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The piston is pushed forward by the gas.

It is designed to set and regulate the speed of the rod exit.

Application example: Lowering, tilting and damping of sashes.

 

Detailed operation:

The compression gas spring consists of a cylindrical, watertight body called theÌýTubeÌýand a steelÌýRodÌýat the end of which is mounted aÌýPiston, which performs cycles of compression and expansion inside the tube. TheÌýTubeÌýcontains pressurizedÌýNitrogenÌýand a small quantity ofÌýOil.

During the compression phase, theÌýGasÌýflows from the right to the left side of theÌýPistonÌýthrough theÌýPiston Orifices. At this point, the pressure inside theÌýTubeÌýrises, generating an increase in force.

The flow ofÌýGasÌýcan be modulated by adjusting the diameter of theÌýOrifices, in order to regulate the speed at which theÌýRodÌýleaves the cylinder.

The rate of progression (also known as stiffness) can be modified by acting on the diameters of theÌýRod/BodyÌýpair and on the quantity ofÌýOilÌý(see force diagram below).

 

 

Determination of a FORCE: Force = Pressure x Surface (DaN) Ìý (bars) (cm2 of piston) (1 DaN = 10N) (P Max 160 bars)	Mariotte’s law: Pressure x Volume = constant (with CONSTANT temperature) P in Pascal (100 000 Pascal = 1 bars) V in M3
Ìý
Volume increases therefore pressure and force decreases Ìý Ìý Ìý	Volume decreases therefore pressure and force increases ÌýÌý

 

The piston is pushed forward by the gas.

It is designed to set and regulate the speed of the rod exit.

The cushioned cylinders include an oil charge of 65% of the internal volume. These gas springs cushion the rod extension at a speed of around 0.1 m/s. Rod retraction is free.ÌýCaution: inflation force is greatly reduced.

The piston moves toward the bottom of the cylinder under the effect of pressurized nitrogen.

This results in a pulling motion on the rod.

Application example: Lifting a hatch by pulling on it instead of pushing it.

Please note that the more information you have, the more accurate and therefore efficient the gas spring will be.

First of all, it is necessary to know the environment in which the gas springs will evolve : temperature, dust, aggressive environment, food etc..

The dimensions of the moving part (RH and LH) and the Weight to be lifted should be taken into account when choosing the diameter of the gas spring rod and the type of end fitting (environment, frequency of use, operator etc.).

Case study with Fig. 1 • Application type: Floor hatch – Ground level trapdoor (Most common) • To open a door with a 90° opening angle, the following rule must be observed:ÌýStroke = 1/3 of RH Exemple: • RH = 950mm, LH = 1500mm, Weight = 30Kg, Opening angle = 90°, No of gas springs • Stroke: 950:3= 316mm => see our catalogue to choose the closest stroke = in this case : 300mm • We can use the reference: ST 300 +F1+ D10   Fixing Important: All the dimensions are taken from the axis of rotation • Ìý Ìý Ìý On the frame: The dimensionÌýY1Ìýwill be less than the stroke,ÌýX1Ìýwill give the gas spring the necessary angle to the lever arm to start the movement, an ideal position will give an angle of 15° to 25° to the gas spring when the door is closed.       On the opening The dimensionÌýX2Ìýwill be defined by the extended length of the gas spring and the maximal opening angle. Y2Ìýwill take into account the thickness of the door as well as the type of fixing bracket chosen. In this example:ÌýX2Ìý= 497mm,ÌýY2Ìý= 20mm If all the parameters are accurate, the hatch should be closed with is own weight.

Dimensions in mm

 

Force calculation

To calculate theÌýforce F1Ìýof a gas spring in these two cases, the following formula should be applied:

• N= No of gas springs,ÌýRH= in metres,Ìým= Weight in Kg,ÌýX2= in metres Ìý5*= Friction force

Adjust the force at upper tolerance:

F1 = Ìý Ìý 30 < N < Ìý Ìý 50 Ìý Ìý ÌýAdd Ìý Ìý +0N

F1 = Ìý Ìý 50 < N < Ìý 250 Ìý Ìý ÌýAdd Ìý +20N

F1 = Ìý 250 < N < Ìý 750 Ìý Ìý Add Ìý +30N

F1 = Ìý 750 < N < 1500 Ìý Ìý Add Ìý +60N

F1 = 1500 < N < 3000 Ìý Ìý Add +150N

F1 = 3000 < N < 6000 Ìý Ìý Add +300N

 

Browse our gas spring catalog and request a quote today!

 

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