements helps in accurately positioning containers on trucks or in storage yards, streamlining the entire logistics operation.
Safety has always been a top priority in the design and use of screw jacks. Stricter safety standards have been established worldwide, covering aspects such as load limits, stability requirements, and emergency stop mechanisms. Manufacturers are constantly innovating to meet these standards, adding features like redundant braking systems and anti-slip bases. Training programs for operators have also been enhanced, ensuring that they are fully aware of the proper operation procedures, load capacities, and safety precautions when using screw jacks, minimizing the risk of accidents.
