The Browning Hi Power is a single-action, semi-automatic handgun available in the 9mm and.40 S&W calibers. It is based on a design by American firearms inventor John Browning, completed by Dieudonné Saive at Fabrique Nationale of Herstal, Belgium. Browning died in several years before the design was finalized; the Hi-Power is one of the most used military pistols in history, having been used by the armed forces of over 50 countries. After 82 years of continuous production, the Hi-Power was discontinued in 2017 by Browning Arms, but it remains in production under license; the Hi Power name alludes to the 13-round magazine capacity twice that of contemporary designs such as the Luger or Colt M1911. The pistol is referred to as an HP, GP, BAP, or BHP; the terms P-35 and HP-35 are used, based on the introduction of the pistol in 1935. It is most called the "Hi Power" in Belgium; the Browning Hi-Power was designed in response to a French military requirement for a new service pistol, the Grand Rendement, or alternatively Grande Puissance.
The French military required that: the arm must be compact the magazine have a capacity of at least 10 rounds the gun have a magazine disconnect device, an external hammer, a positive safety the gun be robust and simple to disassemble and reassemble the gun be capable of killing a man at 50 metresThis last criterion was seen to demand a caliber of 9 mm or larger, a bullet mass of around 8 grams, a muzzle velocity of 350 m/s. It was to accomplish all of this at a weight not exceeding 1 kg. FN commissioned John Browning to design a new military sidearm conforming to this specification. Browning had sold the rights to his successful M1911 U. S. Army automatic pistol to Colt's Patent Firearms, was therefore forced to design an new pistol while working around the M1911 patents. Browning built two different prototypes for the project in Utah and filed the patent for this pistol in the United States on 28 June 1923, granted on 22 February 1927. One was a simple blowback design. Both prototypes utilised the new staggered magazine design to increase capacity without unduly increasing the pistol's grip size or magazine length.
The locked breech design was selected for further testing. This model was striker-fired, featured a double-column magazine that held 16 rounds; the design was refined through several trials held by the Versailles Trial Commission. In 1928, when the patents for the Colt Model 1911 had expired, Dieudonné Saive integrated many of the Colt's patented features into the Grand Rendement design, in the Saive-Browning Model of 1928; this version featured the removable barrel bushing and take down sequence of the Colt 1911. By 1931, the Browning Hi-Power design incorporated a shortened 13-round magazine, a curved rear grip strap, a barrel bushing, integral to the slide assembly. By 1934, the Hi-Power design was ready to be produced, it was first adopted by Belgium for military service in 1935 as the Browning P-35. France decided not to adopt the pistol, instead selecting the conceptually similar but lower-capacity Modèle 1935 pistol; the Browning Hi-Power has undergone continuous refinement by FN since its introduction.
The pistols were made in two models: an "Ordinary Model" with fixed sights and an "Adjustable Rear Sight Model" with a tangent-type rear sight and a slotted grip for attaching a wooden shoulder stock. The adjustable sights are still available on commercial versions of the Hi-Power, although the shoulder stock mounts were discontinued during World War II. In 1962, the design was modified to replace the internal extractor with an external extractor, improving reliability. Standard Hi-Powers are based on a single-action design. Unlike modern double-action semi-automatic pistols, the Hi-Power's trigger is not connected to the hammer. If a double-action pistol is carried with the hammer down with a round in the chamber and a loaded magazine installed, the shooter may fire the pistol either by pulling the trigger or by pulling the hammer back to the cocked position and pulling the trigger. In contrast, a single-action pistol can only be fired with the hammer in the cocked position. In common with the M1911, the Hi-Power is therefore carried with the hammer cocked, a round in the chamber and the safety catch on.
The Hi-Power, like many other Browning designs, operates on the short-recoil principle, where the barrel and slide recoil together until the barrel is unlocked from the slide by a cam arrangement. Unlike Browning's earlier Colt M1911 pistol, the barrel is not moved vertically by a toggling link, but instead by a hardened bar which crosses the frame under the barrel and contacts a slot under the chamber, at the rearmost part of the barrel; the barrel and slide recoil together for a short distance but, as the slot engages the bar, the chamber and the rear of the barrel are drawn downward and stopped. The downward movement of the barrel disengages it from the slide, which continues rearward, extracting the spent case from the chamber and ejecting it while re-cocking the hammer. After the slide reaches the limit of its travel, the recoil spring brings it forward again, stripping a new round from the magazine and pushing it into the
Gas-operation is a system of operation used to provide energy to operate locked breech, autoloading firearms. In gas operation, a portion of high-pressure gas from the cartridge being fired is used to power a mechanism to dispose of the spent case and insert a new cartridge into the chamber. Energy from the gas is harnessed through either a port in a trap at the muzzle; this high-pressure gas impinges on a surface such as a piston head to provide motion for unlocking of the action, extraction of the spent case, cocking of the hammer or striker, chambering of a fresh cartridge, locking of the action. The first gas-operated rifle was designed in 1883–1884 by Karel Krnka. Most current gas systems employ some type of piston; the face of the piston is acted upon by combustion gas from a port in the barrel or a trap at the muzzle. Early guns such as Browning's'flapper' prototype, the Bang rifle, Garand rifle used low-pressure gas from at or near the muzzle. This, combined with larger operating parts, reduced the strain on the mechanism.
To simplify and lighten the firearm, gas from nearer the chamber needed to be used. This high-pressure gas has sufficient force to destroy a firearm. Most gas-operated firearms rely on tuning the gas port size, mass of operating parts, spring pressures to function. Several other methods are employed to regulate the energy; the M1 carbine incorporates a short piston, or "tappet". This movement is restricted by a shoulder recess. Excess gas is vented back into the bore; the M14 rifle and M60 GPMG use the White expansion and cutoff system to stop gas from entering the cylinder once the piston has traveled a short distance. Most systems, vent excess gas into the atmosphere through slots, holes, or ports. A gas trap system involves ` trapping' combustion gas; this gas impinges on a surface that converts the energy to motion that, in turn cycles the action of the firearm. Hiram Maxim patented a muzzle-cup system in 1884 described in U. S. Patent 319,596 though it is unknown if this firearm was prototyped.
John Browning used gas trapped at the muzzle to operate a'flapper' in the earliest prototype gas-operated firearm described in U. S. Patent 471,782; the Danish Bang rifle used a muzzle cup blown forward by muzzle gas to operate the action through transfer bars and leverage. Other gas-trap rifles were early production German Gewehr 41; these systems are longer, heavier and more complex than gas-operated firearms. Despite these disadvantages, they used low pressure gas and did not require a hole in the barrel; the American and German governments both had requirements that their guns operated without a hole being drilled in the barrel. Both governments would first adopt weapons and abandon the concept. All US M1 Garand rifles were retrofitted with long-stroke gas pistons. With a long-stroke system, the piston is mechanically fixed to the bolt group and moves through the entire operating cycle; this system is used in weapons such as the Bren light machine gun, AK-47, Tavor, FN Minimi, M249 Squad Automatic Weapon, FN MAG, FN FNC, M1 Garand.
The primary advantage of the long-stroke system is that the mass of the piston rod adds to the momentum of the bolt carrier enabling more positive extraction, ejection and locking. The primary disadvantage to this system is the disruption of the point of aim due to several factors such as: the center of mass changing during the action cycle, abrupt stops at the beginning and end of bolt carrier travel, the use of the barrel as a fulcrum to drive the bolt back. Due to the greater mass of moving parts, more gas is required to operate the system that, in turn, requires larger operating parts. With a short-stroke or tappet system, the piston moves separately from the bolt group, it may directly push the bolt group parts as in the M1 carbine or operate through a connecting rod or assembly as in the Armalite AR-18 or the SKS. In either case, the energy is imparted in a short, abrupt push and the motion of the gas piston is arrested allowing the bolt carrier assembly to continue through the operating cycle through kinetic energy.
This has the advantage of reducing the total mass of recoiling parts compared with a long-stroke piston. This, in turn, enables better control of the weapon due to less mass needing to be stopped at either end of the bolt carrier travel. However, additional complexity, the fact that in many designs the piston is a separate component that impacts the bolt carrier group above the center of gravity, there is a greater potential for premature wear, or damage to the bolt carrier, the rails that guide its rearward movement due to the abrupt uneven impulse. Modern iterations of this design are limited by the physical parameters of the M16 family of weapons as they are a retrofitted solution for addressing the perceived shortcomings of the direct impingement system; the direct impingement method of operation vents gas from partway down the barrel through a tube to the working parts of a rifle where they directly impinge on the bolt carrier. This results in a lighter mechanism. Firearms that use this system include the French MAS-40 from 1940, the Swedish Ag m/42 from 1942, the American M16 rifle family.
One principal advantage is that the moving parts are placed in-line with the bore meaning that sight picture is not disturbed as much. This offers a particular advantage for automatic mechanisms, it has the disadvantage of the propellant gas being blown directly into the action parts. DI operation increases the amount of heat, deposited in the receiver while firing, which can burn off and cover up l
Winchester Repeating Arms Company
The Winchester Repeating Arms Company was a prominent American maker of repeating firearms, located in New Haven, Connecticut. The Winchester brand is owned by the Olin Corporation and the name is used under license by two subsidiaries of the Herstal Group: Fabrique Nationale of Belgium and the Browning Arms Company of Ogden, Utah; the ancestor of the Winchester Repeating Arms Company was the Horace Smith and Daniel Wesson partnership of Norwich, Connecticut. Smith and Wesson acquired Lewis Jennings' improved version of inventor Walter Hunt's 1848 "Volition Repeating Rifle" and its caseless "Rocket Ball" ammunition, produced in small numbers by Robbins & Lawrence of Windsor, Vermont. Jennings' rifle was a commercial failure and Robbins & Lawrence ceased production in 1852. Smith designed a much-improved rifle based on Jennings', the partners hired away Robbins & Lawrence shop foreman Benjamin Tyler Henry. In 1855, the Smith and Wesson partnership, in order to manufacture what they called the "Volcanic" lever-action rifle and pistol, sought investors and incorporated as the Volcanic Repeating Arms Company.
Its largest stockholder was clothing manufacturer Oliver Winchester. The Volcanic rifle had only limited success; the company moved to New Haven in 1856, but by the end of that year became insolvent. Oliver Winchester and his partner John M. Davies purchased the bankrupt firm's assets from the remaining stockholders, reorganized it as the New Haven Arms Company in April 1857. After Smith's departure, Benjamin Henry continued to work with a Smith development project, the self-contained metallic rimfire cartridge, perfected the much larger, more powerful.44 Henry round. Henry supervised a new rifle design based loosely on the Volcanic to use the new ammunition, retaining only the general form of the breech mechanism and the tubular magazine; this became the Henry rifle of 1860, manufactured by the New Haven Arms Company and used in considerable numbers by certain Union army units in the American Civil War. The Henry rifle ensured New Haven Arms' success, together with the Spencer rifle, established the lever-action repeater in the firearms market.
In 1866, Benjamin Henry, angered over what he believed was inadequate compensation, attempted to have the Connecticut legislature award ownership of New Haven Arms to him. Oliver Winchester, hastening back from Europe, forestalled the move and reorganized New Haven Arms yet again as the Winchester Repeating Arms Company. Winchester had the basic design of the Henry rifle modified and improved to become the first Winchester rifle, the Model 1866, which fired the same.44 caliber rimfire cartridges as the Henry but had an improved magazine and, for the first time, a wooden forend. The Henry and the 1866 Winchester shared a unique double firing pin which struck the head of the rimfire cartridge in two places when the weapon was fired, increasing the chances that the fulminate in the hollow rim would ignite the 28 or so grains of black powder inside the case. Another popular model was rolled out in 1873; the Model 1873 introduced the first Winchester center fire cartridge, the.44-40 WCF. These rifle families are known as the "Gun That Won the West."The Model 1873 was followed by the Model 1876, a larger version of the'73, which used the same toggle-link action and brass cartridge elevator used in the Henry.
It was chambered for longer, more powerful cartridges such as.45-60 WCF.45-75 WCF, and.50-95 WCF. The action was not long enough to allow Winchester to achieve their goal of producing a repeating rifle capable of handling the.45-70 Government cartridge. Oliver Winchester died in December 1880. William Wirt Winchester's widow, Sarah Winchester, used her inheritance and income from the company to build what is now known as the Winchester Mystery House. From 1883, John Browning worked in partnership with the Winchester Repeating Arms Company and designed a series of rifles and shotguns, most notably the Winchester Model 1885 Single Shot, Winchester Model 1887 lever-action shotgun, Model 1897 pump-action shotgun. Several of these are still in production today through companies such as Browning, Navy Arms and others which have revived several of the discontinued models or produced reproductions; the early years of the twentieth century found the Winchester Repeating Arms Company competing with new John Browning designs, manufactured under license by other firearm companies.
The race to produce the first commercial self-loading rifle brought forth the.22 rimfire Winchester Model 1903 and centerfire Model 1905, Model 1907, Model 1910 rifles. Winchester engineers, after ten years of work, designed the Model 1911 to circumvent Browning's self-loading shotgun patents, prepared by the company's own patent lawyers. One of Winchester's premier engineers, T. C. Johnson, was instrumental in the development of these self-loading firearms and went on to superintend the designs of Winchester's classic Model 1912, Model 52 and Model 54; the company was a major producer of the.303 Pattern 1914 Enfield rifle for the British Government and the similar.30-06 M1917 Enfield rifle for the United States during World War I. Working at the Winchester plant during the war, Browning developed the final design of the Browning Aut
Oliver Fisher Winchester was an American businessman and politician. He was the son of Samuel Winchester and Hannah Bates and was born in Boston on November 30, 1810, he married Jane Ellen Hope in Boston on February 20, 1834. Their children were: Ann Rebecca Winchester who married Charles B. Dye William Wirt Winchester who married Sarah Lockwood Pardee Hannah Jane Winchester who married Thomas Gray Bennett Winchester was known for manufacturing and marketing the Winchester repeating rifle, a much re-designed descendant of the Volcanic rifle of some years earlier. Winchester started as a clothing manufacturer in Connecticut. During this period he discovered that a division of Smith & Wesson firearms was failing financially with one of their newly patented arms. Having an eye for opportunity, Winchester assembled venture capital together with other stockholders and acquired the S&W division, better known as the Volcanic Repeating Arms Company, in 1855. By 1857, Winchester had positioned himself as the principal stockholder in the company and relocated to New Haven, changing the name to New Haven Arms Company.
The company was plagued by sluggish returns, in part attributed to the design and poor performance of the Volcanic cartridge: a hollow conical ball filled with black powder and sealed by a cork primer. Although the Volcanic's repeater design far outpaced the rival technology, the poor performance and reliability of the.25 and.32 caliber cartridges used in the pistol and rifle models was little match for the competitors' larger calibers. Winchester had inherited a brilliant engineer, Benjamin Tyler Henry, an invaluable asset. Henry sought to improve on the Volcanic repeating rifle by enlarging the frame and magazine to accommodate seventeen of his newly redesigned, all-brass cased.44 caliber rimfire cartridges. This new cartridge put the new company on the map, Henry's ingenuity was rewarded with a patent in his name on October 16, 1860, for what became the famous Henry rifle; the Henry rifle was manufactured for six years with a total production of 12,000 rifles, a number which included both iron and brass frame models.
Following the success of the Henry rifle, the company was reorganized once more and renamed the Winchester Repeating Arms Company. In 1866, employee Nelson King's new improved patent remedied flaws in the Henry rifle by incorporating a loading gate on the side of the frame and integrating a round sealed magazine, covered by a fore stock; the first Winchester rifle was the Model 1866, nicknamed the Yellow Boy. Repeating rifles were used to some extent in the American Civil War. However, the United States Army at that time did not use many repeating rifles as they represented a new, untested technology. Repeating rifles were not used until after the war when they became popular with civilians. Military authorities concentrated on perfecting breech-loading single shot rifles for many more years. With thousands of rifles in the hands of the average pioneer, the Winchester repeating rifles gained a reputation as "the gun that won the West". Oliver Winchester was active in politics, serving as a New Haven City Commissioner, Republican Presidential elector in 1864, as Lieutenant Governor of Connecticut from 1866 - 1867.
When Winchester died on December 11, 1880, his ownership in the company passed to his son, William Wirt Winchester, who died of tuberculosis in March of the next year. William's wife, believed the family was cursed by the spirits killed by the Winchester rifle, moved to San Jose, where she began building a chaotic mansion now known as the Winchester Mystery House with her inheritance, intending to confuse the spirits seeking revenge
A magazine is an ammunition storage and feeding device within or attached to a repeating firearm. Magazines can be integral to the firearm; the magazine functions by moving the cartridges stored within it into a position where they may be loaded into the barrel chamber by the action of the firearm. The detachable magazine is colloquially referred to as a clip, although this is technically inaccurate. Magazines come in many shapes and sizes, from tubular magazines on lever-action rifles that hold only a few rounds, to detachable box and drum magazines for automatic rifles and machine guns that can hold more than one hundred rounds. Various jurisdictions ban what they define as "high-capacity magazines". With the increased use of semi-automatic and automatic firearms, the detachable magazine became common. Soon after the adoption of the M1911 pistol, the term "magazine" was settled on by the military and firearms experts, though the term "clip" is used in its place; the defining difference between clips and magazines is the presence of a feed mechanism in a magazine a spring-loaded follower, which a clip lacks.
A magazine has four parts as follows. A clip may have no moving parts. Examples of clips are moon clips for revolvers. Use of the term "clip" to refer to detachable magazines is a point of strong disagreement; the earliest firearms were loaded with loose powder and a lead ball, to fire more than a single shot without reloading required multiple barrels, such as pepper-box guns and double-barreled shotguns, or multiple chambers, such as in revolvers. Both of these add bulk and weight over a single barrel and a single chamber and many attempts were made to get multiple shots from a single loading of a single barrel through the use of superposed loads. While some early repeaters such as the Kalthoff repeater managed to operate using complex systems with multiple feed sources for ball and primer mass-produced repeating mechanisms did not appear until self-contained cartridges were developed; the first mass-produced repeater was the Volcanic Rifle which used a hollow bullet with the base filled with powder and primer fed into the chamber from a spring-loaded tube called a magazine.
It was named after a room used to store ammunition. The anemic power of the Rocket Ball ammunition used in the Volcanic doomed it to limited popularity.. The Henry repeating rifle is a lever-action, breech-loading, tubular magazine fed rifle, was an improved version of the earlier Volcanic rifle. Designed by Benjamin Tyler Henry in 1860, it was one of the first firearms to use self-contained metallic cartridges; the Henry was introduced in the early 1860s and produced through 1866 in the United States by the New Haven Arms Company. It was adopted in small quantities by the Union in the Civil War and favored for its greater firepower than the standard issue carbine. Many found their way West and was famed both for its use at the Battle of the Little Bighorn, being the basis for the iconic Winchester rifle which are still made to this day; the Henry and Winchester rifles would go on to see service with a number of militaries including Turkey. Switzerland and Italy adopted similar designs; the first magazine-fed firearm to achieve widespread success was the Spencer repeating rifle, which saw service in the American Civil War.
The Spencer used a tubular magazine located in the butt of the gun instead of under the barrel and it used new rimfire metallic cartridges. The Spencer was successful, but the rimfire ammunition did ignite in the magazine tube and destroy the magazine, it could injure the user. The new bolt-action rifles began to gain favor with militaries in the 1880s and were equipped with tubular magazines; the Mauser Model 1871 was a single-shot action that added a tubular magazine in its 1884 update. The Norwegian Jarmann M1884 was adopted in 1884 and used a tubular magazine; the French Lebel Model 1886 rifle used 8-round tubular magazine. The military cartridge was evolving. Cartridges evolved from large-bore cartridges to smaller bores that fired lighter, higher-velocity bullets and incorporated new smokeless propellants; the Lebel Model 1886 rifle was the first rifle and cartridge to be designed for use with smokeless powder and used an 8 mm wadcutter-shaped bullet, drawn from a tubular magazine. This would become a problem when the Lebel's ammunition was updated to use a more aerodynamic pointed bullet.
Modifications had to be made to the centerfire case to prevent the spitzer point from igniting the primer of the next cartridge inline in the magazine through recoil or rough handling. This remains a concern with lever-action firearms today. Two early box magazine patents were the ones by Rollin White in 1855 and William Harding in 1859. A detachable box magazine was patented in 1864 by the American Robert Wilson. Unlike box magazines this magazine fed into a tube magazine and was located in the stock of the gun. Another box magazine, closer to the modern type, was patented in Britain by Mowbray Walker, George Henry Money and Francis Little in 1867. James Paris Lee patented a box magazine which held rounds stacked vertically in 1879 and 1882 and it was first adopted by Austria in the form of an 11mm straight-pull bolt-action rifle, the Mannlicher M1886, it used a cartridge clip which held 5 rounds ready to load into the ma
A firearm is a portable gun that inflicts damage on targets by launching one or more projectiles driven by expanding high-pressure gas produced chemically by exothermic combustion of propellant within an ammunition cartridge. If gas pressurization is achieved through mechanical gas compression rather than through chemical propellant combustion the gun is technically an air gun, not a firearm; the first primitive firearms originated in 10th-century China when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears into the one-person-portable fire lance, used as a shock weapon to good effect in the Siege of De'an in 1132. In the 13th century the Chinese invented the metal-barrelled hand cannon considered the true ancestor of all firearms; the technology spread through the rest of East Asia, South Asia, the Middle East, Europe. Older firearms used black powder as a propellant, but modern firearms use smokeless powder or other propellants. Most modern firearms have rifled barrels to impart spin to the projectile for improved flight stability.
Modern firearms can be described in the case of shotguns by their gauge. Further classification may make reference to the type of barrel used and to the barrel length, to the firing mechanism, to the design's primary intended use, or to the accepted name for a particular variation. Shooters aim firearms at their targets with hand-eye coordination, using either iron sights or optical sights; the accurate range of pistols does not exceed 110 yards, while most rifles are accurate to 550 yards using iron sights, or to longer ranges using optical sights. Purpose-built sniper rifles and anti-materiel rifles are accurate to ranges of more than 2,200 yards. Firearms include a variety of ranged weapons and there is no agreed upon definition. Many soldiers consider a firearm to be any ranged weapon that uses gunpowder or a derivative as a propellant. Small arms include handguns and long guns, such as rifles, submachine guns, personal defense weapons, squad automatic weapons, light machine guns; the world's top small arms manufacturing companies are Browning, Colt, Smith & Wesson, Mossberg, Heckler & Koch, SIG Sauer, Walther, ČZUB, Steyr-Mannlicher, FN Herstal, Norinco, Tula Arms and Kalashnikov, while former top producers were Mauser, Springfield Armory, Rock Island Armory under Armscor.
In 2018, Small Arms Survey reported that there are over one billion small arms distributed globally, of which 857 million are in civilian hands. U. S. civilians alone account for 393 million of the worldwide total of civilian held firearms. This amounts to "120.5 firearms for every 100 residents." The world's armed forces control about 133 million of the global total of small arms, of which over 43 percent belong to two countries: the Russian Federation and China. Law enforcement agencies control about 23 million of the global total of small arms; the smallest of all firearms is the handgun. There are two common types of handguns: semi-automatic pistols. Revolvers have "charge holes" in a revolving cylinder. Semi-automatic pistols have a single fixed firing chamber machined into the rear of the barrel, a magazine so they can be used to fire more than one round; each press of the trigger fires a cartridge, using the energy of the cartridge to activate the mechanism so that the next cartridge may be fired immediately.
This is opposed to "double-action" revolvers which accomplish the same end using a mechanical action linked to the trigger pull. Prior to the 19th century all handguns were single-shot muzzleloaders. With the invention of the revolver in 1818, handguns capable of holding multiple rounds became popular. Certain designs of auto-loading pistol appeared beginning in the 1870s and had supplanted revolvers in military applications by the end of World War I. By the end of the 20th century, most handguns carried by military and civilians were semi-automatic, although revolvers were still used. Speaking and police forces use semi-automatic pistols due to their high magazine capacities and ability to reload by removing the empty magazine and inserting a loaded one. Revolvers are common among handgun hunters because revolver cartridges are more powerful than similar caliber semi-automatic pistol cartridges and the strength and durability of the revolver design is well-suited to outdoor use. Revolvers in.22 LR and 38 Special/357 Magnum, are common concealed weapons in j
Production drawings are complete sets of drawings that detail the manufacturing and assembly of products. Machine operators, production line workers and supervisors all use production drawings. Design engineers use orthographic or pictorial views called "working cases" to record their ideas; these preliminary sketches are used as the basis for assembly drawings. Production drawings are'drawn' information prepared by the design team for use by the construction or production team, the main purpose of, to define the size, shape and production of the building or component'. Orthographic projections are supplied, giving views of machine parts and their assembly in an accessible form akin to artistic rendering in perspective, sometimes in exploded form which illustrates how the whole may be constructed from sub-assemblies and sub-assemblies into individual components; the production drawings may describe the preferred order in which to assemble components and if the engineering drawings call for a screw fastener to be tightened to a specific torque the production drawings would describe the tool to be used and how it should be calibrated.
Material and component specifics are provided in the title block of a production drawing. Sub-assemblies are shown and the production drawings may specify where each assembled component will be built. Production drawings record the number of parts that are required for making the assembled unit and may form an essential part of the documentation required to authorise the production of the item described. Three main sets of production drawings include the following: Detail of each non-standard part on a drawing sheet one part per sheet Assembly drawing showing all parts on one sheet A Bill of materials of each part The basic elements of production drawings include: Size and shape of component Format of drawing sheet Process sheet Projection method Limits and tolerances of size and position Production method Indication of surface roughness and other heat treatments Material specification and Shape such as Castings, Plates, etc. Conventions used to represent certain machine components Inspection and Testing Methods Specification of Standard Components The basic principles of dimensioning in production drawings include the following: The drawing module should dimension each feature only once.
The drawing should show no more dimensions than necessary. Place dimensions outside the drawing view as far as possible. Represent dimensions by visible outlines rather than by hidden lines. Avoid dimensioning the center line, except when it passes through the center hole. Avoid intersecting projection or dimension lines. If the space for dimensioning is insufficient, you may reverse arrow heads and replace adjacent arrow heads with dots. Any engineering drawing requires specifications in terms of dimensions. Dimensions are classified as the following: Functional dimensions Non-functional dimensions Auxiliary dimensionsNon-functional dimensions are required for manufacturing. Auxiliary dimensions do not govern inspection of parts, they are arranged in the following ways: Chain dimensioning: This method can be used only where the accumulation of tolerances does not affect the functional requirements. Parallel dimensioning: In this type of dimensioning, a number of single dimension lines are drawn parallel to one another, spaced so as to accommodate the dimensional values.
Running dimensioning: This type of dimensioning is similar to parallel dimensioning. In this case, the origin point should be marked. Coordinate dimensioning: The location of each hole and its size is given by specifying X and Y coordinates from the defined origin and tabulating them. There are three terms used in the limit system: Tolerance: Deviation from a basic value is defined as Tolerance, it can be obtained by taking the difference between minimum permissible limits. Limits: Two extreme permissible sizes between which the actual size is contained are defined as limits. Deviation: The algebraic difference between a size and its corresponding basic size. There are two types of deviations: 1) Upper deviation 2) Lower deviationThe fundamental deviation is either the upper or lower deviation, depending on, closer to the basic size. Due to human errors, machine settings, etc. it is nearly impossible to manufacture an absolute dimension as specified by the designer. Deviation in dimensions from the basic value always arises.
This deviation of dimensions from the basic value is known as Tolerance. The figure shows mechanical tolerances; the relation between tightness and looseness between two mating parts is called fit. Depending upon the actual limits of the hole or shaft sizes, fits may be classified as clearance fit, transition fit and interference fit. Clearance fit is defined as a clearance between mating parts. In clearance fit, there is always a positive clearance between the shaft. Transition fit may result in either an interference or clearance, depending upon the actual values of the tolerance of individual parts. Interference fit is obtained if the difference between the hole and shaft sizes is negative before assembly. Interference fit ranges from minimum to maximum interference; the two extreme cases of interference are as follows: The magnitude of the difference between the maximum size of the hole and the minimum size of the shaft in an interference fit befo