Steute's Multiflex 4R pulley lets emergency pull-wire switches navigate conveyor bends, solving a longstanding design challenge for nonlinear material handling systems.
Emergency pull-wire switches have become established as "extended emergency-stop" buttons across industrial environments. They are especially common along conveyor belts. One pull on the wire, and the relevant part of the machine comes to a safe halt. It is a straightforward, proven safety mechanism that has saved countless limbs and lives over the years.
As long as the conveyor is running in a straight line, which is usually the case, the wire can easily be tensioned within the maximum approved deflection over distances of up to 2 x 100 metres. For this task, the accessories range from steute includes both closed and open eye bolts. The physics are simple and the installation is manageable for any competent engineering team.
But how can an emergency-stop function which complies with the standards and is easy to operate be realised along conveyors which go round bends, or in other extensive and non-linear hazardous areas? This is not a hypothetical question. Real-world material handling systems rarely follow perfectly straight lines. Airports, distribution centers, and mining operations all require conveyors that twist and turn to fit within the available space.
This question was brought to steute by a manufacturer of airport luggage conveyors. The challenge was genuine: how do you maintain reliable emergency-stop coverage when the conveyor path snakes through terminal buildings with multiple direction changes? The developers in the steute business division Controltec came up with an equally simple and effective solution which has now been added to the steute range of emergency pull-wire switches: the Multiflex 4R pulley.
The head of this pulley, guiding the wire, can be rotated to any position. This is the crucial design innovation. The Multiflex 4R thus provides a wire guide suited to conveyors which twist and turn in different directions. Rather than forcing engineers to break a continuous pull-wire run into separate straight segments, each requiring its own switch and tensioning, the pulley allows a single wire to follow the conveyor path around corners.
The important thing here is that even when the pulley is deflected multiple times, the friction is minimal, helped by the mobile rollers in the cavity of the pulley. Anyone who has tried to run a cable around a corner knows that friction builds quickly, and that resistance can make the difference between a functioning emergency stop and one that fails when someone pulls the wire. The system complies with a maximum deflection force of 200 N in conjunction with a maximum deflection of 400 mm, as required by EN 60947-5-5. Pulling the ripcord to actuate the emergency-stop function is comfortable, wear and tear is minimal, and even longer pull wires can be deflected multiple times without requiring a high actuation force.
Installation has clearly been considered as well. An M8 thread in the foot of the pulley facilitates simple and universal mounting of the Multiflex 4R. Alternatively, it can be fixed to conventional profile systems, for example conveyor systems for transporting packages and luggage, using a slot nut. This dual-mounting approach means it integrates into existing infrastructure without requiring custom brackets or fabricated parts.
Since its introduction, there has also been interest from many other areas of industry using conveyor technology. Tunnelling is a prime example. Here conveyor systems transport the stripped material out of the tunnel, often over considerable distances and around the natural curves of the excavation. An emergency-stop function is guaranteed by robust emergency-stop pull-wire switches. Sometimes the conveyors have to go round bends inside the tunnels, and then the Multiflex 4R is the perfect solution. It provides additional support for the extended emergency stop in combination with an emergency-stop pull-wire switch from the steute Extreme range.
What makes this development worth noting is the way it addresses a practical gap that many safety engineers will recognise. Standards for emergency pull-wire systems have long assumed linear installations. Real-world conditions rarely cooperate with that assumption. A solution that maintains compliance while accommodating the actual geometry of industrial environments is exactly the kind of incremental engineering progress that makes workplaces safer without adding complexity.
https://www.steute.com/
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Flexible pulley 1
Flexible pulley 2
steute USA, Inc.
901 Ethan Allen Highway
Suite 102
Ridgefield
CT 06877
USA
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steute Schaltgeräte GmbH & Co. KG
Brückenstr. 91
32584 Löhne
Deutschland
JOHNSON Isabel
Phone : +49 160 972 44 691
[email protected]