In What Applications Can Variable Force Springs Be Used?

Variable force springs and variable torque springs can be combined in one spring with negative gradients and positive gradients. It breaks through the influence of Hooke's law on traditional springs, so that the stroke and force no longer increase proportionally, but are accompanied by various elastic force-displacement combinations, such as negative slopes. In this way, step-by-step constant force can be achieved. Here we give some examples to illustrate the relationship between load (force or torque) and stroke, which can be used in specific occasions for engineering reference.

Pen injector application

The spring applies a constant force to keep the drug flow fixed and prevent patients from feeling uncomfortable when using it. It has a tensile force at the end of the stroke to ensure that all drugs can be fully injected.

Fireplace up and down sliding door

Variable force springs can also be applied to up and down sliding doors in fire places.

When the door is closed, the spring force is less than the weight of the door; when the door is in the middle of the stroke, the spring force is equal to the weight of the door. When fully opened, the force applied by the spring is greater than the weight of the door to ensure that the door does not slip off.

Point of purchase display

Variable force springs can be applied to point of purchase display. The spring outputs a variable force to match the number of items displayed. Large force can ensure smooth pushing of large display items, and small force can effectively push small mass items to avoid the display items being crushed.

Cordless curtains

Variable torque springs can be applied to cordless curtains, allowing users to easily adjust the curtains up and down. The spring gradually applies smaller torques, creating a gravity balance that allows the curtains to stop at any height.