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47-474: The English clockmaker William Clement is credited with developing the form in 1670. Pendulum clocks were the world's most accurate timekeeping technology until the early 20th century, and longcase clocks, due to their superior accuracy, served as time standards for households and businesses. Today, they are kept mainly for their decorative and antique value, having been superseded by analog and digital timekeepers. The Oxford English Dictionary states that

94-404: A block and tackle . A block and tackle is assembled so one block is attached to the fixed mounting point and the other is attached to the moving load. The ideal mechanical advantage of the block and tackle is equal to the number of sections of the rope that support the moving block. In the diagram on the right, the ideal mechanical advantage of each of the block and tackle assemblies shown

141-489: A "Royal" pendulum) meaning that each swing (or half-period) takes one second. They are about 1 metre (3 ft 3 in) long (to the centre of the bob), requiring a long, narrow case. That case pre-dated the anchor clock by a few decades, appearing in clocks in 1660, to allow a long drop for the powering weights. However, once the seconds pendulum began to be used, the long case proved perfect for housing it as well. British clockmaker William Clement, who disputed credit for

188-419: A case, so most free-standing clocks had short pendulums. The anchor mechanism reduced the pendulum's swing to around 4 to 6 degrees, allowing clockmakers to use longer pendulums, which had slower "beats". They consumed less power, allowing clocks to run longer between windings, caused less friction and wear in the movement, and were more accurate. Almost all longcase clocks use a seconds pendulum (also called

235-620: A confederation of art and antique associations across 21 countries that represents 5,000 dealers. The common definition of antique is a collectible object such as a piece of furniture or work of art that has an enhanced value because of its considerable age, but it varies depending on the item, its source, the year of its creation, etc. The customary definition of antique requires that an item should be at least 100 years old and in original condition. (Motor vehicles are an exception to this rule, with some definitions requiring an automobile to be as little as 25 years old to qualify as an antique. ) In

282-402: A more accurate variation of the anchor escapement called the deadbeat escapement . Traditionally, longcase clocks were made with two types of movement : eight-day and one-day (30-hour) movements. A clock with an eight-day movement required winding only once a week, while generally less-expensive 30-hour clocks had to be wound daily. Eight-day clocks are often driven by two weights – one driving

329-814: A piece of red sealing wax that bears the government chop to verify the date of the antique. The government of the People's Republic of China has its own definitions of what it considers antique . As of the Cultural Revolution and China's opening trade to other countries, the government has tried to protect the definition of a Chinese antique. Antiquing is the act of shopping, identifying, negotiating, or bargaining for antiques. People buy items for personal use, gifts, or profit. Sources for antiquing include garage sales and yard sales, estate sales , resort towns, antique districts, collectives , and international auction houses. Note that antiquing also means

376-409: A pulley system can be analysed using free body diagrams which balance the tension force in the rope with the force of gravity on the load. In an ideal system, the massless and frictionless pulleys do not dissipate energy and allow for a change of direction of a rope that does not stretch or wear. In this case, a force balance on a free body that includes the load, W , and n supporting sections of

423-433: A rope with tension T , yields: The ratio of the load to the input tension force is the mechanical advantage MA of the pulley system, Thus, the mechanical advantage of the system is equal to the number of sections of rope supporting the load. A belt and pulley system is characterized by two or more pulleys in common to a belt . This allows for mechanical power , torque , and speed to be transmitted across axles. If

470-411: A scene where Archimedes proved the effectiveness of compound pulleys and the block-and-tackle system by using one to pull a fully laden ship towards him as if it was gliding through water. A block is a set of pulleys (wheels) assembled so that each pulley rotates independently from every other pulley. Two blocks with a rope attached to one of the blocks and threaded through the two sets of pulleys form

517-401: A shaft. A sheave or pulley wheel is a pulley using an axle supported by a frame or shell ( block ) to guide a cable or exert force. A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope , cable , belt, or chain . The earliest evidence of pulleys dates back to Ancient Egypt in

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564-640: A special variety of longcase clocks was made in Mora , called Mora clocks . Bornholm clock-making began in the 1740s when an English ship, which had longcase clocks in its hold , was stranded. They were sent for repair to a turner named Poul Ottesen Arboe in Rønne and as a result of his repair of them he learned enough about clocks to begin to make his own. British Irish Finnish Americans Australian casemaker Antique An antique (from Latin antiquus  'old, ancient')

611-527: A style of longcase clock made in the French region Franche-Comté (hence their name). Features distinguishing this style are a curving "potbellied" case and a greater use of curved lines. A heavy, elongated, highly ornamented pendulum bob often extends up the case (see photo). Production of these clocks began in 1680 and continued for about 230 years. During the peak production years (1850–1890) over 60,000 clocks were made each year. These clocks were trendy across

658-537: Is a popular area of antiques because furniture has obvious practical uses as well as collector value. Many collectors use antique furniture pieces in their homes, and care for them with the hope that the value of these items will remain same or appreciate. This is in contrast to buying new furniture, which typically depreciates from the moment of purchase. Antique furniture includes dining tables, chairs, bureaus, chests etc. The most common woods are mahogany , oak, pine , walnut , and rosewood . Chinese antique furniture

705-414: Is an item perceived as having value because of its aesthetic or historical significance, and often defined as at least 100 years old (or some other limit), although the term is often used loosely to describe any object that is old. An antique is usually an item that is collected or desirable because of its age, beauty, rarity, condition, utility, personal emotional connection, and/or other unique features. It

752-582: Is an object that represents a previous era or time period in human history. Vintage and collectible are used to describe items that are old, but do not meet the 100-year criterion. Antiques are usually objects of the decorative arts that show some degree of craftsmanship, collectability, or an attention to design, such as a desk or an early automobile. They are bought at antiques shops , estate sales, auction houses, online auctions, and other venues, or estate inherited. Antiques dealers often belong to national trade associations , many of which belong to CINOA ,

799-422: Is antique which was made after 1830, although the barrier has been broken down in recent years by the enthusiasm of collectors for Art Nouveau and Art Deco . The alternative term, antiquities , commonly refers to the remains of ancient art and everyday items from antiquity , which themselves are often archaeological artifacts . An antiquarian is a person who collects and studies antiquities or things of

846-449: Is as follows: A rope and pulley system—that is, a block and tackle —is characterised by the use of a single continuous rope to transmit a tension force around one or more pulleys to lift or move a load—the rope may be a light line or a strong cable. This system is included in the list of simple machines identified by Renaissance scientists. If the rope and pulley system does not dissipate or store energy, then its mechanical advantage

893-588: Is fully operational, with chimes on each quarter hour. It was made by Svoboda Industries in 1976 as a Bicentennial project and is located in Kewaunee, Wisconsin . The advent of the longcase clock was due to the invention of the anchor escapement mechanism by Robert Hooke in about 1658. Before adopting the anchor mechanism, pendulum clock movements used an older verge escapement mechanism, which required very wide pendulum swings of about 80–100 degrees. Long pendulums with such wide swings could not be fitted within

940-429: Is its hardware fittings, the style of which varies from one period to another. For example, Victorian era hardware is different from other period hardware and is perceived to be aesthetically defined; this is the reason for its popularity. Pulley A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and

987-501: Is often made with elm, a wood common to many regions in Asia. Each wood has a distinctive grain and color. Many modern pieces of furniture use laminate or wood veneer to achieve the same effect. There are a number of different styles of antique furniture depending on when and where it was made. Some examples of stylistic periods are: Arts & Crafts , Georgian , Regency , and Victorian . An important part of some antique furniture

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1034-405: Is the number of parts of the rope that act on the load. This can be shown as follows. Consider the set of pulleys that form the moving block and the parts of the rope that support this block. If there are p of these parts of the rope supporting the load W, then a force balance on the moving block shows that the tension in each of the parts of the rope must be W/p. This means the input force on

1081-467: Is the term used to describe the application of a coating, cover or wearing surface with various textured patterns which is sometimes applied to pulley shells. Lagging is often applied in order to extend the life of the shell by providing a replaceable wearing surface or to improve the friction between the belt and the pulley. Notably drive pulleys are often rubber lagged (coated with a rubber friction layer) for exactly this reason. Applying powdered rosin to

1128-569: The Twelfth Dynasty (1991–1802 BC) and Mesopotamia in the early 2nd millennium BC. In Roman Egypt , Hero of Alexandria (c. 10–70 AD) identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another. Plutarch 's Parallel Lives recounts

1175-495: The block and tackle is said to be "rove to advantage." Diagram 3 shows that now three rope parts support the load W which means the tension in the rope is W/3 . Thus, the mechanical advantage is three. By adding a pulley to the fixed block of a gun tackle the direction of the pulling force is reversed though the mechanical advantage remains the same, Diagram 3a. This is an example of the Luff tackle. The mechanical advantage of

1222-572: The United States, the Smoot-Hawley Tariff Act (para.1811) exempted "...works of art (except rugs and carpets made after the year 1700), collections in illustration of the progress of the arts, works in bronze , marble , terra cotta , parian , pottery, or porcelain , artistic antiquities and objects of ornamental character or educational value which shall have been produced prior to the year 1830" (emphasis added) . 1830

1269-418: The anchor escapement with Robert Hooke, had made the first longcase clocks by 1680. Later the same year, Thomas Tompion , the most prominent British clockmaker, was making them too. Longcase clocks spread rapidly from England to other European countries and Asia. The first longcase clocks, like all clocks prior to the anchor escapement, had only one hand; an hour hand . The increased accuracy made possible by

1316-530: The anchor motivated the addition of the minute hand to clock faces in the next few decades. Between 1680 and 1800, the average price of a grandfather clock in England remained steady at £1 10s. In 1680, that was the amount paid by an average working family for a year's rent, so the purchase of clocks was confined to the wealthy. But by 1800, wages had increased enough to allow many lower middle-class households to own grandfather clocks. Modern longcase clocks use

1363-405: The chain hanging down next to the weight. To wind a chain-driven longcase clock, one pulls on the end of each chain , lifting the weights until they are just under the clock's face. In the early 20th century, quarter-hour chime sequences were added to longcase clocks. A full chime sequence sounds at the top of each hour, immediately followed by the hour strike. At 15 minutes after each hour, 1/4 of

1410-423: The chime sequence plays. Proceeding that, at the bottom of each hour, 1/2 of the chime sequence plays. Then finally, at 15 minutes before each hour, 3/4 of the chime sequence plays. The chime tune used in almost all longcase clocks is Westminster Quarters . Many also offer the option of Whittington chimes or St. Michael's chimes , selectable by a switch mounted on the right side of the dial, allowing one to silence

1457-437: The chimes if desired. As a result of adding chime sequences, all modern mechanical longcase clocks have three weights instead of only two. The left weight provides power for the hour strike, the middle-weight provides power for the clock's pendulum and general timekeeping functions, and the right weight provides power for the quarter-hour chime sequences. Comtoise clocks , also known as Morbier clocks or Morez clocks , are

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1504-432: The clock became inaccurate, and when the second owner died, the clock stopped working altogether. The story inspired Henry to create the song. Grandfather clocks are of a certain height, usually at least 1.9 metres (6 ft 3 in). There are also so-called "grandmother" and "granddaughter" clocks, which are slightly shorter. The world's tallest grandfather clock is 35 feet 10 inches (10.92 m) tall and

1551-412: The craft of making an object appear antique through distressing or using the antique-looking paint applications. Often, individuals get confused between these handmade distressed vintage or modern items and true antiques. Would-be antique collectors who are unaware of the differences may find themselves paying a high amount of money for something that would have little value if re-sold. Antique furniture

1598-436: The diameters of pulleys determine those same factors. Cone pulleys and step pulleys (which operate on the same principle, although the names tend to be applied to flat belt versions and V-belt versions, respectively) are a way to provide multiple drive ratios in a belt-and-pulley system that can be shifted as needed, just as a transmission provides this function with a gear train that can be shifted. V-belt step pulleys are

1645-445: The early 1950s generally had a belt pulley for a flat belt (which is what Belt Pulley magazine was named after). It has been replaced by other mechanisms with more flexibility in methods of use, such as power take-off and hydraulics . Just as the diameters of gears (and, correspondingly, their number of teeth) determine a gear ratio and thus the speed increases or reductions and the mechanical advantage that they can deliver,

1692-751: The generations; they kept the time on farms throughout France. Many Comtoise clocks can be found in France but they are also frequently found in Spain, Germany, and other parts of Europe , less in the United States. Many Comtoise clocks were also exported to other countries in Europe and even farther, to the Ottoman Empire and as far as Thailand. A wooden sheath usually protected the metal mechanisms during transport. Bornholm clocks are Danish longcase clocks and were made on Bornholm from 1745 to 1900. In Sweden

1739-442: The most common way that drill presses deliver a range of spindle speeds. With belts and pulleys, friction is one of the most important forces. Some uses for belts and pulleys involve peculiar angles (leading to bad belt tracking and possibly slipping the belt off the pulley) or low belt-tension environments, causing unnecessary slippage of the belt and hence extra wear to the belt. To solve this, pulleys are sometimes lagged. Lagging

1786-411: The past. Traditionally, Chinese antiques are marked by a red seal , known as a 'chop', placed there by an owner. Experts can identify previous owners of an antique by reading the chops. The pre-revolution Chinese government tried to assist collectors of Chinese antiques by requiring their Department of Antiquities to provide a governmental chop on the bottom of a Chinese antique. This chop is visible as

1833-406: The pendulum and the other the striking mechanism , which usually consisted of a bell or chimes. Such movements usually have two keyholes, one on each side of the dial, to wind each weight. By contrast, 30-hour clocks often had a single weight to drive the timekeeping and striking mechanisms. Some 30-hour clocks were made with false keyholes for customers who wanted guests to think that the household

1880-593: The popular 1876 song My Grandfather's Clock is responsible for the common name "grandfather clock" being applied to the longcase clock. The song was composed by the American songwriter Henry Clay Work , who discovered a longcase clock in The George Hotel in Piercebridge , County Durham , England. When he asked about the clock, he was informed that it had had two owners. After the first owner died,

1927-410: The pulleys are of differing diameters, a mechanical advantage is realized. A belt drive is analogous to that of a chain drive ; however, a belt sheave may be smooth (devoid of discrete interlocking members as would be found on a chain sprocket, spur gear , or timing belt) so that the mechanical advantage is approximately given by the ratio of the pitch diameter of the sheaves only, not fixed exactly by

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1974-446: The ratio of teeth as with gears and sprockets. In the case of a drum-style pulley, without a groove or flanges, the pulley often is slightly convex to keep the flat belt centered. It is sometimes referred to as a crowned pulley. Though once widely used on factory line shafts , this type of pulley is still found driving the rotating brush in upright vacuum cleaners , in belt sanders and bandsaws . Agricultural tractors built up to

2021-408: The rope is T = W/p. Thus, the block and tackle reduces the input force by the factor p. The simplest theory of operation for a pulley system assumes that the pulleys and lines are weightless and that there is no energy loss due to friction. It is also assumed that the lines do not stretch. In equilibrium, the forces on the moving block must sum to zero. In addition the tension in the rope must be

2068-405: The same for each of its parts. This means that the two parts of the rope supporting the moving block must each support half the load. These are different types of pulley systems: The mechanical advantage of the gun tackle can be increased by interchanging the fixed and moving blocks so the rope is attached to the moving block and the rope is pulled in the direction of the lifted load. In this case

2115-405: The top of each weight. The mechanical advantage of that arrangement also doubles the running time allowed by a given weight drop. Cable clocks are wound by inserting a special crank (called a "key") into holes in the clock's face and turning it. Others, however, are chain-driven, meaning that the weights are suspended by chains that wrap around gears in the clock's mechanism, with the other end of

2162-405: Was able to afford the more expensive eight-day clock. All modern striking longcase clocks have eight-day mechanical quarter chiming and full hour striking movements. Most longcase clocks are cable-driven, meaning that cables suspend the weights. If the cable was attached directly to the weight, the load would cause rotation and untwist the cable strands, so the cable wraps around a pulley mounted to

2209-459: Was the approximate beginning of mass production in the United States; at the time, 1930, it also marked an age of at least 100 years. These definitions were intended to allow people of that time to distinguish between genuine antique pieces, vintage items, and collectible objects. In 1979, the British art critic Edward Lucie-Smith wrote that "Antique-dealers ... sometimes insist that nothing

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