There are more than 4,300 years between the invention of a threaded screw and the modern industrial threaded screw as it is known nowadays. That's a long period of time since the threaded screw is something the majority of the world doesn't spend much time thinking about. Every time you turn a screwdriver in the process of making something, you can thank thousands of years of innovation. And the next time you use an object (car, washer, TV…), whether screws were used to manufacture the object itself or used in the machinery that made that object, you will think about this article.
Archimedes and the First Screw Design
The concept of the screw as a tool is thought to have been invented by Archimedes sometime between the years 287 B.C., and 212 B.C. He is considered one of the best scientists in the age of antiquity. He dedicated all his life to science, actually, his dedication got him killed when we was captured during war. Archimedes Screw was a device used first and foremost to bail water out of boats.
The Real Deal
Producing alcohol was one of the first places threaded screws appeared as tools. Massive screws were used to squeeze juices from grapes to make wine, and also to make oil from olives. These old threaded screws have been found in archaeological digs in Pompeii and in many other cities and countries around the world. Threaded screws were used as well by the Romans as medicinal presses, odometers and much more.
After the classical era, the screw wasn't really used anymore. No major inventions were made from the threaded screw until the 15th century were it reappeared on boats design.
However, up until the 18th century, threaded screws were made by hand and the accuracy of the job was highly contingent on the workers' skills. Sometime around the middle of that same century, the need for precise screw threads became miportant. A French clockmaker, named Antoine Thiout, designed and assembled the first machine tool equipped with a screw drive. 20 years later, Jesse Ramsden came along with a new design and created the first satisfactory screw-cutting lathe.
The Industrial Revolution
The lack of standardization made screws interchangeability problematical. To overcome these difficulties Joseph Whitworth collected sample screws from different British workshops and came to the following conclusions:
- The angle the thread flanks should be standardized at 55 degrees
- The number of threads per inch should be standardized for various diameters.
His conclusions became standard practice in Britain in the late 19th century and open the era of the modern screw as know today. Nevertheless, manufacturing is constantly come up with new applications for threaded screws. So as long as there is technological improvement, there will always be a necessity for new screw types.
Importance of Threaded Screws in Modern Manufacturing
Practically everything would fall apart if all the screws on the planet just vanished. Although we don't think much about it, we are very reliant on the threaded screw and everything it has helped us accomplish.
It has become such an important part nowadays that the International Organization for Standardization has set up precise specifications for screws (ISO 68-1). The profile of modern screw is engineer using a series of equation to define the perfect the height of each thread with the pitch. More details: http://en.wikipedia.org/wiki/ISO_metric_screw_thread
Screws in Indelac Actuators
Indelac uses screws to build all its products and at all stages of the manufacturing processes. The smaller electric actuator (R Series) counts a total 11 screws and the larger one (27K) is assembled using 57 screws. Screws of different diameter (from 0.1" to more than 0.31"), length (from ¼" to 3.75") and head (round, phillips socket) are used. For purposes of quality control, reliability and deliveries, ICI gets its screws from a Cincinnati based supplier.
See original article: http://blog.indelac.com/bid/339867/History-of-Threaded-Screws-Small-but-Vital-Component-of-an-Actuator