The design of roller shutters consists of several key features, including an overhead roller barrel drum. This is supported by two load-bearing side plates or ‘cheek plates’ on either side of the opening. These side plates are secured to the building using adequate fixing methods in order to take the full load of the shutter.
Two guides or tracks run up either side of the curtain to keep it aligned and straight during movement. A manual or powered drive mechanism (see more below) will raise and lower the curtain. If powered by a motor, the motor will be fitted to the curtain’s overhead barrel assembly and will regulate the maximum travel distance of the curtain, as well as its speed. A motor will also be fitted with an operational brake to hold the curtain stationary when it is in it its upper-most position.
The curtain itself is generally made from interlocked laths of steel or aluminium. The bottom rail or the bottom section of the curtain, either in a ‘T’ or an ‘L’ shape, will be reinforced in order to provide additional rigidity to the curtain.
Operation
At Mercia Industrial Doors, we offer a selection of operation and actuation systems for our roller shutter doors. Operation can be manually or electrically controlled and may vary depending on the size of the door you have chosen. Most models and sizes, however, will be available with the following options:
- Push-pull: By far the most common means of manually operating a shutter is through pulling/pushing the curtain itself. The overhead barrel is spring loaded and the curtain is counterbalanced to accommodate the weight of the shutter as it rises and falls through the guides. Security is ensured through a centre-mounted lock which is activated by the user simply turning a key.
- Hand Chain Drive: Generally fitted to large galvanised shutter doors, a hand chain drive system makes opening the roller door relatively easy. A factor to be considered for this method of operation is that a chain drive is only suitable for internal installation, in order to prevent anyone from gaining unauthorised access to the chain.
- Single Phase Tubular Motor: Single phase roller shutter doors are often used in commercial applications, where the operation of the door will be limited to a certain number of times a day, such as shopfront entrances, doorways and windows. They can be operated by turn-key switches, rocker switches or remote-control hand-held transmitters.
- 3 Phase Motor Gearbox Drive: Ideal for heavier duty applications, 3 phase rolling shutter doors can also withstand more frequent operation, for example in loading bays, car park entrances, and goods in/out stores.
Other special industrial requirements can be discussed during the design process.
Actuation
To ensure the safety of employees and/or visitors near the roller shutter doors, we offer several actuation systems in order to calculate when to open the door and to prevent early closure.
- Induction loop: Induction loops are high performance single or dual channel vehicle detectors, designed to be compact and easily concealable in order to preserve your property’s aesthetic. Through electrical conductivity, induction loops detect a vehicle’s presence, which then signals the doors or barrier to operate and let them through. You can decide what sets off the signal, giving you control over what can enter your property.
- Radar Detection: Radar is perhaps the most suitable actuation system for industrial environments due to the different settings that can be employed through it. For example, it is possible to set a radar system to only detect vehicles or to only detect vehicles/pedestrians that are only headed towards it, rather than someone nearby or moving past it.
- Photocell: A sensor unit is fitted to one side of the roller door opening and a reflective plate is mounted directly opposite on the other side of the opening. The sensor emits an infra-red beam to the reflective plate. In the event that this beam is blocked by a person or vehicle, the door will automatically stop and return to its open position.
- Radio Remote Control: Operated by remote control, radio operation systems provide convenience and simplicity to any installation.
Safety
- Touch Sensitive Bottom Bar: In the event that the bottom bar of the rolling door comes into contact with an obstruction before reaching the floor, the door will stop and return to its open position.
- Photocell: In the event that this beam is blocked by a person, vehicle or obstruction, the door will automatically stop and return to its open position to prevent a collision or injury.