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Modular Propeller
Unlike a standard one-piece boat or aircraft propeller, a modular propeller is made up of using a number of replaceable parts, typically: * a set of matched blades; * a propeller hub; and * an end cap to retain the blades and to secure the propeller as a solid unit. Modular propellers may be fitted to aircraft as well as boats. The benefits of a modular propeller are that its specifications (such as blade pitch or propeller diameter) may be altered to suit varying conditions; and it becomes much easier to replace damaged elements, such as a broken blade. Traditional one-piece propellers may be professionally modified to change the blade pitch, but this is not a common or easy option. In contrast, a modular propeller allows changes to be made quickly and easily. A modular propeller may have, for instance, a metal hub but composite blades. One patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or sel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from stern sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arplast Helice
Arplast Helice is a former French manufacturer of propellers for light aircraft and microlights. The company was based at Gargas, France. The company appears to have been wound up on 29 April 2015. The firm's main product was the composite 3-bladed "Ecoprop", which can be fixed, ground-adjustable, in-flight adjustable, or automatically folding. The Ecoprop modular propellers are lightweight, have a very slim profile and are very efficient. Also, the firm once produced its own microlight aircraft, the Arplast Micro'B. Arplast propellers have been fitted, ''(inter alia)'', to the following aircraft: * ARV Super2 * Barber Snark The Barber Snark is an innovative two-seater kit-plane, designed and built in New Zealand by Bill Barber. It first flew in late 1987. At least six aircraft have been built, and some of these have varying specifications, such as different ... See also Le Dauphiné article - http://www.ledauphine.com/economie-et-finance/2013/12/03/le-conc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground-adjustable Propeller
A ground-adjustable propeller is a simple type of aircraft variable-pitch propeller where the blade angle can be adjusted between pre-set limits of fine and coarse pitch.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 86. Aviation Supplies & Academics, 1997. As its name implies, a ground-adjustable propeller may be adjusted only when the aircraft is on the ground and when the engine is not running. Ground-adjustable propellers, which are mostly used on light and very light aircraft, are much cheaper and lighter than more sophisticated and versatile in-flight-adjustable propellers. A ground-adjustable propeller allows pitch changes to be made, although not in flight, to optimise the aircraft for current payload and flying conditions. Adjustment To adjust the propeller, the blades are loosened in the hub, a new angle set and then the hub tightened. The process is one of compromise, and of trial & error. After a flight, if, say, climb seemed too sluggish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blade Pitch
Blade pitch or simply pitch refers to the angle of a blade in a fluid. The term has applications in aeronautics, shipping, and other fields. Aeronautics In aeronautics, blade pitch refers to the angle of the blades of an aircraft propeller or helicopter rotor. Blade pitch is measured relative to the aircraft body. It is usually described as "fine" or "low" for a more vertical blade angle, and "coarse" or "high" for a more horizontal blade angle. Blade pitch is normally described as a ratio of forward distance per rotation assuming no slip. Blade pitch acts much like the gearing of the final drive of a car. Low pitch yields good low speed acceleration (and climb rate in an aircraft) while high pitch optimizes high speed performance and fuel economy. It is quite common for an aircraft to be designed with a variable-pitch propeller, to give maximum thrust over a larger speed range. A fine pitch would be used during take-off and landing, whereas a coarser pitch is used for high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Material
A composite or composite material (also composition material) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or physical properties and are merged to create a material with properties unlike the individual elements. Within the finished structure, the individual elements remain separate and distinct, distinguishing composites from mixtures and solid solutions. Composite materials with more than one distinct layer are called ''composite laminates''. Typical engineered composite materials are made up of a binding agent forming the ''matrix'' and a Filler (materials), filler material (particulates or fibres) giving ''substance'', e.g.: * Concrete, reinforced concrete and masonry with cement, lime or Mortar (masonry), mortar (which is itself a composite material) as a binder * Composite wood such as glulam and plywood with wood glue as a binder * Reinforced plastics, such as fiberglass and fibre-rein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclosure of the invention."A patent is not the grant of a right to make or use or sell. It does not, directly or indirectly, imply any such right. It grants only the right to exclude others. The supposition that a right to make is created by the patent grant is obviously inconsistent with the established distinctions between generic and specific patents, and with the well-known fact that a very considerable portion of the patents granted are in a field covered by a former relatively generic or basic patent, are tributary to such earlier patent, and cannot be practiced unless by license thereunder." – ''Herman v. Youngstown Car Mfg. Co.'', 191 F. 579, 584–85, 112 CCA 185 (6th Cir. 1911) In most countries, patent rights fall under private la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propellers
A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from stern sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Transport
Maritime transport (or ocean transport) or more generally waterborne transport, is the transport of people (passengers or goods (cargo) via waterways. Freight transport by watercraft has been widely used throughout recorded history, as it provides a higher-capacity mode of transportation for passengers and cargo than land transport, the latter typically being more costly per unit payload due to it being affected by terrain conditions and road/rail infrastructures. The advent of aviation during the 20th century has diminished the importance of sea travel for passengers, though it is still popular for short trips and pleasure cruises. Transport by watercraft is much cheaper than transport by aircraft or land vehicles (both road and rail), but is significantly slower for longer journeys and heavily dependent on adequate port facilities. Maritime transport accounts for roughly 80% of international trade, according to UNCTAD in 2020. Maritime transport can be realized over any ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
