Scissor lifts are a type of mobile elevated work platform (MEWP) easily recognized by their signature crossed beams, or scissor legs. These machines provide more flexibility than standard scaffolding with a wider work platform than a boom lift.
Scissor lifts raise workers vertically so they can easily reach an elevated area. And if you work in construction, maintenance, warehousing or agriculture, you’ll likely see or use a scissor lift at some point.
To ensure your scissor lift is well-maintained and used safely, it’s important to know how it works. In this article, you’ll learn how a scissor lift works and the components of these pieces of equipment so you’ll have a better chance of identifying issues before they cause costly delays or accidents.
How Do Scissor Lifts Work?
Scissor lifts work differently from other lifts because of their signature scissor-leg design. Although exactly how different scissor lifts operate may vary, most follow the same basic steps.
How the Lift Mechanism Works
1. An operator turns on the power source.
2. Compressed air or hydraulic fluid moves through the cylinder(s).
3. The cylinder pushes the crossed beams apart, like opening a pair of scissors.
4. As the scissor legs expand, the platform rises.
5. To lower the platform, the operator releases the pressure in the cylinder.
6. The cylinder pulls the scissor legs back together, lowering the platform.
Who Needs to Know How a Scissor Lift Works and Why?
When a scissor lift is on your property or project site, safety must be a top priority. Everyone working on or near the scissor lift needs to know how to safely operate it. Plus, the scissor lift must remain in safe, working condition.
There are several people who need to know how a scissor lift works, so they can ensure everyone’s safety:
- Scissor Lift Operators: Knowing how the lift works will help you complete pre-operation safety checks, handle problems that occur while using the lift, and communicate issues to management or maintenance.
- Managers: Whether you buy or rent a scissor lift, you need to understand how they work. If there’s a malfunction, you’ll be better able to communicate with your team or rental equipment provider to solve the problem.
- Equipment Maintenance Technicians: Having a deep understanding of how a scissor lift works will help you troubleshoot issues and make the right repairs.
Key Components of a Scissor Lift
The first step to learning how a scissor lift mechanism works is to familiarize yourself with the parts of a scissor lift. Luckily, most scissor lifts have the same basic components. Review the information below before continuing.
Base
The base moves the entire lift and keeps it stable when the platform is raised. The base has its own set of controls, as well as tracks that guide the bottom of the scissor legs as they expand. A strong, well-maintained base helps ensure the platform moves smoothly without tipping over.
Platform
The platform, also known as a lift table, lifts workers and materials to the elevated work area. Scissor lift platforms are often close to the same length and width as the base. Some scissor lifts have platforms that can extend beyond the base.
The platform typically has guardrails on all sides to help prevent workers from falling. It also contains a set of controls so operators can adjust the lift while on the platform.
Scissor Legs
The legs are what give a scissor lift its name. These crossed beams connect the platform to the base and are hinged in a criss-cross pattern. When the lift is raised, the legs open like a pair of scissors and the Xs become more narrow. Then the lift is lowered, the legs collapse to their full width.
Cylinders
Depending on the size of the lift, a scissor lift may have one or multiple cylinders. The cylinders are attached within the scissor legs and are filled with either hydraulic fluid or compressed air. When the platform is raised, pressure builds up in the cylinder, pushing it outward and expanding the scissor legs.
- Hydraulic Scissor Lifts: If the cylinders are filled with hydraulic fluid, the scissor lift is known as a hydraulic scissor lift.
- Pneumatic Scissor Lifts: If the cylinders are filled with compressed air, it’s known as a pneumatic scissor lift.
Power Supply
Scissor lift engines can be battery powered or run on fuel, like diesel. The engine is what powers the scissor lift mechanism and allows the lift to be driven across the project site.
- Electric Scissor Lifts: Battery powered lifts run purely on electricity. They are great for indoor use because they do not create any harmful fumes. However, they often have a lower load or weight capacities than diesel-fueled scissor lifts.
- Diesel or Dual Fuel Scissor Lifts: Diesel scissor lifts, such as rough terrain scissor lifts, are larger and heavier than electric scissor lifts. They can also usually reach higher elevations. This makes them ideal for outdoor projects that need to lift heavy loads to great heights.
Flow Control Valve
The flow control valve controls the flow of hydraulic fluid or compressed air into and out of the cylinders. This keeps the platform from rising or lowering too quickly.
Down Valve
The down valve allows the platform to be lowered back to the base. It is connected to the power supply, which means when the operator uses the controls to lower the platform, the valve will open.
When the down valve opens, the hydraulic fluid or compressed air leaves the cylinder. When the pressure in the cylinder decreases, the cylinder pulls the scissor legs back together.
How Are Scissor Lifts Controlled?
On every scissor lift, there are two sets of controls: one on the base and one on the platform. Refer to your user’s manual or ask your rental equipment provider for training on how to use your specific model.
- Learn More: How to Operate a Scissor Lift Safely
Base Controls
The controls on the base of the scissor lift allow you to operate the lift from outside of the platform. They are especially important for spotters who help navigate from the ground.
- Emergency Stop (E-Stop) Button: Pull out the emergency stop button to use the scissor lift. Push in the e-stop button to immediately turn off the lift in an emergency.
- Key Switch: The base’s key switch allows the lift to be controlled from the base controls panel, the platform control panel or both.
- Raise/Lower Switch: Use this to raise or lower the platform.
- Indoor/Outdoor Buttons: Some lifts have pre-sets that adjust the lift for optimal operation.
Platform Controls
Scissor lift operators primarily use the platform controls. The control panel on the platform may include:
- Emergency Stop (E-Stop) Button: Pull out the emergency stop button to use the scissor lift. Push in the e-stop button to immediately turn off the lift in an emergency.
- Key Switch: Turn the key switch to turn the lift on or off during normal operation.
- Drive/Steer Control: Also known as a mode selector, this lets you either drive the lift or raise/lower the platform. You can’t raise/lower the platform while in driving mode.
- Joystick: For most scissor models, pull back (toward you) on the joystick to raise the platform. Push forward on the joystick to lower the platform.
- Other Controls: Depending on the model, other controls may give you the option to adjust speed, steer, or raise the platform to a predetermined height.
Easily Rent a High-Quality Scissor Lift from Herc Rentals
When you need an easy-to-use scissor lift, call on the equipment experts at Herc Rentals. We’ll help you find the right high-quality compact electric, electric or rough terrain scissor lifts perfect for your project.
When you partner with Herc Rentals, you get the peace of mind that your scissor lift will be in peak condition and ready to work. Our team will also save you the hassle and expenses that come with equipment ownership through our convenient delivery and on-site repair services.
Explore our broad selection of aerial solutions, including scissor lifts, or call us at 888-777-2700 to discuss options with an expert today.
