|
Hinge
A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation: all other translations or rotations being prevented, and thus a hinge has one degree of freedom. Hinges may be made of flexible material or of moving components. In biology, many joints function as hinges, like the elbow joint. History Ancient remains of stone, marble, wood, and bronze hinges have been found. Some date back to at least Ancient Egypt. In Ancient Rome, hinges were called cardō and gave name to the goddess Cardea and the main street Cardo. This name cardō lives on figuratively today as "the chief thing (on which something turns or depends)" in words such as ''cardinal''. According to the OED, the English word hinge is related to '' hang''. Door hinges ; Barrel hinge: A barrel hinge consists of a sectional barrel (the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concealed Hinge Jig
A concealed hinge drilling jig is a type of support jig, designed for drilling 3 cm holes to fit concealed hinges into modern wardrobe doors. As many of the complementary tools used in woodworking, it uses an electric hand-drill for its operation, making a Forstner bit to turn. For most ''concealed hinge''s to work properly, a pit hole must be created on the door at the point where it faces the static part of the hinge which is screwed to the inside wall of the wardrobe. To create the pit hole, the jig must be fixed in place by means of the provided clamp, spin the Forstner bit by applying an electric hand-drill to its axle. The hole is drilled by pressing the hand-drill until a satisfactory pit hole is created. The purpose of the drilling jig is to hold a Forstner bit in place, at a 90º angle while drilling 3 cm pit hole. The angle of the tool is critical for the performance of concealed hinges, the jig allows maintaining the 90º angle over a number of drilling sessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Door Closer
A door closer is defined as any mechanical device that closes a door in a controlled manner, preventing it from slamming, in general after someone opens it, or after it was automatically opened. The force used to open the door is stored in some type of spring and when released this energy is then used to return the door to a closed position. Door closers can be linked to a building's fire alarm system. Where doors need to be held open for the majority of the time they are held back with an electromagnetic device. When the fire alarm is triggered it cuts power to the electromagnetic hold-open device allowing the doors to close. These hold-open devices can be separate from the door closer or part of its design. Early history Gravity alone may be considered to be the first "door closer". Before any mechanical devices were attached to doors to close them, the way in which the door was hung automatically closed the door once opened. This technique to hang doors may have originated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardea
Cardea or Carda was the ancient Roman goddess of the hinge (Latin ''cardo, cardinis''), Roman doors being hung on pivot hinges. The Augustan poet Ovid conflates her with another archaic goddess named Carna, whose festival was celebrated on the Kalends of June and for whom he gives the alternative name Cranê or Cranea, a nymph. Ovid's conflation of the goddesses is likely to have been his poetic invention, but it has also been conjectured that ''Carna'' was a contracted form of ''Cardina'', and at minimum Ovid was observing that their traditions were congruent. Cardea and doorways In the Christian polemic of the Church Fathers, Cardea is associated with two otherwise unknown deities who preside over doorways: Forculus, from ''fores'', "door", plural in form because double doors were common on public buildings and elite homes ('' domūs''); and Limentinus, from ''limen, liminis'', "threshold" (compare English " liminal"). St. Augustine mocks the apparent triviality of these "li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flexure Bearing
A flexure bearing is a category of flexure which is engineered to be compliant in one or more angular degrees of freedom. Flexure bearings are often part of compliant mechanisms. Flexure bearings serve much of the same function as conventional bearings or hinges in applications which require angular compliance. However, flexures require no lubrication and exhibit very low or no friction. Many flexure bearings are made of a single part: two rigid structures joined by a thin "hinge" area. A hinged door can be created by implementing a flexible element between a door and the door frame, such that the flexible element bends allowing the door to pivot open. Flexure bearings have the advantage over most other bearings that they are simple and thus inexpensive. They are also often compact, lightweight, have very low friction, and are easier to repair without specialized equipment. Flexure bearings have the disadvantages that the range of motion is limited, and often very limited for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mortise And Tenon
A mortise and tenon (occasionally mortice and tenon) joint connects two pieces of wood or other material. Woodworkers around the world have used it for thousands of years to join pieces of wood, mainly when the adjoining pieces connect at right angles. Mortise and tenon joints are strong and stable joints that can be used in many projects. They furnish a strong outcome and connect by either gluing or locking into place. The mortise and tenon joint also gives an attractive look. One drawback to this joint is the difficulty in making it because of the precise measuring and tight cutting required. In its most basic form, a mortise and tenon joint is both simple and strong. There are many variations of this type of joint, and the basic mortise and tenon has two components: #the mortise hole, and #the tenon tongue. The tenon, formed on the end of a member generally referred to as a rail, fits into a square or rectangular hole cut into the other, corresponding member. The tenon is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Draw Bridge
A drawbridge or draw-bridge is a type of moveable bridge typically at the entrance to a castle or tower surrounded by a moat. In some forms of English, including American English, the word ''drawbridge'' commonly refers to all types of moveable bridges, such as bascule bridges, vertical-lift bridges and swing bridges, but this article concerns the narrower historical definition of the term where the bridge is used in a defensive structure. As used in castles or defensive structures, drawbridges provide access across defensive structures when lowered, but can quickly be raised from within to deny entry to an enemy force. Castle drawbridges Medieval castles were usually defended by a ditch or moat, crossed by a wooden bridge. In early castles the bridge might be designed to be destroyed or removed in the event of an attack, but drawbridges became very common. A typical arrangement would have the drawbridge immediately outside a gatehouse, consisting of a wooden deck with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments. Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations.Based on definition from: Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardo
A cardo (plural ''cardines'') was a north–south street in Ancient Roman cities and military camps as an integral component of city planning. The cardo maximus, or most often the ''cardo'', was the main or central north–south-oriented street. Etymology The ''cardo maximus'' was the "hinge" or axis of the city, derived from Greek καρδίᾱ, kardia ("heart") and as such was generally lined with shops and vendors, and served as a hub of economic life. Most Roman cities also had a Decumanus Maximus, an east–west street that served as a secondary main street. Due to varying geography, in some cities the Decumanus is the main street and the Cardo is secondary, but in general the Cardo maximus served as the primary street. The Forum was normally located at, or close to, the intersection of the Decumanus and the Cardo. Examples Apamea, Syria The Cardo Maximus of Apamea, Syria ran through the centre of the city directly from North to South, linked the principal gates of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dakin Building
The Dakin Building is an architectural award-winning class A office building on the San Francisco Bay in Brisbane, California. Serving as a corporate headquarters building for several companies of national prominence, it was built from the profits of the Garfield character whose licensed products of the R. Dakin Company division of Applause Toys soared in sales in the late 1980s. Located on Sierra Point, it became a landmark in the San Francisco Bay Area for its distinctive design and was nicknamed the Luke Skywalker building for its dramatic posture overlooking the bay, in contrast to a neighboring office building with a dark, ominous appearance that was nicknamed the Darth Vader building. Ownership and history The Dakin Building was constructed in 1986 under commission of the R. Dakin Company, one of the largest manufacturers of plush products (mainly teddy bears) in the United States at that time. Dakin was in a large upswing of sales and profits in the late 1980s fue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deployable Structure
A deployable structure is a structure that can change shape so as to significantly change its size. Examples of deployable structures are umbrellas, some tensegrity structures, bistable structures, some Origami shapes and scissor-like structures. Deployable structures are also used on spacecraft for deploying solar panels and solar sails. Space-based deployable structures can be categorized into three primary classes: the first is the articulated structure class wherein rigid members contain sliding contact joints or are folded at hinge points and pivot to deploy, often locking into place. The second class consists of on-orbit assembly where a device is fabricated and/or mechanically joined in space to form the structure. The final class is high strain structures (often composed of High strain composites) wherein the device is dramatically flexed from one configuration to another during deployment. Gallery File:Scissor Tower.gif, Scissor-type structure File:Scissor Tower3.gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bay Mud
Bay mud consists of thick deposits of soft, unconsolidated silty clay, which is saturated with water; these soil layers are situated at the bottom of certain estuaries, which are normally in temperate regions that have experienced cyclical glacial cycles. Example locations are Cape Cod Bay, Chongming Dongtan Reserve in Shanghai, China, Banc d'Arguinpreserve in Mauritania, The Bristol Channel in the United Kingdom, Mandø Island in the Wadden Sea in Denmark, Florida Bay, San Francisco Bay, Bay of Fundy, Casco Bay, Penobscot Bay, and Morro Bay. Bay mud manifests low shear strength, high compressibility and low permeability, making it hazardous to build upon in seismically active regions like the San Francisco Bay Area. Typical bulk density of bay mud is approximately 1.3 grams per cubic centimetre. Bay muds often have a high organic content, consisting of decayed organisms at lower depths, but may also contain living creatures when they occur at the upper soil layer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.JPG "Click for more on -> Cardea")
