In 1923, two mechanic brothers, Felix and Louis Perrin, started a workshop at the "Corner of the Mill" in Moutier, Switzerland, naming their new enterprise after themselves and producing, first, cutting stamps for timepieces as well as being involved in the local watch-making industry by modifying and repairing watch-makers lathes and developing a rolling machine with pivoting clockwork gears. After some difficulties due to high unemployment in the area, they moved, in 1929, to Rue de la Gare in an old barn that was transformed into a mechanical workshop. Despite the harsh economic times some success was achieved with automatic coin sorters, a milking machine, a continuously-variable automobile transmission and the manufacture of jigs and spare parts for armaments - including templates and components for the Lebel rifles used by the French Army. In 1939, the company status changed from a limited partnership to a company: Perrin Frères SA. With the advent of WW2, the decision was taken to manufacture machine tools: first ordinary drill presses, some with compound tables (the model TX-25) then a universal milling machine, the PF1. However, it is reported that Deckel, in Munich, makers of the FP1, objected to the name and it was renamed the U1.
Built from the mid 1960s into the late 1970s, the Perrin AV-4 was manufactured by Perrin Brothers Ltd. in the little French-speaking town of Moutier, an important centre of Swiss watch, clock and high-precision industry. Also present in Moutier, besides many smaller specialist machine-tool companies, were the works of the famous A.Petermann, A.Bechler and Tornos, makers of Schweizer Landdrehautomat - Swiss Auto lathes used, typically, for the mass production of small parts.
The AV Series was amongst a range of co-ordinate drilling and light milling machines made by Perrin, some being intended just for drilling with a round column made from a steel bar and a V-belt driven head resembling that fitted to a variety of pre-WW2 drill presses. However, the AV models were quite different - and much more heavily built, the mill-drill-cum-jig-borer AV-1 and AV-2 optical jig borer being of identical dimensions and the jig-boring AV-3, AV-4, AV-4A and AV-4A versions rather more massive.
Constructed along established lines for this type of single-column machine*, the Perrin AV-4 had, unlike the removable types fitted to the AV-1, a compound table fixed permanently to the top face of the heavy base with all vertical settings by a head elevating on ways formed on the inside face of the box-section main column. While the AV-1 was advertised as a general-purpose machine, intended for accurate co-ordinate drilling but also capable of some jib-boring work, the AV-2, AV-3 and AV-4 versions were all built as an uncompromising jig borers and fitted with an optical positioning system on the table travels. Now obsolete, optical positioning systems were once in widespread use on high-precision machine tools, their quickness and ease of use - when compared to using dial indicators, slip gauges or length rods - being a great time saver. The optical projection scales read to 0.00005" and overall errors of positioning and repeatability did not exceeding 0.00015".
Specification details of the AV-4 are reproduced below.