ThermoGrip Technology The Pioneers of High-tech Toolholding The Marquart Sto ry As milling machines evolved, with higher speed, more power and multi-axis milling capability, toolholder technology was forced to evolve as well. Out of the numerous systems introduced and then forgotten, ThermoGrip HeatShrink Technology (THT) has remained the standard of the industry. The pioneer in the development of ThermoGrip HeatShrink Technology was Marquart, of Reichenbach, Germany. The innovators at Marquart recognized the need for a new type of toolholder early on. From this recognition, and driven by the forces of developing machine-tool technology, came ThermoGrip HeatShrink Technology. After the development of NC technology, not too much changed in the machine-tool world. Spindles that ran at 2000 RPM were the norm, and 5000 RPM was considered breathtaking speed. It was not until the advent of CNC technology, and the processors needed to exploit it, that machine-tools really began to change. The 90 s were marked by many innovative machine concepts. Multi-axis milling with integrated rotary-tables became more sophisticated. The accuracy of the machines improved constantly, to the point where they are now capable of jigmill accuracy. In recent years, High Speed Cutting (HSC) has raised the bar for the development of new tooling.. Today the best machines will cut a circular pocket accurate within microns, and do so at previously unheard of speeds. This is a real challenge for toolholder and cutting tool manufacturers. The 40 micron double-fluted cutter, is now working reality. This opens up great opportunities for new cutting strategies to deal with exotic materials or to micromanufacture products. But, back to the pioneer, Marquart. Initially, the idea was to exploit the thermal expansion of metals in order to introduce a cutting tool into a toolholder. The company first built a jig in which the tool holder was clamped, and the cutting tool was mounted in a spring-loaded adapter. As the toolholder was rotated in the jig, an open flame heated the tip of the toolholder until it had opened sufficiently for the cutting tool to be inserted. There was no provision for cooling the assembly, so there was a rather long wait for it to cool down enough to be handled. Shrink wrapping machine with welding torch The next stage in the development of THT was a vertical machine that basically used a blowdryer to heat the nose of the toolholder. Because the tools were held vertically, Marquart improved the process with the introduction of the "Vorweite", or Opening Cylinder. This was simply a slightly oversized diameter at the mouth of the bore which allowed the cutting tool to
be started. When the toolholder nose was heated and the bore expanded, the cutting tool would slide into place under its own weight. Vertical Shrink unit Maquart patented this Opening Cylinder technology, and today the partners of ThermoGrip Group maintain it. Several manufacturers of HeatShrink toolholders are licensed by the ThermoGrip Group to produce toolholders using this technology. Relieved bore, opening cylinder The ThermoGrip Group is Formed In 2000, after earlier, informal contacts between different companies manufacturing HeatShrink technology, Representatives of Marquart, Bilz, Diebold and Komet agreed to cooperate in the development and improvement of HeatShrink technology. Each of these companies had patents in this field, and by consigning these patent rights to a new group, the members of the group could focus on R&D and avoid costly patent disputes and simplify licensing. As a result, the ThermoGrip Group was founded, consisting of Marquart, Diebold, Bilz, and Komet. Since then, R&D work has been pooled and shared freely to benefit the industry, and ultimately, the end-user. Shortly after the founding of the ThermoGrip Group, the first induction units were offered. Inductant heatshrink is, simply put, using a shielded magnetic field to heat the nose of the toolholder just enough to allow the cutting tool to be inserted.
To ensure the safety of the operator by eliminating stray voltage and magnetic flux, all of the magnetic coils on ThermoGrip Group inductant machines are shielded by a proprietary device. The ThermoGrip Group holds the patent to this shielding device, even after repeated attempts by competitors to defeat it. Machines that are not shielded in this manner may be extremely hazardous to the health of the operator and anyone else in the vicinity. Coil with pole ring Since the founding of the ThermoGrip Group there has been a continuous stream of new ThermoGrip ShrinkFit technology. The Marquart E-Two and the Diebold MS 502 are horizontal designs, and the Bilz ISG series of machines are vertical designs. Diebold introduced water-cooling to ThermoGrip with its patented FKS series of cooling stations, and Bilz has perfected a fully-automated system of heating and cooling the toolholders for nearinstant use. E-Two, ISG3202WK, MS 502 In 2005, Uwe Marquart decided to sell his company, Marquart, to an investor. In 2008, the investor dissolved the company. Diebold purchased Marquarts ShrinkFit program and all its associated patents, and the rights to the brand name Pyroquart. In addition, Diebold hired Marqaurts experienced design team. This product line was subsequently expanded and integrated into the ThermoGrip sales program. Pyroquart has a short overall length for stability, resulting in a toolholder with increased clamping and higher retention forces toolholders produced to the DIN Standard. Pyroquart is the ideal ThermoGrip toolholder for high speeds and feeds and heavy loads.
E-TWO with PYROquart chucks The Marquart Pyroquart line for High Productivity Cutting (HPC) With the advent of High-Speed Cutting (HSC), toolholders with extremely thin wall crosssections were required. In response, Diebold developed the MS 502, a low-energy, programmed-pulse inductant unit to reliably heat these smaller toolholders without damaging them. By taking advantage of the years of combined R & D programs, the ThermoGrip Group has been able to offer these and other fine ThermoGrip ShrinkFit products. MS 502 with air chiller and tools Diebold is an innovator in the manufacture of toolholders and high-frequency spindles. Not content to play catch-up, Diebold recently introduced it s patented JetSleeve system. JetSleeve uses an aluminum sleeve with several coolant outlets to introduce coolant, MQL, or air-blast directly to the tool-tip during machining. As the cutter advances, chips are continuously blown-out of the work area, eliminating cutter damage and chatter, even in the deepest cavities.
JetSleeve The newest product line, introduced at EMO 2011 by the ThermoGrip Group are ThermoER (TER) collets. Based on an idea patented by Marquart and perfected by the ThermoGrip Group, TER collets yield vastly improved rigidity and repeatability over standard ER collets. TER Collets + Adapter, Live Tool for lathe with TER collet The ThermoGrip Group is constantly striving for technological advancement in the ShrinkFit field and in strengthening its position as a technological leader. With continuous improvements in equipment technology, enhancements to the toolholders and accessories, we help to ensure that you achieve the highest production value possible. Hermann Diebold, C.E.O., Diebold GmbH & Co.
The Diebold factory