"EPVJ" is believed to stand for Ecole Professionnelle de la Vallée de Joux, a Swiss technical training institution that had, over time, a number of different names including,
until 1935: Ecole d'horlogerie; from 1935 to 1966 it was known as the Ecole Professionnelle de la Vallée de Joux; from 1966 to 1972 the Ecole Professionnelle Technique de la Vallée de Joux and from 1972 to date the Ecole Technique de la Vallée de Joux (ETVJ).
Probably manufactured in small batches during the period 1935 to 1966 it reflected a Swiss practice of technical colleges actually making complete machines, another example believed to have been the EML Ecole des Métiers Lausanne.
Bearing a passing resemblance to both the Swiss-made Schaublin 102 and Haibegger TDLE "Neotor", the EPVJ was also of very high quality and around the same capacity - the centre height being 102 mm (4 inches) and the capacity between centres approximately 500 mm (20 inches). The bed was built with unusually large, integral feet at each end and its central ways formed in the same style as found on many other traditional precision bench lathes - a flat top, bevelled edges and a central T-slot used to locate headstock and tailstock. The carriage (moved by a very large handwheel that could be disengaged while screwcutting) ran on ways, like those of the Schaublin 102, formed as extensions to the bed's front and back walls with the front V-shaped and the back rectangular.
As was usual on this class of the lathe, the headstock spindle carried its pulley with the smallest diameter to the right, so allowing the all-important front bearing to be surrounded by as great as mass of metal as possible. The pulley cone had four rather than the more usual three steps, the smallest being made only a little larger than the diameter of the spindle to allow a high top speed to be provided. Although not confirmed, it is likely that the spindle ran in a precision ball race at the front and some form of combined axial and thrust race at the rear. However, if the bearings were of the plain type, the spindle would have been hardened and ground and carried in adjustable bronze bearings - that at the front formed with a long, shallow possibly 3-degree taper and short 45-degree taper (in the manner first adopted in 1865 by Stark in the USA) with a plain parallel bearing at the other end.
Very Schaublin-like, the compound slide rest used the same design of good-sized, bevelled-edge zeroing micrometer dials with balanced handles and the top slide carrying two parallel T-slots machined so that the bolts could be withdrawn either to the front or rear.
Screwcutting was by fine-pitch changewheels with, rather ingeniously, a rod below the leadscrew, operated by a handle pivoting from the apron's right-hand face, causing some form of dog clutch to engage and disengage the drive to the changewheels, the mechanism being buried inside the end section of the headstock. Tumble reverse was fitted, the operating lever with its spring-plunger being positioned vertically to the rear of the headstock's end cover.
Like that fitted to most precision lathes from the 1860s onwards, the tailstock carried a barrel (spindle) that passed right through the casting and was thus fully supported by the surrounding casting, even when fully extended. A proper compression clamp lock was fitted and, to the front of the machined surface in front of the lock, a reservoir and dipper rod to apply the (now banned) white lead with which to lubricate the centre.
If you have a EPVJ lathe, or knowledge of its origins, the writer would be very interested to hear from you.