The mass production follows the same general evolution: reduction of the batches, increase of the changes, total quality, reactivity and competitiveness. Turning follows this as well. It must adapt its means to new models of production organisation. Visit to Société Industrielle de Boulay.

Located in two production places, at Boulay in Lorraine and at Laboissière in Thelle, SIB-ADR produces and deals metal items and plastic parts. A wide manufacturing program is addressed to electrical industries with standard and special products.
The metal products are manufactured in the Boulay workshop. They mainly consist in stuffing nuts, lock nuts, fittings and sheaths, terminals and all related accessories. The company produces 80% of the product dealt. With a turn over of about 90 MF, a personnel of 135 persons, the company exports about 30% of its production, in particular to Germany.

INCREASING THE PRODUCTIVITY THROUGH THE INVESTMENT
Like all production units of this type, producing about 5 million of parts per month, the productivity increase is a continuous fight. Moreover, it is necessary to invest with judgement, that is not always easy in a field in which the competition is extreme, as well as the quarrels of the money specialists towards the production concepts.
Here, like elsewhere, the traditional production means have always been the single-spindle lathes. The problem was, of course, their adaptability to the new necessities. Mr. Eichisky, president and general director of SIB, says: "Considering the batches sizes, the product life, the working conditions, we have chosen, with success, the solution of the single or double bar transfer machine".
Actually, the rationalisation made divides the production unit into CNC lathes, mechanical multi-spindle lathes, transfer machines. This sharing has the advantage to increase the utilisation of the machines and to decrease the stocks, notwithstanding an incompressible threshold of 20%, due to the nature of the products manufactured. This logic can be better explained considering that the raw material (brass) often represents 50%-70% of the final cost price of the component produced.

THE TRANSFER MACHINE: A PERFORMING SOLUTION
SIB-ADR has acquired 5 transfer machines, 4 of which manufactured by the Italian constructor BUFFOLI, represented in France by the company EVAMO. Two types of machine produce batches from 10,000 to 200,000 parts (editor's note: today the customer uses the single bar transfer machines also for batches of 500-5,000 parts). Three machines fed by double bar and one machine fed by single bar (editor's note: in the meantime the customer has purchased a further single bar machine). The principle of the double bar machine allows a significant save in terms of area occupied and optimises the investment of 3,2 million of French francs.
These transfer machines, which are real working centers designed for turning, are fed by hexagonal bars (but it is also possible the feeding by round or profiled bars). The part working process is completely automatic, until the ejection of the finished part. The four machines are controlled by two operators and can work autonomously. The autonomy depends mainly on the bundle bar feeding.
"Comparatively, a transfer machine, in average, is equivalent to about four mechanical multi-spindle lathes. This is extremely important, if one thinks that the financial investment is practically the same as the investment of a modern multi-spindle lathe", M. Eichisky, who has carefully evaluated the choice, says.
The chosen solution enforces drastically the company competitiveness, taking in consideration the small margins, but also the investment capacity and mainly the area aspect that, like for many companies, is an unproductive factor and an additional cost to be added to the sale price. But it is not all; the dead times, like the ones for the part change, have been practically reduced by one third in comparison with the existing machines. The return of the invested capital is then considerably faster, taking in consideration all these productivity factors.
"On the other hand, M. Kieffer, the responsible of the times and methods department, says, it is not to be neglected the rotating tool factor, allowing a better adaptability to the cutting conditions, without forgetting the operator utilisation comfort, especially as far as the noise factor is concerned". The quality of the machining is optimal due to the independence of the working stations, to the perfect coaxial clamping of the parts and to the possibility of working 4 or more faces of the part. Similarly the transfer machines can work producing 1, 2 or 4 parts per cycle.

A RANGE ADAPTED TO THE PRESENT PRODUCTION
Buffoli manufactures bar transfer machines with a basic range including three models: TRB45, TRDB45 and TRB75 (editor's note: more recently the models TRB25 and TRDB25 have been introduced). The TRB45, single bar transfer machine, and the TRDB45, double bar transfer machine, allow the turning of bars with diameters from 15 to 45 mm. The TRB75, single bar transfer machine, allows the turning of bars with diameters from 30 to 75 mm. Of course, according to the cases examined, the machine can be adapted very easily to the necessities.
The integrated bar loaders allow to work in completely automatic mode, loading bar bundles up to 3 tons, with length up to 6 meters. The bar rejected parts are much less (about 5 times), allowing material saving. They are evacuated automatically into a box separated from the box of the finished parts. Through a simple and effective surveillance device, the operator is able to assure a total quality. This device allows a surveillance of the critical dimensions and of the drift due to the tool wearing.
Through a CNC optimised for the turning operations, the instruction and the machine use are learnt quickly by the operators. "We have been operative quickly, thanks to a training so quick as effective that has no equals in the traditional training", M. Eichisky confirms.
The operator has access to a conversational CNC. The programs can be introduced either on the machine or in office. Through a control PC, all the working parameters can be saved. DNC connection, modem for the tele-assistance, systems for the protection of the production data and statistics of the machine stops are, among others, some of the possibilities of this multi-processor CNC.

A FUTURE ENTERED IN THE ECONOMY
"The transfer machine principle applied to the turning allows a significant evolution thanks to all economical advantages for the turning companies." M. Jullière, owner of EVAMO, dealer of these transfer machines, says.

Through a serious analysis, based on the market reality, the transfer machines for turning enter their future in the economical evolution, like the numerical control machines in the past.