CFMR-NC Spring hinges Automatic return on closing

Rotation angle (approximate value)

Max 270° (-90° and +180° being 0° the condition where the two interconnected surfaces are on the same plane).

The hinge can reach -90 ° but this condition must not be used for CFMR-NO execution.

Do not exceed the rotation limit angle so as not to prejudice the correct operation of the return spring.

Features and performances

CFMR hinge is used for the automatic re-closing or re-opening of the door by the return spring.

The torque varies progressively with the opening/closing angle of the hinge.

In specific fatigue stress tests, the return spring exceeded 100,000 cycles while maintaining the same unaltered torque values.

 

Resistance tests	AXIAL STRESS	RADIAL STRESS	90° ANGLED STRESS
Description	Max limit static load Sa [N]	Max limit static load Sr [N]	Max limit static load S90 [N]
CFMR.	2100	3500	1900

The max static load is the value above which the material may break thus prejudicing the hinge functionality. Obviously, a suitable factor, according to the importance and the safety level of the specific application must be applied to this value.

Selection guide

The return force of a door that has a certain weight W (Kg) depends on the spring force of the hinge [Nm] and of the friction between the sliding surfaces between the fixed part and the movable part of the hinge which in turn depend on the tribological properties of the technopolymer used.

The table provides a rough guide for choosing the hinge and its positioning for a specific application.

These values are the result of tests carried out in a laboratory under controlled temperature and humidity (23°C-50% R.H.), under determined conditions of use and for a limited period of time.

It is recommended to always check the correct operation for the intended application.

For further general technical information, consult the Guidelines

 

Pmax= maximum weight of the door that the hinge is able to close with a small residual holding torque tested at a minimum opening angle of 45°.

NOTE: this weight depends not only on the geometry of the door (in particular on its centre of gravity) but also on the perfect coaxiality of the hinges.