Constant Force Spring Manufacturer
Power Spring
January 25, 2022
Custom Spring Manufacturers
Stainless Steel Spring
July 21, 2022

Variable Force Spring

Highly Engineered Variable Force Springs

In a variable force spring, negative and positive gradients can compound. It overcomes the impact of the typical spring, which is influenced by Hooke’s law so that the stroke and pressure are no longer correspondingly increased.

Instead, they increase in conjunction with alternative elastic pressure combinations, such as negative slope. As a result, it is possible to achieve a stepped constant force.

We can design and produce custom variable force springs and fitting for your product display application in addition to our regular end fittings.

Variable Force Springs Characteristics

  • Variable Force Springs are ideal for applications where a higher initial force is essential to move the product.
  • The variable force spring immediately adjusts to the lighter load when the product is removed, resulting in a smooth product transition.
  • They are likewise cost-effective, simple to assemble, and take up little space, just like the constant force springs.

Engineering Techniques

Here are some instances of load and stroke relationships that we utilize as engineering references on special occasions.

Application Of A Drug Injector

The spring maintains a consistent force on the drug flow, ensuring that the patient is not uncomfortable while using it.

Display At The Point Of Sale

A variable-force spring is useful in a point-of-sale display. To fit the number of display items, adjust the spring export variable force.

Slide Door In The Fireplace

The up-and-down sliding door of a fireplace can fit with a variable force spring. The spring force is smaller than the weight of the door when it is closed.

Cordless Shades

The cordless shade can benefit from a variable torque spring, which allows the user to simply adjust the curtain up and down.

The power spring is coiled by a steel strip. A spring box is required to limit its outer diameter. The center of the spring is connected to the shaft. When an external force is applied to make the shaft and the spring rotates relative to each other, the spring will be wound on the shaft and stored Torsion, when the external force disappears, the spring generates torsion on the shaft or spring box.


Variable force spring and variable torque spring are very similar to constant force spring and constant torque spring. Variable force springs and variable torsion springs can break through the influence of Hooke’s law on traditional springs, so that stroke and force no longer increase proportionally, but can achieve various elastic force-displacement combinations such as negative slope stepped constant force, which can be mechanically controlled. For engineering requirements, use the relationship between elastic force and displacement stroke to design various elastic curve changes in specific applications. There are many different variable force springs designed available for any given application to meet customized solutions.


Power springs are divided into natural power springs and pre-stressed power springs according to their relaxed shape. In contrast, the pre-force type power spring can store 25% to 55% more torque and provide more effective turns.


Function+ Applications:

The spring exerts constant force to keep the drug flow fixed, preventing the patient from feeling uncomfortable when applying it. It features stretch force at the end of the stroke to ensure all drugs can be injected entirely.


Variable Force Spring

Point of Purchase Display


Variable force spring can be applied to point of purchase display. The spring export variable force to match the number of display items. While the large force can ensure pushing large quantity display item smooth, the small force pushes small quality items availably and avoid flattening the display items.

A variable force spring can be applied to the up-down slide door of the fireplace. When the door is closed, the spring force is less than the weight of the door; while the door in the middle stroke, the spring force is equal to the door weight. When fully open, the spring exerts force greater than the door weight to secure the door does not slide down.


Variable Force Spring

Cordless Shades


The variable torque spring can be applied to cordless shade, it makes the user adjust the curtain up and down easily. The spring exerts smaller torque step by step, which generate a balance of gravity to allow the curtain to stop at any height.