Geared for the future

In the first of a regular series Richard Collings looks behind the scenes of new equipmentdevelopment

JUST when it seems impossible to make a piece of kitchen equipment more robust, compact, reliable or easier to handle, customer demands can change manufacturers' minds.

Hobart Still has manufactured heavy-duty food mixers since the 1930s and the basic concept has hardly changed. However, over the past three years, the company's research has shown that some customers were using the equipment non-stop, which it was not really designed for. These customers demanded a longer life, more robust mixer which was better suited to constant use.

PROTOTYPE

The UK-led design team given the task of designing and producing a prototype for a new generation of mixer, dubbed the NCM, had four priorities in mind: making a product which was easy to manufacture, easy to assemble, easy to use and which complied with any forthcoming EC regulations. Senior project engineer Charles Kitchen began analysing the company's existing mixers.

"Large mixers the size we have been working on have been around for some time. They may have been revised, but the basic gearbox in them has been the same for about 50 years," he explains.

The design team rearranged the mechanics of the mixer to incorporate a steel-reinforced, polyurethane, positive-drive, flexible gear instead of the worm and worm wheel used previously. This meant torque was increased by 25%, making the machine more energy efficient.

Another change was an increase in machine capacity. Using the same bowl size and component parts, the NCM can mix 35lbs of pizza dough while its predecessors were capable of only 30lbs.

When dealing with the shape and size of the mixer, the design team set about changing the dimension of the present mixer format to enable it to fit snugly alongside a row of standard tables, without sticking out at the front.

The pedestal design was changed to make the mixer narrower front to back. It was made V-shaped with the bowl sinking into it, rather than protruding on top.

Kitchen used computer-aided design equipment to work on all the new features of the New Concept Mixer. This supersedes the more traditional design approach using wooden mock-ups.

Computer software also enabled the team to eliminate many structural problems and weak spots highlighted by a structural engineer at an early stage, which would otherwise have needed reinforcing.

Safety was high on the list of priorities when designing the mixer, to keep it in line with EC regulations. The guard was designed to slope outwards slightly, fitting around the bowl.

Throughout field trials, changes were made to the original design and the NCM was finally launched in the UK at World of Hospitality earlier this year. o