Look around you during a day and you will undoubtedly find a variety of gas struts or gas springs in use; these simple, clever and innovative devices come in a range of shapes and sizes and are widely used in the automotive industry. Open any hatchback and you will find it is supported by two gas struts that allow for the simple opening and closing of the hatch, and that support when it is open. It may be a simple operation, but it is also a very clever and useful one. Gas struts are not just used in cars, of course; they can be employed to ensure the smooth opening and closing of doors, for example, and are vital in many industrial machines.
Bonnet & Boot
More and more often it is found that car manufacturers – particularly those with high end models – are employing gas struts for both the bonnet and the boot; gone is the simple metal bar that was once commonplace in the front of the engine, and now there are smooth operating systems that are easy to use and very versatile. Furthermore, they are utilized in luxury vehicles to enable the opening and closing of automatic soft tops and hard tops, and do the job very well indeed. For the car industry the development of gas struts has been a major bonus.
Gas struts work in a simple fashion: the gas itself is inside a sealed tube with pistons at one or both ends; when the pistons are extended the gas is there to keep the strut at the desired length in operation, and to prevent it from falling back. Only on compression does the strut return to the compressed location, and then operate the mechanism for the door or other item to return to its original position. Over time gas struts can leak – everything is subject to wear and tear, after all – and it is no problem to have the re-gassed to extend their lifetime.
Hydraulic jacks are an extension of the gas strut concept, and provide excellent support and lifting capability. They come in a number of different styles, each with a specific purpose in mind.
Bottle jacks are widely used in industry for lifting items, and are shaped as a bottle style with a hydraulic piston on the top. This is raised by the hydraulic action and creates the lifting power required. This can be quite impressive, with bottle jacks offering capability from as little as two tons to over 100 tons.
Trolley jacks will be familiar with any car mechanic and are versatile and useful devices; they can be pushed under a vehicle as they are fitted with wheels, and the handle operated action is easy to use. The slow fall rate is provided in the same way as the gas strut works. Trolley jacks generally offer between one and three tons of lifting power.
Toe Jacks are excellent devices that have the advantage of great versatility and agility, and are similar to bottle jacks in their construction. They are used widely in industry for moving heavy machinery and other items, and are surprisingly affordable.
Using Jacks & Struts
Of course, it pays to be aware of the pitfalls when using any jacks or dealing with gas struts. Jacks are there to lift a vehicle or other item, but not necessarily to hold it. Once you have lifted your car – if that is the intention – you need to support it either with ramps or axle stands, and remove the jack. If left for too long a jack can gradually release its holding power, and older models may not have the capability they once had. For security and safety make sure anything that you have jacked up is securely supported.
Gas struts are versatile and useful items, particularly where we find them on cars, and it is possible to fit new struts yourself. It is a job for two people as the boot, hatch or bonnet will need to be held open, but in general it is done with just a screwdriver. There is plenty of information about the different gas struts, jacks and other hydraulic items available online, along with instructions and guides on how to fit a new set and how to use jacks safely.