Landing door locks for safety-conscious Hewden

Without support, Hewden, the UK’s largest equipment rental provider, is leading the way in the development of health & safety features on its hoists. We’ve designed and manufactured a fully mechanical interlocking door lock system for Hewden’s goods hoists. This gives unsurpassed safety when the hoist is in motion or between landings.

These goods-only hoists are essential in the construction of high-rise buildings for the transportation of heavy materials to multiple landings. With the old mechanism, accidents could occur if the landing gates opened whilst the hoist was in motion, or had not reached the landing.

As there was no propriety lock available, Hewden approached Magnet Schultz Ltd to develop a new mechanism for its goods only hoists so a safety switch would establish whether the hoist had reached the landing before allowing the gate to be opened.

Before designing the new locking device Magnet Schultz set about fully understanding the function of the existing system and its shortcomings.

A Plug & Play mechanism

Magnet Schultz found the new lock could be manufactured as a ‘plug & play’ unit. This meant it would be quick and easy to install by non-specialist personnel.

As a result, Hewden would no longer have to employ and wait for a qualified electrician to install the mechanical locking device. Other factors that Magnet Schultz needed to take into consideration were:

• the lock needed to be weather proof
• a heavy-duty construction to cater for the harsh operating conditions
• incorporating a safety switch and fail-to-lock alert.

Magnet Schultz also had to determine the interfaces with other parts of the system, which involved:

• establishing both the switch and the push-button operations
• mimicking the proven heavy-duty locking beak into the new design
• incorporating industry-standard connectors for the daisy chaining of the landing locks.

With this essential work completed, the next task was to specify the performance requirements of the assembly including:

• function
• electrical power consumption
• mechanical protection
• operating life.

Key to this was the selection, adaptation and manufacture of a suitable shotbolt unit for the centre core of the assembly. As the world’s leading solenoid manufacturer, Magnet Schultz was in a unique position to develop the ultimate solenoid for the mechanism then design, prototype and build the assembly parts. This involved preparing detailed drawings, models, manufacturing and testing prototypes, followed by the final assembly.

“Magnet Schultz is an extremely professional company that put in time and effort to understand our requirements and was able to design a mechanism that fully achieved our goals. The company’s prototypes were thoroughly tested under extreme conditions and worked superbly. As the locks incorporate industry-standard connectors, they can be quickly fitted without us having to employ an electrician.”
Martin Brady, Service Manager. Hewden Hoists.

Such has been the success of the project, that Magnet Schultz Ltd was subsequently engaged by Hewden to develop a new shotbolt for another hoist gate system.