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Types of Springs: Extension and Drawbar Springs


Types of Springs: Extension and Drawbar Springs


Extension springs

Extension springs are those that perform a stretching function and perceive the longitudinal-axial load, which stretches the entire spring. When the load is removed, the spring assumes the initial position. The longitudinal-axial load is directed to extension springs, due to which these springs are stretched. You should know that Custom Spring Corporation extension springs can be used to connect all kinds of unstable structures, where due to its characteristics, it does not allow structural parts to get damaged.

Extension springs can be of cylindrical, conical and barrel-like shapes. Extension springs are made, as a rule, from a wire with a diameter of 1.0-16.0 mm and, more rarely, with a diameter of more than 16.00 mm. Extension springs with a wire diameter of 19-20.0 mm are manufactured for pantographs of electric locomotives and for agricultural transport.

Prices for extension springs depend on the following parameters:

– Product configuration;
– Number of springs ordered;
– Material used;
– Urgency of manufacture.

Drawbar springs

Drawbar springs represent constructions in which the spring can compress as the drawbar arms extend due to an applied load to them. They are usually capable of withstanding loads far in excess of the extension spring closing force and should be considered in applications wherever a positive stop or overload protection is needed.

A drawbar spring has many of equivalent properties that an extension spring has, but is made as a compression spring with interlocking bars inside it connected to each end. Such a construction prevents from over-traveling even under some extreme conditions.

A common issue with extension springs is the chance of over-traveling, that refers to a spring being stretched beyond its capabilities and being unable to perform anymore. In drawbar springs, their bars hook on opposite sides so when the bars are fully stretched, these springs remain solid and cannot stretch anymore. This construction is also useful in preventing buckling of the spring throughout compression.

The drawbar can be made of any grade of wire, as they’re quite robust if they are manufactured with an equivalent diameter of wire.

The drawbar ends should be closed, but not ground. Many sizes of springs have been made in this manner. One of the features is that such springs have a fixed position when the spring goes solid thus eliminating the possibility of overstretching. Another good feature of the drawbar is the elimination of buckling. The drawbar should be greased during operation to reduce friction. Drawbar springs are great when it comes to dealing with potential overload situations and offer a built-in safety feature that will continue to carry a static load even upon fracturing.

One of the features is that such springs have a fixed stop when the spring goes solid, and thus overstretching is eliminated. One more advantageous feature of drawbar springs is the elimination of buckling. It is necessary to lubricate them during operation in order to reduce friction.

We hope you find this article helpful and you gained some insights into extension and drawbar springs.


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