ITALY 07The Lineage of Italian Gear Machines

Imported gear cutters and Torino's car factories (1877–1930s)

The first record of Italy and gear machines is in the company history of the American firm Gleason. Gleason's bevel gear cutting machines from Rochester were first sold abroad in 1877, to Italy^[1]. The bevel gear cutters of this period used a template that traced the tooth shape, guiding the cutter along it to cut the tooth flanks (for Gleason's development, see the chapter on American gear machines).

1908: the “template-free” gear cutter drawn by a Milano technical journal

Once cars took to the road, bevel gears for gearboxes and rear axles were needed in large numbers. In 1907–08 the Milano technical journal Il Politecnico ran a long series by Alfredo Galassini, “Dentatrici coniche senza sagoma” (bevel gear cutters without templates). The 1908 volume dealt with the new template-free machine that Gleason built after perfecting a machine that used three templates. The drawings were made from a machine actually running in one of Torino's major car factories^[2].

This machine imagines a flat imaginary crown gear as the gear that the bevel gear meshes with. Two cutters act as the two flanks of one tooth of that crown gear; when the gear blank and the cutter carriage are turned together at the same ratio as the crown gear and the gear would mesh, the reciprocating cutters gradually cut the tooth flank as an “envelope.” When both sides of a tooth are done, the cutters withdraw and the indexing mechanism turns the gear to the next tooth. The advantage was that correct tooth profiles could be produced for any number and size of teeth without making new templates^[2]. This idea of “rolling with an imaginary crown gear” lives on in today's bevel gear generators.

The 1909 inspection report: Itala and the works in Rome

In May 1909 Godfrey Carden of the US Department of Commerce and Labor visited the Torino car company Itala (about 800 workers). The works had the Fellows gear shaper from Springfield in the US, three 26-inch Brown & Sharpe gear cutters, and German Reinecker gear cutters and a Biernatzki hobbing machine. Among Italian-made machines there was a gear cutter by Torino's Dubosc (spelled “Dubose” in the report)^[3]. The Fellows gear shaper generates teeth by moving a gear-shaped cutter (pinion cutter) up and down while turning it together with the blank, and can cut the stepped gears of gearboxes and internal gears. The Brown & Sharpe gear cutter was an automatic machine for form cutting, one tooth space at a time with a cutter shaped like the space. Generating and forming, American and German machines side by side in one factory: that was Italy in this period.

The army's precision works in Rome, the Laboratorio di Precisione (about 150 workers, making rangefinders and gun sights), had a bevel gear planer by the American firm Bilgram. The Bilgram machine generates bevel gears with a single reciprocating cutter. Carden wrote that although he had been told it was bought directly from the US, its nameplate bore the name of an Italian company. The same works also had an old universal spiral gear cutter by Greenwood & Batley of Britain^[3].

Lancia's gear-cutting department (1911)

In 1911 Lancia of Torino set up a gear-cutting department in its new works at Borgo San Paolo. It brought together two Bilgram, one Fellows, two Brown & Sharpe and one Savant machine from the old works, and Gleason, Brown & Sharpe and Reinecker machines from Fides, with which it had merged; before the war it added Brown & Sharpe machines and those of Sunderland of Britain, and then Gleason and Fellows. Its gear cutting machines grew from 2 in 1907 to 17 at the end of 1914^[4]. Bigazzi and Subbrero, who studied the plant registers, see this line-up, with almost every type of maker and model, as a sign of a factory keen to try new machines. The British Sunderland is a planing-type gear cutter that generates teeth with a rack-shaped cutter. An article in the American trade journal American Machinist in June 1924 put Lancia at the head of Europe in its use of American gear cutting machines^[4].

What changed in this era. Car gears had to run quietly and be made in large numbers. With the move from machines that traced templates to generating machines that form the tooth profile by “rolling” it with a mating gear (Bilgram, Gleason, Fellows, Sunderland and hobbing machines), the accuracy of the profile came to be set by the machine and the cutter, and the same gear could be made without highly skilled craftsmen. Italian factories were quick to buy machines that had only just come onto the market in the US.

Postwar recovery: Samputensili and Sicmat (1948–1974)

Gear cutters carried off

At the end of the Second World War, machines in the factories of northern Italy were carried off by the German army. After the war the official gazette repeatedly printed lists of machines recovered from Germany and Austria, asking their owners to claim them. The 11th list, of July 1949, includes two radial drilling machines of Torino's Sicmat, and the 12th, of October, includes eight small gear cutters for worms and gears, the Italmikron D-55 (maximum module 3, with change gear boxes)^[8][9]. Lists of compensation for property that could not be recovered went on until 1968, and among them are two gear cutters by Minganti of Bologna^[17]. All of this is evidence that gear cutters and machine tools were being made in Italy before the war.

Marshall Plan gear cutters

Large car makers bought new machines with American loans. In 1948–50 Lancia received American loans (IMI-Eximbank and ERP, the Marshall Plan), and its orders to the US included six gear cutting machines, among them a new Gleason. A further application of January 1951 (not realized, as the aid did not continue) included six automatic hobbing machines from Barber-Colman of the US, with the reason given that “one man can tend 3–4 machines, so gears can be mass-produced cheaply.” A Gleason lapping machine for finishing bevel gear sets was also in the plan^[4]. In 1959–63 Lancia's gear cutting machines increased from 52 to 97, and loading devices that changed workpieces automatically went as far as having one person tend a group of nine machines^[4]. The aim of automatic hobbing machines was less to make each machine faster than to increase the number of machines one person could tend.

In the Cold War, gear cutters were also strategic goods. In September 1950 the American magazine U.S. News & World Report listed “Italian gear-cutting machinery” among goods believed to be flowing to the Communist bloc^[10].

The birth of Samputensili (1949)

In 1949 an independent division making gear cutting tools was born out of Bologna's precision engineering company SAMP (Società per Azioni Meccanica di Precisione): Samputensili (meaning “SAMP tools”). SAMP had been started in 1936 by Gaetano Maccaferri as a small factory making wire machinery; unable to obtain good gears, it made its own, and during the war it supplied precision gears to the air force^[5]. Its first customer was the Italian Air Force, and it had 20 employees. Because the machines on the market could not give the quality it needed in its tools, it built the machines for making the tools itself^[6][7]. Gears for aircraft engines and transmissions have to be light, strong and highly accurate, and the tools that cut them need especially tight accuracy. In 1952 it opened a sales office in Germany^[6].

In September of the same year, 1952, the weekly bulletin of the US Department of Commerce carried an inquiry from Samputensili of Bologna. It wanted to build gear cutters, gear shapers, hobbing machines and rotary shaving cutters under American license, to export those tools, and to buy tool steel^[11]. It shows that the tool company already had its eye on the machines that use the tools.

Import liberalization, and large gear machines that still had to be imported

In June 1957 the Italian government added to its list of items made easier to import from the dollar area (the US and others): gear shapers of 800 mm diameter and module 8 or above, single-spindle hobbing machines over 40 t, herringbone (double-helical) gear cutters, gear rolling machines and gear grinding machines^[13]. Machines for large gears and for finishing hardened gears still could not be made in Italy and had to be bought from the US. A British trade journal also wrote in 1960 that the Italian machine tool industry had grown fast after the war, but relied on imports for types of machine whose home market was small^[14].

Sicmat's shaving machines (1961)

Meanwhile, Torino's Sicmat (Stabilimento Industriale Costruzione Macchinario Attrezzature Torino) built the gear shaving machine, used to finish car gears. The SSU 310 universal shaving machine, presented by a British trade journal in 1961, handled gears of 1–12 inches (about 25–305 mm) in diameter, and its cutter head could swivel up to 25° to either side. Load the work and press a button, and air pressure clamped the headstock and tailstock, the guard closed, the table rose to mesh with the cutter, and the machine ran a set number of strokes to complete one cycle^[15].

Shaving is a finishing process in which a gear-shaped cutter with finely serrated teeth is run in mesh with the gear with their axes slightly crossed, paring a thin layer (around 0.1 mm) from the flanks. Because the axes cross, the flanks slide sideways against each other, and this sliding lets the serrations cut the flank. The SSU 310 had three feed methods: conventional (axial) feed, which moves the table back and forth along the gear axis; diagonal, which feeds at an angle to use the whole width of the cutter; and underpass, which feeds at right angles to the gear axis with a cutter wider than the face width. In general, the more angled or perpendicular the feed, the shorter the time per gear and the more even the cutter wear. “Hobbing → shaving → hardening” became the standard process for postwar car transmission gears (that Germany's Hurth built a helical gear shaving machine in 1946 is covered in the chapter on German gear machines)^[1].

A gear inspection machine that measures electronically (1967)

Samputensili also built measuring machines to check the accuracy of its tools. In March 1967 its Carlo Occhialini and Claudio Tattini filed an Italian application for a machine to inspect helicoids (the helices of hobs and worms) and involute profiles; it also became US Patent 3,534,481 in 1970^[16]. The machine picks up frequencies recorded on two rotating drums with heads that read them as they turn, and measures the error in transmitted rotation (transmission error) as the phase difference between the two frequencies. It compares a turning gear's “running ahead” and “lagging behind” as electrical signals, an early example of the move from mechanical measurement, which traces the profile with gears and a stylus, to electronic measurement. The 1969 index of a British trade journal also lists Samputensili's type SU 130 hob and worm tester^[18].

In 1971 Samputensili opened a new plant at Ortona (province of Chieti) in the south, and in 1974 it set up subsidiaries in France and Brazil. The Brazilian plant later became one of the group's main tool plants^[6].

Finishing machines: chamfering, cutter grinding, gear grinding (1975–1997)

Chamfering and deburring: dressing the tooth ends

When teeth are cut with a hob, the tooth ends are left with burrs (turned-up metal) and sharp corners. If the gear goes on to shaving or hardening like that, the corners chip, or harden too deeply and crack, or chips break off after assembly and travel around inside the transmission. In 1975 Samputensili's answer, its first chamfering machine, came onto the market^[6]. In May 1977 Occhialini filed an Italian application for a tool that mounts a cutter for chamfering the gear ends and a disc for removing burrs on two parallel shafts, processing both at once from the same dimensional reference (US Patent 4,290,718, granted 1981)^[19], and in January 1980 he filed for a device that makes it easier to mesh the chamfering/deburring tool with the gear (US Patent 4,412,765, granted 1983)^[20]. Because chamfering tools also mesh and turn like gears, matching up the teeth during setup was a problem.

A machine for resharpening shaving cutters

Shaving cutters are expensive tools; when worn, their flanks are reground and they are used again and again. If regrinding shifts the profile, the profile of the gears finished with the cutter shifts too. In 1977 Samputensili brought out its first shaving cutter grinding machine, and began selling the machine it used to grind its own tools to the customers who used those tools^[6]. In 1982 it brought in-house the equipment for PVD coating (depositing hard films such as titanium nitride on tools in a vacuum)^[6]. The tool company now did everything itself: making, regrinding, coating and measuring its tools.

Gear grinding machines (1988)

In 1988 Samputensili brought out its first gear grinding machine and set up Samputensili America in the US^[6]. Gear grinding is a finishing process that grinds flanks distorted by hardening back to the correct shape with a grinding wheel. Shaving is done before hardening, so hardening distortion remains. For car gears that must be quiet, and aircraft and helicopter gears that must be strong, grinding after hardening became more and more common. Gear grinding machines include profile grinding, which grinds one tooth space at a time with a wheel shaped like the space, and generating grinding, which grinds continuously with a threaded wheel; Samputensili later built both kinds^[6].

In the same year, 1988, Bossi and Miletto, engineers at Sicmat in Torino, reported in a paper on a shaving center to be built into an FMS (flexible manufacturing system)^[22]. The direction was to automate loading and unloading and cutter changes, so that many kinds of gears could flow through without human hands. A March 1980 Italian newspaper carried an advertisement for East German machine tools listing cylindrical gear grinders and hobbing machines and straight and spiral bevel gear cutters^[21] (for East Germany's Modul and Niles, see the chapter on German gear machines).

Samputensili set up subsidiaries in Japan in 1991 and Korea in 1995, and opened a sales office in Beijing in 1996^[6][23].

What it means on the shop floor. Of today's gear process, “hobbing → chamfering and deburring → shaving → hardening → gear grinding (or honing),” Samputensili was the company that supplied the machines and tools for the middle and later stages under one roof. Shop-floor problems, such as gears left unchamfered chipping the edges of shaving cutters and reground cutters with shifted profiles, can be said to have pushed a tool company into making machines. For how each tool is used, see the shaving cutter page.

Chemnitz, Star SU and going international (1998–2014)

Buying a long-established hobbing machine maker (2000)

From 1998 Samputensili began selling jointly in its main markets with the Chemnitz hobbing machine maker Hurth Modul of Germany, and in 2000 it bought the company. Spur and bevel gear hobbing machines joined its range, and the Chemnitz plant became part of one network with the plants in Brazil, the US, France, Japan and Korea^[24][6]. The Chemnitz plant, started by Hermann Pfauter in 1900, was the original home of the hobbing machine, and in East German times it was VEB Modul. Its history is in the chapter on German gear machines. A hobbing machine turns a screw-shaped cutter (the hob) together with the gear blank and feeds the hob across the face width to cut the teeth continuously. The tool company had acquired the machine that uses its tools the most.

Star SU (2002) and Fellows cutters

In 2002 Samputensili's American subsidiary SU America and Star Cutter of Michigan, USA (a tool maker founded in 1927)^[40] combined their sales of gear cutting tools and formed Star SU as a 50/50 joint venture^[25][6][7]. In the same year Samputensili bought the Fellows pinion cutter division in the US^[6]. Fellows had made gear shapers and gear-shaped cutters since 1896, and had stopped operating in February 2002 because of its parent company's bankruptcy^[25] (the chapter on American gear machines). The cutters of the Fellows gear shaper, a machine already at Itala in Torino in 1909, passed to an Italian company some 90 years later.

Also in 2002 Samputensili launched the CDM series, which hobs and chamfers/deburrs on a single machine; in 2003 its threaded-wheel generating gear grinder, the S 250 G, came onto the market^[6]. Generating grinding turns a threaded wheel like a hob, synchronized with the gear, and grinds all the teeth continuously; it is faster than profile grinding one space at a time and suits mass-produced car gears. Keeping the wheel and gear rotation precisely in step is the job not of a mechanical gear train but of electronic synchronization by the CNC (an electronic gearbox). In 2005 the company began using the wear-resistant coating Alcrona on its tools and set up a joint-venture tool plant in Shanghai. Its workforce worldwide reached 560^[6].

SAMP's three divisions, and letting go of Chemnitz (2010)

In 2006 Samputensili, Sampingranaggi (a plant making spur and bevel gears) and Sampsistemi (wire and cable machinery) were combined as the three divisions of a new SAMP S.p.A. SAMP is one of the companies of the Maccaferri family's industrial group in Bologna^[6][26]. In 2007 Star SU took over North American sales of Torino's Sicmat shaving machines. Sicmat's customers included Fiat, Piaggio, Renault, GM, John Deere and Caterpillar^[27].

2010 was a turning point. In February the Maccaferri group announced plans to close the Ortona plant, and workers opposing the 139 layoffs protested on the factory roof^[28]. In October Samputensili sold its Chemnitz hobbing machine and chamfering/deburring business to the US machine tool group MAG (becoming MAG Modul Verzahntechnik), and narrowed its focus to tools, gear grinding machines and multifunction gear machines. In North America, Star SU continued to sell and service both companies' machines^[29]. Its European plants were consolidated at the Technology Centre in Bentivoglio near Bologna^[23]. The Star SU partnership spread to South America (Star SU do Brasil) in 2014 and to China (Star SU China) in 2015^[30].

★Restructuring: EMAG SU and Star SU Europe (2015–)

In 2015 Samputensili bought Sicmat of Torino and moved shaving machine production to Bentivoglio. In October it showed the RASO 200 shaving machine at EMO Milano^[31]. A Torino company that had built machine tools before the war and specialized in shaving machines after it had passed to a tool company of Bologna.

In January 2016 the Samputensili division of SAMP split into two companies, Samputensili Machine Tools (machines) and Samputensili Cutting Tools (tools). The company described itself as having built machine tools for about 50 years, ever since it began doing so for the sake of tool quality; its strengths were hard finishing (finishing after hardening) and chamfering/deburring, and many of its machines came standard with direct drives, linear motors, energy-saving design, processes that run setup and machining in parallel, and on-machine measuring and dressing devices^[30].

In February 2021 the German lathe maker EMAG bought Samputensili Machine Tools and Samputensili CLC and made them EMAG SU. Shaving, shaping, gear grinding and profile grinding machines joined EMAG's range, and in June 2022 a new plant opened at Anzola dell'Emilia in the province of Bologna^[32][33] (EMAG's hobbing machine maker Koepfer is covered in the chapter on German gear machines). On the tool side, the partnership with Star Cutter spread to Europe in 2022, and under the name Star SU Europe the company makes hobs, skiving cutters, master gears, chamfering tools, pinion cutters and shaving cutters at Bentivoglio^[7]. The Bologna tool company that began with 20 people in 1949 lives on today split in two: the machines in a German group, and the tools in a company allied with an American group.

Industries that use gears: cars, motorcycles, helicopters

Italian gear machines were nurtured first of all by Torino's car industry. The template-free Gleason bevel gear cutter of 1908 was running in a major Torino car factory^[2], and Itala in 1909 and Lancia's gear-cutting department from 1911 gathered the latest American and German gear cutters^[3][4]. After the war Sicmat's shaving machines went into car factories in Europe and America, starting with Fiat, and its customer list also includes Piaggio, the scooter and motorcycle maker of Pontedera^[27]. Just as Samputensili's first customer was the Italian Air Force^[6], aircraft gears helped push up the accuracy of tools.

One place where gear technology is concentrated in Italy today is helicopters. Leonardo's helicopter division, descended from the former Agusta, has its transmission development and production center at Cascina Costa in the province of Varese. In a plant of about 21,000 m², it does everything in-house from raw material through turning, gear cutting, dimensional inspection, welding, heat treatment, grinding, finishing and lapping, and the company says the AW139 was the first helicopter with a transmission that keeps running for 60 minutes after losing its lubricating oil^[34][35]. Lapping reduces friction between flanks and so reduces wear, vibration and noise; it is the same idea as the bevel gear lapping machine in Lancia's 1951 plan.

What we could not confirm. The history of gear makers for agricultural machinery (tractor) transmissions and axles, in-house gear making at motorcycle makers such as Ducati, and gear research at the Politecnico di Milano and the Università di Bologna could not be confirmed from primary sources, in dates or substance, in this study. We will add them as we learn more.

Links with Japan

Gear making in Japan and Italy followed the same path. Both imported American and German gear cutters in the first half of the 20th century, and after the war mass-produced car transmission gears by “hobbing → shaving → hardening.” In Japan shaving cutters had to be imported and few companies could regrind them, so in 1953 a Japanese tool maker began domestic production of shaving cutters under a technical tie-up with an American tool maker (Japanese Archive, Chapter 4, "The Lineage of Gear Cutting Machines"). In Italy, the tool company Samputensili offered in 1952 to build gear tools and machines under American license^[11], and the order of starting with tools and moving on to machines is also similar.

Samputensili set up a subsidiary in Japan in 1991 (later a sales and service office)^[6][23], and when it bought the Chemnitz plant in 2000, its Japanese base was counted as part of the group's production network^[24]. Japanese gear machine makers also began building shaving machines and gear grinders with their own technology from the 1970s (Japanese Archive, Chapter 4), and gear finishing machines became a field in which makers from Germany, Switzerland, Italy, the US and Japan compete.

FAQ

What kind of company is Samputensili?

A gear cutting tool company born in 1949 out of SAMP, a precision engineering company in Bologna. Its first customer was the Italian Air Force. It later built chamfering machines (1975), shaving cutter grinding machines (1977) and gear grinding machines (1988), and from 2000 to 2010 it also owned the hobbing machine plant in Chemnitz, Germany. In 2016 it split into a machine company and a tool company; the machines continue since 2021 as EMAG SU, part of Germany's EMAG, and the tools as Star SU Europe.

What is Star SU?

A 50/50 joint venture formed in 2002 when Samputensili's American subsidiary SU America and the Michigan tool maker Star Cutter combined their sales of gear cutting tools. At first it handled sales and service in North America; the partnership spread to South America in 2014, Asia in 2015 and Europe in 2022.

When did Samputensili buy Hurth Modul of Chemnitz?

In 2000. The two companies, which had sold jointly since 1998, became one, and spur and bevel gear hobbing machines joined Samputensili's range. In 2010 the hobbing machine business was sold to MAG of the US and became MAG Modul Verzahntechnik. The plant's history since 1900 is in the chapter on German gear machines.

What became of Sicmat, the shaving machine maker?

Sicmat of Torino built machine tools before the war, and after it sold machines to Fiat and to car factories in Europe and America as a specialist maker of shaving machines. In 2007 it entrusted North American sales to Star SU, and in 2015 it was bought by Samputensili, with production moving to Bentivoglio near Bologna. Its line continues today in EMAG SU.