Gas lift for a chair - device and principle of operation

Icer
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Icer November 10, 2018Specialization: master in the construction of plasterboard structures, finishing work and laying floor coverings. Installation of door and window units, finishing of facades, installation of electrical, plumbing and heating - I can give detailed advice on all types of work.

Gas lift is often an important design for any office or computer chair, on which the comfort of using the furniture largely depends. In the review I will tell you about the device of the gas cartridge and its main features. I will also describe the process of replacing a failed part with a new one, so that you can do the work yourself, using the article as instructions.

The gas lift is fixed in the crosspiece and connects the support part to the seat

Structure and design features of office chairs

All existing office chairs can be divided into the following groups.

For managers. They are distinguished by their large dimensions and solid appearance, most often upholstered in natural or artificial leather. They have the greatest number of functional capabilities, for example, a synchronizing mechanism that ensures repetition of the movements of the seated back and seat, mechanisms that regulate the depth of the seat, back resistance, negative tilt, etc.

Executive chairs are comfortable and sized.
For the staff. They must be comfortable and reliable, so when choosing them, the main attention is paid to the shape of the seat and backrest and the gas lift mechanism, and not to appearance. They are lightweight, which allows for a high level of mobility, and have modest functionality, which includes mechanisms that regulate the height of the armrests and seat, as well as the angle of the backrest. This group includes computer chairs and operator structures with armrests.
Note! Such chairs most often have fabric upholstery, which can be made in different colors.
For visitors. Such chairs must first of all be comfortable, beautiful and stable, and therefore they are devoid of any functionality. They often have four stationary legs, without a cross on wheels or a rotation mechanism.

A modern chair is a functional and comfortable piece of furniture.

Almost all models are equipped with armrests. Cheap designs are made almost entirely of plastic, while more expensive ones are made of stainless or anodized steel.

Despite the existing differences, all chairs consist of the following basic elements:

a five-beam cross, which is the basis of the entire structure and is made of plastic or metal;
rollers, plastic or metal, having an internal hinge and metal fastening;
pneumatic cartridge, or gas lift, which is the leg of the chair and provides elasticity;
a swing mechanism that helps fix the chair in one position and tilt;
piastra, which looks like a metal platform equipped with a lever, and is necessary for adjusting the height of the seat;
permanent contact connecting the seat and backrest and responsible for changes in the position of the latter.

Multifunctionality is the main criterion when choosing a chair.

Note! Expensive chair models are equipped with a mechanism with an offset axis, which ensures the smoothest swinging process.

Office chairs have the following features designed to make working at your desk more comfortable:

height adjustment, allowing you to choose the optimal seat height for each person;
changing the tilt of the backrest, ensuring constant contact of the back with it, even when the sitting position changes;
rotation around an axis and mobility created by rollers.

An office chair is a rather complex device and any of its structural elements can fail.

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Conclusion

Now you know all the main features of gas lifts for kitchen cabinets, you can choose the optimal model for your furniture and install it correctly using the recommendations from this review. The video in the article will help you understand even better some of the important nuances raised above. If you still have any questions, write them in the comments.

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May 5, 2022

Accessories,Kitchen

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What is

The gas lift used in office chairs is a device that is similar to the lifting mechanism of a dump truck, but smaller. Its other name is gas spring. Externally, it is a metal pipe with two parts of different sizes. The gas lift mechanism is fixed in the upper part to the base of the seat, in the lower part it is attached to the cross. The lifting height depends on the size of the pneumatic cartridge, the length of which varies from 13 to 16 cm. Gas lift functions:

Seat position adjustment. When you press the lever, the structure rises if you stand up a little to reduce resistance, or lowers under your body weight.
Reducing sudden load on the spine area. When lowered into the chair, the mechanism works as a shock-absorbing device. The seat is springy, significantly reducing the load on the spine.
Possibility of rotation 360 degrees. Due to the features of the system, you can easily reach objects that are at arm's length, located on both sides.

The hydraulic cylinder is configured for actions that are necessary when working simply at a desk or at a computer.

Purpose

Previously, gas lifts were used only in the construction of cars. They were placed on trunks and installed in doors. The devices take on the entire weight of the structure and protect it from damage. In the modern world, gas lifts have many more functions. They are used in various fields:

Furniture industry. First of all, this applies to products for the kitchen. Gas lifts make it easy and almost silent to open cabinet doors. They help prevent doors from closing on their own and save a lot of space. Lifts are also installed in office chairs and many other furnishings.
Construction. The devices are used in door mechanisms, window frames and glass display cases.
Medicine. Beds for proper care of non-ambulatory patients, equipment for restorative purposes - all this cannot be done without gas lifts.
Printing. The devices are installed on copiers, printers and other devices.

The operating principle of gas lift is based on the action of hydraulic shock absorbers and gas springs. When the door is opened manually by at least 10°, it moves independently to a right angle. The design is sealed, and the cylinder is filled with an inert gas, most often nitrogen. It creates the necessary pressure during compression. The mechanism will never need to be disassembled or repaired. Among the advantages it is worth noting the following:

open facades are firmly held at the highest point;
door movement is often automatically adjusted;
the opening process is silent;
high resistance to corrosion is observed;
wide range of designs.

Types of furniture cleaning, rules and nuances of using each of them
Despite many advantages, gas lifts also have disadvantages:

a high pressure gas source is required;
high cost for most copies.

Regardless of the shortcomings, gas elevators will be relevant for a very long time. Every year, many studies are conducted to refine and improve the device.

What it is

The gas lift, which is an integral part of office chairs, is a device that in its appearance resembles a truck body lifting system, but is slightly smaller in size. Another name for this device is a gas spring.

Externally, the gas lift for the chair is a metal pipe with a couple of parts of different sizes.

The mechanism of this gas spring is attached from above to the base of the seat, and from below it is attached to the crosspiece. The lifting height will depend on the size of the pneumatic chuck. Usually its length varies in the range of 13-16 centimeters.

It should be noted that the gas lift has 3 functions.

Dampening the shock load on the spine. The point is that when a person sits down in a chair, the mechanism works like a shock absorber, springing the seat and significantly reducing the load on the spine. Thanks to these properties, the chairs become significantly more comfortable and easier to use. That is, you can quickly sit down and get up without fear of back problems.
Adjusting the seat position. Using a pneumatic chuck, you can raise or lower the chair in a few seconds without making any serious effort. Simply press the lever from below, and the structure will either fall under the weight of its mass, or rise if you stand up from it, which will reduce resistance.
Possibility of circular rotation of the chair. This allows you to freely access everything that is located at a distance of up to 50 centimeters and turn where you want, if necessary. The special mechanism is designed in such a way that you can spin around its axis without any problems.

In fact, a gas lift is a special hydraulic cylinder designed specifically for office chairs.

What is gas lift

First, you need to understand for what purposes this node is used and what functions it performs.

The structure is installed in the crosspiece and fixed at the base of the seat; it is necessary for three main purposes:

Adjusting the seat position . Using a pneumatic chuck (another name for the unit in question), you raise or lower the chair in a matter of seconds without making any effort. Simply reach out and press the lever, after which you can either lower the structure under its own weight, or raise it by standing up slightly to reduce resistance.

The seat height can be adjusted to any person very quickly thanks to the gas lift

Damping the shock load on the spine . When you sit down, the system acts as a shock absorber, springing the seat and significantly reducing the load on the spine. Due to the springy properties of the chairs, they become more comfortable; you can quickly sit down and stand up without fear that this will cause back problems.
The system allows the chair to rotate 360 degrees . Thanks to this, you can freely reach everything that is around at arm's length and turn to a colleague or any person if necessary. The special mechanism is made so that you can spin around its own axis in any direction without any restrictions.

The gas lift allows the chair to rotate freely in any direction without any manipulation on your part.

In fact, this is a special hydraulic cylinder that is designed specifically for office chairs and is adapted specifically to the functions that are needed in this type of furniture. I will discuss the device and other important points below.

The most common breakdowns of office chairs

Damage to the cross

The main damage to this element is a breakdown at the junction of the beams. It is important to consider the material it is made of. The base is a hollow structure, inside of which you can place a polypropylene pipe of suitable cross-section and dimensions. The pipe is rigidly fixed to the damaged beam and base.

Note! You cannot splice plastic elements using a soldering iron or glue due to the high load on the paws.

The best option is to replace the plastic structure with a base made of glass-filled polyamide.

Disassembling an office chair is not difficult.

Dismantling the cross is carried out as follows:

Removing rollers. Usually they are not rigidly secured.
Dismantling the piastres. The fastening to the seat is carried out “on a cone”. It is necessary to disconnect the piastrum from the pneumatic cartridge by tapping at the attachment point.
Removing the retaining clip. It is located in the recess of the upper segment of the gas lift.
Knocking out the gas lift. If the damage is serious enough, this will not work. In this case, the working cylinder is removed along with the bearing and seal.

The convenience and ease of setting up office furniture directly affects the work efficiency of those who use this furniture.

Destruction of the swing mechanism

If it breaks, the chair stops holding the “horizon”. Dismantling this element is quite simple:

Unscrew the four mounting screws.
Knock the air cartridge out of the mount.

During movement, a proportional unloading of the entire spine occurs along its length.

The preferred solution to the problem is to completely replace the part. You can use a welding machine to repair an old mechanism.

Note! Russian and Chinese standard mechanisms differ in size.

Gas lift failure

If the integrity of the pneumatic cartridge elements is damaged, the rod does not extend when pressed. In this case, a complete replacement of the entire mechanism is necessary. It cannot be disassembled due to gas pressure.

Also, quite often the cause of breakdown is the bending of the adjustment lever, which just needs to be bent and returned to its original state.

Gas lift breakdowns occur for several reasons.

The design of a computer chair is quite complex, and at the same time extremely thoughtful. This ensures maximum comfort during use and allows you to work for a long time in a sitting position.

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Installation technology

How to install a gas lift system on a cabinet? Before installation you must:

determine the method of fastening the fittings;
prepare tools to do the job;
familiarize yourself with the diagram for attaching the lift to the cabinet door.

Mounting methods

The gas lift can be installed on a furniture cabinet:

using fixing pads secured with self-tapping screws. This option is easy to install, but can only be used for products made of wood, chipboard, MDF and analogues;
using screws with a locking function. The primary area of use is metal and plastic surfaces.

Types of fasteners

As a rule, self-installation of a furniture lift is carried out on plates, since the installation of screws must be carried out at the furniture manufacturing stage.

Tools and materials

To perform installation work you will need to prepare the following kit:

tape measure, square, marker (pencil) for applying preliminary markings;
drill for preparing holes for fastenings;
screwdriver and screwdriver for fixing the lift.

A gas lift is exclusively an additional device that facilitates the process of using a cabinet or other piece of furniture. The main fittings of a cabinet door are furniture hinges.

Even after installing the gas lift, the main load is taken by the hinges

Selection rules

There are a huge number of modifications of office chairs, so the gas lift for them is selected individually. It is recommended to consider three factors:

The class determines the thickness of the cylinder wall and the ability to support a certain mass of a person for a specified period of operation. On average, chairs are designed for a load of 80 to 200 kg.
Gas spring sizes vary. An important parameter is the diameter of the glass body, which in most cases is 50 mm. The length depends on the height adjustment range of the office chair.
The manufacturer plays an important role. The service life largely depends on the quality of the manufactured product.

What is a multiblock in an office chair?

The multiblock is a multifunctional mechanism installed on premium chairs. It allows you to customize the design point-by-point, according to your parameters and preferences. Withstands loads up to 120 kg.

You can assemble your own office chair.

Has the following functions:

seat height adjustment;
fixing the tilt angle in the range from 0° to 135°;
activation and blocking of swinging;
hardness adjustment;
Anti-shock effect that smoothly returns the chair to the working position.

If you buy an office product, the package should include fasteners and keys for assembly.
The operation of the multiblock is controlled through a system of handles located under the seat.

How to buy a quality product?

One of the selection parameters is the working length. It should allow the chair to be lowered or raised to the required amount. In some cases, the lifting height is purposefully limited. The simplest designs work on the principle of increasing resistance when raising/lowering, making movement smoother. Modern models have already introduced automatic systems. Work on the production of gas lifts is carried out on modern equipment using exclusively high-quality materials. Although some manufacturers seriously save on components.

Is it worth saving and purchasing a cheap gas lift? What troubles could this entail? Smooth movement and silent operation of the rod is ensured by high-quality processing of the cylinder surfaces. This operation is very expensive. If the technological process becomes cheaper when operating a gas lift, there is a possibility that it will jam, and its operation itself will be accompanied by noise. The use of low-quality valves with a short service life leads to their weakening. They will lose their initial effort pretty quickly. The use of poor steel for the manufacture of the stem and body causes excessive wear on these elements. As a result, the shock absorber will begin to jam, and squeaks will be heard during its operation. The cheaper the seal, the faster it will begin to leak gas, completely rendering the device inoperable. Another common problem when using low-quality gas lift is the breakdown of the air regulator. This can be solved by replacing the entire mechanism with a more expensive one, specifically designed for office chairs. Quite often, a gas lift is a supporting or load-bearing element in an office chair that can bear heavy loads. If the mechanism fails, the user of the chair may be seriously injured.

Features of the design and its functioning

First, you will learn what the node in question is, and then I will talk about the principle of its operation. Everything is quite simple, and you can easily understand the topic by reading this short section.

Gas lift device

To help you understand what the mechanism is, consider the diagram below. It shows all the main components that are found in all products of this type.

This is what a pneumatic chuck looks like in cross section

If it seems to you that everything is very complicated and you cannot cope with the repair work, then do not rush to close the article and take the chair to a specialist. The fact is that when carrying out repairs, you do not have to disassemble the product; firstly, this is not necessary, and secondly, it is unsafe - the gas inside the system is under pressure and any violation of the integrity is fraught with danger to life and health.

The main design elements are:

Button. By pressing it, a valve opens and closes, which releases gas from one chamber to another, thereby raising or lowering the chair. This element is pressed using a special lever, which is most often located under the seat.
Gas valve . Keeps the system in the desired position and opens when it is necessary to change the seat height.
Various bushings and seals . Necessary for tightly connecting all elements and sealing cavities in which gas is located.
Internal, external cavity and bypass channel . Due to the movement of gas through these structural elements, the height is adjusted.
Lifting rod . It extends or, conversely, lowers into the body, depending on whether the height of the chair increases or decreases.

The rod is durable, since it bears the entire weight of the sitting person

Support bearing . It is located at the bottom and is responsible for the free rotation of the chair in both directions. This connection is simple and lasts a long time.

Construction device

The design of a gas lift for a computer or office chair includes the following elements:

Button. The part is located under the seat and serves to open and close the valve.
Gas valve. Opens when it is necessary to change the height of the seat, fixes the structure.
Bushings and seals. They serve to tightly connect parts and also provide sealing of containers.
External and internal cavities. Designed for gas passage.
Passageway. Needed for height adjustment.
Lifting rod. When the height of the chair increases or decreases, it protrudes from the body or hides back.
Support bearing. A simple device thanks to which the chair can rotate in the desired direction.

It is not recommended to disassemble gas lifts yourself; violating their integrity is dangerous for humans.

Principle of operation

The operating principle of a gas lift for office chairs is simple. A rod with a piston moves along a cylinder located in a body made of metal. There are two containers in the pipe, and between them there is a valve. It can be in a closed or open position, when gas moves from one cavity to another along the passage channel. When the seat is positioned at the bottom, the piston is located at the top. When the lever is pressed, gas moves from one container to another. In this case, the piston moves down and the structure rises.

To fix the seat at the required height, the lever is lowered, the valve closes, and the lifting of the chair stops. To lower, the lever is pressed, and the structure begins to lower under the weight of a person. The gas piston allows the chair to be adjusted in height and rotated around its own axis. A special spring significantly reduces the load on the spine during a sharp landing, thereby preventing many diseases.

Computer chair gas lift device

A gas lift is a housing with a cylinder in which a rod and piston are located that have free movement. The cylinder is made up of a pair of reservoirs separated by an opening valve. When the chair is in the lower position, the piston is located in the upper segment of the cylinder.

In case of critical damage or destruction, it is impossible to knock the gas elevator out of the base.

When you press the lever to raise the chair, you press on a button that opens the valve, which causes gas to flow from the first reservoir to the second. This gas puts pressure on the piston, causing it to lower smoothly, causing the chair to rise.

A gas lift for an office chair is a type of spring in which gas acts as an elastic element.

When the pressure on the lever stops, the valve closes and the position of the piston is fixed. When the lever is pressed and a person is in the chair, the valve opens and the weight acts on the cylinder, which moves down. At the same time, the piston pushes out the gas, rising upward, which leads to the lowering of the chair.

Features of repair work

You can repair a chair yourself if you know all the nuances of the work process and have all the necessary equipment at hand.

Causes of breakdowns

First of all, I will tell you about the causes of problems so that you can prevent breakdowns whenever possible:

Manufacturing defects . It doesn’t happen very often, but nevertheless such situations arise from time to time, especially in the budget segment. If the warranty period has not expired, they will fix the breakdown, but if more time has passed, you will have to carry out the repairs yourself.
Overloading of the structure . If the chair is designed for one weight, and a person with a larger weight sits on it, then the wear of the elements occurs much more, plus the likelihood of breaking the gas cartridge increases significantly. Another common situation is when two people often sit on a chair.

The documentation always contains information about the weight the structure is designed for. Most often this is 100 kg, there are reinforced systems for 120 and 150 kg, they are more expensive, but also more reliable.

Incorrect operation . If someone sits down on the chair or suddenly lowers itself onto the seat, the gas lift is overloaded and the valve can simply be squeezed out, which leads to breakdown.

Types and sizes

There are different types of gas lifts, which is why in order to select the right option you should know the different models of mechanisms and what is special about them. Usually they are all made from the highest quality steel. Typically, gas lifts are divided into classes depending on thickness. There are 4 of them in total.

A feature of the models that belong to the first is that the thickness of the steel here is only 1.2 millimeters. These are the cheapest devices;
In the second group, the steel thickness will be slightly larger - 1.5 millimeters;
The third group will already have a steel thickness of 2 millimeters. Such gas lifts can withstand loads of up to 120 kilograms.
The last group consists of the most durable devices, where the steel thickness is 2.5 millimeters. Such a reinforced gas lift can withstand 30 kilograms more than models from the third group.

In addition, the devices in question may differ in case diameter. They can be of 2 types.

38 millimeters. This option is not used very often. It is usually used in executive chairs where the crosspiece is too high
50 millimeters. Used in 90% of chairs.

Another important parameter will be the length of the mechanism in question. The range of height settings will depend on it.

There are the following groups of gas lifts according to this criterion.

From 20.5 to 28 centimeters. This version will be used in relatively affordable office products designed for sitting at desks with standard characteristics. Such a gas lift will be short due to the fact that its adjustment range is extremely small.
From 245 to 310 millimeters. Such gas lifts are used in places where the structure must rise higher. Although the length of the device is longer, the adjustment range here will be even smaller than that of the above-mentioned analogue.
From 290 to 415 millimeters. These are the longest mechanisms that have wide possibilities in terms of height adjustment, which makes it possible to greatly change the position.

These groups of gas lifts are considered the main ones, although other models can be found on the market. For example, 180 mm. But they are used quite infrequently, which is why they are more of an exception to the rule.

Tips for choosing

Gas lifts for office chairs, like all devices, can fail over time, but you can repair them yourself. Breakdowns are usually caused by:

Manufacturing defects. The phenomenon is rare, but sometimes occurs, especially in budget products. If the warranty period has expired, the repairs are carried out independently.
Gas lift overload. There are situations when a structure designed for one weight is used by a heavier person or two people sit on it. Then the parts of the mechanism wear out much faster and more severely.
Incorrect operation. Damage occurs if you sit down suddenly or take a running start. The device is overloaded, which can lead to the valve being squeezed out.

The documents included in the package contain information about the maximum permissible user weight. Basically, this is 100 kg, but more expensive and reliable devices are produced, which are designed for 120 and 150 kg.

If the gas lift for an office chair breaks down, it is not enough to repair it; it is important to choose the right new design. The correct choice is very important, since discrepancies in parameters will again lead to rapid wear. The following points should be taken into account:

Product dimensions. The structures are manufactured with different dimensions, so the gas lift is selected in accordance with them.
Cup holder diameter. It comes in two types, so choosing the right option is easy.
Gas lift height. It is necessary to measure the length of the product, taking into account the fact that part of it is located inside the cross.
Maximum load. The product class should be selected depending on the weight expected during operation. Moreover, the fact that other people can use the chair is also taken into account. If a piece of furniture is at home, then most likely all family members will sit on it.

Gas lift plays a very important role in office and computer furniture. The chair is designed in such a way that the spine does not get tired when sitting for a long time. The mechanism makes it easier to work in the office and makes staying at your home computer more comfortable.

Product dimensions

Maximum load

How to choose

Considering that there are different categories of gas lifts, and this is a part that fails from time to time, it would not be superfluous to consider the question of how to choose the right gas lift. To begin with, it should be said that the cause of breakdowns of gas lifts, due to which they have to be replaced, are the following points.

Manufacturing defects. This problem is rather an exception, but still occurs, especially in the most accessible versions.
Gas lift overload. It happens that a design that is intended for one mass is used by people whose weight exceeds this indicator, which is why the wear of the components occurs at an accelerated pace.
Incorrect use. It happens that a furniture or any other gas lift may fail due to the fact that a person suddenly sits down in a chair or even does it with a running start. Using the chair this way can result in the valve simply being squeezed out.

In such cases, replacement of the gas lift is required. But to implement it, you need to choose it correctly. This is extremely important, because discrepancies in certain characteristics can lead to accelerated wear of the new device and its subsequent breakdown. To prevent this from happening, you should make a choice based on such moments.

Cup holder diameter. It can be of 2 types, so using this criterion it will be easy to determine the desired option.
Gas lift height. In this case, it is necessary to measure the length, taking into account that the part will be located inside the cross.
Product dimensions. Note that gas lifts are made with different dimensions, so the size must be taken into account when choosing.
Maximum load. It is necessary to select the class of the mechanism depending on the mass that it will have to withstand during use. Moreover, it should be taken into account that the chair can also be used by other people.

Criterias of choice

When choosing a furniture gas lift, you should take into account the two most important parameters: the compression force and the dimensions of the door where the device will be attached. To hold 1 kg of load, you will need a force of 10 Newton. Once you know the mass of the door, you can determine the required size. Most manufacturers create devices with a load of 50–150 Newton. In addition to weight, the size of the door is very important. The maximum length of the furniture gas lift depends on this. The larger the spring required, the wider the housing required.

The use of step-by-step or automatic door designs depends on the gas lift. The first is distinguished by the presence of handles on the facade. The second implies that the sash will open when the button is activated, and then after a certain period of time will automatically close. To achieve this effect, an electric drive is built into the furniture. The devices are ideal for people who forget to close cabinet doors behind them.

How to change

As was said, if a gas lift breaks down, it is almost impossible to repair it, which means it needs to be replaced. To do this, you first need to prepare certain tools and understand the algorithm of actions. You will need to have the following things on hand:

a new gas lift, which will be installed instead of the old one;
crosshead screwdriver;
hammer;
ring punch;
WD-40 liquid;
vice.

So, before replacing the gas lift with a new one, you need to remove the old one.

To do this, we treat the joints of the chair parts with WD-40 liquid . We leave the structure in this state for about 12 hours so that the mixture gets onto the joints. Now you need to start disassembling the chair and disconnect the seat. To do this you need a Phillips screwdriver. With its help, we loosen the bolts that secure the seat to the piastre. After this, we turn the chair over and remove the seat along with the decorative cover, which is located on the lift.

Now you need to disconnect the lift from the cross and piastres. This can be done by knocking out the gas lift with a hammer with a rubber tip. To speed up this process, you can use a drift. Before starting work, remove the special locking ring from the crosspiece. This is a pin, which is located on the back side of the cross where the pneumatic cartridge is attached.

Now you should remove the pneumatic cartridge from the piastrum. This work should be done as carefully as possible so as not to deform the connections. Tapping with a hammer should be done in different places so that the gas lift can be carefully removed.

You just need to install a new gas cartridge.

First, we insert it into the cross until it clicks, applying some force, and put on the protective casing, after which we connect everything to the piastr. All that remains is to reassemble the chair in the reverse order.

The video below talks about how to choose the right gas lift for a chair.

Operating principle of gas furniture elevators

Lifts consist of working chambers (cylinders), friction bearings and oil seals. All these parts create the conditions for hermetically sealed movement of the rod throughout the device. The piston sleeve and bypass valve protect the lift from distortion, and the springs act as dampers.

When opening the fronts upwards:

When the front is closed, the piston rod is recessed in the working area. This is possible thanks to the compressed gas contained in it. When the door opens, the gas pushes the piston in the opposite direction. An oil damper is responsible for smooth running. At the end of the closing cycle, the oil flows, creating a shock absorber effect.

Many people have a question: how does an open door stay in the air on its own? This is possible due to the fact that the device is not equipped with an oil damper. Thus, the facade itself is fixed in any position; there is no need to hold the door.

When opening the fronts down:

Shock absorbers for kitchen cabinets that open downwards have a similar structure. But there is also a difference. They differ in that it is necessary to apply more force when opening the door. This is due, first of all, to the fact that the bypass valves have different diameters. Therefore, oil and air flow through holes of different sizes with great force.

Design and principle of operation

If we talk about the structure of the part in question, then it should be said that the main parts of this design are such elements.

Button. By pressing it, the valve closes and opens, which releases gas from one chamber to another, which allows you to adjust the height of the entire structure. Pressing occurs using a lever located under the seat of the chair. Although sometimes it may be located in a different place.

Lift rod. This part extends or lowers into the body, depending on the increase or decrease in the height of the chair. By the way, this part is especially durable, because the mass of a sitting person puts the greatest pressure on him.

Various types of seals and bushings. They are needed for high-quality connection of various parts and sealing cavities where gas is usually located.

Gas valve. This part holds the entire mechanism in a certain position and opens if the seat height level needs to be changed.

External and internal cavities, as well as a bypass channel. Thanks to the movement of gas through these parts of the mechanism, height regulation occurs.

Support type bearing. It is located below and is responsible for the free rotation of the chair in different directions. The strength of this type of connection is its simplicity, which ensures its durability.

If we talk about the principle of gas lift operation, then it cannot be called complicated. To begin with, the mechanism consists of a pair of reservoirs and a valve that can open and close. It is his work that causes the gas to move through the bypass channel between the containers. If the chair is in the lower position, the piston will be in the maximum raised position. When you press the lever, the valve opens, the gas begins to move into another tank and thereby presses the piston, which moves down and raises the chair.

Once the chair is at the desired level, you simply release the lever to lock it. The valve will close immediately and the chair will be in the desired position. If you need to lower the chair, you just need to press the lever, after which it will lower under the weight of the person. That is, to raise the chair, you need to stand up from it. As you can see, the operating principle of a gas lift is extremely simple.

Types of mechanisms and their operating principles

There are quite a lot of mechanisms for office chairs, but the most common are the following:

Piastra. This spring-screw mechanism allows you to adjust only the height of the chair. It is a block with a gas lift control lever, which provides height changes.
Permanent contact. The most common mechanism that ensures the backrest is fixed and tilted at an angle of up to 128°, which allows you to relax your back. Also responsible for adjusting the rigidity and depth of the seat.
Rocking mechanism. Makes it possible to use a design similar to a rocking chair, with the range of seat and backrest deflection ranging from 95° to 135°. The swing axis can be located in the central part or be shifted forward.

A piastra is a block with a lever that controls the position of the gas lift.
Note! Chairs with a rocking mechanism are not recommended for people whose weight exceeds 100 kg, as the welded bushing used may break under high loads.
Anti-shock effect. This mechanism allows you to smoothly return the chair to its working position after swinging. To do this, first the rocking mode is blocked, and then the backrest is pressed.
Synchro mechanism. It ensures free change of sitting position, triggers the swing mechanism, supports the back and prevents tipping over. This is achieved by changing the angle of the seat simultaneously with the tilt of the backrest.
Note! The most comfortable proportion of changes is 1 to 3, that is, the seat deviates by one degree when the backrest deviates by three degrees.

If the chair does not hold the “horizon”, then the problem is most likely in the destruction of the swing mechanism.
Asynchronous mechanism. Allows you to change the angle of the backrest without reference to the position of the seat.
Slider. Allows you to adjust the depth of the seat, which extends forward with the ability to be fixed in various positions.

An asynchronous mechanism, unlike a synchronous one, makes it possible to change the tilt of the backrest without affecting the position of the seat.

Varieties

Gas lifts for chairs are divided into types depending on the size of the structure and the strength of the steel. Before choosing a suitable modification for a computer or office chair, you should study all the nuances. The first thing you need to pay attention to is the device class, which indicates the thickness of the steel and the permissible load:

The first is budget fittings, the metal thickness is only 1.2 mm, such a gas lift is suitable for children's models.
The second one also belongs to the inexpensive segment, the steel thickness is 1.5 mm and will not withstand heavy loads.
The third is a type of gas lift with a metal thickness of 2 mm, maximum load 120 kg.
The fourth is a reinforced case with a metal thickness of 2.5 mm, permissible weight 150 kg.

Characteristics of fashionable glider chairs, advantages of their use

In addition to classes, gas lifts differ in body diameter. Existing sizes:

50 mm - used in almost all models.
38 mm is a rare diameter; such gas lifts are mainly installed on executive chairs with a high cross.

Another important parameter is the length of the gas lift. This indicator determines the maximum seat height:

20.5–28 cm. The device is designed for chairs that are used in offices with standard desks or computer desks. This gas elevator has a relatively small range of height settings.
24.5–31 cm. Used when you need to raise the chair more than the standard height.
29–41.5 cm. The longest gas lift with wide height adjustment options.

When a gas lift breaks, the user is faced with the question of how to choose a new mechanism and what to pay attention to. Even a minimal discrepancy in characteristics can lead to rapid wear of a new part, so when purchasing you need to consider the following points:

Gas lift size - mechanisms can have different dimensions. You need to make sure that the part will fit correctly into the base of the chair.
Cup holder size - there are only two diameter sizes, so choosing the right one will not be difficult.
Height - it is necessary to measure the length of the old part, taking into account that part of the gas lift is inside the cross.

The procedure for making a rocking chair from different materials with your own hands

You also need to pay attention to the load. The class of the mechanism is selected depending on the body weight of the owner of the chair. If the furniture is used at home, most likely, the entire household will sit on the chair. For office furniture, it is better to choose a gas lift with a maximum load.