The foundation of a rack arm louver system is provided by assembled rack arms. The louvers up-to-and including the 117-E make use of the S-system. Here above you see a drawing with the 96-E louver. The parts of the S-system rack arm are described here below.
An assembled S-system rack arm contains at least the following components::
- rack arm
- pivot arms
- slat clips
- operating strip
- bearing bracket
- link arm
These parts are located at the so called (operating) strip side of the rack arm.
The rack arms also carry the operation of a blind, which includes a gear work and a motor, or a crank. These parts are located at the other side of the rack arm – the motor side.
Rack arms are profiles manufactured from 6060 T66 grade aluminium. The standard rack arm, displayed above, is 35mm high and incorporates a track to accept the pivots and two nut slots to allow fixings. During pre-assembly, the rack arm is notched to ensure that the pivot are located in the correct position.
The pivot arms are located into the notches of the rack arm, this is a positive fix. Once inserted, they cannot be taken out. The slat clips, that hold the louver, are connected to the pivots. Pivots and slat clips, together referred to as clips, are made from (PA) polyamide or (PP) polypropylene. This is done in-house by injection moling.
The operating strip aluminium extrusion – is drilled to the same pitch and accuracy as the notching of the rack arm. If the pitch of the operating strip holes does not exactly match the pitch of the rack arm, then the system will not open and close correctly. The slat clips have extended lugs to which the operating strip is attached. The operating strip therefore attaches all the slat clips together and ensures that they move in a uniform manner.
The bearing bracket is attached to the underside of the rack arms – once again the position of this is critical to ensure the correct operation of the system. The rotating arm of the bearing bracket is then attached to the operating strip by means of the link arm. Once this has been done , the rotating of the bearing converts into a linear motion of the link arm and operating strip which turn converts into the rotational movement of the slat clips around the pivots allowing them to move from fully open to closed.
The bearing brackets can be placed anywhere along the rack-arm. Their position is defined by the required closing direction. The sketches below show the motor or gearbox position in relation with the closing direction for internal or external blinds.