desk |
screwdriver |
top 10 words in brain distribution (in article): build wood store design wall structure type home size provide |
top 10 words in brain distribution (in article): design type time blade century size steel common head allow |
top 10 words in brain distribution (not in article): city material house street town floor state paint Unite construction |
top 10 words in brain distribution (not in article): light drink lamp wine beer water produce bottle iron valve |
times more probable under desk 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under screwdriver (words not in the model) | |
A desk'" is a furniture form and a class of table often used in a work or office setting for reading or writing on or using a computer. Desks often have one or more drawers to store office supplies and papers. Unlike a regular table, usually only one side of a desk is suitable to sit on (though there are some unusual exceptions, such as a partners desk). Not all desks have the form of a table. For instance, an Armoire desk is a desk built within a large wardrobe-like cabinet, and a portable desk is light enough to be placed on a person's lap. Early desks. Desk-style furniture appears not to have been used in classical antiquity or in other ancient centers of civilization in the Middle East or Far East, but there is no specific proof. Medieval illustrations show the first pieces of furniture which seem to have been designed and constructed for reading and writing. Before the invention of the movable type printing press in the 15th century, any reader was potentially a writer or publisher or both, since any book or other document had to be copied by hand. The desks were designed with slots and hooks for bookmarks and for writing implements. Since manuscript volumes were sometimes large, and heavy, desks of the period usually had massive structures. Desks of the Renaissance and later eras had relatively slimmer structures, and more and more drawers as woodworking became more precise and cabinet-making became a distinct trade. It is often possible to find out if a table or other piece of furniture of those times was designed to be used as a desk by looking for a drawer with three small separations (one each for the ink pot, the blotter and the powder tray) and room for the pens. The desk forms we are familiar with in this beginning of the millennium were born mostly in the 17th and 18th centuries. The ergonomic desk of the last decades is the newest addition to a long list of desk forms, but in a way it is only a refinement of the mechanically complex drawing table or drafting table of the end of the 18th century. Industrial era. Refinements to those first desk forms were considerable through the 19th century, as steam-driven machinery made cheap wood-based paper possible in the last periods of the first phase of the industrial revolution. This produced a boom in the number of, or some might say the birth of, the white-collar worker. As these office workers grew in number, desks were mass-produced for them in large quantities, using newer, steam-driven woodworking machinery. This was the first sharp division in desk manufacturing. From then on, limited quantities of finely crafted desks have been constructed by master cabinetmakers for the homes and offices of the rich while the vast majority of desks were assembled rapidly by unskilled labor, from components turned out in batches by machine tools. Thus, age alone does not guarantee that an antique desk is a masterpiece, since this shift took place more than a hundred years ago. More paper and more correspondence drove the need for more complex desks and more specialized desks, such as the rolltop desk which was a mass produced, slatted variant of the classical cylinder desk. It provided a relatively fast and cheap way to lock up the ever increasing flow of paper without having to file everything by the end of the day. Paper documents started leaving the desk as a "home," with the general introduction of filing cabinets. Correspondence and other documents were now too numerous to get enough attention to be rolled up or folded again, then summarized and tagged before being pigeonholed in a small compartment over or under the work surface of the desk. The famous Wooton desk and others were the last manifestations of the "pigeonhole" style. The newer desks could be transformed into many different shapes and angles and were ideal for artists. Steel desks. A smaller boom in office work and desk production occurred at the end of the 19th century and the beginning of the 20th with the introduction of smaller and cheaper electrical presses and efficient carbon papers coupled with the general acceptance of the typewriter. Steel desks were introduced to take heavier loads of paper and withstand the pounding meted out on the typewriters. The L-shaped desk became popular, with the "leg" being used as an annex for the typewriter. Another big boom occurred after the Second World War with the spread of photocopying. Paperwork drove even higher the number of desk workers, whose work surface diminished in size as office rents rose, and the paper itself was moved more and more directly to filing cabinets or sent to records management centers, or transformed into microfilm, or both. Modular desks seating several co-workers close by became common. Even executive or management desks became mass-produced, built of cheap plywood or fiberboard covered with wood veneer, as the number of persons managing the white collar workers became even greater. Student desks. A "'student desk'" can be any desk form meant for use by a student. Usually the term designates a small pedestal desk or writing table constructed for use by a teenager or a pre-teen in his or her room at home. More often than not it is a pedestal desk, with only one of the two pedestals and about two thirds of the desk surface. Such desks are sometimes called left pedestal desks or right pedestal desks depending on the position of the single pedestal. The height of the desk is usually a bit lower than is the case for normal adult desks. In some cases, the desk is connected from the seat to the table. The table is also used for sitting before classes. The desks are usually mass-produced in steel or wood and sold on the consumer market. In addition there is a wide variety of plans available for woodworking enthusiasts. There are many novel forms of student desks made to maximize the relatively restricted area available in a child's room. One of the most common is the bunk bed desk, also known as a loft bed. Impact of computers. Until the late 1980s desks remained a place for paperwork and business negotiation. At the end of this decade though the personal computer was taking | The screwdriver'" is a device specifically designed to insert and tighten, or to loosen and remove, screws. The screwdriver is made up of a head or tip, which engages with a screw, a mechanism to apply torque by rotating the tip, and some way to position and support the screwdriver. A typical hand screwdriver comprises an approximately cylindrical handle of a size and shape to be held by a human hand, and an axial shaft fixed to the handle, the tip of which is shaped to fit a particular type of screw. The handle and shaft allow the screwdriver to be positioned and supported and, when rotated, to apply torque. Screwdrivers are made in a variety of shapes, and the tip can be rotated manually or by an electric or other motor. A screw has a head with a contour such that an appropriate screwdriver tip can be engaged in it in such a way that the application of sufficient torque to the screwdriver will cause the screw to rotate. History. Gunsmiths still refer to a screwdriver as a "turnscrew", under which name it is an important part of a set of pistols. The name was common in earlier centuries, used by cabinet makers and shipwrights and perhaps other trades. The Cabinet-Maker's screwdriver is one of the longest-established handle forms, somewhat oval or elipsoid in cross section. This is variously attributed to improving grip or preventing the tool rolling off the bench, but there is no reason to suppose these are not rationalisations. The shape has been popular for a couple of hundred years. It is usually associated with a plain head for slotted screws, but has been used with many head forms. "See Also: "The History of Screws Types and variations. There are many types of screw heads, of which the most common are the slotted, Phillips, PoziDriv SupaDriv (crosspoint), Robertson, TORX, and Allen (hex). Screwdrivers come in a large variety of sizes to match those of screws, from tiny jeweler's screwdrivers up. If a screwdriver that is not the right size and type for the screw is used, it is likely that the screw will be damaged in the process of tightening it. This is less important for PoziDriv and SupaDriv, which are designed specifically to be more tolerant of size mismatch. When tightening a screw with force, it is important to press the head hard into the screw, again to avoid damaging the screw. Some manual screwdrivers have a ratchet action whereby the screwdriver blade is locked to the handle for clockwise rotation, but uncoupled for counterclockwise rotation when set for tightening screws; and vice versa for loosening. Many screwdriver designs have a handle with detachable head (the part of the screwdriver which engages with the screw), called "bits" as with drill bits, allowing a set of one handle and several heads to be used for a variety of screw sizes and types. This kind of design has allowed the development of electrically powered screwdrivers, which, as the name suggests, use an electric motor to rotate the bit. In such cases the terminology for power drills is used, e.g. "shank" or "collet". Some drills can also be fitted with screwdriver heads. Manual screw drivers with a spiral ratchet'" mechanism to turn pressure (linear motion) into rotational motion also exist, and predate electric screwdrivers. The user pushes the handle toward the workpiece, causing a pawl in a spiral groove to rotate the shank and the removable bit. The ratchet can be set to rotate left or right with each push, or can be locked so that the tool can be used like a conventional screwdriver. Once very popular, these spiral ratchet drivers, using proprietary bits, have been largely discontinued by manufacturers such as Stanley, although one can still find them at vintage tool auctions. Companies such as Lara Specialty Tools now offer a modernized version that uses standard 1 /4-inch hex shank power tool bits. Since a variety of drill bits are available in this format, it allows the tool to do double duty as a "push drill". Many modern electrical appliances, if they contain screws at all, use screws with heads other than the typical slotted or Phillips styles. TORX is one such pattern that has become very widespread. The main cause of this trend is manufacturing efficiency: TORX and other types are designed so the driver will not slip out of the fastener as will a Phillips driver. (Slotted screws are rarely used in mass-produced devices, since the driver is not inherently centered on the fastener). A benefit disadvantage of non-typical fasteners (depending on your point of view) is that it can be more difficult for users of a device to disassemble it than if more-common head types were used, but TORX and other drivers are widely available. Specialized patterns of security screws are also used, such as the Gamebit head style used in all Nintendo consoles, though drivers for most security heads are, again, readily available. While screwdrivers are designed for the above functions, they are commonly also used as improvised substitutes for pry bars, levers, and hole punches, as well as other tools. There is no such thing as a "left-handed screwdriver", as the device can easily be wielded in either hand. To be sent on an errand to find a left-handed screwdriver is often a test of stupidity, or is used as a metaphor for something useless. The term "Birmingham screwdriver" is used jokingly in the UK to denote a hammer or sledgehammer. The handle and shaft of screwdrivers have changed considerably over time. The design is influenced by both purpose and manufacturing requirements. The "Perfect Handle" screwdriver was first manufactured by HD Smith & Company that operated from 1850 to 1900. Many manufacturers adopted this handle design world wide. The "Flat Bladed" screwdriver was another design composed of drop forged steel with riveted wood handles? Among slotted screwdrivers, there are a couple of major variations at the blade or bit end involving the profile of the blade as viewed face-on. The more common type is sometimes referred to as keystone'", where the blade profile is slightly flared before tapering off at the end. To maximize access in space-restricted applications, the same edges for the "'cabinet'" variety, in contrast, are straight and parallel, meeting the end of the blade at a right angle. |