email: tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sale & Wanted
Machine Tool Manuals   Catalogues   Belts   Books   Accessories

lathes.co.uk
"Amann" Lathes - France

Another lathe of French origin from a maker whose existence as an actual manufacturer was, for some time, in doubt. However, in January of 2019 a contributor to a French machine-tool discussion group recalled, when very much younger, meeting Mr. Amann when the latter was involved in the production of a small precision lathe, the 80 mm x 400 mm screwcutting "Petit Tour De Précision Type A8". The owner's company, Machines-Outils Amann S.ŕ r.l was located in Strasbourg with the factory's address given as Gare de Graffenstaden, a railway station to the south west of the city centre on the Rue de l'Industrie, from where the company still trades. The original offices were located at 16 Grande Rue de la Course - a location that still exists and with what appear to be all the original buildings.
Dating from the 1940s to early 1950s, the first Amann lathe shown below was of conventional design but, for its class, heavily-built. Backgeared and screwcutting, the lathes had a bed of deep section but - at an estimated 115 mm (4.5 inches) - a relatively low centre height, giving the machine something of a squat appearance. Flat-topped, the bed featured English-type narrow vertical ways guiding a carriage with long, plain, symmetrical wings and a centrally positioned cross slide. Both cross and top slide had feed screws fitted with small micrometer dials - that on the cross slide perhaps having the facility to be set using an external lever mounted concentrically with the feed screw.
Fitted with a large diameter leadscrew of rather fine pitch, screwcutting was by changewheels working through an ordinary tumble-reverse mechanism - the lathe also being fitted with a feed-shaft gearbox, the drive being taken by a gear from the leadscrew. While most other lathes with this simple system provided three speeds for each setting of the change wheels - the basic Harrison L5 being a typical example - the Amann appears, at a glance, to have had only one. However, the possibility exists that, out of sight on the left-hand face of the box, is a push-pull knob that did provide a change of ratio.
Of unusual appearance, the apron contained a train of reduction gears between the carriage handwheel and bed-mounted rack and a push-pull knob that selected the power sliding and surfacing feeds. It seems that the feeds would have been engaged and disengaged by a centrally-mounted, screw-in-and-out, knurled-edged dial. This method, if fitted, often results in a drive "winding up" during heavy cuts and, in consequence, very difficult to disengage.
The spindle, running in bronze bearings adjustable by front and back slotted rings was driven from a ball-race supported countershaft bolted to the back of the bed. Drive from motor to countershaft looks to have been by a single V-belt, but that to the headstock spindle by a wider-than-usual flat belt running over a 3-step cone pulley. Six speeds would have been available, these likely to have spanned something like 50 to 700 r.p.m. To slacken the final-drive belt in order to change speeds, an over-centre lever was provided, presumably fitted with some sort of adjustment to set the final tension.
Do you have an Amann lathe? If so, the writer would be interested to hear from you.
Continued below:


Backgeared and screwcutting, this Amann lathe had a bed of deep section but - at an estimated 115 mm (4.5 inches) - a relatively low centre height, giving the machine something of a squat appearance

Continued:
The other Amann lathe known about is the maker's original 80 mm x 400 mm "
Petit Tour De Précision Type A8". This, in its class, was a rather unusual concept being heavily built with an exceptionally wide, English-type flat-topped bed with narrow vertical guides for the saddle and a permanent gap in which material up to 260 mm in diameter could be turned. Bed and headstock were cast as one rigid part, the latter carrying a large diameter spindle, bored through 14 mm, running in bronze bearings lubricated through oil nipples and fitted with a 3-step, flat-belt-drive cone pulley. Drive came from a well-made countershaft mounted remotely behind the headstock, the maker's illustrations showing this being driven from a motor held beneath inside a braced sheet-metal stand. A number of surviving examples have been found on this stand, easily recognised by, on the left, a large door perforated with circular holes and, on the right, two full-depth drawers. It appears that at least two countershaft designs were made; one having a circular, trumpet-like base with no adjustment for belt tension, the other fitted with a swing-head. Unfortunately, slow-speed backgear was not fitted, nor does it appear possible that it could have been retrofitted, the result being that, while screwcutting was fitted, a beginner attempting it would have found the high spindle speeds difficult to cope with. Using a square-form thread, the leadscrew passed through a solid bronze nut bolted to the underside of the saddle; as the nut was not of the split type, disengagement of the carriage drive was arranged not by the usual simple lever-operated dog clutch - as used on virtually every other lathe with a full nut - but by the sliding the final drive gear in and out of engagement. 
With a 3 mm pitch, the leadscrew was fitted with a handle at the tailstock end and driven through changewheels that incorporated a tumble-reverse mechanism. A set of nine gears was provided - 20, 25, 30, 30, 40, 40, 50, 50 and 60 teeth - intended to generate just metric pitches.
With long wings set to its right-hand side, the saddle carried an ordinary compound slide rest, the cross slide being of the short type and the top slide able to be swivelled through 360. The top slide had an unusual feature: the area upon which the "clog-heel" toolpost rested was machined as a circle rather than a square, some the writer struggles to record seeing on any other lathe. Feed screws had ordinary, 60° angle metric threads rather than the preferred Acme and were fitted with tiny, non-adjustable micrometer collars. Unfortunately, both the cross-slide ways and feed screw were left completely exposed to the wearing effects of swarf and dirt.
Cosmetically, the finish appears to have been rather like that used on the German Hommel - known as "craquellee" - a mottling, paint-splattering effect also seen on some examples of the English Haighton Cadet
The little Amann would have been aimed at the same amateur market as the contemporary English EW - possibly the nearest lathe to it in terms of size and function, though of a very different design and construction. .


The owner of the Amann lathe has done a superb job of restoring it to full working order


Saddle, cross and top slide of the Amann Petit Tour De Précision Type A8

Underside of the top slide showing the ordinary metric-pitch feed screw

The feed screws, both ordinary, 60° angle metric threads rather than the preferred Acme, were fitted with tiny, non-adjustable micrometer collars. Unfortunately, the cross-feed screw was not covered and so left exposed at both front and rear to the wearing effects of swarf and dirt

The owner's company, Machines-Outils Amann S.a.r.l. was located in Strasbourg with the factory's address given as Gare de Graffenstaden, a railway station to the south west of the city. The works were on the Rue de l'Industrie, from where, as can be seen in this 2018 picture, the company still trades.

lathes.co.uk
"Amann" Lathes - France
email: tony@lathes.co.uk
Home   Machine Tool Archive   Machine-tools Sale & Wanted
Machine Tool Manuals   Catalogues   Belts   Books   Accessories