Marginal Column

Photo | Bosch Rexroth AG

An early TS 2 conveyor system

Non-stop motion

March 2011

 

The Dogumoba and the endless slot – conveyor systems in times of change.

 
 

Engineers at the Bosch corporation recognized a move toward industrial automation even in the early 1930s and knew how to make use of this insight. In the company’s own development, repair and maintenance shops the staff devised ways to move components resting on carriers or pallets. The real breakthrough in automated production was achieved with the first “Dogumoba” – the Doppelgurt-Montageband (or tandem-belt assembly line conveyor). It was unveiled in 1963 and is considered to be the grandfather of today’s pallet-based conveyor systems. It is manufactured entirely from steel and can stand up to severe use. Some of those early lines are still running. Further refinements in the concept resulted in workstations, processing stations and automated assembly centers being integrated as of 1970.

An infinite slot

What was then known as the “Bosch profile”, an extruded aluminum section, can be traced back to the “Dogumoba”. The need to affix sensors, switching elements and accessories along the conveyor required drilling many holes in the carrier track and frame, both made of steel. Changes – relocating sensors, for instance – were thus made difficult. An ingenious idea, the “infinite slot”, put an end to all that. This continuous groove makes it easier to attach additional elements along the conveyor path and they can be shifted without major effort. Standardized supports and crosspieces were the first components in the “construction set” containing the basic mechanical elements. That set formed the basis for the first modular conveyor system, the TS 2.

With the modular design, conveyor lines can be set up more quickly and configured to meet individual needs. They are considerably more compact, as well. Soon there were systems to handle differing weight classes: the TS 1 for lighter items of up to 3 kilograms; the TS 2plus, a true multi-talent, for workpieces weighing as much as 100 kilograms; and the TS 4plus for products as heavy as 250 kilograms. The “construction set” grew to match the tasks as systems were modified to suit changing manufacturing parameters. In the course of the 1980s the goals were “job enrichment” and “job enlargement”.

Workers’ activity ranges were expanded and the division of labor was made less severe, responding to society’s demand for “humanization of the working world”. This had effects on system layouts. Workstations not synchronized with the line were introduced and accumulator areas were integrated into the conveyor system.

A lean line

At the beginning of 1990s “lean production” was hip and “lean” processes were in demand. Complex, highly automated systems were slimmed down and replaced by easier-to-use units. Since then shorter conveyor belts with smaller drives have been added to the modular products portfolio. The conveyor systems must also keep pace with the short innovation cycles in the electronics industry. Here flexibility and reusability are in the limelight.

The developers embrace new ideas and employ modern materials to lower investment levels and operating costs. This has given rise to higher-efficiency drives and special slippromoting materials for the pallets. These reduce friction and, in turn, lower power needs. Today the TS 2pv conveyors move even delicate glass panels for solar systems safely from one workstation to the next. This industry is developing rapidly and will continue to find the required components in the in the Rexroth “construction set”.