Technikatörténeti szemle 11. (1979)
TANULMÁNYOK - Palágyi Gábor: A csavarról
GABOR PALÁGY: ON THE SCREN The origin of the screw is uncertain. As the legend goes the discovery of the screw was made by Archimedes and allegedly the vine tenderils gave him the idea. It is argued that in the Greek language the same word is used for the screw and for grape vine. Some people refer to Vittruvius Pollio and Plinius Gaius and maintain that the curved lines of the snail shell were the source the invention. The earliest record on the screw is foundin the work of Cato Marcus Porcius that appeared in 239 B. C. who described it as an important part of the vine and oil-press. Heron mentioned already a number of devices that utilized screws. In the Xlllth century the screw finds applications in armours, as a constituent of equipments. According to the testimony of different finds, the sharp-,rounded- and guns. In many drawings of Leonardo da Vinci the screw features as part of various flattened screw threads were equally known. It is quite possible that metal threads were produced by twisting an appropriate iron rod. This was the method used to make the Torques, the chains that were applied as military decoration. Many such finds were discovered in France and in England. These were probably by the skilful blacksmithes of the Celtic tribes, as well as the first screws were probably made by them by twisting rods of rectangular crossection. During the technical progress, the spreading of machinetools, traffic vehicles, et screw became increasingly indispensable The development of machine-tools rendered the making of screws easier. The Englishman Henry Maudslay had a prominent role in this respect.He devised a lathe that cloud be used for cutting threads. In the case of mass-produced screws it became apparent that these were rather different from one another. John Whitworth, wo had a machine factory in Manchester, recognized this disadvantage and proceeded to send his remarks to Institute of Civil Engineering. The June 15, 1841 issue of the Institution of Civil Engineers” gives an account of his conclusion: „The only efficient method for solving the problem is an agreement for the sake of mutual advantages, the interested parties accept a middle course. Such a compromise could be the mean pitch and depth of thread, as applied by the leading mechanical engineers forscrews. This measure not only could eliminate the general competition, but would also probably provide the true basis for the practical demands.” This proposition of Whitworth is, in fact, the first suggestion of standardization and it is generally regarded as the first step of industrial standardization. In the United States W. Sellers dealt with the problem of standardization of screws in 1864. An engineer from Baden, Delisl wrote a paper on the subject of „Thread systems for sharp screw threads” in 1873. Sauvage, a French railroad engineer, initiated in 1891 the standardization of various types of screws. Upon the suggestion and initiation of the Verein Schweizerische Machinenindust- rieller an international conference was held in Zurich in 1898, and the thread Sys- téme International was worked out. The International Federation of the National Standardization Associations wished to set down the unified dimensions of screws in the form of an international standard. This organization was formed in 1928. In present days the general solution of the problem is sought after in the frame of the International Organization of Standardization but the solution of this problem has not yet been achieved. 142
