Cordless Blind Mechanism

The mechanism problem

The load seen by the spring may change as the blind moves. Roll geometry, cord routing, moving components and friction influence the output required at the spring connection. A requirement for smooth movement is useful only when the relevant positions and forces are described.

We supply the spring component for these mechanisms. Include any complete-system safety or compliance requirements when you describe the application.

Define the force or torque profile

Provide the blind type and mechanism layout, total travel and moving load. State the desired force at defined linear positions, or torque at defined angles where the spring drives a shaft. Show the connection between the spring and the moving blind.

Choose the required output profile

For a pull that changes with extension, start with variable force springs. Where the required pull is approximately steady, compare constant force springs. A rotational requirement should be described with torque and working turns so the construction can be reviewed.

Prepare these inputs

• Blind type, moving dimensions and load through the travel.
• Full mechanism layout, transmission ratio or winding geometry where applicable.
• Force-versus-position or torque-versus-angle targets, with units.
• Available spring space, mounting details, attachments and working direction.
• Installed preload, travel limits and any separate holding mechanism.
• Operating environment, cycle target and requested quantities.

Start with the information available

PDF, DWG, DXF and STEP drawings can be reviewed. If no drawing exists, provide photos or a sample with the installation space and operating requirements. The sample helps establish geometry; the requested output still needs to be defined.