Manufactured by Impéria, S.A., just to the south east of Liege in the town of Nessonvaux, the Imperia tool & cutter grinder was offered in two models, a top-of-the-range M6AR and the simplified, dry-grinding-only M6A. Besides having the ability to grind a wide variety of cutting tools, the M6AR could also - being fitted with a power-driven table - undertake surface, cylindrical and, with an optional kit, precision internal grinding.
Mounted on a stand fabricated from welded sheet plate, the cast-iron frame of the grinder was internally ribbed for extra rigidity and machined with two V-shaped ways for the table's traverse motion and a single V and a flat for its longitudinal.
Like all similar "universal" grinders, the table could be swivelled - in the case through 45° on each side of central and with a facility to both lock the middle position and also make fine adjustments to the angle set.
The whole carriage assembly could be moved in and out through 8 inches ( 200 mm) by a screw thread under the control of, at the front, a large diameter handwheel with its dial engraved in either hundredths of a millimetre (or thousands of an inch) and at the rear by a balanced handle with auxiliary graduations in five-hundredths of a millimetre (two-thousands of an inch). At extra cost, a reduction device for extra fine feeds could be supplied, this allowing graduations on the micrometer dials to show travel intervals as fine as 0.0025 mm (0.00025")
Longitudinal travel was 13.75 inches (350 mm) by hand or under power, in the former case by an enormously long lever, able to be mounted at either front or rear and used for rapid travel - and also by a handwheel for slow, fine control. With the table power-driven when surface or cylindrical grinding, automatic reversing stops - that acted upon a quick-action electrical switch - were provided.
Running in ball races, the hardened steel spindle carrying the grinding wheels was held in two housings forming a unit that could be removed and replaced should the belt have needed changing. This arrangement obviated the need to split the assembly and hence the need to reset all the various spindle bearing settings.
Mounted on a steel column, the wheelhead could be moved up and down though a range of 7 inches (180 mm) and swivelled to the left and right through 90° on each side of central. The column was protected by bellows against grit and dirt, guided by a long quill and maintained in position by a keyway. The column's vertical travel was controlled by a large handwheel on the front face of the machine working through a screw and helical gears. To secure the chosen setting, a long lever was fitted behind the wheel, its vertical position allowed the column to be free while the horizontal locked it. A micrometer dial of considerable size was fitted, engraved in hundredths of a millimetre or, optionally, thousands of an inch.
The workhead - the assembly carried on the table to hold a job - had a centre height of 5 inches (125 mm) and could be swivelled through 90° on each side of zero. Running in ball races, its spindle was in hardened steel and carried a nose formed with a No. 3 Morse taper - as well as a thread for the mounting of chucks and faceplates. The maximum distance between the wheelhead and tailstock was 20 inches (510 mm).
Power came from a 2800 r.p.m. main motor rated at 1.5 h.p., this being attached, together with a 4-speed belt-drive countershaft, to the bottom of the elevating column, the design ensuring that the spindle drive belt remained in perfect tension. The spindle speeds of 2900, 3900, 4900 and 5800 r.p.m. were changed by opening a door on the left-hand face of the stand, turning a handle to pivot the hinged motor so slackening the belt and allowing it to be moved from pulley to pulley.
Three other motors were fitted: the one used to elevate the wheelhead column being a 0.1 h.p unit running at 2800 r.p.m. unit and that on the workhead of identical specification, save for being a quickly-detachable type and driving through a 2-step V-belt drive. As, for some operations, the workhead motor was not needed, its removal in just a few seconds was essential and allowed changes of set-up with a minimum loss of production time. Coolant was pumped by yet another 0.1 h.p. motor also running at 2800 r.p.m. When the main motor was stopped, the other motors were also simultaneously isolated.
Lubrication of the machine was automatic, oil being in wells with sight-level glasses.
The Impéria has been found mounted on two different stands: an early type with a bulbous housing on the front face holding the electrical contactors and fuses and, on the left, an access door to the countershaft unit. What must have been a later version lost the electrical housing at the front and with the door to the countershaft moved to the right-hand face. As far as is known, the grinder itself remained unchanged.
The Impéria weighed approximately 1100 lbs, (500 kg), stood 53 inches high (1345 mm), had an overall length of 61 inches (1550 mm) and was 40.5 inches (1030 mm) front to back.
On the same site as the machine tool factory - sharing the same badge and almost certainly part of the same Company - was a car maker, Impéria Automobiles, a concern active in the industry from 1906 to 1948. The firm was one of only three in the world to have a test track on top of the factory building; 1 km long and built in 1928, parts of it survive and can be seen on Google maps. The other rooftop test tracks were on Fiat's Lingotto plant, opened in 1923, and Palacio Chrysler in Buenos Aires, opened in 1928.