Gas Springs differ from most other types of springs we produce here at European Springs because they already have a built in pre tensional force with a flat spring characteristic. This enables the spring to only have a minor difference in force between full extension and full compression.
The piston and rod are pressed into the cylinder, which reduces the volume whilst pressure increases. This causes pushing forces to increase and in conventional gas springs, this increase is normally around 30% at full compression.
The [diagram] illustrates, in simple terms, forces F3, F4, F2 and F1 along the stroke when the gas spring is fully compressed and then released. F1 indicates the force just before full extension. It is this static F1 force we refer to when we talk about the force of a gas spring. The difference between force pairs F3/F1 and F4/F2 varies according to the amount of friction.
The pushing spring movement is slow and controlled as it is reliant on the gas flow between the piston sides being allowed to pass through channels in the piston during the stroke. Conventional gas springs use 'hydraulic damping', which involves a small amount of oil slowing down the speed of the stroke immediately before the spring reaches full extension. This gives the movement a braking character at the end position provided that the piston
rod is in the downward direction, making conventional gas springs ideal for many uses and applications.