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 late 1950s into the late 1970s, the Perrin AV-1 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 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.
Intended as a machine capable of performing co-ordinate drilling, vertical milling and jig boring, the AV-1 was the joint smallest of a range consisting of the AV-2 (a machine of identical size to the AV-1 but constructed as a dedicated optical jig borer) and the much more heavily built AV-3, AV-4, AV-4A and AV-4A. Perrin also made a number of lighter co-ordinate drilling and light milling machines, 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 massive.
Constructed along established lines for this type of single-column machine*, the Perrin had its compound table bolted to the top face of the heavy base with head elevating on ways formed on the inside face of the box-section main column. Although not capable of performing as a jig borer to the standards set by, for example, the dedicated SIP and Hauser types, it cost considerably less and was still able to work within limits stated by the maker to be 0.0004" on hole spacing: we have endeavoured, based on our long experience in this field, to produce a machine to fill the gap existing between drilling and/or vertical milling machines and the high precision jig borer."
Of substantial proportions, the base of the AV-1 was cast as one piece and held the motor, its control gear and thermal overload switches. Drive from the 2 h.p. 3-phase, 420- volt, 1500 r.p.m. motor passed to a V-belt driven, mechanical expanding and contracting variable-speed drive and a 2-speed gearbox fitted with hardened and ground gear teeth with lubrication by splash. At extra cost a coolant tank and electric pump could be built into the base.
The main column was bolted to the base and machined with prismatic guides upon which ran a head, with a travel of 18.5" by a handwheel on the column's left-hand face. Sliding in a honed bore, the quill held a hardened and ground spindle running in high-precision taper-roller bearings and formed with an external "non-stick" 8?32' taper and an internal No.2 Morse. Drive from the gearbox passed to the spindle by three V-belts, these sliding up and down a rotating shaft within the main column in sympathy with the head's vertical movement. The standard speed range, as supplied for the UK market, was in 2-steps that spanned an infinitely variable (and very useful) range from 50 to 3200 r.p.m. Unfortunately speed changes had to be made by a handwheel fitted inconveniently towards the back of the right-hand face of the base, a tachometer on the right-hand face of the column indicating the revolutions in use.
Quill travel - a maximum of 4.725" was available - was under the control of a 3-spoke capstan wheel for coarse settings, a micrometer-dial-equipped handwheel on the head's front face for fine settings and three rates of power up and down feed, these being set at 0.002, 0.004 and 0.008" per revolution.
Formed with T-slots, the top of the base was intended to accommodated a variety of bolt-on tables including, in later years on the larger models both power-driven and CNC-controlled types. However, when launched, a choice of just two was offered for the AV-1: the TX-25 and TX-40. The former had a clamping area of 10.235" x 11.810", a longitudinal travel of 9.843" and in traverse of 7.087". Three -slots with a width of 0.394" on a spacing of 4.1342 were provided and the maximum distance been the spindle nose and the table top 19.685". The TX-40 was considerably larger at 11" x 19.685" with a longitudinal travel of 16.140", in traverse of 11" and with three 0.472" wide T-slots on a spacing of 4.134". The maximum distance between the spindle nose and table top was 18.5". Feed screws were made from a high-grade. chromium-nickel steel with table positioning monitored by engraved rulers and huge micrometer dials engraved at intervals of 0.001" (one revolution giving a very slow-rate travel of 0.2"). For greater accuracy in positioning when jig boring or other critical work, the makers offered the usual dial indicators and provision to fit length rods and slip gauges. Interestingly, not only were the millers given the expected serial number, but the tables were too, in their own dedicated series.
Fitted with the smaller table the AV-1 weighed approximately 1500 lbs and with the larger 2000 lbs. Space necessary for the TX-25-equipped model was around 44.25" front to back, 41.75 wide and 71.5" high. Rquavalent figures for the TX-40 equipped machine ran to around 51" x 56.252 x 71.5".
Supplied with each new AV-1 was a complete electrical installation including low-voltage lighting; a superb Albrechts 3/4" capacity chuck on a No. 2 Morse arbor; a set of spanners; a grease gun, instruction manual and accuracy test report.
* examples of single-column jig borers include: Hauser, Linley, Downham, Vernon, SIP 1H, SIP 2P, S.A.D.A.M.E.L and the larger of the two BCA models.