Scissor lift how does it work

Opening the down valve allows hydraulic fluid out of the cylinder at a controlled rate and lowers the lift table. An electric motor and hydraulic pump typically perform repetitive lifting and positioning, activated by the push of a button. In a pneumatic system, scissor lift tables can be connected to on-site compressed air systems, eliminating the need for hydraulics, motors, pumps, or electrical connections.

Durable airbags provide consistent and smooth height adjustment and lifting. A relief valve prevents pressure build-up and acts as overload protection. In some scissor lift configurations, the working platform of the unit can rotate to provide the operator with greater accessibility. In hydraulic units, table control is accomplished via an electric motor and hydraulic pump that perform repetitive lifting and positioning operations with the push of a button. To answer the question "How does a scissor lift work?

The platform on the top of a scissor lift mechanism can be of various sizes, shapes, and materials. Also known as a lift table, the platform is the working surface that bears the load of personnel or work objects that the scissor lift raises or lowers. Units that transport workers typically feature a platform with guard rails around its perimeter for fall protection.

Platforms without rails are typically designed for lifting or lowering materials and inanimate objects. The scissor legs are the crisscross array or pantograph configuration of fabricated metal struts that bridge the gap between the base and the platform. The maximum working height of the scissor lift mechanism will be dictated by the length of each scissor leg or the number of scissor legs. The scissor legs raise the platform as they constrict draw closer together and lower the platform as they expand and can be driven by different power sources depending upon the specified application.

These cylinders may be filled with hydraulic fluid hydraulic scissor lift or compressed air pneumatic pump system depending on the specification and the operating environment. An increase or reduction of pressure through these cylinders attached to the scissor legs actuates the raising or lowering action of the scissor legs and platform.

This foundational part of the scissor lift mechanism is a sturdy footing made up of strong, rigid brackets. The base is engineered with tracks to guide the rollers at the bottom of the scissor legs.

In conjunction with strong support from the base, these rollers ensure steady and stable raising and lowering of the unit. The size and configuration of the scissor lift base will depend on the model and its application. There is a range of power sources that can be specified to power a scissor lift. These can range from self-contained motors that run on different fuel sources to remote power packs. The selection of the most suitable power source will be dependent on the operating environment of the scissor lift.

The down valve controls the flow of compressed air or hydraulic fluid back to its reservoir. The speed of this flow dictates the speed at which the platform will descend. The power source is connected to the down valve that controls the rate of descent. Besides being the heart for the unit, the base is engineered to guide the rollers at the bottom of the scissor legs. Bases have a minimum size they have to adhere to, upon the size of the platform, the capacity, the amount of travel, and how the unit is being loaded and unloaded.

Scissor Legs. Bridging the gap between the bottom and the platform are the vertical scissor legs. The legs carry the platform through the different elevation changes. Hydraulic Cylinders. Raising and lowering the scissor lift is actuated by high pressure hydraulic cylinders.

On the common hydraulic scissor lift tables, the number of cylinders will typically vary from 1 to as many as 4 cylinders.

Power supply. Hydraulic lift tables are usually power-driven by diesel, gas or electrical motor. They can even be power-driven pneumatically via a high industrial compressor. Hydraulic scissor Lift Operation A hydraulic lift table raises and lowers once the hydraulic fluid is pushed into or out of the hydraulic cylinder. As hydraulic fluid is pushed into a cylinder, the cylinder strokes outward making the scissor legs apart.

Raising the scissor Lift. Raising a scissor lift since one finish of each the inner and outer connected to the bottom and platform, the platform rises vertically because the scissors legs close. How Does a Scissor Lift Work? Writer January 19, The essential parts There are five crucial parts of a scissor lift. How does it work? Image: Pixabay. Related Items aerial work platforms elevated work platforms mini power pack Scissor Lift. January 19, More in Business.

Read More. Scissor lifts enable operators to complete the same jobs faster and more securely without the setup time of other equipment, such as scaffolding or a tower, and without the dangerous instability of a ladder. Although the chance of a fall can never be completely eliminated when you work at any height, scissor lifts provide a safety harness or cable as well as a sturdy platform surrounded by a railing.

Sometimes you will hear of a scissor lift referred to by one of these names for its technical classification:. The lift is usually made of steel and includes a platform and railing supported by a beam — or bar-style struts. The way the struts hinge together makes the assembly look like several sets of connected scissor blades, and as they operate, they perform an open-close motion similar to scissors.

The X pattern actually has a technical name called a pantograph, and hydraulic mechanisms power the scissor action that enables the lift. Scissor lifts typically extend from feet vertically depending on the model, and the working heights tend to range between 20 and 40 feet, though there are models that move higher.

Certain scissor lifts may even be moved forward and backwards with the lift partially extended, but this should only be undertaken with great caution. Other types of aerial lifts, such as an articulated or telescoping boom, reach higher heights than standard scissor lifts, but the scissor lift is able to carry more weight and offers a functional work platform.

Some lifts sit on four wheels or legs and other models have outriggers that go into or onto the surrounding ground to add stability. Some machines are made to operate indoors, like those used for building maintenance or warehousing, while rough-terrain scissor lifts RTS can stand up to outdoor conditions and challenging paths. Some have non-marking tires while others do not. With many options within the same class of MEWP, the first step toward acquiring or renting a scissor lift is to consider what kind of work it will do and in what environments.

Matching the height, dimensions and other specifications of a scissor lift to the job and environment is not only a matter of logistics, but also efficiency and most importantly, safety.

The first step in getting a scissor lift in to do the job is to assess the site and goals, which will involve asking the following questions:.

It is a good idea to enlist professional help as you figure out which machine will fulfill your needs the best. Any dimension restrictions such as narrow aisles, or load requirements such as extra-heavy weight, need to be considered. You might need an ultra-quiet lift that generates no emissions and has non-marking tires, or it may need to be a lift that has a small, manageable step up to the platform and extends to a relatively low working height.

Along with the high ceilings of many structures come tall walls, and they both hold lights, artwork and other objects that must be accessed for maintenance and cleaning.

These wide-ranging indoor needs are served by electric scissor lifts, while gas and diesel-powered models can handle outdoor jobs. If your construction company builds average residential homes, you may never work much higher than at the standard height for one residential floor, a little more than 10 feet. Commercial floors are a little taller, about Your needs assessment should include present and future requirements for the machinery.

Anytime someone considers the purchase or rental of a piece of major machinery, they are making an investment especially when it enables the owner to break into new kinds of work. For example, if you are a brick mason who only bids on jobs for one-story buildings because your folding scaffolding limits the heights your crew can work at, a scissor lift could significantly increase the number of jobs your business could take on.