English mechanic and industrialist. He created a screw-cutting lathe with a mechanized support (1797), mechanized the production of screws, nuts, etc. early years spent in Woolwich near London. At the age of 12 he began working as a cartridge filler at the Woolwich Arsenal, and at the age of 18 he was the best blacksmith of the arsenal and a mechanic in the workshop of J. Bram, the best workshop in London. Later he opened his own workshop, then a factory in Lambeth. Created the Maudsley Laboratory. Designer. Mechanical engineer. He created a mechanized lathe support of his own design. I came up with an original set of replacement gears. Invented a cross-planing machine with a crank mechanism. Created or improved a large number of different metal-cutting machines. He built steam ship engines for Russia. Since the beginning of the 19th century, a gradual revolution in mechanical engineering began. The old lathe is being replaced one by one by new high-precision automatic machines equipped with calipers. The beginning of this revolution was laid by the screw-cutting lathe of the English mechanic Henry Maudsley, which made it possible to automatically turn screws and bolts with any thread.
The screw cutting machine designed by Maudsley represented a significant advance. The history of its invention is described as follows by contemporaries. In 1794-1795, Maudsley, still a young but already very experienced mechanic, worked in the workshop of the famous inventor Brahma. The main products of the workshop were water closets and locks invented by Bramo. The demand for them was very wide, and it was difficult to make them manually. Bramah and Maudsley were faced with the task of increasing the number of parts produced on the machines. However, the old lathe was inconvenient for this. Having begun work on its improvement, Maudsley equipped it with a cross support in 1794. The lower part of the support (slide) was installed on the same frame with the tailstock of the machine and could slide along its guide. In any place, the caliper could be firmly fixed with a screw. On the lower sled were the upper ones, arranged in a similar way. With their help, the cutter, fixed with a screw in a slot at the end of a steel bar, could move in the transverse direction. The caliper moved in the longitudinal and transverse directions using two lead screws. By moving the cutter using a support close to the workpiece, rigidly mounting it on a cross slide, and then moving it along the surface being processed, it was possible to cut off excess metal with great precision. In this case, the support performed the function of the worker’s hand holding the cutter. In fact, there was nothing new in the described design, but it was a necessary step towards further improvements.
Leaving Brahma soon after his invention, Maudsley founded his own workshop and in 1798 created a more advanced lathe. This machine was an important milestone in the development of machine tool construction, since for the first time it made it possible to automatically cut screws of any length and any pitch. As already mentioned, the weak point of the old lathe was that it could only cut short screws. It couldn’t be otherwise, because there was no support, the worker’s hand had to remain motionless, and the workpiece itself moved along with the spindle. In the Maudsley machine, the workpiece remained motionless, and the support with the cutter fixed in it moved. In order to make the caliper move on the lower slide along the machine, Maudsley connected the headstock spindle to the caliper lead screw using two gears. The rotating screw was screwed into a nut, which pulled the caliper slide behind it and forced it to slide along the frame. Since the lead screw rotated at the same speed as the spindle, a thread was cut on the workpiece with the same pitch that was on this screw. For cutting screws with different pitches, the machine had a supply of lead screws. Automatic screw cutting on the machine occurred as follows. The workpiece was clamped and ground to the required dimensions, without turning on the mechanical feed of the caliper. After this, the lead screw was connected to the spindle, and screw cutting was carried out in several passes of the cutter. Each caliper's return movement was done manually after turning off the self-propelled feed. Thus, the lead screw and caliper completely replaced the worker’s hand. Moreover, they made it possible to cut threads much more accurately and faster than on previous machines.
In 1800, Maudsley made a remarkable improvement to his machine - instead of a set of interchangeable lead screws, he used a set of interchangeable gears that connected the spindle and the lead screw (there were 28 of them with a number of teeth from 15 to 50). Now it was possible to obtain different threads with different pitches using one lead screw. In fact, if it was necessary, for example, to obtain a screw whose stroke is n times less than that of the lead screw, it was necessary to make the workpiece rotate at such a speed that it would make n revolutions during the time while the lead screw received its rotation from the spindle , this was easily achieved by inserting one or more gear wheels between the spindle and the screw. Knowing the number of teeth on each wheel, it was not difficult to obtain the required speed. By changing the combination of wheels, it was possible to achieve different effects, for example, cutting a right-hand thread instead of a left-hand one. On his machine, Maudsley cut threads with such amazing precision and accuracy that it seemed almost a miracle to his contemporaries. In particular, he cut the adjusting screw and nut for an astronomical instrument, which for a long time was considered an unsurpassed masterpiece of precision. The screw was five feet long and two inches in diameter with 50 turns for every inch. The carving was so small that it could not be seen with the naked eye. Soon, the improved Maudsley machine became widespread and served as a model for many other metal-cutting machines. Maudsley's outstanding achievement brought him great and well-deserved fame. Indeed, although Maudsley cannot be considered the only inventor of the caliper, his undoubted merit was that he came up with his idea at the most necessary moment and put it in the most perfect form.
His other merit was that he introduced the idea of the caliper into mass production and thereby contributed to its eventual spread. He was the first to establish that each screw of a certain diameter must have a thread with a certain pitch. Until screw threads were applied by hand, each screw had its own characteristics. Each screw had its own nut, which usually did not fit any other screw. The introduction of mechanized cutting ensured uniformity of all threads. Now any screw and any nut of the same diameter fit together, regardless of where they were made. This was the beginning of the standardization of parts, which was extremely important for mechanical engineering. One of Maudsley's students, James Nesmith, who later became an outstanding inventor himself, wrote in his memoirs about Maudsley as the pioneer of standardization. “He moved on to the spread of the most important matter of uniformity of screws. You can call this an improvement, but it would be more accurate to call it the revolution made by Maudsley in mechanical engineering. Before him, there was no system in the relationship between the number of threads of screws and their diameter. Every bolt and nut was suitable only for each other and had nothing in common with a bolt of adjacent sizes. Therefore, all bolts and their corresponding nuts received special markings indicating their belonging to each other. Any mixing of them led to endless difficulties and costs, inefficiency and confusion - part of the machine park should was constantly used for repairs. Only one who lived in the comparatively early days of machine manufacturing can have a correct idea of the troubles, obstacles and expenses which such a situation caused, and only one who will properly appreciate the great service rendered by Maudsley to mechanical engineering."
In fact, something similar was known in slave-owning Hellas several hundred years BC. The principle of obtaining bodies of rotation, in which it is necessary to rotate the workpiece by touching its surface with a stronger and sharper object, was easy to come up with.
There were no problems with the source of energy, since healthy and strong slaves were available in abundance. In more civilized times, such a machine was driven by a tightly stretched bowstring. But there was a significant limitation - the speed of revolutions fell as the bowstring untwisted, so in the Middle Ages models of foot-driven lathes appeared.
Design and principle of operation of a CNC lathe
They very vaguely resembled a sewing machine - because they included a traditional crank mechanism. This turned out to be a very positive change: the rotating workpiece now had no accompanying oscillatory movements, significantly complicating the work of the master and deteriorating the quality of processing.
However, by the beginning of the 16th century, the lathe still had a number of significant limitations:
- The cutter had to be held manually, so during prolonged metal processing the turner’s hand became very tired.
- The steady rest supporting long workpieces was attached separately from the machine, and therefore its installation and verification were quite lengthy.
- The problem of removing the chips was never solved: an apprentice was needed to periodically brush the chips off the master's hand.
- The issue of uniform movement of the cutter during processing was not resolved either: everything was determined by the qualifications and experience of the master.
The next few hundred years were spent designing a rotation drive for the moving center of the machine, in which the workpiece was mounted. The most successful was the design of Jean Besson, who was the first to use a water drive for these purposes.
The machine turned out to be quite cumbersome, but it was on it that threads were cut for the first time. This happened in the middle of the 16th century, and a few years later, Peter I’s mechanic Andrei Nartov invented a mechanized machine on which it was possible to cut threads with a variable speed of rotation of the moving center. A characteristic feature of Nartov’s machine was also the presence of a replaceable gear block.
Who invented the caliper?
The support is the key component of a modern lathe; everything else could, to one degree or another, be borrowed from other mechanisms. At the same time, having a device for precise movement of a metal-cutting tool along the surface being processed, and in all three coordinates, one could talk about a fully functional machine for turning. But, as in most other cases from the history of technology, it is impossible to establish sole authorship in the invention of the caliper.
What does it say about Andrei Nartov’s priority?
- A self-propelled support appeared in Nartov's copying machine in 1712, while Henry Maudsley introduced his version only in 1797.
- For the first time, the joint movement of the copier and the support in the Nartov version of the machine was carried out using one mechanism - a lead screw.
- Changing the cross-feed speed was technically ensured by different thread pitches on the lead screw.
The term “support” (from the French word support - support) was first introduced into use by Charles Plumet, and the machine built by his compatriot Jean Vaucanson was practically similar to the one with which all turners now work.
This mechanism had V-shaped guides that were accurate for its time, and the caliper had the ability to move not only in the transverse, but also in the longitudinal directions. However, not everything was in order here either - in particular, there was no chuck where the workpiece to be processed would be secured.
This significantly narrowed the technological capabilities of the equipment: for example, turning of workpieces that had different lengths was impossible. And in general, perform any other operations other than cutting threads on screws, bolts, etc.
And then Henry Maudsley appears on the historical stage.
Universal lathe – the time has come
In many branches of human creative activity, the palm goes to the one who not only invented something, but was also able to analytically correctly generalize the experience of previous generations. Henry Maudsley is no exception.
There is no reason to claim that Maudsley simply stole the caliper circuit from Andrey Nartov. Yes, during the time of Peter I, ties with England were not particularly welcomed, but relations with Holland were strong. But given the fact that the Dutch, in turn, often hosted English entrepreneurs and simply craftsmen, it is likely that Nartov’s invention very soon became known on the shores of Foggy Albion (although Maudsley himself could have learned about Nartov’s machine, since in those years he was engaged in construction steam engines For Russia).
The greatness of Henry Maudsley lies elsewhere - he introduced interested parties to the court (and in England by that time the industrial revolution was underway full swing) the concept of the first truly universal machine for performing various turning operations. Equipment in which all the problems of the turning method of processing products were organically solved.
Maudsley's first caliper had a cross-shaped design: there were two lead screws to move along the guides. But in 1787, Maudsley radically changed the order of movements of the tool and the workpiece: the latter remained motionlessly fixed, and the caliper now slid along its generatrix. To implement this change, Maudsley connected one of the caliper lead screws to the headstock using a gear drive (a nuance that Nartov had not thought of). As a result, thread cutting began to be performed automatically, and only the support was removed manually after processing the part.
By later adding a set of replaceable gears to the machine, Maudsley achieved what is now inherent in any lathe - versatility and technological ease of operation.
Video: Operating a lathe
A lathe is a machine for processing by cutting (turning) workpieces made of metals, wood and other materials in the form of bodies of rotation. On lathes, turning and boring of cylindrical, conical and shaped surfaces, thread cutting, trimming and machining of ends, drilling, countersinking and reaming of holes, etc. are performed. The workpiece receives rotation from the spindle, the cutter - the cutting tool - moves along with the slide of the support from lead shaft or lead screw receiving rotation from the feed mechanism.
In the XVII-XVIII centuries. The manufacturing industry developed rapidly. Many manufactories had metalworking workshops.
Processing in the workshops was carried out mainly on bow lathes. In these machines, a flexible pole was fixed on top, to which one end of the rope was tied. The rope wrapped around the roller on the machine. The other end was attached to a board, which acted as a pedal for the worker's foot. By pressing the pedal, the worker rotated the roller and the workpiece. He held the cutting tool in his hand. The lathe was a complex tool, but not a machine. To transform into a machine, a tool holder-support was needed, replacing a human hand.
The inventor of the lathe with a caliper was the Russian mechanic A.K. Nartov. He built several turning and copying machines that had a mechanical support holder.
On the machines designed by Nartov, a wheel driven by water or animal power could be used for drive.
Despite Nartov’s remarkable work and the high appreciation that his inventions and knowledge received, the support he invented did not have much influence on the practical development of turning technology.
At the end of the 18th century. The idea of using supports in lathes was returned to in France. In Diderot's "French Encyclopedia" in 1779, a description of a device for lathes is given, which clearly resembles the principle of a support. However, these machines had a number of disadvantages that precluded their widespread use in practice.
The opportunity to develop mechanical engineering technology appeared only as a result of the first two stages of the industrial revolution. For machine production of machines it was necessary powerful engine. By the beginning of the 19th century. The universal double-acting steam engine became such an engine. On the other hand, the development of the production of working machines and steam engines in the second half of the 18th century. formed qualified personnel for mechanical engineering - mechanical workers. These two conditions ensured the technical revolution in mechanical engineering.
The change in machine manufacturing technology began with the English mechanic Henry Maudsley, who created a mechanical support for a lathe. Maudsley began working at the London Arsenal at the age of twelve. There he acquired good skills in wood and metalworking and, in addition, became a master blacksmith. However, Maudsley dreamed of a career as a mechanic. In 1789, he entered the London mechanical workshop of Joseph Bram, a specialist in the manufacture of locks.
In Bram's workshop, G. Maudsley had the opportunity to invent and design various devices for making locks.
In 1794, he invented the so-called cross support for a lathe, which contributed to the transformation of the machine into a working machine. The essence of Maudsley's invention boiled down to the following: turners, turning an object, tightly secured it on the machine with special clamps. The working tool - the cutter - was in the hands of the worker. When the shaft rotated, the cutter processed the workpiece. The worker had to not only create the necessary pressure with the cutter on the workpiece, but also move it along it. This was only possible with great skill and great tension. The slightest displacement of the cutter disrupted the precision of turning. Maudsley decided to strengthen the cutter on the machine. To do this, he created a metal clamp - a caliper, which had two carriages moving by means of screws. One carriage created the necessary pressure of the cutter on the workpiece, and the other moved the cutter along the workpiece. Thus, the human hand was replaced by a special mechanical device. With the introduction of the support, the machine began to operate continuously with a perfection unattainable even by the most skillful human hand. The caliper could be used for the manufacture of both the smallest parts and huge parts of various machines.
This mechanical device replaced not any tool, but the human hand, which creates a certain shape by bringing it closer, applying the tip of a cutting tool, or directing it to the material of labor, for example, wood or metal. Thus, it was possible to reproduce the geometric shapes of individual parts of machines with such ease, accuracy and speed that the hand of the most experienced worker could never have been achieved.
The first machine with a support, although extremely imperfect, was manufactured in Bram's workshop in 1794-1795. In 1797, Maudsley built the first working lathe on a cast iron bed with a self-propelled slide. The machine was used for cutting screws and was also used for processing parts of locks.
Subsequently, Modesi continued to improve the lathe with a caliper. In 1797, he built a screw-cutting lathe with a replaceable lead screw. Making screws in those days was extremely difficult work. The hand-cut screws had a completely random thread. It was difficult to find two identical screws, which made it extremely difficult to repair machines, reassemble them, and replace worn-out parts with new ones. Therefore, Maudsley primarily improved screw-cutting lathes. Through his work on improving screw threading, he achieved partial standardization of screw manufacturing, paving the way for his future student Whitworth, the founder of screw standards in England.
The simplest lathe
The Maudsley self-propelled lathe, offered for screw cutting work, soon proved to be an indispensable machine in any turning job. This machine worked with amazing precision, without requiring much physical effort on the part of the worker.
Attempts to create a working machine in mechanical engineering since the end of the 18th century. were also done in other countries. In Germany, the German mechanic Reichenbach, independently of Maudsley, also proposed a device for holding a cutter (support) on a wooden lathe designed for processing precision astronomical instruments. However, the economic development of feudal Germany lagged far behind the development of capitalist England. The mechanical support of the handicraft German industry was not needed, while the introduction of the Maudsley screw-cutting lathe in England was due to the needs of developing capitalist production.
The caliper was soon developed into a perfect mechanism and, in a modernized form, was transferred from the lathe for which it was originally intended to other machines used in the manufacture of machines. With the manufacture of supports, all metalworking machines begin to improve and turn into machines. Mechanical turret, grinding, planing, and milling machines appear. By the 30s of the XIX century. English mechanical engineering already had basic working machines that made it possible to perform mechanically the most important operations in metalworking.
Soon after the invention of the caliper, Maudsley left Brahm and opened his own machine shop, which quickly grew into a large engineering plant. The Maudsley plant played an outstanding role in the development of English machinery. It was a school of famous English mechanics. Such outstanding mechanical engineers as Whitworth, Roberts, Nesmith, Clement, Moon and others began their activities here.
At the Maudsley plant, a machine production system was already used in the form of connecting through transmissions a large number of working machines driven by a universal heat engine. The Model Factory mainly produced parts for Watt's steam engines. However, the plant also designed working machines for mechanical workshops. G. Maudsley produced exemplary lathes and then planing mechanical machines.
Model himself, despite the fact that he was the owner of a large enterprise, worked all his life along with his workers and students. He had an amazing ability to find and train talented mechanical engineers. Many eminent English mechanics owe their technical education to Maudsley. In addition to the caliper, he made many inventions and improvements in a wide variety of branches of technology.
General view of the lathe
On a rigid base 1, which is called the bed, the headstock 5 and tailstock 2 are fixed. The headstock is fixed. Its main unit is the spindle shaft 8. It rotates in bronze bearings inside a fixed housing 7. A device for fastening the workpiece is installed on the spindle. In this case, this is fork 9. To clamp the part, depending on its size and shape, a faceplate, chuck and other devices are also used. The spindle rotates from an electric motor 10 through a drive pulley 6.
The tailstock of the machine can move along the bed and is fixed in the desired position. At the same level with the headstock spindle, the so-called center 11 is installed in the tailstock. This is a roller with a pointed end. The tailstock is used when processing long parts - then the workpiece is clamped between the spindle fork and the center of the tailstock.
A modern lathe consists of working parts - a support for fastening the cutter, a spindle for fastening the part, a motor and a transmission that transmits movement from the motor to the spindle. The transmission consists of a gearbox and a gearbox. The gearbox is a set of shafts with gears attached to them. By switching gears, they change the spindle speed, leaving the engine speed unchanged. The gearbox transmits rotation from the gearbox to the lead shaft or lead screw. The lead roller and lead screw are designed to move the support on which the cutter is attached. They allow you to match the speed of the cutter with the rotational speed of the part. The lead roller sets the metal cutting mode, and the lead screw sets the thread pitch.
The headstock and tailstock serve as support for the spindle, tool, or attachments.
All machine components are attached to the bed.
Henry Maudsley(English Henry Maudslay; August 22, 1771 - February 14, 1831) - British inventor of tools, dies and machines, considered one of the creators of the screw-cutting lathe.
Childhood years of life
Maudsley's father, also named Henry, worked as a wheel and coach repairman for the Royal Engineers. After being wounded in action, he became a storekeeper at the Royal Arsenal, based in Woolwich, south London, a factory that manufactured arms, ammunition and explosives and carried out scientific research for the British armed forces. There he married a young widow, Margaret Londy, and they had seven children, of whom young Henry was the fifth. In 1780, Henry's father died. Like many children of the era, Henry began working in manufacturing from an early age, at the age of 12 he was a "powder monkey", one of the boys hired to fill cartridges at the Royal Arsenal. Two years later he was transferred to the carpentry shop , equipped with a stamping forge press, where at the age of fifteen he began to learn the blacksmith's craft.
Career
In 1800, Maudsley developed the first industrial metal-cutting machine to standardize thread sizes. This allowed the concept of interchangeability to be introduced to put nuts and bolts into practice. Before him, threads, as a rule, were filled by skilled workers in a very primitive way - they marked a groove on the bolt blank, and then cut it using a chisel, a file and various other tools. Accordingly, the nuts and bolts turned out to be of non-standard shape and size, and such a bolt fit exclusively to the nut that was made for it. Nuts were rarely used; metal screws were used mainly in woodworking to connect individual blocks. Metal bolts passing through the wood frame were jammed on the other side for fastening, or a metal washer was put on the edge of the bolt, and the end of the bolt was flared. Maudsley standardized the thread making process for use in his workshop and produced sets of taps and dies so that any bolt of the appropriate size would fit any nut of the same size. This was a big step forward in technological progress and equipment production.
Maudsley first invented a micrometer with a measurement accuracy of one ten-thousandth of an inch (0.0001 in 3 microns). He called it "Lord Chancellor" because it was used to settle any questions regarding the accuracy of the measurements of parts in his workshops.
In his old age, Maudsley developed an interest in astronomy and began building a telescope. He intended to buy a house in one of the areas of London and build a private observatory, but he fell ill and died before he could carry out his plan. In January 1831, he caught a cold while crossing the English Channel while returning from visiting a friend in France. Henry was ill for 4 weeks and died on February 14, 1831. He was buried in the parish cemetery of St. Mary Magdalene in Woolwich (South London), where a cast-iron memorial to the Maudsley family, cast at a factory in Lambeth, was erected to his design. Subsequently, 14 members of his family were buried in this cemetery.
Many distinguished engineers trained in Henry's workshop, including Richard Roberts, David Napier, Joseph Clement, Sir Joseph Whitworth, James Nasmith (inventor of the steam hammer), Joshua Field and William Muir.
Henry Maudsley contributed to the development of mechanical engineering when it was still in its infancy, his main innovation was in the creation of machine tools that would later be used in technical workshops around the world.
The Maudsley Company was one of the most important British engineering manufactories of the nineteenth century and existed until 1904.
Literature
- John Cantrell and Gillian Cookson, eds., Henry Maudslay and the Pioneers of the Machine Age, 2002, Tempus Publishing, Ltd, pb., (ISBN 0-7524-2766-0)
- Henry Maudsley / F. N. Zagorsky, I. M. Zagorskaya, Publisher: Nauka - 1981 - 144 pp.,