Volume 4 | Issue 1 | Year 2001

In 1938 Bridgeport Machines, Inc., revolutionized machine-tool technology with its invention of an extraordinary milling machine featuring a revolving turret with a head that traversed the full length of the table. The Series 1 Standard machine provided unheard-of productivity and versatility at a price that every machine shop could afford, even in those trying times.

Over the years, Bridgeport has continued to set the standard for milling machines, and has expanded to provide a wide range of other machining innovations. Today, it is a leading manufacturer and marketer of computer-numerically controlled (CNC) machining and turning centers, and manual and automatic mills, lathes and surface grinders.

Powerful Combination
In 1999, Bridgeport Machines became the dominant component of the Goldman Industrial Group of Boston, comprised of several leading machine-tool manufacturers that have set quality standards within their respective industries and technologies. Combined, the Goldman Group has an installed base of more than 400,000 highly engineered machines throughout the world.

Following the acquisition, Goldman completely restructured Bridgeport’s management at its Bridgeport, Conn., headquarters, with an emphasis on globalization and innovation. Bridgeport now faces the world market as one company with group executives and product managers, rather than with the previous fragmented chain of command.

The North and South American markets are served from the Bridgeport headquarters and plant and another factory in Elgin, Ill., while the headquarters for European operations is at a former Adcock & Shipley plant in Leicester, England. A state-of-the-art components plant in Kempten, Germany, serves as an adjunct to Leicester. The firm has about 800 employees at these sites and various sales and service facilities. Both Bridgeport and Leicester are ISO 9001-certified.

Supplier Extraordinaire
Bridgeport Machines, Inc., was presented with the American Machinist 2000 Excellence in Manufacturing Technology Achievement Award for Performance and Repeatability on the eve of the International Manufacturing Technology Show (IMTS) in Chicago. The American Machinist awards were established to recognize extraordinary vendors of manufacturing equipment and production supplies. They were based on a series of surveys conducted between March and May 2000, in which American Machinist subscribers indicated their choices of outstanding vendors for design and productivity, flexible solutions, innovations, performance and repeatability, technology and reliability, service and technical support, and user-friendliness.

IMTS 2000 was the site chosen by Bridgeport Machines for the introduction of several significant technological advances. The revolutionary FGC-1000 Flexible Grinding Center with the VIPER process was an eye-catcher at the show. The new machine, built at the Leicester factory, incorporates creep-feed grinding on a machining center. It is a full five-axis production machining center fitted with a special coolant delivery system and a 30-tool changer table to store 4.7-inch to 8.7-inch (120-millimeter to 220-millimeter) diameter grinding wheels. The VIPER process, which stands for “Very Impressive Performance, Extreme Removal,” makes it possible to integrate grinding with milling techniques for total flexibility. VIPER also saves on multiple machine setups, reduces manpower costs, lowers consumable costs and increases accuracy.

Patented by Rolls-Royce PLC, the concept is the result of a partnership between Rolls-Royce Mantech Division and a core of specialist companies. Bridgeport Machines is one of only three machine builders worldwide that have been licensed by the aerospace division of Rolls-Royce after completion of a five-year development program. Bridgeport Machines plans to offer machines, such as the FGC-1000, that use this special process for turbine blade production, an important function in the aerospace industry.

The FGC-1000 uses standard oxide-based grinding wheels to extremely good effect. Stock removal rates can be up to eight times that of the more expensive CBN wheel-equipped machines. This is especially economical when machining the high-nickel alloys used in gas turbine blade manufacture.

Other advantages of the FGC-1000 are high rigidity, high rapid rates, fast processing times, high feed rates and the ability to change tools in cycle. Bridgeport Machines’ exhibit also emphasized adaptive fixturing methods that allow more features to be ground in one setting, reducing operations and increasing accuracy. The entire process is made easier for use on the shop floor by incorporating specialized grinding cycles into the Heidenhain TNC 426 control.

Also introduced at IMTS 2000 was Bridgeport Machines’ new pendant arm on its EZTRAK automated knee mill. The show exhibit demonstrated the EZTRAK mill’s flexibility, productivity and economy – qualities needed by machine shops for efficent production of single parts, prototypes and small runs. Ideal for tool rooms and job shops, the EZTRAK mill can increase productivity fourfold over manual knee mills, according to Bridgeport Machines literature. The new fully articulated pendant arm enhances operator comfort and ease of use, and features a full alphanumeric keypad. A 9.72-inch color liquid-crystal-display (LCD) flat screen provides a 22 percent larger display than previously available, and allows clearer viewing of part-input screens and cut-path displays. The PC-based control allows both programmed and manual milling, and provides common milling and drilling routines, bolt-hole patterns and a two-dimensional contouring capability that allows operators to machine angles and radii without attachments.

Partnership for Progress
Bridgeport Machines’ turning line has been expanded by a partnership project with Okuma America Corporation, a leading manufacturer of CNC lathes, that has produced a new line of turning centers, which were also unveiled at IMTS 2000. The HTC-6 and HTC-8 models will be manufactured exclusively for Bridgeport Machines by Okuma, and will offer a host of features designed to support production turning applications including rigid slant-bed construction, 787 inches-per-minute rapid transverse rate for stable, accurate turning, a complete coolant system and an automatic lubrication system.

The turning centers feature a powerful GE/Fanuc 21i control that is integral to the operator panel. A color LCD display with preconfigured screens allows program and ladder monitoring/editing, alarm/operation history and periodic maintenance. The control features a dedicated PMC processor for ladder execution and an all-digital servo loop using a unique Fanuc Serial Servo Bus (FSSB), with a fiber-optic connection to the alpha servomotors that provides high resistance to environmental noise for increased machine up time. A PCMCIA card slot yields fast upload and download capabilities.