CONSTANT FORCE SPRINGS/Constant Torque Springs-A type

TSMC 'S Constant Torque Springs are constructed from a pre-stressed flat strip material in a tightly wound spiral and placed on two drums. A constant torque load is developed when the spring's outer end is attached to another drum as the spring is reverse flexed from the output drum and will returns to its natural curvature on the storage drum.

As its name implies, these Constant torque spring exerts a nearly constant restraining force to resist uncoiling, while offering a large torque in relatively small space requirements. With these characteristics, the constant torque is ideal for a particular area of application with the use of cable, pulley requiring smooth returning, retrieving and counterbalancing, most commonly used for wind-up motors, feeders and conveyors, counterbalance which are utilized in the Aerospace, Medical Devices, Window, Automotive industries etc.

FEATURES

Type A Characteristics:

Constant output torque (zero gradients).

Low output torque.

No intercoil friction (smooth operation, low hysteresis losses).

Low life.
(a) Maximum torque obtained at a life of 2,500 cycles.
(b) Life increases as the output drum increases.

a Large number of output turns.

Spring can operate as a clutch on output drum.

There are four critical factors when considering a Constant Force Spring design such as Bore/ shaft (ID/OD), Load, Working height at which the load is applied, and Material desired, as well as the other input parameters that contain the wire thickness, wire radial wall, active number of turns, work height, load at work height ... The input data, as shown on the left table. And calculation results with spring rate (stiffness), working load (±10%), outer diameter at solid height, Working curve and Life cycles prediction where found in the down table.