A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary in size and configuration. Commercial trucks can be large and powerful, may be configured to mount specialized equipment, such as in the case of fire trucks, concrete mixers, suction excavators. Modern trucks are powered by diesel engines, although small to medium size trucks with gasoline engines exist in the US, Mexico. In the European Union, vehicles with a gross combination mass of up to 3.5 t are known as light commercial vehicles, those over as large goods vehicles. Trucks and cars have a common ancestor: the steam-powered fardier Nicolas-Joseph Cugnot built in 1769. However, steam wagons were not common until the mid-1800s; the roads of the time, built for horse and carriages, limited these vehicles to short hauls from a factory to the nearest railway station. The first semi-trailer appeared in 1881, towed by a steam tractor manufactured by De Dion-Bouton. Steam-powered wagons were sold in France and the United States until the eve of World War I, 1935 in the United Kingdom, when a change in road tax rules made them uneconomic against the new diesel lorries.
In 1895 Karl Benz designed and built the first truck in history using the internal combustion engine. That year some of Benz's trucks were modified to become the first bus by the Netphener, the first motorbus company in history. A year in 1896, another internal combustion engine truck was built by Gottlieb Daimler. Other companies, such as Peugeot, Renault and Büssing built their own versions; the first truck in the United States was built by Autocar in 1899 and was available with optional 5 or 8 horsepower motors. Trucks of the era used two-cylinder engines and had a carrying capacity of 3,300 to 4,400 lb. In 1904, 700 heavy trucks were built in the United States, 1000 in 1907, 6000 in 1910, 25000 in 1914. After World War I, several advances were made: pneumatic tires replaced the common full rubber versions. Electric starters, power brakes, 4, 6, 8 cylinder engines, closed cabs, electric lighting followed; the first modern semi-trailer trucks appeared. Touring car builders such as Ford and Renault entered the heavy truck market.
Although it had been invented in 1897, the diesel engine did not appear in production trucks until Benz introduced it in 1923. The diesel engine was not common in trucks in Europe until the 1930s. In the United States, Autocar introduced engines for heavy applications in the mid-1930s. Demand was high enough Autocar launched the "DC" model in 1939. However, it took much longer for diesel engines to be broadly accepted in the US: gasoline engines were still in use on heavy trucks in the 1970s. Truck is used in American English, is common in Canada, New Zealand, Puerto Rico and South Africa, while lorry is the equivalent in British English, is the usual term in countries like the United Kingdom, Malaysia and India; the word "truck" might come from a back-formation of "truckle", meaning "small wheel" or "pulley", from Middle English trokell, in turn from Latin trochlea. Another possible source is the Latin trochus, meaning "iron hoop". In turn, both sources emanate from trekhein; the first known usage of "truck" was in 1611, when it referred to the small strong wheels on ships' cannon carriages.
In its extended usage it came to refer to carts for carrying heavy loads, a meaning known since 1771. Its expanded application to "motor-powered load carrier" has been in usage since 1930, shortened from "motor truck", which dates back to 1901."Lorry" has a more uncertain origin, but has its roots in the rail transport industry, where the word is known to have been used in 1838 to refer to a type of truck a large flat wagon. It derives from the verb lurry of uncertain origin, its expanded meaning, "self-propelled vehicle for carrying goods", has been in usage since 1911. Before that, the word "lorry" was used for a sort of big horse-drawn goods wagon. In the United States and the Philippines "truck" is reserved for commercial vehicles larger than normal cars, includes pickups and other vehicles having an open load bed. In Australia, New Zealand and South Africa, the word "truck" is reserved for larger vehicles. In the United Kingdom, Malaysia, Singapore and Hong Kong lorry is used instead of truck, but only for the medium and heavy types.
Produced as variations of golf cars, with internal combustion or battery electric drive, these are used for off-highway use on estates, golf courses, parks. While not suitable for highway use some variations may be licensed as slow speed vehicles for operation on streets as a body variation of a neighborhood electric vehicle. A few manufactures produce specialized chassis for this type of vehicle, while Zap Motors markets a version of their xebra electric tricycle. Popular in Europe and Asia, many mini trucks are factory redesigns of light automobiles with monocoque bodies. Specialized designs with substantial frames such as the Italian Piaggio shown here are based upon Japanese designs and are popular for use in "old town" sections of European cities that have narrow alleyways. Regardless of name, these smal
Automotive design is the process of developing the appearance, to some extent the ergonomics, of motor vehicles, including automobiles, trucks, buses and vans. The functional design and development of a modern motor vehicle is done by a large team from many different disciplines included within automotive engineering, design roles are not associated with requirements for Professional or Chartered-Engineer qualifications. Automotive design in this context is concerned with developing the visual appearance or aesthetics of the vehicle, though it is involved in the creation of the product concept. Automotive design as a professional vocation is practiced by designers who may have an art background and a degree in industrial design or transportation design. Terminology used in the field is found in the glossary of automotive design; the task of the design team is split into three main aspects: exterior design, interior design, color and trim design. Graphic design is an aspect of automotive design.
Design focuses not only on the isolated outer shape of automobile parts, but concentrates on the combination of form and function, starting from the vehicle package. The aesthetic value will need to correspond to ergonomic utility features as well. In particular, vehicular electronic components and parts will give more challenges to automotive designers who are required to update on the latest information and knowledge associated with emerging vehicular gadgetry dashtop mobile devices, like GPS navigation, satellite radio, HD radio, mobile TV, MP3 players, video playback, smartphone interfaces. Though not all the new vehicular gadgets are to be designated as factory standard items, some of them may be integral to determining the future course of any specific vehicular models; the designer responsible for the exterior of the vehicle develops the proportions and surfaces of the vehicle. Exterior design is first done by a series of manual drawings. Progressively, drawings that are more detailed are executed and approved by appropriate layers of management.
Industrial plasticine and or digital models are developed from, along with the drawings. The data from these models are used to create a full-sized mock-up of the final design. With three- and five-axis CNC milling machines, the clay model is first designed in a computer program and "carved" using the machine and large amounts of clay. In times of high-class 3d software and virtual models on power walls, the clay model is still the most important tool to evaluate the design of a car and, therefore, is used throughout the industry; the designer responsible for the vehicles' interior develops the proportions, shape and surfaces for the instrument panel, door trim panels, pillar trims, etc. Here the emphasis is on the comfort of the passengers; the procedure here is the same as with exterior design. The color and trim designer is responsible for the research and development of all interior and exterior colors and materials used on a vehicle; these include paints, fabric designs, grains, headliner, wood trim, so on.
Color, contrast and pattern must be combined to give the vehicle a unique interior environment experience. Designers work with the exterior and interior designers. Designers draw inspiration from other design disciplines such as: industrial design, home furnishing and sometimes product design. Specific research is done into global trends to design for projects two to three model years in the future. Trend boards are created from this research in order to keep track of design influences as they relate to the automotive industry; the designer uses this information to develop themes and concepts that are further refined and tested on the vehicle models. The design team develops graphics for items such as: badges, dials, kick or tread strips, liveries; the sketches and rendering are transformed into 3D Digital surface modelling and rendering for real-time evaluation with Math data in initial stages. During the development process succeeding phases will require the 3D model developed to meet the aesthetic requirements of a designer and well as all engineering and manufacturing requirements.
The developed CAS digital model will be re-developed for manufacturing meeting the Class-A surface standards that involves both technical as well as aesthetics. This data will be further developed by Product Engineering team; these modelers have a background in Industrial design or sometimes tooling engineering in case of some Class-A modelers. Autodesk Alias and ICEM Surf are the two most used software tools for Class-A development. Several manufacturers have varied development cycles for designing an Automobile, but in practice these are the following. Design and User Research Concept Development sketching CAS Clay modeling Interior Buck Model Vehicle ergonomics Class-A Surface Development Colour and Trim Vehicle GraphicsThe design process occurs concurrently with other product Engineers who will be engineering the styling data for meeting performance and safety regulations. From mid-phase and forth interactions between the designers and product engineers culminates into a finished product be manufacturing ready.
Apart from this the Engineering team parallelly works in the following areas. Product Engineering, NVH Development team, Prototype
Hemispherical combustion chamber
A hemispherical combustion chamber is a type of combustion chamber in a reciprocating internal combustion engine with a domed cylinder head. The hemispherical shape provides a number of advantages over a reverse-flow cylinder head but comes up short in others in carbureted engines. An engine featuring this type of hemispherical chamber is known as a hemi engine. Hemispherical combustion chambers were introduced on some of the earliest automotive engines, shortly after proving the concept of internal combustion engines themselves, their name reflects the concept of a domed cylinder head and the top of the piston enclosing a space that approximates a half of a sphere, although in practice it is less than half. Hemispherical cylinder heads have been used since at least 1901; the Peugeot Grand Prix Car of 1912 and the Alfa Romeo Grand Prix car of 1914 both were four valve engines Daimler, Riley were using hemispherical combustion chambers. Stutz, beginning in 1912, used four-valve engines, conceptually anticipating modern car engines.
Other examples include the BMW double-pushrod design, the Peugeot 403, the Toyota T engine and Toyota V engine, Miller racing engines, the Jaguar XK engine. A hemispherical head gives an efficient combustion chamber with minimal heat loss to the head, allows for two large valves. However, a hemi-head allows no more than two valves per cylinder due to the difficulty in arranging the valve gear for four valves at diverging angles, these large valves are heavier than those in a multi-valve engine of similar valve area, as well as requiring more valve lift; the intake and exhaust valves lie on opposite sides of the chamber and necessitate a "cross-flow" head design. Since the combustion chamber is a hemisphere, a flat-topped piston yields a lower compression ratio unless a smaller chamber is utilized. There is a misconception; this is not true. Some of the modern factory hemi engines that have high compression ratios such as Chrysler's 2009 5.7L engine, 10.5:1 have dome pistons and some of Chrysler's 5.7 engines have flat top pistons.
High compression ratios use 92 - 93 octane gasoline. Theoretically, if the engine required a low compression ratio due to the fact that it is supercharged, flat top pistons can be used or if the goal is to use a lower octane gasoline, flat top pistons can be used. There are many hemi engines with flat top pistons. Desired compression ratio is key in determining piston shape and combustion chamber size along with many other factors such as Combustion chamber volume, Piston compression height, Piston valve relief volume, Piston dome volume, Piston dish volume, Head gasket's thickness, Piston-to-deck clearance. Another example of a hemi flat top piston is the after market Manley Chrysler 6.1L Hemi Flat Top Piston. Significant challenges in the commercialization of engines utilizing hemispherical chambers revolved around the design of the valve actuation, how to make it effective and reliable at an acceptable cost; this complexity was referenced early in Chrysler's development of their 1950s hemi engine: the head was referred to in company advertising as the Double Rocker head.
Although a wedge-head design offers simplified valve actuation, it does so by placing the valves side by side within the chamber, with parallel stem axis. This can restrict the flow of the intake and exhaust into and out of the chamber by limiting the diameters of valve heads to total no more than the bore of the cylinder in a two valve per cylinder arrangement. With a hemispherical chamber with splayed valve stem angle, this limitation is increased by the angle, making the total valve diameter size possible to exceed the bore size within an overhead valve configuration. See IOE engine for another method; the splayed valve angle causes the valve seat plane to be tilted, giving a straighter flow path for the intake and exhaust to/from the port exiting the cylinder head. Engineers have learned that while increasing the valve size with straighter port is beneficial for increasing the maximum power at high rpm, it slows the intake flow speed, not providing the best combustion event for emissions, efficiency, or power in the normal rpm range.
Domed pistons are used to maintain a higher mechanical compression ratio, which tend to increase the flame propagation distance, being detrimental to efficient combustion, unless the number of spark plugs per cylinder is increased. Flame temperatures are high, leading to excessive NOx output which may require exhaust gas recirculation and other emission control measures to meet modern standards; this is one of the main reasons for its decline in popularity. Other drawbacks of the hemispherical chamber include increased production cost and high relative weight; these have pushed the hemi head out of favor in the modern era. Alfa Romeo has produced many successful hemi-head engines throughout the years. Arguably one of their most beloved examples is Giuseppe Busso's original 2.5-liter V6, cited by some as one of the best and most distinctive sounding production engines of all time. Part of this praise is because the hemispherical heads on the original 2-valve engine allowed for an completely straight exhaust port, resulting in a less diluted or muddied engine sound, allowing Alfa Romeo to use quieter stock exhausts without losing much of their distinct and beloved race-bred engine noise.
The Bentley BR.1 was a British rotary aircraft engine of the First World War. Designed by the motor car engine designer W. O. Bentley, the BR.1 was built in large numbers, being one of the main powerplants of the Sopwith Camel. The 130 horsepower Clerget 9B was an important engine for the British Royal Naval Air Service and Royal Flying Corps, being license-produced in Britain and powering a number of important British aircraft, including the Sopwith Camel. However, at £907 a copy it was expensive, prone to overheating, so the Admiralty asked Lieutenant W. O. Bentley, an established pre-war engine designer, to produce a modified version to solve these problems. Bentley came up with his idea of an engine - fitted with aluminium cylinders with cast iron liners, aluminium pistons. Dual ignition was introduced to improve reliability, the stroke increased to 6.7 inches which allowed power to be increased to 150 horsepower. The cost of the engine was reduced, falling to £605 per engine; the resulting engine known as the A.
R.1 for "Admiralty Rotary", but called the BR.1 was manufactured in quantity, although against Admiralty orders. It was standardised for the Camel in RNAS squadrons, but there were never enough to replace the inferior and more expensive Clerget engine in British service, most RFC Camel squadrons continued to use Clerget engines; the BR.1 was developed as the BR.2, a heavier, more powerful engine, which powered, among other types or aircraft, the Camel's eventual replacement, the Sopwith Snipe. Sopwith Camel Avro 536 Westland N.1B Port Victoria P. V.9 Data from Jane's Fighting Aircraft of World War I Type: 9-Cylinder air-cooled rotary engine Bore: 4.72 in, Stroke: 6.69 in Displacement: 1,055.9 cu in Dry weight: 397 lb Cooling system: Air-cooled Power output: 150 bhp at 1,250 rpm Fuel consumption: 11 gallon/hr Oil consumption: 12 pints/hr Power-to-weight ratio: 0.38 bhp/lb Related development Bentley BR2 Comparable engines Clerget 9B Clerget 9Z Gnome Monosoupape 9 Type N Le Rhone 9JRelated lists List of aircraft engines
A carburetor or carburettor is a device that mixes air and fuel for internal combustion engines in the proper air–fuel ratio for combustion. It is sometimes colloquially shortened to carby in Australia. To carburate or carburet means to mix the air and fuel or to equip with a carburetor for that purpose. Carburetors have been supplanted in the automotive and, to a lesser extent, aviation industries by fuel injection, they are still common on small engines for lawn mowers and other equipment. The word carburetor comes from the French carbure meaning "carbide". Carburer means to combine with carbon. In fuel chemistry, the term has the more specific meaning of increasing the carbon content of a fluid by mixing it with a volatile hydrocarbon; the first carburetor was invented by Samuel Morey in 1826. The first person to patent a carburetor for use in a petroleum engine was Siegfried Marcus with his 6 July 1872 patent for a device which mixes fuel with air. A carburetor was among the early patents by Karl Benz as he developed internal combustion engines and their components.
Early carburetors were of the surface type, in which air is combined with fuel by passing over the surface of gasoline. In 1885, Wilhelm Maybach and Gottlieb Daimler developed a float carburetor based on the atomizer nozzle; the Daimler-Maybach carburetor was copied extensively. British courts rejected the Daimler company's claim of priority in favor of Edward Butler's 1884 spray carburetor used on his Petrol Cycle. Hungarian engineers János Csonka and Donát Bánki patented a carburetor for a stationary engine in 1893. Frederick William Lanchester of Birmingham, experimented with the wick carburetor in cars. In 1896, Frederick and his brother built a gasoline-driven car in England, a single cylinder 5 hp internal combustion engine with chain drive. Unhappy with the car's performance and power, they re-designed the engine the following year using two horizontally-opposed cylinders and a newly designed wick carburetor. Carburetors were the common method of fuel delivery for most US-made gasoline engines until the late 1980s, when fuel injection became the preferred method.
This change was dictated by the requirements of catalytic converters and not due to an inherent inefficiency of carburation. A catalytic converter requires that there be more precise control over the fuel / air mixture in order to control the amount of oxygen remaining in the exhaust gases. In the U. S. market, the last cars using carburetors were: 1990: Oldsmobile Custom Cruiser, Buick Estate Wagon, Cadillac Brougham, Honda Prelude, Subaru Justy 1991: Ford Crown Victoria Police Interceptor with the 5.8 L V8 engine. 1991: Jeep Grand Wagoneer with the AMC 360 cu in V8 engine. 1993: Mazda B2200 1994: IsuzuIn Australia, some cars continued to use carburetors well into the 1990s. Low-cost commercial vans and 4WDs in Australia continued with carburetors into the 2000s, the last being the Mitsubishi Express van in 2003. Elsewhere, certain Lada cars used carburetors until 2006. Many motorcycles still use carburetors for simplicity's sake, since a carburetor does not require an electrical system to function.
Carburetors are still found in small engines and in older or specialized automobiles, such as those designed for stock car racing, though NASCAR's 2011 Sprint Cup season was the last one with carbureted engines. In Europe, carburetor-engined cars were being phased out by the end of the 1980s in favor of fuel injection, the established type of engine on more expensive vehicles including luxury and sports models. EEC legislation required all vehicles sold and produced in member countries to have a catalytic converter after December 1992; this legislation had been in the pipeline for some time, with many cars becoming available with catalytic converters or fuel injection from around 1990. However, some versions of the Peugeot 106 were sold with carburettor engines from its launch in 1991, as were versions of the Renault Clio and Nissan Primera and all versions of Ford Fiesta range except the XR2i when it was launched in 1989. Luxury car manufacturer Mercedes-Benz had been producing mechanically fuel-injected cars since the early 1950s, while the first mainstream family car to feature fuel injection was the Volkswagen Golf GTI in 1976.
Ford's first fuel-injected car was the Ford Capri RS 2600 in 1970. General Motors launched its first fuel-injected car in 1957 as an option available for the first generation Corvette. Saab switched to fuel injection across its whole range from 1982; the carburetor works on Bernoulli's principle: the faster air moves, the lower its static pressure, higher the dynamic pressure is. The throttle linkage does not directly control the flow of liquid fuel. Instead, it actuates carburetor mechanisms which meter the flow of air being carried into the engine; the speed of this flow, therefore its pressure, determines the amount of fuel drawn into the airstream. When carburetors are used in aircraft with piston engines, special designs and features are needed to prevent fuel starvation during inverted flight. Engines used an early form of fuel injection known as a pressure carburetor. Most production carbureted engines, as opposed to fuel-injected, h
A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator; the central electrode, which may contain a resistor, is connected by a insulated wire to the output terminal of an ignition coil or magneto. The spark plug's metal shell is screwed into the engine's cylinder head and thus electrically grounded; the central electrode protrudes through the porcelain insulator into the combustion chamber, forming one or more spark gaps between the inner end of the central electrode and one or more protuberances or structures attached to the inner end of the threaded shell and designated the side, earth, or ground electrode. Spark plugs may be used for other purposes. Spark plugs may be used in other applications such as furnaces wherein a combustible fuel/air mixture must be ignited.
In this case, they are sometimes referred to as flame igniters. In 1860 Étienne Lenoir used an electric spark plug in his gas engine, the first internal combustion piston engine. Lenoir is credited with the invention of the spark plug; some sources credit Edmond Berger, an African American believed to have immigrated from Togo, with creating a spark plug in early 1839, though records show he did not receive a patent for his device. Early patents for spark plugs included those by Nikola Tesla, Frederick Richard Simms and Robert Bosch. Only the invention of the first commercially viable high-voltage spark plug as part of a magneto-based ignition system by Robert Bosch's engineer Gottlob Honold in 1902 made possible the development of the spark-ignition engine. Subsequent manufacturing improvements can be credited to Albert Champion, to the Lodge brothers, sons of Sir Oliver Lodge, who developed and manufactured their father's idea and to Kenelm Lee Guinness, of the Guinness brewing family, who developed the KLG brand.
Helen Blair Bartlett played a vital role in making the insulator in 1930. The plug is connected to the high voltage generated by magneto; as current flows from the coil, a voltage develops between the central and side electrodes. No current can flow because the fuel and air in the gap is an insulator, but as the voltage rises further it begins to change the structure of the gases between the electrodes. Once the voltage exceeds the dielectric strength of the gases, the gases become ionized; the ionized gas allows current to flow across the gap. Spark plugs require voltage of 12,000–25,000 volts or more to "fire" properly, although it can go up to 45,000 volts, they supply higher current during the discharge process, resulting in a hotter and longer-duration spark. As the current of electrons surges across the gap, it raises the temperature of the spark channel to 60,000 K; the intense heat in the spark channel causes the ionized gas to expand quickly, like a small explosion. This is the "click" heard when observing a spark, similar to thunder.
The heat and pressure force the gases to react with each other, at the end of the spark event there should be a small ball of fire in the spark gap as the gases burn on their own. The size of this fireball, or kernel, depends on the exact composition of the mixture between the electrodes and the level of combustion chamber turbulence at the time of the spark. A small kernel will make the engine run as though the ignition timing was retarded, a large one as though the timing was advanced. A spark plug is composed of a shell and the central conductor, it passes through the wall of the combustion chamber and therefore must seal the combustion chamber against high pressures and temperatures without deteriorating over long periods of time and extended use. Spark plugs are specified by size, either thread or nut, sealing type, spark gap. Common thread sizes in Europe are 10 mm, 14 mm, 18 mm. In the United States, common thread sizes are 12 mm, 14 mm and 18 mm; the top of the spark plug contains a terminal to connect to the ignition system.
Over of the years variations in the terminal configuration have been introduced by manufacturers. The exact terminal construction varies depending on the use of the spark plug. Most passenger car spark plug wires snap onto the terminal of the plug, but some wires have eyelet connectors which are fastened onto the plug under a nut; the standard solid non-removable nut SAE configuration is common for many trucks. Plugs which are used for these applications have the end of the terminal serve a double purpose as the nut on a thin threaded shaft so that they can be used for either type of connection; this type of spark plug has a removable nut or knurl, which enables its users to attach them to two different kinds of spark plug boots. Some spark plugs have a bare thread, a common type for motorcycles and ATVs. In recent years, a cup-style terminal has been introduced, which allows for a longer ceramic insulator in the same confined space; the main part of t
Gertrude Lawrence was an English actress, singer and musical comedy performer known for her stage appearances in the West End of London and on Broadway in New York. Lawrence was born Gertrude Alice Dagmar Klasen, Alexandra Dagmar Lawrence-Klasen, Gertrude Alexandra Dagmar Klasen or some variant, of English and Danish extraction, in Newington, London, her father was a basso profondo. His heavy drinking led her mother Alice to leave him soon after Gertrude's birth. In 1904, her stepfather took the family to Bognor on the Sussex coast for the August bank holiday. While there, they attended a concert. At her mother's urging, young Gertrude sang a song and was rewarded with a gold sovereign for her effort, it was her first public performance. In 1908, to augment the family's meagre income, Alice accepted a job in the chorus of the Christmas pantomime at Brixton Theatre. A child who could sing and dance was needed to round out the troupe, Alice volunteered her daughter. While working in the production Alice heard of Italia Conti, who taught dance and the rudiments of acting.
Gertrude auditioned for Conti. Lawrence joined Italia Conti's production of. At some point during this period, the child decided to adopt her father's professional surname as her own. Dean cast her in his next production, Gerhart Hauptmann's Hannele, where she first met Noël Coward, their meeting was the start of a close and sometimes tempestuous friendship and arguably the most important professional relationship in both their lives. Following Hannele, Lawrence reconnected with her father, living with a chorus girl, they agreed to let her tour with them in two successive revues, after which Arthur announced he had signed a year-long contract with a variety show in South Africa, leaving the two young women to fend for themselves. Lawrence, now aged sixteen, opted to live at the Theatrical Girls' Club in Soho rather than return to her mother and stepfather, she worked with various touring companies until 1916, when she was hired by impresario André Charlot to understudy Beatrice Lillie and appear in the chorus of his latest production in London's West End.
When it closed, she assumed Lillie's role on tour returned to London once again to understudy the star in another Charlot production, where she met dance director Francis Gordon-Howley. Although he was twenty years her senior, the two wed and soon after had a daughter Pamela, born on May 28, 1918, Lawrence's only child; the marriage was not a success, Lawrence took Pamela with her to her mother's home in Clapham. The couple did not divorce until ten years later. In 1918, either during Lawrence's pregnancy or shortly after she gave birth, she contracted lumbago, she was given two weeks to recuperate by Charlot. He saw Lawrence at an opening night party at Ivor Novello's invitation two days before she was cleared to return to work by her doctor. Charlot fired her; when the apparent reason for her dismissal became common knowledge among other West End theatrical producers, she was unable to find work. In early 1919, Lawrence accepted a job singing in the show at Murray's, a popular London nightclub, where she remained for the better part of the next two years.
While performing there she met a member of the Household Cavalry. He became her friend and lover, taught her how to dress and behave in high society. At the end of 1920, Lawrence left Murray's and began to ease her way back into the legitimate theater while touring in a music hall act as the partner of popular singer Walter Williams. In October 1921, Charlot asked her to replace an ailing Beatrice Lillie as star of his latest production, A to Z, opposite Jack Buchanan. In it the two introduced the song "Limehouse Blues," which went on to become one of Lawrence's signature tunes. In 1923, Noël Coward developed his first musical revue, London Calling! for Lawrence. Charlot agreed to produce it, but brought in more experienced writers and composers to work on the book and score. One of Coward's surviving songs was "Parisian Pierrot", a tune that would be identified with Lawrence throughout her career; the show's success led its producer to create André Charlot's London Revue of 1924, which he took to Broadway with Lawrence, Lillie and Constance Carpenter.
It was so successful it moved to a larger theatre to accommodate the demand for tickets and extended its run. After it closed, the show toured the United States and Canada, although Lawrence was forced to leave the cast when she contracted double pneumonia and pleurisy and was forced to spend fourteen weeks in a Toronto hospital recuperating. Charlot's Revue of 1926, starring Lawrence and Buchanan, opened on Broadway in late 1925. In his review, Alexander Woollcott singled out Lawrence, calling her "the personification of style and sophistication" and "the ideal star." Like its predecessor, it toured following the Broadway run. It proved to be Lawrence's last project with Charlot. In November 1926, she became the first British performer to star in an American musical on Broadway when she opened in Oh, Kay!, with music by George Gershwin, lyrics by Ira Gershwin, a book by Guy Bolton and P. G. Wodehouse. Following a run of 256 performances, the musical opened in the West End, where it ran