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A router (, also ) is a tool used to rout out (hollow out) an area in the face of a relatively hard workpiece, typically of wood or plastic. The main application of routers is in woodworking, especially cabinetry. The router is most commonly used as a plunging tool and also inverted in a router table. The hand tool form of router is the original form. It is a specialized type of hand plane with a broad base and a narrow blade projecting well beyond its base plate (gaining it the nickname old woman's tooth). Today the power tool form of router, with an electric-motor-driven spindle, is the more common form, and the hand tool is now often called a ''router plane''. Although the hand tool has a few advantages over the power tool and retains favour with some workers, it has been mostly replaced by the modern spindle router, which was designed for the same work. Some workers consider it to be the single most versatile woodworking power tool.〔Broun 1989〕 Becoming more popular is the use of a CNC wood router, which implements the advantages of CNC (Computer Numerical Control). Related to the router is a smaller, lighter version designed specifically for trimming laminates. It can be used for smaller general routing work. For example, with an appropriate jig it can be used for recessing door hinges and recessing lock faceplates. Even rotary tools can be used as routers when the right bits and accessories (such as a plastic router base) are attached. ==History== Before power routers existed, the hand tool form was frequently used, especially by patternmakers and staircase makers. As early as 1905 the first commercially produced router — three phase and almost 60 pounds — was marketed by the Kelley Electric Machine Co. of Buffalo, New York. (New York Times, October 24, 1908, page 12.) George L. Kelley, a resident of Buffalo applied for a patent for a router in 1906; the patent was granted in 1908. The patent was assigned to Stevenson Machine Co. (By "assigned" is derived through "mesne", a technical term in law, meaning "middle" or "intermediate".) "Given the purported 1906 genesis of the Kelley Electric Machine Co., router", Keith Rucker speculates, "it is likely that Stevenson Machine Co. was a predecessor of Kelley Electric Machine Co." Kelley's patent claims that it is a "portable routing machine for working wood". Portable i.e., sixty pounds! ("portable" — in those days defined differently than today — meant that it can be "moved about" and "used on work benches, or elsewhere, where the work can be done to the best advantage". Also specified is that the machine can be operated "rapidly" and "accurately" by "unskilled labour". This machine, the patent's text continues, "is capable of a great variety of uses", including "cutting regular and irregular grooves or channels of different dimensions and shapes in the surfaces of boards". This machines is, especially, "suited to cutting grooves for stair stringers to receive the risers and treads". The innovation that Kelley's router achieved was to revolutionize the method of cutting the grooves. Mobile, the machine can be "moved about in any direction" and can be fitted with a "plurality of driven cutters" The pattern plate is adjustable to enable the cuts to be made in the desired location and relation on the work, and the pattern plate is also preferably provided with means for clamping or securing it on the work. Weighing sixty pounds, it is over 12" in diameter and 16" high. Keith Rucker〔http://www.owwm.com〕 notes that advertisements in the Wood-Worker between 1911 and 1929 show their "Kelley Router" - a handheld router that looks to be at least twice the size of any hand-held router available today. The bit rotates at 6500 RPM, roughly the slower speed of my two-speed shaper. Likely, at least in the beginning, the Kelley Router was powered by a "Direct Drive" motor. (Patent number 877894, granted in 1908) The first handheld power routers were invented in 1915〔(C.R. Onsrud History )〕 and were Jet Motor Hand Routers, called Onsruters. The name derives from a combination of the inventor's last name "Onsrud" and the term "router". The Onsruter married a router plane with an endmill to create the first handheld power router. The idea for the Onsruter started when a rail road company decided they wanted to power the front light on a Steam Locomotive using exhaust steam from the engine. Oscar Onsrud and his son Rudy came up with, and submitted, a design for a Jet Motor (air turbine) to generate the power for the light, however, they failed to win the contract. A few months later Rudy was talking with a friend about his frustrations making the groove in the bottom of a cane bottom chair using a router plane. A spark went off in Rudy's head that he could re-purpose the Jet Motor, which he had spent so much time developing, to run on compressed air and spin a modified endmill and make the routed groove easily. The modified endmills would have to spin at 30,000 RPM, instead of the 3,000 RPM of a milling machine, in order to cut wood and not burn it. These bits also needed a steeper rake and clearance angle to evacuate the chips than needed on a traditional endmill. These new bits became known as router bits. Further refinement produced the plunge router, invented by ELU (now part of DeWalt) in Germany in the late 1940s. This is even better adapted for many types of work. Starting in the 1960s, the power tool form of router became the more common form. Modern routers are often used in place of traditional moulding planes or spindle moulder machines for edge decoration (moulding) of timber. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Router (woodworking)」の詳細全文を読む スポンサード リンク
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