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Siome Covema Lathe (S.I.O.M.E.)
Multi-function Machine Tools

Built by the long-established Siome Covema (originally S.I.O.M.E.) Company in France during the 1960s and 1970s at the Zone Industrielle de Beauregard, 19 Brive (with technical and sales offices at 15 Rue de la Nouvelle France 93 Aubervilliers) the amazing Siome Covema Multi-function machine tools were built in a variety of types and stlesa. The model shown immediately below, the TA2, had the unusual ability to elevate its entire headstock under hydraulic control. This was a feature also found on some other S.I.O.M.E. lathes, with a much earlier example having the same facility built into what was otherwise a conventional backgeared and screwcutting lathe.
Built onto a massive cast-iron base, the TA2 was formed with a vertical slideway machined into the left-hand face of the bed that was used to carry a self-contained headstock sitting directly above a hydraulic accumulator and oil tank; in order to preserve the conventional aspects of the lathe a screwcutting leadscrew and power-feeds drive shaft were socketed into a gearbox (formed as part of the bed at its left-hand end) driven from the headstock by a universally-joined shaft; the same gearbox provided a vertical drive, though a sliding and keyed shaft, to an optional vertical head
Of a nominal 200 mm centre height (measured at the No. 4 Morse taper tailstock) and 1000 mm or 1600 mm between centres, for large diameter facing work the headstock could be elevated to 350 mm above the bed; to get the cutting tool at the right level a fixed-height raiser block was used under the top slide in conjunction with a packing piece beneath the standard-fit 4-way toolpost. Although the lathe was able to accommodate even larger jobs (with the centre height raised so that a disc some 840 mm in diameter could be swung over the bed) because the cross slide would have been drawn too far out for rigidity and safety the cutting tool could not reach the periphery of such a workpiece. In order to hold between-centres work above the normal level a special adjustable bracket was provided into which the tailstock barrel could be clamped.
The 38 mm-bore headstock spindle was driven through its speed range of 26.5 to 2000 rpm (or, optionally 33.5 to 2500 rpm or 21 to 1600 rpm) by a 2-speed 5/3.5 hp 3-phase motor. A cover on top of the headstock could be removed and, in its place, a three-way swivelling vertical milling head fitted; although this was a very useful accessory, with the operator able to set compound angles for machining in three planes, the lack of a quill feed would have restricted its ultimate versatility.
Entirely conventional, the carriage had a spindle start, stop and reverse control lever pivoted from the right-hand face of the apron and long, easily manipulated handles controlling the selection and engagement of the sliding and surfacing feeds. The 710 x 230 mm cross slide had three, long 12 mm traverse T-slots spaced 80 mm apart, a travel of 335 mm and was able to mount, in order to accommodate larger or more awkward jobs, a big 5 T-slot boring table formed with a circular clamping flange that enable it to be rotated to into the correct position.
The TA2 weighed 1800 kg as a short-bed machine and 2000 kg as a long bed..

Siome Covema TA2 Multi-function Machine Tool

The adaptor bracket bolted to the end of the bed was designed to carry the tailstock barrel

Although a very useful and well-built attachment the 3-way swivelling vertical milling head lacked a quill feed and needed a considerable effort to lift it into place.

Facing using the top-slide raiser block

Stub Milling

Horizontal Boring

S.I.O.M.E. TC-5 Lathe. In this illustration the connection between the headstock and bed-ends of the leadscrew has been broken by sliding back its dog-clutch sleeve.

S.I.O.M.E. TC-5 Lathe

Originally developed for use on board ship, this very unusual and interesting "elevating headstock" lathe was made in the town of Brive-la-Guillarde, France, by PMB (Précision Mécanique de Brives with premises at Rue de la Gare in the district of Malmort sur Corrèze (post code 19360 and phone: 05.55.92.20.49). Believed to have been designed by a Mr. Vives Antoine, around 4000 examples were produced with many sold to the French Navy and to locations where its versatility could be exploited or workshop space was limited. The lathe was also built in a version mounted on a stand that allowed it to be elevated through 90-degrees to act as a vertical miller. In this mode a generously-sized T-slotted table, mounted on an angle plate, was bolted to the cross slide and powered by an extension to the power cross feed drive. Although the original company was eventually to be declared bankrupt, the concept must have been successful for the examples shown below are clearly an early version of what was to be developed (perhaps by a company spun off from the original) into much more highly-developed models marketed as proper multi-function machine-tools.
Of approximately 5-inch centre height, and 20-inches between centres, the lathe had an English-style, flat-topped, right-angle edged bed of the cantilever type with its very deep central section bolted to a cast-iron "trumpet" stand. The headstock end of the machine was separate and, being connected to the bed by a vertical slideway, could be raised and lowered by a screwed rod with its control handle set just above the level of the headstock. The plain-bearing main spindle, fitted with a conventional backgear assembly, was driven by a pair of V-belts from a gearbox unit (bolted to the underside of the headstock), with a motor carried on an adjustable plate pivoting from its back face. A conventional a tumble-reverse mechanism and changewheels took the drive from headstock spindle to screwcutting gearbox - a unit fitted with a 4-position lever tumbler and a 3-position quadrant lever - an arrangement that gave 12 pitches for each setting of the gears. The leadscrew, used only for screwcutting, was fitted with a dog clutch in a sleeve that allowed it to be disengaged when the head was elevated. However, in order to provide power sliding and surfacing feeds (no matter what the position of the headstock), the power shaft was equipped with sliding splines and universal joints, rather in the manner of the drives fitted to many milling-machine tables: this mechanism, though not visible in the picture of the lathe, can be seen below in the illustration of a similar machine arranged as a vertical miller. 
Although the saddle was a decent length the fact that the bed ways could not be arranged to run past the headstock meant the cross slide had to be offset well to the left in order to let the tool reach right up to the spindle nose; this left two long right-hand saddle wings that the maker had equipped with longitudinal T-slots.
It is likely that the maker would have provided a range of raiser blocks to position under the top slide in order to allow turning in elevated-height mode, and it may be that even a version of the special tailstock-barrel clamp issued with later models might also have been available.
If you have a TC-5 lathe, or any sales literature or information associated with the makers, the writer would be interested to hear from you.

A mid-1960s version of the TC-5 lathe rigged as a vertical miller on a unique-to-the-model floor stand. This particularly fine example has had little use from new and is fitted with a T-slotted table powered by an extension to the lathe's power cross-feed drive.

View under the motor-mount assembly

Below - an older Siome Covema lathe