|
Stairclimber
A stairclimber is a type of trolley fitted with rotating wheels or tracks so that it can be pushed or pulled up or down steps or a stairway. Stairclimbers can be manual or battery-powered, and are commonly found in wheel, track, push arm or walker variants. Powered electric stair climbers are available in many variants, both in manufacture and mechanical operation, with the most common being push arm and walker variants due to size, speed and mobility. Tracked versions offer the greatest S.W.L (safe working limit) with regards to the load being moved, whilst push arm and walker variants offer greater speed and ease of operation. Manual Stairclimber wheels Manual stairclimber wheels can be fitted to hand trucks (sack trucks) and as the name implies, are designed to aid the moving of goods up or down stairs. This type of stairclimber relies on a wheel configuration known as tri-star, three wheels set into a triangle configuration replacing the standard wheel on either side. Stair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stairclimber
A stairclimber is a type of trolley fitted with rotating wheels or tracks so that it can be pushed or pulled up or down steps or a stairway. Stairclimbers can be manual or battery-powered, and are commonly found in wheel, track, push arm or walker variants. Powered electric stair climbers are available in many variants, both in manufacture and mechanical operation, with the most common being push arm and walker variants due to size, speed and mobility. Tracked versions offer the greatest S.W.L (safe working limit) with regards to the load being moved, whilst push arm and walker variants offer greater speed and ease of operation. Manual Stairclimber wheels Manual stairclimber wheels can be fitted to hand trucks (sack trucks) and as the name implies, are designed to aid the moving of goods up or down stairs. This type of stairclimber relies on a wheel configuration known as tri-star, three wheels set into a triangle configuration replacing the standard wheel on either side. Stair ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tri-star (wheel Arrangement)
The tri-star is a novel wheel design—originally by Robert and John Forsyth, assigned to Lockheed in 1967—in which three wheels are arranged in an upright triangle with two on the ground and one above them. If either of the wheels in contact with the ground gets stuck, the whole system rotates over the obstruction. Design In the tri-star wheel, all three satellite wheels are simultaneously powered through a mechanical linkage between each satellite wheel and a shaft concentric with the central hub. In the original patent, the direction of the vehicle is controlled through the differential steering. Applications Lockheed modified an M2A2 105mm Light Howitzer and produced it from 1969-1977 with a drive unit and tri-star wheel system into an Auxiliary Propelled Howitzer they termed "Terra Star." The only surviving prototype is located at the Rock Island Arsenal Museum. Its most famous application was the Landmaster, a unique armoured personnel carrier (APC) from the 1977 film ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Truck
:''"Hand truck" may also refer to Pallet jack.'' A hand truck, also known as a hand trolley, dolly, stack truck, trundler, box cart, sack barrow, cart, sack truck, two wheeler, or bag barrow, is an L-shaped box-moving handcart with handles at one end, wheels at the base, with a small ledge to set objects on, flat against the floor when the hand-truck is upright. The objects to be moved are tilted forward, the ledge is inserted underneath them, and the objects allowed to tilt back and rest on the ledge. The truck and objects are then tilted backward until the weight is balanced over the wheels, making otherwise bulky and heavy objects easier to move. It is a first-class lever. Overview Sack trucks were originally used in the 18th century to move large sacks of spices on docks by young boys, from the age of 11, who were unable to lift the large sacks by hand. By using this method they were able to work as well as grown men in moving items around. Later, such trucks were amended for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handtruck
:''"Hand truck" may also refer to Pallet jack.'' A hand truck, also known as a hand trolley, dolly, stack truck, trundler, box cart, sack barrow, cart, sack truck, two wheeler, or bag barrow, is an L-shaped box-moving cart, handcart with handles at one end, wheels at the base, with a small ledge to set objects on, flat against the floor when the hand-truck is upright. The objects to be moved are tilted forward, the ledge is inserted underneath them, and the objects allowed to tilt back and rest on the ledge. The truck and objects are then tilted backward until the weight is balanced over the wheels, making otherwise bulky and heavy objects easier to move. It is a lever#Classes of levers, first-class lever. Overview Sack trucks were originally used in the 18th century to move large sacks of spices on docks by young boys, from the age of 11, who were unable to lift the large sacks by hand. By using this method they were able to work as well as grown men in moving items around. Late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cart
A cart or dray (Australia and New Zealand) is a vehicle designed for transport, using two wheels and normally pulled by one or a pair of draught animals. A handcart is pulled or pushed by one or more people. It is different from the flatbed trolley also known as a dray, (for freight) or wagon, which is a heavy transport vehicle with four wheels and typically two or more humans. Over time, the term "cart" has come to mean nearly any small conveyance, including shopping carts, golf carts, gokarts, and UTVs, without regard to number of wheels, load carried, or means of propulsion. The draught animals used for carts may be horses, donkeys or mules, oxen, and even smaller animals such as goats or large dogs. History Carts have been mentioned in literature as far back as the second millennium B.C. Handcarts pushed by humans have been used around the world. In the 19th century, for instance, some Mormons traveling across the plains of the United States between 1856 and 1860 use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stairway
Stairs are a structure designed to bridge a large vertical distance between lower and higher levels by dividing it into smaller vertical distances. This is achieved as a diagonal series of horizontal platforms called steps which enable passage to the other level by stepping from one to another step in turn. Steps are very typically rectangular. Stairs may be straight, round, or may consist of two or more straight pieces connected at angles. Types of stairs include staircases (also called stairways), ladders, and escalators. Some alternatives to stairs are elevators (also called lifts), stairlifts, inclined moving walkways, and ramps. A stairwell is a vertical shaft or opening that contains a staircase. A flight (of stairs) is an inclined part of a staircase consisting of steps (and their lateral supports if supports are separate from steps). Components and terms A ''stair'', or a ''stairstep'', is one step in a flight of stairs.R.E. Putnam and G.E. Carlson, ''Architectural a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Continuous Track
Continuous track is a system of vehicle propulsion used in tracked vehicles, running on a continuous band of treads or track plates driven by two or more wheels. The large surface area of the tracks distributes the weight of the vehicle better than steel or rubber tires on an equivalent vehicle, enabling continuous tracked vehicles to traverse soft ground with less likelihood of becoming stuck due to sinking. Modern continuous tracks can be made with soft belts of synthetic rubber, reinforced with steel wires, in the case of lighter agricultural machinery. The more common classical type is a solid chain track made of steel plates (with or without rubber pads), also called caterpillar tread or tank tread, which is preferred for robust and heavy construction vehicles and military vehicles. The prominent treads of the metal plates are both hard-wearing and damage resistant, especially in comparison to rubber tyres. The aggressive treads of the tracks provide good trac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Conditioning
Air conditioning, often abbreviated as A/C or AC, is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as 'comfort cooling') and in some cases also strictly controlling the humidity of internal air. Air conditioning can be achieved using a mechanical 'air conditioner' or alternatively a variety of other methods, including passive cooling or ventilative cooling. Air conditioning is a member of a family of systems and techniques that provide heating, ventilation, and air conditioning (HVAC). Heat pumps are similar in many ways to air conditioners, but use a reversing valve to allow them to both heat and also cool an enclosed space. Air conditioners, which typically use vapor-compression refrigeration, range in size from small units used within vehicles or single rooms to massive units that can cool large buildings. Air source heat pumps, which can be used for heating as well as cooling, are becoming incre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screw Thread
A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a ''straight'' thread and the latter called a ''tapered'' thread. A screw thread is the essential feature of the screw as a simple machine and also as a threaded fastener. The mechanical advantage of a screw thread depends on its ''lead'', which is the linear distance the screw travels in one revolution. In most applications, the lead of a screw thread is chosen so that friction is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied, as long as no external rotational force is present. This characteristic is essential to the vast majority of its uses. The tightening of a fastener's screw thread is comparable to driving a wedge into a gap until it sticks fast thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vending Machine
A vending machine is an automated machine that provides items such as snacks, beverages, cigarettes, and lottery tickets to consumers after cash, a credit card, or other forms of payment are inserted into the machine or otherwise made. The first modern vending machines were developed in England in the early 1880s and dispensed postcards. Vending machines exist in many countries and, in more recent times, specialized vending machines that provide less common products compared to traditional vending machine items have been created. History The earliest known reference to a vending machine is in the work of Hero of Alexandria, an engineer, and mathematician in first-century Roman Egypt. His machine accepted a coin and then dispensed holy water. When the coin was deposited, it fell upon a pan attached to a lever. The lever opened a valve which let some water flow out. The pan continued to tilt with the weight of the coin until it fell off, at which point a counterweight snapped th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcade Machines
An arcade cabinet, also known as an arcade machine or a coin-op cabinet or coin-op machine, is the housing within which an arcade game's electronic hardware resides. Most cabinets designed since the mid-1980s conform to the Japanese Amusement Machine Manufacturers Association (JAMMA) wiring standard. Some include additional connectors for features not included in the standard. Parts of an arcade cabinet Because arcade cabinets vary according to the games they were built for or contain, they may not possess all of the parts listed below: *A display output, on which the game is displayed. They may display either raster or vector graphics, raster being most common. Standard resolution is between 262.5 and 315 vertical lines, depending on the refresh rate (usually between 50 and 60 Hz). Slower refresh rates allow for better vertical resolution. Monitors may be oriented horizontally or vertically, depending on the game. Some games use more than one monitor. Some newer cabinets h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safe
A safe (also called a strongbox or coffer) is a secure lockable box used for securing valuable objects against theft or fire. A safe is usually a hollow cuboid or cylinder, with one face being removable or hinged to form a door. The body and door may be cast from metal (such as steel) or formed out of plastic through blow molding. Bank teller safes typically are secured to the counter, have a slit opening for dropping valuables into the safe without opening it, and a time-delay combination lock to foil thieves. One significant distinction between types of safes is whether the safe is secured to a wall or structure or if it can be moved around. A less secure version (only suitable for petty cash) is usually called a cash-box. History The first known safe dates back to the 13th century BC and was found in the tomb of Pharaoh Ramesses II. It was made of wood and consisted of a locking system resembling the modern pin tumbler lock. In the 16th century, blacksmiths in souther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
