When seconds count: SELVE freewheel makes NHK drives absolutely safe to operate in emergencies

Sometimes a seemingly simple approach turns out to be the pioneering and ultimate solution at the same time. SELVE’s  freewheel is seeing growing demand among professional customers – thanks to its sophisticated, reliable mechanics. When there is a fire and the power fails, every second counts. The innovative SELVE product completely rules out inadvertent cranking in the wrong direction with emergency-operation roller shutter drives. “In emergencies, when stress levels are high, there is no time to waste,” says Tino Braumann. “What is needed are products that are intuitive to use, provide absolute safety and quickly clear the way to the outside.” That is exactly what the compact, unobtrusive component ensures. It guarantees that the only cranking direction found is the correct one: upwards!

Cranking only in the upward direction

This is all the more important because the curtain inside the shutter box gives no visual feedback: “You cannot see which way you are cranking,” explains the SELVE Product Manager for drive technology. In an emergency, the wrong direction may not be noticed; in panic, cranking continues without the shutter opening. “The freewheel ensures no force is transmitted in the wrong direction and prevents the system from being damaged in the worst case,” says Braumann. The component is simply fitted between the crank rod and the universal joint and can be used for new and existing emergency hand-crank systems. “The effort is minimal: just remove the crank rod and install our ingenious solution in between,” the SELVE expert explains. Considering the product’s clear added value, the costs are comparatively low: for dealers they are in the single-digit euro range. With the mechanical freewheel first presented by SELVE at the last R+T, SELVE not only has a unique selling point on the market – the smart product idea also received the R+T Innovation Award (Silver). It was therefore obvious “to apply the benefits of the component, originally developed for textile solar shading and our escape-route drive SEZ-NHK, likewise to our roller shutter portfolio,” says Tino Braumann.

Perfect combination with SEE-NHK

As roller shutters become increasingly electrified, the need for special, life-saving drives for the second escape and rescue route is growing – in single-family houses and apartments as well as in offices, kindergartens or care homes. Among other solutions, SELVE offers the SEE-NHK for this purpose. In combination with the freewheel, it forms an optimal product pairing and helps prevent operating errors so that everything functions reliably in an emergency. “As a plug-and-play motor, the SEE-NHK unites all the well-designed features of the SEE – such as automatic end-limit setting and obstacle detection,” says the Product Manager. In everyday use the SEE-NHK can be operated conveniently via switch or timer; in case of a power failure, via crank with an especially fast 13:1 gear ratio. According to Tino Braumann, the SELVE drive is increasingly perceived by professionals as “the preferred candidate for emergency operation”. A special feature: if, in an emergency or even inadvertently, the shutter has been cranked up manually, the SEE-NHK automatically relearns its end limits.

Problem-solver for other manufacturers

Because the freewheel completely prevents cranking in the downward direction, it also becomes an important problem-solver for NHK drives from other manufacturers. “Most of them use a similar adaptor; their emergency hand crank is likewise connected to the system via a joint,” explains Braumann. The SELVE component therefore fits precisely in between and provides reliable operational safety in an emergency with little effort. Two versions (left and right) are always available. In addition to the previous freewheel – compatible with crank rods and universal joints from Geiger and Cherubini (round pin, 12 mm diameter) – SELVE now offers another variant. Responding to customer requests, the Lüdenscheid engineering team led by Jörg Tebbe developed a special solution for Geiger joints and crank rods with a flattened pin profile, 13 mm diameter.

Anyone wishing to see the convincing functionality of the freewheel for NHK drives can do so in SELVE’s explanatory video – available on YouTube and on the SELVE website. There you will also find various short clips on additional emergency-operation systems for the second escape and rescue route.

About Selve

SELVE is a global market leader in the field of roller shutter belt winders and a sought-after specialist for drives and controls in the areas of roller shutters and textile sun protection. Based in Lüdenscheid, Sauerland, SELVE represents a high level of expertise in the development and production of roller shutter components as well as innovative drives and controls for sun protection as a medium-sized family-owned company. Founded over 150 years ago in 1866 at its current location, SELVE remains under the ownership of the founding family to this day.