In spring Auto BLOCK, literally according to it’s name, a slight cushioning effect or damping effect is provided during compression as well as extension. This is to avoid a sudden blocking or rigidity in the application in both directions. The most common application is the back rest of a passenger bus seat.
This is a unique Auto BLOCK in the way that, the gas spring can be locked against compression, but under free condition, it extends completely. It stays in place only under external load. A common application for this gas spring is the over bed ‘Food Trolley’ used for feeding patients. In this, the “external load” is the food plate which counter balances the gas force in the gas spring.